All-round high-frequency eddy current heating and drying filter plate

Abstract

The present invention relates to the field of filter press equipment, and in particular to an all-round high-frequency eddy current heating and drying filter plate. The filter cake is heated and dried by utilizing and improving the autonomous heating generated by electromagnetic eddy current, which is different from the passive heating method of hot water heat conduction for heating and drying, and is also different from the heating method of resistance wire that is currently popular. The electromagnetic coil is wrapped in the filter plate of the present invention, and both sides of the coil plus the plate frame of the sealing plate generate eddy currents to form a three-dimensional, all-round surrounding heating. There is basically no magnetic leakage, and the efficiency of converting electrical energy into thermal energy is greatly improved, and no electromagnetic wave pollution is generated to the environment. In addition, the present invention improves the use of multiple sets of electromagnetic coils, and through a mixed connection method and an external control circuit, its efficiency is further improved, and the stability performance is better. The present invention greatly improves the working efficiency and service life, and can automatically adjust the temperature of the filtered object, which will have a beneficial effect on the field of filter press equipment.

Description

Technical Field

[0001] The invention relates to the field of filter press equipment, in particular to an omnidirectional high-frequency eddy current heating and drying filter plate. Background Art

[0002] The filter press is a special filtering medium that applies a certain pressure to the object to make the liquid seep out. It is a mechanical device and is a commonly used solid-liquid separation equipment. It was used in chemical production in the early eighteenth century and is still widely used in chemical, pharmaceutical, metallurgical, food, dye, brewing and other industries. It is also very popular in the environmental protection industry, such as sewage treatment. Because sewage contains a lot of sludge and harmful substances, it can be better separated by the filter press. The performance of the filter plate, the main filter unit of the filter press, directly affects the effect of the filter press. The final product after the filter press is a relatively pure filtrate and a block of filter residue or filter cake. The dryness of the filter cake and the speed of drying are the embodiment of the performance of the filter press. The modern method of filtering the filter cake is to heat it with hot water or to heat it with a resistance wire. Although these methods are available, they have low thermal effect, slow speed, high consumption and high cost. The applicant applied for "High-Pressure Double Diaphragm Filter Plate" on January 3, 2020. The patent specification with application number: 2020100066837 mentioned the use of high-frequency magnetothermal elements to heat the filter cake, which is equivalent to the high-frequency eddy current heating method described in this patent. However, there is a high-pressure water cavity between the heating plate and the keel of the eddy current support plate, and the space of the high-pressure water cavity increases with the increase of pressure, resulting in a greater distance between the two, and the magnetoelectric effect is not ideal.

[0003] The filter plate is a key component of the filter press performance. How to design the filter plate to heat and dry the filter cake more efficiently and have a simpler structure is a common goal pursued by the industry. Summary of the invention

[0004] Based on this, it is necessary to provide an all-round high-frequency eddy current heating and drying filter plate, which can accumulate heat energy more efficiently and quickly when applied to a filter press. The present invention utilizes and improves the heat energy of autonomous heating (hereinafter referred to as electromagnetic heating) generated by electromagnetic eddy current to heat and dry the filter cake, which is different from the current passive heating method of heat conduction through hot water for heating and drying, and is also different from the heating method of heating by resistance wire that is currently popular. The heating method of resistance wire is that the current emits heat through the resistor, the heating process is slow, and the power loss is large. The actual measured data of the two methods of filter plate heating under the same environment, the same voltage and the same power are obtained. The electromagnetic heating efficiency is 95-98%, while the resistance wire is 20-40%, and the temperature rise is also very different. For example, taking the temperature rise to 100 degrees as the standard, the former only takes 5 to 8 seconds, while the latter takes 40 to 50 seconds. In addition, from the perspective of service life, the electromagnetic heating plate can be used for more than 5 years, while the resistance wire heating plate, because the mains voltage may not be very stable and the sudden change of cold and heat has a greater impact on the resistance wire, its average service life is about 1 month, and sometimes it may even be burned out just after it is installed. The difference between the two is very obvious. The difference between the heating method in the present invention and the existing electromagnetic cooker is that although both of them are based on the principle of generating eddy current heating, the electromagnetic cooker only uses the eddy current generated by one side of the electromagnetic coil, and the magnetic leakage is large, which not only causes large power loss, but also has adverse effects on the environment, and human beings are affected by close operation. The present patent is a full-range high-frequency eddy current heating and drying filter plate, and its electromagnetic coil is wrapped in the filter plate of the present invention. Both sides of the coil plus the frame of the sealing plate generate eddy currents, forming a three-dimensional, full-range surrounding heating for the filter pressing object, and there is basically no magnetic leakage phenomenon. The efficiency of converting electrical energy into thermal energy is almost the limit, and no electromagnetic wave pollution is generated to the environment. In addition, the present invention improves the use of multiple electromagnetic coil units, and adds an external control circuit through a mixed connection method, so that its efficiency is further improved and the stability performance is better. The present invention greatly improves the working efficiency and service life, and can automatically adjust the temperature of the filtered object to prevent its temperature from being too high and causing adverse consequences.

