CN114713134A - Production process of cellulose mixed ether by gas-solid method - Google Patents

Abstract

The invention relates to a gas-solid production process for cellulose mixed ether, which comprises the following steps: pulverizing: pulverizing cotton pulp or wood pulp; Ethane and dimethyl ether are added to the reaction kettle, and the temperature is raised to 40-70°C at a constant speed to carry out alkalization etherification reaction; Separation and recovery, adding hydrochloric acid to the remaining material for neutralization; Refining: After neutralization, add water to the material for washing, then filter, rinse, steam filter through a continuous washing centrifugal filter, and finally pulverize and dry to obtain the finished product Cellulose mixed ethers. In the invention, an auxiliary stirring device is added to the reaction kettle, so as to improve the stirring efficiency and further improve the efficiency of cellulose alkalization and etherification. The methyl chloride, ethylene oxide and dimethyl ether that are participating in the reaction are separated, recovered and reused by the separation device.

Description

Production process of cellulose mixed ether by gas-solid method

technical field

The invention belongs to the technical field of cellulose mixed ether production, and in particular relates to a gas-solid production process for the cellulose mixed ether.

Background technique

Cellulose mixed ethers refer to ethers with two different substituents on the cellulose ether molecular chain. Due to the combination of the properties of two different cellulose ethers, it can give full play to the performance of cellulose ethers more comprehensively, and its solubility, dispersibility, transparency, enzyme resistance, and salt resistance are better than single ethers. Widely used in many industrial fields and daily life.

The production technology of cellulose mixed ether mainly includes gas-solid method and solid-liquid method (solvent method). The gas-solid method is to inject ethylene oxide, methyl chloride and a certain amount of dimethyl ether as etherifying agents into a liquid state under high pressure during etherification, and then inject them into the reactor to directly react with alkali cellulose.

In the existing gas-solid method, methyl chloride, ethylene oxide, and dimethyl ether are consumed in large quantities, and some of those that do not participate in the reaction are also emptied and are wasted in other forms, which cannot be fully utilized.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a cellulose mixed ether gas-solid production process. The present invention adds an auxiliary stirring device in the reaction kettle to improve the stirring efficiency and further improve the cellulose alkali. Efficiency of etherification. The methyl chloride, ethylene oxide and dimethyl ether that are participating in the reaction are separated, recovered and reused by the separation device.

The technical scheme adopted by the present invention to solve the problems existing in the prior art is:

The production process of cellulose mixed ether gas-solid method includes the following steps:

A. Pulverization: pulverize cotton pulp or wood pulp to obtain powdery cellulose with a particle size of 200-230 μm and a bulk density of 180-200 g/L;

B. Alkalization and etherification: add powdery cellulose and lye into the reaction kettle, then inject high-pressure nitrogen into the reaction kettle for boosting, the pressure rises to 2.3MPa, and then add high-pressure liquid methyl chloride and ethylene oxide With dimethyl ether, the temperature is uniformly heated to 40-70 ℃, and the basification etherification reaction is carried out;

C, neutralization: after the reaction is finished, the pressure relief is carried out to the reactor, and the unreacted methyl chloride, ethylene oxide and dimethyl ether are vaporized and discharged into the separation device for separation and recovery; the remaining materials are discharged from the reactor , and then add hydrochloric acid for neutralization, so that the pH value of the material is maintained between 6-8;

D. Refining: After neutralization, add water to the material for washing, then filter, rinse, steam filter through a continuous washing centrifugal filter, and finally pulverize and dry to obtain the finished cellulose mixed ether.

Preferably, the reaction kettle described in step B comprises a reaction kettle tank body with an open upper end, a reaction kettle upper cover and a stirring paddle provided above the reaction kettle tank body.

The bottom of the reactor tank is provided with a discharge port, and the discharge port is provided with a valve.

A first feed pipe, a second feed pipe, a booster pipe and a pressure relief pipe are connected through the top of the upper cover of the reactor.

The first feed pipe is provided with a stop valve.

The second feed pipe is respectively connected with the methyl chloride supply pipeline, the ethylene oxide supply pipeline and the dimethyl ether supply pipeline through valves.

The booster pipe is connected to the nitrogen supply line.

The pressure relief pipe is connected through the separation device.

The stirring paddle includes a paddle shaft, which is coaxially arranged inside the reactor tank body, a paddle is fixed on the paddle shaft, and the upper end of the paddle shaft is penetrated to the outside of the upper cover of the reactor and is fixed with a first conical gear.

A first motor is fixed on the upper cover of the reaction kettle, and the first motor drives the first star-chasing gear to rotate.

Preferably, the tank body of the reaction kettle is a cylindrical area, a circular platform area and a feeding pipe arranged coaxially from top to bottom in sequence, and the vertical cross-sectional shape of the circular platform area is a circular cone shape with an upper end diameter larger than a lower end diameter, and the feeding pipe The inner diameter is the same as the inner diameter of the lower end of the circular truncated area, and the inner diameter of the cylindrical area is the same as the inner diameter of the upper end of the circular truncated area.

The opening of the lower end of the feeding pipe is provided with a plug-in valve.

The paddle shaft is tubular, a central shaft is coaxially penetrated inside the paddle shaft, a ring-shaped support plate is sleeved on the circumferential surface of the central shaft, the support plate is located in the round table area, and the lower end of the paddle shaft is rotatably connected with the support plate

The central shaft is wound with a spiral sheet on the circumferential surface below the support plate, the spiral sheet is inserted inside the feeding tube, and the outer diameter of the spiral sheet is the same as the inner diameter of the feeding tube.

The upper end of the central shaft is penetrated to the outside of the upper cover of the reaction kettle, and a second bevel gear is fixed.

The output shaft of the first motor drives the second bevel gear to rotate.

Preferably, a bottom shaft is fixed at the lower end of the central shaft, a ring groove is concavely formed on the circumferential surface of the bottom shaft, a sleeve ring is rotatably sleeved inside the ring groove, and the circumferential surface of the sleeve ring and the inner wall of the feeding pipe are fixed by several Rod fixed connection.

Preferably, a toothed ring is arranged on the inner wall of the reaction kettle tank.

A number of auxiliary stirring devices are arranged in the interior of the reactor tank and are distributed in an annular array around its axis.

The auxiliary stirring device includes a rotating shaft, a blade and a first gear. One end of the rotating shaft is inserted into the paddle shaft or the inner wall of the paddle, and the other end is fixedly connected with the first gear.

Several blades are fixedly connected to the circumferential surface of the rotating shaft

The rotating shaft is rotatably connected with the paddle shaft or the paddle, the first gear is arranged on the gear ring, and the first gear is meshed and connected with the gear ring.

Preferably, a driving mechanism is provided above the upper cover of the reaction kettle.

The driving mechanism includes a first transmission rod, a second transmission rod, a third transmission rod, a fourth transmission rod, a fifth transmission rod and a regulating device.

The first transmission rod includes a third bevel gear and a first pulley that are coaxially and fixedly connected through a rotating rod.

The second transmission rod includes a fourth bevel gear, a second pulley and a third pulley that are coaxially and fixedly connected through a rotating rod.

The third transmission rod includes a driven gear, a fourth pulley, a second gear and a third gear that are coaxially and fixedly connected through a rotating rod.

The fourth transmission rod includes a fifth pulley and a fourth gear that are coaxially and fixedly connected through a rotating rod.

The fifth transmission rod includes a sixth pulley and a fifth gear that are coaxially and fixedly connected through a rotating rod.

The control device includes a vertically arranged second telescopic rod, a vertical rod, an upper roller and a lower roller, the lower end of the vertical rod is fixedly connected with the top end of the telescopic part of the second telescopic rod, the upper roller and the lower roller are respectively arranged up and down on both sides of the vertical rod, the upper The axis of the roller and the lower roller are arranged horizontally.

