A ceramic shell drying apparatus, system and method for casting

Abstract

In order to solve the problems in the prior art, the present application provides a ceramic shell drying device, system and method for casting. The ceramic shell drying device for casting comprises a drying cavity, a blowing cavity and an equipment cabin which are isolated from each other. An air inlet is formed in the side wall of the drying cavity, and the air inlet is filtered by a filtering mechanism. A condensation dryer is arranged in the drying cavity and close to the air inlet. A heater is arranged on the partition plate between the drying cavity and the blowing cavity, and the airflow between the drying cavity and the blowing cavity is communicated through the heater. An air blower is installed on the side wall of the blowing cavity to blow the gas in the blowing cavity. The system comprises the ceramic shell drying device for casting, a humidifier and various sensors. The method comprises special temperature and humidity control when the surface layer is dried. The present application solves the problems of ice formation and cleaning of the ceramic shell drying device for casting, and overcomes the problem of poor frequency of the existing large-scale ceramic shell drying device.

Description

Technical Field

[0001] This invention relates to the field of precision casting technology, specifically to a ceramic shell drying device, system, and method for casting. Background Technology

[0002] Lost-wax casting is currently the most commonly used precision casting method. This method first creates a hollow model of the desired product using a wax mold, then covers it with ceramic material to form a monolithic shell. Subsequently, the wax mold is melted and poured out by heating, leaving a cavity. Metal is then poured into the ceramic shell, and after the metal cools and solidifies, the final product is obtained. The advantages of lost-wax casting are its ability to produce complex structures and high-precision parts, and its suitability for casting various metal materials. However, it places high demands on the manufacturing of the ceramic shell; insufficient support, inadequate precision, or surface cracks in the ceramic shell can all affect the accuracy of the casting.

[0003] Current technology generally uses vacuum rapid dryers for drying ceramic shells. Its advantages include fast drying speed and high-quality shells. However, due to the limited volume of the drying chamber, the number of ceramic shells that can be dried per batch is limited. Therefore, large-scale casting companies still use natural drying in relatively high-temperature, low-humidity drying chambers. Although this method takes longer per batch, it significantly increases the number of ceramic shells that can be dried, and the size limitations are much less than with vacuum rapid dryers. In this method, the drying device is the main core equipment.

[0004] Existing drying equipment typically uses a radiator to condense and dry air flowing into the drying chamber. The condensed and dried air is then heated to the target temperature by a heater before being blown into the drying chamber. This allows for control of the ambient temperature and humidity within the drying chamber, achieving the drying of the ceramic shell. However, most existing drying equipment uses semi-automatic cleaning methods, such as timed cleaning of the radiator, or manual cleaning based on judgment. This often results in problems of untimely or excessive cleaning. Untimely cleaning severely affects the condensation and drying efficiency of the radiator, impacts ventilation, and leads to increased power consumption by the blower or radiator compressor, among other issues. Excessive cleaning wastes water and electricity.

[0005] Furthermore, existing drying equipment cannot effectively solve the problem of condenser icing, which leads to a series of problems, including:

[0006] 1. It obstructs airflow, causing the blower to need to operate at higher power to ensure the air volume.

[0007] 2. If the refrigerant in the radiator cannot absorb enough heat, the cooling effect will decrease, affecting the cooling and dehumidification effect, or causing the compressor to operate at higher power.

[0008] 3. If ice is not removed in time, it will gradually accumulate. On the one hand, it will cause additional stress to the cooling pipes due to the expansion of the ice. On the other hand, the accumulated ice will cause the pipes to bear more pressure (the weight of the ice itself), thus affecting the service life of the pipes. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a ceramic shell drying device for casting, comprising a drying chamber, a blower chamber, and an equipment compartment that are isolated from each other. An air inlet is provided on the side wall of the drying chamber, and the incoming air is filtered by a filtration mechanism. A condenser dryer is installed inside the drying chamber near the air inlet. A heater is installed on the partition between the drying chamber and the blower chamber, and the airflow between the two chambers is connected through the heater. A blower is installed on the side wall of the blower chamber to expel the gas inside.

[0010] The condenser dryer includes: a compressor, a first tubular heat exchanger, an expansion valve, and a radiator arranged in a pipe configuration. The radiator is arranged along the cross-sectional direction of the main airflow direction inside the drying chamber.

[0011] The outlet end of the compressor is connected to the inlet end of the first tubular heat exchanger, the outlet end of the first tubular heat exchanger is connected to the inlet end of the expansion valve, the outlet end of the expansion valve is connected to the inlet end of the radiator, and the outlet end of the radiator is connected to the inlet end of the compressor.

[0012] The operation of the condenser dryer, heater, and blower is controlled by a control system.

[0013] Furthermore, the filtration mechanism is a 250-400 mesh felt filter or a metal filter.

[0014] Furthermore, the inlet end of the heat pipe of the first tubular heat exchanger is connected to the outlet end of the compressor via a first connecting pipe, and the outlet end of the heat pipe is connected to the inlet end of the expansion valve via a second connecting pipe. The coolant inlet end of the first tubular heat exchanger is connected to an external liquid supply device via a third connecting pipe, and the coolant outlet end is connected to an external liquid storage device via a fourth connecting pipe. A first booster pump is installed on the third connecting pipe.

[0015] Furthermore, the external liquid supply device and the external liquid storage device constitute a first liquid storage tank, the third connecting pipe is connected to the bottom of the first liquid storage tank, and the fourth connecting pipe is connected to the top of the first liquid storage tank. The first liquid storage tank is installed inside the equipment compartment or outside the casting ceramic shell drying device.

[0016] Furthermore, a first three-way valve is provided between the first booster pump and the first tubular heat exchanger. The inlet end of the first three-way valve is connected to the outlet end of the first booster pump, one outlet end is connected to the fourth connecting pipe, and the other outlet end is connected to the coolant inlet end of the first tubular heat exchanger.

[0017] Furthermore, the first three-way valve is an electrically controlled three-way valve, and the control signal receiving end of the first three-way valve is connected to the control system signal. An ambient temperature sensor is installed outside the casting ceramic shell drying device. The ambient temperature sensor sends the external ambient temperature of the casting ceramic shell drying device to the control system in real time. The control system controls the flow ratio between the two passages of the first three-way valve based on the temperature information received from the ambient temperature sensor.

[0018] Furthermore, a first electronic thermometer is provided at the inlet end of the expansion valve. The control system receives the temperature information Y from the first electronic thermometer in real time and makes the following judgments:

[0019] When Y∈U, the flow ratio between the two passages of the first three-way valve is maintained.

[0020] when If Y is greater than Tmax, then the first three-way valve is controlled to increase the flow rate to the first tubular heat exchanger.

[0021] when If Y is less than Tmin, then control the first three-way valve to reduce the flow rate to the first tubular heat exchanger.

[0022] U is a preset temperature range, Tmax is the maximum value of U, and Tmin is the minimum value of U.

[0023] Furthermore, a second tubular heat exchanger (105) is provided between the first tubular heat exchanger and the expansion valve.

[0024] The second tubular heat exchanger includes heat dissipation pipes. The inlet end of the heat dissipation pipes is connected to the outlet end of the first tubular heat exchanger through a fifth connecting pipe, and the outlet end of the heat dissipation pipes is connected to the inlet end of the expansion valve through a sixth connecting pipe.

