JP2010017140A - Method for parching tea leaf, system for producing unrefined tea and method for producing unrefined tea - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for parching tea leaves by which the improvement of the quality of unrefined tea and the reduction of the production cost can be achieved by shortening the steaming time of the tea leaves by using superheated steam. <P>SOLUTION: The system 100 for producing unrefined tea includes a tea leaf-cutter 20 for cutting pruned tea leaves, and a steaming machine 30 for carrying out the parching treatment of the tea leaves by heating the tea leaves with steam. The tea leaf-cutter 20 has two mutually parallelly arranging shafts 23a and 23b equipped with a plurality of disk-shaped rotary blades 22 in a housing 21, and cuts the tea leaves inserted into the housing 21 to about 20 mm width. The steaming machine 30 is equipped with a steam-forming device 43 and a heater 46 for forming steam having about 300&deg;C temperature, and a heat treating part 36 for carrying out the heat treatment of the tea leaves by using the formed steam. The unrefined tea-producing system 100 cuts the tea leaves, and parches the cut tea leaves by the steaming machine 30 by heating the tea leaves for 40 sec only by using the steam heated to about 300&deg;C by means of the steaming machine 30. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a tea leaf blue-killing method for killing tea leaves to produce crude tea from tea leaves plucked from a tea plantation, a crude tea production system using the tea leaf blue-killing method, and the tea The present invention relates to a method for producing crude tea using the method of killing leaves.

  In general, tea leaves plucked from a tea garden are processed into finished tea (product tea) through rough tea. Crude tea is produced by steaming the picked tea leaves with steam to stop the action of the oxidase, and then undergoing various brewing processes (coarse, memorial, medium and refined) and drying processes. The produced crude tea is finally processed into finished tea through further steps such as sieving, drying, foreign matter removal, and homogenization. That is, rough tea is tea leaves that have not been refined and are temporarily processed. Among the processing steps to produce this crude tea, the so-called blue-killing treatment (also called “steaming heat treatment”) determines the color and flavor of tea to be drunk, by steaming tea leaves to stop the action of oxidase. This is one of the important processing steps. Conventionally, the tea leaves are subjected to blue-killing treatment by bringing steam (water vapor) having a temperature of around 100 ° C. into contact with the picked tea leaves, so-called fresh leaves, for 30 to 200 seconds.

By the way, recently, for example, as shown in Patent Document 1 below, steam of 100 ° C. or higher, specifically 200 to 400 ° C., is used for the purpose of quickly deactivating oxidase contained in tea leaves. The tea leaves are treated with superheated steam.
JP 2007-45 A

  However, in the tea leaf detoxification treatment using such superheated steam, if the time for which the tea leaves are in contact with the steam, that is, the steaming time is increased, the color change of the tea leaves and the effectiveness contained in the tea leaves The quality of the raw tea is significantly reduced due to the deterioration of ingredients. Moreover, since much energy is required for the production | generation of superheated steam and temperature maintenance, the manufacturing cost of crude tea will increase if steaming time becomes long. Therefore, it is required that the tea leaf blue-killing process using superheated steam be performed in a shorter time than the normal blue-killing process using steam at around 100 ° C.

  In particular, tea leaves picked after summer, that is, tea leaves used for bancha, have larger tea leaves and thicker than the first tea (new tea) picked in spring. For this reason, shortening the steaming time is extremely important in the tea leaf detoxification treatment using superheated steam for bancha.

  The present invention was made to address the above problems, and its purpose is to improve the quality of crude tea and reduce manufacturing costs by shortening the steaming time of tea leaves using superheated steam. It is intended to provide a method for killing tea leaves, a system for producing crude tea using the tea leaf killing method, and a method for producing crude tea using the tea leaf killing method.

  In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that, in the tea leaf blue-killing method for killing the picked tea leaves using steam, a cutting step for cutting the picked tea leaves, and a temperature A high temperature steam generation step for generating steam at a temperature of 200 ° C. or higher and 450 ° C. or lower, and a tea leaf heating step for heating and killing the cut tea leaves using only the steam generated in the high temperature steam generation step, It is to include.

  In this case, in the tea leaf blueing method, the cutting step may be performed by cutting the picked tea leaves with a width of 3 mm or more and within 30 mm. In the tea leaf heating step, the tea leaves may be heated in an atmosphere having a humidity of 90% or more for 5 seconds to 110 seconds.