[0005] The electromagnetic coil here is also called an excitation coil in the electromagnetic heating effect.

[0006] The all-round high-frequency eddy current heating drying filter plate includes a functional plate, a feed port and a filtrate port. The functional plate includes an electromagnetic coil plate, a water guide plate, a self-heating water filter plate and a sealing plate. The water guide plate, the self-heating water filter plate and the sealing plate are stacked and fixed together with the electromagnetic coil plate on both sides symmetrically from near to far. The periphery is a closed annular sealing connection. The sealing method can use convex ribs and grooves or flexible soft rubber sealing gaskets. It is equivalent to seven functional plates stacked together, and arranged relative to each other with the electromagnetic coil plate as the symmetrical surface, three plates are arranged on each side, and the functions of each functional plate on the two sides are also symmetrical.

[0007] The electromagnetic coil plate is provided with an annular groove whose size gradually increases from the inside to the outside and an excitation coil arranged therein. There are interconnecting openings between the grooves for routing the excitation coil. The electromagnetic coil plate substrate is a high-temperature resistant insulating composite material, such as: epoxy resin board, PPS engineering plastic, heat-resistant rubber board, mica board, high-temperature resistant silicone board, etc. The wire ends at both ends of the excitation coil are connected and fixed to the edge terminals of the board for connection to an external circuit.

[0008] The self-heating water filter plate is a metal material covered with micropores for filtering. The filtrate can pass through the micropores, and the filter residue is blocked. The excitation coil here is combined with the metal self-heating water filter plate. When the excitation coil is connected to high-frequency alternating current, the thickness of the water guide plate is appropriate, and a strong eddy current will be generated inside the metal self-heating water filter plate. When the eddy current is generated, the metal self-heating water filter plate will quickly generate heat energy, so that the filter cake formed by the filter residue closely together is quickly heated. Another function of the self-heating water filter plate is that the filtrate can be directly discharged from its micropores after vaporization during the heating of the filter cake.

[0009] The electromagnetic coil plate generates magnetic fields on both sides, so that the self-heating water filter plates on both sides

[0010] The electromagnetic coil, i.e. the magnetic field line of the excitation coil, is a closed ring and works in both directions, which can generate eddy current and heat energy on both sides of the self-heating filter plates.

[0011] The water guide plate is made of high temperature resistant insulating composite material, such as epoxy resin plate, PPS engineering plastic, heat resistant rubber plate, high temperature resistant silica gel plate, etc., and has a plurality of water guide grooves interconnected with each other and connected to the filtrate port on its surface, and the heated or vaporized filtrate can flow into the filtrate port through the water guide grooves. The advantage of the water guide plate is that it is suitable for the excitation coil to produce a magnetothermal effect on the self-heating water filter plate, and the water guide grooves inside it can provide a buffer space for the vaporized filtrate, and at the same time can adjust the temperature of the electromagnetic coil plate to prevent it from being burned due to excessive temperature and prevent the filtration object, such as or combustible filter residue, from having an excessively high temperature and causing adverse consequences.

