WO2008004407A1 - Method of pulverization drying and pulverization drying apparatus - Google Patents

Abstract

[PROBLEMS] To provide a method of performing appropriate pulverization drying, etc. of raw material, etc. with the use of a pulse combustor, and provide an apparatus for use in the method. [MEANS FOR SOLVING PROBLEMS] Pulverization drying apparatus (10) includes pulse combustor (pulse engine) (1) and, disposed in the vicinity of exit of exhaust pipe (1b) thereof, material inputting pipe (2). The pulse combustor (1) generates in the vicinity of exit thereof a pulse combustion jet of 60 to 1000 Hz frequency, 140 to 180 dB sound pressure and 50° to 600°C temperature, into which droplets containing a material as processing object are fedthroughthe material inputting pipe (2).

Description

 Specification

 Crushing and drying method and crushing and drying apparatus

 Technical field

 [0001] The claimed invention is based on the use of food, medicine, chemical industrial products, etc. as raw materials, supplying them together with droplets, pulverizing, dehydrating and drying, and applying this technology to water-based emulsions. The present invention relates to a pulverizing and drying method and a pulverizing and drying apparatus for the purpose of using John or the like for coating film formation with a low moisture content.

 Background art

 [0002] The following Patent Document 1 and the like show that various raw materials can be dehydrated and dried using a Nord combustor (pulse engine). Patent Document 2 describes that a raw material in the form of a solution or slurry can be pulverized and dried by supplying it in the vicinity of the outlet of the exhaust pipe of the pulse combustor.

[0003] As shown in Fig. 1, the Norse combustor includes a combustion chamber la and an exhaust pipe lb, and functions as follows. First, air (primary air) and fuel are supplied to the combustion chamber la from the supply pipe lc 'Id, respectively, and at startup, the mixture in the combustion chamber la is ignited by a spark plug (not shown) (explosion combustion process) . The combustion gas rises in pressure due to combustion and is ejected from the exhaust pipe lb at a high speed, and continues to be ejected by the action of inertia after the end of combustion (expansion and exhaust stroke). Air and fuel are again sucked into the combustion chamber la that has become negative pressure due to the injection of combustion gas, and the high-temperature combustion gas in the exhaust pipe lb also flows back into the combustion chamber la (intake Mixing process). When the temperature of the combustionless combustor 1 rises as the operation continues and the temperature of the combustion gas becomes sufficiently high, the air-fuel mixture in the combustion chamber la will self-ignite due to the backflowing combustion gas, and the Norus combustion Even if the spark plug le is not used, the device 1 continues so-called pulse combustion that repeats explosions several hundreds to several hundreds per second. As a result of such combustion, a pulse combustion jet with a high-energy nonlinear wave is emitted near the outlet of the Norm combustor, so if the raw material (substance to be dried) is supplied in the form of a solution, the raw material is While being pulverized by the action of the jet, it causes solid-liquid separation and dries in a short time. Patent Document 1: Japanese Patent Publication No. 6-33939

 Patent Document 2: Japanese Patent Laid-Open No. 2006-90571

[0004] Including the description of each of the above-mentioned patent documents, the state of the Norse combustion jet and the supply mode of the solution and the like for appropriately pulverizing and drying the solution and the raw material have not been clarified so far. . For example, it was not clear how much wave energy was given to the combustion jet to crush and dry the solution. In addition, even if it is known that the raw material can be dried in a short period of time, an inappropriate chemical change (thermal denaturation) can be performed to determine how much the raw material can be affected by the temperature of the nozzle combustion jet. There is no possibility of waking up, and! /, The points are well understood! /, And! /, I couldn't.

 Disclosure of the invention

 Problems to be solved by the invention

[0005] In view of the above points, the claimed invention intends to provide a method for appropriately pulverizing and drying raw materials using a Knoll combustor, and an apparatus used for the method. It is.

 Means for solving the problem

[0006] The pulverization drying method of the claimed invention is a method of pulverizing droplets containing a raw material to be treated (subject to be pulverized and dried) and drying the raw material, and the pulse combustor uses an outlet thereof. In the vicinity (near the outlet of the exhaust pipe. For example, a location in front of the opening end that is the outlet and about 10 mm away from the opening end)

 Frequency is 60Hz or more · 1000Hz or less,

 Sound pressure is 140dB or more · 180dB or less,

 Temperature is 50 ° C or higher · 600 ° F or lower

 This is characterized in that the above-mentioned nozzle combustion jet (combustion exhaust with non-linear wave) is formed, and the droplets are supplied into the pulse combustion jet.

