JP4573086B2 - Method and apparatus for steaming heat treatment of tea leaves - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a tea leaf steaming method and apparatus for steaming fresh tea leaves, and more particularly, to a tea leaf steaming method and apparatus capable of producing tea (sencha) having aroma and sweetness with kettle roasted green tea.
[0002]
[Prior art]
Green tea is processed through various processing steps such as a steaming process, a rough cooking process, a medium cooking process, and a finishing process. Among these, the steaming process introduces steam generated in the boiler into the rotary steamer, This is a process of obtaining appropriate steamed leaves necessary for the production of green tea by steaming fresh leaves with this steam. The steam used in this steaming process is introduced into the rotary steamer from the steam introducing cylinder in the steaming heat treatment apparatus, and steams the fresh tea leaves introduced from the fresh leaf inlet by steam latent heat.
[0003]
Through this steaming process, the activity of the oxidase in the fresh tea leaves is quickly lost, and the flavor unique to green tea is removed, excluding the green odor, and the tea leaves are softened so that the roughing process, which is the subsequent process, is smooth. It has a function to create a substrate that can be processed. Therefore, the quality of such steaming process greatly affects the quality of tea (especially sencha), and the suitability of steaming is an important process that affects the difficulty of the subsequent process.
[0004]
By the way, it is common to use 100 ° C. non-pressure saturated steam as steam introduced from the steam introduction cylinder into the rotary steam cylinder, and tea has been characterized by changing this steaming time. . That is, if steaming time is shortened, it becomes shallow steamed tea, and conversely, if steaming time is lengthened, it becomes deep steamed tea.
[0005]
However, since more consumers are demanding more characterized teas that are different from those characterized by changing the steaming time as described above, conventionally, instead of saturated steam, Thus, steaming fresh tea leaves with superheated steam at a temperature higher than 100 ° C. (about 120 to 400 ° C.) has been performed. By steaming fresh tea leaves with this superheated steam, tea (sencha) with a unique flavor like roasted tea can be obtained.
[0006]
[Problems to be solved by the invention]
However, in the conventional steaming method using superheated steam, a unique roasted tea is obtained, but the temperature of the steam is too high, and it is in contact with the tea leaves compared to when using no-pressure ordinary steam. When it does, there is a possibility that the way of heat transmission becomes worse, which may cause steaming and steaming. In other words, normal steam is steamed using the latent heat of steam 539.0 [cal / g · ° C.], whereas superheated steam (particularly at a temperature of 120 ° C. or higher) is about 0.49 [cal / g. Since only the amount of heat depending on the specific heat of [g · ° C.] can be used, the amount of heat becomes insufficient, and steaming is insufficient with only such superheated steam, causing problems for sencha.
[0007]
The present invention has been made in view of such circumstances, and it is possible to obtain a unique sencha that has sufficient aroma and sweetness in a kettle roasting style while sufficiently steaming to avoid young steaming and uneven steaming. An object is to provide a steaming heat treatment method and apparatus for tea leaves.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 is a steaming heat treatment method for tea leaves in which steam is applied to fresh tea leaves and a superheated steam process in which superheated steam at 120 to 400 ° C. is applied to tea leaves, and saturated steam at 100 ° C. is applied to tea leaves. It is characterized by including both a normal steam process.
[0009]
According to such a configuration, the raw tea leaves are given a flavor and sweetness in a kettle roasted style through the superheated steam process, and the heat treatment process is insufficient in the heated steam process by passing through the normal steam process. It shall be Note that either the superheated steam process or the normal steam process may be performed first. For example, the normal steam process may be performed after the superheated steam process, or the superheated steam process may be performed after the normal steam process. Also good.
