CN111685197A - Tea vacuum pressure-variable rolling and drying device and method - Google Patents

Abstract

The invention relates to a tea leaf vacuum pressure-variable rolling and drying device which comprises a rolling machine, a sealed bin, a vacuum pump and an air guide pipe. The rolling machine is fixed in the sealed bin, and the rolling disc is a heating plate type rolling disc. The exhaust device pumps and exhausts the gas in the sealed cabin, and the relative pressure in the sealed cabin is-0.020 MPa to-0.098 MPa in stages. The tea making raw materials are placed on a rolling machine in a sealed cabin for rolling, heating and drying, and the heating plate type rolling disc conducts heat conduction heating on the tea leaves which are rolled and dried at the same time when the exhaust device vacuumizes. The vacuum rolling and drying process reduces the heat sensitivity of the tea, improves the oxidation resistance of the tea, uniformly heats, rolls and dries the tea in a vacuum variable-pressure rolling and drying state, ensures that the rolled tea is well bundled and has good soaking resistance, improves the chemical component content of the tea, and increases the liquor color, efficacy and taste of the tea.

Description

Tea vacuum pressure-variable rolling and drying device and method

Technical Field

The invention relates to a rolling device for tea making raw materials, in particular to a tea vacuum variable-pressure rolling and drying device.

Background

The tea making raw materials are flowers, branches and leaves of plants; the tea making raw material after being roasted is placed into a rolling machine for rolling, which is an important link in tea making processing. The kneading machines on the market today have four problems: 1. the plant cells of the tea making raw materials are not easy to break, the plant cells can be extruded and broken only by mutual heavy pressing of the pressing disc and the rolling disc, the fiber tissues of the tea making raw materials are damaged by the mutual heavy pressing and the rolling, and the rolling shape of the tea is influenced. 2. Tea juice squeezed from tea making raw materials by rolling flows to the outside of the rolling disc along the top surface of the rolling disc, so that the quality of the tea is reduced. 3. During rolling, chlorophyll in the raw materials is subjected to enzymatic oxidation under the action of oxygen in the air to form a large amount of dark brown pheophytin, and the tea leaves are yellow. 4. In the rolling process of tea making raw materials, the raw materials in the rolling barrel are easy to cause stuffy yellow taste due to high temperature, and the color and aroma of the tea are influenced. 5. After the tea making raw materials are rolled, the tea is often loose due to untimely drying, and the tea soaking resistance is reduced. In conclusion, the kneading machines on the market do not have the function of simultaneously solving the above five problems, resulting in the overall quality degradation of tea leaves.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, researches the quality transformation mechanism in the tea processing process by knowing the physical characteristics of heat sensitivity, low oxidation, high activity and the like of tea making raw materials, and provides a tea vacuum pressure-swing rolling and drying device.

In order to achieve the purpose, the invention is realized by the following technical scheme: a tea drying device with vacuum variable-pressure rolling comprises a rolling machine, a sealed bin, an exhaust device, an air duct and a sealing door.

The sealed cabin is a sealed cabin device made of metal, and the inside of the sealed cabin is sealed and airtight.

The appearance of the sealed cabin is cylindrical, the diameter of the cylindrical sealed cabin is 1500-2800 mm, and the height of the cylindrical sealed cabin is 1800-3800 mm. The bin body of the cylindrical sealed bin is a metal plate, the metal plate is made into a cylindrical metal tube through rolling and welding, and the upper end and the lower end of the metal tube are sealed and fixed by the metal plate. The upper end of the metal cylinder is conical or round; the lower end of the metal cylinder is planar, and the bin body at the lower end of the plane is convenient for installing the rolling machine. The conical or round-head upper-end cabin body improves the vacuum compression resistance of the sealed cabin, and the inside of the cylindrical sealed cabin is sealed and airtight.

The appearance of the sealed cabin is square, the length of the square sealed cabin is 1200-2800 mm, the width is 1200-1800 mm, and the height is 1800-3500 mm. The bin body of the square sealed bin is formed by welding a metal frame and a metal plate into a whole in a combined mode, metal materials such as angle iron or channel steel are welded into a three-dimensional square frame, the metal plate is welded outside the metal frame, and the metal plate supported by the frame improves the vacuum pressure resistance. The upper end of the metal cylinder is conical or round; the lower end of the metal cylinder is planar, and the bin body at the lower end of the plane is convenient for installing the rolling machine. Six storehouse bodies weld and make up into a square sealed bin, and the vacuum resistance to compression degree of sealed bin has been improved to the upper end storehouse body of taper or button head form, and the inside of square sealed bin is sealed airtight.

