Filter for purifying high-purity vanillin

Abstract

The invention belongs to the field of vanillin filtering and processing, and discloses a filter for purifying high-purity vanillin, which comprises a shell and a heat preservation sleeve part distributed around the outer part of the shell, and further comprises a filtering assembly elastically arranged in the shell in a sliding manner, and a filter pressing plate is connected with a driver at the top end of the shell through a driving shaft; the filter pressing plate reciprocates in the shell, a solution is sucked into the position between the filter pressing plate and the filter assembly by changing the internal pressure of the shell below the filter pressing plate, or the solution penetrates through the filter assembly to be discharged, meanwhile, the filter plate drives the filter assembly to move through the connecting mechanism in the moving process, and the filter assembly is prevented from being blocked by impurities in the reciprocating motion process. According to the filter for purifying the high-purity vanillin, the reciprocating filter pressing plate is creatively adopted as a fluid conveying functional part, so that the economic investment of equipment is saved, the coordination of filter pressing and conveying in the filtering process is ensured, and the overall service life of the filter is ensured while the filtering efficiency of a vanillin solution is improved.

Description

Technical Field

[0001] This invention relates to the field of vanillin processing and filtration technology, specifically to a filter for high-purity vanillin purification. Background Technology

[0002] Vanillin, as a flavoring agent, is widely used in food processing. As a high-end flavoring agent, its processing requirements are also higher. Purification typically involves dissolving it in a fluid and filtering the fluid to prevent impurities in the fluid from affecting subsequent vanillin formation and to avoid direct discharge of the treated liquid, thus achieving water pollution prevention and purification. Common filtration equipment includes flow filtration or pressure filtration. For example, Chinese Patent CN101524603B discloses a fluid filter device in which a flow attachment provides a unique interface between the filter element and the filter tip. The fluid filter described herein typically provides a confined and sealed flow structure. The flow attachment is configured to deliver fluid into and out of the fluid filter, and to confine the fluid flowing into and out of the fluid filter within a separation structure of the flow attachment. The flow attachment also includes a sealing structure configured to adequately prevent leakage or at least limit leakage to a localized area away from the edge of the housing.

[0003] For example, Chinese patent CN218871423U discloses a filter press with dual filtration function, including a filter press body. Inside the filter press body is a first fixed plate. A support rod is fixedly connected below the first fixed plate, and a second fixed plate is fixedly connected below the support rod. A first filter screen is fixedly connected between the second fixed plate and the first fixed plate. A third fixed plate is provided inside the first fixed plate, and a second filter screen is fixedly connected below the third fixed plate. The material undergoes primary filtration through the second filter screen, and secondary filtration through the first filter screen. This improves the service life of the filter screen, increases filtration efficiency, and avoids filter screen damage. It solves the problem that existing filter presses using a single layer of filter media inevitably suffer filter cloth damage and perforation during use, leading to material leakage accidents, affecting the yield of solid products or the quality of liquid products, and frequently causing filter screen clogging.

[0004] However, existing filters still have certain shortcomings. In conventional filtration methods, such as flow filtration, insufficient pressure can lead to low filtration efficiency. If pressure is applied to increase filtration efficiency, pressure needs to be increased at the pump end, which severely tests the overall airtightness of the filter. If an additional pressure mechanism is designed into the filter to reduce the filtration space and avoid the filter being completely sealed, then the entire filtration system requires good coordination between the pressure mechanism and the pumping mechanism, resulting in a relatively high failure rate and higher cost. Summary of the Invention

[0005] The purpose of this invention is to provide a filter for high-purity vanillin purification, in order to solve the problem mentioned in the background art that the conventional filtration method, namely flow filtration, leads to insufficient pressure and low filtration effect. If pressure is applied to increase the filtration effect, pressure needs to be increased at the pump end, which puts great pressure on the overall airtightness of the filter. If an additional pressure mechanism is designed in the filter to reduce the filtration space and thus avoid the filter being completely sealed, then the entire filtration system needs good coordination between the pressure mechanism and the pumping mechanism, resulting in a relatively high failure rate and higher cost.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A filter for high-purity vanillin purification includes a housing and an insulating kit surrounding the housing, a filter assembly that is elastically slidably disposed inside the housing, and a filter press plate located above the filter assembly. The filter press plate is connected to a driver at the top of the housing via a drive shaft. The filter press plate reciprocates within the housing, drawing in solution between the filter press plate and the filter assembly by changing the internal pressure of the housing below the filter press plate, or allowing the solution to pass through the filter assembly and be discharged. Simultaneously, the filter plate moves the filter assembly via a connecting mechanism during its movement, preventing impurities from clogging the filter assembly during its reciprocating movement.

