RU2326716C2 - Filter element for liquid and gaseous media - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: filter element for filter-separators is intended for clearing liquid and gaseous media of impurities and free moisture in the form of aerosols and may be used in petroleum refining and aircraft industries as well as in other industrial branches. The above filter incorporates a filtration and coagulation layers arranged streamwise the media being filtered and is made from thermoplastic polymer fibres, primarily from polypropylene. Note that coagulating layers are made from fine fibres and separated by a layer of coarse fibres, the density of coagulating layers on the side of the incoming medium to be filtered exceeding that on the outlet side.

EFFECT: simpler and cheaper filter design.

1 ex, 1 tbl, 2 cl

Description

The present invention relates to the production of multilayer fibrous filter elements, to filter separators for cleaning gaseous and liquid media from mechanical impurities, free moisture and aerosols, mainly natural gas and oil products, and can find application in gas transmission systems, oil refining, aviation and other industries industry.

Known filter elements made multilayer (application Germany No. 2600228, class B01D 27/06, international application WO 2004/014517, class B01D 29/50, German patent No. DE 69331102 T2, class B01D 29/11, German patent No. DE 69723714 T2, CL B01D 17/04, patent RU 22567484, CL B01D 39/16).

The filter elements described in these patents, differing in their design features, contain, as a rule, three obligatory layers: a filtering layer to retain mechanical impurities, a coalescent or coagulating layer, and a drainage or water-repellent layer.

Known multilayer filter element for filter separators, protected by the patent of the Russian Federation No. 2228785, class. B01D 27/00, B01D 17/02, publ. 2004.07.11, intended for use in gas transmission systems, in the oil refining, aviation and other industries for cleaning the filtered medium from mechanical impurities and free water.

The filter element contains filtering, first and second coagulating layers, a layer for enlarging free water in the form of a cotton tube and a water-repellent layer arranged along the flow of the medium to be cleaned.

The filter layer is made of two layers of paper with a decrease in pore size in the flow of fuel. The first coagulating layer is made in the form of a mat of fiberglass and compressed by a fiberglass mesh. The second coagulating layer is made of needle-punched material.

The disadvantage of the described filter element is its extremely complex design and the use of various materials in its manufacture, which leads to an increase in the cost of the filter separator as a whole. In addition, the use of paper with a low mechanical strength for the manufacture of a filter layer of paper can lead to loss of strength and destruction of the filter layer when filtering a medium with a high content of free water.

In technical essence, the closest to the present invention is a multilayer fibrous filter element made of fibers of a thermoplastic polymer, including polypropylene, described in patent RU 2182509.

The filter element consists of alternating between thin-fibrous and thick-fiber layers. The thin fiber layers are made of fibers with a diameter of 5-10 microns, and the thick fiber layers are made of fibers with a diameter of 10-30 microns. The thickness of the thick fiber layer can be 12-254 microns, and the thickness of the fine fiber layer is 10-30 microns. The filter medium is the thin fiber layers, and the thick fiber layers serve as a spacer between the thin fiber layers.

The filter element is sheet-wise. A folded structure may be formed from the sheet or the sheet may be “rolled up” into the pipe and installed in the filter in this form.

The disadvantages of the filter element of the prototype are,

firstly, its limited use is the removal of solid particles from the air stream supplied to the cabs of vehicles, to the equipment of power plants or from gas streams sent to gas turbines, i.e. we are talking about air filters and a relatively clean filtered medium. Such filter elements are not suitable for filtering heavily contaminated liquid and gaseous media with a high content of solids and free moisture, such as natural gas;

secondly, these filters are relatively expensive, due to the multi-stage technology of their manufacture. The technology includes the formation of a lining layer of thick fibers and the deposition of thin fibers on it.

The objective of the invention is the creation of an inexpensive multilayer filter element of the filter separator, which provides a high degree of purification of gaseous and liquid media, such as natural gas and liquid fuel, both from mechanical impurities and from free moisture contained in the filtered medium in the form of aerosols.