And a port for installing a sealing door is reserved on the cabin body of the sealing cabin.

The sealing door is arranged on a reserved opening on the sealed cabin body. After the sealing door is closed, the joint of the sealing door and the cabin body is sealed and airtight, and a sealed and airtight closed space is arranged inside the sealed cabin body after the sealing door is closed.

The kneading machine selected in the present application is a kneading machine used on the market. The kneading machine on the market comprises a frame, a kneading disc, a kneading barrel, a gland, a driving motor, a crank mechanism, a control box and the like. The crank mechanism comprises a rotating shaft, a driving shaft and a crank.

The kneading disc of the kneading machine selected by the application is a heating plate type kneading disc. The other structural configurations of the rolling machine selected by the application are the same as those of the rolling machine on the market at present.

The rolling machine selected by the application is installed and fixed in the sealed bin; the driving motor of the rolling machine is connected with a power supply outside the bin through an electric wire; the lower end of the rolling machine is fixed on the bottom bin body of the sealed bin. The rolling processing flow of the rolling machine in the sealed bin is the same as the conventional rolling processing flow.

The heating plate type kneading disc comprises a bottom plate, a top plate, an electric heating pipe, a heat conducting medium and a support.

The top plate of the heating plate type kneading disc is provided with ribs, and the shape of the ribs is the same as that of the conventional ribs. The ribs of the heating plate type kneading disc are selected into ribs with proper shapes and installation quantity according to requirements.

The bottom plate all around with the roof laminate fixed as an organic whole all around, carry out fixed connection by the support of 3 at least between bottom plate and the roof, the both ends of support are fixed respectively on bottom plate and roof. The support is a metal strip or a metal angle iron. The heating plate type kneading plate with the fixed bottom plate and the fixed top plate supported by the bracket improves the pressure resistance in a vacuum state. The holder is not shown in the drawings.

The heat-conducting medium is arranged in a cavity between the bottom plate and the top plate of the heating plate type kneading disc.

The electric heating pipe is fixedly arranged on the bottom plate in the cavity between the bottom plate and the top plate of the heating plate type kneading disc, and a power supply connector of the electric heating pipe penetrates through the bottom plate and then is connected to a power supply outside the heating plate type kneading disc; the connection between the power supply connector of the electric heating pipe and the bottom plate is fixed, sealed and airtight.

After the switch of the electric heating pipe is started, the power supply connector of the electric heating pipe is connected with the power supply outside the heating plate type kneading disc, heat energy generated by the electric heating pipe conducts heat conduction and heating for the heat-conducting medium, and heat energy carried by the heat-conducting medium conducts heat conduction and heat conduction radiation through the tea making raw material on the top plate of the heating plate type kneading disc. The tea making raw materials on the top plate of the heating plate type rolling disc obtain heat when being rolled and dried, and the tea making raw materials can be rolled and dried in the rolling process.

The storehouse body that air duct one end passed the sealed bin extends in the storehouse, the mouth of pipe of air duct one end is in the inside of sealed bin, the inside of air duct and sealed bin is communicating, the junction of the storehouse body of air duct and sealed bin is fixed sealed airtight.

And the pipe orifice at the other end of the air duct is fixedly connected to the exhaust device.

The air in the sealed bin and the moisture generated during the rolling and drying of the raw materials are conveyed by the air duct and are pumped out of the sealed bin by the exhaust device. And the exhaust device performs pumping and exhausting on the gas in the sealed bin according to the set required vacuum degree. After the air pressure in the sealed cabin reaches the required vacuum degree, the exhaust device stops pumping gas; and after the air pressure in the sealed cabin is higher than the required vacuum degree, the exhaust device starts to pump and exhaust gas.

The exhaust device is a vacuum pump or a Roots blower.

According to the requirements of different qualities and shapes of tea leaves of different classifications, different rolling and drying are carried out, and the rolling and drying are the primary shaping stage of tea leaves. The kneading pressure should be controlled as "light, heavy and light": since tea leaves are still weak at the beginning, tea juice is not broken and is not twisted, the tea leaves are slightly pressed and twisted; when the tea leaves are wet, the tea leaves are squeezed out, so that the tea leaves can be heavily twisted, and the tea leaves are synchronously dried during the heavy rolling, so that the tea juice is adhered to the tea leaves; and finally, basically forming the tea leaves, preventing the tea leaves from being broken into strips, slightly pressing and twisting the tea leaves as much as possible, synchronously drying the tea leaves when the tea leaves are soft, and shaping the twisted tea leaves.