  According to the feature of the invention according to claim 1 configured as described above, tea leaves (so-called fresh leaves) plucked from the tea garden are cut into an appropriate size and heated only by steam in a temperature range of 200 to 450 ° C. Then, the killing process is performed. That is, since the tea leaf size to be treated is reduced and the surface area is increased, the tea leaf is heated more instantaneously and subjected to the blue killing treatment. Thereby, discoloration of the tea leaf color and alteration of the active ingredient contained in the tea leaf can be suppressed, and the amount of superheated steam necessary for the tea leaf blue-killing treatment can be reduced. As a result, the quality of the crude tea can be improved and the production cost of the crude tea can be reduced. In particular, the effect of improving the quality of crude tea and reducing the manufacturing cost with respect to the bancha is significant.

  According to a fourth aspect of the invention, in the tea leaf blue-killing method, the tea leaf heating step is to heat the picked tea leaves while stirring them. According to the characteristic of the invention which concerns on Claim 4 comprised in this way, the tea leaf which is a process target contacts high temperature steam, stirring. As a result, the tea leaves in the tea leaf heating process can be heated uniformly and evenly in a shorter time to perform a blue killing treatment.

  The invention according to claim 5 is characterized in that it further includes a drying step of drying the plucked tea leaves so that the moisture content is 300% or less on a dry basis. According to the characteristic of the invention which concerns on Claim 5 comprised in this way, the tea leaf is dried and the water content is made into 300% or less prior to the blue-killing process of a tea leaf. For this reason, it is possible to prevent a temperature drop in the steamer when the tea leaves are put into a steaming machine for killing tea leaves, and to improve the heating efficiency of the tea leaves. As a result, tea leaves can be killed with higher accuracy in a shorter time, and high-quality crude tea can be produced.

  In addition, in the conventional tea making method for green tea, tea leaves picked from the tea garden are quickly killed in a fresh state with a lot of moisture (the moisture content of fresh leaves is 350-600%). It was requested to be offered to. However, in the tea leaf killing method according to the present invention, a tea leaf treatment is performed on a tea leaf having a low moisture content, which has been considered to be unfavorable in the past. Even tea leaves having a reduced water content can be treated with high accuracy and can produce high quality crude tea.

  Moreover, the said drying process also includes the process which wilts the picked tea leaf. Therefore, according to the method for killing tea leaves according to the present invention, it is possible to accurately kill tea leaves that have been wilted to reduce the water content, and at the same time, a unique flavor by wiping tea leaves ( It is possible to accurately produce rough tea that also exhibits wilt.

  In addition, the present invention can be implemented not only as a tea leaf killing method, but also as a crude tea production system using the same killing method and a method for producing crude tea for producing crude tea from the picked tea leaves. Can also be implemented.

  Hereinafter, an embodiment of a crude tea production system using the tea leaf killing method according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram schematically showing a part of the configuration of a crude tea production system 100 for producing crude tea by applying the tea leaf blue-killing method according to the present invention. Note that each drawing referred to in the present specification is schematically represented by exaggerating some of the components in order to facilitate understanding of the present invention. For this reason, the dimension, ratio, etc. between each component may differ.

(Configuration of rough tea production system 100)
The crude tea production system 100 is constituted by various tea making machines for producing so-called crude tea from tea leaves plucked from a tea garden. Specifically, it includes a fixed-number leaf conveyor 10, a tea leaf cutting machine 20, a steamer 30, and a fixed-number leaf conveyor 60. Here, as described above, the rough tea is a tea leaf in an unpurified primary state in which plucked tea leaves are subjected to a blue kill treatment and dried.

  The fixed leaf feeder 10 is a transport device that receives tea leaves processed by the rough tea manufacturing system 100 and transports the tea leaves to the tea leaf cutting machine 20 every predetermined amount, and its operation is controlled by a control device (not shown). The constant-rate feed conveyor 10 includes a feed opening 11 that opens near the floor on which the fixed-rate feed conveyor 10 is installed, and an endless belt conveyor that conveys tea leaves that are input into the feed opening 11 obliquely upward. It is comprised from the conveyance body 12 provided with (not shown) and the discharge port 13 which discharge | releases the tea leaf conveyed by the endless belt toward the downward direction. Among these, a plurality of plate-like bars (not shown) are provided on the endless conveyor provided in the transport body 12 at regular intervals in a state of protruding from the endless conveyor, and are input to the leaf feeder 11. The tea leaves can be transported at regular intervals. A tea leaf cutting machine 20 is disposed below the discharge port 13 of the fixed-number feed conveyor 10.

  As shown in detail in FIG. 2, the tea leaf cutting machine 20 is configured by arranging two shafts 23 a and 23 b provided with a plurality of disk-shaped rotary blades 22 in parallel in a box-shaped housing 21. . Each rotary blade 22 in each shaft 23a, 23b is for cutting the tea leaves put into the tea leaf cutting machine 20, and two rotations of the other shafts 23b, 23a arranged to face each other. Each is disposed between the blades 22. In this embodiment, the input tea leaves are cut into a width of about 20 mm. One end (the lower side in the drawing) of the shafts 23a and 23b is rotatably supported on the side wall of the housing 21 via a bearing 24a. The other end (the upper side in the figure) of the shafts 23a and 23b is supported in a freely rotatable state via a bearing 24b in a state where the side wall is opposed to the side wall that supports the one end and penetrates the side wall. ing.

