Tea leaf fermentation device

Abstract

The present application relates to black tea fermentation technical field, especially to a kind of tea fermentation device, including the box of being isolated two regions, further include: air blowing system, for providing airflow flow power for tea fermentation;Humidity supply device, the humidity supply device includes water storage tank, flow regulating water pump, conveying pipe and atomizing nozzle, the flow regulating water pump is used to introduce the water in water storage tank to atomizing nozzle place.Processing the data of humidity and temperature detection of each position in fermentation tank by PLC control device in control device when each point data is not in the ideal condition of fermentation, PLC control device can control air blower and flow regulating water pump to carry out real-time compensation in fermentation tank, so as to achieve the purpose of dynamically adjusting the humidity and temperature inside fermentation tank, the device has low cost, easy to maintain, and dynamically adjust the internal environment, tea fermentation tastes better, and there is no need for artificial experience judgment in fermentation process.

Description

Technical Field

[0001] This invention relates to the field of black tea fermentation technology, and in particular to a tea fermentation apparatus. Background Technology

[0002] In the process of making black tea, fermentation is a key step that determines the final flavor. Common fermentation methods include box fermentation and room fermentation, in which the tea leaves are spread flat on the sieve of a rack and then fermented by steam input.

[0003] The above-mentioned fermentation method is a common fermentation process. Due to the layered and flattened fermentation method, it is difficult to ensure that the tea leaves at different heights are in the optimal fermentation temperature and humidity environment. The humidity and temperature of the tea leaves in each layer are different. As a result, the tea leaves fermented in the same batch are not uniform in the degree of enzymatic reaction during the fermentation process, which makes it difficult to meet the process requirements of high-quality black tea. Moreover, relying on manual experience is inefficient. Summary of the Invention

[0004] The purpose of this invention is to provide a tea fermentation device that can dynamically adjust humidity and temperature according to the real-time environment inside the fermentation chamber. This device is low in cost, suitable for widespread application, and has the advantages of high efficiency and better taste in the later stages of production.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a tea fermentation device, comprising a box separated into two areas, and further comprising: The blower system is used to provide airflow power for tea fermentation; A humidity supply device, comprising a water tank, a flow regulating water pump, a delivery pipe, and an atomizing nozzle, wherein the flow regulating water pump is used to introduce water from the water tank to the atomizing nozzle, and the atomizing nozzle is disposed in the airflow channel of the blower system. A steam generator is provided at the tail end of the airflow channel of the blower system. The steam generator includes a ceramic heating core and an outer heat insulation sleeve, and an annular space is provided between the ceramic heating core and the outer heat insulation sleeve. The control device includes a PLC control unit, a frequency modulator, a power control switch, and a data collection and feedback device. The PLC control unit is electrically connected to the blower, the flow regulating water pump, the ceramic heating core, the frequency modulator, the power control switch, and the data collection and feedback device.

[0006] Furthermore, the atomizing nozzle includes multiple annular atomizing sections spaced apart from the outside to the inside, with flared gaps and converging gaps spaced apart between the multiple annular atomizing sections.

[0007] Furthermore, the flaring gap includes a first arc-shaped flaring opening disposed at the windward opening, an arc-shaped tightening opening connected to the first arc-shaped flaring opening, and a dispersing opening connected to the arc-shaped tightening opening.

[0008] Furthermore, the converging opening gap includes a second arc-shaped flare disposed at the windward opening, and a converging opening connected to the second arc-shaped flare and used to increase the airflow velocity.

[0009] Furthermore, the ceramic heating core is also provided with multiple regulating air channels, and the two sides of the outer heat insulation sleeve are fixed to the tail end of the airflow channel of the blower system through connecting flanges.

[0010] Furthermore, it also includes an adjustable airway, which consists of a tubular airway and an airway with a spindle-shaped cross-section.

[0011] Furthermore, it also includes an adjustment core, which is located in the middle of the inner cavity of the adjustment airway. The adjustment core includes a large elliptic part, a frustum part, and a conical end part.

[0012] Furthermore, the windward side of the adjusting core is provided with a movable opening, and one end of the elastic rod is fixedly inserted into the movable opening.

