JPH0378971B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for heat treating green tea leaves for inactivating oxidizing enzymes in green tea leaves and supplying the tea leaves to a subsequent tea manufacturing line.

[Background technology and problems]

Conventionally, the heat treatment for killing the oxidizing enzymes of green tea leaves in the production of green tea has been called steaming, in which a large amount of steam is blown onto the green tea leaves and the leaves are heated using the latent heat.

In recent years, attempts have been made to solve the drawbacks of the steam heating method, such as Japanese Utility Model Publication No. 30696/1983 and Japanese Patent Publication No. 1983/1983.
There are methods and apparatuses for immersing fresh tea leaves in hot water and boiling them, as found in Japanese Patent Publication No. 1849 and Japanese Patent Application Laid-Open No. 60-58036.

However, even with these methods, a special device is required to immerse and move the tea leaves in the hot water, and the temperature of the hot water in the bath tends to be uneven, and the tea leaves are not easily immersed in the hot water. Problems still remained, such as the tendency for uneven processing due to insufficient stirring.

[Purpose of the invention]

The present invention was made in view of the current situation, and uses air bubbles to stir the tea leaves in the hot water and the hot water itself, thereby solving the temperature deviation of the hot water in the tank and the lack of stirring of the tea leaves. The present invention aims to provide a heat treatment method for green tea leaves and a heat treatment apparatus that implements the method and eliminates the need for special mechanical members for immersing tea leaves in hot water.

[Summary of the invention]

Therefore, in the first invention, a stream-like flow of hot water is created in a flow path formed in a hot water tank, air bubbles are generated in this flow, and green tea leaves dropped into the hot water at the upstream are exposed to air bubbles. This method is characterized by a heat treatment method for green tea leaves, in which the leaves are allowed to flow downstream while being stirred by flotation and sedimentation, and are then scooped up by a belt conveyor and taken out from the boiling water. In the second invention, a partition wall is provided in a hot water tank covered with heat insulating material to form a flow path, an air guide pipe with a large number of blowholes is submerged in the flow path, and at the end of the flow path. A discharge port is opened, and the starting end of a belt conveyor that slopes upward and projects out of the water tank is installed so that a portion slightly ahead of the starting end is immersed in hot water to cover the discharge port, and an air guide pipe and an air pump are installed. The apparatus is characterized in that the starting end of the flow path is connected to a return flow path from the discharge port, and the flow path is provided with a hot water flow starting device and a hot water heating device.

〔Example〕

Therefore, first, the apparatus of the present invention will be explained with reference to the illustrated embodiment, and then the method of the present invention will be explained together with an explanation of the operation of the apparatus of the embodiment.

The green tea leaf heat treatment apparatus 1 mainly includes a hot water tank 3 disposed on a machine frame 2, a belt conveyor 4 whose starting end is immersed in the boiling water of the hot water tank 3, and a belt conveyor 4 that generates a flow of hot water in the hot water tank. A circulatory system 5, a refill water supply system 6 that sprays finishing cooling water and replenishes the hot water tank 3, an air supply system 7 that generates air bubbles in the hot water, etc., and a system that keeps the hot water in the hot water tank 3 warm.
It consists of a hot water heater system 8 etc. for heating.

The hot water tank 3 is a rectangular parallelepiped hot water tank with a length of 2 m, a width of 1 m, and a depth of about 0.4 m.A heat insulating material is stretched around the periphery and the bottom of the hot water tank. A shaped partition wall 9 is provided to form an approximately letter-shaped flow path that goes around the outer periphery and then goes around the inner periphery, and sand and mud sedimentation grooves 10 are provided at the bottom of the flow path before the first corner and before the fourth corner. will be established. Further, a wire mesh is provided above the groove, and furthermore, both grooves are connected to each other by piping at the bottom thereof, and an overflow pipe 11 is connected to this.

The tip 11a of the overflow pipe 11 has an overflow structure corresponding to the vicinity of the upper surface of the hot water tank 3, and its discharge height can be adjusted up and down by the up and down adjustment mechanism 12.

Further, 13 is a sand and mud discharge valve.

The starting end of the outer periphery and the bottom of the end of the inner periphery, which are formed in a substantially oval shape, are opened wide to serve as a water inlet 14 and a discharge port 15, respectively. Connected with a U-shaped communication pipe 16 inside,
This communication pipe 16 is configured as a hot water tank with an underground tunnel.