[0010]
A second aspect of the present invention is a rotary steamer that is composed of a rotatable cylindrical member and that can accommodate tea leaves therein, and a raw leaf input for charging fresh tea leaves into the rotary steamer from one end side of the rotary steamer. Stirring the tea leaves accommodated in the mouth and the rotary steamer and transporting the tea leaves introduced from the fresh leaf inlet to the other end of the rotary steamer in cooperation with the rotation of the rotary steamer Means and a steam introduction cylinder for introducing steam into the rotary steam cylinder, wherein the steam introduction cylinder is overheated at 120 to 400 ° C. It is characterized by comprising a superheated steam introducing cylinder for introducing steam into the rotary steam cylinder and a normal steam introducing cylinder for introducing saturated steam at 100 ° C. into the rotating steam cylinder.
[0011]
According to such a configuration, the raw tea leaves are introduced into the rotary steamer from the raw leaf inlet, and the tea leaves are conveyed from one end side to the other end in cooperation with the rotary steamer while being stirred by the stirring means. During the conveyance, superheated steam and saturated steam are respectively introduced from the heated steam introducing cylinder and the ordinary steam introducing cylinder, and the raw tea leaves are heat-treated by the latent heat of evaporation.
[0012]
The invention according to claim 3 is characterized in that the superheated steam introducing cylinder and the ordinary steam introducing cylinder are respectively arranged in series with respect to the rotary steam cylinder.
[0013]
According to such a configuration, for the fresh tea leaves that are conveyed from one end side to the other end side while being stirred by the stirring means, heat treatment by superheated steam in the superheated steam introducing cylinder and in the normal steam introducing cylinder The heat treatment with saturated steam is performed in order (regardless of the order of processing).
[0014]
According to a fourth aspect of the present invention, the rotary furnace is composed of a first rotary furnace and a second rotary furnace arranged in series, and one ends of the first rotary furnace and the second rotary furnace. The superheated steam introducing cylinder and the normal steam introducing cylinder are respectively provided on the sides, and the stirring means is disposed through the first rotating cylinder and the second rotating cylinder.
[0015]
According to this configuration, the fresh tea leaves introduced from the fresh leaf inlet are heat-treated with saturated steam and saturated steam in the process of being transported through the first and second rotary steamers while being stirred by one stirring means. Will be performed in order (regardless of the order of processing).
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
The steam heat treatment apparatus according to the present embodiment heats the raw tea leaves with steam and performs heat treatment with latent heat of vaporization. As shown in FIG. 1, the first rotary steam cylinder 1, the second rotary steam cylinder 2, The raw leaf inlet 3, the stirring means 4, the superheated steam introducing cylinder 5, and the ordinary steam introducing cylinder 6 are mainly configured.
[0017]
The first rotary steamer 1 and the second rotary steamer 2 are placed on a movable machine frame 10 supported by a fixed machine frame 9 installed on the floor so as to be swingable via a horizontal shaft (not shown). As shown in FIG. 2, it is mainly composed of a cylindrical wire mesh cylinder 7 and a cylindrical tube body 8 that covers the outer peripheral surface of the wire mesh cylinder 7. In addition, although the cylinder 8 in the figure covers substantially the entire outer peripheral surface in the longitudinal direction of the metal mesh cylinder 7, instead of this, a part of the metal mesh cylinder 7 (for example, the outlet side portion) is not covered and exposed. You may use.
[0018]
The periphery of the first rotary cylinder 1 and the second rotary cylinder 2 is covered with the fixed cylinders 11 and 12, and is rotatable within the fixed cylinders 11 and 12 by the guide roller 24. The lower surfaces of the fixing cylinders 11 and 12 are open in the longitudinal direction, and a sink 13 that is inclined in the left direction in the figure is provided below the fixing cylinders 11 and 12. As a result, steamed leaves that have fallen from the lower surface opening can be received and collected, so that steamed leaves and the like are not scattered on the floor surface.