[0013] Furthermore, the system is equipped with a drying room for concentrating the airflow introduced by the tea fermentation device, wherein a rack is placed inside the drying room and an external exhaust duct is provided on the top of the drying room; It also includes a communication line, and a temperature detection device and a humidity detection device are installed on the communication line and at the position of the tray on the placement rack. The placement racks are arranged neatly side by side; The drying chamber is equipped with a valve that connects to the outlet of the steam generator.

[0014] A method for controlling tea fermentation, applied in a tea fermentation device, involves introducing airflow into the fermentation chamber and dynamically adjusting the internal temperature and humidity. The method comprises the following steps: S1: Initially set the fermentation temperature and humidity, and input them into the PLC control device; S2: The PLC control device controls the power of the blower and the flow regulating water pump through the power control switch and frequency converter, and at the same time starts the ceramic heating core, so that the temperature inside the ceramic heating core rises; the airflow guides the water vapor generated by the annular atomization part into the ceramic heating core, and after being heated by the ceramic heating core, the high-temperature steam is dispersed into the drying room; S3: The PLC control device collects data from multiple temperature and humidity sensors in the drying oven through a data collection and feedback device. When the average humidity reaches 90% and the average temperature stabilizes within the range of 27-33 degrees Celsius, the PLC control device stops the blower, flow regulating water pump, and ceramic heating element. When the average humidity does not reach 90% and the average temperature is not within the range of 27-33 degrees Celsius, the PLC control device continues to operate the blower, flow regulating water pump, and ceramic heating element.

[0015] The technical effects and advantages of this invention are as follows: 1. The present invention uses a PLC control device to process the humidity and temperature data detected at various locations in the fermentation chamber. When the data at each location is not under ideal fermentation conditions, the PLC control device can control the blower and flow regulating water pump to compensate in real time, thereby achieving the purpose of dynamically adjusting the humidity and temperature inside the fermentation chamber.

[0016] 2. This invention places the atomizing nozzle within the airflow channel, allowing it to enter the steam generator via atomization. Steam is formed at the front end of the fermentation chamber, and this atomized water vapor is rapidly heated and evaporated into high-temperature steam with high purity. This not only makes the steam entering the fermentation chamber lighter but also increases the steam entry speed through convergence, thereby increasing the head distance. Furthermore, it generates turbulence and disturbance within the fermentation chamber, resulting in more uniform steam dispersion. This ensures that tea leaves at different heights are more evenly distributed under suitable temperature and humidity conditions, and also reduces condensation.

[0017] 3. This device is low in cost, easy to maintain, and dynamically adjusts the internal environment, resulting in better taste from fermented tea. No manual judgment is required during the fermentation process, leading to higher fermentation efficiency. Attached Figure Description

[0018] Figure 1 This is a front view of the present invention; Figure 2 This is a cross-sectional view of the perspective of the present invention; Figure 3 This is a schematic diagram of the housing of the present invention; Figure 4 This is a cross-sectional view of the housing and steam generator of the present invention; Figure 5 This is a rear view of the housing of the present invention; Figure 6 This is a schematic diagram of the atomizing nozzle of the present invention; Figure 7 This is a front sectional view of the atomizing nozzle of the present invention; Figure 8 This is a cross-sectional view of the steam generator of the present invention; Figure 9 This is a schematic diagram of another embodiment of the steam generator of the present invention; Figure 10 This is a schematic diagram illustrating the principle of the control method during the fermentation process of this invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Reference Figures 1 to 10 The tea fermentation device shown includes a box 3 with two isolated areas. The front area is used to install a blower system 6, a humidity supply device 5, and a steam generator 7. The rear area is used to install a frequency modulator 10, a power control switch 9, and a data collection and feedback device 11. The control part and the hardware part are separated by a vertical plate set in the middle to avoid mutual interference and make maintenance more convenient. The blower system 6, the humidity supply device 5, and the steam generator 7 are open-type designs, while the frequency modulator 10, the power control switch 9, and the data collection and feedback device 11 are isolated from the outside by a transparent door.