This communication pipe 16 is a part of the hot water circulation system 5 that circulates the hot water in the hot water tank 3 so that it goes around the outer periphery of the flow path and then goes around the inner periphery. It has a straight hanging part 16a, and a drain pot 17 is attached to the lowermost horizontal part.

In addition, a motor 18 whose rotational speed can be controlled is attached to the hot water tank outer frame 2 adjacent to the water outlet 14 so that its axis 18a is in the vertical direction.
The shaft 19a of the screw 19 is the motor shaft 1.
8a, and these two shafts 18a,
19a is connected with a pulley and a belt to form a hot water flow starting device. The hot water circulation system 5 is configured as described above.

The belt conveyor 4 is arranged so that its starting end is slightly submerged in the hot water, and the submerged part covers the discharge port 15 of the hot water tank 3.
It is provided in an inclined shape so that its tip rises from the end of the flow path and largely protrudes outside the hot water tank 3.

This belt conveyor 4 uses an air-permeable net belt made of heat-resistant polyester as a belt, and rolls 4 that are pivotally supported at both ends of the conveyor frame.
It spans between a and 4a and can be driven by a motor 20 at the tip.

Next, the air supply system 7 will be explained.

The air supply system 7 consists of an air guide pipe that generates air bubbles in the hot water tank and a fumarole pipe that removes leaves remaining on the belt conveyor. This is a steel pipe that is attached to the hot water tank 3 in a state that is slightly raised from the bottom, covering almost the entire area of the flow path and the part submerged in the hot water at the starting end of the belt conveyor 4,
It is connected to an air pump 23 housed within the hot water tank outer machine frame 2 and piping 24. At this time, a particularly large number of blowholes are provided in the air guiding pipe located near the starting end of the flow path.

On the other hand, the fumarole pipe 25 is installed in the tip turning part of the belt conveyor 4 in a direction perpendicular to the belt, and has a large number of fume holes 26 bored facing the back side of the belt, and is connected to the air pump 23 and the air guide pipe 21. Piping 24
A branch pipe 27 is formed from the branch pipe 27.

In the hot water heater system 8, similarly to the air guide pipe 21, a steam pipe 29 made of a steel pipe in which a large number of steam outlets 28 are bored is stacked and arranged in parallel with the air guide pipe 29, and a boiler 30 is separately connected to the steam pipe 29 by a pipe 30a. , by introducing steam into boiling water.

Next, the heat-treated tea leaves scooped up onto the belt conveyor 4 are finished washed with clean water, and at the same time the tea leaves are cooled.Furthermore, some of the waste water is transferred to the boiling water tank 3 as make-up water, and most of the other A supplementary water supply system 6 will be described in which the waste water is collected and filtered as it is and then supplied again as water for finishing cooling.

Reference numeral 31 denotes a water sprinkling pipe, which is disposed on the conveyor from slightly above the inside of the hot water tank 3 where the belt conveyor 4 is exposed to the hot water, to the tip of the belt conveyor 4, and has a number of water sprinkling ports 32 perforated therein. At least one of them is placed on a conveyor located above the inside of the hot water tank 3, and a water supply pipe 33 is communicated with the conveyor in the middle.

On the lower surface of the belt conveyor 4 that protrudes outside the hot water tank 3, a falling collection chute 3 is installed according to the slope of the belt conveyor 4.
4 is suspended, and an induction chute 35 which is inconsistent with this is placed at the lower end of the chute, and a first filtration tank 36 is placed below it.
Attach it to the side of the machine frame 2, facing it.

The first filtration tank 36 has a built-in sea line-shaped filtration member, and is located near the top surface of the tank 36 on the machine frame shelf 2a next to the second filtration tank 37 housed below the machine frame 2 at a different level. A supernatant take-out port 38 opened to the second filtration tank 37 is provided.

An opening is formed in the second filtration tank 37 to connect piping 40 to the water suction side of the water supply pump 39,
An automatic water supply device 42 connected to a water pipe 41 is housed inside.

On the other hand, the water discharge side of the water supply pump 39 and the water sprinkling pipe 3
1 through a water supply pipe 33.

Next, the equipment installed before and after the green tea leaf heat treatment apparatus 1 will be explained.

Reference numeral 43 denotes a leaf feeder that faces the starting end of the flow path formed in the hot water tank 3 from above, and its delivery speed etc. can be adjusted freely.

In addition, 45 is a batch-type dehydrator with a high-speed rotatable dehydration tank that can be reversed at any time, and the belt conveyor 4
It is placed below the tip and next to the input device 46 which also has a temporary storage function.