[0007] As with a normal burner, a normal combustor can generate a linear wave corresponding to a sound wave and burn it (non-null combustion) by adjusting the amount of fuel and air supplied, etc. It is possible to burn (pulse combustion) while generating non-linear waves (pulse shock waves) with strong! / Impact. Since the vibrations associated with the combustion of the nozzle involve high sound pressure, By this wave, the raw material is dispersed into fine particles, and at the same time, the air boundary layer on the surface is destroyed and moisture near the surface is stripped off, so that the material is instantly dried. The pulverization and drying method of the invention controls the fuel supply amount, air supply amount (combustion air or cooling air amount), raw material input amount, or raw material input state when the no-less combustor performs no-less combustion. As described above, a pulse combustion jet having a wave of 60 to 1000 Hz, 140 to 180 dB and a temperature of 50 to 600 ° C. is ejected as described above, and droplets are supplied into the jet. These nozzle combustion jets have high wave energy, while their thermal energy is relatively small and low temperature (in contrast to the highest temperature above 700 ° C when burning non-north like a burner). Is). Therefore, in this method, the droplets containing the raw material can be appropriately pulverized and dried, and the thermal effect on the raw material is suppressed. Therefore, there is an advantage that drying in an extremely short time is realized, and the temperature of the raw material is not increased so much that heat denaturation such as scorching, deterioration, or alteration does not easily occur.

[0008] In the pulverization drying method of the invention, in particular, the frequency is 700Hz or more · 800Hz or less near the outlet by a Nos combustor,

 Sound pressure is 140dB or more · 160dB or less,

 Temperature is over 50 ° C · 350 ° Ο or less

 The nozzle combustion jet is formed, and the droplet is put into the nozzle combustion jet.

 Diameter of about 3mm or less (eg;! ~ 3mm)

 It is preferable to supply it!

 The inventors conducted experiments under these conditions, and as a result, confirmed that the droplets were properly crushed and dried. Because the temperature of the combustion jet is quite low, it is possible to produce dry fine powder at temperatures below 60 ° C, for example, unless the time for the droplet to stay in the jet is particularly long. There is no chemical change such as scorching, deterioration, or alteration.

 [0009] It is advantageous that the supply point of the droplet is in front of the outlet of the pulse combustor and is between the outlet and a distance that is three times (preferably 1.5 times) the inner diameter of the outlet. is there.

According to the experiments by the inventors, when a Norse combustor burns by emitting a Norse shock wave, it is a range where the vibration is strong and accompanied by a strong oscillating vortex (thus, a range where the action of crushing droplets is strong). ) Is limited to a limited area of up to about 3 times the exit diameter. For this reason, supplying droplets from the outlet of the pulse combustor to a distance three times the outlet diameter as described above is advantageous in terms of efficient pulverization and drying.

[0010] In the above pulverization drying method, in particular, the outlet of the nozzle combustor may face the resonance chamber (resonance tube), and the droplets may be supplied inside the resonance chamber.

 By facing the outlet of the Norm combustor into the resonance chamber, a standing wave of a pulse shock wave can be formed in the resonance chamber. If droplets are supplied inside such a resonance chamber, the droplets are exposed to nonlinear waves for a long time and are strongly dispersed and dried, and can be efficiently crushed and dried. . Even when eddy currents occur around particles

, The action is particularly remarkable. In addition, since the frequency is 1000 Hz or less, it is advantageous in that strong wave energy can exist in the resonance chamber for a long time.

 [0011] In addition, the supply of the droplets described above is as follows: a) the impact of the Norse combustion jet is received several times (preferably 5 times or more) while the droplets move near the outlet of the pulse combustor; and b) No chemical changes (burnt, deterioration, alteration, etc.) occur in the above raw materials

 It is good to be fi.

 In other words, the droplet force S pulse combustion jet is in the droplet force S pulse combustion jet for a sufficient time to satisfy the above a), and the droplet force S pulse combustion jet exits within a short time enough to satisfy the above b). To do. In order to increase the residence time of the droplets in the Norse combustion jet, the force to reduce the droplet movement speed, the diameter of the combustion jet (the diameter of the outlet of the pulse combustor), etc. are increased. Conversely, in order to shorten the staying time, the force for increasing the moving speed of the droplet, the diameter of the combustion jet, etc. are reduced. For example, if the droplet movement speed is 3 m / s, the nozzle combustion jet diameter is 30 mm, and the jet frequency is 700 Hz, the droplet stays in the jet for a maximum of about 0.01 second, and the same time. The impact of the jet is about 7 times.

