SU1750598A1 - Device for roasting tea leaves - Google Patents

Abstract

The invention m. Is used in the primary processing of green tea leaves and lao-cha in tea factories. The device for roasting the tea leaf comprises a heat-insulated jacket with two drums mounted one above the other for rotation by a drive. The drums have feed augers, as well as a heat generator for heating and a fan. The shafts of the loading augers are made hollow, and the heat-insulated casing has a channel for communication of its upper part with the cavity of the lower drum through the fan and the hollow shaft of the loading auger. The heat generator is made in the form of gas burners of infrared radiation. The burners are evenly installed under the bottom drum along its entire length with the possibility of adjusting the distance to the drum surface. The charging augers are rigidly connected to the drums with the help of adapter screws. Conveyors for feeding and draining tea leaves are kinematically connected to the drums in the same vertical plane. 1 hp ff, 5 ill. sl C

Description

The invention relates to the food industry and can be used in primary tea processing factories in the production of green tea and lao cha.

The purpose of the invention is to improve the quality of the target product, the reliability and thermal efficiency of the device.

To achieve this goal, in a device for roasting the tea leaf, which includes a heat-insulated casing with two drums, mounted one above the other rotatably by means of an actuator and having loading augers, conveyors for feeding and discharging the tea leaf, the heat generator for

heating the drums and the fan, the shafts of the loading screws of the drums are hollow, the heat-insulated casing has a channel for communicating its upper part with the cavity of the lower drum through the fan and the hollow shaft of the loading auger, and the heat generator is made in the form of infrared gas burners evenly installed under the lower drum throughout its length with the possibility of adjusting the distance to its surface,

In addition, to simplify the design, the feed screws are rigidly connected to the drums using transition screws, and conveyors for feeding and draining

about you

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tea leaves are kinematically associated with drums in the same vertical plane.

Figure 1 shows the proposed device, figure 2 - section aa in figure 1; in FIG. 3, node I in FIG. Fig, 4-section BB in Fig.1; figure 5 is a section bb In figure 1.

The device for roasting the tea sheet contains a supporting frame 1, a heat-insulated casing 2 fixed to it, mounted in the casing 1 of the primary processing drum 3 and below it the secondary processing drum 4. Drums 3 and 4 have internal double-winding spiral windings 5 and 6, respectively. The lower end of the drum 4 is supported on the frame 1 by means of two bands 7 mounted on the drum and four roller supports 8. The upper drum 3 is supported on the band 7 of the lower drum 4 by means of bands 9 mounted on drum 3 and on frame 1 using four roller supports 10 located in the horizontal axial section of the drum 3. At the inlet of the upper drum 3 in the lower semi-cylindrical part of the loading nozzle 11 there is a loading screw 12 fixed on the drum 3 by means of a transition screw 13. The screws 12 and 13 have a common hollow shaft 59. At the ba output Habana 3 cover 14 is arranged in the lower semi-cylindrical portion which is mounted coaxially with the drum 4 the loading screw 15, rigidly mounted on the drum 4 by the transition of the screw 16. The common shaft 17 of the screws 15 and 16 is hollow. The coils of the screws 12 and 13 and the spiral winding 5 are double-threaded and are a continuation of each other. The coils of the screws 15 and 16 and the spiral winding 6 are also two-threaded and are a continuation of each other. In the lower part of the heat-insulated housing 2 under the bottom drum 4 there is a heat generator containing a series of infrared gas burners 18 (Asterisk. Operating instructions K 6204-FOORE, 1982), gas fittings 19 for adjustable gas supply to the burners 18, gas burners movement mechanism 20 for adjusting the distance between their heating elements and the outer surface of the lower drum 4, the actuator 21 of the mechanism 20. For access of air to the burners 18 in the lower part of the device, there are swivel shutters 22. For inspection the heat generator and the repair work, the heat-insulated housing 2 in the lower part has opening 24 around the hinges 23 of the door 24, the inner cavity of the housing 2 on the upper side is connected to the air inlet of the fan 25 through the tunnels 26 and the filter 27 of the heat agent for precipitating the microparticles and moisture formed from combustion gas. At the bottom of the filtering unit 27 there is a pipe 28 for collecting and removing microparticles and moisture precipitated from the thermal agent, and at the top a pipe 29 for sucking atmospheric air with a valve 30 for controlling the amount of intake air. At the fan 25 there is a valve 31 - to regulate the amount of the mixture of air and thermal agent. The outlet of the fan 25 is connected with the internal cavity of the shaft 17 through the pipe 32. Drums 3

5 and 4 are kinematically connected to each other by means of a pair of gear wheels 33 and 34, rigidly mounted on the upper and lower drums 3 and 4, respectively. The drive gear 35 of the drum 4 is kinematically connected with the gear wheel 34 and located on the same shaft 36 with the driven pulley 37 of the belt transmission from the electric motor 38. The belt pulley in the belt transmission serves as the drive pulley 39 on the rotor shaft of the ventilator 25. In the inlet section of the hollow shaft 17 there is a diaphragm 40 with peripheral sector-like openings 41 for the passage of the heat agent and a central conic they hole 42 for attachment axis L of the guide 43 naprav0 conical nozzle 44 and the counterweight 45. The diaphragm 40, the axis 43, a guide tapered nozzle 44 and counterweight 45 form a unit deflection teploagenta stream fed to the thick frying