Tea leaf vacuum pressure-swing rolling drying principle: the tea making raw material is treated by staged vacuum pressure-variable rolling and drying in a sealed bin with relative pressure lower than atmospheric pressure. According to different requirements of staged rolling of tea, different vacuum degrees of variable pressure are selected to enter rolling processing according to the stages of vacuum light rolling, vacuum heavy rolling and drying.

The tea leaf vacuum pressure-changing rolling and drying process is a process of placing rolled and dried tea making raw materials on a rolling machine in a sealed cabin for rolling, heating and drying, vacuumizing by using an exhaust device, and simultaneously conducting staged heat conduction and heating on the tea leaves which are rolled and dried at the same time, so that the moisture in the tea leaves is diffused to the surface through pressure difference or concentration, water molecules obtain enough kinetic energy on the surface of the tea leaves, and the water molecules escape to a low-pressure space of the sealed cabin after overcoming the mutual attraction among the molecules, so that the water molecules are pumped away by the exhaust device.

The tea leaf vacuum pressure-swing rolling drying method comprises the following steps: the first step is as follows: feeding: the tea making raw materials to be kneaded are placed in a heating plate type kneading disc and a kneading barrel of a kneading machine in a sealed bin, then a sealing door is closed, an exhaust device is started, the exhaust device exhausts gas in the sealed bin, a negative pressure state is formed around the tea making raw materials in the sealed bin, and the relative pressure in the sealed bin is-0.020 MPa-0.098 MPa. The air quantity of the air with the pressure of-0.020 MPa to-0.098 MPa in the sealed cabin after air extraction is reduced by 20-98% relative to the air quantity of the normal pressure, and the oxygen in the corresponding air is also reduced by 20-98%.

The second step is that: carrying out vacuum light rolling: the tea leaves just placed on the heating plate type rolling disc are weak, the tea juice is not rolled out, and the rolling pressure should be controlled to be light. After the switch of the electric heating pipe is started, heat energy generated by the electric heating pipe conducts heat conduction and heating on the heat-conducting medium, and heat energy carried by the heat-conducting medium conducts heat conduction and heat conduction radiation through the tea making raw materials on the top plate of the heating plate type rolling disc. The temperature of the heat-conducting medium is 60-80 ℃.

Starting a driving motor of the rolling machine, and starting the rolling machine to roll and process the tea making raw materials. The sealed cabin under the negative pressure state only has 20 ~ 98% air of original ordinary pressure in the storehouse, knead the oxygen in the sealed cabin of drying process only has the oxygen of original ordinary pressure air 2 ~ 80%, the tea-making raw materials slightly kneads in the negative pressure of hypoxemia in the sealed cabin storehouse, hypoxemia in the sealed cabin storehouse can restrain the enzymatic oxidation of tea polyphenol etc. in the raw materials, has avoided forming the pheophytin that a large amount of dark brown takes off, the tealeaves colour obtains the fixation can not the brown stain.

According to different tea making raw materials, the vacuum light rolling time is 2-30 minutes. After the tea leaves are slightly rolled in vacuum, the water content of the tea leaves is about 55-70%.

The third step: and (3) vacuum heavy rolling and drying: under the combined action of resistance and friction of ribs of the heating plate type kneading disc, kneading cylinder and pressing cover force and other forces in various directions, plant cells with internal and external pressure difference are broken under the mutual extrusion action generated by the kneading disc and the pressing cover, and juice in the plant cells diffuses and overflows on the surface of the raw material. Because the plant cells of the tea making raw materials form a negative pressure state, the extrusion force generated by the rolling disc and the gland during rolling the raw materials is small, the shape of the tea making raw materials is protected by rolling with small pressure, and the quality of the tea making raw materials after the tea is rolled in a vacuum pressure-changing manner is optimized.

The heat energy generated by the electric heating pipe conducts heat for the heat-conducting medium, and the temperature of the heat-conducting medium is 80-120 ℃. The heat energy carried by the heat-conducting medium is conducted heat conduction heating of heat conduction and heat radiation through the tea making raw materials on the top plate of the heating plate type kneading disc.