[0025] Furthermore, the second tubular heat exchanger also includes: heat exchange tubes, which are arranged close to the heat dissipation tubes.

[0026] A second three-way valve is provided between the compressor and the first tubular heat exchanger. The inlet end of the second three-way valve is connected to the outlet end of the compressor, one outlet end is connected to the inlet end of the first tubular heat exchanger, and the other outlet end is connected to the inlet end of the heat exchanger tubes through a seventh connecting pipe. The outlet end of the heat exchanger tubes is connected to the inlet end of the first tubular heat exchanger through an eighth connecting pipe.

[0027] Furthermore, the second three-way valve is an electrically controlled three-way valve, and its control signal receiving end is connected to the control system signal. An ambient temperature sensor is installed outside the casting ceramic shell drying device. This sensor transmits the ambient temperature outside the device to the control system in real time. The control system controls the flow ratio between the two passages of the second three-way valve based on the temperature information received from the sensor.

[0028] Furthermore, the partition is equipped with a cleaning system at the cold radiator location, the cleaning system including: a spray plate disposed on top of the cold radiator and covering the cold radiator, and a support drain plate disposed at the bottom of the cold radiator.

[0029] The spray plate has several spray holes on the side facing the radiator, and all of the spray holes are connected to a water washing pipe. The water washing pipe is connected to a liquid supply pipe via a second booster pump, and the liquid supply pipe is connected to a cleaning water storage mechanism.

[0030] The supporting drain plate has a liquid collection tank at the position of the radiator, and the bottom of the radiator is fixed to the supporting drain plate on both sides of the liquid collection tank. The bottom of the liquid collection tank is connected to an external water treatment mechanism through a drain pipe.

[0031] The control signal input terminal of the second booster pump is connected to the control system signal, and the control system starts the second booster pump according to the analysis results of the washing and cooling radiator analysis.

[0032] Furthermore, a first anemometer and a second anemometer are respectively installed on both sides of the cold air radiator along the airflow direction inside the drying chamber.

[0033] The analysis of the cold air radiator includes: velocity difference analysis, which includes:

[0034] Step 1.1 Receive the first wind speed S1 from the first anemometer and the second wind speed S2 from the second anemometer in real time.

[0035] Step 1.2 Calculate the wind speed difference C = S1 - S2.

[0036] Step 1.3 When C≥K1, it is determined that the cold radiator needs to be washed, and the second booster pump is started. K1 is a preset flow rate difference threshold.

[0037] Furthermore, a second electronic thermometer is provided at the outlet end of the radiator to detect the temperature of the refrigerant at the end of the radiator and send the detection result to the control system.

[0038] The analysis of the radiator includes: radiator temperature analysis, which includes:

[0039] Step 2.1 Receive temperature information T from the second electronic thermometer in real time.

[0040] Step 2.2 When T≤K2, it is determined that the radiator needs to be cleaned, and the second booster pump (502) is started. K2 is a preset temperature threshold.

[0041] Furthermore, the compressor is equipped with an electronic barometer at its inlet end to detect the refrigerant pressure at the compressor inlet end and send the detection result to the control system.

[0042] The analysis of the radiator cooling system includes: refrigerant pressure analysis, which includes:

[0043] Step 3.1 Receive pressure information P from the electronic barometer in real time.

[0044] Step 3.2 When P≤K3, it is determined that the cold radiator needs to be cleaned, and the second booster pump is started. K3 is a preset pressure threshold.

[0045] Furthermore, the radiator washing analysis includes: timing analysis, which includes:

[0046] Step 4.1 Obtain the current time information N in real time.

[0047] Step 4.2 When N∈M, it is determined that the cold air radiator needs to be washed, and the second booster pump is started. M is a preset set of time points.

[0048] Furthermore, several jet nozzles are arranged along one side of the radiator. The jet nozzles are angled downwards towards the radiator. All of the jet nozzles are connected to the output end of the air compressor.

[0049] At this time, the control system starts the second booster pump for a first preset time and then shuts it down, and starts the air compressor for a second preset time and then shuts it down.

[0050] Furthermore, the present invention provides a ceramic shell drying system for casting, comprising: at least one of the above-mentioned ceramic shell drying devices for casting installed in a drying area, at least one humidifier, several temperature sensors and humidity sensors located at different positions, and a drying control system that is signal-connected to the ceramic shell drying device for casting, the humidifier, the temperature sensors and the humidity sensors.

[0051] The drying control system receives temperature information from the temperature sensor and humidity information from the humidity sensor, and controls the temperature and humidity within the drying area according to preset settings for the humidifier and ceramic shell drying device.

[0052] Furthermore, the drying area is a drying chamber or the drying cavity of a drying device.

[0053] In addition, the present invention also provides a method for drying ceramic shells, which uses the above-mentioned casting ceramic shell drying system to dry the ceramic shells to be dried.

[0054] Furthermore, during the drying of the ceramic shell, the following steps are performed:

[0055] When drying the surface layer of the ceramic shell, the humidity in the drying area should be controlled at 70-90%, and the temperature at 20-24℃.

[0056] When drying the second layer of the ceramic shell, the humidity in the drying area should be controlled at 50-70%, and the temperature at 22-26℃.

[0057] When drying the third layer of the ceramic shell, the humidity in the drying area should be controlled at 40-50%, and the temperature at 22-26℃.

[0058] When drying the fourth and subsequent layers of the ceramic shell, the humidity in the drying area should be controlled at 30-40%, and the temperature at 22-26℃.

[0059] Furthermore, when drying the surface layer or the second layer of the ceramic shell, the airflow speed in the drying area is controlled so that the temperature difference between the dry bulb and the wet bulb does not exceed 2°C.

[0060] This invention has at least one of the following beneficial effects:

[0061] 1. This invention changes the existing cooling method for high-temperature, high-pressure refrigerant liquids. On the one hand, the refrigerant pipes can be installed entirely inside the device, effectively reducing the refrigerant pipe length and significantly reducing the limitations on equipment installation location. On the other hand, it allows the temperature of the refrigerant entering the radiator to be relatively stable, with less influence from ambient temperature, thereby stabilizing the radiator temperature and significantly improving the stability of condensation and drying.

[0062] 2. The ceramic shell drying device of the present invention can effectively prevent the problem of icing on the cold plate, thereby solving the problem of unstable drying effect caused by icing on the cold plate.

[0063] 3. This invention employs a self-designed method for identifying and controlling radiator cleaning, which enables automatic cleaning control of the radiator and prevents radiator from freezing or accumulating excessive dust and debris.

[0064] 4. The present invention improves the structure of the condenser dryer, thereby making the temperature of the refrigerant entering the radiator tend to be within the control range, thus effectively avoiding the problem of radiator freezing due to excessively low refrigerant temperature, and reducing the energy consumption of heating the radiator in winter.

