Shakeout testing device and using method thereof

Abstract

The invention discloses a device for testing the wear resistance of a coating in a normal temperature-high temperature environment and a use method of the device. Belongs to the technical field of coating performance testing and verification. The device comprises a shell, a tank body, a conveying mechanism, a shakeout mechanism, a flow meter, a microwave emitter, a temperature control unit, a circuit control cabinet and the like. A heating control unit is arranged in the device, the interior of the heating unit can be heated to a set temperature according to set parameters, heat preservation is conducted, meanwhile, sand grains are conveyed through an automatic conveying device, and the sand grains are conveyed to a funnel above and sequentially pass through a sand shakeout switch and a flow meter at the initial speed zero; microwaves emitted by the microwave emitter are reflected when encountering the metal base material and are transmitted to the flowmeter switch controller in an electric signal mode, the machine stops running, and coating abrasion resistance evaluation is completed. According to the device, the performance of the coating at different temperatures and different scouring angles can be evaluated, so that the result is closer to the actual working condition, and the detection efficiency, the experiment accuracy and the repeatability are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coating performance testing and verification, and in particular relates to a device for testing the wear resistance of a coating in a high temperature environment and a method for using the device. Background Art

[0002] With the development of coating technology, coating plays an important role in many aspects. For example, it can achieve energy saving and consumption reduction in power plants, boilers, and cookers, and it can achieve weather corrosion resistance, acid and alkali corrosion resistance in metal structure buildings. People have higher and higher requirements for the quality of coatings, and the wear resistance of coatings is directly related to the effect of coatings in practical applications. At present, the wear resistance of coatings is mainly evaluated through falling sand experiments, but there are still great deficiencies. On the one hand, the laboratory's falling sand test device is still in the traditional manual sanding or simple mechanical sanding stage. The former mainly relies on manual handling and pouring into the upper funnel, and then directly falling to impact the coating. This method is not only labor-intensive and inefficient, but also has poor experimental accuracy and repeatability. Different experimenters or equipment will have a great impact on the results. At the same time, a large amount of fine dust will be generated during the falling sand process, which will have an adverse effect on the health of the testers. The latter mainly relies on simple mechanical reciprocating motion to send sand to the top and dump it, so as to achieve repeated and uninterrupted use of sand inside the equipment, such as patent CN109975148 B. This method solves the time-consuming and laborious problem of manual experiments, but in terms of the statistics of the amount of sand in the experiment, it is difficult to accurately count the amount of sand in the process through traditional weighing and counting because it is repeatedly used. At the same time, due to the airtightness of the equipment, there is no way to confirm the damage time of the internal coating. There is a large deviation in the experimental data; secondly, the existing scouring test equipment can only test the scouring data at a fixed angle, which is very different from the multi-angle and multi-media turbulent impact in the actual equipment, making it difficult for laboratory data to match the actual situation on site. Finally, the existing equipment can only simulate the conventional wear resistance of the test coating at room temperature, but most coatings, especially functional coatings, are used in special environments such as high temperature, acid and alkali, and the difference in environment will make the coating performance very different. Therefore, the present invention designs an automatic sand scouring test device that can locally control the temperature and regulate the concentration of the environmental medium, and conducts the anti-scouring and wear performance test of the coating under different temperatures and environments. At the same time, the automatic sand loading and sand quantity statistics system greatly improves the detection efficiency of the anti-wear of the coating, saves labor costs and time costs, and improves the high accuracy and repeatability of the experiment. At the same time, in the design of this equipment, the safety and environmental protection issues during the experiment are fully considered, and a special exhaust gas treatment unit is set up. Summary of the invention

[0002] In order to overcome the shortcomings of existing testing devices, the present invention provides a device and a method for using the device to test the erosion and wear resistance of a coating under a specific environment. The device can be used to test the wear performance of the coating, simulate the service state of the coating under high temperature and specific medium environment, and improve the detection efficiency of the coating's wear resistance, saving labor costs and time costs, and ultimately improving the accuracy and repeatability of the experiment.