The exhaust device pumps moisture in the sealed cabin, the relative pressure in the sealed cabin is-0.030 Mpa-0.098 Mpa, in the continuous process of pumping moisture by the exhaust device, only stored oxygen is carried by the moisture ceaselessly and pumped out, the oxygen in the sealed cabin in the vacuum re-rolling drying process only has 1-10% of oxygen in original normal pressure air, the sealed cabin is sealed and airtight, and the air in the sealed cabin is in a low-oxygen state. The hypoxia in the air in the sealed bin can inhibit the enzymatic oxidation of tea polyphenol and the like in the raw materials, so that the formation of a large amount of dark brown pheophytins is avoided, and the color of tea leaves is fixed and can not be browned. The tea leaves in the vacuum pressure-variable rolling and drying state are heated, so that the rolled tea leaves are well rolled and have good soaking resistance.

The tea making raw material in the sealed bin is in a negative pressure state around, the vacuum degree corresponds to the water boiling point of the tea juice, and the water in the raw material absorbs heat when being vaporized. Therefore, the high temperature on the heating plate type kneading disc and the raw material in the kneading barrel is cooled when the water in the raw material is vaporized, so the tea leaves can not generate the yellow and stuffy taste due to high humidity and high temperature.

The vacuum rolling and drying process reduces the heat sensitivity of the tea and improves the oxidation resistance of the tea. The boiling point of the water in the tea juice is reduced along with the increase of the vacuum degree under the vacuum negative pressure state, the water in the tea juice which overflows after being squeezed by the raw material plant cells is vaporized after being heated, and tea polyphenols, tea pigments, tea polysaccharide, tea saponin, tea pigments, caffeine, protein, amino acid, alkaloid, mineral substances and other substances in the tea juice are adhered to the tea. The tea juice does not flow to the lower part of the kneading disc. The components of the tea are rolled and dried at a low temperature in vacuum and in an oxygen-free state to obtain the maximum preservation, the chemical component content of the tea is further improved by the vacuum rolled and dried tea, and the liquor color, the efficacy and the taste of the tea are increased.

According to different tea making raw materials, the vacuum re-rolling drying time is 5-30 minutes, and after the vacuum re-rolling drying is finished, the water content of the tea is about 50-65%.

The fourth step: and (3) carrying out vacuum light rolling and drying: tea leaves are basically shaped, and the kneading of the tea leaves into strips is prevented and needs to be as light as possible. The heat energy generated by the electric heating pipe conducts heat to the heat-conducting medium, and the temperature of the heat-conducting medium is 80-160 ℃. The heat energy carried by the heat-conducting medium is conducted heat conduction heating of heat conduction and heat radiation through the tea making raw materials on the top plate of the heating plate type kneading disc.

The exhaust device pumps and exhausts moisture in the sealed cabin, and the relative pressure in the sealed cabin is-0.050 MPa to-0.098 MPa

The water content in the tea leaves is reduced along with the increase of the vacuum degree under the vacuum negative pressure state, and meanwhile, the moisture is reduced by the aid of the moisture extraction of the exhaust device, so that the solution such as juice in the tea leaves obtains enough kinetic energy to be separated from the surface of the tea leaves.

According to the temperature needed by the rolled tea leaves, after the air and moisture in the sealed bin are exhausted through the exhaust device, the pressure in the sealed bin reaches the corresponding set relative pressure, and the rolled tea leaves are dried.

According to different tea making raw materials, the vacuum light rolling drying time is 3-20 minutes, and after the tea leaves are subjected to vacuum light rolling drying, the water content of the tea leaves is about 45% -60%.

Fifthly, discharging: and (5) opening the sealing door, and taking out the rolled and dried tea leaves. The rolled tea raw material enters the next tea processing procedure.

Compared with the prior rolling device, the rolling device has the following beneficial effects: a tea drying device with vacuum pressure-variable rolling comprises a rolling machine, a sealed bin, a vacuum pump and an air duct. The rolling machine is fixed in the sealed bin, and the rolling disc is a heating plate type rolling disc. The exhaust device pumps and exhausts the gas in the sealed cabin, and the relative pressure in the sealed cabin is-0.020 MPa to-0.098 MPa in stages. The tea making raw material is placed on a rolling machine in a closed sealed bin for rolling, heating and drying, the exhaust device vacuumizes, and the heating plate type rolling disc conducts staged heat conduction heating on the tea leaves which are rolled and dried simultaneously. The vacuum rolling and drying process reduces the heat sensitivity of the tea, improves the oxidation resistance of the tea, uniformly heats, rolls and dries the tea in a vacuum variable-pressure rolling and drying state, ensures that the rolled tea is well bundled and has good soaking resistance, improves the chemical component content of the tea, and increases the liquor color, efficacy and taste of the tea.