  An electric motor 27 is connected to the other end of the shafts 23 a and 23 b penetrating the side wall of the housing 21 via disk-like pulleys 25 a and 25 b and a V-belt 26. The electric motor 27 is a drive source for rotating and driving the shafts 23 a and 23 b, and is arranged and fixed outside the housing 21. In the upper part of the casing 21 above the shafts 23a and 23b, an introduction port 28 for receiving tea leaves put into the casing 21 is provided. A discharge port 29 for discharging the tea leaves cut by the rotary blade 22 from the inside of the housing 21 is provided at the bottom of the housing 21 below the shafts 22a and 22b. Note that, in FIG. 1, a part of the side surface of the housing 21 is cut away to show the inside of the housing 21. In FIG. 2, the introduction port 28 is omitted to show the inside of the housing 21.

  A steamer 30 is disposed below the discharge port 28 in the tea leaf cutting machine 20. The steamer 30 is a device that performs so-called blue-killing treatment that stops the action of the oxidase contained in tea leaves by applying heat to the picked tea leaves. As shown in FIG. A heat treatment unit 36 including an outer cylinder 32, a net body 43, a drive gear 34, and a conveyance shaft 35 is provided. The introduction body 31 is a member that introduces tea leaves plucked from the tea garden and steam for heating the tea leaves into the heat treatment unit 36, and a cylindrical body made of stainless steel is formed in a substantially L shape. It is configured in combination.

  Specifically, the introduction body 31 has one end portion of a cylindrical body formed in an approximately L shape opening toward the upper side in the drawing, and the other end portion (right side in the drawing) opening toward the right side in the drawing. Is formed. A discharge port 28 (shown by a two-dot chain line) of the tea leaf cutting machine 20 is connected to an input port 31 a that opens upward in the drawing of the introduction body 31. A steam supply hole 31b penetrating from the upper part of the outer peripheral surface to the inner peripheral surface of the introduction body 31 is formed in the upper part of the outer peripheral surface extending in the horizontal direction in the introduction body 31. The steam supply hole 31b is a hole for introducing steam into the introduction body 31, and one end of a steam supply pipe 51 to be described later is connected thereto.

  An outer cylinder 32 is connected to the other end of the introduction body 31 via a drive gear 34. The outer cylinder 32 is a member for heating and killing the tea leaves introduced into the heat treatment unit 36 by using steam introduced into the heat treatment unit 36, and a stainless steel material is formed in a cylindrical shape. Configured. Inside the outer cylinder 32 is provided a net cylinder 33 in which a net body made of stainless steel is formed in a cylindrical shape. The net barrel 33 is a member for holding the tea leaves to be processed in the outer cylinder 32, and one end (the left side in the figure) has one end (the left side in the figure) of the outer cylinder 32 via the drive gear 34. The other end (the right side in the figure) is supported by the other end (the right side in the figure) via the bearing 37 so that the other end (the right side in the figure) can rotate. Has been. In other words, the net barrel 33 is supported in a rotatable state within the outer cylinder 32. The mesh size of the net barrel 33 is smaller than the size of the tea leaves cut by the tea leaf cutting machine 20.

  The drive gear 34 is a gear member formed in a cylindrical shape, and an external gear is formed at one end (the left side in the drawing) of the outer peripheral surface, and the other end (the right side in the drawing) of the outer peripheral surface is formed. The outer cylinder 32 is fitted into an inner peripheral surface of one end (left side in the drawing) in a rotatable state via a bearing (not shown). Further, the outer peripheral surface of one end (the left side in the figure) of the mesh body 33 is fitted in the inner peripheral surface of one end (the right side in the figure) of the drive gear 34 in a state where it can be attached and detached and cannot be relatively rotated. . That is, the drive gear 34 and the net cylinder 33 are assembled so as to rotate integrally. Furthermore, the other end (right side in the figure) of the introduction body 31 is fitted in the inner peripheral surface of the other end (left side in the figure) of the drive gear 34 through a bearing (not shown) in a rotatable state. The drive gear 34 is rotationally driven by an electric motor 34a.