[0012] A preferred example is an electromagnetic coil plate. Due to its large spatial area, a number of excitation coil units with the same winding direction can be distributed inside the plate. The excitation coil units are designed to be independent units that are easy to plug and unplug (or are fixed by snap-on or screws) and are compatible with and can be installed in the preset slots of the electromagnetic coil plate. The two ends of each excitation coil unit can be connected in series, in parallel, or a mixture of the two.

[0013] In the example, the thickness of the water guide plate is in the range of 10mm-20mm. The main function is to keep a more appropriate distance between the electromagnetic coil plate and the self-heating water filter plate to better exert the magnetoelectric effect. Therefore, the thickness of the water guide plate is controlled within this numerical range. In actual use, it is generally designed to be 15mm.

[0014] The external circuit connected to the excitation coil includes a high-frequency power conversion device and a corresponding control circuit. The high-frequency alternating current frequency output by the high-frequency power conversion device is 10-40kHz. The high-frequency power conversion device here is composed of a bridge rectifier and a voltage resonant converter.

[0015] In the example, the middle area of ​​the sealing plate is an empty frame structure, which is formed by sandwiching a thick layer of ferrous metal material between two thin layers of high-temperature resistant sealing materials and fixing them together. The high-temperature resistant sealing material here can also be coated on the surface of the ferrous metal material. The middle area is a filter residue accumulation, heating and drying area. The function of the high-temperature resistant sealing material is to prevent the filter cake from leaking water and form a space to accommodate the filter cake formed by the filter residue. Under the working state, the frame of the ferrous metal material can generate eddy current, which can heat and dry the filter cake all around, and cooperate with the two adjacent self-heating water filter plates to form a closed cavity, so as to achieve all-round heating and drying of the filter cake. The steam formed by heating can enter the water guide groove on the water guide plate from the micropores on the self-heating water filter plate.

[0016] The annular groove of the electromagnetic coil plate is circular, square or spiral, and there are intercommunication openings between the grooves. According to the shape of the electromagnetic coil plate and the layout position of the feed port.

[0017] The material of the self-heating water filter plate is metallic iron or an iron-containing alloy. The iron-containing material has good magnetic conductivity and is more likely to generate eddy currents.

[0018] The self-heating water filter plate is made of stainless steel, which has the same properties as iron, but has a higher hardness than iron, is not easily deformed, does not rust, and is durable.

[0019] A temperature sensor and a humidity sensor connected to the external control circuit are arranged inside or near the self-heating water filter plate, so that the temperature of the heated filter cake can be controlled at any time. When a certain temperature is reached, the control circuit maintains a constant temperature, and the humidity sensor detects the dryness and wetness of the filter cake. When the required index is reached, heating is stopped, thereby saving energy and improving efficiency.

[0020] The self-heating water filter plate can be designed to be a convex deformation plate away from the electromagnetic coil plate, that is, a bulging deformation in the direction of the central empty space of the sealing plate. The benefit of this is that this deformation increases the heating area of ​​the filter cake, especially increases the heating and drying force and the emission of hot steam in the middle of the filter cake. In addition, the number of micro-filter holes is increased, so that the steam generated by the heated filter cake can be separated more quickly. There are many shapes of convex deformation, such as spherical crown shape, but its apex does not protrude from the spatial range of the sealing plate and does not conflict with the self-heating water filter plate of another identical filter unit. In order to make the filter cake easier to fall after heating and drying, the sealing plate does not need to be fixedly connected to other functional plates at this time, as long as the peripheral docking surface can be sealed under external force. Here, each filter unit can also save one side of the sealing plate while ensuring that the thickness of the sealing plate is sufficient.

[0021] The feed inlet can be arranged at the center, the upper end, the middle of the two ends or any one of the four corners of the filter plate. The feed inlet can be arranged at different positions according to the object to be filtered and the disposal method.