The problem is solved due to the fact that the known multilayer filter element for liquid and gaseous media, made of fibers of a thermoplastic polymer, mainly polypropylene, and consisting of alternating thick-fiber and thin-fiber layers, is made by extrusion in the form of a hollow cylinder with a thick-fiber outer layer, and the thick fiber layers are composed of fibers with a diameter of 100-150 microns, and the thin fiber layers are made of fibers with a diameter of 1-5 microns.

In contrast to the prototype, the present invention allows to create a cost-effective efficient filter element due to

- performing a filter element in the form of a hollow cylinder by extrusion (in the prototype, a tubular filter element is obtained by folding a prefabricated multilayer sheet of complex structure);

- execution of the layer from the input side of the filtered medium with a thick fiber, taking on coarse mechanical impurities (in the prototype, the role of the filter layers is played by the thin fiber layers, and the thick fiber layers serve as a spacer between them. Their main purpose, as follows from the description, is to serve as a lining for the thin fiber layer when its formation);

- alternating layers of the same density of fiber with a diameter of 100-150 microns with layers whose density decreases along the direction of the filtered medium, and which are made of fiber with a diameter of 1-5 microns.

The essence of the invention is illustrated by the following example.

Example.

From the fibers of polypropylene by extrusion, a filter element was formed in the form of a hollow cylinder, consisting of seven layers. The characteristics of the layers are given in the table.

When passing through the first thick-fiber layer made of fiber with a diameter of 100-150 microns, having a density of 0.20 g / cc and a thickness that is 20% of the thickness of the filter element, the filtered medium / natural gas or liquid fuel is freed from coarse mechanical impurities . In the next, thin-fiber layer, whose density is 0.40 g / cc and the fiber diameter is 1-5 microns, a finer cleaning process takes place, as well as the enlargement of water droplets contained in the filtered medium in the form of aerosols and the formation of water films. When the filtered medium exits from the thin-fiber layer to the thick-fiber layer, the laminar process becomes turbulent, which is accompanied by a significant loss of kinetic energy, especially by heavier fractions of the filtered medium (water and impurities contained in it). In this case, under the action of gravitational forces, partial draining of heavy fractions to the lower part of the filter element occurs and about 70% of the droplet water is removed from the filtered medium.

This is facilitated by the change of the turbulent process to a laminar process when the filtered medium enters the denser fine-fiber layer with a density of 030 g / cc (fourth in the direction of travel). Drops of water, which did not have time to reach the bottom of the filter element, partially fall into this layer.

Each time the filtered medium passes from a thin-fiber layer to a thick-fiber layer (from a denser to a less dense layer), the laminar process goes into a turbulent one and coarsening of water droplets and removal of water from the filtered medium. The density of the thin fiber layers decreases along the direction of the filtered medium, while the density of the thick fiber layers remains constant.

The proposed design provides almost complete removal of mechanical impurities and allows you to clean natural gas or liquid oil from drop water by 97-98%.

Table Layer thickness in% Layer density g / cc Micron fiber diameter twenty 0.20 100-150 fifteen 0.40 1-5 7.5 0.20 100-150 fifteen 0.30 1-5 7.5 0.20 100-150 fifteen 0.25 1-5 twenty 0.20 100-150

The multilayer fibrous structure of the proposed filter element provides effective cleaning of liquid and gas media from mechanical impurities and free water present in the filtered medium in the form of aerosols. The use of fibers from a thermoplastic polymer, mainly from polymer, gives the filter element high chemical resistance to a wide range of chemicals.

Compared with the prototype, the proposed filter element has a low cost, is easily mounted and dismantled.

Claims (2)

1. A filter element for liquid and gaseous media containing alternating filtering coarse-fiber and coagulating fine-fiber layers placed on the flow of the filtered medium made of thermoplastic polymer fibers, characterized in that the tubular-type filter element is made by extrusion, the outer filter layers consist of fibers with a diameter of 100 -150 microns, and coagulating layers of fibers with a diameter of 1-5 microns, while the density of the coagulating layers on the inlet side of the filtered medium is greater than on the side exit. 2. The filter element according to claim 1, characterized in that it is made of polypropylene fibers.