[0008] As a further step, the filter assembly includes an intermediate body with filter elements, and an outer ring for rotatably mounting the intermediate body and elastically sliding it within the housing, the lower end face of the intermediate body being connected to a rotating mechanism.

[0009] As a further step, the rotating mechanism is used to drive the intermediate body to rotate in the outer ring when the intermediate body moves vertically, and the rotation combined with the movement of the intermediate body itself produces the filter residue cleaning effect.

[0010] As a further step, the rotating mechanism includes a vertical cylinder fixedly mounted on the lower end face of the intermediate body, and a twisted rod threadedly connected to the vertical cylinder, wherein the twisted rod is fixedly mounted in the outer casing.

[0011] As a further step, the connecting mechanism includes an elastic body with its two ends connected to the filter press plate and the filter assembly, respectively, wherein the movement of the filter press plate drives the filter assembly to move synchronously before and after the elastic body is subjected to extreme stretching or compression.

[0012] As a further step, the connecting mechanism includes a vertically sliding rod installed in the outer ring, the top of the rod being connected to the filter plate, and the lower half of the rod being equipped with a first horizontal bar and a second horizontal bar distributed vertically, with a gap between the first horizontal bar and the filter assembly in the initial state.

[0013] Furthermore, the first horizontal bar follows the vertical bar and is angularly distributed about the axis of the filter assembly, while the first horizontal bar is located below the intermediate filter screen.

[0014] Furthermore, the blowholes on the surface of the first crossbar are connected to the flow supply mechanism through the hollow structure of the crossbar.

[0015] As a further step, the flow supply mechanism generates a fluid delivery effect by moving the filter plate, and the blowhole is used to blow fluid in from below the filter screen to backwash the filter screen.

[0016] As a further step, the suction holes on the surface of the second crossbar are connected to the supply mechanism through the hollow structure inside the crossbar, and are used by the supply mechanism to absorb the filtered solution.

[0017] Furthermore, the hollow structures inside the first and second crossbars are respectively connected to two unidirectional cavity structures inside the vertical bar, and the internal space of the vertical bar is separated by a partition plate to form two unidirectional cavities, both of which are connected to the flow supply mechanism.

[0018] As a further step, the flow supply mechanism includes an internal space of a filter press plate and a cover plate that elastically covers the top opening of the space, with the upper end face of the cover plate being fixedly connected to the tail end of a trigger rod.

[0019] Furthermore, the internal cavity of the vertical rod is connected to the internal space of the filter press plate.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] This high-purity vanillin purification filter innovatively employs a reciprocating filter press plate as the fluid transport component. This saves on equipment investment and ensures the coordination of filtration and transport during the filtration process. It improves the filtration efficiency of the vanillin solution while guaranteeing the overall lifespan of the filter. More importantly, this efficient filtration method not only reduces equipment wear and tear but also allows for relatively thorough filtration of impurities in the solution, preventing water pollution during subsequent liquid treatment. Details are as follows:

[0022] 1. The function of the heat insulation kit is the same as that of the temperature control jacket in the prior art, which is to prevent vanillin solution from precipitating in the shell due to temperature drop. Inside the shell, a filter press plate that can move vertically back and forth is designed so that the movement of the filter press plate can not only accelerate the flow of fluid through the filter assembly, but also take advantage of the tight fit between its edges and the shell, combined with the unidirectional flow characteristics of the inlet and outlet pipes, to realize the intake and discharge of vanillin solution. In this way, the coordination between the filter press operation and the fluid transportation operation is improved, and the use of general equipment is reduced, thereby reducing costs.

