Heating box and tea dryer with same

Abstract

The heating box comprises a box body and a plurality of electric heating pipes arranged in the box body, an air inlet and an air outlet are formed in the two sides of the box body respectively, each electric heating pipe is sleeved with a metal pipe, and a temperature control space is formed between each metal pipe and the corresponding electric heating pipe. According to the heating box, air enters from the ventilation opening in the fixing plate and the air inlet of the box body, air exits from the ventilation hole in the metal pipe and the air outlet of the box body, after the electric heating pipe is electrified and preheated, the temperature of the temperature control space rises, the metal pipe conducts heat, the temperature in the heating box rises fast, and the electrifying time can be properly shortened; when the electric heating pipes are powered off at intervals, cold air is blown to the surfaces of the metal pipes and does not directly exchange heat with the temperature control space in the metal pipes, so that cooling in the temperature control space is slow, hot air flows out of the ventilation holes of the metal pipes, the cooling speed of the heating box is relatively slow, the power-off time of the electric heating pipes can be prolonged, the total power-on time is shortened, and the service life of the heating box is prolonged. The energy consumption is further reduced.

Description

Technical Field

[0001] The utility model relates to the field of tea processing equipment, in particular to a heating box and a tea drying machine provided with the heating box. Background Art

[0002] In the tea processing process, drying is one of the key links in determining the quality of tea. When using a dryer for baking, the baking temperature needs to be controlled within an appropriate range. Traditional tea dryers will have an electric heating tube installed at the air outlet of the fan to heat and provide hot air for drying. However, the electric heating tube will continue to heat up when powered on. In order to avoid the high temperature from the electric heating tube to the tea leaves affecting the processing quality, a cooling fan will be installed to blow cold air into the drying box to cool it down. In this type of dryer, both the cooling fan and the electric heating tube need to be powered on continuously, which consumes a lot of energy.

[0003] In view of the above defects, the existing improved method is to intermittently energize the electric heating tube in the dryer, that is, when the temperature of the heating box exceeds the required range, the electric heating tube is powered off, and the continuously working fan cools the heating box. When it drops to a suitable temperature, the electric heating tube is powered on, and the cycle continues. Intermittent heating shortens the overall power-on time, reduces energy loss to a certain extent, and is beneficial to energy conservation and environmental protection. However, the fan continues to supply air when the electric heating tube is powered off, causing the electric heating tube to cool down quickly. Therefore, the interval power-off time is short, and there is still a large energy loss. Utility Model Content

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A heating box comprises a box body and a plurality of electric heating tubes arranged in the box body, air inlets and air outlets are arranged on both sides of the box body, each electric heating tube is sheathed with a metal tube, and a temperature control space is formed between the metal tube and the electric heating tube.

[0006] Furthermore, the box body is composed of two front and rear U-shaped plates and two upper and lower side plates. The left and right ends of the box body form the air outlet and the air inlet. The opening directions of the two U-shaped plates are arranged in back to back directions. Fixed plates for fixing the electric heating tubes are respectively provided in the openings of the U-shaped plates. A reverse air plate for guiding hot air is provided on one side of the air outlet of the box body.

[0007] Furthermore, the two ends of the electric heating tube pass through two C-shaped plates respectively and are fixedly connected to the fixing plate; the two ends of the metal tube pass through two C-shaped plates respectively and are fixedly connected to the C-shaped plates.

[0008] Furthermore, at least one of the two fixing plates is provided with a plurality of ventilation openings.

[0009] Furthermore, the metal tube is provided with a plurality of ventilation holes facing the air outlet.

[0010] Furthermore, the electric heating tubes are arranged in a matrix in a plurality of rows in the box, each row is composed of a plurality of electric heating tubes arranged at intervals, and two adjacent rows of electric heating tubes are arranged in a staggered manner.

[0011] Furthermore, the electric heating tube is a fin-type heating tube.

[0012] Furthermore, the metal tube is made of stainless steel.

[0013] A tea drying machine is provided, wherein a hot air device and a conveying device are provided in the drying machine, wherein the hot air device comprises a fan and the above-mentioned heating box, and the fan is arranged at the air inlet direction of the heating box. Specifically, the fan can be a centrifugal fan.

[0014] Furthermore, the conveying device includes several layers of conveyor belts arranged from top to bottom, and the conveying directions of the upper and lower adjacent conveyor belts are opposite. The conveying device also includes a feed elevator and a discharge hopper. The feed elevator is connected to the conveyor belt of the uppermost layer, and the discharge hopper is connected to the conveyor belt of the lowermost layer.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. Each electric heating tube of the utility model is sheathed with a metal tube with excellent thermal conductivity. The metal tube can be preferably made of stainless steel with excellent thermal conductivity. A temperature control space is formed between the metal tube and the electric heating tube, and cold air flows into the box from the air inlet of the box and the ventilation opening of the fixed plate. When the electric heating tube is powered on to heat the cold air, after the electric heating tube is preheated, the metal tube, as an excellent heat-conducting medium, conducts heat, improves the heat conduction efficiency, and makes the heating box temperature rise relatively fast; when the electric heating tube is powered off, the cold air blows on the surface of the metal tube, and does not directly exchange heat with the temperature control space in the metal tube, so the heat in the temperature control space is lost slowly, and the hot air in the temperature control space can only flow out and merge from the ventilation holes of the metal tube, making the cooling speed of the heating box relatively slow, thereby extending the power-off of the electric heating tube, thereby shortening the total power-on time, further reducing energy loss, and achieving energy saving and environmental protection.

