JPH0127765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to the field of pressure filtration in which filtrate flows through the porous surface of a filtration element into an internal cavity, and more particularly to the field of pressure filtration in which filtrate flows through a porous surface of a filtration element into an internal cavity, and more particularly to A new and improved method and apparatus for cleaning.

In this invention, the outlet manifold of a pressure filter is spring loaded and vibrates along a vertical axis to separate the filter cake from the filter tubes depending from the manifold.

Hitherto, it has been known to apply vibrational waves to filter elements such as filter tubes and filter leaves in order to remove filter cake deposited during filtration operations. When the cake is dried before the vibratory operation, the operation is referred to as dry cake evacuation, and operations while the cake is wet or contain liquid are commonly referred to as wet cake ejection. US Pat. Nos. 3,212,643 and 3,867,291 disclose the past use of shock waves to remove filter cake from filter elements.

Although the vibrating devices disclosed in the above-referenced US patents and heretofore known have been widely and satisfactorily used, in many cases there has been an element of faster and more complete cake removal than previously attempted.

Accordingly, in the present invention, the filter cake is dried and then the filter element is reciprocated or vibrated in a direction parallel to the surface on which the cake is deposited. The filtration element is then kept vibrating while filling the filtration tank with filtrate to thoroughly wash out any solids trapped in the pores of the porous surface of the filtration element.

Also, in the present invention, the filtration element is supported in a vertical position by a horizontally disposed outlet manifold that is spring-loaded within the tank of the filter. A vertically oriented shock wave is thus applied to the manifold, thereby shaking the filter cake from the filtration element. In a preferred embodiment of the invention, the filtration elements are tubular and depend from a manifold to which a number of the elements are rigidly attached. Also inside the tank is an air-operated vibration shocker mounted directly on the manifold. In another embodiment of the invention, the impactor is located above the tank and connected to the manifold by an impact rod extending through a seal opening in the top of the tank and preloading the manifold.

FIG. 1 shows a pressure filter 10, the main element of which is a generally cylindrical pressure tank 1.
It has 2. The pressure tank has a liquid inlet 14 for supplying filtrate to the filter and a liquid outlet 16 for exiting the filter. tank 1
The bottom wall of 2 is sloped and communicates with a drain opening 18, and the tank 12 has an air inlet and outlet opening 20 at the top which opens to the top of the tank through a cover 22.
have. As shown, the cover 22 is sealingly secured to the tank by a number of bolts 24.

An outlet manifold 26 having passageways 27 is provided near the top of tank 12 and supports a number of tubular filtration elements 28 suspended from the manifold. The manifold has a central header from which a plurality of side portions extend as shown, for example, in U.S. Pat. No. 3,244,286. In order to maintain the filtration elements 28 substantially parallel, the elements 2
A tubular spacer 30 is provided below 8. This spacer is US Patent No. 3244286 and US Patent No. 348502.
or any other suitable format. Spacer 30 is preferably suspended from manifold 26 to facilitate removal of the spacer from the tank along with the manifold and also to filter element 28.
This makes it easy to incorporate them into However, it can also be attached to the tank if desired. If the filter element is fairly short, the spacer 30 can be omitted altogether.

The filtration element may be of any suitable construction as is well known by those skilled in the art, having a rigid core surrounded by perforated filter media to define a cavity within the filtration element. The cavity communicates with a passageway 27 in the outlet manifold 26 via a tubular fitting 32.
The core may have an opening only near the bottom, as in the filter tubes described in U.S. Pat. It includes an open bottom perforated tube extending from the outlet to a location near the bottom. In either case, the filtrate flows down through the perforated surface to the bottom of the tube and then up through the tube to the outlet manifold at the top. Fitting 32 is preferably a short rigid tube that extends upwardly from the filter tube and threads into an auxiliary opening in the bottom of the manifold. The fitting thus communicates the cavity in the outlet manifold to the central passageway through the filtration element and provides a rigid connection between the filtration element and the manifold 26, which is itself a rigid structure.

Passages within the outlet manifold 26 are connected to the effluent outlet 16 by conduits 34. As will be discussed below, the manifold is movably mounted within tank 12 so that conduit 34 is at least partially flexible so as not to inhibit vertical movement of the manifold.

As best seen in FIG. 2, manifold 26 includes a plurality of radially extending brackets 36, preferably three (only one shown in FIG. 2). Each bracket has a vertical hole 38 extending therethrough.
It has a horizontal flange 37 with a horizontal flange 37. A plurality of angle brackets 40 are welded to the interior wall of the tank at locations corresponding to brackets 36. Each bracket 40 has a horizontal flange 41 with a threaded hole 42 therethrough. bolt 4
4 extends loosely through the hole 38 and is screwed into the hole 42. The upper coil spring 46 is attached to the flange 3
7 and a lower coil spring 48 is positioned below the flange 37. Spring 48 is held compressed between flanges 37 and 41 to hold the lower edge of manifold 26 slightly above flange 41 during filtration operations. The spring 46 is compressed and held between the flange 37 and the washer 50.