5 masses of tea leaf to increase the efficiency of its drying after passing the upper drum 3. The plant is equipped with conveyors 46 and 47, respectively, for feeding and draining the tea leaf. Conveyor

0 46 has a hopper 48 for loading the tea leaf and a cross-shaped rotating spreading sheet 49 of the tea leaf with the possibility of adjusting the distance from the grader to the carrier belt of the porter. The blades 50 are fixed to the carrier tape of the conveyor 46 to lift the tea leaf. 51 of the conveyor 46 is rigidly mounted gear 53, which is kinematically connected

0 with a gear wheel 33 by means of a gear 54. Gear 57 is rigidly mounted on the shaft 55 of the driving drum 56, which meshes with the gear wheel 34. The device also contains a nipple 58

5 to remove water vapor heat transfer fluid from the device.

The device for roasting the tea leaf works as follows.

The motor 38 is switched on. By means of a belt transmission from

the driven slag motor 37 begins to rotate the drive pulley 39 of the fan 25 and the drive gear 35. The drive gear 35 transmits the rotation to the drums 4 and 3 using a pair of gear wheels 34 and 33. Another pair of gear wheels 34 and 33 drives the conveyor 47 to drain the tea through the gears 34 and 57, and the conveyor 46 for feeding the tea leaf through the gears 33, 54 and 53. The cruciform spreading device 49 is rotated by a chain drive (not shown) from the shaft 52 of the driving drum 51 of the conveyor 46. The lower drum 4 wrestling Spiral winding 5 fixed on it, shakes 12 and 13 rotate on four roller supports 8 by means of bands 7. Upper drum 3, spiral windings 6 rigidly fixed on it, screws 15 and 16 with hollow shaft 17 rotate on bands 7 of lower drum 4 by means of tires 9 and four rollers 10. As a result of the rotation of the hollow shaft 17, the axis 43 rolls inside the conical hole 42 of the diaphragm 40, and the counterweight 45 on the lower inner surface of the hollow shaft 17, the guide cone 44 rotating around its own axis and not changes the position in space, In such an arrangement, the tapered nozzle 44 always overlaps the upper portion of the outlet of the hollow shaft 17 and directs the flow of gases coming from the fan 25 to the inner surfaces of the lower drum 4, preferably to the lower surfaces.

A semiautomatic electric igniter (not shown) is then switched on and, through gas fittings 19, provides a regulated supply of gaseous fuel — natural or liquefied gas to the burners 18. The electric ignitor provides the start of gas combustion and is turned off. The required amount of air is accessed by the burners 18 through the rotary shutters 22. Before or after switching on the burners 18 from the manual actuator 21, the mechanism 20 controls the distance between the heating elements of the burners 18 and the outer surface of the lower drum 4 and sets the burners 18 to the desired position. The shutter 30 is adjusted on the nozzle 29 for suction of atmospheric air, the shutter 31 and set them in the desired position. The infrared rays produced by burning the gas in the infrared burners 18 reach the rotating drum 4 and heat it. Heat agents (products of combustion) formed in the process of gas combustion, flow

the surface of the lower roasting drum 4, then flows around the surface of the upper roasting drum 3. Next, the heat agent through the tunnels 26 enters the filter-5 air conditioner 27, where microparticles and moisture are precipitated, which are then removed through the drain (pipe) 28. In the filter air conditioner 27 the heat agent is mixed with atmospheric air coming from

0 pipe 29, and is directed to the fan 25, by means of which it is injected into the hollow shaft 17 through the fixed pipe 32. From the hollow shaft 17 through the holes 41 of the diaphragm 40 by means of a conical

5 of nozzle 44, the mixture of heat agent and air is directed to the inner walls of drum 4, mainly to the lower walls, moves along the axis of drum 4 and is removed through nozzle 58 to the atmosphere or sent for another purpose, for example, to dry twisted tea leaf.

After a certain time (about 5–7 mm) of operation of the device, sufficient for

5, heating the working surfaces to the required temperature, start loading the tea leaf into the hopper 48, where the tea leaf is grasped by the vanes 50 of the conveyor 46 in a uniform layer by means of the rotating leveler 49 and rises up. When bending around the carrier belt of the conveyor 46 around the leading drum 51 of the conveyor 46, the tea leaf is poured down into the semi-cylindrical nozzle 11c.

