RU1782175C - Filter slot cap with filtering bulk material - Google Patents

Abstract

SUMMARY OF THE INVENTION: A slotted cap consists of a packet of rings with a decreasing gap from the bottom up to the gap between the rings. 1 ill. (/ with

Description

The invention relates to filters with a powder filtering material and can be used to clarify liquids from suspensions in the chemical, radiochemical and other industries.

Filters are widely used in water treatment and industrial water purification processes, the filtering material of which are granular materials of various nature: quartz sand, graphite, stainless steel powders. The latter are used to clarify aggressive liquids (acids and alkalis). Drainage devices are used to hold the particulate material in the filters, the designs of which, depending on the purpose of the filters, are very diverse.

The sand filters used to prepare drinking water use perforated pipes to which layers of filtering materials are laid as drainage.

A drainage device is known, consisting of a series of elements, each of which is a square package of stainless plates 10 mm high, 50 mm long and 0.3-0.5 mm thick. On each plate there are spacing protrusions that form calibrated slots 0.3 mm in size. The plates in the bag are fixed by a proppant; the bags are staggered in the partition separating the filtrate collection chamber from the granular material.

The disadvantages of the drainage device can be attributed to the fact that the slots of the bags are directed strictly upwards and in this regard, the drainage board between the bags has stagnant zones that are not washed away in an ascending XI CD

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the current of the washing solution supplied for the regeneration of the filter load by the fluidization method

A drainage device is known which, by most coincidence, is taken as a prototype.

This drainage device comprises a perforated housing, a lid and rings, between which spaced zigzag spacers are laid. The cross section of the slots along the height of the device is the same and uniform.

The disadvantages of the prototype should include different speeds of the regenerating liquid along the height of the device. Namely, the velocity (flow rate) from the lower slot will be minimum, and from the upper slot the maximum. This is explained by a decrease in hydrostatic pressure from the solution column and the height of the granular material. This drawback leads to the formation of stagnant zones between drainage devices at the lower slots and to the accumulation of a layer of permanent sediment, which periodically after regeneration enters the filtrate. Great troubles take place during clarification of solutions containing radionuclides. Gamma-emitting nuclides, together with sediments, settle in the stagnant zones of the drainage device and in fact cannot be decontaminated in case of repair work.

The aim of the invention is to ensure complete removal of sediment from the filter by eliminating stagnant zones.

The goal is achieved in that the filter for clarifying liquids, comprising a housing with inlet and outlet pipes, the filtering load, has a drainage device with variable slots and is inversely proportional to the height of the device, with the bottom slit with a maximum cross section located at the level of the drainage board.

The drawing shows a drainage slotted cap with a variable cross-section of the cracks with part of the drainage board.

The slotted cap consists of a set

discs 1, clamped together with three bolts 2. To form slots of a certain size, calibrated washers 3 are laid between the discs on the bolts, moreover, in order to create slots of different variable cross-sections (the largest cross-sectional area is below, and

smallest cross-sectional area at the top), washers

made of different diameters - the smallest

diameter at the bottom, largest diameter at the top.

The principle of operation of the device.

In the filtration process, the filtrate passes freely outside the cap inward through the slots between the disks. At the same time, a certain size of the slots prevents (holds) the passage of bulk granular material. AT

During the regeneration process, the solution passes the cap from the inside out. Moreover, due to the larger cross-sectional area of the lower slit, the solution speeds will be greater in the lower part of the cap and less in the upper part.

Such a device (variable cross section, lower slit at the level of the drainage partition) ensures the completeness of precipitation unloading.

The introduction of the proposed slotted cap will eliminate the accumulation of sediment and radionuclides in its lower part, and thus increase the quality of the filtrate and reduce the time of decontamination before repair work or changing the filter load.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION A slotted filter cap with bulk filter material comprising a packet of rings with spacers, characterized in that, in order to prevent the formation of stagnant zones, the sizes of the gaps between the rings are made decreasing in the direction from bottom to top.