[0017] 2. The utility model adopts fin-type electric heating tubes and stainless steel metal tubes. Among electric heating tubes of the same specification, the fin-type heat exchange area is larger and the heating speed is faster, which can make the power-on time of the electric heating tube relatively short.

[0018] 4. The electric heating tubes of the utility model are arranged in a matrix in the heating box. Each row is composed of a number of electric heating tubes arranged at intervals. The two adjacent rows of electric heating tubes are staggered, so that the contact area between the electric heating tubes and the air is larger. Under the same conditions, the heat transfer coefficient is relatively large, and better heating uniformity can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the front view of the heating box of the utility model.

[0020] Figure 2 for Figure 1 AA direction profile.

[0021] Figure 3 This is a front view of the air outlet of the heating box of the utility model.

[0022] Figure 4 It is a structural schematic diagram of the utility model tea drying machine.

[0023] Among them, the numbers in the figure are: box body 10, C-shaped plate 101, side plate 102, fixed plate 103, ventilation opening 1031, reverse air plate 104, air inlet 11, air outlet 12, electric heating tube 20, metal tube 21, ventilation hole 211, temperature control space 22, fan 31, conveyor belt 32, feed elevator 321, and discharge hopper 322. DETAILED DESCRIPTION

[0024] The specific implementation of the present utility model is described below with reference to the accompanying drawings.

[0025] Reference Figure 1 and Figure 2 A heating box, the box body 10 of the heating box is composed of two front and rear U-shaped plates 101 and two upper and lower side plates 102, the left and right ends of the box body 10 form an air outlet 12 and an air inlet 11, the opening directions of the two U-shaped plates 101 are arranged in back to back, and the openings of the U-shaped plates 101 are respectively provided with fixing plates 103 for fixing the electric heating tube 20, and one side of the air outlet 12 of the box body 10 is provided with an inverted air plate 104 for guiding hot air.

[0026] Reference Figure 1 and Figure 2 , a plurality of electric heating tubes 20 are arranged in the box body 10 of the heating box, and the two ends of the electric heating tubes 20 respectively pass through two U-shaped plates 101 and are fixedly connected to the fixing plate 103. Specifically, in this embodiment, bolts can be used to fix the U-shaped plate 101 and the fixing plate 103. At least one of the two fixing plates 103 is provided with a plurality of ventilation openings 1031, and the air outside the box body 10 can flow into the box body 10 from the ventilation openings 1031. Specifically, in this embodiment, the ventilation openings 1031 are preferably provided on only one of the fixing plates 103.

[0027] Reference Figure 1 and Figure 2 , each electric heating tube 20 is sheathed with a metal tube 21, and the two ends of the metal tube 21 pass through the two C-shaped plates 101 respectively and are fixedly connected to the two C-shaped plates 101. Specifically, the metal tube 21 and the C-shaped plates 101 of this embodiment are preferably welded and fixed. A temperature control space 22 is formed between the metal tube 21 and the electric heating tube 20. The electric heating tube 20 is arranged in a matrix in the box body 10. Specifically, in this embodiment, the electric heating tube 20 is composed of 10 rows arranged in a matrix, with 5 tubes arranged at intervals in each row. The two adjacent rows of electric heating tubes 20 are staggered, so that the metal tube 21 sheathed on the electric heating tube 20 has a larger contact area with the air, and the heat transfer coefficient is relatively large under the same conditions, which can achieve better heating uniformity.

[0028] Reference Figure 2 and Figure 3 The metal tube 21 is provided with ventilation holes 211 on the side facing the air outlet 12 of the box 10. Specifically, 7 ventilation holes 211 are provided on each metal tube 21 at intervals. Cold air flows into the box 10 from the air inlet 11 of the box 10 and the ventilation opening 1031 of the fixing plate 103. The electric heating tube 20 is powered on for heating, and the cold air is heated to hot air through heat exchange. The metal tube 21, as an excellent heat conducting medium, can transfer heat to the outer surface of the metal tube 21, that is, heat exchange with the air outside the temperature control space 22 in the heating box. The hot air in the temperature control space 22 flows out from the ventilation holes 211 on the metal tube 21, merges with the hot air in the box 10, and then flows out from the air outlet 12 of the box 10, and flows along the guiding direction of the reverse air plate 104. Specifically, the electric heating tube 20 is a fin-type heating tube, and the heat exchange area is larger under the same specifications, so that the air in the temperature-controlled space 22 heats up faster, so the power-on time of the electric heating tube 20 can be appropriately shortened.