[0022] The all-round high-frequency eddy current heating and drying filter plate is used as a filtering unit. Multiple repeated identical units are arranged on one axis or two axes to form the main body of the filter press. A filter cake is formed between two adjacent filtering units. Therefore, one unit only needs to provide one self-heating water filter plate to heat both sides of a filter cake. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is a schematic diagram of the overall appearance of one embodiment of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention;

[0025] Figure 2 for Figure 1 Exploded schematic diagram of the appearance;

[0026] Figure 3 This is a transparent schematic diagram of the front side of the electromagnetic coil plate, one of the embodiments of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention;

[0027] Figure 4 This is a front view of a water guide plate in one embodiment of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention;

[0028] Figure 5This is a front view schematic diagram of a self-heating water filter plate, which is one of the embodiments of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention;

[0029] Figure 6 This is a front view of a sealing plate in one embodiment of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention;

[0030] Figure 7 This is a schematic diagram of the position of the filtrate outlet at the center of the filter plate of the present invention in one embodiment of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention;

[0031] Figure 8 This is a schematic diagram of one embodiment of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention, in which the filtrate port is located in the middle of the two ends of the filter plate of the present invention;

[0032] Fig. 9 This is a schematic diagram of the position of the filtrate outlet at the upper end of the filter plate of the present invention, one embodiment of the omnidirectional high-frequency eddy current heating and drying filter plate of the present invention.

[0033] Marked in the figure: the omnidirectional high-frequency eddy current heating and drying filter plate body 10 of the present invention, the electromagnetic coil plate 11, the groove 12, the terminal 13, the water guide plate 21, the water guide groove 22, the self-heating water filter plate 31, the sealing plate 41, the feed inlet 51, the filtrate inlet 52, and the feed inlet 53. DETAILED DESCRIPTION

[0034] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0035] like Figures 1 to 6 As shown, one embodiment of the omnidirectional high-frequency eddy current heating drying filter plate

[0036] The body 10, the feed port 51 and the filtrate port 52, the electromagnetic coil plate 11, the water guide plate 21, the self-heating water filter plate 31 and the sealing plate 41, wherein the electromagnetic coil plate 11 is the center, and the two sides are symmetrically stacked from near to far and fixed together with the water guide plate 21, the self-heating water filter plate 31 and the sealing plate 41, and the periphery thereof is a closed annular sealing connection, and the sealing method can use convex ribs and grooves or a flexible soft rubber sealing gasket. The functional plates can be fixed by screws, bolts, buckles, etc. Figure 2 for Figure 1 The exploded diagram of the appearance shows the stacking relationship between the functional boards.

[0037] The electromagnetic coil plate 11 includes a plate frame, and an annular groove 12 with a size gradually increasing from the inside to the outside and an excitation coil arranged therein are provided inside the plate frame. There are interconnections between the grooves 12 for excitation coil wiring. The base plate of the electromagnetic coil plate 11 is a high temperature resistant insulating composite material. The purpose of using this material is: insulation to prevent the excitation coil from breaking and leaking, high temperature resistance to prevent deformation or melting due to excessive temperature, and the wire ends at both ends of the excitation coil are connected to the terminals 13 fixed on the plate frame for connection to the external circuit. The terminal 13 can be a socket or a terminal. Figure 3 It can be clearly seen in.

[0038] The self-heating water filter plate 31 is a metal material covered with micropores for filtering. Figure 4 No micropores can be seen, but there are micropores in the example.

[0039] In the example, the electromagnetic coil plate 11 generates a magnetic field on both sides, so that the heat conduction

[0040] The water filter plate 31 generates eddy current to heat and dry the filter residue or filter cake.

[0041] The water guide plate 21 is made of a high temperature resistant insulating composite material, and has a plurality of water guide grooves 22 interconnected with each other on its surface and connected to the filtrate port 52 . The heated or vaporized filtrate can flow into the filtrate port 52 through the water guide grooves 22 .