[0065] 5. The present invention, through an improved method for drying ceramic shells, can significantly improve the yield of dried ceramic shells for large-scale production. Attached Figure Description

[0066] Figure 1This is a schematic diagram of the structure of the ceramic shell drying device for casting according to the present invention;

[0067] Figure 2 This is a schematic diagram of the structure of a condenser dryer according to the present invention;

[0068] Figure 3 This is a schematic diagram of the structure of the first tubular heat exchanger of the present invention;

[0069] Figure 4 This is a schematic diagram of another condenser dryer according to the present invention;

[0070] Figure 5 This is a schematic diagram of another condenser dryer according to the present invention;

[0071] Figure 6 This is a schematic diagram of the structure of the second tubular heat exchanger of the present invention;

[0072] Figure 7 This is a schematic diagram of the cleaning system of the present invention;

[0073] Figure 8 This is a schematic diagram of the structure of the spray plate of the present invention;

[0074] Figure 9 This is a schematic diagram of the structure supporting the drainage plate of the present invention;

[0075] Figure 10 This is a schematic diagram showing the installation positions of the first and second anemometers of the present invention.

[0076] Figure 11 This is a schematic diagram of the ceramic shell drying system for casting according to the present invention;

[0077] In the picture:

[0078] 1. Condenser dryer; 101. Compressor; 102. First tubular heat exchanger; 1021. Fourth connecting pipe; 1022. Third connecting pipe; 1023. First connecting pipe; 1024. Second connecting pipe; 1025. First booster pump; 1026. First tee; 103. Expansion valve; 104. Radiator with tubular arrangement; 105. Second tubular heat exchanger; 1051. Heat dissipation tubes; 1052. Fifth connecting pipe; 1053. Sixth connecting pipe; 1054. Heat exchange tubes; 105 5. Eighth connecting pipe; 1056. Seventh connecting pipe; 106. Second three-way valve; 2. Heater; 3. Blower; 4. Partition; 5. Cleaning system; 501. Liquid supply pipe; 502. Second booster pump; 503. Water washing pipe; 504. Spray plate; 505. Support drain plate; 506. Liquid collection tank; 507. Drain pipe; 6. Filtration mechanism; 7. Jet nozzle; 8. First liquid storage tank; 9. Second anemometer; 10. First anemometer; 11. Drying chamber; 12. Blower chamber; 13. Equipment compartment. Detailed Implementation

[0079] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0080] Please note that the terms "above", "below", "left", "right", "top", "top", "bottom", "bottom", etc., used in this invention to describe positional relationships do not represent the absolute positional relationship between modules / components / assemblies / parts / components, but rather the relative positional relationship between modules / components / assemblies / parts / components.

[0081] Example 1

[0082] A ceramic shell drying device for casting, such as Figure 1 As shown, the system includes a drying chamber 11, a blower chamber 12, and an equipment compartment 13, which are isolated from each other. The drying chamber 11 has an air inlet on its side wall, and the incoming air is filtered by a filter mechanism 6. A condenser dryer 1 is installed inside the drying chamber 11 near the air inlet. A heater 2 is installed on the partition 4 between the drying chamber 11 and the blower chamber 12, and the airflow between the two chambers is connected through the heater 2. A blower 3 is installed on the side wall of the blower chamber 12 to expel the gas inside.

[0083] like Figure 2 As shown, the condenser dryer 1 includes: a compressor 101, a first tubular heat exchanger 102, an expansion valve 103, and a cooling radiator 104 arranged in a pipe configuration. The cooling radiator 104 is arranged along the cross-sectional direction of the main airflow direction inside the drying chamber 11.

[0084] The outlet end of the compressor 101 is connected to the inlet end of the first tubular heat exchanger 102, the outlet end of the first tubular heat exchanger 102 is connected to the inlet end of the expansion valve 103, the outlet end of the expansion valve 103 is connected to the inlet end of the radiator 104, and the outlet end of the radiator 104 is connected to the inlet end of the compressor 101.

[0085] The operation of the condenser dryer 1, heater 2, and blower 3 is controlled by the control system.

[0086] In the existing condenser dryer 1, the high-temperature, high-pressure refrigerant liquid generated by the compressor 101 is generally cooled by air cooling through a combination of heat dissipation pipes and a blower. This transforms the refrigerant entering the condenser 104 into a high-pressure, low-temperature refrigerant liquid. After passing through the expansion valve, the high-pressure, low-temperature refrigerant liquid transforms into a low-pressure, low-temperature refrigerant gas. During the transformation from liquid to gas, the refrigerant absorbs a large amount of heat from the environment, keeping the condenser 104 at a low temperature. At this time, moisture in the airflow passing through the condenser 104 condenses into water droplets on the pipe walls of the condenser 104, significantly reducing the moisture content of the airflow and achieving low-temperature drying of the airflow.

[0087] However, existing technologies that use heat dissipation pipes in conjunction with blowers for air cooling dissipate a large amount of heat directly into the environment surrounding the heat dissipation pipes. This necessitates that the heat dissipation pipes be installed outside the drying area, increasing the refrigerant pipe length, limiting the equipment's installation location, and wasting a significant amount of heat. Furthermore, this method is highly susceptible to ambient air temperature; high or low ambient temperatures significantly affect the refrigerant temperature entering the expansion valve 103, leading to temperature instability in the radiator 104. This, in turn, affects the stability of condensation drying and interferes with humidity control within the drying area.

[0088] Therefore, this invention changes the existing cooling method for high-temperature, high-pressure refrigerant liquids by employing a first tubular heat exchanger 102 to cool the liquid. This allows the refrigerant pipes to be installed entirely inside the device, effectively reducing the refrigerant pipe length and significantly minimizing limitations on equipment installation location. Furthermore, the tubular heat exchanger effectively controls the output refrigerant temperature, ensuring a relatively stable refrigerant temperature entering the radiator 104, less affected by ambient temperature. This results in a more stable temperature for the radiator 104, significantly improving the stability of condensation and drying.

[0089] Example 2

[0090] Based on the ceramic shell drying device for casting in Example 1, such as Figure 3 As shown, the inlet end of the heat pipe of the first tubular heat exchanger 102 is connected to the outlet end of the compressor 101 via a first connecting pipe 1023, and the outlet end of the heat pipe is connected to the inlet end of the expansion valve 103 via a second connecting pipe 1024. The coolant inlet end of the first tubular heat exchanger 102 is connected to an external liquid supply device via a third connecting pipe 1022, and the coolant outlet end is connected to an external liquid storage device via a fourth connecting pipe 1021. A first booster pump 1025 is provided on the third connecting pipe 1022.

[0091] This setup uses a first booster pump 1025 to pump the low-temperature heat exchange medium from the external liquid supply device into the first tubular heat exchanger 102, cooling the high-temperature, high-pressure refrigerant liquid. The high-temperature heat exchange medium, after heat exchange, enters the external liquid storage device through the fourth connecting pipe 1021. The third connecting pipe 1022 and the fourth connecting pipe 1021 can be flexible hoses or pipes connected by flexible hoses, depending on the requirements. The heat exchange medium can be one or more of existing heat exchange media, such as water, hot oil, ethylene glycol, or alcohol, depending on the requirements.

[0092] This setup allows the high-temperature heat exchange medium from the external liquid storage device to be introduced into other heat-requiring mechanisms for heat recovery and reuse, achieving effective utilization of heat energy and energy conservation.