In our experiments, droplets are not necessarily crushed by a single impact from a pulse combustion jet. However, if the impact is applied multiple times as described above, each droplet is crushed and dried with a high probability. As illustrated above, if a droplet stays in the jet for about 0.01 seconds and receives the impact of the jet about seven times during that time, the droplet is almost certainly crushed and dried effectively. The jet temperature is 50 At ~ 350 ° C, it is very unlikely that the droplet will undergo chemical changes within the residence time of about 0.01 seconds.

 [0012] As an application of the above pulverization drying method, the outlet of the pulse combustor (the destination of the pulse combustion jet) is directed to the coating film forming surface, and droplets that are coating material are supplied into the pulse combustion jet. It is also preferable to do.

 This is because meaningful coating can be formed on the coating surface. In other words, the above-described pulverization and drying action allows the coating material supplied as droplets to reduce moisture and finely disperse and adhere to the coating surface, thereby enabling preferable coating on the same surface. It is. Film materials such as resin emulsion and resin dispersion have a solid content of 20 to 30% from the viewpoint of storage stability of the solution. Therefore, when coating is performed using a blade coater, etc., a sufficiently thick film is formed. In order to achieve this, it is necessary to apply 2 to 3 coats while drying each time. However, according to the above method, since the water content of the coating material is instantaneously reduced to a solid content concentration that allows thick coating, the coating material is applied once, or a few times. It is possible to obtain the desired film thickness by applying coating. Since the coating film is formed after the water content is reduced, the subsequent drying can be performed in a very short time. As described above, the reduction of the moisture content in the coating material is performed instantaneously, at low temperatures, and at a low temperature. Therefore, there is very little possibility that the material will be altered. Also, according to the above method, the droplets of the same material are dispersed finely, so there is an effect that it is homogeneous and beautiful, and when a coating film is formed.

[0013] It is more preferable to supply an inert gas around the no-les combustion jet.

 In the Norm combustor, the air in the combustion gas or around the combustion gas is used to cool the combustor itself and control the temperature, and to transport moisture separated from the raw material by drying. (Secondary air) may be sprayed. Instead of such secondary air, an inert gas is supplied. Then, the chemical change of the raw material in the pulse combustion jet is further suppressed by the action of the inert gas.

[0014] It is particularly preferable to supply hydrogen as a fuel for the no-les combustor.

When the fuel is hydrogen, it is preferable from the viewpoint of environmental protection because it only generates water by combustion. In addition, it is difficult to cause an inappropriate reaction with raw materials. It is preferable to suppress the chemical change of!

[0015] It is also preferable to supply the organic solvent as the droplets containing the raw material to be treated. As organic solvents, low-boiling point methanol, ethanol, acetone, ethyl acetate, etc. can be handled in high quantities. In particular, the organic solvent supplied as droplets should be pulverized and evaporated without being burned by a nozzle combustion jet.

 When supplying organic solvent droplets, if the pulse combustor performs non-no-burn combustion like a burner, the solvent will burn due to the high-temperature flame. When forming a less combustion jet! /, You can crush and evaporate the droplets without burning them. In this way, the organic solvent in the droplets can be recovered, and the thermal effect on the raw material in the droplets can be suppressed to avoid scorching, deterioration, or alteration. it can.

 Therefore, the outlet of the pulse combustor is directed to the coating surface, and the organic combustion IJ is placed in a Norse combustion jet (for example, frequency 700 to 800 Hz, sound pressure 140 to 160 dB, temperature 50 to 350 C). If both supply droplets containing a coating material, the coating material can be finely dispersed and adhered to the coating film forming surface while reducing the solvent content. A coating having a sufficient thickness can be formed by spraying once or a few times, and a uniform and beautiful coating can be formed. Therefore, a preferable coating can be formed on a surface of cloth, paper, metal or the like.

[0016] When the organic solvent is evaporated as described above, the organic solvent is separated from the adsorbent and recovered by adsorbing the evaporated organic solvent on the adsorbent (activated carbon or the like) and then heating the adsorbent. Is also good!

