Hot air auxiliary circulation device and microwave drying equipment

Abstract

The invention relates to a hot air auxiliary circulating device which is used for microwave drying equipment and comprises an air inlet pipe, an air outlet pipe, an air outlet pipe, a hot air inlet pipe and a hot air outlet pipe, one end of the air inlet pipe is communicated with a microwave cavity of the microwave drying equipment, and the other end of the air inlet pipe is connected with a hot air dryer; the air outlet pipe is arranged at the upper part of the microwave drying equipment; the air outlet pipe is communicated with a microwave cavity of the microwave drying equipment; and the air inlet pipe and the air outlet pipe are oppositely arranged. According to the hot air auxiliary circulation device, hot air is introduced into the microwave cavity through the hot air dryer, materials can be rapidly heated, water evaporation is promoted, and the drying efficiency is improved through cooperation of microwave drying and hot air drying. And hot air in the microwave cavity is efficiently recycled through the outer circulation system, so that the energy consumption of the equipment is effectively reduced while the drying efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave drying, in particular to a hot air auxiliary circulation device and microwave drying equipment. Background Art

[0002] Existing microwave drying equipment for foundry sand cores uses a high-power magnetron as its core component, generating high-frequency electromagnetic waves. After being dip-coated, the sand cores are placed in a sealed microwave cavity, where they absorb electromagnetic energy, causing the water molecules within them to evaporate. The microwave drying equipment uses exhaust fans on both sides of the cavity to promptly expel the evaporated water vapor, completing the drying process.

[0003] Current equipment, which directly draws in cold air for exhaust, has significant technical flaws. Especially when processing large sand cores or using large microwave cavities, the continuous introduction of large volumes of cool air creates an intense heat exchange with the high-temperature environment within the cavity. This counteraction severely weakens the microwave's ability to heat the sand core's internal moisture, significantly extending the drying cycle and dramatically increasing the equipment's operating energy consumption. This not only significantly reduces production efficiency but also results in significant energy loss, resulting in both time and energy costs in actual production. Summary of the Invention

[0004] Based on this, it is necessary to provide a hot air assisted circulation device and microwave drying equipment for the above technical problems.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions:

[0006] An embodiment of the present invention discloses a hot air assisted circulation device for microwave drying equipment, the hot air assisted circulation device comprising: an air inlet and outlet duct, arranged at the lower part of the microwave drying equipment; one end of the air inlet duct is connected to the microwave cavity of the microwave drying equipment, and the other end of the air inlet duct is connected to a hot air dryer; an air outlet duct, arranged at the upper part of the microwave drying equipment; the air outlet duct is connected to the microwave cavity of the microwave drying equipment; the air inlet duct and the air outlet duct are arranged opposite to each other.

[0007] In one embodiment, the hot air assisted circulation device also includes a three-way reversing valve, an exhaust pipe and a circulation pipe, the air inlet of the three-way reversing valve is connected to the air outlet pipe; the first air outlet of the three-way reversing valve is connected to the exhaust pipe; one end of the circulation pipe is connected to the second air outlet of the three-way reversing valve, and the other end is arranged at the lower part of the microwave drying equipment and is connected to the microwave cavity of the microwave drying equipment.

[0008] In one embodiment, the air outlet duct is provided with an exhaust fan, and the exhaust volume of the exhaust fan matches the air intake volume of the microwave cavity.

[0009] In one embodiment, the circulation pipe is provided with a filtering unit.

[0010] In one embodiment, the filter unit is an air-water separator.

[0011] In one embodiment, the circulation pipe is provided with a detection unit, and the detection unit is provided between the filter unit and the three-way reversing valve.

[0012] In one embodiment, the detection unit includes a temperature detection element and a humidity detection element.

[0013] In one embodiment, the hot air auxiliary circulation device further includes a control system, and the control system is connected to the hot air dryer and the three-way reversing valve.

[0014] In one embodiment, the hot air temperature output by the hot air dryer is 150°C to 200°C.

[0015] In a second aspect, an embodiment of the present invention further discloses a microwave drying device provided with the hot air assisted circulation device according to any one of claims 1 to 8.