[0093] Example 3

[0094] Based on the ceramic shell drying apparatus for casting in Example 2, such as Figure 3 As shown, the external liquid supply device and the external liquid storage device are a first liquid storage tank 8. The third connecting pipe 1022 is connected to the bottom of the first liquid storage tank 8, and the fourth connecting pipe 1021 is connected to the top of the first liquid storage tank 8. The first liquid storage tank 8 is installed inside the equipment compartment 13 or outside the casting ceramic shell drying device.

[0095] This configuration unifies the external liquid supply device and the external liquid storage device into the first liquid storage tank 8, so that the heat exchange medium after heat exchange is completed can be naturally cooled in the first liquid storage tank 8 before entering the first tubular heat exchanger 102 for heat exchange. This configuration can effectively shorten the tube length, making the structure of the entire device more compact, and at the same time, it can realize the recycling of the heat exchange medium.

[0096] Example 4

[0097] Based on the ceramic shell drying apparatus for casting in Example 2, such as Figure 3 As shown, a first three-way valve 1026 is provided between the first booster pump 1025 and the first tubular heat exchanger 102. The inlet end of the first three-way valve 1026 is connected to the outlet end of the first booster pump 1025, one outlet end is connected to the fourth connecting pipe 1021, and the other outlet end is connected to the coolant inlet end of the first tubular heat exchanger 102.

[0098] To ensure the refrigerant output from the first tube heat exchanger 102 remains within the target temperature range, the flow rate of the heat exchange medium entering the first tube heat exchanger 102 needs to be adjusted according to changes in ambient temperature. For example, in winter, when the external ambient temperature is low, the refrigerant cools down naturally and quickly during its flow through the pipes. Therefore, it is necessary to reduce the flow rate of the heat exchange medium in the first tube heat exchanger 102 to prevent the refrigerant temperature from becoming too low, which could lead to excessively low temperatures in the radiator 104 and cause pipe icing. Icing in the radiator 104 pipes can cause a series of problems, commonly including:

[0099] 4. It obstructs airflow, causing the blower to need to operate at higher power to ensure the air volume.

[0100] 5. If the refrigerant in the radiator cannot absorb enough heat, the cooling effect will decrease, affecting the cooling and dehumidification effect, or causing the compressor to operate at higher power.

[0101] 6. If ice is not removed in time, it will gradually accumulate. On the one hand, it will cause additional stress to the cooling pipes due to the expansion of the ice. On the other hand, the accumulated ice will cause the pipes to bear more pressure (the weight of the ice), thus affecting the service life of the pipes.

[0102] In summer, the external ambient temperature is high, and the refrigerant cools down slowly as it flows through the pipes. Therefore, it is necessary to increase the flow rate of the heat exchange medium in the first tubular heat exchanger 102 to avoid the refrigerant temperature from being too high, which would cause the temperature of the radiator 104 to be too high and result in poor condensation and drying.

[0103] Existing technologies commonly change the flow rate of the heat exchange medium in the first tubular heat exchanger 102 by altering the operating power of the first booster pump 1025. However, this method is problematic because frequent changes in the operating power of the first booster pump 1025 can easily lead to pump malfunctions, increasing maintenance costs. Furthermore, the change in flow rate caused by variations in the operating power of the first booster pump 1025 exhibits a certain lag, resulting in poor control accuracy. This invention achieves real-time, precise control of the flow rate of the heat exchange medium entering the first tubular heat exchanger 102 by introducing a first three-way valve 1026 into the flow loop of the heat exchange medium. This method not only adjusts the flow rate of the heat exchange medium entering the first tubular heat exchanger 102 by adjusting the ratio of the flow rate to the first tubular heat exchanger 102 and the flow rate to the fourth connecting pipe 1021, but also avoids problems caused by frequent changes in the operating power of the first booster pump 1025.

[0104] Example 5

[0105] Based on the casting ceramic shell drying device of Embodiment 4, the first three-way valve 1026 is an electrically controlled three-way valve, and the control signal receiving end of the first three-way valve 1026 is connected to the control system signal. An ambient temperature sensor is provided externally to the casting ceramic shell drying device. The ambient temperature sensor sends the external ambient temperature of the casting ceramic shell drying device to the control system in real time. The control system controls the flow ratio between the two passages of the first three-way valve 1026 based on the temperature information received from the ambient temperature sensor.

[0106] This method uses an ambient temperature sensor to detect the ambient temperature in real time, and then uses a control system to perform threshold comparison analysis and control the first three-way valve 1026 to adjust the flow ratio between the two passages according to the basic rules in Example 4, thereby achieving real-time automatic and precise control of the flow rate of the heat exchange medium entering the first tubular heat exchanger 102.

[0107] Example 6

[0108] Based on the casting ceramic shell drying device of Embodiment 5, the inlet end of the expansion valve 103 is equipped with a first electronic thermometer. The control system receives the temperature information Y from the first electronic thermometer in real time and makes the following judgments:

[0109] When Y∈U, the flow ratio between the two passages of the first three-way valve 1026 is maintained.

[0110] when If Y is greater than Tmax, then the first three-way valve 1026 is controlled to increase the flow rate to the first tubular heat exchanger 102.

[0111] when If Y is less than Tmin, then control the first three-way valve 1026 to reduce the flow rate to the first tubular heat exchanger 102.

[0112] U is a preset temperature range, Tmax is the maximum value of U, and Tmin is the minimum value of U.

[0113] This embodiment provides a threshold comparison analysis method, wherein: the preset temperature range U is a temperature range preset based on the surface area of ​​the radiator 104, generally between ±1℃ and ±2℃ of the preset target temperature, and the preset target temperature can be selected based on the specific surface area of ​​the radiator 104 and the ambient temperature, the purpose of which is to ensure that the refrigerant temperature of the radiator 104 is not lower than the preset minimum temperature, such as 1℃ or 0℃.

[0114] Taking a 104 radiator with a diameter of 2cm and a total length of 10 meters as an example, the target temperature can be preset to 23℃ in summer, at which time the temperature range can be 22℃-24℃. In winter, the target temperature can be preset to 25℃, at which time the temperature range can be 24℃-26℃.

[0115] Example 6

[0116] The ceramic shell drying device for casting based on the above embodiments, such as Figure 4 As shown, a second tubular heat exchanger 105 is provided between the first tubular heat exchanger 102 and the expansion valve 103.

[0117] The second tubular heat exchanger 105 includes a heat dissipation pipe 1051. The inlet end of the heat dissipation pipe 1051 is connected to the outlet end of the first tubular heat exchanger 102 through a fifth connecting pipe 1052. The outlet end of the heat dissipation pipe 1051 is connected to the inlet end of the expansion valve 103 through a sixth connecting pipe 1053.