[0042] In the example, the electromagnetic coil plate 11, due to its large area, can be provided with a number of excitation coil units with the same winding direction. The excitation coil units are designed to be independent units that are easy to plug and unplug (or are fixed by snap-on or screws) and are compatible with the preset notches of the electromagnetic coil plate 11. The two ends of each excitation coil unit can be connected in series, in parallel, or in a mixture of the two. (Since there are many ways, they are not shown in the figure.) The advantage of doing this is that it can reduce the resistance of the entire electromagnetic coil plate 11 winding. At the same time, when a fault occurs, only the individual burnt excitation coil units are replaced, saving costs. And when several units in one series connection fail, they can continue to work, thereby improving efficiency.

[0043] The thickness of the water guide plate 21 is in the range of 10 mm to 20 mm.

[0044] The external circuit connected to the excitation coil includes a high-frequency power conversion device and a corresponding control circuit.

[0045] The high-frequency alternating current frequency output by the high-frequency power conversion device is 10-40kHz.

[0046] The sealing plate 41 is a hollow frame structure, the middle area is empty, and the periphery is made of a ferrous metal material and a layer of high-temperature resistant sealing material. During use, the middle area is a filter residue accumulation, heating and drying area.

[0047] The annular groove of the electromagnetic coil plate 11 is circular, square or spiral.

[0048] In a preferred embodiment, the material of the self-heating water filter plate 21 is metal iron.

[0049] In a preferred embodiment, the self-heating water filter plate 21 is made of stainless steel.

[0050] In the example, a temperature sensor and a humidity sensor connected to the external control circuit are provided in the self-heating water filter plate 21 (not shown in the figure).

[0051] In the example, the self-heating water filter plate 21 can be designed to be convex and deformed away from the electromagnetic coil plate.

[0052] Plate. It can be in the shape of a spherical cap, an ellipsoidal cap, a cylinder, a square column, etc. (not shown in the figure).

[0053] The feed inlet 51 can be located at the center of the filter plate. Figure 7 , see at the top Fig. 9 , see in the middle of both ends Figure 8 At or any of the four corners Figure 1 .

[0054] The general working process is: the filter pressing object enters the inlet 53 of the filter unit of the all-round high-frequency eddy current heating and drying filter plate body 10 of the present invention from the external pipe to the feed port 51 to the side of the self-heating water filter plate 31 away from the electromagnetic coil plate 11. In the middle area of ​​the sealing plate 41, the sealing plate at this time is butt-sealed with the sealing plate of another identical filter unit to form a sealed cavity. With the continuous increase of the external filter pressing object, the filter residue is continuously accumulated in the sealed cavity, and the filtrate formed by the microporous filtration on the self-heating water filter plate 31 enters the filtrate port 52. There are 4 filtrate ports, which can accommodate a large amount of water, a part of which flows into the water guide groove 22 on the surface of the water guide plate 21. As the amount of filtration increases, the filter residue accumulates continuously. When the filter press object with a large external pressure enters, the filter residue gradually forms a filter cake. At this time, the filter cake still contains a large amount of liquid or water. Under the action of the control system, the valve of the external input filter press object is closed, and the power is turned on. The current flows from the terminal 13 on the electromagnetic coil plate 11 to the excitation coil in the groove 12, so that the cavity formed by the adjacent filter units includes two self-heating water filter plates 31 and two sealing plates 41. The four-sided frame forms an eddy current and generates a large amount of heat to quickly heat and filter the filter cake therein. The steam formed by heating can enter the water guide groove 22 on the water guide plate from the micropores on the self-heating water filter plate 31. As the energy continues to increase and the temperature rises, the filtrate in the water guide plate 21 is also vaporized into steam to take away the heat, thereby automatically adjusting the overall temperature. At the same time, the temperature sensor and humidity sensor provided in the self-heating water filter plate 31 through the external control circuit take effect. When a certain temperature is reached, the control circuit maintains a constant temperature. The humidity sensor detects the dryness and humidity of the filter cake. When the required index is reached, the heating is stopped.