[0003] To achieve the above-mentioned objectives, the present application provides the following technical solutions: an automatic sand dropping device that can test the wear resistance of a coating under a high temperature environment, characterized in that the device includes a shell, a tank body, a sand conveying mechanism, a sand dropping mechanism, a sand dropping flowmeter, a small microwave transmitter, a heating and temperature control unit, a gas control unit, a circuit control cabinet, an exhaust gas treatment unit, etc.

[0004] The outer shell is equipped with vents, a sand falling flow meter display screen and a circuit control switch, and is connected to the sand falling mechanism and the test bench support frame. A support rod is set at the bottom of the test bench support frame to make the overall frame more solid. The tank is equipped with a sand conveying mechanism, a sand falling mechanism, a sand falling flow meter, an angle-adjustable sample workbench, a small microwave transmitter, and a heating and temperature control unit. The sand conveying mechanism includes a reduction motor, a transmission pulley, a transmission belt, an arc-shaped bucket, and a guide roller. The reduction motor is located at the bottom of the tank body. The output shaft of the reduction motor is connected to the transmission pulley. The transmission pulley makes the transmission belt run along the fixed running track of the guide roller. An arc-shaped bucket is installed on the transmission belt, and test sand is placed in the sand collecting container at the bottom of the device; the sand falling mechanism includes an upper funnel, a dropping pipe, a sand falling switch, a sand falling flowmeter, and a sand collecting container. The upper end of the dropping pipe is installed with an upper funnel, and the sand falling switch, the sand falling flowmeter, and the collecting container are installed downward in sequence. The sand is transmitted to the upper funnel of the sand falling mechanism by the conveyor belt, passes through the sand baffle and the annular reduction chamfer groove, starts to fall from an initial velocity of zero, passes through the sand falling switch and the sand falling flowmeter, hits the sample on the test bench support frame, and finally falls into the sand collecting container at the bottom of the mechanism. The heating and temperature control unit is a shell welded from high-temperature resistant stainless steel. The shell is inlaid with refractory bricks for insulation. The heating tube and temperature measuring thermocouple are fixed on the refractory bricks. The upper right corner of the shell is made of high-temperature resistant quartz glass, which is bonded to the shell by a high-temperature adhesive to facilitate the microwaves of the microwave transmitter to penetrate into the sample surface. The gas control unit provides the required specific gas for the entire system as required during the experiment, and tries to simulate the atmosphere environment in actual working conditions. It is mainly composed of gas storage tanks, gas pipes, flow controllers, atmosphere concentration meters, etc. The exhaust gas treatment unit mainly collects special gases that overflow during the experiment to avoid damage to personnel and the environment. It is mainly composed of gas pipes, one-way valves, and treatment liquid pools.

[0005] The sample work rack is placed inside the stainless steel shell, and a door is set on the side to facilitate the placement of samples. The sample work rack includes a test bench, a test bench support rod, and a sample fixing bolt. They are connected through a specific mechanism, and the force angle of the test bench can be adjusted during the experiment to achieve multi-angle flushing test evaluation. The test bench is located directly below the drop tube and is installed counterclockwise. One end of the test bench support rod fixes the test bench and the other end is connected to the sample work rack. The sample fixing bolt is used to fix the test object and adjust the position of the test object on the test bench; the small microwave transmitter is installed outside the shell approximately perpendicular to the test bench, and the microwave is projected onto the sample surface through the quartz glass skylight of the shell. The signal processor is located at the rear end of the microwave transmitter and is connected to the sand drop switch at the upper end of the drop tube through a wire.

[0006] The circuit control cabinet is located on the outside of the shell and is responsible for the control operation of the entire equipment, mainly including: 1. Control, measurement and display of internal heating temperature; 2. Control of the reduction motor; 3. Monitoring of the falling sand flow rate and operating time, and can display the total amount of sand flowing after the operation; 4. Monitoring of internal atmosphere concentration.

[0007] The invention is characterized in that a conical sand retaining plate is arranged on the upper end of the drop pipe.

[0008] The present invention is characterized in that the upper end of the drop tube passes through the bottom of the upper funnel and extends a certain length into the funnel, and an annular sand grain deceleration chamfer groove can be formed at the connection between the drop tube and the bottom of the upper funnel. The angles between the upper funnel and the drop tube wall are 45±1° and 65±1° respectively.