[0019]
Further, ring gears 14 and 15 are integrally fixed to one end (the left end in FIG. 1) of the first rotary steam cylinder 1 and the second rotary steam cylinder 2, and mesh with the ring gears 14 and 15, respectively. The drive gears 16 and 17 are pivotally supported on the movable machine frame 10. As a result, the drive gears 16 and 17 are respectively driven to rotate by a motor (not shown), whereby the ring gears 14 and 15 are rotated, and the first rotary cylinder 1 and the second rotary cylinder 2 can be rotated. Has been.
[0020]
The fresh leaf charging port 3 is composed of a hopper, and feeds fresh tea leaves into the first rotary steam cylinder 1 from one end (left end in FIG. 1) of the first rotary steam drum 1. The raw tea leaves introduced here are made into an appropriate amount by a leaf feeder disposed in the previous process of the steam heat treatment apparatus. Such a leaf feeder is a device for smoothing a raw leaf put into a bucket with a vibrating action of a side plate and a scraper and automatically feeding a constant amount to a steaming heat treatment apparatus.
[0021]
The stirring means 4 includes a stirring shaft 18 that extends slightly below the rotation center of the first rotary steam cylinder 1 and the second rotary steam cylinder 2, and a plurality of stirring hands that protrude substantially perpendicularly to the stirring shaft 18. 19. Then, when the stirring shaft 18 is rotated by driving a motor (not shown), the tea leaves accommodated in the first rotary steamer 1 and the second rotary steamer 2 are stirred by the stirrer 19 while the first rotary steamer 1 is stirred. In cooperation with the rotation of the barrel 1 and the second rotary steamer 2 (and in this embodiment, the inclination of these rotary steamers), the other end of the tea leaves introduced from the fresh leaf inlet 3 (the right end in FIG. 1). It is comprised so that it may convey.
[0022]
The superheated steam introduction cylinder 5 introduces superheated steam at 120 to 400 ° C. into the first rotary steam cylinder 1, and the other end of the pipe 20 connected at one end to a boiler (not shown) for generating superheated steam. A steam suction port 5a that can be connected to each other is formed, and a steam chamber 22 that can be filled with steam is formed inside. Thereby, the superheated steam generated in the boiler reaches the steam chamber 22 and heat-treats the fresh tea leaves (superheated steam process).
[0023]
The normal steam introduction cylinder 6 introduces saturated steam at 100 ° C. into the second rotary steam cylinder 2, and one end thereof is a boiler for generating saturated steam (separately provided from the boiler for generating superheated steam). A steam suction port 6 a that can connect the other end of the connected pipe 21 is formed, and a steam chamber 23 that can be filled with steam is formed inside, as in the superheated steam introduction cylinder 5. As a result, the saturated steam generated in the boiler reaches the steam chamber 23 and heat-treats (normal steam process) the tea leaves that have been heat-treated in the superheated steam introduction cylinder 5.
[0024]
That is, the superheated steam introducing cylinder 5 and the ordinary steam introducing cylinder 6 are respectively arranged in series with respect to the rotating steam cylinders (the first rotating steam cylinder 1 and the second rotating steam cylinder 2). 1, the tea leaves that have been subjected to the superheated steam process can be directly conveyed to the second rotary steamer 2. Further, since the stirring shaft 18 of the stirring means 4 is disposed through the first rotary steam cylinder 1 and the second rotary steam cylinder 2, the stirring means to be provided in each steam cylinder can be shared, The apparatus can be simplified as compared with the case where each has a stirring shaft.
[0025]
Next, the operation of the steam heat treatment apparatus having the above configuration will be described.
First, the movable machine frame 10 is adjusted to swing with respect to the fixed machine frame 9 so that the right end sides of the first rotary cylinder 1 and the second rotary cylinder 2 are inclined downward, and a motor (not shown) is turned on after the adjustment. Then, the drive gears 16 and 17 are driven to rotate. With this rotational drive, rotational force is transmitted to each of the ring gears 14 and 15, and the first rotary cylinder 1 and the second rotary cylinder 2 rotate on the guide roller 24.
