JPH07222903A - Granular medium filter - Google Patents

Abstract

PURPOSE: To transfer a granular material without using a large amount of carrier water or backwash water, or momentary high-flow rate by dividing a slope floor into plural separated channels, i.e., water courses, which run substantially in an inclined direction of the floor. CONSTITUTION: When granular active carbon 2 has consumed its adsorption capacity and has to be discharged, a discharge valve 6 is opened and then most of the active carbon are flown through a discharge part 5 from the filter together with water in gaps between the granules. The residual active carbon leaved are washed away by one set of water splinkling tubes 10. Each of water splinkling tubes 10 is supplied with water by successively opening each corresponding valve 11, so water is sprayed from the water splinkling tubes 10 toward the upper wall of the channel, whereby the residual active carbon is washed and flowed down on the inclined plane of the channel to the discharge part 5 to be discharged. Washing away of individual channel by each of the water splinkling tubes 10 can be conducted further effectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved particulate media filter which allows the transfer of particulate material with very small amounts of water.

[0002]

The particulate media filter of the present invention comprises a tank or vessel having a perforated or porous bed coupled to a collection system. This tank or vessel contains a granular medium, through which water is passed for filtration or adsorption. Sand filtration of water is one of the most common examples. In this case, a backflow must sometimes be made to wash away the solids trapped in the sand. It is also common practice to force air through the bed to agitate the particles during backflow (or backwash) to facilitate their cleaning action.

In such a filter device, for adsorbing impurities from water and acting as a filtration medium,
If granular activated carbon or other adsorbent material is used, the design must be such that the adsorbent particles can be easily removed when they are exhausted and the backwash water and air are always evenly distributed. I have to. Activated carbon is transported in a tank that can be pressurized or sucked, and is carried directly to the filter, so that refilling of the filter is easy. However, removal of depleted material is more difficult. It is even more difficult, especially when the last minute traces have to be removed from the filter. Large amounts of carrier water usually have to be used to completely remove the depleted material, and are often combined with long backflow. However, such a method requires a large amount of water, and the plant cannot obtain sufficient water, which is difficult.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a particulate material, such as activated carbon, after its adsorption capacity has been exhausted, without the use of large amounts of carrier water or backwash water or instantaneous high flow rates. The purpose is to provide a means for transferring the granular material.

[0005]

Therefore, according to the present invention, a filter using a particulate filter medium, such as a tank having a granular filter medium, the tank having a floor sloping toward a sump. In, there is provided a filter characterized in that the bed is divided into a plurality of separate channels or channels running substantially in the direction of inclination of the floor, each channel being individually washable.

[0006] The filter of the present invention is the same as British Patent Application No. 9204.
With a slightly sloping floor as described in No. 935.2.
Typically, the sump or sump at the bottom of the sloping floor is
It comprises one or more openings leading to a discharge tube which serves as the outlet for the filtered water and, if necessary, the particulate filter medium. Each of the openings leading to the discharge tube may be provided with an inverted trap as described in British Patent Application No. 92144414.6 to prevent clogging of particulate material during normal operation of the filter.

The inlet for backwash fluid, especially water and / or air, usually comprises a sloping floor. The backwash system is only designed to provide a sufficient time for the backwash to normally cleanse the particulate medium after one pass of filtration. If necessary, air purification will be performed.

The floor is divided into a plurality of separate, parallel channels by low dividing equipment such as walls or ribs that run substantially in the floor's slope direction. Each channel thus formed is typically above the upper end of the channel,
Water is supplied by a water inlet, for example a spray tube, located at a height above the highest level of particulate material in the normal operation of the filter. The water inlet can wash residual particulate material down each channel by sprinkling water against the wall at the upper end of the channel by each water inlet while discharging particulate material from the filter. A water supply device is provided. The width of each channel and each inlet is selected to match the resulting flushing water supply, so that the amount of water used during flushing is kept to a minimum. In this case, after most of the particulate material has been released,
One or more channels are individually rinsed,
And preferably each channel will be repeatedly flushed.