[0009] The invention is characterized in that one side of the conveyor belt is a plane, and the other side is made into an arc-shaped bucket. The arc-shaped bucket drives sand particles from the bottom to move toward the upper funnel on the top, and the sand particles in the arc-shaped bucket above the upper funnel will fall into the funnel.

[0010] The invention is characterized in that a material dropping switch and a sand falling flow meter are arranged in the material dropping pipe, the material dropping switch will be closed after receiving a signal, and no sand will fall downward, and at the same time, the sand falling flow meter will calculate the total amount of sand particles passing through the material dropping pipe.

[0011] The present invention is characterized in that the test bench is counterclockwise mounted just below the drop tube, and the test bench is welded to the sample work frame through a connecting rod, which increases the stability and can adjust the inclination angle of the sample platform according to actual needs to evaluate the anti-scouring ability of the product at different angles. The test bench is equipped with four sample fixing bolts for fixing the test object and adjusting the position of the test object on the test bench.

[0012] The present invention is characterized in that the small microwave transmitter in the housing is installed almost vertically to the test bench. Since microwaves will be reflected only when they encounter metal, the sample workbench, connecting rods, drop tubes, etc. are all made of non-metallic materials. The center of the microwave transmitter can emit microwaves, and the circular ring part extending outward from the center can receive reflected waves, which are converted into signals and transmitted to the drop sand flow meter switch at the upper end through wires.

[0013] The invention is characterized in that a vent is installed on one side above the shell.

[0014] The invention is characterized in that the conveyor belt moves in a fixed direction along the guide rollers under the driving of the conveyor belt wheel. There are four groups of guide rollers, which are respectively installed on the left and right sides of the upper end and the left and right sides of the lower end of the conveyor belt.

[0015] The present invention is characterized in that, in order to prevent the conveyor belt from falling off, a conveyor belt positioning groove is installed on the conveyor belt movement track.

[0016] The invention is characterized in that three fixed sleeves and fastening bolts are provided, and the sample working frame, the material dropping pipe and the falling sand flow meter device are fixed in the fixed sleeves on the supporting frame through the fastening bolts.

[0017] The present invention is characterized in that, by arranging a gas control unit and an exhaust gas treatment unit, laboratory simulation and evaluation of product performance test experiments under different atmosphere environments are realized.