In FIG. 1, a vibration shocker 52 is mounted within the filtration chamber to the manifold 26 and is adapted to impose a vertical shock wave on the manifold 26 and the filtration element 28 connected thereto. The vibration impactor 52 is welded to the manifold as shown or rigidly attached thereto by bolts or other means. Vibratory impactor 52 may be of any suitable type, but is preferably of the pneumatic type as shown in US Pat. No. 3,212,643, which produces relatively high frequency vibrations. To this end, a pair of air tubes 54, 56 are connected to the impactor 52 and connected through the cover 22 to a suitable air control valve and for controllably operating the impactor 52 to vibrate the manifold 26 and filter element 28. Extending to a source of high pressure air (not shown). Only one impactor 52 is shown within the filter 10, and it is mounted in the center of the outlet manifold 26 on the theoretical longitudinal axis of the filtration tank. However, multiple impactors may be used if necessary.

To better understand filter 10, its operation will be described. First, drain opening 18 and outlet 16
and the air opening 20 is opened to the atmosphere. The filtrate is pumped into the filtration chamber through inlet 14 to fill the tank. The air opening 20 is then closed and the outlet 16 is opened. This causes the filtrate to flow through the filter element 28, which has a porous layer of pre-coated material such as diatomaceous earth disposed on the outer surface of the filter element 28. The filtrate generally flows through the filtration element until the precoat layer reaches a predetermined thickness. This filtration element is connected to a conduit in which filtrate flows into the tank through an inlet 14 and purified effluent exits the tank through an outlet 16. As the filtrate flows into the cavity within the filter element, solids trapped therein are deposited on the outer surface of the porous filter cake on the filter element.
When the filter cake becomes thick enough to interfere with the effective operation of the filter element, the filtrate inlet tube is closed and the filter element is removed. At this time, open the bottom drain pipe and drain the filtrate from the filtration chamber. At the same time, high-pressure air is supplied into the room from the air opening 20, and the outflow water outlet 16 is left open. Preferably the air is maintained throughout this drainage.
A high pressure is supplied to the chamber, which prevents pressure drop in the filter cake and prevents premature disintegration of the cake from the filter element. Air thus flows through the cake and removes moisture from the cake. Air flow is then stopped during this draining operation. Exit 16
As long as the filter is below the manifold 26, liquid will not flow back into the filtration element. If desired, Leaching Liquid or the like can then be fed into the tank and passed through the cake. After soaking, the cake is again air-dried as described above. Next, the impact machine is activated to apply impact or vibration to the manifold 26 and the filter element 28 on which the filter cakes are stacked. As a result, the accumulated cake falls to the bottom of the tank and is discharged from the drain opening 18 to the outside of the filter.

The above process is then repeated and the filter is returned to online operation. During the next filling step, the impactor continues to vibrate the filter element until it is immersed in liquid. This is to wash out solid matter trapped in the gaps in the perforated surface of the filter element.

Conduit 34 continues to the bottom of manifold 26. This allows the manifold 26 to drain completely during the cake drying process. Therefore, air opening 2
No liquid flows back into the filter element when the zero is closed at the end of the cake drying process. If the outlet section from the manifold is located above the bottom wall of the passageway of the outlet manifold, some of the runoff water will flow back into the tube, possibly causing movement of the cake bottom making cleaning of the cake difficult. Probably.

FIG. 3 shows another embodiment of the invention. Here, springs 46, 48 are replaced by a pair of resilient sleeves 60, 62 made of rubber or other suitable material compatible with the substance being filtered.

FIG. 4 shows yet another embodiment, in which the flexible conduit 3
4 has been replaced by a telescoping connection allowing relative vertical movement between the outlet manifold and the filtration tank. As shown, the liquid outlet 16 extends horizontally into the tank and has an upwardly curved inner end 6.
6 includes a rigid tube 64 having a diameter of 6. A rigid tube 68 depending from the manifold 26 is telescopically fitted onto the inner end 66 and an elastomeric O-ring 70 resting in an annular groove near the top of the inner end 66 extends over the tube 68. It is in pressure contact with the inner surface of. Vertical vibrations of the manifold and filtration elements are thus created by actuation of the vibration impactor 52. Additionally, removal of the manifold from the tank is facilitated by such a telescoping seal connection to the effluent outlet.