 Since the evaporated organic solvent has not undergone chemical changes due to combustion, it can be collected by adsorbing it directly onto an adsorbent such as activated carbon. If the adsorbed adsorbent is then heated, the organic solvent is separated and removed, and can be recovered and reused. In this way, consumption of organic solvents and release into the atmosphere can be reduced.

[0017] A pulverizing and drying apparatus according to a claim includes a Norse combustor and a droplet supply device, and is configured to perform any one of the pulverizing and drying methods. is there. With such a pulverizing and drying apparatus, the above pulverizing and drying methods can be carried out to bring about preferred effects and effects.

 Brief Description of Drawings

 FIG. 1 shows an embodiment of the present invention, and is a conceptual diagram showing a main part of a pulverizing and drying apparatus 10 including a nos combustor 1 and a raw material inlet 2.

 FIG. 2 is an overall schematic diagram of a pulverization drying apparatus 10 constituted by a drying tower 11 including a pulse combustor 1 and other related equipment.

 FIG. 3 is a schematic longitudinal sectional view showing a web-like substrate coating apparatus 20.

 FIG. 4 is a system diagram showing an apparatus for recovering the pulverized and evaporated organic solvent.

 FIG. 5 is a conceptual diagram showing a no-les combustor and measurement equipment used in the experiment.

 [Fig. 6] A diagram showing the results of measurement of the jet pressure spectrum during pulse combustion (Fig. 6 (a)) and non-nozzle combustion (Fig. 6 (b)) in a pulse combustor. is there.

 [Fig. 7] Changes in pressure (Fig. 7 (a)) and temperature (Fig. 7 (b)) measured at each point along the radial (diameter) direction at the nozzle outlet position of the nozzleless combustor. FIG.

 FIG. 8 is a diagram showing measurement results of pressure (FIG. 8 (a)) and temperature (FIG. 8 (b)) measured at a position along the central axis of the nozzle outlet of the pulse combustor.

 [Fig. 9] Fig. 9 (;!) To (6) are series photographs showing images of the behavior of a droplet when the droplet is freely dropped into a nozzle combustion jet.

 [FIG. 10] FIGS. 10 (;!) To (4) are series photographs showing images of the behavior of droplets when droplets (ethanol) are supplied into the Norse combustion jet.

 Explanation of symbols

[0019] 1-no-less combustor

 la combustion chamber

 lb exhaust pipe

 2 Raw material input tube (droplet feeder)

 10 Crushing and drying equipment

 20 Coating equipment

BEST MODE FOR CARRYING OUT THE INVENTION [0020] FIGS. 1 to 10 show an embodiment of the invention. Fig. 1 is a conceptual diagram showing the main parts of a crushing and drying device 10 including a no-les combustor 1 and a raw material input pipe 2. Fig. 2 shows a drying tower (crushing and drying chamber) 11 including a pulse combustor 1 and others. 1 is an overall schematic diagram of a crushing and drying apparatus 10 constituted by the related equipment. FIG. 3 is a schematic longitudinal sectional view showing a coating apparatus 20 for a web-like substrate, and FIG. 4 is a system diagram showing an apparatus for recovering an organic solvent which has been pulverized and evaporated. 5 to 10 are diagrams showing the equipment used in the experiment described later and the experimental results.

 The pulverization / drying apparatus 10 is configured as shown in FIG. The drying tower 11 is composed of a Norls combustor 1 provided inside and a pulverization drying chamber 13 provided in connection therewith. The connection between the Norm combustor 1 and the grinding / drying chamber 13 is as shown in Fig. 1, and the partition wall of the grinding / drying chamber 13 is connected to the outlet of the exhaust pipe lb connected to the combustion chamber la of the pulse combustor 1. . A raw material inlet pipe (droplet feeder) 2 is provided immediately downstream of the outlet of the exhaust pipe lb, and a slurry or solution raw material is supplied into the pulverizing and drying chamber 13 from this. As shown in FIG. 2, the crushing and drying chamber 13 has a lower hopper connected to a bag filter 15, and exhaust air is sucked and discharged by a blower 16. The above raw materials are sent out by the pump 14 and supplied as droplets from the inlet 2 into the crushing and drying chamber 13. The powder particles produced by crushing and drying the droplets by the action of the no-les combustor 1 fall to the bottom of the crushing and drying chamber 13 and are collected by the bag filter 15 and then collected in the collection container 15a. To be recovered.