[0018] The beneficial effects of the present application are as follows: the present application adopts a conveyor belt to realize the transmission of sand particles. After the sand particles are transported to the upper funnel, they pass through the sand retaining plate and the annular deceleration chamfered groove, and successively pass through the sand falling switch and the sand falling flowmeter. When the falling sand particles penetrate the coating, the emitted microwaves will be reflected when encountering the metal substrate, and the reflected signal will be transmitted to the sand falling flowmeter switch. The switch is closed, the machine stops running, and the amount of sand falling will be displayed on the external display. After the sand particles are put into the device, it can be turned on for automatic operation, which can greatly improve the detection efficiency of the coating wear resistance, save labor costs and time costs, and also improve the efficiency and accuracy of the test. And a vent is set so that the fine dust generated during the operation of the device can be discharged to eliminate the impact of dust on the human body. The sand retaining plate and the annular deceleration chamfered groove in the application can make the sand particles fall evenly, while ensuring that the initial velocity of the sand particles from the drop pipe downward is as zero as possible, further improving the accuracy of the test. A rough surface is made on one side of the conveyor belt, and an arc-shaped bucket is made on the other side, which is also to improve the transmission efficiency of the sand particles. Conveyor belt positioning grooves are also installed on both sides of the conveyor belt to prevent the conveyor belt from falling off. Guide rollers are also installed on the left and right sides of the upper end and the left and right sides of the lower end of the tank body to ensure that the conveyor belt runs stably in the correct direction. The microwave transmitter is installed almost vertically to the test bench. The emitted microwaves will be reflected back after encountering the metal substrate. After receiving the reflected signal, it is transmitted to the sand drop switch signal receiver at the upper end through a wire to realize automatic switch control. At the same time, the sand falling through the flowmeter can accurately display its flow rate. It can be seen that the automatic sand drop device provided by the present application can improve the detection efficiency of the wear resistance of the coating, save labor costs and time costs, and at the same time, it has a reliable structure, safe operation, and can improve the accuracy and efficiency of the test. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Figure 1 This is a front view of an automatic sand falling device of the present application. Figure 2 It is a side view of an automatic sand falling device of the present application. Figure 3 It is a schematic diagram of a funnel-shaped annular deceleration chamfer groove on an automatic sand falling device of the present application. Figure 4 It is a schematic diagram of a funnel-shaped conical sand retaining plate on an automatic sand falling device of the present application. Figure 5 It is a schematic diagram of an arc-shaped bucket and a bucket conveyor belt of an automatic sand falling device of the present application. Figure 6 It is a three-dimensional diagram of an arc-shaped bucket of an automatic sand falling device of the present application. Figure 7 It is a schematic diagram of a conveyor belt and a pulley of an automatic sand falling device of the present application. Figure 8 It is a schematic diagram of a conveyor belt guide groove of an automatic sand falling device of the present application. Fig. 9 This is a schematic diagram of the installation positions of a falling sand switch and a falling sand flow meter of an automatic falling sand device of the present application. Fig.10 It is a schematic diagram of the transmitting position and receiving panel of a microwave transmitter of an automatic sand falling device of the present application. Fig.11 It is a schematic diagram of an angle-adjustable stage of an automatic sand falling device of the present application. Fig.12 It is a bottom view of the bottom of a test bench of an automatic sand falling device of the present application. In the figure: 1-shell, 2-tank, 3-sand falling pipe upper funnel, 4-sand falling switch, 5-sand falling pipe, 6-sample workbench, 7-movable door, 8-guide roller, 9-reduction motor, 10-sand falling flowmeter workbench, 11-signal receiver, 12-wire, 13-display, 14-switch, 15-signal processor, 16-arc bucket, 17-experimental sand, 18-ventilation port, 19-fixed casing, 20-support frame, 21-reduction motor, 22-sand baffle, 23-sand falling flowmeter switch controller, 24-sand falling flowmeter signal receiver , 25-sand falling flowmeter, 26-microwave reflection signal processor, 27-microwave transmitter, 28-test bench, 29-sand outlet, 30-motor transmission rod, 31-guide groove, 32-sample fixing bolt, 33-test bench support rod, 34-angle control mechanism, 35-air pipe, 36-flow controller, 37-tank, 38 waste liquid recovery pool, 2202-annular deceleration chamfer groove, 2701-reflection microwave receiving panel, 2702-microwave transmitting hole, 3001-transmission belt drive wheel, 3002-bucket drive rack, 3003-transmission belt rack. DETAILED DESCRIPTION The following will be combined with the accompanying drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Figure 1-7 , an embodiment provided by the present application: 1. An automatic sand falling device, characterized in that it includes a shell 1, a tank 2, a sand conveying mechanism, a sand falling mechanism, a sand falling flowmeter 25, a small microwave transmitter 27, a sample working rack 6, and a circuit control cabinet 