  Inside the introduction body 31 and the inside of the outer cylinder 32, a conveyance shaft 35 is provided so as to penetrate the introduction body 31 and the outer cylinder 32 in the longitudinal direction. The transport shaft 35 is a member for transporting the tea leaves in the introduction body 31 and the net body 33 while stirring. A pulley 35a and a plurality of transport blades 35b are provided on the outer peripheral surface of a rod made of stainless steel. It is prepared for. The pulley 35a is a power transmission member formed in a disk shape that transmits the rotational driving force of the electric motor 35c to the conveyance shaft 35 via a belt (not shown), and is provided at one end (left side in the drawing) of the conveyance shaft 35. It is fixedly assembled.

  The conveyance blade 35 b is a plate material made of a stainless material formed in a rectangular shape having a long side corresponding to each inner diameter of the introduction body 31 and the net body 33, and is 90 in the circumferential direction on the outer circumferential surface of the conveyance shaft 35. They are shifted by a certain degree and are provided at predetermined intervals in the axial direction. Note that the interval at which the conveying blades 35 b are formed in the introduction body 31 is narrower than the interval at which the conveying blades 35 b are formed in the net body 33. The transport shaft 35 is supported in a state where both ends thereof are freely rotatable on a support base 50 shown only in a part of the drawing, and is rotated by an electric motor 35c through a pulley 35a.

  The heat treatment unit 36 configured as described above is fixed on the support base 50 in a state where the discharge port 33a side of the net barrel 33 from which the tea leaves are discharged is inclined downward (not shown). ). Moreover, this heat processing part 36 is corresponded to the tea leaf heating means which concerns on this invention.

  The steam supply pipe 41 connected to the introduction body 31 is a pipe for introducing steam into the introduction body 31, and one end (the left side in the figure), that is, the discharge port 42 through which the steam is discharged is the introduction body. 31 is provided in an open state. The discharge port 42 in the steam supply pipe 41 is formed in a so-called trumpet shape in which the inner diameter gradually increases toward the tip, and is formed so that the discharged steam spreads over a wide range.

  A steam generating furnace 43 is connected to the other end (right side in the figure) of the steam supply pipe 41. The steam generation furnace 43 is a boiler device that generates steam to be supplied into the introduction body 3, and includes a water storage tank 44 that stores water and a heating unit 45 that heats the water stored in the water storage tank 44. Yes. Among these, a water absorption tank (not shown) is connected to the water storage tank 44 through a water supply pipe 44 a so that a constant amount of water is always stored in the water storage tank 44. Further, the steam supply pipe 41 is connected to the upper end portion of the water storage tank 44 so that the steam generated in the water storage tank 44 is guided to the steam supply pipe 41. On the other hand, the heating unit 45 is a gas burner for heating the water stored in the water storage tank 44 to generate steam (water vapor), and is disposed below the water storage tank 44.

  A heating device 46 is provided in the steam supply pipe 41 between the steam generating furnace 43 and the introduction body 31. The heating device 46 is an electric heating coil that can heat the steam flowing in the steam supply pipe 41 in a temperature range of 200 ° C. to 450 ° C., and is provided in a state of being wound around the outer peripheral surface of the steam supply pipe 41. Yes. These steam generating furnace 43 and heating device 46 correspond to the high temperature steam generating means according to the present invention. In the heating device 46, the heat source for heating the steam supply pipe 41 may naturally be a heat source other than the electric heating coil (for example, a gas burner). In addition, a manual valve 47 is provided in the steam supply pipe 41 between the heating device 46 and the introduction body 31. The manual valve 47 is a valve for adjusting the flow rate of the steam flowing through the steam supply pipe 41, that is, the amount of steam guided into the introduction body 31.

  Below the discharge port 33 a of the steamer 30, a leaf feed port 61 of the leaf feed conveyor 60 is disposed. The leaf feeder conveyor 60 is a transport device for transporting tea leaves discharged from the steamer 30 to another tea machine (indicated by a two-dot chain line) (for example, a cooler). The same feed opening 61, the conveyance body 62, and the discharge opening 63 are provided.

  The crude tea production system 100 includes a cooling machine that cools tea leaves processed by the steamer 30 in addition to the above-described fixed-quantity feeding conveyor 10, the tea leaf cutting machine 20, the steamer 30, and the fixed-quantity feeding conveyor 60. There are provided various tea making machines such as a roughing machine and a twisting machine for holding tea leaves cooled by a cooling machine, and various tea making machines (all not shown) such as a drying machine for drying the tea leaves. However, since these various tea machines are not directly related to the present invention, the description thereof is omitted.

(Operation of rough tea production system 100)
Next, the operation of the crude tea manufacturing system 100 configured as described above will be described. First, the operator turns on each tea machine including the tea leaf cutting machine 20 and the steamer 30 by turning on a power switch (not shown) in each tea machine. Next, the operator sets the operating conditions of each tea machine for each tea machine. In this case, the operator operates an operator (not shown) in the tea leaf dryer 20 to set the number of rotations of the shafts 23a and 23b according to the insertion of tea leaves.