 [0022] The Norm combustor (pulse engine) 1 is configured as shown in Fig. 1. In order to cause pulse combustion, an air (primary air) supply pipe lc and a fuel supply pipe Id are externally provided. Connected. As fuel, gas fuel such as city gas' propane 'propylene' hydrogen or liquid fuel such as kerosene 'light oil' heavy oil can be used. In the Norm combustor 1, a secondary air supply pipe Π is connected around the exhaust pipe lb. The secondary air is supplied for the purpose of cooling the Norm combustor 1 to control the temperature of the crushing and drying chamber 13 and carrying out the water separated from the raw material by drying. An inert gas such as nitrogen or argon can be supplied together with or in place of the secondary air.

[0023] Also, in the Norm combustor 1 of FIG. 1, the supply amount of the air (primary air) supply pipe lc, the fuel supply pipe ld, the secondary air supply pipe Π, and the raw material input pipe 2 are adjusted. Equipment (flow Quantity adjustment valve. (Not shown) is provided. For the raw material input tube 2, it is possible to change the raw material input mode, that is, the droplet size and the supply speed! When each supply amount or raw material charging mode is adjusted manually or with a control device, each adjusting device functions as a gas adjusting means! / In other words, the particle Reino number of exhaust gas near the raw material input pipe 2 The temperature and the primary particle size of the input raw material can be appropriately changed. By operating the adjusting device's! / And the displacement force to change the number of particles in the gas, the wave energy (frequency. Sound pressure) and thermal energy (temperature) of the pulse combustion jet in the crushing and drying chamber 13 are changed. Etc. can be appropriately changed. Further, a standing wave can be generated in the chamber 13 depending on the relationship between the frequency of the wave and the size of the grinding / drying chamber 13. A pressure sensor (for example, a semiconductor pressure sensor) 3 is further attached to the side of the combustion chamber la in the Nore combustor 1 (the part reaching the exhaust pipe lb) for wave detection.

 [0024] In the pulverization / drying apparatus 10 shown in Fig. 1 and Fig. 2, by setting the above-mentioned adjusting device appropriately, a non-linear wave (pulse shock wave) having a strong impact is generated in the pulverization / drying chamber 13 to be stationary. Let When a droplet of a raw material (a droplet containing food, chemicals, chemical industrial products, etc. as a raw material) is introduced into the pulse combustion jet with such non-linear wave by the above-mentioned injection tube 2, it is 1 / It is possible to effectively pulverize and dry the raw material within a short time of about 100 seconds or less. This is because the droplets are reduced in size by the impact action, and a vortex is generated around the droplets taken into the standing wave flow field of the nonlinear wave, and the water around the droplets is removed as vapor. In the pulverization / drying chamber 13, the room temperature has risen to, for example, about 60 ° C. due to the heat generated by the pulse combustor 1, and the secondary air transports moisture out of the system. Promoted.

FIG. 3 is a schematic view showing a coating apparatus 20 for a web-like substrate (cloth * paper * metal band, etc.) to which the principle of pulverization and drying as described above is applied. The web-shaped substrate X is spread and unrolled by the unwinding machine 21 and the winding machine 22 and a plurality of rollers 23 arranged between them, and the nozzle combustor 1 with the outlet facing the surface of the substrate X. Is attached. A resin emulsion or resin dispersion as a coating material can be supplied as droplets in the vicinity of the outlet of the combustor 1 by the supply means 2a and the input pipe 2 subsequent thereto. Further, a heating dryer for finally drying the substrate X between the charging pipe 2 and the winder 22 is used. 24 are arranged.

 [0026] When a droplet of the coating material is supplied from the charging tube 2 while operating the no-les combustor 1 and burning it, the droplet is subjected to moisture by the action of a pulse combustion jet with non-linear waves. The amount is instantaneously reduced and thickly adheres to the surface of the substrate X with a high solid content. The solid content concentration of the coating material in the supply means 2a and the charging tube 2 is usually 20-30%. When the moisture content is reduced with a combustion jet, the solid content concentration becomes a gel-like material with a solid content concentration of 70-90%. . Therefore, even if the base material X is not permeable, such as metal, and the coating material is water-based, the required coating thickness is almost once on the surface of the base material X. Or a few times). Since the moisture content of the coating material is reduced, the drying time after each application is also greatly reduced. According to the coating apparatus 20, the substrate X can be efficiently coated in this way.