[0118] Existing technologies primarily utilize heat dissipation pipes to naturally or force-cool the high-pressure, high-temperature refrigerant output from compressor 101 into a high-pressure, low-temperature refrigerant, allowing the refrigerant to absorb as much external heat as possible during its conversion to a low-pressure, low-temperature refrigerant in radiator 104. This invention uses the first tubular heat exchanger 102 in the above embodiment to perform the initial cooling of the high-pressure, high-temperature refrigerant. However, during use, it was found that even when using only the first tubular heat exchanger 102, while the refrigerant temperature output from it sometimes meets the temperature control requirements, the refrigerant still needs to pass through a section of tubing before entering expansion valve 103. Therefore, the refrigerant temperature entering expansion valve 103 fluctuates under the influence of the external ambient temperature, potentially no longer meeting the temperature control requirements. Furthermore, with continuous use of the ceramic shell dryer and the influence of the high-temperature external environment, the refrigerant temperature output from the first tubular heat exchanger 102 can exceed the temperature control upper limit significantly, leading to excessively high radiator 104 temperature and a significant reduction in dehumidification effect.

[0119] Therefore, the present invention provides a second tubular heat exchanger 105 near the expansion valve 103, and performs relatively accurate temperature control through the second tubular heat exchanger 105 so that the temperature of the refrigerant entering the expansion valve 103 meets the temperature control requirements.

[0120] Example 7

[0121] Based on the ceramic shell drying apparatus for casting in Example 6, such as Figure 5 and Figure 6 As shown, the second tubular heat exchanger 105 further includes a heat exchange tube 1054, which is arranged close to the heat dissipation tube 1051.

[0122] A second three-way valve 106 is provided between the compressor 101 and the first tubular heat exchanger 102. The inlet end of the second three-way valve 106 is connected to the outlet end of the compressor 101, one outlet end is connected to the inlet end of the first tubular heat exchanger 102, and the other outlet end is connected to the inlet end of the heat exchanger tube 1054 through a seventh connecting pipe 1056. The outlet end of the heat exchanger tube 1054 is connected to the inlet end of the first tubular heat exchanger 102 through an eighth connecting pipe 1055.

[0123] The second three-way valve 106 is an electrically controlled three-way valve, and its control signal receiving end is connected to the control system signal. An ambient temperature sensor is installed outside the casting ceramic shell drying device. This sensor transmits the ambient temperature outside the device to the control system in real time. The control system controls the flow ratio between the two passages of the second three-way valve 106 based on the temperature information received from the sensor.

[0124] When the ambient temperature is low, especially in northern regions where the ambient temperature may be below zero, the second tube heat exchanger 105 may need to heat the refrigerant to prevent the refrigerant at too low a temperature from entering the radiator 104.

[0125] Traditional heating methods typically involve resistance wire heating, hot air heating, or steam pipe heat exchange, but all of these methods suffer from high energy consumption. To address this, the present invention provides a more energy-efficient method for heating refrigerant. Specifically, a portion of the high-temperature, high-pressure refrigerant is diverted to the heat exchange pipe 1054 via a second three-way valve 106. The high-temperature, high-pressure refrigerant dissipates heat at the heat exchange pipe 1054, lowering its temperature while simultaneously heating the refrigerant flowing through the heat exchange pipe 1051. This achieves the heating effect on the refrigerant with over 90% less energy consumption compared to resistance wire heating, hot air heating, or steam pipe heat exchange.

[0126] Example 8

[0127] Based on the ceramic shell drying device for casting in Example 1, such as Figure 1 , Figure 7-9 As shown, the partition 4 is provided with a cleaning system 5 at the position of the cold radiator 104. The cleaning system 5 includes: a spray plate 504 disposed on the top of the cold radiator 104 and covering the cold radiator 104, and a support drain plate 505 disposed at the bottom of the cold radiator 104.

[0128] The spray plate 504 has several spray holes 506 on the side facing the radiator 104, and all of the spray holes 506 are connected to the water washing pipe 503. The water washing pipe 503 is connected to the liquid supply pipe 501 through the second booster pump 502, and the liquid supply pipe 501 is connected to the cleaning water storage mechanism.

[0129] The supporting drain plate 505 has a liquid collection tank 506 at the position of the cold radiator 104, and the bottom of the cold radiator 104 is fixedly mounted on the supporting drain plates 505 on both sides of the liquid collection tank 506. The bottom of the liquid collection tank 506 is connected to an external water treatment mechanism through a drain pipe 507.

[0130] The control signal input terminal of the second booster pump 502 is connected to the control system signal, and the control system controls the start of the second booster pump 502 according to the analysis results of the washing and cooling radiator analysis.

[0131] During operation, dust or debris may accumulate on the radiator 104, significantly increasing the difficulty of airflow and affecting the delivery of dry air to the target area. Existing technologies typically address this by periodically shutting down the radiator 104 for cleaning and maintenance. However, this periodic shutdown interrupts the drying process of the ceramic shell, impacting production efficiency. Furthermore, since dust or debris accumulation is an unpredictable process, cleaning may not be performed on time due to the timing not being reached, or there may be insufficient dust or debris accumulation during cleaning, resulting in unnecessary waste of production time.

[0132] Furthermore, during use, the radiator 104 may experience excessively low pipe wall temperatures due to external temperature or the absorption of its own refrigerant, leading to icing on the pipe wall. The hazards of icing in the radiator pipes are significant. Based on the analysis results of radiator cleaning, this invention can also forcefully flush away water droplets or thin ice layers that have condensed in the airflow on the radiator 104 pipe wall when necessary, thus preventing icing or ice accumulation on the radiator.

[0133] Example 9

[0134] Based on the ceramic shell drying apparatus for casting in Example 8, such as Figure 1 and Figure 10 As shown, a first anemometer 10 and a second anemometer 9 are respectively provided on both sides of the cold air duct 104 along the airflow direction in the drying chamber 11.

[0135] The analysis of the cold air radiator includes: velocity difference analysis, which includes:

[0136] Step 1.1 Receive the first wind speed S1 from the first anemometer 10 and the second wind speed S2 from the second anemometer 9 in real time.

[0137] Step 1.2 Calculate the wind speed difference C = S1 - S2.

[0138] Step 1.3 When C≥K1, it is determined that the cold radiator needs to be washed, and the second booster pump 502 is started. K1 is a preset flow rate difference threshold.

[0139] This method is the first type of cold radiator cleaning analysis method in this invention, which determines the smoothness of airflow through the cold radiator 104 by collecting the airflow velocity difference on both sides of the cold radiator 104. When C≥K1, it is considered that too much dust, impurities, and ice have adhered to the cold radiator 104, so a forced cold radiator cleaning action is required to remove the dust, impurities, and ice adhering to the surface of the cold radiator. K1 is a preset velocity difference threshold, which is generally set according to factors such as the size of the cold radiator, the density of the cold radiator pipeline, and the usage requirements of the ceramic shell drying device for casting.

[0140] Example 10

[0141] Based on the casting ceramic shell drying device of Embodiment 8, a second electronic thermometer is provided at the outlet end of the cold radiator 104 to detect the temperature of the refrigerant at the end of the cold radiator 104 and send the detection result to the control system.

[0142] The analysis of the radiator includes: radiator temperature analysis, which includes:

[0143] Step 2.1 Receive temperature information T from the second electronic thermometer in real time.

[0144] Step 2.2 When T≤K2, it is determined that the radiator needs to be cleaned, and the second booster pump 502 is started. K2 is a preset temperature threshold.