The third bevel gear is meshed with the second bevel gear, and the first pulley and the fifth pulley are connected by a first timing belt.

The fourth bevel gear is meshed with the first bevel gear, the second pulley and the fourth pulley are connected by a second timing belt, and the third pulley and the sixth pulley are connected by a third timing belt.

The vertical rod is arranged between the second synchronous belt and the third synchronous belt, the upper roller is located just above the second synchronous belt, and the lower roller is located just below the third synchronous belt.

When the upper roller is not in contact with the second synchronous belt, the second synchronous belt is in a slack state.

When the lower roller is not in contact with the third synchronous belt, the third synchronous belt is in a slack state.

The driven gear is meshed with the driving gear on the output shaft of the first motor, the second gear is meshed with the fifth gear, and the third gear is meshed with the fourth gear.

Preferably, the separation device includes three liquefaction tanks, and the three liquefaction tanks are respectively used for liquefying ethylene oxide, methyl chloride and dimethyl ether.

The liquefaction box includes a first box body, the inner cavity of the first box body is a cuboid, the inner wall of the first box body in the length direction is provided with a serpentine refrigeration pipe, and the inlet and outlet of the serpentine refrigeration pipe are penetrated to the first box. The outside of the body is connected to the pipeline of the refrigeration unit.

The outside of the first box body is provided with an air intake pipe and an exhaust pipe that are connected to its inner cavity, a drainage groove is concave in the bottom of the first box body, a drainage pipe is connected through the bottom of the drainage groove, and the end of the drainage pipe passes through. Set to the outside of the first box.

There is a valve on the drain groove or drain pipe.

The inlet pipe of the liquefaction tank for liquefying ethylene oxide is connected through the pressure relief pipe of the reactor.

The exhaust pipe of the liquefaction tank for liquefying ethylene oxide is penetratingly connected to the intake pipe for the liquefaction tank for liquefying methyl chloride.

The exhaust pipe of the liquefaction tank for liquefying methyl chloride is penetratingly connected to the intake pipe for the liquefaction tank for liquefying dimethyl ether.

The exhaust pipe of the liquefaction tank for liquefying the dimethyl ether is connected through the nitrogen recovery pipe.

Preferably, a piston is vertically arranged inside the first box body, and the end faces around the piston are in contact with the inner wall of the first box body.

At least two screws are arranged inside the first box along the length direction. The screws pass through the piston, and the screws are connected with the piston in a thread. One end of the screw is inserted into the inner wall of the first box, and the other end is inserted outside the first box and fixed. A seventh pulley is connected.

A second motor is fixed outside the first box, an eighth pulley is fixed on the output shaft of the second motor, and the eighth pulley is connected with all the seventh pulleys through the same fourth synchronous belt.

Preferably, the intake pipe and the exhaust pipe are connected to the side wall of one end of the first box in the length direction.

A through hole is provided on the side wall of the other end in the length direction of the first box body.

One end of the piston facing the through hole is fixed with a rubber sleeve, and the rubber sleeve is threadedly connected with the screw rod.

Preferably, an air box is provided outside the liquefaction tank, and the air box includes a second box body with an open upper end.

The upper opening of the second box body is covered with an elastic sealing gasket, and the elastic sealing gasket is fixedly connected with the second box body through the fixing frame.

A test tube is penetratingly connected to the outside of the second box body, the test tube is provided with a stop valve, and the through hole is penetratingly connected to the second box body through a connecting air passage.

Compared with the prior art, the present invention has the following beneficial effects:

(1) A one-step alkalization etherification reaction is adopted, and a uniform temperature rise is adopted in the reaction process. Compared with the two-stage heating of the conventional process, the etherification substitution uniformity is better, and the product properties are more uniform and stable.

(2) A certain amount of dimethyl ether is added as an inhibitor during the alkalization etherification reaction, which makes the reaction more uniform and suppresses the occurrence of side reactions, and at the same time improves the utilization rate of the etherification agent.

(3) The rotating shaft of the auxiliary stirring device inside the reaction kettle and the rotating shaft of the stirring paddle are perpendicular to each other, thereby changing the flow of materials in the reaction kettle, improving the stirring efficiency, and then improving the alkalization and etherification efficiency of cellulose.

(4) There are equal-diameter spiral slices inside the feeding tube, and the discharging effect is better through the spiral slices.

(5) The unreacted methyl chloride, ethylene oxide and dimethyl ether are recovered and separated through the separation device, and then used.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the partial flow chart of cellulose mixed ether gas-solid method production process of the present invention,

Fig. 2 is the refrigeration system flow chart in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 3 is the outline drawing of the reactor in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 4 is the exploded view of the reactor reactor in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 5 is a partial enlarged view of part A in Fig. 4,

Fig. 6 is the first sectional view of the reactor in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 7 is the second sectional view of the reactor in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 8 is a partial enlarged view of B in Fig. 7,

Fig. 9 is the horizontal cross-sectional view of the reactor discharging pipe in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 10 is the horizontal sectional view of the reactor flap valve in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 11 is a longitudinal sectional view of Fig. 9,

Fig. 12 is a partial enlarged view of C in Fig. 11,

Fig. 13 is the structure diagram of reactor stirring paddle and driving mechanism in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 14 is the outline drawing of the stirring paddle of the reactor in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 15 is the outline drawing of the reaction kettle driving mechanism in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 16 is the first outline drawing of the separation device in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 17 is the second outline drawing of the separation device in the cellulose mixed ether gas-solid production process of the present invention,

Figure 18 is an exploded view of the gas box in the separation device in the cellulose mixed ether gas-solid production process of the present invention,

19 is a sectional view of the liquefaction tank shell in the separation device in the cellulose mixed ether gas-solid production process of the present invention,

Fig. 20 is a partial enlarged view of D in Fig. 19,

21 is a sectional view of the liquid level sensor of the liquefaction tank in the separation device in the cellulose mixed ether gas-solid production process of the present invention,

Figure 22 is a sectional view at the piston of the liquefaction tank in the separation device in the cellulose mixed ether gas-solid production process of the present invention,

Figure 23 is the outline drawing of the cooling pipe inside the liquefaction tank in the separation device in the cellulose mixed ether gas-solid production process of the present invention,

Figure 24 is a diagram showing the connection effect of the piston and its driving mechanism of the liquefaction tank in the separation device in the cellulose mixed ether gas-solid production process of the present invention.

In the picture: 1-Reactor tank body, 101-Feed pipe, 1011-Sleeve ring, 1012-Fixing rod, 102-Valve body, 1021-Slot, 103-Round table area, 2-Reaction kettle upper cover, 201- First feed pipe, 202-second feed pipe, 203-boost pipe, 204-pressure relief pipe, 3-paddle shaft, 301-paddle, 302-first bevel gear, 4-auxiliary stirring device, 401-rotating shaft, 402-blade, 403-first gear, 5-gear ring, 501-limiting ring, 6-spiral plate, 601-bottom shaft, 602-ring groove, 603-central shaft, 604-second cone Shape gear, 605-support plate, 7-insert plate, 701-first telescopic rod, 8-first motor, 801-drive gear, 9-first transmission rod, 901-third bevel gear, 902-first Pulley, 10-second transmission rod, 1001-fourth bevel gear, 1002-second pulley, 1003-third pulley, 11-third transmission rod, 1101-driven gear, 1102-fourth pulley, 1103- Second gear, 1104-third gear, 12-fourth transmission rod, 1201-fifth pulley, 1202-fourth gear, 13-fifth transmission rod, 1301-sixth pulley, 1302-fifth gear, 14- Control device, 1401-second telescopic rod, 1402-vertical rod, 1403-upper roller, 1404-lower roller, 15-first timing belt, 16-second timing belt, 17-third timing belt, 18-protective cover ;