 [0027] It is also possible to coat the base material X with a coating material together with an organic solvent using the coating apparatus 20 shown in FIG. That is, if the droplets of the coating material (dissolved in an organic solvent) are supplied from the inlet tube 2 to the vicinity of the outlet of the combustor 1 while being burned by the nozzle combustor 1, the action of the pulse combustion jet The organic solvent in the droplets is pulverized and evaporated instantaneously without burning, so that the coating material with a high solid content is deposited on the surface of the substrate X in a thicker thickness. This also makes it possible to carry out a preferred coating on the substrate X.

[0028] When supplying droplets of an organic solvent into a nozzleless combustion jet, the solvent can be recovered by a recovery device configured as shown in FIG. The apparatus shown in Fig. 4 has an exhaust gas pipe 31 from a crushing and drying apparatus (reference numeral 10 in Figs. 1 and 2) connected in parallel with adsorbers 32Α and 32Β containing activated carbon. The outlets of the adsorbers 32Α and 32Β are connected to the air discharge pipe 33, thereby discharging clean air into the atmosphere. In addition, a heater is attached to each of the adsorbers 32Α and 32Β, a water supply 34 is connected to the inlet side, a recovery pipe 35 is connected to the outlet side, and the solvent is recovered by the condenser 36 and separator 37. Alternatively, the solvent is processed by the electric furnace 38. By properly opening and closing the valves placed before and after the adsorbers 32Α and 32Β, one adsorber 32 adsorbs the organic solvent contained in the exhaust gas from the pulverization dryer to activated carbon, and the other adsorber 32 And heating the activated carbon By supplying water to the water, the adsorbed organic solvent is separated and recovered. By alternately switching between the two adsorbers 32, the adsorption and recovery of the solvent can be performed simultaneously in succession.

 Example

 [0029] The inventors conducted experiments on the behavior of droplets near the outlet of the pulse combustor, etc., and made various measurements and observations in order to establish a pulverization drying technique using a Norse shock wave. The procedure and results are shown below.

<Experimental apparatus and method>

 The no-les combustor used in the experiment has the shape of a Helmholtz resonator as shown in Fig. 5.

テールパイプ (ノズル。排気管）の出口での直径は, The volume of the combustor 3.25 X 10- ⁵

The diameter at the exit of the tail pipe (nozzle, exhaust pipe) is

29mm.

 In this experiment, Nols combustion was performed using the parameters shown in Table 1, and changes in pressure and temperature in the radial and axial directions of the injection jet were measured downstream of the nozzle outlet. At the time of measurement, the Norse combustor was fixed at the theoretical amount of air that produced the most stable combustion (air ratio: 1.2), and a combustion gas swirl jet was generated by changing the amount of combustion.

 Next, as shown in Fig. 5, a high-speed video camera and a shutter are used to show how droplets with a diameter of 2 to 3 mm fall freely in this oscillating combustion gas jet and the droplets collapse in the oscillating gas jet. It was visualized by a dough graph optical device and examined in detail. Shooting with a high-speed video camera was performed at 5,000 frames / second. The pressure was measured using a semiconductor pressure sensor, and the temperature was measured using a thermocouple. The spectrum of pressure fluctuations of the vibrating jet was obtained using an FFT frequency analyzer. The following liquid droplets were used. 1) water, 2) water + sand sugar + tarry me powder, 3) water + salt + resin powder (particle size 300) + PE pellet (diameter lmm, length 3mm), 4) water + salt + PVP (viscosity Solution) + resin powder (particle size 300, 500) + PE pellet (diameter lmm, length 3mm), 5) polymer solution, 6) candle solution.

[0031] [Table 1] Combustion soot LPG flow rate AIR flow rate Air ratio

13.6 MJ / h 0.15 m ³ / h 4.5 m ³ / h 1.2

10.0 MJ / h 0.11 m ³ / h 3.3 m ³ / h 1.2

[0032] <Experimental results and discussion>

 1) Pressure and temperature measurement

 In order to investigate the basic characteristics of the combustion gas jet, we measured the jet pressure spectrum during pulse combustion and non-north combustion (burner combustion). An example of the obtained spectrum is shown in Fig. 6. Fig. 6 (a) shows the spectrum during pulse combustion, and Fig. 6 (b) shows the spectrum during non-north combustion (burner combustion)!