14. The outer shell is equipped with a vent 18, a falling sand flow meter display screen 13 and a circuit control switch 14, and is connected to the falling sand mechanism and the test bench support frame 20. A support rod 33 is arranged at the bottom of the test bench 28 to make the overall frame more solid. The sand conveying mechanism includes a reduction motor 9, a transmission pulley 3001, a bucket conveyor belt 3002, an arc-shaped bucket 16, and a guide roller 8. The reduction motor 21 is located at the bottom of the tank body. The output shaft 30 of the reduction motor is connected to the transmission pulley 3001. The gear of the transmission pulley 3001 can mesh with the bucket conveyor belt 3002 and the conveyor belt rack 3003, so that the bucket conveyor belt 3002 runs along the fixed running track of the guide roller 8. The arc-shaped bucket 16 is installed on the conveyor belt. The test sand 1 is placed in the sand collecting container at the bottom of the device. 7; The sand falling mechanism includes an upper funnel 3, a dropping pipe 5, a sand falling switch 4, a sand falling flowmeter 25, and a sand collecting container. The upper funnel 3 is installed on the upper end of the dropping pipe, and the sand falling switch 4, the sand falling flowmeter 25, and the collecting container are installed downward in sequence. The sand is transmitted to the upper funnel 3 of the sand falling mechanism by the conveyor belt, passes through the sand retaining plate 22 and the annular deceleration chamfer groove 2202, starts to fall from an initial velocity of zero, passes through the sand falling switch 4 and the sand falling flowmeter 25, hits the sample on the test bench support frame 6, and finally falls into the sand collecting container at the bottom of the mechanism. A door 7 is provided next to the sample workbench to facilitate the placement of samples and experimental sand. The sample workbench 6 comprises a test bench 28, a test bench support rod 33, a sample fixing bolt 32, a small microwave transmitter 27, and a signal processor 26. The test bench 28 is located directly below the drop tube 5 and is installed in a counterclockwise tilt. One end of the test bench support rod 33 fixes the test bench 28 and the other end is connected to the sample workbench 6. The sample fixing bolt 32 is used to fix the test object and adjust the position of the test object on the test bench; the small microwave transmitter 27 is approximately perpendicular to the test bench 28 and does not affect the normal falling of the test sand particles. The signal processor 26 is located at the rear end of the microwave transmitter 27 and is connected to the sand drop switch signal receiver 24 at the upper end of the drop tube through a wire 12. A conical sand baffle 2201 is arranged at the upper end of the drop pipe in this embodiment. In order to prevent the sand transported by the conveyor belt to the top of the drop pipe from falling directly into the pipe and causing test inaccuracy, a sand baffle device is designed so that the sand that may fall into the pipe is blocked by the sand baffle to change the direction of movement and flow to the annular deceleration chamfer groove 2202 on the side wall of the funnel, so that the initial falling velocity is as close to zero as possible. The upper end of the drop tube 5 in this embodiment passes through the bottom of the upper funnel 3 and extends a certain length into the funnel, and an annular sand grain deceleration chamfer groove 2202 can be formed at the connection between the drop tube 5 and the bottom of the upper funnel 3. The angles between the upper funnel 3 and the wall of the drop tube 5 are 45±1° and 65±1° respectively. The chamfer groove 2202 is filled with sand grains falling from the top of the conveyor belt, which has a friction deceleration effect on the subsequent sand grains. One side of the transmission belt in this embodiment is geared. Figure 5 The other side is formed into an arc-shaped bucket 1601, which drives the sand grains from the bottom to move toward the upper funnel 3 at the top, and the sand grains in the arc-shaped bucket above the upper funnel will fall into the funnel 3. In this embodiment, a material drop switch 4 and a sand drop flow meter 25 are provided in the material drop pipe 5. The material drop switch 4 will be closed after receiving a signal, and no sand will drop downward. At the same time, the sand drop flow meter 25 will calculate the total amount of sand particles passing through the material drop pipe. The test bench 28 in this embodiment is counterclockwise mounted just below the drop tube 5, and the test bench 28 is welded to the sample work rack 6 via a connecting rod 33 to increase stability. The test bench 28 can adjust the angle required for the experiment as required through the mechanism settings 3401 and 3402 thereon. Four sample fixing bolts 32 are installed on the test bench 28 to fix the test object and adjust the position of the test object on the test bench. The small microwave transmitter 27 installed in the sample work rack in this embodiment is installed almost vertically to the test bench 28. Since microwaves will be reflected only when they encounter metal, metal materials cannot be used in the sample work rack 6, including the test bench 28, the connecting rod 33, the drop tube 5, etc. The microwave transmitter center position 2702 can emit microwaves, and the circular ring part 2701 extending outward from the center can receive the reflected wave. The reflected wave is converted into an electrical signal in the signal converter 26 and transmitted to the signal receiver 24 at the upper end through the wire 12. The signal receiver controls the switch 23 of the falling sand flowmeter. In this embodiment, the atmosphere control unit has a gas pipeline 35, a gas storage tank 37, and a flow controller to transport