[0026]
Further, by turning on a separate motor (not shown), the stirring shaft 18 is rotated in the same direction as the first rotary cylinder 1 and the second rotary cylinder 2. The rotation of the stirring shaft 18 is rotationally driven at a slightly higher rotational speed than that of the first rotating steam cylinder 1 and the second rotating steam cylinder 2, and the stirring hand 19 fixed thereto is also rotated in conjunction with it. In addition, the structure which the 1st rotation steam cylinder 1 and the 2nd rotation steam cylinder 2, and the stirring shaft 18 begin to rotate simultaneously by one switch may be sufficient.
[0027]
Thereafter, when a fresh tea leaf is introduced from the fresh leaf inlet 3, the raw tea leaf moves from the left end side to the right end side in FIGS. 1 and 3 while being heat-treated. This movement is due to the first rotating steam cylinder 1 and the second rotating steam cylinder 2 rotating while slightly tilting to the right, but the stirring action by the stirrer 19 and the first rotating steam cylinder 1 and the second rotating steam cylinder 2. The transporting action is imparted to the tea leaves also in cooperation with.
[0028]
Further, a stirring hand 19 having a slightly higher rotational speed than the first rotary steamer 1 and the second rotary steamer 2 is stirring the tea leaves accumulated at the bottoms of the rotary steamers 1 and 2 upward. In the first rotary steam cylinder 1, heat treatment is performed by receiving the latent heat of steam while touching the superheated steam introduced from the superheated steam introduction cylinder 5 by the stirring action of the stirrer 19 and the rotating action of the first rotary steam cylinder 1. On the other hand, in the second rotary steam cylinder 2, heat treatment is performed by receiving the latent heat of steam while touching the saturated steam introduced from the normal steam introducing cylinder 6 by the stirring action of the stirrer 19 and the rotating action of the second rotary steam cylinder 2. Is done.
[0029]
That is, the fresh tea leaves introduced from the fresh leaf inlet 3 are subjected to superheated steam in the first rotary steam cylinder 1 and subjected to the superheated steam process, and then reach the second rotary steam cylinder 2 where saturated steam (nothing The normal steam process is performed by applying normal pressure), so that a series of continuous heat treatments can be performed without an operator.
[0030]
According to the superheated steam process, 120-400 ° C superheated steam is applied to the tea leaves and heat-treated, so it is possible to obtain a unique tea with a kettle roast, but since such superheated steam has a low specific heat, Sufficient steaming is not performed, and there is a possibility that the oxidase cannot be sufficiently killed. In this embodiment, since a normal steam process is performed in which saturated steam at 100 ° C. with high specific heat is applied to the tea leaves, it has a flavor and sweetness that is unique in the roasting style and suppresses the activity of oxidase. You can get tasencha.
[0031]
Although the present embodiment has been described above, the present invention is not limited to this. For example, the arrangement positions of the superheated steam introducing cylinder and the normal steam introducing cylinder are switched, and the first rotating steam cylinder 1 is provided with 100. A saturated steam at 0 ° C. may be introduced, and superheated steam at 120 to 400 ° C. may be introduced into the second rotary steam cylinder 2. That is, even if the superheated steam process using the superheated steam is performed after the normal steam process using the saturated steam, the same effect as the above embodiment can be obtained.
[0032]
Further, in the present embodiment, the first rotary steam cylinder 1 and the second rotary steam cylinder 2 are rotationally driven by separate drive sources, but the ring gear is formed only at the left end of the first rotary steam cylinder 1. In addition, the second rotary steam cylinder 2 may be connected so as to be integrated with this. According to this, only one drive system for rotating the steam cylinder is required, and the apparatus configuration can be simplified.
[0033]
Further, since the boilers connected to the superheated steam introduction cylinder 5 and the normal steam introduction cylinder 6 have different pressures of the generated steam, it is necessary to use separate ones. However, one boiler generates saturated steam. Further, the heating steam may be further heated to the superheated steam introduction cylinder 5 side, and the saturated steam may be sent to the normal steam introduction cylinder 6 side as it is.