Description of the drawings:

FIG. 1 is a schematic structural view of a tea leaf vacuum pressure-swing rolling and drying device according to the present invention;

fig. 2 is a schematic structural view of a heating plate type kneading disc of the kneading machine of the present invention;

FIG. 3 is a processing flow of the tea leaf vacuum pressure-swing rolling and drying method of the present invention.

In the figure: 1. the kneading machine comprises a kneading machine body 2, a sealed cabin 3, an exhaust device 4, an air guide pipe 5, a sealing door 6, a heating plate type kneading disc 7, ribs 8, a bottom plate 9, a top plate 10, an electric heating pipe 11, a heat conducting medium 12 and a cabin body.

The specific implementation mode is as follows:

the invention is further described below with reference to the accompanying drawings and examples.

Example (b):

referring to fig. 1 and 2, the tea leaf vacuum pressure-swing rolling drying device comprises a rolling machine 1, a sealed bin 2, an exhaust device 3, an air duct 4 and a sealing door 5.

The sealed cabin 2 is a sealed cabin device.

The appearance of the sealed cabin 2 is cylindrical, the diameter of the cylindrical sealed cabin 2 is 1800mm, and the height is 2800 mm.

The sealing door 5 is arranged on a reserved opening on the cabin body 12 of the sealing cabin 2, and the joint of the sealing door 5 and the cabin body 12 is sealed and airtight.

The rolling machine 1 comprises a frame, a rolling disc, a rolling barrel, a gland, a driving motor, a crank mechanism and a control box.

The kneading disc of the kneading machine 1 is a heating plate type kneading disc 6.

The rolling machine 1 is fixedly arranged in the sealed bin 2; the driving motor of the rolling machine 1 is connected to a power supply outside the bin through an electric wire.

The heating plate type kneading disc 6 comprises a bottom plate 8, a top plate 9, an electric heating pipe 10, a heat conducting medium 11 and a support.

The top plate 9 of the heating plate type kneading disc 6 is provided with a rib 7.

The periphery of the bottom plate 8 and the periphery of the top plate 9 are fixedly integrated in an attaching mode, two ends of the support are fixed to the bottom plate 8 and the top plate 9 respectively, and the support is a metal strip.

The heat-conducting medium 11 is arranged in a cavity between the bottom plate 8 and the top plate 9 of the heating plate type kneading disc 6, and the electric heating pipe 10 is fixedly arranged on the bottom plate 8 in the cavity between the bottom plate 8 and the top plate 9 of the heating plate type kneading disc 6.

After the switch of the electric heating pipe 10 is started, the heat energy generated by the electric heating pipe 10 conducts heat conduction and heating on the heat-conducting medium 11, and the heat energy carried by the heat-conducting medium 11 conducts heat conduction and heating of heat conduction and heat radiation through the tea making raw material on the top plate 9 of the heating plate type kneading disc 6.

One end of the air duct 4 passes through the bin body 12 of the sealed bin 2 and extends into the bin, and the joint of the air duct 4 and the bin body 12 of the sealed bin 2 is fixed, sealed and airtight.

The pipe orifice at the other end of the air duct 4 is fixedly connected with the exhaust device 3. Air in the sealed bin 2 and moisture generated during the rolling and drying of the raw materials are conveyed by the air guide pipe 4 and are pumped out of the sealed bin 2 by the exhaust device 3.

The exhaust means 3 is a vacuum pump.

The tea making raw material is processed by staged vacuum pressure swing rolling and drying in a sealed bin 2 with the relative pressure lower than the atmospheric pressure. According to different requirements of staged rolling of tea, different vacuum degrees of variable pressure are selected to enter rolling processing according to the stages of vacuum light rolling, vacuum heavy rolling and drying.

The tea leaf vacuum pressure-swing rolling drying method shown in figure 1 and figure 3 comprises the following steps: the first step is as follows: feeding: placing the tea making raw materials to be kneaded in a heating plate type kneading disc 6 and a kneading barrel of a kneading machine 1 in a sealed bin 2, and then closing a sealing door 5; and starting the exhaust device 3, and exhausting the gas in the sealed cabin 2 by the exhaust device 3.