[0021] like Figure 3 and Figure 4 The blower system 6 shown is used to provide airflow power for tea fermentation. The blower 61 drives the fan blades 62 inside the pump casing to rotate. The generated airflow enters the steam generator 7 through the airflow pipe 63. The blower 61 is a frequency converter. The speed of the blower 61 is controlled by the frequency converter 10, which can adjust the airflow speed and flow rate. Specifically, a 4-72 type centrifugal fan is used. It is a small model with an air volume of 300-600 m³ / h and adjustable air pressure. like Figure 3 and Figure 4 The humidity supply device 5 shown includes a water tank 4, a flow regulating water pump 51, a delivery pipe 52, and an atomizing nozzle. The flow regulating water pump 51 is used to introduce water from the water tank 4 to the atomizing nozzle, and the atomizing nozzle is located in the airflow channel of the blower system 6. It should be noted that the flow regulating water pump 51 also adopts a frequency conversion design. By controlling the flow regulating water pump 51, the amount of steam entering the chamber can be controlled. It can also quickly replenish humidity when a large humidity difference is detected inside, resulting in higher efficiency.

[0022] like Figure 6As shown, it should be further explained that the atomizing nozzle includes multiple annular atomizing portions 53 spaced apart from the outside to the inside, and the multiple annular atomizing portions 53 are spaced apart with flaring gaps 54 and converging gaps 55.

[0023] Because existing steam generators use water heat exchange to produce steam, the steam purity is not high, it contains a lot of water molecules, and there will be heat loss during the flow into the fermentation tank, which will cause the following problems. Problem 1: This leads to increased moisture in the channels, resulting in excessive water accumulation at the steam vent of the fermentation chamber. Problem 2: Water vapor condenses quickly inside the fermentation chamber, increasing its mass and shortening the head distance. It tends to accumulate at the front of the fermentation chamber, resulting in poor fermentation. Question 3: Increased water consumption.

[0024] This solution places the atomizing nozzle within the airflow channel, allowing the steam to enter the steam generator 7 via atomization. Steam is formed at the front end of the fermentation chamber, and this atomized water vapor is quickly heated and evaporated into high-temperature steam with high purity. This not only makes the steam entering the fermentation chamber lighter but also increases the steam entry speed through convergence, thereby increasing the head distance. Furthermore, the turbulence generated inside the fermentation chamber ensures more even steam distribution, resulting in more uniform tea leaves at different heights under suitable temperature and humidity conditions, and reducing condensation.

[0025] The following explanations are also needed regarding the flaring gap 54 and the converging gap 55: The flared gap 54 disperses the airflow, meaning the airflow range is wider. The airflow is dispersed from the annular flared gap 54 to the axis of the atomizing nozzle and its periphery. This allows the water mist generated by the atomizing nozzle to form a more dispersed atmosphere. Furthermore, the annular flared gap between the atomizing nozzle and the connecting flange 72 also allows for dispersed airflow. This further enhances the atomization effect entering the steam generator 7. Combined with the strong airflow generated by the converging gap 55, the flow velocity of the water mist is increased, ensuring that the water mist enters the multiple regulating air passages 74 evenly. This guarantees higher purity and more thorough heating of the steam generated in each regulating air passage 74.

[0026] In the above embodiments, the specific method of forming dispersed water mist at the axis of the atomizing nozzle and at the periphery of the atomizing nozzle is described in reference [reference needed]. Figure 7 The flared gap 54 shown includes a first arc-shaped flared opening 541 provided at the windward opening, an arc-shaped tightening opening 542 connected to the first arc-shaped flared opening 541, and a dispersing opening 543 connected to the arc-shaped tightening opening 542.

[0027] When the airflow generated by the blower 61 passes through the flared connecting flange 72, because the atomizing nozzle is located in the center, part of the airflow is gathered by the arc-shaped constricting port 542 after passing through the first arc-shaped flare port 541. At this time, the airflow velocity increases, and after passing through the dispersion port 543, it flows along the outer and inner walls of the dispersion port 543, thus improving the atomization range.

[0028] In the above embodiment, the converging gap 55 includes a second arc-shaped flare 551 disposed at the windward opening, and a converging opening 552 connected to the second arc-shaped flare 551 and used to increase the airflow velocity.