[0145] This method is the second type of radiator washing analysis method in the example of the present invention. This method mainly monitors the temperature of the refrigerant at the end of radiator 104. That is, when the temperature of the refrigerant at the end of radiator 104 is low, the present invention believes that the temperature inside the radiator 104 pipeline is low and there is a potential possibility of pipeline freezing. In order to avoid possible freezing of the radiator 104 pipeline, the pipeline surface is flushed by starting a forced radiator washing method. The water flow washes away the water droplets on the pipeline surface, thereby reducing the possibility of freezing on the pipeline surface.

[0146] K2 is a preset temperature threshold, which can generally be set to 0-5℃. The specific setting can be adjusted according to the local ambient temperature. For example, when the ambient temperature is high (e.g., 20℃), K2 can be set lower, such as 0℃ or 1℃. When the ambient temperature is low (e.g., -5℃), K2 can be set higher, such as 3℃ or 4℃.

[0147] Example 11

[0148] Based on the casting ceramic shell drying device of Embodiment 8, the inlet end of the compressor 101 is equipped with an electronic barometer for detecting the refrigerant pressure at the inlet end of the compressor 101 and sending the detection result to the control system.

[0149] The analysis of the radiator cooling system includes: refrigerant pressure analysis, which includes:

[0150] Step 3.1 Receive pressure information P from the electronic barometer in real time.

[0151] Step 3.2 When P≤K3, it is determined that the cold radiator needs to be cleaned, and the second booster pump 502 is started. K3 is a preset pressure threshold.

[0152] This method is the third type of radiator cleaning analysis method in the example of this invention. This method mainly monitors the refrigerant pressure at the inlet end of compressor 101. That is, when the refrigerant pressure at the inlet end of compressor 101 is low, this invention believes that the refrigerant has insufficient heat absorption at radiator 104. That is, radiator 104 may have problems with pipeline icing or excessive dust and debris on the pipeline surface. By starting the forced radiator cleaning method to flush the pipeline surface, the ice, dust and debris attached to the pipeline surface can be cleaned away.

[0153] K3 is the preset low-pressure threshold at the inlet of compressor 101, which is generally set with reference to the return gas pressure of compressor 101 when icing occurs on radiator 104.

[0154] Example 12

[0155] Based on the casting ceramic shell drying apparatus of Example 8, the analysis of the washing and cooling radiator includes: timed analysis, which includes:

[0156] Step 4.1 Obtain the current time information N in real time.

[0157] Step 4.2 When N∈M, it is determined that the cold air radiator needs to be washed, and the second booster pump 502 is started. M is a preset set of time points.

[0158] This method is the fourth type of cooling radiator analysis method in the example of this invention, and it adopts a timed control method that is currently more common.

[0159] This invention provides four exemplary methods for analyzing cold radiator cleaning. Each method can be used individually or in combination. The methods provided in Examples 9-11 can achieve automatic cleaning control of the cold radiator. That is, when there is a possibility of icing in the pipeline of the cold radiator 104, or when it has already iced or accumulated a lot of dust and debris, the cold radiator cleaning action is performed automatically, which effectively avoids the problems of timed cold radiator cleaning in the prior art.

[0160] Example 13

[0161] The ceramic shell drying device for casting based on the above embodiments, such as Figure 1As shown, several jet nozzles 7 are arranged along one side of the radiator 104. The jet nozzles 7 spray air at an angle downwards towards the radiator 104. All of the jet nozzles 7 are connected to the output end of the air compressor.

[0162] At this time, the control system starts the second booster pump 502 for a first preset time and then shuts it down, and starts the air compressor for a preset second time and then shuts it down.

[0163] The main purpose of the jet head 7 added to this invention is to blow away the water droplets remaining on the surface of the radiator 104 pipeline by outputting high-pressure airflow after the radiator is cleaned, thereby avoiding the possibility of icing on the pipeline surface due to excessive humidity caused by the radiator cleaning.

[0164] Example 14

[0165] A ceramic shell drying system for casting, such as Figure 11 As shown, it includes: at least one casting ceramic shell drying device of the above embodiment installed in the drying area, at least one humidifier, several temperature sensors and humidity sensors located at different positions, and a drying control system that is connected to the casting ceramic shell drying device, humidifier, temperature sensors and humidity sensors.

[0166] The drying control system receives temperature information from the temperature sensor and humidity information from the humidity sensor, and controls the temperature and humidity within the drying area according to preset settings for the humidifier and ceramic shell drying device.

[0167] The present invention provides a ceramic shell drying system for casting constructed using the ceramic shell drying device of the above embodiment. In this case, the ceramic shell drying device mainly serves to provide a drying airflow at a suitable temperature.

[0168] According to one embodiment of the present invention, the drying area is a drying chamber or a drying cavity of a drying device. That is, the drying area can be the area in a drying chamber used for large-scale drying where the ceramic shells to be dried are placed, or it can be a cavity in a ceramic shell dryer used to place the ceramic shells to be dried.

[0169] Compared to traditional large-scale drying methods that require the drying area to be in a low-humidity environment, this invention adds a humidifier to the drying area to adjust the humidity in the drying area in conjunction with the ceramic shell drying method of this invention, and to perform humidification treatment when necessary.

[0170] Example 15

[0171] A method for drying ceramic shells, using the ceramic shell drying system for casting shown in Example 14 to dry the ceramic shell to be dried.

[0172] When drying the ceramic shell, perform the following steps:

[0173] When drying the surface layer of the ceramic shell, the humidity in the drying area should be controlled at 70-90%, and the temperature at 20-24℃.

[0174] When drying the second layer of the ceramic shell, the humidity in the drying area should be controlled at 50-70%, and the temperature at 22-26℃.

[0175] When drying the third layer of the ceramic shell, the humidity in the drying area should be controlled at 40-50%, and the temperature at 22-26℃.

[0176] When drying the fourth and subsequent layers of the ceramic shell, the humidity in the drying area should be controlled at 30-40%, and the temperature at 22-26℃.

[0177] When drying the surface layer or the second layer of the ceramic shell, control the airflow speed in the drying area so that the temperature difference between the dry bulb and the wet bulb does not exceed 2℃.

[0178] Current technologies for drying ceramic shells generally require a drying environment with the highest possible temperature (since the ceramic shell to be dried is made by applying a slurry to a wax film, the drying temperature cannot exceed the melting temperature of the wax film) and the lowest possible humidity, in order to achieve the most efficient drying process. However, existing technologies have long suffered from a low yield rate of dried ceramic shells, mainly manifested in the surface layer of the ceramic shell (i.e., the layer in contact with the wax film) and the support layer near the surface, which is prone to cracking, also known as surface cracking. Ceramic shells with surface cracking are considered waste products, and since the dried ceramic shells cannot be rehydrated and reused, this results in a significant waste of time and materials.

[0179] Existing technologies lack effective solutions to this problem. Common methods to overcome surface cracking include: adding various reagents to the ceramic shell slurry; conducting pilot or small-scale tests on each batch of ceramic shells to adjust the drying temperature and time parameters for achieving the highest yield; and using vacuum rapid drying for the ceramic shells. However, existing technologies still have limitations:

[0180] 1. Adding various reagents to ceramic shell slurry will obviously increase material costs, and currently cannot effectively solve the problem of surface cracking.