 From Fig. 6 (a), it can be seen that the Norse combustion jet vibrates violently at a frequency of about 700 Hz.

[0033] 2) Pressure / temperature measurement (radial direction)

 Figures 7 (a) and 7 (b) show the changes in pressure (sound pressure) and temperature measured in the radial direction (diameter) at positions 10 mm and 60 mm downstream of the nozzle outlet of the Nors combustor. “LPG_0.15” indicates the case where the nozzle combustion is performed, and “LPG-0.11” indicates the case where the burner combustion is performed (non-NORS combustion). (10) and (60) shown in parentheses indicate the distance from the nozzle outlet.

 From these figures, the average pressure near the central axis of the jet is about 25 dB higher during pulse combustion (LPG-0.15) than the burner combustion (LPG-0.11). It can be seen that the temperature is getting lower.

[0034] 3) Pressure / temperature measurement (axial direction)

Figures 8 (a) and 8 (b) show the measurement results of pressure and temperature measured in the direction of the central axis of the nozzle of the nozzle combustor. In these figures, X on the horizontal axis indicates the distance from the nozzle outlet, and D indicates the inner diameter of the nozzle (29 mm) at the nozzle outlet. The dark color plot shows the pressure and temperature during pulse combustion (LPG-0.15), thin! /, And the color plot shows the pressure and temperature during burner combustion (LPG-0.11)! /. From these figures, the average pressure at the same position on the shaft is about 25 dB higher in the burner combustion than in the burner combustion, and the average temperature in the pulse combustion is higher in the pulse combustion. It can be seen that the temperature is about 800 ° C lower. In addition, from Fig. 8 (aHb), during pulse combustion (LPG-0.15), the rate of change slows down from the vicinity of 45mm (X / D = 1.5) from the temperature force S and the combustor outlet! /, Therefore, it is strong within the range from the combustor outlet to this distance!

 4) Visualized image

 Analyzing the images taken at 5,000 frames / second, the behavior of the droplets when the droplets with a diameter of 2 to 3 mm were freely dropped toward the pulse combustion gas jet and the burner combustion gas jet were examined. .

 During burner combustion, large turbulent vortices with a diameter on the order of lcm are observed throughout the jet, and are observed to move downstream along with the jet S. Vortices were distributed throughout the jet and were seen to move downstream with the pulsating jet.

 When a droplet is dropped onto a burner combustion jet, the droplet gradually evaporates from its surface, passes through the jet without dramatic deformation, and appears below the jet. It was observed that droplets with a diameter of 2-3 mm were completely broken in the jet. Figure 9 (;!) To (6) series photographs show how a droplet (water droplet) with a diameter of about 2 mm is destroyed in a “Norse combustion pulsating gas” jet. The time elapses in numerical order, and the time interval between each image is about 4 ms. In these photographs, at the moment of (1), a spherical droplet (black dot above the center of the photograph) passes through the boundary of the pulse jet. At the moment of (2) and (3), the original droplet is deformed into a sheet shape by the impact with the contact surface that moves downstream after the shock wave in the pulse combustion jet, and (4) to (6 At the moment of), it was observed that it was atomized by persistent contact with the surface and then evaporated completely in a gas jet at 100-300 ° C. From this image, it can be seen that the water droplets collapsed in a short time of 20 msec (dozens of impacts). Moreover, a phenomenon was observed in which the water droplet diameter after the collapse fluctuated by changing the density difference of the oscillating vortex and the water droplet diameter.

In an experiment in which a droplet containing a slightly larger PE pellet with a diameter of lmm 'and a length of 3mm, or a droplet of PVP (viscous solution) added to water was dropped into a Nols combustion jet, it was refined and rearward Moisture that is blown to the (downstream side) and PE pallet or sticky that falls to the nearer position The phenomenon of segregation with the preferential substance was observed.

[0036] <Conclusion>

 In this experiment, basic research was conducted to investigate the possibility of fine particle production technology using pulse combustion jets. In these experiments, we conducted detailed experiments to investigate the phenomenon of droplet breakage in a visualization experiment using a high-speed video camera, and also performed numerical analysis. As a result, the following was found.

 (1) The pressure in the pulse combustion jet is about 25 dB higher than the pressure in the non-pulse combustion jet, and the average temperature is about 800 ° C lower.

 (2) A large number of large turbulent vortices with a diameter of 1 cm appear in a non-north combustion (burner combustion) jet and move downstream with the jet.