[Effect]

First, how to boil the hot water in the hot water tank 3 and how to keep it warm will be explained.

Boiling water and keeping it warm can be done, for example, by directly supplying hot water from the boiler can into the hot water tank 3, or by directly heating the bottom of the hot water tank with the combustion flame of a burner. We decided to boil the water in tank 3.

That is, water from a separate water hose is introduced into the hot water tank 3, and after being injected to a predetermined depth, the boiler 30
The steam was introduced into the steam pipe 29 to generate steam bubbles in the water, and while the steam bubbles rose to the surface of the water, the heat held by the steam was applied to the water to heat it.

Therefore, the water in the tank eventually becomes boiling water,
Furthermore, by adjusting the amount of steam thereafter, the temperature of the hot water can be kept as is.

At this time, since the amount of heat held by the steam is constant and there are no unstable factors in combustion efficiency, the temperature of the hot water can be easily controlled by adjusting the amount of steam.

Next, the flow of hot water in the hot water tank 3 will be explained.

When the motor 18 is driven, its rotation is transmitted to the screw 19, which rotates, and the hot water in the communication pipe 16 is pushed out to the outlet 14, and the hot water at the end of the flow path is sucked into the communication pipe 16, and the flow path is A flow of hot water is generated along a channel with the starting end being upstream and the end of the channel being downstream. The speed of this flow is adjusted by controlling the rotational speed of motor 20.

If there are tea leaves in this hot water stream, they are flowed downstream and undergo heat treatment during this time.

By controlling the speed of the hot water flow, the degree of heat treatment of the tea leaves can also be controlled.

At this time, the flow path was formed in a substantially oval shape, going around the outer periphery and then around the inner periphery, which minimized sharp bending curves and minimized stagnation of tea leaves. can last for a long time.

In addition, as the end of the flow path is located approximately in the center of the hot water tank, it is now possible to install the belt conveyor in the center of the machine, making it easier to connect the front and rear equipment, the right machine, and the left machine. There is no need to distinguish between

In addition, the communication pipe 16, which is the return path of the flow path, is connected to the hot water tank 3.
Since it is arranged downward, it can be constructed compactly, and the screw 1 is installed in the hanging part 16a of the communication pipe 16.
9 is built-in, and the rotation is transmitted when its shaft 19a protrudes vertically upward from the water.
There is no need for a special sealing member for the shaft 19a, and the motor 18 and the like can be installed in the machine frame 2 in a compact manner. In addition, less power is required.

On the other hand, when the hot water becomes contaminated with sand and mud and tea leaf exudate, the sand and mud sink into the hot water but gradually move downstream, fall into the sand and mud settling groove 10 in the middle of the flow path, and overflow. When the sand and mud discharge valve 13 provided in the water pipe 11 is opened, the sand and mud are discharged to the outside of the tank. Additionally, the drain tank 17 and the like are opened to replace all the hot water in the hot water tank in a timely manner.

In addition, the amount of hot water in the hot water tank 3 decreases as the steamed tea leaves are scooped out on the belt conveyor, but the amount increases due to water replenishment and steam condensation in the hot water, resulting in excess and dirty boiling water. The water overflows from the tip 11a of the overflow pipe 11, and the water level inside the hot water tank 3 is maintained at a constant level.

At this time, the overflowing hot water is the hot water that has passed through the sand and mud sedimentation groove 10 and flowed down the bottom, so that the dirty hot water is sequentially discharged.

Next, the supplementary water supply system 6 will be explained.

First, open the main tap of the water supply, and when enough water has accumulated in the second filtration tank 37 by the action of the automatic water supply device 42, drive the water supply pump 39, and the water accumulated in the second filtration tank 37 will be discharged. The tea leaves are sent to the water sprinkling pipe 31, spouted in the form of a fountain from each water sprinkling port 32, and sprinkled onto the belt conveyor 4. If the tea leaves that have finished heat treatment are being moved here, the tea leaves are finished washed and quickly cooled down.

At this time, the water sprayed from the water spout located inside the hot water tank 3 mixes into the hot water tank 3 as it is.
Used as make-up water in the hot water tank. In other words, a portion of the finishing water is directly supplied to the hot water tank 3 as supplementary water.

On the other hand, the water sprayed by the belt conveyor portion projecting to the outside of the hot water tank 3 passes through the net belt and is collected from the falling water collection chute 34 below, through the induction chute 35, and into the first filtration tank 36.