[0181] 2. Adjusting the drying temperature and time parameters through pilot or small-scale tests can improve the yield rate to some extent, but on the one hand, it obviously slows down the drying efficiency, and on the other hand, the yield rate during large-scale drying is difficult to reach the yield rate of pilot or small-scale tests, and there is a relatively obvious instability.

[0182] 3. Vacuum rapid drying needs to be carried out in specific equipment. Although the drying efficiency of ceramic shells is high and the yield of dried products is high, it is limited by the size of the drying chamber of the equipment. In addition, there are costs for purchasing and using the equipment. When drying large-scale, large-size, low-value-added ceramic shells, there are certain cost increases or cost incompatibility issues.

[0183] After investigation, the applicant determined that the surface cracking phenomenon was mainly caused by technical reasons, such as defects in the application process and the ceramic shell slurry not meeting quality requirements.

[0184] 1. For ceramic shells with complex structures or significant thickness, drying in a high-temperature, low-humidity environment may result in the outer layer drying completely before the inner layer is fully dried. If the process is allowed to continue until both the inner and outer layers are completely dry, the outer layer may over-dry, easily leading to cracks. These external cracks are highly susceptible to propagation under stress, resulting in long cracks on the ceramic shell and rendering it unusable.

[0185] 2. The drying process of ceramic shells involves the evaporation of moisture from the ceramic shell slurry. This evaporation is endothermic, causing a drop in temperature of the wax film inside the ceramic shell. Wax is a material that expands and contracts with temperature changes. Therefore, during the drying process of the ceramic shell surface, the wax film gradually shrinks. Since the drying of the ceramic shell slurry generally follows an outside-inward trend, the interior of the surface ceramic shell will shrink along with the cooling wax film. As the moisture in the ceramic shell gradually evaporates, the wax film gradually warms up to the ambient temperature. At this point, the wax film expands due to heat and exerts a compressive force on the already contracted inner layer of the ceramic shell. Since the interior of the ceramic shell is often not yet completely dry and has not formed a solid shell layer, it is easily deformed and cracked by the compressive force of the wax film, resulting in surface cracks and rendering the product unusable.

[0186] Based on the applicant's research, the applicant changed the traditional technical practices of drying ceramic shells. When drying the surface layer, a high-humidity and relatively low-temperature drying environment was adopted, which allowed the surface ceramic shell to dry gradually in a very slow manner. In this way, the moisture in the ceramic shell would not evaporate rapidly during the drying process. This not only made the drying progress of the inside and outside of the ceramic shell more consistent, but also avoided the problem of the wax film cooling down due to the rapid evaporation of moisture in the ceramic shell. This effectively reduced the shrinkage and expansion of the wax film during the drying process of the ceramic shell, thereby significantly reducing the problem of surface cracking of the ceramic shell.

[0187] This invention gradually reduces the humidity and increases the temperature of the drying environment during the subsequent drying of the ceramic shell layer. This allows the drying efficiency to gradually increase as the ceramic shell gains a certain strength. Therefore, while ensuring good overall drying efficiency, it significantly improves the yield of batch-dried ceramic shells. Provided the ceramic shell slurry and slurry application operations meet the requirements, the yield of dried ceramic shells can generally reach over 95%.

[0188] Compared to traditional ceramic shell drying devices for casting, the ceramic shell drying device for casting of this invention, through good temperature control of the refrigerant and effective anti-icing control of the radiator, can ensure that the airflow entering the drying chamber has better flow stability and temperature stability. The humidity may fluctuate to some extent when washing the radiator, but since the ceramic shell drying method of this invention changes the traditional low humidity control requirements, it will not cause obvious problems in the drying of the ceramic shell. In fact, it can reduce the need for humidifier operation when drying the surface layer.

[0189] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A ceramic shell drying device for casting, characterized in that, It includes a drying chamber (11), a blower chamber (12), and an equipment compartment (13) that are isolated from each other; the drying chamber (11) has an air inlet on its side wall and filters the incoming air through a filter mechanism (6); a condenser dryer (1) is provided in the drying chamber (11) near the air inlet; a heater (2) is provided on the partition (4) between the drying chamber (11) and the blower chamber (12), and the airflow between the drying chamber (11) and the blower chamber (12) is connected through the heater (2); a blower (3) is installed on the side wall of the blower chamber (12) to blow out the gas in the blower chamber (12). The condenser dryer (1) includes: a compressor (101), a first tubular heat exchanger (102), an expansion valve (103), and a cold air radiator (104) arranged in a pipe configuration; the cold air radiator (104) is arranged along the cross-sectional direction of the main airflow direction inside the drying chamber (11); The outlet end of the compressor (101) is connected to the inlet end of the first tubular heat exchanger (102), the outlet end of the first tubular heat exchanger (102) is connected to the inlet end of the expansion valve (103), the outlet end of the expansion valve (103) is connected to the inlet end of the radiator (104), and the outlet end of the radiator (104) is connected to the inlet end of the compressor (101). The heat pipe inlet of the first tubular heat exchanger (102) is connected to the outlet of the compressor (101) through the first connecting pipe (1023), and the heat pipe outlet is connected to the inlet of the expansion valve (103) through the second connecting pipe (1024); the coolant inlet of the first tubular heat exchanger (102) is connected to an external liquid supply device through the third connecting pipe (1022), and the coolant outlet is connected to an external liquid storage device through the fourth connecting pipe (1021); a first booster pump (1025) is provided on the third connecting pipe (1022). The operation status of the condenser dryer (1), heater (2), and blower (3) is controlled by the control system. A first three-way valve (1026) is provided between the first booster pump (1025) and the first tubular heat exchanger (102); the inlet end of the first three-way valve (1026) is connected to the outlet end of the first booster pump (1025), one outlet end is connected to the fourth connecting pipe (1021), and the other outlet end is connected to the coolant inlet end of the first tubular heat exchanger (102); The first three-way valve (1026) is an electrically controlled three-way valve. The control signal receiving end of the first three-way valve (1026) is connected to the control system signal. An ambient temperature sensor is provided on the outside of the casting ceramic shell drying device. The ambient temperature sensor sends the ambient temperature of the casting ceramic shell drying device to the control system in real time. The control system controls the flow ratio between the two passages of the first three-way valve (1026) according to the temperature information sent by the received ambient temperature sensor.

2. The ceramic shell drying device for casting according to claim 1, characterized in that, The filtration mechanism (6) is a 250-400 mesh felt filter or a metal filter.

3. The ceramic shell drying device for casting according to claim 1, characterized in that, The external liquid supply device and the external liquid storage device are the first liquid storage tank (8), the third connecting pipe (1022) is connected to the bottom of the first liquid storage tank (8), and the fourth connecting pipe (1021) is connected to the top of the first liquid storage tank (8); the first liquid storage tank (8) is installed inside the equipment compartment (13) or outside the casting ceramic shell drying device.

4. The ceramic shell drying device for casting according to claim 1, characterized in that, The expansion valve (103) is equipped with a first electronic thermometer at its inlet. The control system receives the temperature information Y from the first electronic thermometer in real time and makes the following judgments: When Y∈U, the flow ratio between the two passages of the current first three-way valve (1026) is maintained; When Y∉U and Y is greater than Tmax, the first three-way valve (1026) is controlled to increase the flow rate to the first tubular heat exchanger (102); When Y∉U and Y is less than Tmin, the first three-way valve (1026) is controlled to reduce the flow rate to the first tubular heat exchanger (102); U is a preset temperature range, Tmax is the maximum value of U, and Tmin is the minimum value of U.