19-First box, 1901-Guide rod, 1902-Through hole, 1903-Drain groove, 1904-Through cavity, 20-Piston, 2001-Rubber sleeve, 21-Screw, 2101-Seventh pulley, 22- The second motor, 2201- the eighth pulley, 2202- the fourth synchronous belt, 23- serpentine refrigeration pipe, 24- intake pipe, 25- exhaust pipe, 26- lift valve, 27- drain pipe, 28- electronic liquid bit meter;

29-air box, 2901-second box, 2902-elastic gasket, 2903-fixing frame, 2904-test tube, 30-connecting airway;

31-nitrogen tank, 32-intermediate tank, 33-storage tank, 34-common refrigeration unit, 35-standby refrigeration unit, 36-temperature sensor, 37-electrically controlled three-way valve;

01-nitrogen gas inlet pipe, 02-nitrogen gas return pipe, 03-connecting gas pipe, 04-first liquid collection pipe, 05-second liquid collection pipe, 06-first liquid inlet pipe, 07-second liquid inlet pipe, 08 - the third liquid inlet pipe;

001-low temperature box refrigerant discharge pipe, 002-refrigerant reuse pipe, 003-high temperature box refrigerant inlet pipe, 004-high temperature box refrigerant discharge pipe, 005- common unit refrigerant return pipe, 006-low temperature box refrigerant supply pipe, 007- Low temperature box refrigerant bypass discharge pipe, 008-standby unit refrigerant discharge pipe, 009-high temperature box backup refrigerant supply pipe, 0011-high temperature box standby refrigerant return branch pipe, 0012-high temperature box refrigerant return pipe, 0013-standby unit refrigerant return pipe , 0014- low temperature box standby refrigerant supply main pipe, 0015- low temperature box standby refrigerant supply branch pipe, 0016- low temperature box standby refrigerant return pipe.

Detailed ways

As used in the specification and claims, certain terms are used to refer to particular components. It should be understood by those skilled in the art that hardware manufacturers may refer to the same component by different nouns. The description and claims do not use the difference in name as a way to distinguish components, but use the difference in function of the components as a criterion for distinguishing. As mentioned in the entire specification and claims, "comprising" is an open-ended term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range, and basically achieve the technical effect.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", horizontal" etc. is based on the accompanying drawings The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a reference to the present invention. limits.

In the present invention, unless otherwise expressly specified and limited, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrally connected; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

The cellulose mixed ether gas-solid production process of the present invention will be further described in detail below with reference to the accompanying drawings, but it is not intended to limit the present invention.

The production process of cellulose mixed ether gas-solid method includes the following steps:

A. Pulverization: Pulverize cellulose pulp such as cotton pulp or wood pulp to obtain powdery cellulose with a particle size of 200-230 μm and a bulk density of 180-200 g/L.

B. Alkalization and etherification: add powdery cellulose and lye into the reaction kettle, then inject high-pressure nitrogen into the reaction kettle for boosting, the pressure rises to 2.3MPa, and then add high-pressure liquid methyl chloride and ethylene oxide and dimethyl ether, heated to 40-70 ℃ at a constant speed, in this embodiment, the temperature inside the reactor was heated to 70 ℃ at a constant speed, the heating time was 1.5h, the temperature was kept for 1.5h, and the alkalization etherification reaction was carried out;

The raw material ratio is powdered cellulose: methyl chloride: ethylene oxide: lye: dimethyl ether=1:(0.6-1.2):(0.15-0.35):(1.3-1.6):(0.6-0.8) , In this embodiment, the weights of powdered cellulose, methyl chloride, ethylene oxide, lye (sodium hydroxide solution with a concentration of 50wt%) and dimethyl ether are: 2650kg, 1860kg, 400kg, 4000kg and 1600kg, respectively.

C. Neutralization: after the reaction is completed, the pressure of the reactor is released, and the unreacted methyl chloride, ethylene oxide and dimethyl ether are vaporized and discharged into the separation device for separation and recovery. The remaining material is discharged from the reaction kettle, and then hydrochloric acid is added for neutralization, so that the pH value of the material is maintained between 6-8; The pH is 7±1.

D. Refining: After neutralization, add 8 times the mass of 90 ℃ hot water to the material for washing, then filter, rinse, steam filter through a continuous washing centrifugal filter, and finally pulverize and dry to obtain the finished cellulose mixed ether.

In step B, the alkalizing etherification efficiency of cellulose and methyl chloride, ethylene oxide and dimethyl ether are all affected by the stirring efficiency of the reactor, but the stirring paddle of the existing stirring Type, anchor type, frame type, propulsion type or straight blade turbine type, all only rotate around the paddle shaft, so the material flow inside the reactor has a certain rule, and there will not be more collisions between materials, so different The probability of contact and reaction between substances is also reduced, which in turn affects the efficiency of alkalization and etherification inside the reactor.

In order to improve the reaction efficiency of the reaction kettle, the reaction kettle is optimized in this embodiment.

The reaction kettle described in Step B of this embodiment includes a reaction kettle tank body 1 with an open upper end, a reaction kettle upper cover 2 and a stirring paddle provided above the reaction kettle tank body 1 .

The bottom of the reactor tank body 1 is provided with a discharge port, and the discharge port is provided with a valve. The reaction kettle is vertical, and the discharge port is directly below, which is conducive to discharging.

The inside of the reactor tank body 1 is provided with a heating pipeline, the oil heat conduction oil circulates inside the pipeline, and the pipeline is connected with an external heat conduction oil heating device, and the inside of the reactor tank body 1 is heated by the high temperature heat conduction oil. Alternatively, an electric heating sheet is added to the inner wall of the reaction kettle body 1, and the interior of the reaction kettle body 1 is heated by generating heat.

In order to further facilitate feeding, the reaction kettle body 1 is, from top to bottom, a cylindrical area, a circular table area 103 and a feeding pipe 101 which are arranged coaxially in sequence. Both the cylindrical area and the feeding pipe 101 are cylindrical. The vertical cross-sectional shape of the truncated truncated region 103 is a truncated truncated shape with the upper end diameter larger than the lower end diameter.

The opening of the lower end of the feeding pipe 101 is provided with a flap valve, and the flap valve includes a valve body 102 , a flap 7 and a first telescopic rod 701 . In the middle of the valve body 102 is a through hole with the same diameter as the feeding pipe 101 , a slot 1021 is recessed on the circumferential surface of the through hole, and half of the slot 1021 is connected to the outer wall of the valve body 102 through. The inserting plate 7 is inserted into the slot 1021 , and the end surface of the inserting plate 7 exposed to the outside of the valve body 102 is fixedly connected to the end of the telescopic portion of the first telescopic rod 701 . The first telescopic rod 701 is fixed on the outer wall of the valve body 102 .

The first telescopic rod 701 is an electric telescopic rod and adopts the prior art. The telescopic part is elongated, which drives the plug-in plate 7 to slide out of the slot 1021, and opens the through hole in the middle of the valve body 102, so that the material can be cut; The through hole in the middle of 102 is blocked.

A first feed pipe 201 , a second feed pipe 202 , a booster pipe 203 and a pressure relief pipe 204 are connected through the top of the upper cover 2 of the reactor.

The first feed pipe 201 is provided with a stop valve for adding powdered cellulose and lye under normal pressure;

The second feed pipe 202 is respectively connected with the methyl chloride supply pipeline, the ethylene oxide supply pipeline and the dimethyl ether supply pipeline through valves, and a check valve is connected in series on the second feed pipe 202, and the check valve ensures that only Materials can be added to the inside of the reactor through the second feed pipe 202;

The booster pipe 203 is connected with the nitrogen supply pipeline, and the booster pipe 203 is also provided with a one-way valve;

The pressure relief pipe 204 is connected through the separation device, and is also provided with a one-way valve.

The stirring paddle includes a vertical paddle shaft 3, which is coaxially arranged inside the reactor tank 1, and a paddle 301 is fixed on the paddle shaft 3, and the paddle 301 adopts a frame type or an anchor type. The upper end of the paddle shaft 3 is penetrated to the outside of the upper cover 2 of the reaction kettle and is fixed with a first bevel gear 302 .

