RU2527216C1 - Discharge strainer - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: filter comprises vertical cylindrical housing with spherical cover and bottom divided by horizontal web into top and bottom chambers. Top chamber is filled with floating granulated material while bottom chamber is filled with heavy sandwiched bed. Water to be processed flows through top chamber mid distributor to be filtered from bottom to top via floating granulated bed to remove coarsely dispersed impurities. Partially cleaned water is collected in top distributor and directed via central vertical pipe into bottom chamber mid distributor. Water in bottom chamber is filtered from top to bottom via heavy sandwiched bed and, after removal of finely dispersed impurities, it is discharged via bottom distributor.

EFFECT: compact design, higher efficiency of cleaning.

3 cl, 1 dwg

Description

The invention relates to the field of water treatment and can be used in energy, chemical and other industries for the purification of natural and wastewater from suspended, colloidal and organic impurities, iron and manganese compounds, as well as for protecting membrane elements and ion-exchange resins of reverse osmosis and ion-exchange filtering systems and extending their lifespan.

Known pressure filter (FP3-4N) with floating granular polystyrene loading and equipped with upper and lower distribution devices. The piping for the treated and flushing water is connected to the upper drainage device. The purified water drainage pipe is connected to the middle drainage device through a polystyrene foam trap (see Manual on the Design of Facilities for Water Treatment and Preparation for SNiP 2.04.02-84 M. TsITP, 1989, p. 68).

The disadvantage of this filter is its low performance, since water is purified in a downward flow through a floating load. When the load increases due to an increase in the amount of water supplied to the water treatment, the polystyrene foam loading loosens, which reduces the efficiency of water treatment.

A device for purifying river water is known, which undergoes preliminary coagulation with aluminum sulfate. The device includes a non-pressure clarifier and a pressure mechanical filter with a two-layer heavy load. The load consists of the upper layer of hydroanthracite and the lower layer of quartz sand (see IL Shorin et al. A new look at obsolete pre-treatment equipment for chemical water treatment. “Energy Saving and Water Treatment”, No. 5 (49), 2007, p. 17) .

The disadvantage of this device is the low reliability of the non-pressure clarifier to maintain a weighted slurry regime of the contact medium, especially when changing its performance.

To simplify and reduce the cost of the preliminary stage of surface water treatment, contact coagulation with aluminum salts on a mechanical filter is used instead of a clarifier with a suspended layer. However, the rapid contamination of the two-layer loading in this case will lead to a decrease in the productivity of the device and an increase in the flow rate of the wash water.

A device for cleaning liquids is known (RF patent No. 2106897, class B01D 37/00; B01D 24/18, publ. 03/20/1998), containing a housing separated by a Central channel on the prefilter with a floating load and a filter with heavy loading. As a floating filter load, polystyrene foam (polystyrene) is used, which traps flocs of impurities from the treated water.

The disadvantage of this installation is the low dirt capacity of a single-layer heavy load, the low productivity of a pressureless filtering system, the complicated and unreliable design of the device to keep the floating load in the flooded state of the prefilter, especially large filters, and the uneven distribution of wash water over the area of the floating prefilter.

The closest technical solution is the installation for two-stage water purification by filtration (RF patent for utility model No. 75160, class B01D 24/18, C02F 1/28, publ. July 27, 2008), containing two pressure filter housings connected by a pipeline through overhead switchgears. The first filter housing is filled with a floating granular charge, the lower switchgear of which is connected to the pipeline for supplying purified water and drainage of flushing water. The second filter housing is filled with a two-layer heavy load, the lower switchgear of which is connected to the pipeline for discharging purified water and supplying washing water. The process uses a counter-current cleaning technology, in which the purified water is supplied to the lower switchgear of the first filter housing, filtered through a layer of floating granular charge, partially purified water is discharged through the upper switchgear and then enters the second case through the upper switchgear, filtered through a two-layer heavy load and purified water is discharged through a lower switchgear. As the filter loads are contaminated, they are loosened by washing in the opposite (counterflow) direction.

The disadvantage of the design is the large area of the room needed to accommodate two pressure filter housings, as well as increased costs for equipment, construction and maintenance.

The objective of the invention is to reduce capital costs by ensuring the compactness of the equipment, halving the room area, as well as reducing construction and operating costs. At the same time, the efficiency of water purification is maintained using the advantages of countercurrent technology.