[0016] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0017] The hot air auxiliary circulation device disclosed in this invention for microwave drying equipment uses a hot air dryer to introduce hot air into the microwave cavity, rapidly heating the material and promoting moisture evaporation. The combined effects of microwave and hot air drying improve drying efficiency. The hot air within the microwave cavity is efficiently recycled through an external circulation system, improving drying efficiency while effectively reducing equipment energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a hot air assisted circulation device disclosed in an embodiment of the present invention;

[0019] Description of reference numerals:

[0020] 10-microwave cavity, 11-tray, 12-sand core; 21-hot air dryer, 22-air inlet pipe; 30-air outlet pipe, 40-three-way reversing valve, 50-exhaust pipe; 60-circulation pipe, 61-detection unit, 62-filtration unit, 70-exhaust fan. DETAILED DESCRIPTION

[0021] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present disclosure.

[0022] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "left," "right," "top," "bottom," "bottom end," "top end," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] The embodiment of the present invention discloses a hot air auxiliary circulation device, such as Figure 1 As shown, the disclosed hot air-assisted circulation device is connected to a microwave drying device to achieve hot air drying combined with microwave drying, improve drying efficiency, and reduce energy consumption. The hot air-assisted circulation device disclosed in this embodiment of the present invention includes a hot air dryer 21, an air inlet duct 22, and an air outlet duct 30. The hot air dryer 21 is disposed outside the microwave cavity 10 and communicates with the microwave cavity 10 via the air inlet duct 22. The air inlet duct 22 is connected to the lower portion of one side of the microwave cavity 10 and inputs the hot air generated by the hot air dryer 21 into the microwave cavity 10 to assist in heating the sand core 12 on the tray 11 within the microwave cavity 10. The air outlet duct 30 is connected to the upper portion of the other side of the microwave cavity 10, and the hot air in the upper portion of the microwave cavity 10 can be discharged through the air outlet duct 30. The air inlet duct 22 and the air outlet duct 30 are respectively disposed on opposite sides of the microwave cavity 10, so that the heat output by the hot air dryer 21 can be distributed throughout the microwave cavity 10.

[0025] The hot air dryer 21 preferably outputs hot air at a temperature of 150°C to 200°C.

[0026] Furthermore, to increase the exhaust volume of the air outlet duct 30, the air outlet duct 30 may be provided with an exhaust fan 70. The exhaust volume of the exhaust fan 70 should match the air intake volume of the microwave cavity 10 to prevent excessive or insufficient pressure in the microwave cavity 10. Of course, the exhaust fan 70 may be provided at the head end, the end end, or the middle portion of the air outlet duct 30, and this is not specifically limited in the present embodiment.

[0027] In the embodiment disclosed in the present invention, the hot air discharged from the air outlet duct 30 can be re-input into the microwave cavity 10 in an internal circulation manner, or can be directly discharged to the outside in an external exhaust manner. Specifically, the hot air auxiliary circulation device can also include a three-way reversing valve 40, an exhaust duct 50 and a circulation duct 60. The three-way reversing valve 40 is provided with an air inlet, a first air outlet and a second air outlet. In the first state, the air inlet is connected to the first air outlet; in the second state, the air inlet is connected to the second air outlet. In addition, the air outlet duct 30 is connected to the air inlet of the three-way reversing valve 40, the exhaust duct 50 is connected to the first air outlet of the three-way reversing valve 40, and the circulation duct 60 is connected to the second air outlet of the three-way reversing valve 40. The circulation duct 60 includes a vertical pipe and a horizontal pipe connected in sequence, wherein the outer end of the vertical pipe is connected to the second air outlet of the three-way reversing valve 40, and the outer end of the horizontal pipe is connected to the lower part of the microwave cavity 10. When the three-way reversing valve 40 is in the first state, the hot air from the air outlet pipe 30 is discharged to the outside through the exhaust pipe 50; when the three-way reversing valve 40 is in the second state, the hot air from the air outlet pipe 30 is re-input into the microwave cavity 10 in an internal circulation manner through the circulation pipe 60.

[0028] When the microwave drying equipment starts drying, the hot air dryer 21 starts simultaneously to input hot air into the microwave cavity 10. The three-way reversing valve 40 switches to the second state, and the hot air discharged from the air outlet pipe 30 is re-introduced into the microwave cavity 10 through the circulation pipe 60 in an internal circulation manner. When the internal circulation reaches a preset time, the three-way reversing valve 40 switches to the first state, and the hot air with adsorbed water vapor in the air outlet pipe 30 is discharged to the outside through the exhaust pipe 50, thereby reducing the humidity in the microwave cavity 10.

[0029] Furthermore, a detection unit 61 is provided in the middle of the vertical pipe. This detection unit 61 may include temperature and humidity detection components for detecting the temperature and humidity of the internally circulating hot air. The preset time for the internal circulation can be set based on the measurement values of the detection unit 61. When the temperature of the internally circulating hot air falls below the specified value, or the humidity rises above the specified value, indicating that the internal circulation time has expired, the three-way reversing valve 40 switches to the first state, and the hot air with adsorbed water vapor in the outlet pipe 30 is discharged to the outside through the exhaust pipe 50.