specific gas into the equipment. Furthermore, according to actual needs, multiple gas sources can be configured to achieve simulation testing under mixed gas. In this embodiment, considering the safety of personnel and environmental protection during the process, an exhaust gas treatment device, an exhaust gas collection pool 38, is set up to treat the exhaust gas during the entire experimental process. A vent 18 is installed on one side above the shell of this embodiment to remove dust and eliminate the harm of fine fly ash to the human body. The sand conveyor belt 3002 of this embodiment moves in a fixed direction along the guide roller 8 under the drive of the conveyor belt wheel 3001. There are four groups of guide rollers, which are respectively installed on the left and right sides of the upper end and the left and right sides of the lower end of the conveyor belt. In this embodiment, in order to prevent the conveyor belt 3002 from falling off, a conveyor belt positioning groove 31 is installed on the conveyor belt movement track. In this embodiment, three fixed sleeves 19 and fastening bolts 19 are further provided, and the sample working frame 6, the material dropping pipe 5 and the falling sand flowmeter 25 are fixed in the fixed sleeves 19 on the support frame by the fastening bolts 19. The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application. It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An automatic sand falling device, characterized in that the device includes a shell, a tank, a sand conveying mechanism, a sand falling mechanism, a sand falling flow meter, a small microwave transmitter, a heating and temperature control unit, a gas control unit, a circuit control cabinet, an exhaust gas treatment unit, etc. The outer shell is equipped with vents, a falling sand flow meter display screen, an atmosphere concentration tester and a circuit control switch, and is connected to a falling sand mechanism and a test bench support frame. A support rod is arranged at the bottom of the test bench support frame to make the overall frame more solid. A sand conveying mechanism, a sand falling mechanism, a sand falling flowmeter, a sample workbench, a small microwave transmitter and a heating temperature control unit are arranged in the tank body. [0001] The sand conveying mechanism includes a reduction motor, a transmission pulley, a transmission belt, an arc-shaped bucket, and a guide roller. The reduction motor is located at the bottom of the tank body, and the output shaft of the reduction motor is connected to the transmission pulley. The transmission pulley enables the transmission belt to run along the fixed running track of the guide roller. An arc-shaped bucket is installed on the transmission belt, and test sand is placed in a sand collecting container at the bottom of the device; the sand falling mechanism includes an upper funnel, a dropping pipe, a sand falling switch, a sand falling flowmeter, and a sand collecting container. The upper end of the dropping pipe is installed with an upper funnel, and the sand falling switch, the sand falling flowmeter, and the collecting container are installed downward in sequence. The sand is transmitted to the upper funnel of the sand falling mechanism by the conveyor belt, passes through the sand baffle and the annular reduction chamfer groove, starts to fall from an initial velocity of zero, passes through the sand falling switch and the sand falling flowmeter, hits the sample of the test bench support frame, and finally falls into the sand collecting container at the bottom of the mechanism. The heating and temperature control unit is a shell welded from high-temperature resistant stainless steel. The shell is inlaid with refractory bricks for insulation. The heating tube and temperature measuring thermocouple are fixed on the refractory bricks. The upper right corner of the shell is made of high-temperature resistant quartz glass, which is bonded to the shell by a high-temperature adhesive to facilitate the microwaves of the microwave transmitter to penetrate into the sample surface. The gas control unit provides the required specific gas for the entire system as required during the experiment, and tries to simulate the atmosphere environment in actual working conditions. It is mainly composed of gas storage tanks, gas pipes, flow controllers, atmosphere concentration meters, etc. The exhaust gas treatment unit mainly collects special gases that overflow during the experiment to avoid damage to personnel and the environment. It is mainly composed of gas pipes, one-way valves, and treatment liquid pools. The sample work rack is placed inside the stainless steel shell, and a door is set on the side to facilitate the placement of samples. The sample work rack includes a test bench, a test bench support rod, and a sample fixing bolt. They are connected through a specific mechanism. The force angle of the test bench can be adjusted during the experiment to achieve multi-angle flushing test evaluation. The test bench is located directly below the drop tube and is installed counterclockwise. One end of the test bench support rod fixes the test bench and the other end is connected to the sample work rack. The sample fixing bolt is used to fix the test object and adjust the position of the test object on the test bench; the small microwave transmitter is installed outside the shell approximately perpendicular to the test bench, and the microwave is projected onto the sample surface through the quartz glass skylight of the shell. The signal processor is located at the rear end of the microwave transmitter and is connected to the sand drop switch at the upper end of the drop tube through a wire. The circuit control cabinet is located on the outside of the shell and is responsible for the control operation of the entire equipment, mainly including:

1. Control, measurement and display of internal heating temperature; 2. Control of the reduction motor; 3. Monitoring of falling sand flow and running time; 4. Internal atmosphere concentration monitoring.

2. The automatic sand falling device according to claim 1, characterized in that: A conical sand baffle is arranged on the upper end of the drop pipe.

3. The automatic sand falling device according to claim 1-2, characterized in that: The upper end of the drop tube passes through the bottom of the upper funnel and extends a certain length into the funnel, forming an annular sand deceleration chamfer groove at the connection between the drop tube and the bottom of the upper funnel. The angles between the upper funnel and the drop tube wall are 45±1° and 65±1° respectively.

4. The automatic sand falling device according to claim 1, characterized in that: One side of the conveyor belt is flat, and the other side is made into an arc-shaped bucket. The arc-shaped bucket drives the sand from the bottom to the upper funnel on the top, and the sand in the arc-shaped bucket above the upper funnel will fall into the funnel.

5. The automatic sand falling device according to claim 1, characterized in that: A drop switch and a sand falling flow meter are set in the drop pipe. The drop switch will be closed after receiving the signal, the equipment will stop running, and the sand will no longer fall downward. At the same time, the sand falling flow meter will calculate the total amount of sand passing through the drop pipe.

6. The automatic sand falling device according to claim 1, characterized in that: The test bench is installed counterclockwise just below the drop tube, and the test bench is welded to the sample workbench through a connecting rod. While increasing the stability, the inclination angle of the sample platform can be adjusted according to actual needs. The test bench is equipped with four sample fixing bolts for fixing the test object and adjusting the position of the test object on the test bench.

7. The automatic sand falling device according to claim 1, characterized in that: The heating and temperature control unit is a shell welded from high-temperature resistant stainless steel. The shell is surrounded by inlaid refractory bricks for insulation. The heating tube and temperature measuring thermocouple are fixed on the refractory bricks. The upper right corner of the shell is made of high-temperature resistant quartz glass, which is bonded to the shell with a high-temperature adhesive to facilitate the microwaves of the microwave transmitter to penetrate into the sample surface, thereby realizing the control and adjustment of the temperature inside the shell.

8. The automatic sand falling device according to claim 1, characterized in that: By setting up a gas control unit and an exhaust gas treatment unit, laboratory simulation and evaluation of product performance test experiments under different atmosphere environments can be achieved.

9. The automatic sand falling device according to claim 1, characterized in that: The small microwave transmitter is installed almost vertically to the test bench. Since microwaves will only be reflected when they encounter metal, non-metallic materials are used in the sample workbench, including the test bench (acrylic plate), connecting rods, and drop tubes (PVDF-polyvinylidene fluoride tubes). The center of the microwave transmitter can emit microwaves, and the circular ring part extending outward from the center can receive reflected waves, which are converted into signals and transmitted to the drop sand flow meter switch at the upper end.

10. The automatic sand falling device according to claim 1, characterized in that: A vent is installed on one side above the shell to facilitate sample placement and observation.

11. The automatic sand falling device according to claim 1, characterized in that: Driven by the conveyor belt pulley, the conveyor belt moves along the guide roller in a fixed direction. There are four sets of guide rollers, which are respectively installed on the left and right sides of the upper end and the left and right sides of the lower end of the conveyor belt.

12. The automatic sand falling device according to claim 1, characterized in that: To prevent the conveyor belt from falling off, a conveyor belt positioning groove is installed on the conveyor belt movement track.

13. The automatic sand falling device according to claim 1, characterized in that: Three fixed sleeves and fastening bolts are provided, and the sample working frame, the material dropping pipe and the falling sand flow meter device are fixed in the fixed sleeves on the supporting frame through the fastening bolts.

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