  In addition, the operator operates an operation element (not shown) in the steamer 30 to operate the steamer 30, specifically, the temperature of the steam introduced into the introduction body 31, the time for processing the tea leaves, and the net barrel 33. Set the number of rotations for each. In this embodiment, the temperature of the steam introduced into the introduction body 31 is 300 ° C. as the operating condition of tea leaves picked after summer, that is, tea leaves drunk as so-called bancha, and the time for processing the tea leaves Is 40 seconds. In addition, although an operator also sets each operating condition in the other tea machine which comprises a tea-making line, since each of these operating conditions is not directly related to this invention, the description is abbreviate | omitted.

  Next, the operator operates each operator in each tea machine including the tea leaf cutting machine 20 and the steamer 30 to start the operation of each tea machine. Thereby, the tea leaf cutting machine 20 starts rotation drive of the shafts 23a and 23b. On the other hand, about 300 ° C. steam generated by the start of the operation of the steam generation furnace 43 and the heating device 46 is continuously supplied into the heat treatment unit 36 in the steamer 30 via the steam supply pipe 41. The superheated steam supplied into the heat treatment section 36 is quickly and widely guided toward the bottom in the introduction body 31 and also flows in the outer cylinder 32 disposed adjacent to the introduction body 31. . Thereby, the inside of the introduction body 31 and the outer cylinder 32 around the discharge port 42 of the steam supply pipe 41 becomes an atmosphere in which the humidity due to the supplied steam is nearly 100%.

  The operator operates the manual valve 47 of the steam supply pipe 41 to change the flow rate of the steam supplied into the introduction body 31 to the state of the tea leaf to be processed, the weather conditions of the day on which the rough tea is manufactured, or the like. Adjust accordingly. In addition, the steamer 30 starts the operation of the electric motors 34a and 35c, thereby rotating the net barrel 33 and the conveying shaft 35 at the rotation speed corresponding to the set tea leaf processing time.

  When each tea making machine including the tea leaf cutting machine 20 and the steamer 30 becomes ready to accept tea leaves, the worker removes the tea leaves (fresh leaves) that have been plucked from the tea garden and cleaned and foreign substances removed. The tea leaves are fed into the feed opening 11 of the fixed-quantity leaf conveyor 10 and tea leaf processing, that is, production of crude tea is started. Thereby, the tea leaves plucked from the tea garden are continuously supplied into the casing 21 of the tea leaf cutting machine 20 through the introduction port 28. The tea leaves supplied into the casing 21 of the tea leaf cutting machine 20 are continuously cut to a width of about 20 mm by the rotary blade 22 that is driven to rotate and discharged from the discharge port 29.

  The tea leaves discharged from the discharge port 29 of the tea leaf cutting machine 20 are put into the introduction body 31 of the steamer 30. The tea leaves thrown into the introduction body 31 are conveyed toward the outer cylinder 32 through the introduction body 31 by the rotational drive of the conveyance shaft 35. As described above, steam having a temperature of about 300 ° C. is continuously supplied into the introduction body 31 from the discharge port 42 of the steam supply pipe 41. Accordingly, the tea leaves introduced into the introduction body 31 are rapidly heated in contact with the high-temperature steam supplied into the introduction body 31. In this case, the conveyance blade 35 b provided on the outer peripheral surface of the conveyance shaft 35 rotates with the conveyance shaft 35. Further, the tea leaves put into the introduction body 31 are cut by the tea leaf cutting machine 20 with a width of about 20 mm. As a result, the tea leaves introduced into the introduction body 31 are conveyed to the net cylinder 33 in the outer cylinder 32 while being heated rapidly and uniformly.

  As described above, high-temperature steam is guided from the introduction body 31 into the outer cylinder 32, and the tea leaves in the introduction body 31 are conveyed into the net cylinder 33 in the outer cylinder 32. Therefore, the tea leaf guided into the outer cylinder 32 is continuously heated by the steam guided into the outer cylinder 32 and is stirred by the rotational drive of the stirring blade 35b and the net cylinder 33 while the other of the net cylinder 33 is being stirred. It is conveyed toward the end of the. The tea leaves are subjected to blue-killing treatment by heat treatment in the introduction body 31 and the outer cylinder 32. In this case, the tea leaves guided to the entrance side (the left end portion in the figure) of the net barrel 33 are multiplied by the set tea leaf processing time (in this embodiment, 40 seconds). It is conveyed toward the discharge port 33a. That is, the tea leaves put into the heat treatment unit 36 are heated during the set tea leaf treatment time and subjected to a blue-killing treatment. While confirming the state of the tea leaves subjected to the blue-killing treatment, the worker confirms the amount of tea leaves to be introduced into the heat treatment unit 36, the processing time of the tea leaves, and the heat treatment unit 36 (introduction body 31). ) Adjust the temperature, flow rate, etc. of the steam supplied inside.

