RU2458727C1 - Filtration element - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention is intended for removing mechanical impurities and water from hydrocarbon fluids. Filtration element comprises rigid permeable cylindrical carcass, for example, made up of helical wrap spring from elastic material. Said carcass supports pack of filtration sections from elastic porous material. Said pack is made up of filtration sections with trapezoidal cross-section, squeezes in crosswise direction and glued together by their side faces. Degree of squeezing increased from OD to ID to comply with required fineness of filtration. Covers are glued to filtration section end surfaces. Pack ID and OD are selected subject to required fineness of filtration.

EFFECT: increased dirt capacity, longer life, simplified design.

2 cl, 2 dwg, 1 ex

Description

The invention is intended for the purification of hydrocarbon liquids from mechanical impurities and water and can be used in the chemical, oil refining, automotive and other industries.

Known filter element of the volume type, consisting of a perforated tubular frame, covers and filter packing, which is a set of disks from a deformable porous filter material and conical gaskets (AS No. 1153947). Gaskets are arranged in pairs with the tops of the cones towards each other. The filter disks are crimped by gaskets, as a result, the disks are deformed, providing porosity changing in the direction of the filtered fluid flow. Disks compressed by gaskets on the side of the base of the cones have a minimum porosity at the inlet, which creates higher hydraulic resistance at the entrance than disks compressed from the side of the tops of the cones. For this reason, the main fluid flow passes through the disks compressed from the tops of the cones, and the porosity in these disks decreases in the direction of the filtered fluid flow, which provides a selective retention of contaminants inside the volume of these disks. The minimum porosity at the entrance to the disks, compressed from the base of the cones, is also the reason for the localization of contaminants on their outer surface, which additionally prevents the passage of fluid through these disks. Thus, that part of the volume of filter material that falls on the disks, compressed from the base of the cones, is not involved in the process of delaying pollution, as a result, the dirt capacity and resource of the filter element are reduced.

Also known is a filter element designed for the purification of hydrocarbon liquids (AS No. 1804887, prototype), consisting of a perforated tubular frame, covers and filter packing from disks of larger and smaller diameters, made of a deformable porous material, alternately assembled and crimped in axial ( longitudinal) direction to the mutual contact of large disks. The disadvantage is that this design, in fact, is a two-stage, which does not provide a gradual clogging of pores along the cross section of the filter element, i.e. the entire volume of the filter material is not used, which leads to a decrease in the dirt capacity and resource of the filter element. The perforated tube frame has an increased hydraulic resistance and increases the cost of the filter element.

The task of the invention is to increase the dirt capacity of the filter element, increase the resource of its work and simplify the design.

The technical result that allows us to solve the problem is to gradually clog the pores of the filter sections due to their uniform reduction obtained as a result of compression in the transverse direction, and, as a result, an increase in the duration of the process for cleaning hydrocarbon liquids.

The technical result aimed at solving the problem is achieved as follows.

The filter element claimed as an invention has in common with the prototype that it contains a rigid permeable cylindrical frame, a package of filtering compressed sections of elastic porous material located on the frame, the compression ratio of which increases from the outer diameter to the inner one and is made in accordance with the required filtering fineness, and end caps.

Unlike the prototype, the bag in the inventive filter element is assembled from longitudinal filter sections having a trapezoidal shape in cross section, compressed in the transverse direction and glued together by side faces, while the outer and inner diameters of the bag of compressed filter sections are determined by the formula:

where d _n is the outer diameter of the bag of filter sections;

d _in - the inner diameter of the package of filter sections;

x _max - maximum particle size of contaminants;

d _0,95 - the required nominal filter fineness;

m is an empirical measure of the degree of elastic porous material to provide the required degree of compression.

The permeable cylindrical frame can be made in the form of a cylindrical coil spring from an elastic material.

The choice of the main structural parameters (d _n , d _c ) of the proposed filter element and the degree of compression of the filter sections depend on the required nominal filter fineness.

For deformable porous materials, the required degree of compression of the elastic porous material, which ensures the retention of particles of a certain size, is determined by empirical formulas of the form:

where d _0,95 - the required nominal filter fineness;

n is the required degree of compression of the elastic porous material;

k is the empirical coefficient of the elastic porous material to ensure the required degree of compression;

m is an empirical measure of the degree of elastic porous material to provide the required degree of compression.

For example, for deformable porous polyurethane foam PPU-EO-130k = 79.43 and m = 1.466 (A.S. No. 1804887).