The second step is that: carrying out vacuum light rolling: after the switch of the electric heating pipe 10 is started, the heat energy generated by the electric heating pipe 10 conducts heat conduction and heating on the heat-conducting medium 11, and the heat energy carried by the heat-conducting medium 11 conducts heat conduction and heating of heat conduction and heat radiation through the tea making raw material on the top plate 9 of the heating plate type kneading disc 6. The temperature of the heat transfer medium 11 is 80 ℃. Starting a driving motor of the rolling machine 1, wherein the relative pressure in the sealed bin 2 is-0.055 Mpa, the rolling machine 1 starts rolling and processing tea making raw materials, and the vacuum light rolling time is 10 minutes; after the vacuum light rolling and drying, the water content of the tea leaves is about 65 percent.

The third step: and (3) vacuum heavy rolling and drying: the relative pressure in the sealed bin 2 is-0.060 Mpa, and a negative pressure state is formed around the tea making raw material in the sealed bin 2. Under the combined action of the resistance and friction of the ribs 7 of the heating plate type kneading disc 6, the kneading cylinder and the pressing cover, and other forces in various directions, the raw material plant cells with internal and external pressure difference are broken under the mutual extrusion action generated by the kneading disc and the pressing cover, and the juice in the raw material plant cells is diffused and overflows on the surface of the raw material.

The heat energy generated by the electric heating tube 10 conducts heat to the heat-conducting medium 11, and the temperature of the heat-conducting medium 11 is 80 ℃. The heat energy carried by the heat-conducting medium 11 is heated by heat conduction and heat radiation through the tea making raw material on the top plate 9 of the heating plate type kneading disc 6. The high temperature on the heating plate type kneading disc 6 and the raw material in the kneading barrel is cooled when the water in the raw material is vaporized, so the tea leaves can not generate the yellow and stuffy taste due to high humidity and high temperature.

The water in the tea juice which overflows after being squeezed by the plant cells of the raw materials is vaporized after obtaining heat, and the substances in the tea juice are adhered to the tea leaves. The exhaust device 3 pumps moisture in the sealed bin 2, components of the tea are rolled and dried at a vacuum low temperature in an oxygen-free state to obtain the maximum preservation, the chemical component content of the tea is further improved by the vacuum rolled and dried tea, and the liquor color, the efficacy and the taste of the tea are increased. The vacuum re-rolling drying time was 15 minutes and the tea moisture content was about 60%.

The fourth step: and (3) carrying out vacuum light rolling and drying: the heat energy generated by the electric heating pipe 10 conducts heat conduction and heating on the heat-conducting medium 11, and the temperature of the heat-conducting medium 11 is 120 ℃; the exhaust device 3 pumps moisture in the sealed cabin 2, and the relative pressure in the sealed cabin 2 is-0.094 Mpa. The water content in the tea leaves is reduced along with the increase of the vacuum degree under the vacuum negative pressure state, and meanwhile, the moisture content is reduced by the aid of the moisture extraction of the exhaust device 3, so that the solutions such as juice in the tea leaves and the like obtain enough kinetic energy to be separated from the surfaces of the tea leaves.

The drying time for the light rolling under vacuum was 10 minutes and the moisture content of the tea leaves was about 50%.

Fifthly, discharging: after the sealing door 5 is opened, the rolled and dried tea leaves are taken out. The rolled tea raw material enters the next tea processing procedure.

The above embodiments are only used to help understand the manufacturing method and the core concept of the present invention, and the specific implementation is not limited to the above specific embodiments, and those skilled in the art can make changes without creative efforts from the above concepts, which all fall within the protection scope of the present invention.