When the water collected in the first filtration tank 36 accumulates to the position of the supernatant extraction port 38 opened in the tank, only the upper supernatant water overflows from the port 38 and flows into the second filtration tank 37. and move.

As mentioned above, the second filtration tank 37 is automatically replenished from the water pipe 41 by the automatic water supply device 42 to keep the water level in the tank constant. It is also replenished by The water here is then supplied to the water sprinkling pipe 31 again.

Therefore, this replenishment water supply system 6 replenishes the water that has already been consumed for finishing cooling, which is also the most contaminated water, for heat treatment in the hot water tank 3 on the other hand, and supplies it for other finishing cooling. The consumed water is collected, filtered, and then used again for final cooling, making it possible to use water efficiently and conserving water.

Note that the water sprinkling pipe 31 does not necessarily need to be used unless the tea leaves are very dirty with sand, mud, dust, and ash.
It can be cooled and removed using a so-called cooling machine or processing machine.

Furthermore, since the purpose of the method of the present invention is not only to save water, it is of course not necessary to carry out collection and filtration in this manner.

Next, the air supply system 7 will be explained.

The air pumped by the air pump 23 is guided to the air guide pipe 21 and ejected as bubbles from each jet port 22 in the hot water, thereby stirring the hot water in the hot water tank 3. This also eliminates temperature deviation in the depth direction of the hot water.

At this time, the hot water near the starting end of the flow path where the delivery end of the leaf feeder 43 faces is particularly vigorously stirred by the many blowholes.

On the other hand, the pressurized air branched from the air pump 23 is strongly blown through the blow pipe 26 in the tip turning section of the belt conveyor 4 so as to pass through the conveyor belt.

Next, the effects that the tea leaves undergo during the period from when the fresh tea leaves are dropped into the hot water tank 3 until when they are dropped into the dehydrator 45 will be mainly explained.

The green tea leaves dropped into the hot water tank 3 from the leaf feeder 43 are immediately immersed in the hot water due to agitation by air bubbles, and repeatedly float and sink.

Normally, if you simply drop green tea leaves, they will float. Furthermore, even if the agitation is weak, it cannot keep up with the feeding capacity of the leaf feeder, and floating green tea leaves gradually accumulate. For this reason, it is advisable to make the agitation by air bubbles especially vigorous near the area where it is dropped.

Here, stirring of the tea leaves is mainly caused by air bubbles coming from the air guide pipe 21, but if the hot water is in a boiling state, the steam bubbles coming from the steam pipe 29 are also extremely important, and this is the only way to use the tea leaves. In other words, the air guide pipe 21 can also be omitted.

In the case of this embodiment, the tea leaves being stirred by air bubbles are driven by the screw 19, and while repeating up and down movements of floating and sinking in the hot water, the tea leaves are left to the flow of the hot water and head downstream. undergoes heat treatment. At the same time, sand and mud adhering to the tea leaves are also washed away by contact between the tea leaves and collision with hot water and air bubbles. Furthermore, since the hot water in the hot water tank 3 is always flowing, temperature deviation within the hot water tank is completely eliminated, and the tea leaves are also sufficiently stirred, so that uneven heat treatment is less likely to occur.

The tea leaves that have reached the downstream flow are further directed to the part of the belt conveyor 4 that is floating out of the hot water, and as soon as the part immersed in the hot water comes into contact with the conveyor belt, the belt conveyor 4 moves the tea leaves to the part that is floating in the boiling water. It is scooped out of the boiling water in tank 3.

During the transfer, the tea leaves that have ascended on the belt conveyor 4 are cooled by receiving water from the sprinkling pipe 31 that is much cleaner than the hot water used for heat treatment up to now. At the same time, dirty adhering water etc. are also washed away. Then, it is directly dumped from the delivery end of the belt conveyor 4 to the feeder 46, where it is accumulated until a predetermined amount is reached, and then dumped all at once into the dewatering tank of the dehydrator 45.

When the tea leaves that are not completely dropped at the tip of the belt conveyor 4 and remain attached to the conveyor belt reach the return surface of the conveyor, they are thrown by the pressure air from the blowhole 25 into the feeding machine 46.
As it is blown upward, the net conveyor belt itself is also soaked.

Note that as the leaf feeder 43 and the dehydrator 45 installed before and after the green tea leaf heat treatment device 1, conventional devices that have been widely known may be used. In this case, it is not necessary to use a loading device 46 having a pool function, but in the case of a batch type, it is necessary to use a loading device 49 for temporary storage.