[0029] The converging gap 55 is located at the center of the flaring gap 54. The converging gap 55 generates an accelerated airflow to ensure that the atomized water vapor is evenly dispersed between the atomizing nozzle and the ceramic heating core 73. This ensures that the water mist entering the multiple regulating air channels 74 is more uniform, so that the steam generated after the water vapor is heated is purer, reducing the water vapor content in the steam and ensuring that the humidity and temperature entering the fermentation chamber rise evenly.

[0030] like Figure 8 The steam generator 7 shown is located at the tail end of the airflow channel of the blower system 6. The steam generator 7 includes a ceramic heating core 73 and an outer heat insulation sleeve 71. An annular space A is provided between the ceramic heating core 73 and the outer heat insulation sleeve 71. The annular space A isolates heat loss and serves as insulation. Current is used to heat ceramic materials, such as PTC ceramics, utilizing their rapid thermal conductivity and high-temperature stability to heat the liquid to its vaporization point, thereby generating steam. The uniform heating characteristics of ceramics contribute to efficient energy conversion.

[0031] The ceramic heating core 73 is used to heat the airflow passing through the airflow duct 63, and the atomizing nozzle indirectly compensates for the humidity in the airflow.

[0032] In one embodiment, the ceramic heating core 73 is also provided with multiple regulating air passages 74, and the outer heat insulation sleeve 71 is fixed to the end of the airflow passage of the blower system 6 on both sides by connecting flanges 72.

[0033] In the implementation of the above embodiments, an adjusting airway 74 is also included, which consists of a tubular airway 741 and a shuttle-shaped airway 742. Figure 9 The cross-section of the airway 742 is shuttle-shaped and is adapted to the shape of the regulating core 76. The regulating core 76 is located in the middle of the inner cavity of the regulating airway 74. The regulating core 76 includes a large elliptical part 761, a frustum part 762 and a conical end part 763.

[0034] Considering the preheating stage of the fermentation chamber, or in cases of low local temperature and humidity, especially after tea leaves are layered, there are differences in humidity and temperature distribution in tea leaves at different heights. In addition to increasing the speed of the blower 61 and the amount of steam, it is necessary to increase the gas flow time to achieve the target temperature. By improving the shape of the original regulating air passage 74, the elliptical surface of the large elliptical part 761 can be increased to accommodate the increase in airflow velocity. This causes the entire regulating core 76 to move to one side of the shuttle-shaped air passage 742, and then the large elliptical part 761 moves to the original position of the frustum part 762. Since the shuttle-shaped air passage 742 is adapted to the shape of the regulating core 76, the gap reserved for airflow is reduced, the pressure at the front end is increased, and the airflow velocity at the rear end of the regulating core 76 is faster. The advantage of this setting is that: By controlling the airflow at the front end, the water mist carried by the accelerated airflow is fully heated at the position of the tubular air passage 741, thereby improving the full evaporation of water vapor. Adjusting the speed at the rear end of the regulating core 76 allows the airflow at the rear end of the regulating core 76 to enter the fermentation chamber at a faster speed, resulting in a faster airflow speed inside the fermentation chamber and more uniform internal heat distribution.

[0035] To ensure that the regulating core 76 can move axially, the windward side of the regulating core 76 is provided with a movable opening, and one end of the elastic rod 75 is fixedly inserted into the movable opening. When the airflow is large, it means that the internal heat and steam need to be replenished. In this way, by changing the airflow velocity, the regulating core 76 can respond synchronously, thereby ensuring that the airflow velocity entering the fermentation chamber is faster.

[0036] It is important to note that the airflow velocity entering the fermentation chamber should not exceed 3 meters per second.

[0037] The control unit includes a PLC control unit 8, a frequency modulator 10, a power control switch 9, and a data collection and feedback device 11. The PLC control unit 8 is electrically connected to the blower 61, the flow regulating water pump 51, the ceramic heating core 73, the frequency modulator 10, the power control switch 9, and the data collection and feedback device 11. The power control switch 9 is a TS series SCR power regulator. The PLC control unit 8 includes an input module, a central processing unit, and an output module. The input module receives signals from sensors, switches, and other input devices. The central processing unit processes these signals and executes corresponding operations. It can also be programmed using various programming languages ​​and has advantages such as strong programmability, fast response speed, high reliability, easy maintenance and debugging, and easy expansion and configuration.