The paddle shaft 3 is tubular, a central shaft 603 is coaxially penetrated inside the paddle shaft 3, an annular support plate 605 is sleeved on the circumferential surface of the central shaft 603, and the support plate 605 is located in the circular platform area 103, and the lower end of the paddle shaft 3 It is rotatably connected with the support plate 605 .

The central axis 603 is located on the circumferential surface below the support plate 605 and is wound with a spiral piece 6, the spiral piece 6 is inserted inside the feeding tube 101, the outer diameter of the spiral piece 6 is the same as the inner diameter of the feeding tube 101, that is, the outer wall of the spiral The inner wall of the feeding tube 101 is in contact. The height of the spiral plate 6 is higher than that of the feeding pipe 101 , that is, a part of the spiral plate 6 is located inside the circular truncated region 103 .

The upper end of the central shaft 603 is penetrated to the outside of the upper cover 2 of the reaction kettle, and a second bevel gear 604 is fixed.

A bottom shaft 601 is fixed at the lower end of the central shaft 603, a ring groove 602 is recessed on the circumferential surface of the bottom shaft 601, and a sleeve ring 1011 is rotatably sleeved inside the ring groove 602. They are fixedly connected by several fixing rods 1012. The distance between the bottom surface of the bottom shaft 601 and the plug board 7 is less than 1 cm.

A number of auxiliary stirring devices 4 are arranged in the interior of the reaction kettle body 1 and are distributed in an annular array around its axis.

The auxiliary stirring device 4 includes a rotating shaft 401 , a blade 402 and a first gear 403 . One end of the rotating shaft 401 is inserted into the paddle shaft 3 or the inner wall of the paddle 301 , and the other end is fixedly connected with the first gear 403 . Several blades 402 are fixedly connected with the circumferential surface of the rotating shaft 401, and the blades 402 can be stick-shaped, straight or curved.

The rotating shaft 401 is rotatably connected with the paddle shaft 3 or the paddle 301 .

The inner wall of the reaction kettle body 1 is provided with a gear ring 5 which is coaxially and fixedly connected. The rotating stirring paddle drives the rotating shaft 401 to rotate around the axis of the paddle shaft 3 , and then drives the first gear 403 to move along the ring gear 5 . Since the first gear 403 is meshed with the ring gear 5, the first gear 403 will roll and rotate on the ring gear 5, driving the blades 402 to rotate, and agitate the materials inside the reaction kettle. In this way, there are two devices with different rotation directions in the reaction kettle at the same time, so that the materials inside the reaction kettle will have collisions when flowing, thereby increasing the reaction efficiency.

In order to prevent the first gear 403 from jumping, a limit ring 501 is provided just above the ring gear 5. The limit ring 501 is fixedly connected to the inner wall of the reactor tank 1 by welding or bolting. The first gear 403 is located on the ring gear 5. 5 and the limit ring 501, the limit ring 501 blocks the first gear 403 from jumping up.

A first motor 8 and a driving mechanism are fixed on the upper cover 2 of the reaction kettle.

The driving mechanism includes a first transmission rod 9 , a second transmission rod 10 , a third transmission rod 11 , a fourth transmission rod 12 , a fifth transmission rod 13 and a regulating device 14 .

The first transmission rod 9 includes a third bevel gear 901 and a first pulley 902 that are coaxially and fixedly connected through a rotating rod;

The second transmission rod 10 includes a fourth bevel gear 1001, a second pulley 1002 and a third pulley 1003 that are coaxially and fixedly connected through a rotating rod;

The third transmission rod 11 includes a driven gear 1101, a fourth pulley 1102, a second gear 1103 and a third gear 1104 that are coaxially and fixedly connected by a rotating rod;

The fourth transmission rod 12 includes a fifth pulley 1201 and a fourth gear 1202 that are coaxially and fixedly connected through a rotating rod;

The fifth transmission rod 13 includes a sixth pulley 1301 and a fifth gear 1302 that are coaxially and fixedly connected through a rotating rod;

The regulating device 14 includes a vertically arranged second telescopic rod 1401 , a vertical rod 1402 , an upper roller 1403 and a lower roller 1404 . The second telescopic rod 1401 adopts the existing electric technology. The lower end of the vertical rod 1402 is fixedly connected with the top end of the telescopic part of the second telescopic rod 1401. The axis of the lower roller 1404 is arranged horizontally.

The third bevel gear 901 is meshed with the second bevel gear 604 , and the first pulley 902 and the fifth pulley 1201 are connected by the first timing belt 15 .

The fourth bevel gear 1001 is meshed with the first bevel gear 302 , the second pulley 1002 and the fourth pulley 1102 are connected by the second timing belt 16 , and the third pulley 1003 and the sixth pulley 1301 are connected by the third timing belt 17 .

The vertical rod 1402 is disposed between the second timing belt 16 and the third timing belt 17 , the upper roller 1403 is located directly above the second timing belt 16 , and the lower roller 1404 is located directly below the third timing belt 17 .

When the upper roller 1403 is not in contact with the second timing belt 16, the second timing belt 16 is in a relaxed state; when the lower roller 1404 is not in contact with the third timing belt 17, the third timing belt 17 is in a relaxed state.

The driven gear 1101 is meshed with the driving gear 801 on the output shaft of the first motor 8 , the second gear 1103 is meshed with the fifth gear 1302 , and the third gear 1104 is meshed with the fourth gear 1202 .

The first motor 8 drives the driving gear 801 to rotate. In order to control the speed of the driving gear 801 , the first motor 8 adopts a reduction motor, or a reduction box is added between the first motor 8 and the driving gear 801 .

The driving gear 801 drives the driven gear 1101 to rotate, then the third transmission rod 11 drives the fourth transmission rod 12 to rotate, and drives the second transmission rod 10 to rotate through the second synchronous belt 16 . The fourth transmission rod 12 drives the first transmission rod 9 to rotate through the first synchronous belt 15 . The first transmission rod 9 drives the screw blade 6 to rotate, and the second transmission rod 10 drives the paddle shaft 3 to rotate, thereby driving the rotation shaft 401 to rotate.

When the material inside the reactor is stirred, the rotation direction of the driving gear 801 does not change. At this time, the rotation direction of the spiral blade 6 makes the material move from the feeding pipe 101 to the circular table area 103, so the material will not flow into the insert plate. at the valve. At the same time, since a part of the helical blade 6 is located inside the round table area 103 and is in contact with the reacting material, it can also drive the material from bottom to top to play a certain stirring role.

Under the condition of keeping the rotation direction of the driving gear 801 unchanged, the elastic state of the second synchronous belt 16 and the third synchronous belt 17 is changed by controlling the expansion and contraction of the telescopic part of the second telescopic rod 1401 to adjust the tension of the second transmission rod 10 The rotation direction, and then realize the change of the forward and reverse rotation of the paddle shaft 3, and further improve the stirring efficiency inside the reaction kettle.

Since the second gear 1103 is meshed with the fifth gear 1302 , the rotation directions of the third transmission rod 11 and the fifth transmission rod 15 are opposite to each other.

When the telescopic part of the second telescopic rod 1401 moves down, the upper roller 1403 presses down the second timing belt 16, the lower roller 1404 moves away from the third timing belt 17, the second timing belt 16 is tightened, and the third timing belt is loosened, so that the third timing belt 16 is The transmission rod 11 drives the second transmission rod 10 to rotate, and drives the paddle shaft 3 to rotate in one direction; on the contrary, when the telescopic part of the second telescopic rod 1401 moves upward, the upper roller 1403 leaves the second synchronous belt 16, and the lower roller 1404 presses the third The timing belt 17 and the second timing belt 16 are slack, and the third timing belt is taut, so that the fifth transmission rod 13 drives the second transmission rod 10 to rotate, and drives the paddle shaft 3 to rotate in another direction. Therefore, the rotation direction of the paddle shaft 3 can be adjusted without changing the rotation direction of the first motor 8 by controlling the movement of the second telescopic rod 1401 .

