RU2064811C1 - Filter for water purification - Google Patents

Abstract

FIELD: chemical engineering. SUBSTANCE: filter has a housing divided by vertical partitions with water permeable holes into sections filled with filtering load. Flow-through chambers are disposed under sections. Filter also has a drain-distributing cavity and slime pipes. The latter are equipped with uprights having sink-holes located at the level above mark of charge expansion during washing. Feeding pipe is attached to the first and last sections. Drain pipe is attached to cavity, "Л" shaped bent and is equipped with air escape valve and non-return valve. EFFECT: higher efficiency. 1 cl, 2 dwg

Description

 The invention is intended for clarification, deferrization and integrated water treatment, can be used in drinking water preparation technologies, as well as in environmental protection systems for industrial wastewater treatment.

 Known water treatment device (V. Ovodov. Agricultural water supply and watering. M. "Kolos", 1984, p. 248, Fig. 2.46), containing a housing filled with filter loading, a drainage distribution device, inlet, outlet and mud pipes connected to the walls of the housing.

 A disadvantage of the known water purification device is, when these devices are connected in parallel and the filtrate is fed from one to another, the quality of the filtrate is deteriorated due to the fact that the total flow of water supplied to the clarification does not decrease under these conditions, but is redistributed among the devices remaining in operation. This leads to their overload, and, consequently, to a deterioration in the quality of the filtrate, if you do not take any appropriate technical measures.

 A water treatment device is known (USSR Patent No. 1787042, class B 01 D 29/56, 1991), comprising a housing with a lid, divided into a number of sections by partitions with culverts at their upper ends and filled with a filter load, flow chambers attached to the lower parts sections, a drainage distribution device located under the sections, and the inlet, outlet and equipped with gates mud pipes connected to the walls of the housing. This device is taken as a prototype.

 The disadvantages of the prototype include the need to stop supplying purified water to it when washing at least one of the sections. Otherwise, laundered contaminants of high concentration will enter the subsequent sections, which will impair the quality of the filtrate. The presence of partitions of various heights complicates the design, and the presence of a shut-off device at the inlet to periodically stop the supply of purified water reduces the reliability of the prototype in operation.

 The aim of the invention is to improve the quality of the filtrate, simplify the design, increase reliability in operation.

 Figure 1 schematically shows a filter for water purification in the washing mode of the first section; figure 2 part of the flow chamber.

 The filter for water purification comprises a housing 1, divided by partitions 2 with culverts 3 at their upper ends into a series of sections arranged in series 4, a filter load 5 located in sections, flow chambers 6 attached to the lower parts of the sections, and a drainage distribution device made in the form of a common horizontal cavity 7, communicating with flow chambers. The inlet pipe 8 is connected in the first and last sections, the outlet pipe 9 is vertically L-curved and equipped with a plunger 10 for discharging air when it is filled with water and a non-return valve 11. The mud pipes 12 are equipped with risers 13 with funnels 14 located at a level above the mark expansion of loading during flushing and closures 15.

 Flow chambers 6 serve to exclude the influence of flow swirls in the drainage-distribution cavity on the dirt-holding ability of the filter load 5 in its lower part and can have two parallel horizontally mounted lattices 16, the space between which is filled with gravel with a particle diameter decreasing towards the middle of the layer.

 Instead of risers 13 with funnels 14, mud pipes 12 can be equipped with siphons with water inlets at a level above the mark of loading expansion when washing it and with a peak above the L-shaped pipe and culverts 3 of partitions 2, this ensures that the siphon is automatically charged with water before washing and discharged state during filtration before washing, i.e. in this embodiment, the installation works automatically (while the shutters 13 can be excluded from the device).

It was experimentally established that for optimal filter operation, it is necessary that the number of sections be determined from a mathematical expression:
N QW / q + 1,
where N is the number of sections;
Q loading washing intensity, l / s • m ² ;
W loading surface area in terms of one section, m ² ;
q productivity of each section in the conditions of washing one section, l / s;
and culverts 3 should be located at a mark below the maximum allowable, but above the minimum allowable water level when flushing in the pipeline 9.

 The filter works as follows. The water to be purified is supplied through a pipe 8 to the first and last sections 4. Water first fills the first and last sections, then through the culverts 3 in the partitions 2 flows into adjacent sections, gradually filling all sections. At the same time, water is filtered downward through the filter charge 5, as a result of which the drainage and distribution cavity 7 is filled with a clean filtrate. The filtrate enters the discharge pipe 9; air is displaced from it through the plunger 10 and then it moves through the check valve 11 into the exhaust system.

 As a result of filtering the water in the filter load 5, deposits are formed that narrow its channels. The hydraulic resistance of the load 5 increases, the performance of the device drops to the predetermined value. At this point, it is necessary to start washing the filter load 5. To do this, open the shutter 15 on the mud pipe 12, for example, of the first section.

 If there are siphons instead of mud pipes 12, the water level in one of the siphons will rise to its top by the time the washing is necessary and it will be charged with water, the installation will automatically switch to washing washing mode 5. This was facilitated by the increased pressure in the installation above loading 5 due to clogging its channels sediments.