5 bottom, where it is captured by the turns of the two-feed screw 12 and is fed into the upper primary processing drum 3 via the dual-feed transition screw 13. In the primary processing drum 3 tea leaves

0 is agitated and moved along the axis of the drum 3 by means of two-winding spiral winding 5. As the tea leaf is stirred and moved in the drum 3, a gradual warming up occurs

5 tea leaves under the influence of the high temperature of the heated inner wall of the drum 3 and the spiral winding 5, resulting in the destruction and inactivation of the enzyme systems of the leaf, in

0 mainly orthodiphenol oxidase and peroxidase, in connection with which the tea leaf in the upper drum 3 partially loses its ability to ferment. In addition, due to the gradual warming up of the cell membranes

5 sheets, i.e. hemicellulose and cellulose, the coarse, dense and rather fragile tea leaf gradually becomes soft and elastic. During the initial processing (primary roasting) of the tea leaf in the upper drum 3, some of the water is evaporated from the leaf. The water-based water vapor is mostly left inside the upper drum 3 and facilitates heat treatment of the subsequent flow of the sheet. The remaining 3 of the vapors formed in the drum are removed from the drum 3 through the hollow shaft 59. Partially brewed tea leaves are discharged from the upper drum 3 and poured into the lower semi-cylindrical part the lid 14, where it is gripped by a two-feed screw 15 and fed into the lower drum 4 of the secondary treatment through a two-way transfer screw 16. When the tea leaf is moved and stirred by two Khodnev spiral winding used in tea leaves drum 4 is exposed to the preheated drum interior sten- ki, s teploagenta also coming from the hollow shaft 17, causing the tea leaf intensely and uniformly grew hot. Under the influence of contact and convective heating, cracks form in the leaves and stalks of the tea mass, partial oxidation of the phenolic compounds occurs, and therefore the change in the taste properties of the sheet - the disappearance of the bitter taste typical of the phenolic compounds of the fresh sheet; destruction of chlorophyll is achieved tea leaf, due to which it loses its green color and acquires an olive tint, destruction of a number of compounds causes the smell of green in tea aroma, such as hexenol aldehyde and alcohol hexenal. Along with intensive and complete fixation of the tea leaf, roasting in the lower drum 4 of the secondary treatment, intensive evaporation of moisture from the tea leaf and removal of the formed peers from the drum by means of an artificial blowing agent, heat agent, i.e., a mixture of combustion products and air, occurs. As a result of supplying the heat agent to the inside of the drum 4, the humidity of the tea leaf when leaving it reaches the technological norm (57-62%). At the same time, the subsequent technological process of processing the tea leaf - twisting occurs in optimal conditions without additional drying of the roasted tea leaf.

Thermal agent - products of combustion after flowing around the drums, through a fan is fed into the bottom drum and is additionally used for roasting and drying the tea leaf, which leads to an increase in thermal efficiency of the device.

The proposed device provides uniform and high-grade and high-quality heat treatment of the tea leaf by uniform heating of the entire working surface of each drum, which is achieved as a result of gas

burners under the lower drum along its entire working length. The uniform and complete heat treatment of the tea leaf is also enhanced by the supply of a heat agent in the bottom drum after it

0 wrapped around the lower and upper bar of the bans. As a result of uniform, full and high-quality heat treatment of the tea leaves, the quality of the target product, green tea and lao cha, is improved. Uniform

Warming up the entire working surface of each drum also leads to an increase in the service life of the installation, since with uniform heating there is no danger of bending and deformation of the drums.

0V the proposed device as

engine for all moving mechanisms used only one electric motor, which simplifies the design of the device and makes it less bulky compared to

5 with a prototype.

The use of gas fuel (natural and liquefied) for heating drums using infrared burners, as well as the presence of a filter and air conditioner in the device, reduces the amount of carcinogenic substances in the coolant when it is fed into the lower drum, the products are clean, there are no harmful impurities and alien za5 groin, sanitary sanitation increases.

By setting the top drum

the height of the lower drum decreases and

device design is simplified so

how are eight rollers used

0 instead of sixteen. In addition, the accuracy of the position of the upper drum is improved and the drum beats are relative to each other, which reduces the gear noise between the drums and

5 increases the reliability and service life of the device.

Making the common shaft of the feed and transition screws of the upper drum hollow facilitates the design, eliminates

0 the use of an additional pipe to divert water peers from the upper drum and creates conditions for the transfer of a certain part of the heat to the tea leaf from the water vapor removed through the walls of the single shaft, the feed screw and the transition screw.

Claims (2)

Claim 1. Device for roasting the tea leaves, including a heat insulated casing with two drums installed one above the other rotatably by means of a drive and having loading and filling augers, conveyors for supplying and discharging tea leaves, a heat source for heating the drums and a fan, characterized in that, in order to improve the quality of the target product, reliability and thermal efficiency of the device, the shafts of the loading screws of the drums are hollow, the heat-insulated casing has a channel for communication of its upper part with the cavity of the lower drum through the fan and the hollow shaft of the loading screw, and the heat generator i is made in the form of gas burners of infrared radiation uniformly installed under the lower drum along its entire length with the possibility adjusting the distance to its surface 2. The device according to claim 1. about tl and ch and y yu e with the fact that. in order to simplify the design, the feed screws are rigidly connected with drums using transitional augers, and conveyors for feeding and draining tea leaves are kinematically connected with drums in the same vertical plane.  / 1 Ugat , ( W S A eight 4gr. { 38 L 38 33 FV7V / 9h / ti MSH W V UCH VPTgV r rrTWVVVTy ЈS 86S09il 26 in-in