In one preferred embodiment, the filter of the present invention comprises, outside of this filter, a discharge and transfer system in the form of a circulation system. The circulation system includes a manifold having a first pump that pumps water along a manifold from a remote sump, a manifold that supplies a set of water inlets located above the upper end of the channel. From the point where the discharge pipe connects to the manifold at a point downstream of the point of water supply to the water inlet, the manifold being at a point downstream of the point where the discharge pipe connects to the manifold. And a second pump for pumping the material discharged from the filter through the discharge tube along the manifold to a receiving tank at the other end of the manifold opposite the remote sump. The tank is installed in such a position that excess water from the tank is returned to the remote sump.

The discharge valve of the discharge pipe is then opened when discharge from the filter takes place. Thus a major portion of the particulate material is flushed out with the water in the material gap (the pre-drainage filter contains the full amount of particulate material and holds up to normal levels of surface water). . A short burst of backwash (for only a few seconds) is carried out to re-flatten the material, if necessary, to prevent the formation of a hard-moving swirl of particulate material. Alternatively, depending on the type of granular material and floor type, air cleaning could be used instead of backwashing.

The discharged particulate material exits the discharge tube and flows into the manifold. Water is pumped from the first remote sump through the manifold, which dilutes and fluidizes the material. Thus a concentrated slurry of particulate material is diluted to a lower concentration, eg 20% by volume, which can be easily transported over long distances and then further pressed by a second pump to a receiving tank such as a silo or tanker. Then, the material transferred in this tank precipitates. Excess water flowing into the silo or tanker overflows or transfers to the sump where it is recycled.

After the majority of the particulate material has been discharged, the water inlets supplied by the manifold, for example the spray tubes, are each activated and the water is sprayed on the walls on each channel in sequence. Residual particulate material is washed away in each of the tilted channels and flows down into the discharge pipe and then along the manifold to the silo or tanker.

It will be readily appreciated that with the filter of the present invention, the amount of water used is significantly less than in conventional filter systems. By using separate water inlets above the divided channels of the sloping bed, residual particulate material is washed away by a series of separate water streams flowing down each channel. Further, by using the recirculation manifold system of the present invention, much of the water used is recirculated, with the only major loss of water being excess water overflow from the manifold sump.

[0014]

The invention will be better understood from the description of the preferred embodiment of the invention which follows with reference to the accompanying drawings.

In the embodiment shown in FIGS. 1 to 3, the filter 1 contains a granular activated carbon 2 supported on an inclined filter bed 3. A plurality of filter nozzles 21 project through the floor 3. The filter 1 is connected to a backwash water supply 8. The end section 4 of the floor slopes transversely to the delivery section 5. In order to prevent activated carbon from entering the delivery pipe during normal operation, the delivery section 5 may be protected by an inverted trap (not shown) as described in British Patent Application No. 92144414.6. The delivery tube is equipped with a discharge valve 6 and a dilution tube 7 is provided at the vent of the delivery tube to create a backflow and to add carrier water.

The sloping floor 3 comprises a low wall 9 rising at least as high as the top of the filter nozzle 21. These walls divide the filter floor 3 into a plurality of sectioned channels. One distribution pipe 10 is provided above each channel thus formed. These spray tubes 10 are mounted on the rear wall of the filter 1 at a height above the maximum level of the activated carbon 2 during normal operation of the filter 1. The spray pipe 10 is supplied with water from the manifold 11,
It is then shut off by the set of respective valves 12.

The granular activated carbon 2 consumes its adsorption capacity,
When it has to be discharged, the discharge valve 6 is opened, where most of the activated carbon flows out of the filter through the delivery section 5 along with the water in the interstices between the particles. The residual activated carbon that remains after most of the activated carbon has been released is then washed away by a set of spray tubes 10. Each sprinkling pipe 10 is successively supplied with water by opening the corresponding valve 11, where the water is sprinkled from the sprinkling pipe 10 against the upper wall of the channel, whereby the residual activated carbon is washed and the channel tilts. Sending part 5
It flows down to and goes out. Flushing individual channels with water from each sparging tube 10 is much more effective in flushing residual activated carbon than is possible with conventional large volumes of backwash water or the like.