Claims (2)

1. A tea vacuum variable-pressure rolling and drying device comprises a rolling machine (1), a sealed bin (2), an exhaust device (3), an air duct (4) and a sealing door (5); the rolling machine (1) comprises a frame, a rolling disc, a rolling barrel, a gland, a driving motor, a crank mechanism and a control box; the method is characterized in that: the kneading disc of the kneading machine (1) is a heating plate type kneading disc (6);

the heating plate type kneading disc (6) comprises a bottom plate (8), a top plate (9), an electric heating pipe (10), a heat-conducting medium (11) and a bracket; the top plate (9) is provided with a rib (7); the periphery of the bottom plate (8) and the periphery of the top plate (9) are fixedly attached into a whole, and two ends of the support are respectively fixed on the bottom plate (8) and the top plate (9);

the sealing door (5) is arranged on a reserved opening on the cabin body (12) of the sealing cabin (2), and the joint of the sealing door (5) and the cabin body (12) is sealed and airtight;

the rolling machine (1) is fixedly arranged in the sealed bin (2), and a driving motor of the rolling machine (1) is connected to a power supply outside the bin through an electric wire;

the heat-conducting medium (11) is arranged in a cavity between a bottom plate (8) and a top plate (9) of the heating plate type kneading disc (6); the electric heating pipe (10) is fixedly arranged on the bottom plate (8) in the cavity between the bottom plate (8) and the top plate (9) of the heating plate type kneading disc (6); the heat energy generated by the electric heating pipe (10) conducts heat conduction and heating on the heat-conducting medium (11), and the heat energy carried by the heat-conducting medium (11) conducts heat conduction and heat conduction radiation through the tea making raw material on the top plate (9) of the heating plate type kneading disc (6);

one end of the air duct (4) passes through the bin body (12) of the sealed bin (2) and extends into the bin; the pipe orifice at the other end of the air duct (4) is fixedly connected to the exhaust device (3); air in the sealed cabin (2) and moisture generated during the rolling and drying of the raw materials are conveyed by the air guide pipe (4) and pumped out of the sealed cabin (2) by the exhaust device (3), and the relative pressure in the sealed cabin (2) is-0.020 MPa to-0.098 MPa.

2. A tea vacuum pressure-swing rolling drying method is characterized in that: the tea making raw materials are rolled and dried in a sealed bin (2) with the relative pressure lower than the atmospheric pressure;

firstly, feeding: placing the tea making raw materials to be kneaded in a heating plate type kneading disc (6) and a kneading barrel of a kneading machine (1) in a sealed bin (2), and closing a sealing door (5); starting the exhaust device (3), wherein the exhaust device (3) pumps and exhausts the gas in the sealed bin (2);

secondly, slightly rolling in vacuum: the relative pressure in the sealed bin (2) is-0.020 MPa to-0.098 MPa; after the switch of the electric heating pipe (10) is started, heat energy generated by the electric heating pipe (10) conducts heat conduction and heating on the heat-conducting medium (11), and heat energy carried by the heat-conducting medium (11) conducts heat conduction and radiation through the tea making raw materials on the top plate (9) of the heating plate type rubbing disc (6); the temperature of the heat-conducting medium (11) is 60-80 ℃; starting a driving motor of the rolling machine (1), starting the rolling machine (1) to roll and process tea making raw materials, wherein the vacuum light rolling time is 2-30 minutes;

thirdly, vacuum heavy rolling and drying: the relative pressure in the sealed bin (2) is-0.030 Mpa-0.098 Mpa, negative pressure state is formed around the tea making raw material in the sealed bin (2), the tea making raw material is subjected to the composite action of resistance and friction of the rib 7 of the heating plate type kneading disc (6), the kneading cylinder, the gland pressing force and other forces in various directions, and the raw material plant cells with internal and external pressure difference are broken under the mutual extrusion action generated by the kneading disc and the gland;

the heat energy generated by the electric heating pipe (10) conducts heat conduction and heating on the heat conduction medium (11), and the temperature of the heat conduction medium (11) is 80-120 ℃; the heat energy carried by the heat-conducting medium (11) is subjected to heat conduction and heat conduction radiation heat conduction heating through the tea making raw materials on the top plate (9) of the heating plate type rubbing plate (6), the raw material plant cells break through the water in the overflowing tea juice to obtain heat and then vaporize the heat, and the exhaust device (3) exhausts the moisture in the sealed bin (2); the vacuum heavy rolling drying time is 5-30 minutes;

fourthly, carrying out vacuum light rolling and drying: the heat energy generated by the electric heating pipe (10) conducts heat conduction and heating on the heat conduction medium (11), and the temperature of the heat conduction medium (11) is 80-160 ℃; the exhaust device (3) pumps moisture in the sealed bin (2), the relative pressure in the sealed bin (2) is-0.050 Mpa to-0.098 Mpa, and the vacuum light rolling drying time is 3-20 minutes;

fifthly, discharging: after the sealing door (5) is opened, the dried tea making raw material is taken out and twisted.

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