RU2737685C1 - Method of determining layer thickness of cartridge filter material - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to purification of drinking water and can be used in production of bottled water. Disclosed is a method of determining thickness of a layer of filter material of a cartridge, according to which concentration of an element of contaminant substance in liquid is measured to filter material, portion of liquid is passed through the filtration material, while passing each portion through the filter material, concentration of the contaminant substance in the liquid passing through the filter material is measured for subsequent calculation.EFFECT: technical result is creation of method for determining thickness of filter cartridge material layer required for most effective use of filter in process of liquid cleaning.1 cl, 2 tbl

Description

The invention relates to the field of liquid purification, in particular, to the field of drinking water purification and can be used in the production of bottled water.

A known cassette filter contains a housing with cassettes installed in parallel to each other with the possibility of vertical reciprocating movement, in the lower part of which there are filter elements made in the form of flexible nets, interconnected by elastic bonds with an elastic porous filter material placed between the nets, and in the upper part there are impenetrable vertical partitions. In the intervals between the cassettes, squeeze rolls are located, while the squeeze rolls are made in the form of perforated cylinders coaxially located one in the other, communicated with the pipeline for draining the wash water, the outer of which is perforated and installed with the possibility of rotation, and the inner one is installed with the possibility of limited rotation. The filter is also equipped with pipelines for the supply of purified water, removal of filtrate and waste water and sediment, while the elastic porous filter material in the cassettes first in the direction of movement of the processed liquid is made of separate pieces with dimensions within (1.2-1.4) h, where h is the size of the mesh cells diagonally, along the perimeter in the frame of the cassettes an impermeable diaphragm is installed that partially overlaps the filter element of the cassette to a depth of 0.2 m, where m is the thickness of the filter element, which ensures uniform filtration of the liquid over the entire area of this element (RU 2174962 C1 , 20.10.2001).

Known is a continuous ring filter located in a radial sump, including a housing with inlet and outlet pipes, a sludge removal unit, while the floating loading of the ring filter has a granule size of 2-5 mm and a filter layer thickness of up to 0.5 m (RU 2066227 C1, 10.09.1996).

Known is a filter element made of sintered particles of synthetic materials, which generally has the shape of a narrow hollow box with two large, zigzag or wavy, first side walls, two narrow, second side walls that connect the first side walls to each other, with a closed side forming the bottom and the opposite open side, wherein the projections and recesses of the first side walls extend in the direction from the side forming the bottom to the open side, and further on the open side of the filter element there is provided a head for fastening, which is elongated and forms at least least, the site for the passage of the stream. The filter element has two halves connected to each other, which respectively contain one of the first side walls, the head part and the base are molded from synthetic resin, the head part being molded to the first and second side walls in such a way that it covers the first part of its height outside the first and second side walls and with the second part of its height protrudes beyond the first and second side walls and overlaps them at their ends, the head part in the second part of its height at at least one section of the flow creates a transition favorable for flow from a limited zigzag or wavy spaces between the two first side walls in a generally rectangular cross-section of the flow (RU 2173205 C2, 10.09.2001).

A device for filtering liquids is known, comprising a housing having an inlet for the liquid to be purified and a filtrate outlet, a partition with openings in its upper part and filter elements. The body is made in the form of a rigid frame made of several vertically placed U-shaped flat steel hinges, installed symmetrically relative to the axis of the device on a partition disk in the upper part, elongated along the length of the device and fastened together by several rings of larger and smaller diameters, fixed in the horizontal planes at several levels along the height of the device and passing inside and outside each U-shaped loop, the filtering elements of the device are a one-piece cover, put on a rigid frame and fixed in the upper part of the device under the partition disk and in the middle (in height) part from displacement ... In this case, the cover contains the outer and inner sorption-filtering layers of materials, and the thickness of the material of the inner sorption-filtering layer is related to the thickness of the outer sorption-filtering layer, as 1:13 (RU 2400285 C2, 09/27/2010).

The main disadvantage of these inventions is the lack of a preliminary calculation of the thickness of the filter layer, which is necessary for the most efficient operation of the filter.

The problem to be solved by the present invention is to develop a method for calculating the layer thickness of the filter material of the cartridge.

The technical result achieved when solving the problem is to create a method for calculating the layer thickness of the filtering material of the cartridge necessary for the most effective use of the filter in the process of liquid purification.

To achieve this technical result, a method is proposed for determining the thickness of the layer of the filtering material of the cartridge, according to which the concentration of the pollutant substance element in the liquid is measured before the filtering material, the liquid is passed through the filtering material in portions; through the filter material, for subsequent determination of the ratio of the concentration of the element of the pollutant substance before the filter material to its concentration after the filter material according to the formula:

α _{i, j, k, p} = C _{i, j, k, 0} / C _{i, j, k, p} where

α _{i, j, k, p} - filtration coefficient for the case of a portion p;

i is the number of the pollutant substance;

j is the number of the filter element;

к - number of the investigated thickness of the filtering element;

p - portion number;

C _{i, j, k, 0} - concentration of the pollutant substance i before passing through the filter element j of a given thickness k;

C _{i, j, k, p} is the concentration of the pollutant substance i after passing a portion p through the filter element j of a given thickness k,

on the basis of the data obtained, bilinear interpolation is performed using the Langrange interpolation polynomial, forming a set of functional dependencies for the filtration coefficients for each element of the pollutant in the liquid and the filter material, depending on the thickness of the filter material and the volume of the liquid passed through it, then, based on the SanPin standards, the permissible the values of the concentrations of the pollutant substance element in the liquid [Ci], as well as the maximum initial concentrations of the pollutant substance element [Ci ^max ], on the basis of which the value of the filtration coefficients is calculated by the formula:

α _i = Ci / Ci ^max ,

after which, by numerical methods, the thickness of the layer of the filtering material of the cartridge is determined for each element of the pollutant substance.