[0023] Furthermore, by designing the filter assembly to move synchronously with the filter press plate, the vertical movement of the filter assembly, combined with the spiral rod drive, enables the intermediate body to rotate synchronously, thereby providing an auxiliary cleaning effect on the residue in the intermediate filter screen. This avoids excessive clogging of the filter screen and increases filtration production capacity by reducing the frequency of manual cleaning.

[0024] 2. The vertical rod and multiple sets of horizontal rods are used as the connecting mechanism for the movement of the filter plate and the filter assembly. The distribution of the horizontal rods can drive the filter assembly to move in a traction manner or move back elastically. The movement of the horizontal rods in the space containing the filtered solution can also play a role in stirring and preventing sedimentation.

[0025] Furthermore, by designing the internal space of the filter press as a secondary solution transfer and containment space, the filter press can achieve the effect of drawing in and blowing out the filtered solution through changes in its internal pressure during the filtration process. The unique distribution of the first crossbar allows the blowholes on the surface of the crossbar to blow the drawn-in solution toward the filter screen of the filter assembly, thereby achieving a unique and effective backwashing effect in conjunction with the movement and rotation of the filter screen itself. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the external structure of Embodiment 1 of the present invention;

[0027] Figure 2 For the present invention Figure 1 Internal structure diagram;

[0028] Figure 3 This is a schematic diagram of the structure of the intermediate and ring bodies after separation in this invention;

[0029] Figure 4 For the present invention Figure 3 A schematic diagram of the structure viewed from below in the image;

[0030] Figure 5 This is a schematic diagram of the internal structure of Embodiment 2 of the present invention;

[0031] Figure 6This is a schematic diagram of the crossbar distribution structure of the present invention;

[0032] Figure 7 This is a schematic diagram of the internal structure of the crossbar of the present invention;

[0033] Figure 8 This is a schematic diagram of the cover plate distribution structure of the present invention;

[0034] Figure 9 This is a schematic diagram of the internal structure of the filter press plate of the present invention.

[0035] In the diagram: 1. Outer shell; 2. Insulation kit; 3. Filter press plate; 4. Drive shaft; 5. Input pipe; 6. Output pipe; 7. Elastomer; 8. Intermediate body; 9. Outer ring; 10. Vertical cylinder; 11. Twisted rod; 12. Vertical rod; 13. First horizontal rod; 14. Second horizontal rod; 15. Blow hole; 16. Suction hole; 17. Divider plate; 18. Cover plate; 19. Trigger rod. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figures 1-9 The present invention provides the following technical solution:

[0038] Example 1: In this example, in order to solve the problems existing in the prior art, such as Figures 1-2As shown, the device includes a housing 1 and an insulation kit 2 surrounding it. It also includes a filter assembly that is elastically slidably disposed inside the housing 1, and a filter press 3 located above the filter assembly. The filter press 3 is connected to a driver at the top of the housing 1 via a drive shaft 4. The filter press 3 reciprocates within the housing 1, drawing in solution between the filter press 3 and the filter assembly by changing the internal pressure of the housing 1 below the filter press 3, or allowing the solution to pass through the filter assembly and be discharged. Simultaneously, the filter press 3, during its movement, drives the filter assembly to move via a connecting mechanism, preventing impurities from clogging the filter assembly during reciprocating movement. The filter press 3, a mechanism for compressing fluid and accelerating its passage through the filter assembly, is designed as a component that incorporates liquid transport functionality. Specifically, the side surfaces of the filter press plate 3 are relatively sealed and slidably installed in the housing 1, while ensuring the airtightness of the internal space of the housing 1 below the filter press plate 3. This is easier than maintaining the overall airtightness of the filter. The filter press plate 3 is connected to the drive shaft 4 and the drive unit installed on the top of the housing 1 can be a screw drive mechanism controlled by a motor or a hydraulic mechanism, etc. When the filter press plate 3 moves upward, the overall space below it will be in a negative pressure state. Therefore, the vanillin solution will enter the area above the filter screen through the inlet pipe 5 with a one-way inlet valve. When the filter press plate 3 moves downward, the fluid will pass through the filter assembly and be discharged from the outlet pipe 6 with a one-way outlet valve, thereby achieving the effect of filtration and simultaneous fluid delivery.