When the material needs to be discharged, the second telescopic rod 1401 controls the upper roller 1403 and the lower roller 1404 not to contact the two conveyor belts, the first motor 8 is reversed, and the screw 6 drives the material to move under the lower feeding tube 101 and discharge. Since the inner wall of the circular truncated region 103 is an inclined plane, it is more favorable for cutting.

In step C, unreacted methyl chloride, ethylene oxide and dimethyl ether are separated and recovered by means of normal pressure condensation. To achieve this purpose, the present embodiment designs a separation device.

The separation device includes three liquefaction tanks, and the three liquefaction tanks are respectively used to liquefy ethylene oxide, methyl chloride and dimethyl ether. The boiling point of ethylene oxide under normal pressure is 10.8 ° C, and the boiling point of methyl chloride is -24.2 °C, the boiling point of dimethyl ether is -29.5 °C. Therefore, ethylene oxide is first separated by liquefaction, then methyl chloride is separated, and finally dimethyl ether is separated.

The liquefaction tank includes a first tank body 19, the inner cavity of the first tank body 19 is a rectangular parallelepiped, and the vertical cross-sectional shape of the first tank body 19 in the width direction is a square. The inner wall of the first box body 19 in the longitudinal direction is provided with a serpentine refrigeration pipe 23, and the inlet and outlet of the serpentine refrigeration pipe 23 are penetrated to the outside of the first box body 19 and are connected to the pipeline of the refrigeration unit.

The outside of the first box body 19 is provided with an air intake pipe 24 and an exhaust pipe 25 which are connected to its inner cavity. The bottom of the first box body 19 is recessed with a liquid drain groove 1903, and the bottom of the liquid drain groove 1903 is connected with a liquid drain pipe. 27. The end of the drain pipe 27 is penetrated to the outside of the first box body 19.

A valve is provided on the drain groove 1903 or the drain pipe 27 . In this embodiment, a lift valve 26 is provided inside the drain recess 1903 . The lift valve 26 descends to seal the through connection between the drain groove 1903 and the drain pipe 27 , and at the same time, the lift valve 26 is all located inside the drain groove 1903 .

In order to monitor the liquid level, a through cavity 1904 is provided inside the side wall of the first box body 19 and the air intake pipe 24 through connection. An electronic liquid level gauge 28 is arranged vertically.

The air inlet pipe 24 of the liquefaction tank for liquefying ethylene oxide is connected to the pressure relief pipe 204 of the reactor through; Connection; the exhaust pipe 25 of the liquefaction tank for liquefied methyl chloride is connected through the air inlet pipe 24 of the liquefaction tank for liquefied dimethyl ether; the exhaust pipe 25 of the liquefaction tank for liquefied dimethyl ether is connected through the nitrogen recovery pipeline.

The air inlet pipe 24 and the exhaust pipe 25 are connected to the side wall at one end of the first box body 19 in the longitudinal direction, that is, the through hole is located on the side wall at one end of the first box body 19 in the longitudinal direction. A through hole 1902 is provided on the side wall of the other end in the longitudinal direction of the first box body 19 .

The first box 19 is vertically provided with a piston 20. The end faces of the piston 20 are in contact with the inner wall of the first box 19. The piston 20 divides the inside of the first box 19 into two independent chambers.

At least two screws 21 are arranged inside the first box 19 along the length direction, the screws 21 pass through the piston 20, the screw 21 is threadedly connected with the piston 20, one end of the screw 21 is inserted into the inner wall of the first box 19, and the other end is penetrated A seventh pulley 2101 is fixedly connected to the outside of the first box body 19 .

A second motor 22 is fixed outside the first box 19 , and an eighth pulley 2201 is fixed on the output shaft of the second motor 22 .

In this embodiment, two screws 21 symmetrically arranged around the center of the piston 20 are used, and the second motor 22 drives the two screws 21 to rotate at the same time, so that the two screws 21 are synchronized, so as to avoid jamming during the movement of the piston 20 .

In order to further improve the smoothness of the movement of the piston 20 , a horizontally arranged guide rod 1901 is fixed between the two sides in the length direction of the first box 19 .

In order to improve the sealing performance, a sliding seal is provided between the piston 20 and the guide rod 1901 .

One end of the piston 20 facing the through hole 1902 is fixed with a rubber sleeve 2001 , and the rubber sleeve 2001 is threadedly connected to the screw rod 21 . The rubber sleeve 2001 has elasticity, so it can be in close contact with the screw 21 to improve the sealing performance.

A pressure sensor is set on the inner wall of the first box 19 which is throughly connected with the intake pipe 24 and the exhaust pipe 25 . When gas enters the inside of the first box 19 and the pressure increases, the piston 20 moves in the direction of the through hole 1902 to increase the space and reduce the internal pressure; when part of the gas liquefies and the pressure decreases, the piston 20 moves in the direction of the intake pipe 24, Reduce space and increase internal pressure.

An air box 29 is provided outside the liquefaction tank. The air box 29 includes a second box body 2901 with an open upper end. An elastic gasket 2902 is covered at the opening above the second box body 2901. The elastic gasket 2902 passes through the fixing frame. 2903 is fixedly connected to the second box 2901.

A test tube 2904 is penetratingly connected to the outside of the second box body 2901 . The test tube 2904 is provided with a stop valve. The through hole 1902 is connected to the second box body 2901 through the connecting air passage 30 . The gas in the air box 29 is used for the movement of the piston 20 , and the elastic gasket 2902 is used to elastically change the inner space of the second box 2901 to cooperate with the movement of the piston 20 .

The increase of the air box 29 makes the piston 20 in the three first boxes 19 connected to the through hole 1902 to form a closed space, so that even if ethylene oxide, methyl chloride and dimethyl ether leak through the piston 20, will also flow only within this space.

Then, the test tube 2904 can be pumped for inspection periodically, and the content of ethylene oxide, methyl chloride and dimethyl ether in this space can be inspected to judge the airtightness of the piston 20. The inspection method is the prior art. It is also possible to supply air to the inside of the air box 29 through the test tube 2904 .

The refrigeration unit is in the prior art, and this embodiment adopts the refrigeration unit with the same principle as the air conditioner, that is, includes a motor, a compressor, related pipelines, and an internal refrigerant.

The system composed of the reaction kettle and the separation device also includes a nitrogen tank 31, an intermediate tank 32, a storage tank 33 and an electric control box. The electric control box adopts the existing technology, including a control device and a power module. The control device adopts PLC or has an industrial control chip. The integrated circuit, all the electrical devices in the whole system are electrically connected with the electric control box.

The outlet of the nitrogen tank 31 is connected with the booster pipe 203 of the reactor through the nitrogen gas inlet pipe 01. The nitrogen gas inlet pipe 01 is connected with a booster pump and a stop valve in series, and high-pressure nitrogen is injected into the reactor, which plays a protective role and reacts The air inside the kettle is blown clean, and the pressure inside the reactor can also be increased to achieve the effect of supercharging.

The air inlet pipe 24 of the liquefaction tank for liquefying ethylene oxide is connected with the pressure relief pipe 204 of the reactor through the connecting gas pipe 03; the exhaust pipe 25 of the liquefaction tank for liquefying ethylene oxide is connected with the The air inlet pipe 24 is connected through the connecting air pipe 03; the exhaust pipe 25 of the liquefaction tank of liquefied methyl chloride and the air inlet pipe 24 of the liquefaction tank of liquefied dimethyl ether are connected through the connection air pipe 03; the exhaust of the liquefaction tank of liquefied dimethyl ether The pipe 25 and the nitrogen tank 31 are connected through the nitrogen gas return pipe 02 .