  Then, the tea leaves that have been subjected to the blue-killing process are discharged from the discharge port 33a of the net barrel 33 into the leaf supply port 61 of the fixed-quantity feed conveyor 60. The tea leaves discharged to the leaf feeder 61 of the fixed leaf conveyor 60 are transferred to other tea making machines (for example, a cooler, various roughing machines, and dryers) that constitute the crude tea production system 100 by the transport body 62. It is supplied, processed, and finally processed into crude tea. According to the present inventor, the crude tea produced from tea leaves (bancha) treated with the above-mentioned operating conditions maintains the color of the tea leaves in green and does not become powdery. It was finished in rough tea with the same flavor.

  As can be understood from the above description of operation, according to the above embodiment, the tea leaves (so-called fresh leaves) picked from the tea garden are cut into a size of 200 mm in width and heated only by superheated steam at about 300 ° C. The blue killing process is performed. That is, since the tea leaf size to be treated is reduced and the surface area is increased, the tea leaf is heated more instantaneously and subjected to the blue killing treatment. Thereby, discoloration of the tea leaf color and alteration of the active ingredient contained in the tea leaf can be suppressed, and the amount of superheated steam necessary for the tea leaf blue-killing treatment can be reduced. As a result, the quality of the crude tea can be improved and the production cost of the crude tea can be reduced. In particular, the effect of improving the quality of crude tea and reducing the manufacturing cost with respect to the bancha is significant.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  For example, in the above-described embodiment, the tea leaves were subjected to a blue-killing treatment by supplying steam at a temperature of about 300 ° C. to the tea leaves and heating them for 40 seconds. However, the temperature of steam for killing tea leaves and the time for which the steam is brought into contact with the tea leaves depend on the state of the tea leaves to be processed (such as the thickness and hardness of the tea leaves) and the heat treatment unit 36. It is determined as appropriate according to the amount of tea leaves to be introduced, the weather conditions on the day of the blue-killing treatment, and the like, and is not limited to the above embodiment. In this case, according to an experiment by the present inventor, the temperature of the water vapor supplied to the tea leaves is preferably 200 ° C. or higher and 450 ° C. or lower, and the time for contacting the steam with the tea leaves is preferably 5 seconds or longer and 110 seconds or shorter. is there. In this case, the thicker and harder the tea leaves, the higher the temperature and the longer the steaming time is. In the present embodiment, the tea leaf to be processed is bancha, but the processing target is not limited to bancha. In other words, it is a matter of course that tea leaves picked around May, so-called new tea, may be treated. Also by these, the same effect as the above-mentioned embodiment can be expected.

  Moreover, in the said embodiment, the tea leaf plucked from the tea plantation was cut | disconnected by the width | variety of 20 mm with the tea leaf cutting machine 20. FIG. However, the width at which the tea leaves are cut depends on the state of the tea leaves to be processed (such as the thickness and hardness of the tea leaves), the amount of tea leaves to be put into the heat treatment unit 36, and the weather on the day of the blue-killing treatment. It is appropriately determined depending on conditions and the like, and is not limited to the above embodiment. In this case, according to an experiment by the present inventor, it is preferable to cut the tea leaves into a width of 3 to 30 mm. Further, the configuration of the tea leaf cutting machine 20 that cuts tea leaves is not limited to the above embodiment, and any configuration that can cut tea leaves into a desired size may be used.

  Furthermore, in the above embodiment, the bancha is the tea leaf to be processed, but the tea leaf processed using the present invention is not limited to this. That is, tea leaves other than bancha, specifically, tea leaves picked around May, so-called new tea or tea leaves picked after new tea or the like may be treated. Also by these, the same effect as the above-mentioned embodiment can be expected.

  Moreover, in the said embodiment, it comprised so that the tea leaf thrown in in the outer cylinder 32 might be stirred by arrange | positioning the net drum 33 which rotates in the outer cylinder 32. FIG. This is because by rotating the net barrel 33 and stirring the tea leaves, the steam is brought into uniform contact with the tea leaves in a short time without unevenness. Therefore, it is not always necessary to agitate the tea leaves as long as the high temperature steam is in contact with the tea leaves put into the heat treatment unit 36. That is, it is not always necessary to rotationally drive the net cylinder 33. Further, it is not necessary to convey the tea leaves while stirring them by the conveying shaft 35. For example, tea leaves are placed on an endless belt-shaped net conveyor that is smaller than the size of the cut tea leaves, and hot steam is brought into contact with tea leaves that are stationary on the net conveyor. Alternatively, the tea leaves may be put into a hermetically sealed pot-shaped container and steam may be supplied into the container to perform a blue-killing treatment. Also by these, the same effect as the above-mentioned embodiment can be expected.