[0039] While pressure filtration can improve filtration efficiency within a certain timeframe, the increased flow rate per unit time also leads to more frequent clogging of the filter elements. Considering the synchronous movement of the filter components mentioned in the above technical solutions, this solution... Figures 2-4The diagram discloses a scheme that utilizes the movement of a filter assembly to generate a cleaning effect. The filter assembly includes an intermediate body 8 with a filter screen and an outer ring 9 for rotatably mounting the intermediate body 8 and elastically sliding it within a housing 1. The lower end face of the intermediate body 8 is also connected to a rotating mechanism, which drives the intermediate body 8 to rotate within the outer ring 9 when the intermediate body 8 moves vertically. The rotation, combined with the movement of the intermediate body 8 itself, generates a filter residue cleaning effect. The reason why rotation and movement have a cleaning effect is that the cleaning of the intermediate body 8 is carried out simultaneously during a complete movement process of the filter press plate 3. In other words, during the reciprocating movement and rotation of the intermediate body 8, the amount of filter residue accumulated on its surface is not large. During the multidimensional motion, the filter residue on the filter screen surface remains relatively loose. The rotation process also serves as an auxiliary centrifugal treatment of the filter residue, thus achieving an auxiliary cleaning effect. Although this is less efficient than cleaning with tools when the machine is stopped, the above cleaning is based on minimal filter residue and a very high cleaning frequency, thus achieving a better anti-clogging cleaning effect. The rotating mechanism includes a vertical cylinder 10 fixedly installed on the lower end face of the intermediate body 8, and a twisted rod 11 threadedly connected to the vertical cylinder 10. The twisted rod 11 is fixedly installed in the outer shell 1. The connecting mechanism includes an elastic body 7 connected at both ends to the filter press plate 3 and the filter assembly, respectively. The elastic body 7, before and after being subjected to extreme stretching or compression... The movement of the filter press plate 3 drives the filter assembly to move synchronously. One way to achieve this is by designing the connecting mechanism as an elastic body 7 with an elastic structure. The elastic body 7 can be connected to the intermediate body 8 or the outer ring 9. The upward or downward movement of the filter press plate 3 can be divided into two stages. Taking downward movement as an example, the stage division is based on whether the elastic body 7 deforms. For instance, during the first stage of movement of the filter press plate 3, because the deformation force of the elastic body 7 is greater than the force required for the filter assembly to move, the elastic body 7 does not deform. During the second stage of movement, the elastic body 7 will continue to move. During the upward movement of the filter press plate 3, the process is similar to the downward movement. Alternatively, the deformation force of the elastic body 7 can be designed to be less than the force required for the filter assembly to move, so that the elastic body 7 will deform in one stage. During the phased movement, the filter assembly deforms first. Only after reaching the deformation limit, which is also the compression limit, will the filter assembly follow suit. This design creates a synchronous movement effect for the filter assembly, and the movement speed is related to the speed of the filter plate 3. Simultaneously, during the movement of the filter assembly, the vertical cylinder 10 installed on the lower end face of the intermediate body 8 will move synchronously at the top of the twisted rod 11. Therefore, under the action of the threaded transmission of the two, the intermediate body 8 containing the filter screen will rotate in the outer ring 9. Combined with the vertical movement of the entire filter assembly, the rotating intermediate body 8 will have a better auxiliary effect on the removal of the filter residue, thereby achieving an anti-clogging effect and ensuring the permeability of the filter assembly for high-purity solutions under high pressure.

[0040] Example 2: The solution disclosed in this example differs from the above examples, specifically as follows: Figures 5-6 As shown, the connecting mechanism includes a vertically sliding rod 12 installed in the outer ring 9. The top of the vertical rod 12 is connected to the filter plate 3, and the lower half of the vertical rod 12 is equipped with a first horizontal rod 13 and a second horizontal rod 14 distributed vertically. In the initial state, there is a gap between the first horizontal rod 13 and the filter assembly. When the filter assembly is in the initial state and the filter plate 3 is pressed down and moved, the filter assembly will not move. This ensures that the fluid can pass through the filter screen more efficiently than in Embodiment 1. During the upward movement of the filter plate 3, the initial movement will not cause the filter assembly to move. Therefore, the filter assembly and the filter plate 3 are closely connected. The space between them is relatively larger, which can accommodate more vanillin solution. During the subsequent movement, the first crossbar 13 contacts the lower end face of the filter assembly and generates a lifting force, so the subsequent filter assembly will move synchronously, so that the intermediate body 8 can move vertically and rotate synchronously to achieve the effect of auxiliary cleaning. Moreover, the synchronous movement of the first crossbar 13 and the second crossbar 14 can also play a certain role in stirring and preventing sedimentation. At the same time, corresponding heating mechanisms can be set inside the first crossbar 13 and the second crossbar 14 to achieve a better effect of preventing cooling and precipitation that would reduce the purity of the solution.