 The water level above the filter charge 5 in the rinsed section will decrease, the reverse filtrate current will appear in the load, loosening it and washing away deposits from it. The hydraulic resistance of the load 5 will decrease, as a result of which the pressure of the filtrate in the drainage and distribution cavity 7 will decrease and therefore the water level in the pipe 9 will decrease, the check valve 11 will close. During washing, the water level in the remaining sections decreases due to filtering it into the drainage and distribution cavity and partially due to the discharge of a small amount of water into the washed section through the culvert hole 3 of the partition 2. It is a small quantity, since the effective pressure of the water above this hole in the process washing at the very beginning of it sharply decreases, usually from 2.5 meters to several centimeters above the threshold of the hole. Moreover, it should be borne in mind that in the case of flushing of the outermost section under consideration, all nonwashable sections continue to receive source water from only one side, on the other hand, it freely flows from the inlet pipe to the section being washed and is discharged into the sewer along the mud pipe 12 dirty wash filtrate. In this case, the supply of source water from both sides is almost the same and maximum, as when filtering through sections that are not yet contaminated. But the supply of source water to all non-washable sections decreased by half. It would seem that the total productivity of these sections should decrease and turn out to be insufficient to provide a washed section with a frequent filtrate. However, the required flow rate of pure filtrate for washing one section of the remaining sections is formed simultaneously from the flow rate of water supplied to all other sections and part of the upper layer of water above the filter charge in these sections. It is advisable to have a height, partitions, so that the base of the wash water layer in the sections is below the culverts 3. This will reduce the lateral outflow of feed water through the hole 3 into the wash chamber at the beginning of the wash and completely eliminate it by the end of the wash.

 During the washing of the filter load 5 of any section, the quality of the filtrate in the drainage distribution system does not deteriorate, since when the shutter 15 is opened, the pressure drops first under the housing cover above the load 5 due to the outflow of water through hole 3 into the washable section and the water surface is torn off the cover , which leads to a decrease in the flow rate of the filtrate, and then, as the load expands under the influence of the filtrate flow from below and decreases its hydraulic resistance, as well as under the effect of a gradual decrease in the water level in of the washed section, the filtrate consumption increases, gradually reaching the value that occurred at the beginning of the washing. Of course, to ensure this, the height distance from the openings 3 to the minimum permissible water level in the flushed section should be close in magnitude to the pressure loss at loading 5 by the beginning of the flushing. This height is set based on hydraulic calculation.

 After the rinsing layer of water of the neighboring section has been used up, the rinsing will decay somewhat and its further continuation becomes impractical. Water levels in the washed section and pipeline 3 will drop to the minimum, the position of which, however, is above the mark of the expansion of the load. The shutter 15 is closed. If a siphon is used instead of the mud pipe 12, it will discharge and the shutter 15 does not make sense to close; the gates 15 can be used to set the necessary flushing costs during the commissioning of the water treatment device in a production environment. The filter load will return to its initial state, and the sections, including the washed one, will be filled with source water, and the filtering process will continue in all sections. The pressure of the water in the drainage and distribution cavity will increase and again a clean filter will flow through line 9 and the check valve 11 into the discharge system.

 Similarly, any intermediate section is washed. The only difference is that through the openings 3 of two adjacent partitions 2, which form the flushing section, continuously merges into the last source water, but with the same total flow rate as when flushing the end section, i.e. almost equal to half the total water supply to the water treatment device. Therefore, regardless of the number of the flushed chamber, the discharge of dirty water from it should be carried out at such a rate that the water level in it gradually drops to the minimum allowable mark, which is slightly higher than the mark of the expansion of the load. In this case, the completion of its washing will occur automatically if, instead of mud pipes 12, siphons with water inlets are used at the minimum allowable water level in the sections.

 If the filter load in the water treatment device is granular, for example, like quartz sand, then the deposited grains will penetrate deep into the pores of the gravel layer through the upper grating 16 of the flow chamber 6. However, the grains will settle not lower than the smallest gravel in the middle of its layer and therefore the grains of loading 5 Do not wake up in the drainage and distribution cavity, as required. When washing the granular filter load, its grains are washed upward from the pores of gravel without noticeable difficulties.

 For conditions of weak water pressure in the discharge system, which does not ensure the closing of the non-return valve 11 when washing the sections, the discharge pipe 9 is made in a vertical L-shape to exclude the outflow of pure filtrate into the discharge system.

 The proposed water treatment device maintains the quality of the filtrate in the drainage and distribution cavity during the washing period of one of the sections, since the water pressure above the filter load in the remaining sections is reduced due to the discharge of part of the initial water into the washed section and further into the sewer. The loss of source water per day with one washing of all sections will be 0.4%, which is insignificant. At the same time, this water reduces the concentration of all kinds of substances, leading to overgrowth of sewer pipes by insoluble deposits, to inlaid and siltation phenomena.

 The device is simple in design and reliable in operation, in it all partitions have the same shape, which simplifies manufacturing, and there is no need for periodic shutdown of the supply pipe, which increases the reliability of the installation in operation. The installation is efficient and therefore meets the criterion of "industrial applicability".

Claims (2)

1. A filter for water purification, comprising a housing divided by partitions with culverts at their upper ends into a series of sections arranged in series, a filter load placed in sections, flow chambers attached to the lower parts of the sections, a drainage distribution device, leading and discharge pipes and mud pipes equipped with gates, characterized in that the drainage distribution device is designed as a horizontal of the plane that communicates with the flow chambers, the outlet pipe is L-shaped and bent with a plunger and check valve, the culverts are located at a mark below the maximum allowable but higher than the minimum allowable water level when flushing in an L-shaped curved pipe, the inlet pipe is connected to the first and the last section, the mud pipes are equipped with risers with funnels at the ends located at a level above the mark of the expansion of the load when flushing, and the number of sections is determined from the mathematical expression
N QW / q + 1,
where N is the number of sections;
Q washing intensity, l / s.m ² ;
W is the surface area of the load of one section, m ² ;
q productivity of each section when washing one section, l / s.  2. The filter according to claim 1, characterized in that the flow chambers are equipped with two horizontal gratings, the space between which is made by a layer of gravel with decreasing grain size from the gratings to the middle of the layer.

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