5. The ceramic shell drying device for casting according to claim 1, characterized in that, A second tubular heat exchanger (105) is provided between the first tubular heat exchanger (102) and the expansion valve (103). The second tubular heat exchanger (105) includes a heat dissipation pipe (1051), the inlet end of which is connected to the outlet end of the first tubular heat exchanger (102) through a fifth connecting pipe (1052), and the outlet end of the heat dissipation pipe (1051) is connected to the inlet end of the expansion valve (103) through a sixth connecting pipe (1053).

6. The ceramic shell drying apparatus for casting according to claim 5, characterized in that, The second tubular heat exchanger (105) further includes: a heat exchange tube array (1054), wherein the heat exchange tube array (1054) is arranged close to the heat dissipation tube array (1051); A second three-way valve (106) is provided between the compressor (101) and the first tubular heat exchanger (102). The inlet end of the second three-way valve (106) is connected to the outlet end of the compressor (101), one outlet end is connected to the inlet end of the first tubular heat exchanger (102), and the other outlet end is connected to the inlet end of the heat exchange tube (1054) through the seventh connecting pipe (1056). The outlet end of the heat exchange tube (1054) is connected to the inlet end of the first tubular heat exchanger (102) through the eighth connecting pipe (1055).

7. The ceramic shell drying apparatus for casting according to claim 6, characterized in that, The second three-way valve (106) is an electrically controlled three-way valve. The control signal receiving end of the second three-way valve (106) is connected to the control system signal. An ambient temperature sensor is provided outside the casting ceramic shell drying device. The ambient temperature sensor sends the ambient temperature outside the casting ceramic shell drying device to the control system in real time. The control system controls the flow ratio between the two passages of the second three-way valve (106) according to the temperature information sent by the received ambient temperature sensor.

8. The ceramic shell drying apparatus for casting according to claim 1, characterized in that, The partition (4) is provided with a cleaning system (5) at the position of the cold radiator (104). The cleaning system (5) includes: a spray plate (504) set on the top of the cold radiator (104) and covering the cold radiator (104), and a support drain plate (505) set at the bottom of the cold radiator (104). The spray plate (504) has several spray holes (506) on the side facing the cold radiator (104), and all of the spray holes (506) are connected to the water washing pipe (503); the water washing pipe (503) is connected to the liquid supply pipe (501) through the second booster pump (502), and the liquid supply pipe (501) is connected to the cleaning water storage mechanism; The supporting drain plate (505) has a liquid collection tank at the position of the cold radiator (104), and the bottom of the cold radiator (104) is fixed on the supporting drain plate (505) on both sides of the liquid collection tank; the bottom of the liquid collection tank is connected to the external water treatment mechanism through the drain pipe (507); The control signal input terminal of the second booster pump (502) is connected to the control system signal, and the control system controls the start of the second booster pump (502) according to the analysis results of the washing and cooling radiator analysis.

9. The ceramic shell drying apparatus for casting according to claim 8, characterized in that, The drying chamber (11) is equipped with a first anemometer (10) and a second anemometer (9) on both sides of the cold air duct (104) along the airflow direction. The analysis of the cold air radiator includes: velocity difference analysis, which includes: Step 1.1 Receive the first wind speed S1 from the first anemometer (10) and the second wind speed S2 from the second anemometer (9) in real time; Step 1.2 Calculate the wind speed difference C = S1 - S2; Step 1.3 When C≥K1, it is determined that the cold radiator needs to be washed, and the second booster pump (502) is started; K1 is a preset flow rate difference threshold.

10. The ceramic shell drying apparatus for casting according to claim 8, characterized in that, The outlet end of the radiator (104) is equipped with a second electronic thermometer, which is used to detect the temperature of the refrigerant at the end of the radiator (104) and send the detection result to the control system; The analysis of the radiator includes: radiator temperature analysis, which includes: Step 2.1 Receive temperature information T from the second electronic thermometer in real time; Step 2.2 When T≤K2, it is determined that the cold radiator needs to be cleaned, and the second booster pump (502) is started; K2 is a preset temperature threshold.

11. The ceramic shell drying apparatus for casting according to claim 8, characterized in that, The compressor (101) is equipped with an electronic barometer at its inlet end, which is used to detect the refrigerant pressure at the inlet end of the compressor (101) and send the detection result to the control system. The analysis of the radiator cooling system includes: refrigerant pressure analysis, which includes: Step 3.1 Receive pressure information P from the electronic barometer in real time; Step 3.2 When P≤K3, it is determined that the cold radiator needs to be cleaned, and the second booster pump (502) is started; K3 is a preset pressure threshold.

12. The ceramic shell drying apparatus for casting according to claim 8, characterized in that, The analysis of the radiator washing process includes: timing analysis, which includes: Step 4.1 Obtain the current time information N in real time; Step 4.2 When N∈M, it is determined that the cold air radiator needs to be washed, and the second booster pump (502) is started; M is a preset set of time points.

13. The ceramic shell drying apparatus for casting according to any one of claims 9-12, characterized in that, Several jet heads (7) are arranged along one side of the radiator (104); the jet head (7) is inclined downward towards the radiator (104); all the jet heads (7) are connected to the output end of the air compressor. At this time, the control system starts the second booster pump (502) for a first preset time and then shuts down the second booster pump (502), and starts the air compressor for a preset second time and then shuts down the air compressor.

14. A ceramic shell drying system for casting, characterized in that, The drying area is equipped with at least one casting ceramic shell drying device as described in any one of claims 1-13, at least one humidifier, several temperature sensors and humidity sensors located at different positions, and a drying control system that is connected to the casting ceramic shell drying device, humidifier, temperature sensors and humidity sensors. The drying control system receives temperature information from the temperature sensor and humidity information from the humidity sensor, and controls the temperature and humidity within the drying area according to preset settings for the humidifier and ceramic shell drying device.

15. The ceramic shell drying system for casting according to claim 14, characterized in that, The drying area is a drying room or the drying chamber of a drying device.

16. A method for drying ceramic shells, characterized in that, The ceramic shell to be dried is dried using the ceramic shell drying system for casting as described in any one of claims 14-15.

17. The method for drying ceramic shells according to claim 16, characterized in that, When drying the ceramic shell, perform the following steps: When drying the surface layer of the ceramic shell, control the humidity in the drying area to be 70-90% and the temperature to be 20-24℃. When drying the second layer of the ceramic shell, the humidity in the drying area should be controlled at 50-70%, and the temperature at 22-26℃. When drying the third layer of the ceramic shell, the humidity in the drying area should be controlled at 40-50% and the temperature at 22-26℃. When drying the fourth and subsequent layers of the ceramic shell, the humidity in the drying area should be controlled at 30-40%, and the temperature at 22-26℃.

18. The method for drying ceramic shells according to claim 17, characterized in that, When drying the surface layer or the second layer of the ceramic shell, control the airflow speed in the drying area so that the temperature difference between the dry bulb and the wet bulb does not exceed 2℃.

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