In yet another embodiment of the present invention, a filter of the above type is emptied by a recirculation system as shown in FIGS. As shown in FIG. 4, the filter of the present invention is coupled to a recirculation system, such as the one shown schematically, with a manifold 15 having a remote sump or remote sump 13 at one end. Downstream of the sump or sump 13, a first pump 14 is provided which circulates water to the filter 1 (or a set of such filters). An orifice or throttling device 1 for deflecting water from the manifold 15 towards the spreading pipe 10 above the filter bed 3 when needed and towards the dilution inlet 7 when needed.
7 is provided in the manifold 15. As for the delivery pipe from the filter, the spray pipe 10 and the dilution feed unit 7 are the manifold 1
Manifold 15 at a point downstream from the point connecting to 5.
Connected to. A second pump 16 is provided on the downstream side of the connection point of the delivery pipe, and presses the water flow in the manifold 15 and pushes it into the silo 18 at the end of the manifold.

In use, water is pumped from sump 13 by first pump 14 through manifold 15. When the discharge valve 6 is opened, the granular activated carbon discharged through the delivery part 5 moves into the water stream in the manifold 15 and is diluted to a much lower concentration, eg 20% by volume, thus increasing its ease of transfer. Water containing activated carbon is manifold 15
Flow along and are pressed by the second pump 16 and transferred to the silo 18, where the granular activated carbon precipitates.
Excess water overflows from silo 18 and falls into sump 13, thus recirculating more water.

After most of the activated carbon has been released, the residual activated carbon is washed off by the water sprinkled from the sprinkling pipe 10 against the upper wall of each channel made by the rails 9 in the filter floor 3, which It flows down the channel to the delivery section 5 and then through the manifold 15 into the silo 18. The water in the manifold 15 is sent to the spray pipe 10 by operating the orifice or the throttle device 17.

Alternatively or as a variant (see FIG. 5), the water containing the released activated carbon could be transferred to a waiting road tanker 19. If a road tanker 19 is used, this tanker is allowed to park on the drain 20 and excess water is dropped through the drain 20 into the sump 13.

[Brief description of drawings]

FIG. 1 is a side cross-sectional view of a filter according to one embodiment of the present invention.

2 is a plan view of the filter of FIG. 1. FIG.

FIG. 3 is a cross-sectional view of the filter taken along the line AA ′ in FIG.

4 is a side sectional view of the filter of FIG. 1 coupled to a recirculation manifold system leading to a silo.

5 is a drawing showing the end of the manifold system of FIG. 4 attached to a road tanker rather than a silo.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 filter 2 granular activated carbon 3 filter bed 5 delivery part 6 discharge pipe 7 diluting pipe 8 backwash water supply part 9 channel wall 10 spray pipe 11 manifold 13 sump 14 first pump 15 manifold 16 second pump 17 throttling device 18 silo 19 road Tanker 20 Drain 21 Filter / Nozzle

Claims (5)

[Claims] 1. A filter that uses a particulate filter medium, such as a tank that holds a granular filter medium, the tank having a floor that slopes toward a sump, wherein the bed substantially slopes the floor. A filter characterized in that it is divided into a plurality of separate channels running in a direction, each channel and the wall being able to be washed off individually at the upper end of the channel. 2. The filter of claim 1, wherein the floor is divided into a plurality of separate parallel channels by low walls or ribs. 3. Each channel is fed by a water inlet located above the upper end of the channel and at a height above the highest level of the particulate material during normal operation of the filter. The filter according to claim 1 or 2. 4. The water inlet comprises a water supply such that each channel and wall can be flushed at the upper end of the channel after most of the particulate material has been discharged. The filter according to any one of items 1 to 3. 5. The filter comprises a discharge and transfer system external to it in the form of a circulation system, the circulation system having a first pump that pumps water along the manifold from a remote sump, of the channel. Tapping from the manifold that supplies water to the set of water inlets installed above the upper end, and a discharge pipe connected to the manifold at a point downstream from the point of water supply to the water inlets, The manifold comprises a second pump at a point downstream from the point where the discharge tube connects to the manifold, whereby the material discharged from the filter through the discharge tube is along the manifold and the remote sample. To the receiving tank at the other end of the manifold on the other side of the manifold, the tank being positioned such that excess water from the tank is returned to the remote sump. The filter according to any one of 1.