The method for determining the layer thickness of the filtering material of the cartridge, which is intended for the purification process, for example, bottled drinking water, is carried out as follows.

In laboratory conditions, the concentration of the pollutant substance element (i) is measured before the filter element (j). Then, through the filter element (j) of thickness h _j , _k , where k is the number of the investigated thickness, pass a volume of liquid equal, for example, 350 liters in portions, for example, 10 liters. The total volume of the liquid passed through the filter element is determined based on the required resource of the filter element (300 l), which, like the volume of the filter bottle, is determined based on the market demand. After passing each portion through the filter element (j), the concentration of the pollutant substance element (i) is measured and the ratio of the concentration before the filter to the concentration after the filter is determined.

α _{i, j, k, p} - filtration coefficient for the case to portion p;

i is the number of the pollutant substance;

j is the number of the filter element;

к - number of the investigated thickness of the filtering element;

p - portion number;

C _{i, j, k, 0} - concentration of the pollutant substance i before passing through the filter element j of a given thickness k;

C _{i, j, k, p} is the concentration of the pollutant substance i after passing a portion p through the filter element j of a given thickness k,

At the same time, in order to reduce the number of search iterations k, for each filter element, 6 successive values with a thickness from 0.5 mm to 5 mm are selected according to table. one.

Further, for each pollutant substance (i) and filter element (j), a table (Table 2) of filtration coefficient values is formed.

Further, bilinear interpolation is performed using the Lagrange interpolation polynomial, according to the dependence:

Where

a _{i, j} (h, o) - filtration coefficient as a function of two variables;

h is the thickness of the investigated filter element;

o - filtering capacity of the studied filtration element;

ƒ _pk is the value of the filtration coefficient at the node [h _p, o _k ];

p is the number of the interpolation step according to the thickness values of the investigated filter element;

k - step number of interpolation by the thickness of the filter element;

h _i - the value of the thickness of the filter element at the i-th step of interpolation;

o _i - the value of the filtering ability at the j-th step of interpolation;

i is the number of the summation step by the values of the thicknesses of the filter element;

j is the number of the summation step by the values of the filtering capacity of the filter element.

Thus, a set of functional dependencies is formed for the filtration coefficients for each pollutant substance (i) and filter element (j), depending on the thickness of the filter element (j) and the volume of liquid passed through it.

After that, you need to check with the SanPin standards, select the permissible values of the concentrations of pollutants (C _i ). And based on the scope of the filter and the use of the worst-case principle, the maximum initial concentrations of pollutants (C _i ^max ) are selected. Then the required values of the filtration coefficients are calculated according to the dependence:

Further, based on conditions (3), numerical methods are used to select the required value (h _{i, j} ) for each of the pollutant substances.

As a result, among the found set of values, the thicknesses of the filter elements are selected: h _j = max (h _{i, j} ).

The proposed method for determining the thickness of the layer of the filtering material of the cartridge allows you to accurately determine the required thickness of the layer of the filtering material of the cartridge. At the same time, for a specialist it is obvious that this method can be used in various industries and the proposed calculation using the example of the production of bottled drinking water is only a special case of implementation.

Claims (12)

A method for determining the thickness of a layer of a filtering material of a cartridge, characterized in that the concentration of an element of a pollutant substance in a liquid (i) is measured up to a filtering material (j), a portion of the liquid is passed through the filtering material (j), while each portion passes through the filtering material (j) the concentration of an element of a pollutant substance in a liquid that has passed through the filter material, for subsequent determination of the ratio of the concentration of an element of a pollutant substance before the filter material to its concentration after the filter material according to the formula:

where

- filtration coefficient for the case to portion p; i is the number of the pollutant substance; j is the number of the filter element; к - number of the investigated thickness of the filtering element; p - portion number; C _{i, j, k, 0} - concentration of the pollutant substance i before passing through the filter element j of a given thickness k; C _{i, j, k, p} is the concentration of the pollutant substance i after passing a portion p through the filter element j of a given thickness k, on the basis of the obtained data, bilinear interpolation is performed using the Lagrange interpolation polynomial, forming a set of functional dependencies for the filtration coefficients for each element of the pollutant in the liquid and the filter material, depending on the thickness of the filter material and the volume of the liquid passed through it, then, based on the SanPin standards, the permissible the values of the concentrations of the pollutant substance element in the liquid [Ci], as well as the maximum initial concentrations of the pollutant substance element [C _i ^max ], on the basis of which the value of the filtration coefficients is calculated by the formula: α _i = Ci / Ci ^max , after which, by numerical methods, the thickness of the layer of the filtering material of the cartridge is determined for each element of the pollutant substance.