[0038] A fermentation room is provided, which is equipped with a function to gather the airflow introduced by the tea fermentation device. It includes a drying room 1, in which a rack 1-1 is placed, and the rack 1-1 has eight trays. An external exhaust duct 2 is provided on the top of the drying room 1. The dimensions of the drying room 1 are: length 4 meters, width 3 meters, and height 2 meters.

[0039] It also includes a communication line 12, and a temperature detection device 13 and a humidity detection device 14 are installed on the communication line 12 and on the pallet located on the placement rack 1-1. The number of temperature detection devices 13 and humidity detection devices 14 is 1 to 96, which are distributed at the pallet climbing position of the placement rack 1-1 to measure the temperature and humidity at the pallet.

[0040] Among them, the temperature detection device 13 is an FG6020 model temperature sensor with a measurement range of -40℃ to 120℃; the humidity detection device 14 is an FG6020 model humidity sensor with a measurement range of 0 to 99.9%RH.

[0041] The placement racks 1-1 are arranged neatly side by side. The existing structure of the placement racks 1-1 is optimized so that the outer edge of the tray is flush with the outer side of the placement racks 1-1, so that the trays on the placement racks 1-1 are gathered and close together. This can divide the drying room 1 into flow fields of different heights, which is conducive to maintaining the temperature and humidity in each flow field under standard fermentation conditions.

[0042] The drying chamber 1 is equipped with an air inlet connected to the outlet of the steam generator 7, with an air inlet area of ​​3.14 × 400 mm. 2 The area of ​​the external exhaust duct 2 is 3.14 × 1400 mm. 2 ; like Figure 10 The method for controlling tea fermentation, as shown, is applied to a tea fermentation device by introducing airflow into the fermentation chamber and dynamically adjusting the internal temperature and humidity. The method includes the following steps: S1: Initially set the fermentation temperature and humidity, and input them into the PLC control device 8; S2: The PLC control device 8 controls the power of the blower 61 and the flow regulating water pump 51 through the power control switch 9 and the frequency modulator 10, and at the same time starts the ceramic heating core 73, so that the temperature inside the ceramic heating core 73 rises; the airflow guides the water vapor generated by the annular atomizing part 53 into the ceramic heating core 73, and after being heated by the ceramic heating core 73, the high-temperature steam is dispersed into the drying room 1; S3: The PLC control device 8 collects data from multiple temperature detection devices 13 and humidity detection devices 14 in the drying room 1 through the data collection and feedback device 11. When the average humidity reaches 90%, the average temperature stabilizes in the range of 27-33 degrees Celsius. The PLC control device 8 controls the blower 61, the flow regulating water pump 51, and the ceramic heating core 73 to stop. When the average humidity does not reach 90%, and the average temperature is not in the range of 27-33 degrees Celsius, the blower 61, the flow regulating water pump 51, and the ceramic heating core 73 are controlled to continue working.

[0043] The data collection and feedback device 11 collects temperature data from the temperature detection device 13 (96 points) and humidity data from the humidity detection device 14 (96 points). The collected data is transmitted to the PLC via a communication interface. After receiving the data, the PLC control device 8 performs data parsing and processing, including calculating the temperature and humidity at each location, as well as the average temperature and humidity at the 96 points. Data filtering and average value calculation are implemented in the PLC. Weighted average or median filtering algorithms can also be introduced to improve the stability and accuracy of the data.

[0044] This application takes black tea fermentation as an example. When using this fermentation device to ferment black tea, you only need to input the temperature and humidity during fermentation into the PLC control device 8, and the temperature inside the fermentation chamber can be dynamically adjusted in real time.