In addition, in this embodiment, as a hot water heating device, a steam pipe 29 is submerged in the hot water tank 3, and this and the boiler 3 are
Since we decided to install a boiler 30 in order to insulate and heat the hot water with steam, it is necessary to install a boiler 30, but the boiler itself can be an existing one. It can also be used as a simple washing machine, so the boiler can be shared.
It can also be used in conjunction with a traditional steamer, just as a different machine is used for each tea season.

〔Effect of the invention〕

As described above, the method of the present invention creates a stream-like flow of hot water in a flow path formed in a hot water tank, generates air bubbles in this flow, and the air bubbles move the green tea leaves dropped into the hot water upstream. This is a heat treatment method for green tea leaves that allows the flow of hot water to flow downstream while stirring up and down, and at the downstream, it is scooped up by a belt conveyor and taken out from the hot water. This eliminates the temperature deviation and insufficient stirring of tea leaves, allowing for even heat treatment while retaining the benefits of hot water treatment.

Furthermore, in the device of the present invention, a partition wall is provided in a hot water tank covered with a heat insulating material to form a flow path, an air guide pipe with a large number of blowholes is submerged in the flow path, and the end of the flow path is submerged. A discharge port is opened, and the starting end of a belt conveyor that slopes upward and projects out of the water tank is installed so that the part slightly ahead of the starting end is immersed in hot water to cover the discharge port, and an air guide pipe and an air pump are installed. This is a green tea leaf heat treatment device which is equipped with piping, a return flow path from the discharge port is connected to the starting end of the flow path, and a hot water flow starting device and a hot water heating device are attached to the flow path. There is no need for special mechanical members for this purpose, and the device can be made compact and easy to clean.

[Brief explanation of drawings]

FIG. 1 is a side view of a green tea leaf heat treatment apparatus according to an embodiment of the present invention equipped with front and rear equipment, and FIG. 2 is a plan view thereof. 1...Tea leaf heat treatment device, 2...Machine frame, 3...Hot water tank, 4...Belt conveyor, 9...Shipping wall, 14...Water opening, 15...Discharge port, 16...Communication pipe, 16a...Drooping part, 19 Screw , 21...Air guide pipe, 22...Full port, 23...Air pump, 28...Blowout port, 29...Steam pipe, 30...Boiler.

Claims (1)

[Scope of Claims] 1. A stream-like flow of hot water is created in a flow path formed in a hot water tank, and air bubbles are generated in this flow, and the air bubbles cause green tea leaves dropped into the hot water to float up and settle. While stirring, let the flow of hot water flow downstream.
In this method, green tea leaves are scooped up downstream using a belt conveyor and removed from boiling water. 2 A partition wall is provided in a hot water tank covered with heat insulating material to form a flow path, an air guide pipe with a number of blowholes is submerged in the flow path, and a discharge port is opened at the end of the flow path. The starting end of the belt conveyor, which slopes upward and protrudes out of the water tank, is installed so that the part slightly ahead of the starting end is immersed in hot water to cover the outlet, and an air guide pipe and an air pump are installed to create a flow path. A green tea leaf heat treatment apparatus, in which a return flow path from the discharge port is connected to the starting end, and a hot water flow starting device and a hot water heating device are attached to the flow path. 3. The green tea leaf heat treatment apparatus according to claim 2, wherein the belt conveyor is a net belt conveyor in which the belt itself is air permeable. 4. Claim No. 4, characterized in that when a partition wall is provided in a boiling water tank to form a flow path, the partition wall is provided in a substantially J-shape so as to form a flow path in a substantially square shape when viewed from above. The green tea leaf heat treatment apparatus according to item 2. 5 Open a water outlet at the bottom of the starting end of the flow path, connect the discharge port and the water flow mouth with a U-shaped communicating pipe below the hot water tank to form a return flow path, and connect the outlet to the water outlet at the hanging part on the water outlet side of the communication pipe. The green tea leaf heat treatment apparatus according to claim 2, characterized in that a screw is installed therein as a hot water flow starting device. 6. The green tea leaf heat treatment according to claim 2, characterized in that a steam pipe with a large number of spouts is sunk in a flow path, and the steam pipe and a boiler are connected to form a hot water heating device. Device. 7. The green tea leaf heat treatment device according to claim 2, characterized in that the hot water heating device heats a part of the bottom of the hot water tank with the combustion flame of a burner.