[0034]
【The invention's effect】
According to the first and second aspects of the invention, both the heat treatment with superheated steam and the heat treatment with saturated steam are performed, so that the heat treatment is sufficiently performed to avoid the steaming and uneven steaming. You can get a unique sencha with fragrance and sweetness.
[0035]
According to the invention of claim 3, since the superheated steam introducing cylinder and the ordinary steam introducing cylinder are respectively arranged in series with the rotary steam cylinder, the fresh tea leaves introduced from the fresh leaf inlet are carried out of the rotary steam cylinder. In this process, heat treatment with superheated steam and heat treatment with ordinary steam can be performed in order, and it is not necessary to intervene workers in these heat treatments.
[0036]
According to invention of Claim 4, since the stirring means is arrange | positioned through the 1st rotary steam cylinder and the 2nd rotary steam cylinder, the stirring means can be made common and the apparatus can be simplified. Can do.
[Brief description of the drawings]
FIG. 1 is a front view showing a steaming heat treatment apparatus for tea leaves according to an embodiment of the present invention. FIG. 2 is a front view showing a rotary steam cylinder in the steaming heat treatment apparatus for tea leaves according to an embodiment of the present invention. Sectional view showing a tea leaf steaming heat treatment apparatus according to an embodiment of the present invention
DESCRIPTION OF SYMBOLS 1 ... 1st rotation steam cylinder 2 ... 2nd rotation steam cylinder 3 ... Fresh-leaf injection port 4 ... Stirring means 5 ... Superheated steam introduction cylinder 6 ... Normal steam introduction cylinder 7 ... Wire mesh cylinder 8 ... Cylindrical body 9 ... Fixed machine frame 10 ... Movable machine frames 11, 12 ... fixed barrel 13 ... sinks 14, 15 ... ring gears 16, 17 ... drive gear 18 ... stirring shaft 19 ... stirring hands 20, 21 ... piping 22, 23 ... steam chamber 24 ... guide roller

Claims (4)

In the steaming heat treatment method for tea leaves, where steam is applied to the raw tea leaves for heat treatment,
A superheated steam process of applying 120 to 400 ° C superheated steam to the tea leaves;
A normal steam process in which saturated steam of 100 ° C is applied to tea leaves;
A steam-heat treatment method for tea leaves characterized by comprising both of the above. A rotating steam cylinder that is made of a rotatable cylindrical member and can accommodate tea leaves inside,
A fresh leaf inlet for feeding fresh tea leaves into the rotary steamer from one end side of the rotary steamer,
Agitating means for agitating the tea leaves accommodated in the rotary steamer, and conveying tea leaves introduced from the raw leaf inlet to the other end side of the rotary steamer in cooperation with the rotation of the rotary steamer,
A steam introduction cylinder for introducing steam into the rotary steam cylinder;
In a steaming heat treatment apparatus for tea leaves that performs heat treatment by applying steam to fresh tea leaves,
The steam introducing cylinder is
A superheated steam introduction cylinder for introducing superheated steam at 120 to 400 ° C. into the rotary steam cylinder;
A normal steam introduction cylinder for introducing saturated steam at 100 ° C. into the rotary steam cylinder;
An apparatus for steaming heat treatment of tea leaves, comprising: 3. The tea leaf steaming heat treatment apparatus according to claim 2, wherein the superheated steam introducing cylinder and the ordinary steam introducing cylinder are arranged in series with respect to the rotary steam cylinder. The rotary steam cylinder is composed of a first rotary steam cylinder and a second rotary steam cylinder arranged in series, and the superheated steam introduction cylinder is respectively provided at one end side of the first rotary steam cylinder and the second rotary steam cylinder. 4. The apparatus according to claim 2, wherein a normal steam introducing cylinder is provided, and the stirring means is disposed through the first rotating cylinder and the second rotating cylinder. 5. Steaming heat treatment equipment for tea leaves.

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