The drain pipes 27 of the three liquefaction tanks are all connected through the first liquid collecting pipe 04 to the individual intermediate tank 32 , and the intermediate tank 32 is connected through the single storage tank 33 through the second liquid collecting pipe 05 . The first liquid collection pipe 04 and the second liquid collection pipe 05 are connected in series with a pressurizing pump and a stop valve.

The three storage tanks 33 are respectively used to store high-pressure liquefied ethylene oxide, methyl chloride and dimethyl ether.

The three storage tanks 33 are respectively connected to the first feeding pipe 201 through the first liquid feeding pipe 06, the second liquid feeding pipe 07 and the third liquid feeding pipe 08. The first liquid feeding pipe 06 and the second liquid feeding pipe 07 And the third liquid inlet pipe 08 is connected with a pressure pump and a stop valve in series.

The connecting gas pipe 03 and the nitrogen gas return pipe 02 can be connected in series with an air pump and a shut-off valve, and the gas in the former container can be pumped into the latter container through the air pump.

Another form of gas transfer can also be achieved. That is, after the alkalization and etherification is completed, the pressure relief pipe 204 is opened first to reduce the pressure inside the reactor, so that ethylene oxide, methyl chloride and dimethyl ether are vaporized. Then, normal pressure nitrogen was injected into the reactor, ethylene oxide, methyl chloride and dimethyl ether in the reactor were blown out through a pressure relief pipe, and blown into the liquefaction tank for liquefying ethylene oxide.

The refrigeration unit reduces the internal temperature of the liquefaction tank for liquefying ethylene oxide to between -20°C and 10°C, and moves the piston 20 to adjust the air pressure inside the space where the mixed gas is located, so that it maintains about normal pressure, so that its internal mixer The ethylene oxide in the ethylene oxide begins to liquefy. During the liquefaction process, the internal air pressure decreases. At this time, the internal pressure is maintained by adjusting the position of the piston 20 .

After the refrigeration time reaches the threshold, or the height of the electronic liquid level gauge does not change, and the detection data of the pressure sensor does not change, the lift valve 26 is opened, and the liquefied ethylene oxide is pressurized and pumped into the intermediate tank 32. , high-pressure liquefied ethylene oxide is stored in the intermediate tank 32 , and when the ethylene oxide storage amount in the intermediate tank 32 reaches a threshold value, it is pumped into the ethylene oxide storage tank 33 .

When the liquefied ethylene oxide is exhausted, move the piston 20 to the direction of the exhaust pipe 25 to push out the gas left in the first box 19, and push it into the liquefied methyl chloride through the connecting gas pipe 3. inside the liquefaction tank. The refrigeration unit reduces the temperature inside the liquefaction tank for liquefying methyl chloride to between -28°C and -25°C, liquefies the methyl chloride in the mixed gas, and pumps it into a separate intermediate pipe after liquefaction. After all the liquid is discharged, the piston 20 is moved to push the remaining gas into the liquefaction tank for liquefying dimethyl ether.

The refrigeration unit lowers the temperature inside the liquefaction tank for liquefying the dimethyl ether to below -30° C., liquefies and separates the dimethyl ether in the mixed gas, and pumps it into the separate intermediate tank 32 .

Then, when the piston 20 is moved, the remaining nitrogen gas is pushed into the nitrogen gas tank 31 and reused. The gas components inside the nitrogen tank 31 are sampled regularly to detect the contents of ethylene oxide, methyl chloride and dimethyl ether inside.

Since the boiling point of ethylene oxide is 10.8 °C, the boiling point of methyl chloride is -24.2 °C, and the boiling point of dimethyl ether is -29.5 °C, the boiling point of ethylene oxide is more than 30 degrees higher than that of methyl chloride and dimethyl ether, so in order to save energy , in this embodiment, as shown in FIG. 2, there are two common refrigeration units 34, which respectively refrigerate the liquefaction tanks of methyl chloride and dimethyl ether, while the two width directions of the liquefaction tanks of ethylene oxide are opposite to each other. A serpentine refrigerating pipe 23 is respectively arranged inside the side wall, and the outlet of the serpentine refrigerating pipe of the methyl chloride and dimethyl ether liquefaction tank is respectively connected to the inlet of the two serpentine refrigerating pipes 23 inside the ethylene oxide liquefaction tank. The refrigerant first cools the liquefaction tank of methyl chloride and dimethyl ether, and then uses the residual temperature to adjust the temperature in the ethylene oxide liquefaction tank inside the serpentine refrigeration pipe 23 flowing into the ethylene oxide liquefaction tank.

That is, the two common refrigeration units 34 inject liquid refrigerant into the serpentine refrigeration pipe 23 inside the liquefaction tank of methyl chloride and dimethyl ether respectively through a cryostat refrigerant supply pipe 006, and the refrigerant reduces the amount of refrigerant in the methyl chloride and dimethyl ether liquefaction tank. The temperature inside the first box 19 is then discharged through a cryogenic box refrigerant discharge pipe 001, and discharged into the serpentine refrigeration pipe 23 of the ethylene oxide liquefaction tank to adjust the temperature inside the ethylene oxide liquefaction tank, Then the refrigerant is returned to the inside of the common refrigeration unit 34 through the common unit refrigerant return pipe 005 to perform refrigeration and start the next cycle.

But sometimes, after the refrigerant cools the methyl chloride liquefaction tank or the dimethyl ether liquefaction tank or the chloromethane and dimethyl ether liquefaction tank, the temperature of the refrigerant is too high, and it cannot continue to cool the ethylene oxide liquefaction tank. In this case, in order to maintain the temperature of the ethylene oxide liquefaction tank, a backup refrigeration unit 35 is added in this embodiment. At the same time, the relevant connecting pipelines have been optimized.

At this time, a temperature sensor 36 is provided on the refrigerant discharge pipe 001 of the low temperature box to detect the temperature of the refrigerant inside the refrigerant discharge pipe 001 of the low temperature box. The three joints of the three-way valve 37 are respectively connected to the low temperature box refrigerant discharge pipe 001 , the refrigerant reuse pipe 002 , and the low temperature box refrigerant bypass discharge pipe 007 .

The end of the refrigerant reuse pipe 002 is connected to the high temperature tank refrigerant inlet pipe 003 and the high temperature tank backup refrigerant supply pipe 009 through an electronically controlled three-way valve.

The end of the refrigerant bypass discharge pipe 007 of the low temperature box is connected to the refrigerant return pipe 005 of the common unit through a valve.

The outlets of the two serpentine refrigeration pipes 23 in the ethylene oxide liquefaction tank are connected through the high temperature tank refrigerant discharge pipe 004, and the end of the high temperature tank refrigerant discharge pipe 004 is connected to the common unit refrigerant return pipe 005 and the high temperature tank refrigerant through an electronically controlled three-way valve. The main return line 0012 is connected.

The high temperature tank refrigerant main return pipe 0012 and the high temperature tank backup refrigerant supply pipe 009 are respectively connected to the refrigerant inlet and outlet of the backup refrigeration unit 35 through.

When the temperature sensor 36 detects that the temperature of the refrigerant inside the refrigerant discharge pipe 001 of the low temperature box is higher than the threshold value and cannot reduce the temperature inside the ethylene oxide liquefaction tank to below 10.8°C, the corresponding electronically controlled three-way valve 37 will adjust the flow of the refrigerant. path. At this time, the refrigerant inside the low temperature box refrigerant discharge pipe 001 flows into the low temperature box refrigerant bypass discharge pipe 007 through the electronically controlled three-way valve, and then flows into the common unit refrigerant return pipe 005, and finally enters the common refrigeration unit 34. Cool down. The standby refrigeration unit 35 is started, and the low temperature refrigerant inside it flows into the high temperature tank refrigerant inlet pipe 003 through the high temperature tank standby refrigerant supply pipe 009 and the electronically controlled three-way valve, and then flows into the serpentine refrigeration of the ethylene oxide liquefaction tank. Inside the pipe 23, the inside of the ethylene oxide liquefaction tank is cooled. The refrigerant after heat exchange is returned to the standby refrigeration unit 35 through the high temperature box refrigerant discharge pipe 004, the electronically controlled three-way valve, and the high temperature box refrigerant main return pipe 0012, and the temperature is re-cooled.