 (3) An infinite number of small turbulent vortices on the order of lmm in diameter appear in the Norse combustion jet and move downstream with the vibrating jet.

 (4) In non-pulsed combustion jets, droplets with a diameter of 2 to 3 mm gradually evaporate from the surface while passing through the burner combustion jet, and pass through the jet without dramatic deformation.

 (5) In a pulse combustion jet, a droplet with a diameter of 2 to 3 mm is deformed into a sheet by several impacts with the contact surface that moves downstream after the shock wave in the jet, and then continues It forms a mist on impact with the contact surface and evaporates completely in a 100-300 ° C gas-jet.

 (6) In an experiment using a liquid in which solid particles were dispersed, the liquid was removed by the mechanism shown in (5) above in the Norse combustion jet, and the solid particles could be completely separated.

 (7) The gas around the fine particles is a flow with vortices that are extremely effective for droplet breakup, and the time required for evaporative drying is the relative flow of gas around the particles, `` Particle Reynolds It is expected to depend strongly on the “number (Re number)”.

 [0037] <Others>

Experiments were also performed in the same manner as described above in the case where droplets of an organic solvent (ethanol) were supplied into a no-les combustion jet instead of water droplets. In the experiment, the same pulse combustor and measuring equipment as shown in Fig. 5 were used. No-les combustion in a no-les combustor, and ethanol droplets with a diameter of 2 to 3 mm are supplied from the supply pipe into the combustion gas jet to visualize the behavior of the droplets. And shot at 5,000 frames / second with a high-speed video camera.

 A series of photographs (1) to (4) in Figure 10 shows how the droplet (ethanol) is destroyed. The time elapses in numerical order, and the time interval between each image is about 4 ms. From these photographs, it is observed that the droplets are pulverized and atomized almost at the same time as they leave the supply tube, and evaporate without burning.

Industrial applicability

 It is industrially advantageous to dry the raw material using a Noles combustor.

Claims

The scope of the claims  [I] A method of pulverizing droplets containing a raw material to be processed and drying the raw material,  Nores combustor ί and therefore near the exit ί, 60 ~; 1000Hz * 140 ~; 180dB * 50 ~ 600 ° C forms a no-les combustion jet, and the above droplets in the no-les combustion jet A pulverizing and drying method, characterized in that  [2] Noless combustor ί and therefore near its outlet ί, 700 ~ 800Hz * 140 ~; 160dB * 50 ~ 350 2. The pulverizing and drying method according to claim 1, wherein a nozzle combustion jet at ° C is formed, and the droplets are supplied into the nozzle combustion jet with a diameter of about 3 mm or less.  [3] The pulverization drying according to claim 1 or 2, characterized in that the droplets are supplied in front of the outlet of the pulse combustor and between the outlet and a distance three times the inner diameter of the outlet. Method.  [4] The pulverization drying method according to any one of claims 1 to 3, wherein the outlet of the nore combustor faces the resonance chamber, and the droplets are supplied inside the resonance chamber. [5] A feature of the invention is that the droplet is subjected to a plurality of impacts by a pulse combustion jet while moving in the vicinity of the outlet of the pulse combustor, and supplied so that no chemical change occurs in the raw material. Item 5. A method for crushing and drying according to any one of Items 1 to 4. [6] The droplet combustor material according to any one of claims 1 to 5, wherein the outlet of the nozzle combustor is directed to the coating film forming surface, and droplets as coating material are supplied into the nozzleless combustion jet. The pulverization drying method described in 1.  [7] The inert gas is supplied around the no-les combustion jet. V, the grinding and drying method according to any one of the above. [8] The pulverization drying method according to any one of [1] to [7], wherein the fuel of the nore combustor is hydrogen.  [9] The pulverization drying method according to any one of claims 1 to 8, wherein the organic solvent is supplied as the droplets containing the raw material to be treated. 10. The pulverizing and drying method according to claim 9, wherein the organic solvent supplied as droplets is pulverized and evaporated without being burned by a nozzle combustion jet. [II] By adsorbing the evaporated organic solvent to the adsorbent, and then heating the adsorbent 11. The pulverization drying method according to claim 10, wherein the organic solvent is separated from the adsorbent and recovered.  A pulverizing and drying apparatus comprising a pulse combustor and a droplet feeder, wherein the pulverizing and drying method according to any one of claims 1 to 11 is implemented.