To achieve these results, the pressure filter contains a vertical cylindrical housing with a spherical cover and a bottom, upper and lower switchgears with filter elements, a pipeline with shut-off and control valves for supplying purified water and drainage of wash water, a pipeline with shut-off and control valves for supplying wash water and drainage of purified water connected to the lower switchgear, while the housing is hermetically separated by a horizontal partition into upper and lower amers and is equipped with a central vertical pipe connected by the upper end to the upper switchgear and passing through a horizontal partition into the upper part of the lower chamber, and two middle switchgears equipped with filter elements, one middle switchgear is located at the base of the upper chamber and connected to the cleaned supply pipe water and drain water, and another medium distribution device is located in the upper part of the lower chamber and is connected the lower end of the central vertical pipe, wherein the layer of floating granular loading is located in the upper chamber, and a layer of a multilayer heavy load - in the lower chamber.

The heights of the layers of the floating granular load and heavy multilayer load are 50-80% of the heights of their chambers, to ensure the expansion of the load during backwashing with water.

As filter elements of the upper, lower and two middle distribution devices, well-known slotted distribution pipes or slotted caps are used.

The width of the slots of the filter elements of the distribution devices is selected from the condition that there is no removal of filter loads and the size of the pollutants present in the treated water, namely for the upper switchgear in the range of 0.5-1.5 mm, for the middle switchgear of the upper chamber in the range of 1- 3 mm, for the middle switchgear of the lower chamber in the range of 1-5 mm and for the lower switchgear in the range of 0.2-1.0 mm.

The use of two stages of water purification with the advantages of a pressure filter and countercurrent water purification technology in one filter housing of the proposed design allows us to halve the installation area, reduce the cost of equipment and construction and installation work without reducing the filter performance and reducing the quality of purified water.

It is known that in one filter housing there is a combination of two stages of water purification with placement on the first stage of a floating load, and on the second stage of a heavy filter load (RF patent No. 2256481, class B01D 24/16, B01D 24/46, published on July 20, 2005 .). However, the known pressure head two-stage filter does not work according to the countercurrent technology system and requires additional collector and pipelines for supplying and withdrawing washing water, which complicates the device and increases the consumption of washing water. The absence of distribution devices for supplying water to the filtering surfaces does not provide uniform filtration over the entire volume of the load, which reduces the quality of water treatment.

The figure shows a diagram of the proposed two-stage pressure filter.

The two-stage pressure filter contains a vertical cylindrical housing 1 with a spherical cover 2 and a bottom 3, upper 4 and lower 5 switchgears with filter elements. The housing 1 is hermetically divided by a horizontal partition 6 into the upper chamber 7 and the lower chamber 8. The upper chamber 7 is loaded with a floating granular load 9 (granule size 2-8 mm), the lower chamber 8 is loaded with a heavy multilayer load 10. The housing 1 is provided with a central vertical pipe 11, connected by the upper end to the upper switchgear 4 and passing through a horizontal partition 6 to the upper part of the lower chamber 8. At the base of the upper chamber 7 there is a middle switchgear 12 with filter elements entrances connected to the pipeline 13 with shutoff-regulating valves for the supply of purified water 14 and valves for the removal of washing water 15. In the upper part of the lower chamber 8 there is a middle switchgear 16 with filter elements connected to the lower end of the central vertical pipe 11. A heavy multi-layer loading consists from the lower supporting layer of gravel 17 (granule size 2-5 mm), the middle layer of quartz sand 18 (granule size 0.3-2 mm) and the upper layer of hydroanthracite 19 (granule size 1-4 mm). The pipeline 20 is connected to the lower switchgear 5 with filter elements and is equipped with shut-off and control valves for the removal of purified water 21 and the supply of washing water 22.

The heights of the layers of the floating granular load 9 and the heavy multilayer load 10 are 50-80% of the heights of their chambers to ensure the expansion of the load during backwashing with water.

As filter elements of the upper 4, lower 5 and middle 12 and 16 distribution devices, well-known slotted distribution pipes or slotted caps are used. The width of the slots of the filter elements of the switchgear is selected from the condition of the absence of removal of granules of filter loads and the size of the pollutants present in the treated water, namely for the upper switchgear 4 in the range of 0.5-1.5 mm, for the average switchgear 12 in the range of 1-3 mm, for the average switchgear 16 in the range of 1-5 mm and for the lower switchgear 5 in the range of 0.2-1.0 mm

The filter works as follows.