[0041] The solution disclosed in this embodiment can simultaneously achieve efficient filter cleaning in conjunction with the above embodiments, specifically as follows: Figures 7-9As shown, the first horizontal bar 13 follows the vertical bar 12 and is angularly distributed about the axis of the filter assembly. The first horizontal bar 13 is located below the filter screen of the intermediate body 8. That is, after the first horizontal bar 13 moves a certain distance, it will fit against the lower end face of the filter screen. The blowhole 15 on the surface of the first horizontal bar 13 is connected to the flow supply mechanism through the hollow structure of the horizontal bar. The flow supply mechanism generates a fluid transport effect through the movement of the filter plate 3, and the blowhole 15 is used to blow fluid from below the filter screen to backwash the filter screen. The suction hole 16 on the surface of the second horizontal bar 14 is connected to the flow supply mechanism through the hollow structure inside the horizontal bar and is used by the flow supply mechanism to absorb the filtered solution. The hollow structures inside the first horizontal bar 13 and the second horizontal bar 14 are respectively connected to the flow supply mechanism. The two unidirectional cavities within the vertical rod 12 are interconnected. These unidirectional cavities are used to transport the solution from the supply mechanism to the first horizontal rod 13, and to absorb the filtered solution or other fluids into the second horizontal rod 14 and into the supply mechanism. The internal space of the vertical rod 12 is separated by a partition plate 17 to form two unidirectional cavities, both of which are connected to the supply mechanism. The supply mechanism includes the internal space of the filter press plate 3 and a cover plate 18 elastically covering the top opening of the space. The upper end of the cover plate 18 is fixedly connected to the tail end of the trigger rod 19. The internal cavities of the vertical rod 12 are connected to the internal space of the filter press plate 3. Taking the initial state as an example, when the filter press plate 3 moves upward as a whole, the trigger rod 19 is not connected to the top of the outer casing 1 or the single-phase... When the independently established blocking mechanism comes into contact, the internal pressure of the filter plate 3 remains unchanged, and the fluid stored inside it also remains unchanged. This is because the fluid stored inside it only flows under a certain pressure, which corresponds to the state where the first crossbar 13 is not close to the filter screen. After the top of the trigger rod 19 touches the top, the continuous movement of the filter plate 3 will cause the cover plate 18 to press down through the trigger rod 19. Therefore, the internal space of the filter plate 3 will be compressed. Under a certain pressure, the fluid will enter one of the one-way spaces and enter the interior of the first crossbar 13, and finally be sprayed out from the blowhole 15 and directly act on the filter screen of the intermediate body 8. This, combined with the movement and rotation of the intermediate body 8, produces a comprehensive cleaning effect. The reason for prioritizing the use of filtered fluid is... The filter screen is rinsed to prevent temperature differences in the external fluid from interfering with the vanillin solution. This backwashing process can also be set up independently, reducing equipment costs. When the cover plate 18 moves back, it corresponds to the discharge stage where the fluid passes through the filter screen and enters the lower half of the internal space of the outer casing 1. Therefore, the suction hole 16 of the second crossbar 14 will be under negative pressure, drawing the fluid into the internal space of the filter press plate 3. The fluid can be the fluid remaining from a previous moving filtration cycle on the filter press plate 3, or it can be gas. Neither gas nor liquid affects the subsequent backwashing effect because the fluid will continue to enter the second crossbar 14 normally during continuous filtration. The heating mechanism designed in the two sets of crossbars can be an electric heating wire, etc.Alternatively, the hollow structure and suction holes 16 in the second horizontal bar 14 can be discarded, and the space in the vertical bar 12 that was originally connected to the second horizontal bar 14 can be connected to a heat source device, thereby achieving both cleaning and heat preservation effects.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A filter for purifying high-purity vanillin, comprising a housing (1) and a heat-insulating kit (2) distributed around its exterior, further comprising a filter assembly elastically slidably disposed inside the housing (1), and a filter press (3) located above the filter assembly, wherein the filter press (3) is connected to a driver at the top of the housing (1) via a drive shaft (4), characterized in that: The filter plate (3) moves back and forth in the outer shell (1). By changing the internal pressure of the outer shell (1) below the filter plate (3), the solution is drawn into the space between the filter plate (3) and the filter assembly, or the solution is discharged through the filter assembly. At the same time, the filter plate (3) moves through the connecting mechanism to drive the filter assembly to move, so that the filter assembly is not blocked by impurities during the reciprocating movement.

