RU1792339C - Filtration material for trapping fume mainly of ammonium salts - Google Patents

Abstract

Usage: capture fumes of ammonium salts. SUMMARY OF THE INVENTION: the filter material contains frontal and trailing fibrous layers of coarse synthetic fibers, and an intermediate layer of thin fibers located between them, the latter made of viscose fibers, the content of which is May 25-33. % of the total mass of fibrous material. 1 tab.

Description

The invention relates to the field of production of non-woven filter materials intended for trapping aerosols, in particular ammonium smoke fumes .. / g:

Known filter media for collecting fogs. This material consists of three layers, finer synthetic fibers being used for the inner layer with a porosity of 91-94%, and the frontal and closing layers contain coarse synthetic fibers and have a higher porosity (94-97%). The filter material is made by needle-punched method. The described material in its technical essence and the achieved positive effect is closest to the proposed and taken as a prototype.

The fumes of ammonium salts are aerosols containing particles of pollution with sizes of 0.5-1.5 microns. The cleaning efficiency should be at least 95%. Known material has

low capture efficiency in particle ratios of less than 1 micron. This is explained by its high air permeability (1000 dm3 / m2s according to GOST 12088-77), which indicates that. that the material has a rather loose structure.

The purpose of the invention is to increase the retention capacity of the filter material with respect to particles of less than 1 micron.

The essence of the invention lies in the fact that in a non-woven filter material containing a frontal and trailing fibrous layers of coarse synthetic fibers, and an intermediate layer of thin fibers located between them, the latter is made of viscose fibers, the content of which is 25-33 weight percent of the total mass fibrous material.

Ammonium salt smoke particles are trapped in the fibers of the windshield of the core. Upon contact with the surface of the fibers, the particles form liquid films

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As the thickness increases, the film becomes unstable and breaks up into individual droplets, which roll along the fibers at the bending points of the cohesion of the fibers of the intermediate layer.

Due to the fact that the intermediate layer is made of thin viscose fibers, dblad1-d1 SpenKy, all synthetic with hydrophilicity, they swell with an increase in fiber diameter, which leads to a decrease in pore size and porosity in general, which in turn, provides an increase in the retarding ability and fineness of the filtration .; .-.

Under the action of capillary forces, the intermediate layer is filled with liquid. Excess fluid from the material structure is discharged through the closing layer c; in the form of drops. The structure of the closure layer contains pores of larger sizes in comparison with the pores of the intermediate layer; therefore, excess liquid is easily removed from the intermediate layer, i.e. self-regeneration of the filter material is carried out. The invention is illustrated by the following examples. Examples 1–3 characterize food grade material, examples 4 and 5 are control. :: ...:

Example 1. An intermediate fiber layer mechanically formed from viscose fibers with a linear density of 0.31 tex is laid on a closing fibrous layer mechanically formed from synthetic fibers with a linear density of 2 tex, a cutting length of 65-70 mm, and a surface density of 210 g / m2 , cutting length 65-70 mm, surface density 210 g / m2. Then, a frontal fiber layer identical to the closure is applied to the i-formed fibrous xoflcfbi. The formed canvases are bonded together by needle-piercing from the frontal layer with a puncture density of 120, a puncture depth of 10 mm, and then with ctopQHbf, with a puncture density of 120 cm and a depth of 7 mm. The capture efficiency of the material is 98.7%. ..

PRI me R 2. The material according to example 2 is made the same way as in example 1, but the intermediate layer has a surface density of 180 g / m2. The collection efficiency of the material is 97.6%.

Example 3. The material of Example 3 is manufactured in the same manner as in Example 1, but the surface density of the intermediate layer is 150 g / m2. The capture efficiency of the material is 97.0%.

Example 4. The material of Example 4 is manufactured in the same manner as in Example 1, with the exception of the intermediate layer, whose surface density is 250 g / m2. The capture efficiency of such material is 93.6%,

Example 5. The material of example 5 is made in the same manner as in example 1, with the exception of the intermediate layer, the surface density of which is 130 g / m2. The capture efficiency of the material is 95.3%,

. The proposed material, control samples and prototype material were tested on an ideal aerosol - glycerin with a particle size of 0.5-1.0 μm.

The data in the table indicate that if the content of viscose fibers in the intermediate layer is exceeded, a decrease in cleaning efficiency is observed. This is explained by the fact that a large amount of liquid accumulates in the intermediate layer, which, under the influence of gravity, extends the intermediate layer with the formation of large pores and structural damage. A decrease in the content of viscose fibers in the intermediate layer also reduces the cleaning efficiency for due to the fact that the amount of viscose fibers is not sufficient for the accumulation of moisture, which is able to neutralize aerosols of ammonium srleyt

Compared with the prototype, the proposed material has a 7-8% higher retention capacity.

Claims (1)

SUMMARY OF THE INVENTION Filter material for capturing fumes, mainly ammonium salts, containing a frontal and trailing fibrous layers of coarse synthetic fibers and an intermediate layer of fine fibers, interconnected by needle-piercing, between them and so that , in order to increase the efficiency of capture, the intermediate fibrous layer is made of viscose fibers, and their content is May. % of the total mass of fibrous material.