FIG. 5 shows yet another embodiment, in which the vibration impact machine 5
2 is placed outside the filtration tank. According to this embodiment, a vibration impactor 52 is rigidly attached to the upper end of a vertical bar 74 having a rigid pad 76 at its lower end. Pad 76 is preloaded against the top surface of manifold 26. This preload is the impact machine 5
2 and the elastic force of the coiled spring 78 compressed between the cover 22 and the collar 80 fixed to the rod 74. Collar 80 is screwed onto rod 74;
The contact pressure between the pressure vibrating pad 76 and the manifold 26 can be adjusted. Other adjustment methods can be used if necessary. There is only one in Figure 5.
Although only one is shown, a plurality of coiled springs 82 each rest on the bracket 40 and are attached to the manifold 26.
and the cooperating filtration element 28 are supported floatingly. A diaphragm-type seal 84, such as that shown in U.S. Pat. No. 3,212,643, provides the necessary seal between the rod 74 and the cover 22 of the filtration tank. In this embodiment, the manifold and tube assembly floats between springs 78 and 82, so that the vibrations imparted to the manifold and filtration elements during the vibration process are not damped. Preferably, the upper and lower springs are selected such that the vertical force on the manifold is substantially the same, thereby causing the manifold to levitate and providing a vibration shock wave with one or more relatively small vibration shockers. be done.

In a preferred embodiment of the invention described herein:
It has a filter tube that vibrates vertically at a frequency of 2500 to 4500 cycles per minute (this range is not considered critical). This method of spring mounting the outlet manifold can be used with filter leaves.
Additionally, in some applications, horizontally oriented shock waves are applied to the manifold to cause lateral vibration of the filter tubes or leaves.

The outlet from the manifold is below the bottom of the manifold to completely drain the manifold during this cake drying operation as air or other gases pass through the cake. However, other methods for completely draining the manifold can also be used.

Although the invention has been described with respect to specific embodiments thereof, many changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.
All changes and modifications that fall within the spirit and scope of the invention are intended by the appended claims.

[Brief explanation of drawings]

FIG. 1 is a partially sectional elevational view of a pressure filter embodying features of the present invention, and FIG. 2 is an enlarged sectional view showing the filter of FIG. 1 with the outlet manifold supported by a spring. 3 is a partial cross-sectional view showing an alternative method of attaching the outlet manifold; FIG. 4 is a partial cross-sectional view showing an alternative method of attaching the outlet manifold to a filter outlet fitting; FIG. 5 is a partial cross-sectional view showing an alternative method of attaching the outlet manifold to a filter outlet fitting It is a broken sectional view of the pressure filter which constitutes a specific example. Explanation of symbols, 10: Pressure filter, 12: Pressure tank, 14: Fluid inlet, 16: Fluid outlet, 18:
Drain opening, 20: Air opening, 22: Cover, 2
6: outlet manifold, 27: passageway, 28: filtration element, 30: spacer, 32: tubular fitting, 34:
Conduit, 36, 40: Bracket, 37, 41: Flange, 38, 42: Hole, 46, 48: Spring, 5
2: Vibration impact machine.

Claims (1)

[Scope of Claims] 1. A filtration tank surrounding a filtration chamber, a fluid inlet opening in said tank for introducing filtrate into said chamber, and a rigid, generally flat, tubular interior passageway. a header manifold having a header manifold, a spring supporting the manifold in the chamber, an outlet for water effluent from the tank, a conduit connecting the passageway to the outlet, and a hole each having a cavity therein. a plurality of filtration elements each having a filter element fixed to the header manifold at one end, the cavity communicating with the passageway and parallel to each other, the outer surface of the filter element facing the surface of the header manifold; A filter comprising a vertically extending filtration element and a vibration impactor connected to the manifold to urge the manifold in a direction parallel to the outer surface of the filter media. 2. The filter according to claim 1, wherein the filtration element is tubular and is suspended from the manifold. 3. The filter according to claim 2, wherein the vibration shocker is placed in the tank. 4. The filter of claim 3, wherein the vibration shocker forces a vertical shock wave onto the manifold and filtration element. 5. The filter according to claim 4, wherein the vibration impactor is supported by a manifold. 6. The filter according to claim 1, wherein the conduit is a flexible tubular member. 7. The filter of claim 1 comprising first and second tubular members telescopically fitted together with conduits connected to the manifold and the outlet, respectively. 8. The filter of claim 2, wherein the first spring supports the manifold within the tank and the second spring forces the manifold towards the first spring. 9. The filter of claim 8, wherein the vibration impactor is above the manifold, and wherein the spring forces the vibration impactor into contacting relationship with the manifold. 10. The filter according to claim 9, wherein the vibration shocker is at least partially located outside the tank. 11. The filter of claim 10, further comprising means for adjusting the relative force exerted on the manifold by the spring. 12. Claim 12, wherein the vibration shocker has a vertically arranged rigid rod extending into the room through an opening in the top of the tank, and a hermetic seal provided between the rod and the tank. The filter according to item 11. 13. A method for removing filter cake from the surface of a filtration element mounted on a rigid outlet manifold in a filtration tank, the manifold being mounted on a spring within the tank such that the manifold can be moved relative to the tank. and repeatedly impinging a manifold in a direction parallel to the surface of the filtration element to exert a shear force between the filtration element and the cake to separate the filter cake from the filtration element. 14. The filtration of claim 13, wherein the step of impulsing the manifold in a direction parallel to the surface of the filtration element is carried out by a vibration shocker mounted on the manifold for applying vibration shock waves to the manifold. Cake removal method.