2. The filter for high-purity vanillin purification according to claim 1, characterized in that: The filter assembly includes an intermediate body (8) with filter elements and an outer ring (9) for rotating the intermediate body (8) and elastically sliding it in the outer shell (1). The lower end face of the intermediate body (8) is also connected to a rotating mechanism, which is used to drive the intermediate body (8) to rotate in the outer ring (9) when the intermediate body (8) moves vertically. The rotation, combined with the movement of the intermediate body (8), produces a filter residue cleaning effect.

3. The filter for high-purity vanillin purification according to claim 2, characterized in that: The rotating mechanism includes a vertical cylinder (10) fixedly installed on the lower end face of the intermediate body (8), and a twisted rod (11) threadedly connected to the vertical cylinder (10), wherein the twisted rod (11) is fixedly installed in the outer shell (1).

4. A filter for high-purity vanillin purification according to claim 3, characterized in that: The connecting mechanism includes an elastic body (7) with its two ends connected to the filter plate (3) and the filter assembly respectively. The elastic body (7) moves synchronously with the filter assembly before and after being stretched or compressed to its limit, and the movement of the filter plate (3) drives the filter assembly to move synchronously.

5. A filter for high-purity vanillin purification according to claim 3, characterized in that: The connecting mechanism includes a vertical rod (12) that is vertically slidably installed in the outer ring (9). The top of the vertical rod (12) is connected to the filter plate (3), and the lower half of the vertical rod (12) is equipped with a first horizontal rod (13) and a second horizontal rod (14) distributed vertically. In the initial state, there is a gap between the first horizontal rod (13) and the filter assembly.

6. A filter for purifying high-purity vanillin according to claim 5, characterized in that: The first horizontal bar (13) is distributed at the same angle as the vertical bar (12) about the axis of the filter assembly. The first horizontal bar (13) is located below the filter screen of the intermediate body (8). The blowhole (15) on the surface of the first horizontal bar (13) is connected to the flow supply mechanism through the hollow structure of the horizontal bar. The flow supply mechanism generates a fluid transport effect by moving the filter plate (3). The blowhole (15) is used to blow fluid from below the filter screen to backwash the filter screen.

7. A filter for purifying high-purity vanillin according to claim 6, characterized in that: The suction hole (16) on the surface of the second crossbar (14) is connected to the flow supply mechanism through the hollow structure inside the crossbar and is used by the flow supply mechanism to absorb the filtered solution.

8. A filter for purifying high-purity vanillin according to claim 7, characterized in that: The hollow structures inside the first crossbar (13) and the second crossbar (14) are respectively connected to the two unidirectional cavity structures inside the vertical bar (12), and the internal space of the vertical bar (12) is separated by a partition plate (17) to form two unidirectional cavities, both of which are connected to the flow supply mechanism.

9. A filter for purifying high-purity vanillin according to claim 8, characterized in that: The flow supply mechanism includes the internal space of the filter press plate (3) and a cover plate (18) that is elastically covered at the top opening of the space. The upper end face of the cover plate (18) is fixedly connected to the tail end of the trigger rod (19). The internal cavity of the vertical rod (12) is connected to the internal space of the filter press plate (3).

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