[0029] Reference Figure 2 and Figure 3 When the electric heating tube 20 is disconnected from the power supply, cold air continues to enter the heating box body 10. Since the electric heating tube 20 is covered with a metal tube 21, the cold air does not directly contact the electric heating tube 20 for heat exchange, so it can slow down the cooling rate of the electric heating tube 20 and the air in the temperature control space 22. The residual heat on the surface of the metal tube 21 can continue to exchange heat with the cold air in the box body 10, so that the overall cooling rate of the heating box is relatively slow, and the power-off time of the electric heating tube 20 can be appropriately extended. Therefore, the overall power-on time of the electric heating tube 20 can be relatively shortened, reducing energy consumption and saving environmental protection. After the interval time is up, the electric heating tube 20 is powered on again and continues to heat, and this cycle is repeated.

[0030] Reference Figure 1 and Figure 4A tea drying machine is provided with a hot air device and a conveying device. The hot air device includes a fan 31 and the above-mentioned heating box. Specifically, the fan 31 of this embodiment is preferably a centrifugal fan. The fan 31 is arranged in the direction of the air inlet 11 to provide cold air to the heating box. The reverse air plate 104 on the heating box guides the flow direction of the hot air flowing out of the heating box. The conveying device is arranged in the direction guided by the reverse air plate 104 of the box body 10, and the conveying device includes several layers of conveyor belts 32 arranged from top to bottom, and also includes a feed elevator 321 and a discharge hopper 322. The feed elevator 321 is connected to the conveyor belt 32 of the uppermost layer, and the discharge hopper 322 is connected to the conveyor belt 32 of the lowermost layer. When in use, the fan 31 is turned on to supply air, and the electric heating tube 20 in the heating box is energized for heating at intervals, and the hot air flows out from the air outlet 12 of the heating box, and flows to the conveyor belt 32 along the direction guided by the reverse wind plate 104. The material is loaded from the feed elevator 321 and transported to the hot air along the direction of the conveyor belt 32. The hot air performs heat exchange and drying on the material, and the material is then transported to the discharge hopper 322 along the conveyor belt 32 for collection. Specifically, the material in this embodiment is tea.

[0031] The above is only a specific implementation method of the utility model, but the design concept of the utility model is not limited to this. Any non-substantial changes to the utility model using this concept shall be deemed as an infringement of the protection scope of the utility model.

Claims

1. A heating box, comprising a box body and a plurality of electric heating tubes arranged in the box body, wherein two sides of the box body are respectively provided with an air inlet and an air outlet, characterized in that: Each of the electric heating tubes is sheathed with a metal tube, and a temperature control space is formed between the metal tube and the electric heating tube.

2. A heating box according to claim 1, characterized in that: The box body is composed of two front and rear U-shaped plates and two upper and lower side plates. The left and right ends of the box body form the air outlet and the air inlet. The opening directions of the two U-shaped plates are arranged in back to back. Fixed plates for fixing the electric heating tubes are respectively arranged in the openings of the U-shaped plates. A reverse air plate for guiding hot air is arranged on one side of the air outlet of the box body.

3. A heating box according to claim 2, characterized in that: The two ends of the electric heating tube pass through two C-shaped plates respectively and are fixedly connected to the fixing plate; the two ends of the metal tube pass through two C-shaped plates respectively and are fixedly connected to the C-shaped plates.

4. A heating box according to claim 3, characterized in that: At least one of the two fixing plates is provided with a plurality of ventilation openings.

5. A heating box according to any one of claims 1 or 4, characterized in that: The metal tube is provided with a plurality of ventilation holes facing the air outlet.

6. A heating box according to claim 1, characterized in that: The electric heating tubes are arranged in a matrix of several rows in the box, each row is composed of several electric heating tubes arranged at intervals, and two adjacent rows of electric heating tubes are arranged in a staggered manner.

7. A heating box according to claim 1, characterized in that: The electric heating tube is a fin-type heating tube.

8. A heating box according to claim 1, characterized in that: The metal tube is made of stainless steel.

9. A tea drying machine, characterized in that: The dryer is provided with a hot air device, which includes a fan and a heating box as described in any one of claims 1 to 8, and the fan is arranged in the direction of the air inlet.

10. A tea drying machine according to claim 9, characterized in that: The dryer is also provided with a conveying device for conveying tea leaves, which includes several layers of conveyor belts arranged from top to bottom, and the conveying directions of the upper and lower adjacent conveyor belts are opposite. The conveying device also includes a feed elevator and a discharge hopper. The feed elevator is connected to the conveyor belt of the uppermost layer, and the discharge hopper is connected to the conveyor belt of the lowermost layer.

Images