  Moreover, in the said embodiment, although the tea leaf plucked from the tea garden was cut | disconnected and put into the steamer 30, you may dry a tea leaf to some extent before putting into the steamer 30. FIG. That is, in the crude tea production system 100, a tea leaf dryer for drying tea leaves plucked from the tea garden is installed in the pre-process of the steamer 30. In this case, it is appropriate for the tea leaf dryer to dry the moisture content of tea leaves plucked from the tea garden to about 300% or less on a dry basis. According to this, it is possible to prevent a temperature drop in the steamer 30 when the tea leaves are put into the steamer 30 for performing the killing treatment of the tea leaves, and the heating efficiency of the tea leaves put into the steamer is improved. As a result, tea leaves can be killed with higher accuracy in a shorter time, and high-quality crude tea can be produced.

  The tea leaf drying process may be performed before or after cutting the tea leaves. In this case, the tea leaf drying step may wilt the picked tea leaves. According to this, tea leaves that have been withered and whose moisture content has been reduced can be accurately killed, and at the same time, crude tea that has a unique flavor (wilt incense) due to wilt of tea leaves is accurately produced. can do.

  Moreover, in the said embodiment, it comprised so that the vapor | steam supply piping 41 might be connected in the introduction body 31, and a vapor | steam may be supplied. However, the position and number of the steam to be supplied into the heat treatment unit 36 are limited to the above embodiment as long as the steam can be uniformly contacted with the tea leaves put into the heat treatment unit 36 without unevenness. It is not a thing. For example, instead of or in addition to supplying steam to the introduction body 31, a steam supply pipe 41 may be connected to the outer cylinder 32 so as to supply steam directly into the outer cylinder 32. Two or more steams may be provided to the heat treatment unit 36. Furthermore, you may make it the structure which connected the several heat processing part 36 in series. According to these, it is possible to suppress the temperature drop of the steam during the tea leaf blue treatment, and to perform the tea leaf blue treatment, and the temperature and amount of the steam supplied to the tea leaf for each heat treatment unit 36. It is possible to perform fine blue killing treatment according to the state of tea leaves by adjusting.

  Moreover, in the said embodiment, the shape of the heat processing part 36 which performs a blue killing process of the tea leaf was formed in the substantially cylindrical shape by which the both ends of the outer cylinder 32 were open | released. However, the heat treatment unit 36 is not limited to the above-described embodiment as long as the heat treatment unit 36 can contact the tea leaves with high-temperature steam for a predetermined time. For example, it is good also as a structure which external air does not enter in the heat processing part 36 during the process of a tea leaf as a structure which can obstruct | occlude both ends of the introduction hole 31 and the outer cylinder 32. FIG. According to this, the inside of the processing chamber 31b can be maintained at a high temperature, and the intrusion of a gas other than steam can be prevented, so that the tea leaf can be treated with higher accuracy.

  Moreover, in the said embodiment, it comprised so that the vapor | steam discharged from the discharge port 42 of the vapor | steam supply piping 41 might directly contact with the tea leaf thrown in in the introduction body 31. FIG. This is because steam at a high temperature (about 300 ° C. in the present embodiment) is quickly supplied to the tea leaves to be treated. According to an experiment by the present inventor, in a state where the tea leaves are accommodated in a net barrel 33 or a so-called punching barrel in which a plurality of holes are formed in the outer peripheral surface of a stainless steel cylindrical body in the heat treatment unit 36, When steam was supplied from the outside of the net cylinder 33 or the punching cylinder, it was difficult for the steam to be guided to the net cylinder 33 or the punching cylinder, and the temperature of the introduced steam decreased. In particular, when the net cylinder 33 or the punching cylinder is driven to rotate, it is difficult for the steam to be guided to the net cylinder 33 or the punching cylinder, and the temperature of the introduced steam is significantly reduced.

  Therefore, in the case of the heat treatment unit 36 configured to supply steam to the tea leaves accommodated in the net cylinder 33 or the punching cylinder, the steam supplied in consideration of heat loss until reaching the tea leaves. It is necessary to set the temperature of the steam and increase the amount of steam supplied. In the above-described embodiment, the discharge port 42 of the steam supply pipe 41 is formed in a divergent trumpet shape, but it is not always necessary to have a trumpet shape, and the inner diameter of the discharge port 42 may be formed in a constant straight shape. Good. Moreover, it is good also as a structure which provides a punching plate in the opening part of the discharge outlet 42, and injects a vapor | steam. Also by these, the same effect as the above-mentioned embodiment can be expected.