[0055] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An all-round high-frequency eddy current heating and drying filter plate, comprising a functional plate, a feed port and a filtrate port, characterized in that: The functional plate comprises an electromagnetic coil plate, a water guide plate, a self-heating water filter plate and a sealing plate, wherein the water guide plate, the self-heating water filter plate and the sealing plate are stacked in sequence from near to far with the electromagnetic coil plate as the center and fixed together with the electromagnetic coil plate, and the periphery thereof is a closed annular sealing connection, and the sealing method can be a convex rib and a groove or a flexible soft rubber sealing gasket; The electromagnetic coil plate is provided with an annular groove whose size gradually increases from the inside to the outside and an excitation coil arranged therein, and there are interconnecting openings between the grooves for the excitation coil wiring. The substrate of the electromagnetic coil plate is a high temperature resistant insulating composite material, and the wire ends at both ends of the excitation coil are connected and fixed to the edge terminals of the plate; The self-heating water filter plate is a metal material covered with micropores for filtering, through which the filtrate can pass and the filter residue is blocked; The electromagnetic coil plate generates a magnetic field on both sides, so that the self-heating water filter plates arranged on both sides thereof generate eddy currents to heat and dry the filter residue; the annular groove of the electromagnetic coil plate is spiral, circular or square, and when the annular groove is circular or square, there are interconnecting openings for wiring between the grooves; The water guide plate is made of a high temperature resistant insulating composite material, and a plurality of water guide grooves are provided on its surface which are interconnected and communicate with the filtrate port, and the heated or vaporized filtrate can flow into the filtrate port through the water guide grooves; The sealing plate is a hollow frame structure, which is a frame with an empty middle area formed by two layers of high temperature resistant sealing materials sandwiched between a layer of ferrous metal material, which are stacked and fixed together.

2. The omnidirectional high-frequency eddy current heating and drying filter plate according to claim 1, characterized in that: The electromagnetic coil plate may be provided with a plurality of excitation coil units having the same winding direction. The excitation coil units are designed to be independent units that are easily replaced and are adapted to the preset notches of the electromagnetic coil plate. Both ends of each excitation coil unit may be connected in series, in parallel, or a mixture of the two.

3. An all-round high-frequency eddy current heating and drying filter plate as claimed in claim 1 or 2, characterized in that: The external circuit connected to the excitation coil includes a high-frequency power conversion device and a corresponding control circuit.

4. The omnidirectional high-frequency eddy current heating and drying filter plate according to claim 1 or 2, characterized in that: The high-frequency alternating current frequency output by the high-frequency power conversion device in the electromagnetic coil plate is 10-40kHz.

5. The omnidirectional high-frequency eddy current heating and drying filter plate according to claim 1, characterized in that: The thickness of the water guide plate is in the range of 10 mm to 20 mm so as to enable the excitation coil to produce a magnetothermal effect on the self-heating water filter plate.

6. The omnidirectional high-frequency eddy current heating and drying filter plate according to claim 1, characterized in that: The middle area is a filter residue accumulation, heating and drying area, which prevents the filter cake from leaking water and forms a space to accommodate the filter cake formed by the filter residue. In the working state, the ferrous metal material frame can generate eddy current to heat and dry the filter cake all around, and cooperate with two adjacent self-heating water filter plates to form a closed cavity, so as to achieve all-round heating and drying of the filter cake. The steam formed by heating can enter the water guide groove on the water guide plate from the micropores on the self-heating water filter plate.

7. The omnidirectional high-frequency eddy current heating and drying filter plate according to claim 1, characterized in that: The self-heating water filter plate is made of metal iron or stainless steel, and is provided with a temperature sensor and a humidity sensor connected to an external control circuit.

8. The omnidirectional high-frequency eddy current heating and drying filter plate according to claim 7, characterized in that: The self-heating water filter plate can be designed as a deformed plate that protrudes away from the electromagnetic coil plate.

9. The all-round high-frequency eddy current heating and drying filter plate according to claim 1, characterized in that: The feed inlet may be arranged at the center, the upper end, the middle of the two ends or any one of the four corners of the self-heating water filter plate.

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