The pressure filter operation involves two modes: water purification and washing the filter load from contaminants.

For cleaning, water is supplied through a pipe 13 with an open shut-off and control valve 14 to a middle switchgear 12 with filter elements (slot widths in the range of 1-3 mm) of the upper chamber 7. Then, the water is evenly distributed over the area and filtered in the direction from the bottom up through the layer floating load 9. An inert material (granule size of 2-8 mm), whose grain density is less than the density of water, is used as a filter load. Layer floating load 9 delays coarse, suspended and colloidal substances from the source water. Partially purified water enters through the upper switchgear 4 with filter elements (slot width in the range of 0.5-1.5 mm) and the central vertical pipe 11 into the middle switchgear 16 with filter elements (slot width in the range of 1-5 mm) lower chambers 8. For fine purification of water from fine contaminants, it is fed to a multilayer heavy load 10 and filtered from top to bottom through a layer of coarse hydroanthracite 19 (granule size 1-4 mm) and a layer of fine-grained quartz sand 18 (granule size 0.3-2.0mm). The clarified and purified water through the lower switchgear 5 with filtering elements (slot widths in the range of 0.2-1.0 mm) of the lower chamber 8 is fed into the pipeline 20 with the shut-off and control valves 21 open and discharged to the consumer.

If the filter materials are contaminated (differential pressure control), they are backwashed with water.

Turn off the filter from the water treatment mode. To do this, close the shut-off and control valves 14, 21 and stop the flow of purified water and the removal of purified water. Then, the shut-off and control valves 15, 22 are opened and washing water is supplied to the pipeline 20, which passes through the lower switchgear 5 from bottom to top through a layer of gravel 17, a layer of quartz sand 18 and a layer of hydroanthracite 19. During washing, a layer of quartz sand 18 and a layer of hydroanthracite 19 expand by 20-50% of the height of the lower chamber 8, providing effective cleaning of granules of quartz sand and hydroanthracite. The supporting layer of gravel 17 during washing does not expand, but ensures a uniform flow of washing water. Next, the washing water is discharged from the lower chamber 8 through the middle distribution device 16 of the lower chamber 8 and is directed to the upper chamber 7 through the central vertical pipe 11 and the upper distribution device 4. The flow in a top-down direction flushes the layer of the floating granular load 9. At the same time, during washing the layer of the floating granular charge 9 expands by 20-50% of the height of the upper chamber 7, providing effective cleaning of the granules of the floating material. The washing water is removed through the middle switchgear 12 of the upper chamber 7 and then through the pipe 13.

Given the need to expand the layers of the floating granular load 9, quartz sand 18 and hydroanthracite 19 during backwashing with water, the height of the layers of the floating load 9 and heavy multilayer load 10 are 50-80% of the heights of their chambers.

Thus, the proposed invention allows to significantly reduce capital costs, rationally use the room’s space, conduct a process of coarse and fine water purification in one filter housing, ensure high water purification performance and save wash water through the use of countercurrent technology.

Claims (3)

1. A two-stage pressure filter containing a vertical cylindrical housing with a spherical cap and a bottom, upper and lower switchgears with filter elements, a pipeline with shut-off and control valves for supplying purified water and drainage of wash water, a pipeline with shut-off and control valves for supplying wash water and drainage of purified water connected to the lower switchgear, a layer of a floating granular load and a heavy multilayer load, characterized in that the housing hermetically divided by a horizontal partition into the upper and lower chambers and equipped with a central vertical pipe connected by the upper end to the upper switchgear and passing through the horizontal partition to the upper part of the lower chamber, and two middle switchgears equipped with filter elements, one middle switchgear is located at the base the upper chamber and is connected to the pipeline for supplying purified water and drainage of washing water, and the other medium Flax device is placed on top of the lower chamber and is connected to the lower end of the central vertical pipe, wherein the layer of floating granular loading is located in the upper chamber, and a layer of a multilayer heavy load - in the lower chamber. 2. The two-stage pressure filter according to claim 1, characterized in that the heights of the layers of the floating load and heavy multilayer loading are 50-80% of the heights of their chambers. 3. The two-stage pressure filter according to claim 1, characterized in that the width of the slots of the filter elements for the upper switchgear is 0.5-1.5 mm, for the middle switchgear of the upper chamber - 1-3 mm, for the middle switchgear of the lower chamber - 1-5 mm and for the lower switchgear - 0.2-1.0 mm.