  Moreover, in the said embodiment, the tea leaf was heated and the blue killing process was performed in the atmosphere where the humidity by the vapor | steam supplied by the vapor | steam supply piping 41 is substantially 100%. According to the experiment of the present inventor, it is preferable to heat the tea leaves in an atmosphere where the humidity due to the high-temperature steam supplied by the steam supply pipe 41 is approximately 90% or more to perform the blue killing treatment. However, the humidity of the atmosphere for heating the tea leaves is appropriately adjusted according to the state of the picked tea leaves (pickup season, leaf thickness, hardness, etc.), and the humidity is 90% or more. It is not meant to limit heating the tea leaves inside.

  Moreover, in the said embodiment, in order to suppress the heat loss of the vapor | steam supplied in the heat processing part 36, the structure which heat-retains the heat processing part 36 is not provided. However, it is a matter of course that a heat retaining member such as a heat insulating material may be provided on the outer peripheral portion of the heat treatment unit 36. Further, for example, the heat loss of the steam supplied into the heat treatment unit 36 can be suppressed by heating the outer cylinder 32 from the outside within a range where the tea leaves in the heat treatment unit 36 are not heated to the extent that they can be killed. Also good. Also by these, the same effect as the above-mentioned embodiment can be expected.

It is the structure schematic which showed the structure of a part of rough tea manufacturing system which applied the tea leaf blue-killing method which concerns on one Embodiment of this invention. It is a partially broken top view which shows typically the structure of the tea leaf cutting machine shown in FIG. It is a partially broken side view which shows typically the whole structure of the steamer shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fixed-quantity feeding conveyor, 20 ... Tea leaf cutting machine, 21 ... Housing | casing, 22 ... Rotary blade, 23a, 23b ... Shaft, 24a, 24b ... Bearing, 25a, 25b ... Pulley, 26 ... V belt, 27 ... Electric motor 28 ... introduction port, 29 ... discharge port, 30 ... steamer, 31 ... heat treatment unit, 31 ... introduction body, 32 ... outer cylinder, 33 ... net drum, 34 ... drive gear, 34a ... electric motor, 35 ... transport shaft 35a ... pulley, 35b ... conveying blade, 35c ... electric motor, 41 ... steam supply piping, 42 ... discharge port, 43 ... steam generator, 44 ... water tank, 45 ... heating unit, 46 ... heating device, 47 ... manual Valves, 50 ... support base, 60 ... quantitative feed conveyor.

Claims (9)

In the tea leaf killing method of killing tea leaves that have been plucked using steam,
A cutting step of cutting the picked tea leaves;
A high-temperature steam generating step for generating steam having a temperature of 200 ° C. or higher and 450 ° C. or lower;
And a tea leaf heating step for heating and killing the cut tea leaves using only steam generated in the high temperature steam generation step. The method for killing tea leaves according to claim 1,
The cutting step is a method of killing tea leaves by cutting the picked tea leaves with a width of 3 mm or more and 30 mm or less. In the method for killing tea leaves according to claim 1 or 2,
The tea leaf heating step is a method for killing tea leaves by heating the tea leaves for 5 seconds to 110 seconds in an atmosphere having a humidity of 90% or more. In the method for killing tea leaves according to any one of claims 1 to 3,
In the tea leaf heating step, the plucked tea leaves are heated while being stirred. In the method for killing tea leaves according to any one of claims 1 to 4,
A method for killing tea leaves, comprising a drying step of drying the plucked tea leaves to a water content of 300% or less on a dry weight basis. In the crude tea production system that produces crude tea from the picked tea leaves,
Cutting means for cutting the picked tea leaves;
High-temperature steam generating means for generating steam having a temperature of 200 ° C. or higher and 450 ° C. or lower;
And a tea leaf heating means for heating and drying the dried tea leaves in a range of not less than 5 seconds and not more than 110 seconds using only the steam generated by the high temperature steam generating means. Crude tea production system. In the rough tea manufacturing system according to claim 6, further,
A crude tea production system comprising drying means for drying the plucked tea leaves so that the moisture content is 300% or less on a dry basis. In the method for producing crude tea, which produces crude tea from the picked tea leaves,
A cutting step of cutting the picked tea leaves;
A high-temperature steam generating step for generating steam having a temperature of 200 ° C. or higher and 450 ° C. or lower;
And a tea leaf heating step of heating and drying the dried tea leaves in a range of 5 seconds to 110 seconds using only the steam generated in the high temperature steam generation step. A method for producing crude tea. The method for producing crude tea according to claim 8, further comprising:
A method for producing crude tea, comprising a drying step of drying the plucked tea leaves to a water content of 300% or less on a dry weight basis.

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