The standby refrigeration unit 35 can not only provide refrigeration for the ethylene oxide liquefaction tank, but also serve as a standby unit to replace any common refrigeration unit 34 when one of the two common refrigeration units 34 is shut down due to failure. Add some necessary piping for this.

That is, the refrigerant outlet of the standby refrigeration unit 35 is connected to the standby unit refrigerant discharge pipe 008, and the end of the standby unit refrigerant discharge pipe 008 is connected to the high temperature tank standby refrigerant supply pipe 009 and the low temperature tank standby refrigerant supply manifold 0014 through an electronically controlled three-way valve.

The cold box standby refrigerant supply main pipe 0014 is respectively connected with two low temperature tank standby refrigerant supply branch pipes 0015 through two valves, and the two low temperature tank standby refrigerant supply branch pipes 0015 respectively deliver low temperature refrigerant to the liquefaction tank of methyl chloride and dimethyl ether.

The end of the cold box standby refrigerant supply branch pipe 0015 is connected to the low temperature box refrigerant supply pipe 006 through a valve, and the low temperature box standby refrigerant supply branch pipe 0015 is connected in parallel with the common refrigeration unit 34 .

The refrigerant inlet of the standby refrigeration unit 35 is throughly connected to the standby unit refrigerant return pipe 0013, and the other end of the standby unit refrigerant return pipe 0013 is connected to the high temperature tank refrigerant return pipe 0012 and the low temperature tank standby refrigerant return pipe 0016 through an electronically controlled three-way valve.

The other end of the cold box standby refrigerant return pipe 0016 is connected to the low temperature box refrigerant bypass discharge pipe 007 and the common unit refrigerant return pipe 005 through an electronically controlled three-way valve.

When a common refrigeration unit 34 fails, the flow path of the refrigerant becomes: standby refrigeration unit 35 - standby unit refrigerant discharge pipe 008 - low temperature box standby refrigerant supply main pipe 0014 - low temperature box standby refrigerant supply branch pipe 0015 - low temperature box refrigerant Supply pipe 006-dimethyl ether liquefaction tank or methyl chloride liquefaction tank-low temperature box refrigerant discharge pipe 001, low temperature box refrigerant bypass discharge pipe 007-low temperature box standby refrigerant return pipe 0016-standby unit refrigerant return pipe 0013-standby refrigeration unit 35 ;

Or, standby refrigeration unit 35 - standby unit refrigerant discharge pipe 008 - low temperature box standby refrigerant supply main pipe 0014 - low temperature box standby refrigerant supply branch pipe 0015 - low temperature box refrigerant supply pipe 006 - dimethyl ether liquefaction tank or methyl chloride liquefaction tank - low temperature box Refrigerant discharge pipe 001 - refrigerant reuse pipe 002 - ethylene oxide liquefaction tank - high temperature tank refrigerant discharge pipe 004 - high temperature tank refrigerant return pipe 0012 - standby unit refrigerant return pipe 0013 - standby refrigeration unit 35.

Since the two serpentine refrigeration pipes 23 inside the ethylene oxide liquefaction tank are independent, it is convenient to be connected to a common refrigeration unit 34 respectively, but it is unfavorable to connect to a spare refrigeration unit 35 . In order to allow the refrigerant to pass through the two serpentine refrigeration pipes 23 when the practical standby refrigeration unit 35 refrigerates the ethylene oxide liquefaction tank alone, in this embodiment, electricity is passed between the two refrigerant inlet pipes 003 of the high temperature tank. The control three-way valve is connected to a high temperature tank backup refrigerant supply branch pipe, and the high temperature tank standby refrigerant return branch pipe 0011 is connected between the two high temperature tank refrigerant discharge pipes 004 through an electronically controlled three-way valve. By adjusting the valve core position of the electronically controlled three-way valve, the backup refrigerant supply branch pipe of the warm box and the backup refrigerant return branch pipe 0011 of the high temperature box, the two serpentine refrigeration pipes 23 inside the ethylene oxide liquefaction tank are connected into a whole, so that the backup refrigeration The unit 35 can inject refrigerant into the two serpentine refrigeration pipes 23 at the same time.

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and can also be made within the scope of knowledge possessed by those of ordinary skill in the art without departing from the purpose of the present invention. Various changes.

Claims (10)