[0030] Furthermore, a filter unit 62, such as a gas-water separator, may be provided in the middle of the transverse tube. Thus, when the internal circulation reaches a preset time, i.e., when the measurement value of the detection unit 61 indicates that the humidity of the internal circulating hot air is higher than the standard value, there is no need to switch the three-way reversing valve 40 to the first state. The three-way reversing valve 40 remains in the second state, and the filter unit 62 is activated to filter the moisture from the internal circulating hot air with a humidity value higher than the standard value. After filtration, the hot air still maintains low humidity and high temperature and is circulated back into the microwave cavity, further improving the recycling rate of the hot air, improving the drying efficiency, and reducing the energy efficiency of the equipment.

[0031] In the embodiments disclosed herein, the hot air-assisted circulation device further includes a control system, such as a PLC controller. The control system is connected to the hot air dryer 21, the three-way reversing valve 40, the detection unit 61, the filter unit 62, and the exhaust fan 70. The control system can control the start and stop of the hot air dryer 21 and the exhaust fan 70, as well as the air volume. The control system can also control the reversing of the three-way reversing valve 40 and the start and stop of the filter unit 62 based on measurement data fed back by the detection unit 61. Of course, the hot air-assisted circulation device can also share a control system with the microwave drying equipment, and this embodiment of the present invention does not impose specific limitations on this.

[0032] In a second aspect, an embodiment of the present invention further discloses a microwave drying device, which is provided with the hot air auxiliary circulation device described in any of the above embodiments.

[0033] When the microwave drying equipment starts drying, the hot air dryer 21 starts simultaneously to input hot air into the microwave cavity 10. The three-way reversing valve 40 switches to the second state, and the hot air discharged from the air outlet pipe 30 is re-introduced into the microwave cavity 10 through the circulation pipe 60 in an internal circulation manner. When the internal circulation reaches a preset time, the three-way reversing valve 40 switches to the first state, and the hot air with adsorbed water vapor in the air outlet pipe 30 is discharged to the outside through the exhaust pipe 50, thereby reducing the humidity in the microwave cavity 10.

[0034] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A hot air assisted circulation device, characterized in that: For microwave drying equipment, the hot air auxiliary circulation device includes: An air inlet pipe is provided at the lower part of the microwave drying equipment; one end of the air inlet pipe is connected to the microwave cavity of the microwave drying equipment, and the other end of the air inlet pipe is connected to a hot air dryer; An air outlet pipe is provided on the upper part of the microwave drying equipment; the air outlet pipe is connected to the microwave cavity of the microwave drying equipment; The air inlet pipe and the air outlet pipe are arranged opposite to each other.

2. The hot air assisted circulation device according to claim 1, characterized in that: It also includes a three-way reversing valve, an exhaust pipe and a circulation pipe, wherein the air inlet of the three-way reversing valve is connected to the air outlet pipe; the first air outlet of the three-way reversing valve is connected to the exhaust pipe; One end of the circulation pipe is connected to the second air outlet of the three-way reversing valve, and the other end is arranged at the lower part of the microwave drying equipment and communicated with the microwave cavity of the microwave drying equipment.

3. The hot air assisted circulation device according to claim 2, characterized in that: The air outlet pipe is provided with an exhaust fan, and the exhaust volume of the exhaust fan matches the air intake volume of the microwave cavity.

4. The hot air assisted circulation device according to claim 2, characterized in that: The circulation pipe is provided with a filtering unit.

5. The hot air assisted circulation device according to claim 4, characterized in that: The filtering unit is a gas-water separator.

6. The hot air assisted circulation device according to claim 4, characterized in that: The circulation pipe is provided with a detection unit, and the detection unit is arranged between the filter unit and the three-way reversing valve.

7. The hot air assisted circulation device according to claim 6, characterized in that: The detection unit includes a temperature detection component and a humidity detection component.

8. The hot air assisted circulation device according to claim 2, characterized in that: It also includes a control system, which is connected to the hot air dryer and the three-way reversing valve.

9. The hot air assisted circulation device according to claim 1, characterized in that: The hot air temperature output by the hot air dryer is 150° C. to 200° C.

10. A microwave drying device, characterized in that: A hot air assisted circulation device according to any one of claims 1 to 8 is provided.

Images