According to formula (1), the required degree of compression of the material outside (at the entrance) - n _n and inside (at the exit) - n _in will be:

The greater the degree of compression, the smaller the diameter of the filter element, therefore, the following follows from this:

where d _n is the outer diameter of the bag of filter sections;

d _in - the inner diameter of the package of filter sections;

x _max - maximum particle size of contaminants;

d _0,95 - the required nominal filter fineness;

m is an empirical measure of the degree of elastic porous material to provide the required degree of compression.

Thus, using formulas (2) and (4) to determine the design parameters of the proposed filter element, it is possible to ensure its operation with a maximum resource.

The set of essential features that characterizes the claimed invention in known sources of information is not found. This confirms the novelty of the invention.

In the prior art, filter elements made of compressed longitudinal trapezoidal sections have not been identified, and the design parameters of the filter element would be determined from the ratio

Despite the simplicity of the technical solution, the invention does not explicitly follow from the prior art, which means that it meets the criterion of "inventive step".

The spring in the inventive filter element acts as a rigid permeable cylindrical frame, which, due to its elasticity, prevents the trapezoidal filter sections from displacing under the pressure of the liquid.

Further, the invention is illustrated by drawings, which depict the inventive filter element and structural elements.

Figure 1 shows a General view of the filter element, figure 2 is a cross section of the filter element.

The volumetric type-setting filter element contains a rigid permeable cylindrical frame around which trapezoidal filter sections 1 are packed into a bag and glued together by lateral sides, forming a cylindrical hollow packet of filter sections, inside which a coil spring is installed 2. Covers 3 and 4 are glued to the end surfaces of the filter sections 1 The drawings also noted: H - the height of the filter element; d _n - the outer diameter of the bag of filter sections; d _in - the inner diameter of the bag of filter sections.

First, the parameters of the filter element are determined.

Example of filter element calculation

It is required to manufacture a filter element that provides a nominal filter fineness of d _0.95 = 25 μm and having an outer diameter of d _n = 100 mm. The filtering element is recruited from compressed trapezoidal sections in an amount of 12 pcs. Made of PPU-EO-130. For the deformable porous polyurethane foam PPU-EO-130, the empirical coefficient is k = 79.43 and the exponent is m = 1.466 (a.s. No. 1804887). An oil contaminated with mechanical impurities with a maximum particle size x _max = 50 μm enters the filter element.

By the formula (4) we find the inner diameter of the filter element d _in :

The inner diameter of the filter element to ensure a given nominal filtration fineness d _in = 62.5 mm

By the formula (2) we find the degree of compression of the outer surface of the porous material for subsequent compression sections:

For another porous filter material, the coefficient k and the exponent m are also determined empirically, for example, by the method described in [Kadochnikova M.V. Improvement of oil filter elements of chemical technology machines and development of methods for their calculation: Dis. Cand. those. sciences. - Tomsk, 1989. - 182 p.].

The filter element is made as follows.

1. Of the deformable porous material (polyurethane foam) are made compressed trapezoidal sections, the length of which corresponds to the height of the filter element, in an amount corresponding to the accepted number of trapezoidal sections 1 (1, 2). The compressed section should have pores on the outside corresponding to the particle size of the impurity x _max = 50 μm. Inside the section is compressed 1.371 times more. This can be ensured during the assembly process up to d _in = 62.5 mm.

2. On the side faces of the trapezoidal sections, glue is applied and collected on a cylindrical mandrel, the diameter of which is equal to the inner diameter of the filter element.

3. After gluing the sections along the side faces, a cylindrical mandrel is removed and a coil spring is inserted into the obtained hollow porous cylinder.

4. Covers 3 and 4 are glued to the end surfaces of the filter sections 1.

Claims (2)

1. A filter element containing a rigid permeable cylindrical frame, a packet of filtering compressed sections of elastic porous material located on the frame, the compression ratio of which increases from the outer diameter to the inner one and is made in accordance with the required filtering fineness, and end caps, characterized in that the packet assembled from longitudinal filter sections having a trapezoidal shape in cross section, compressed in the transverse direction and glued together by side faces, while the outer and the inner diameters of the bag of compressed filter sections are determined by the formula:

where d _n is the outer diameter of the bag of filter sections;
d _in - the inner diameter of the package of filter sections;
x _max - maximum particle size of contaminants;
d _0,95 - the required nominal filter fineness;
m is an empirical measure of the degree of elastic porous material to provide the required degree of compression. 2. The filter element according to claim 1, characterized in that the permeable cylindrical frame is made in the form of a cylindrical twisted spring of elastic material.

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