[0045] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tea fermentation apparatus, comprising a box (3) separated into two areas, characterized in that, Also includes: The blower system (6) is used to provide airflow power for tea fermentation; Humidity supply device (5), the humidity supply device (5) includes a water tank (4), a flow regulating water pump (51), a delivery pipe (52) and an atomizing nozzle. The flow regulating water pump (51) is used to introduce water in the water tank (4) to the atomizing nozzle, and the atomizing nozzle is set in the airflow channel of the blower system (6). A steam generator (7) is provided at the tail end of the airflow channel of the blower system (6). The steam generator (7) includes a ceramic heating core (73) and an outer heat insulation sleeve (71). An annular space (A) is provided between the ceramic heating core (73) and the outer heat insulation sleeve (71). The control device includes a PLC control device (8), a frequency modulator (10), a power control switch (9), and a data collection and feedback device (11). The PLC control device (8) is electrically connected to a blower (61), a flow regulating water pump (51), a ceramic heating core (73), a frequency modulator (10), a power control switch (9), and a data collection and feedback device (11).

2. The tea fermentation apparatus according to claim 1, characterized in that, The atomizing nozzle includes multiple annular atomizing sections (53) spaced apart from the outside to the inside, with annular atomizing sections (53) having spaced flaring gaps (54) and converging gaps (55) between them.

3. The tea fermentation apparatus according to claim 2, characterized in that, The flaring gap (54) includes a first arc-shaped flaring (541) provided at the windward opening, an arc-shaped tightening opening (542) connected to the first arc-shaped flaring (541), and a dispersing opening (543) connected to the arc-shaped tightening opening (542).

4. The tea fermentation apparatus according to claim 2, characterized in that, The converging opening gap (55) includes a second arc-shaped flare (551) provided at the windward opening, and a converging opening (552) connected to the second arc-shaped flare (551) and used to increase the airflow velocity.

5. The tea fermentation apparatus according to claim 1, characterized in that, The ceramic heating core (73) is also provided with multiple regulating air channels (74), and the outer heat insulation sleeve (71) is fixed on both sides to the end of the airflow channel of the blower system (6) by connecting flanges (72).

6. A tea fermentation apparatus according to claim 5, characterized in that, It also includes an regulating airway (74), which consists of a tubular airway (741) and a shuttle-shaped airway (742).

7. A tea fermentation apparatus according to claim 6, characterized in that, It also includes an adjustment core (76), which is located in the middle of the inner cavity of the adjustment airway (74). The adjustment core (76) includes a large elliptic part (761), a frustum part (762), and a conical end part (763).

8. A tea fermentation apparatus according to claim 7, characterized in that, The windward side of the adjusting core (76) is provided with a movable opening, and one end of the elastic rod (75) is fixedly inserted into the movable opening.

9. A tea fermentation apparatus according to claim 8, characterized in that, It also includes a drying room (1), in which a rack (1-1) is placed, and an external exhaust duct (2) is provided on the top of the drying room (1); It also includes a communication line (12), and a temperature detection device (13) and a humidity detection device (14) are provided on the communication line (12) and on the tray located on the placement rack (1-1). The placement racks (1-1) are arranged neatly side by side; The drying room (1) is equipped with an outlet that communicates with the steam generator (7).

10. A method for controlling tea fermentation, applied to a tea fermentation apparatus as described in claims 1-9, wherein after airflow is introduced into the fermentation chamber by the tea fermentation apparatus, the internal temperature and humidity are dynamically adjusted, characterized in that... Includes the following steps: S1: Initially set the fermentation temperature and humidity, and input them into the PLC control device (8); S2: The PLC control device (8) controls the power of the blower (61) and the flow regulating water pump (51) through the power control switch (9) and the frequency modulator (10), and at the same time starts the ceramic heating core (73), so that the temperature inside the ceramic heating core (73) rises; the airflow guides the water vapor generated by the annular atomizing part (53) to the ceramic heating core (73), and after being heated by the ceramic heating core (73), the high-temperature steam is dispersed into the drying room (1); S3: The PLC control device (8) collects data from multiple temperature detection devices (13) and humidity detection devices (14) in the drying room (1) through the data collection feedback device (11). When the average humidity reaches 90%, the average temperature stabilizes in the range of 27-33 degrees Celsius. The PLC control device (8) controls the blower (61), the flow regulating water pump (51), and the ceramic heating core (73) to stop. When the average humidity does not reach 90%, the average temperature is not in the range of 27-33 degrees Celsius. The blower (61), the flow regulating water pump (51), and the ceramic heating core (73) are controlled to continue working.

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