1. cellulose mixed ether gas-solid production technology, is characterized in that, comprises the following steps: A. Pulverization: pulverize cotton pulp or wood pulp to obtain powdery cellulose with a particle size of 200-230 μm and a bulk density of 180-200 g/L; B. Alkalization and etherification: add powdery cellulose and lye into the reaction kettle, then inject high-pressure nitrogen into the reaction kettle for boosting, the pressure rises to 2.3MPa, and then add high-pressure liquid methyl chloride and ethylene oxide With dimethyl ether, the temperature is uniformly heated to 40-70 ℃, and the basification etherification reaction is carried out; C, neutralization: after the reaction finishes, the pressure relief is carried out to the reactor, and the unreacted methyl chloride, ethylene oxide and dimethyl ether are vaporized and discharged into the separation device for separation and recovery; the remaining materials are discharged from the reactor , and then add hydrochloric acid for neutralization, so that the pH value of the material is maintained between 6-8; D. Refining: After neutralization, add water to the material for washing, then filter, rinse, steam filter through a continuous washing centrifugal filter, and finally pulverize and dry to obtain the finished cellulose mixed ether. 2. cellulose mixed ether gas-solid production technology according to claim 1, is characterized in that: The reaction kettle described in step B comprises a reaction kettle tank body (1) with an open upper end, a reaction kettle upper cover (2) and a stirring paddle provided above the reaction kettle tank body (1), The bottom of the reactor tank body (1) is provided with a discharge port, and the discharge port is provided with a valve, A first feeding pipe (201), a second feeding pipe (202), a pressure boosting pipe (203) and a pressure relief pipe (204) are connected through the top of the upper cover (2) of the reaction kettle, The first feed pipe (201) is provided with a stop valve, The second feed pipe (202) is respectively connected with the methyl chloride supply pipeline, the ethylene oxide supply pipeline and the dimethyl ether supply pipeline through a valve, The booster pipe (203) is connected to the nitrogen supply pipeline, The pressure relief pipe (204) is connected through the separation device, The stirring paddle comprises a paddle shaft (3), the paddle shaft (3) is coaxially arranged inside the reactor tank body (1), a paddle (301) is fixed on the paddle shaft (3), and the upper end of the paddle shaft (3) is penetrated to the A first bevel gear (302) is fixed outside the upper cover (2) of the reaction kettle, A first motor (8) is fixed on the upper cover (2) of the reaction kettle, and the first motor (8) drives the first star-chasing gear (302) to rotate. 3. cellulose mixed ether gas-solid production technology according to claim 2, is characterized in that: The reaction kettle body (1) is sequentially arranged from top to bottom in a coaxially arranged cylindrical area, a circular table area (103) and a feeding pipe (101). The inner diameter of the feeding tube (101) is the same as the inner diameter of the lower end of the circular truncated area (103), and the inner diameter of the cylindrical area is the same as the inner diameter of the upper end of the circular truncated area (103). The opening of the lower end of the feeding pipe (101) is provided with a flapper valve, The paddle shaft (3) is tubular, a central shaft (603) is coaxially penetrated inside the paddle shaft (3), and an annular support plate (605) is sleeved on the circumferential surface of the central shaft (603). (605) is located in the round table area (103), and the lower end of the paddle shaft (3) is rotatably connected with the support plate (605), The central shaft (603) is located on the circumferential surface below the support plate (605) and is wound with a spiral piece (6), the spiral piece (6) is inserted inside the feeding tube (101), and the outer diameter of the spiral piece (6) is the same as that of the feeding tube (101). The inner diameter of the pipe (101) is the same, The upper end of the central shaft (603) is penetrated to the outside of the upper cover (2) of the reaction kettle, and a second bevel gear (604) is fixed, The output shaft of the first motor (8) drives the second bevel gear (604) to rotate. 4. cellulose mixed ether gas-solid production technology according to claim 3, is characterized in that: A bottom shaft (601) is fixed at the lower end of the central shaft (603), a ring groove (602) is recessed on the circumferential surface of the bottom shaft (601), and a sleeve ring (1011) is rotatably sleeved inside the ring groove (602), A plurality of fixing rods (1012) are fixedly connected between the circumferential surface of the collar (1011) and the inner wall of the feeding pipe (101). 5. cellulose mixed ether gas-solid method production technology according to claim 2 or 3 or 4, is characterized in that: The inner wall of the reaction kettle body (1) is provided with a toothed ring (5), A number of auxiliary stirring devices (4) distributed in an annular array around the axis of the reaction kettle body (1) are provided inside, The auxiliary stirring device (4) comprises a rotating shaft (401), a blade (402) and a first gear (403). One end of the rotating shaft (401) is inserted into the inner wall of the paddle shaft (3) or the paddle (301), and the other end is connected to the first gear (403). A gear (403) is fixedly connected, Several blades (402) are fixedly connected with the circumferential surface of the rotating shaft (401), The rotating shaft (401) is rotatably connected with the paddle shaft (3) or the paddle (301), the first gear (403) is arranged on the gear ring (5), and the first gear (403) is meshed with the gear ring (5). 6. cellulose mixed ether gas-solid production technology according to claim 5, is characterized in that: A drive mechanism is provided above the upper cover (2) of the reaction kettle, The driving mechanism comprises a first transmission rod (9), a second transmission rod (10), a third transmission rod (11), a fourth transmission rod (12), a fifth transmission rod (13) and a regulating device (14), The first transmission rod (9) includes a third bevel gear (901) and a first pulley (902) that are coaxially and fixedly connected through a rotating rod, The second transmission rod (10) includes a fourth bevel gear (1001), a second pulley (1002) and a third pulley (1003) that are coaxially and fixedly connected through a rotating rod, The third transmission rod (11) includes a driven gear (1101), a fourth pulley (1102), a second gear (1103) and a third gear (1104) that are coaxially and fixedly connected by a rotating rod, The fourth transmission rod (12) includes a fifth pulley (1201) and a fourth gear (1202) that are coaxially and fixedly connected through a rotating rod, The fifth transmission rod (13) includes a sixth pulley (1301) and a fifth gear (1302) that are coaxially and fixedly connected through a rotating rod, The regulating device (14) comprises a vertically arranged second telescopic rod (1401), a vertical rod (1402), an upper roller (1403) and a lower roller (1404), and the lower end of the vertical rod (1402) is telescopic with the second telescopic rod (1401) The tops of the upper rollers (1403) and the lower rollers (1404) are respectively arranged up and down on both sides of the vertical rod (1402), and the axes of the upper rollers (1403) and the lower rollers (1404) are arranged horizontally, The third bevel gear (901) is meshed with the second bevel gear (604), the first pulley (902) is connected with the fifth pulley (1201) through the first timing belt (15), The fourth bevel gear (1001) is meshed with the first bevel gear (302), the second pulley (1002) is connected with the fourth pulley (1102) through the second timing belt (16), and the third pulley (1003) is connected with the The sixth pulley (1301) is connected by the third timing belt (17), The vertical rod (1402) is arranged between the second timing belt (16) and the third timing belt (17), the upper roller (1403) is located just above the second timing belt (16), and the lower roller (1404) is located at the third timing belt (1404) Just below the belt (17), When the upper roller (1403) is not in contact with the second timing belt (16), the second timing belt (16) is in a relaxed state, When the lower roller (1404) is not in contact with the third timing belt (17), the third timing belt (17) is in a relaxed state, The driven gear (1101) is in meshing connection with the driving gear (801) on the output shaft of the first motor (8), the second gear (1103) is in meshing connection with the fifth gear (1302), and the third gear (1104) is in meshing connection with the fourth gear (1104). Gears (1202) are meshed. 7. cellulose mixed ether gas-solid production technology according to claim 1 or 6, is characterized in that: The separation device includes three liquefaction tanks, and the three liquefaction tanks are respectively used for liquefying ethylene oxide, methyl chloride and dimethyl ether, The liquefaction tank comprises a first box body (19), the inner cavity of the first box body (19) is a cuboid, and a serpentine refrigeration pipe (23) is arranged in the inner wall of the first box body (19) in the length direction, and the snake The inlet and outlet of the refrigerating pipe (23) are penetrated to the outside of the first box body (19), and are connected to the pipeline of the refrigeration unit. The outside of the first box body (19) is provided with an air intake pipe (24) and an exhaust pipe (25) which are throughly connected to its inner cavity, and a drainage groove (1903) is recessed in the bottom of the first box body (19) for drainage A drain pipe (27) is connected through the bottom of the groove (1903), and the end of the drain pipe (27) is penetrated to the outside of the first box (19), There is a valve on the drain groove (1903) or the drain pipe (27), The air inlet pipe (24) of the liquefaction tank for liquefying ethylene oxide is connected through the pressure relief pipe (204) of the reactor, The exhaust pipe (25) of the liquefaction tank for liquefying ethylene oxide is connected through the air inlet pipe (24) of the liquefaction tank for liquefying methyl chloride, The exhaust pipe (25) of the liquefaction tank of liquefied methyl chloride is connected through the air inlet pipe (24) of the liquefaction tank of liquefied dimethyl ether, The exhaust pipe (25) of the liquefaction tank for liquefying the dimethyl ether is connected through the nitrogen recovery pipeline. 8. cellulose mixed ether gas-solid production technology according to claim 7, is characterized in that: A piston (20) is vertically arranged inside the first box body (19), and the surrounding end faces of the piston (20) are in contact with the inner wall of the first box body (19), At least two screws (21) are arranged inside the first box body (19) along the length direction, the screws (21) pass through the piston (20), the screw (21) is threadedly connected with the piston (20), and one end of the screw (21) is inserted into the piston (20). It is arranged in the inner wall of the first box body (19), the other end is penetrated to the outside of the first box body (19) and is fixedly connected with a seventh pulley (2101), A second motor (22) is fixed outside the first box body (19), an eighth pulley (2201) is fixed on the output shaft of the second motor (22), and the eighth pulley (2201) passes through all the seventh pulleys (2101). The same fourth timing belt (2202) is connected. 9. cellulose mixed ether gas-solid production technology according to claim 8, is characterized in that: The air intake pipe (24) and the exhaust pipe (25) are connected to the side wall of one end of the first box body (19) in the longitudinal direction, A through hole (1902) is provided on the side wall of the other end in the length direction of the first box body (19), One end of the piston (20) facing the through hole (1902) is fixed with a rubber sleeve (2001), and the rubber sleeve (2001) is threadedly connected with the screw rod (21). 10. cellulose mixed ether gas-solid production technology according to claim 9, is characterized in that: An air box (29) is provided outside the liquefaction tank, and the air box (29) includes a second box body (2901) with an open upper end, The upper opening of the second box body (2901) is covered with an elastic sealing gasket (2902), and the elastic sealing gasket (2902) is fixedly connected to the second box body (2901) through the fixing frame (2903), A test tube (2904) is connected through the outside of the second box (2901), and a stop valve is provided on the test tube (2904). The through hole (1902) is connected to the second box body (2901) through the connecting air passage (30).

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