SU997731A1 - Method of cleaning liquid and versions of apparatus for performing same - Google Patents

Description

(54) METHOD FOR CLEANING LIQUIDS AND DEVICES FOR ITS IMPLEMENTATION

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The invention relates to filter technology and can be used to clean viscous liquids, such as oil, fuel oil, gas turbine fuel, from coarsely dispersed impurities.

A known method of purification of liquids from dispersed impurities by the flow of the purified stream through the slit filter channels of the filter septum} -

Known slotted filter containing the casing with nozzles for supplying and discharging the liquid, the filter chamber with filter elements mounted on the casing and made in the form of plates forming the slotted filter channels and the shaft 2.

Known technical solutions do not provide selective filtering of only coarsely dispersed impurities; therefore, slotted filter channels are overgrown with highly dispersed solid, ointment and gas particles, although their retention is not provided for by the technological process. As a result of this, the operational capabilities of the filter are limited.

The purpose of the invention is to expand the operational capabilities of the slit filter by preventing the overgrowth of the slit filter channels with highly dispersed impurities.

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The goal is achieved by the fact that, according to the method of cleaning liquids from dispersed impurities, a clean pressure gradient dp / dx, the average value of which is determined from

ratio Р „-1.

VP J s-Ti- (t

where P is the pressure of the fluid in the slit filter channel. Pa;

X is the current longitudinal-axial coordinate, m;

P, is the pressure of the fluid at the entrance to the slot channel (at the point with coordinate Xa, m), Ca;

G - pressure of fluid at the exit of the slotted channel, (at the point with coordinate Xg, m), ha.

The method is implemented by a device, which is a slit filter, containing a casing with nozzles for supplying and discharging liquid, a filter chamber with filtering elements mounted on the casing and made in the form of plates forming slit filter channels, the filtering chamber is placed between the casing and the filtering element and made with a decreasing volume in the course of the fluid being cleaned.

It is advisable to install the casing eccentric to the axis of the filter elements.

According to the second variant, in the slit filter for cleaning fluid containing a movable belt and shells installed with a gap to it, forming slotted channels with the tape, the shells are equipped with plates installed along the belt and forming filter slots between them, while the shells are made decreasing in height tape movement.

Example 1. Filtration of turbine oil brand TKP-22. Composition of impurities: 4 vol.% Silica gel crumb (contaminant) with particle sizes from 150-300 microns and 1.5 vol.% / O dispersed teflon (micropolar additive) with particle sizes from 50 to 10 microns. Oil heated to 50 ° C (dynamic viscosity 0.02 P) with an overpressure of 0.3-10 Pa is supplied to a slit filter installed in the wedge gap of a fractional-viscous hydrodynamic supercharger (Fig. 1). The gap between adjacent plates of the filter is 0.19 mm, the coefficient of the living section of the filter is 0.49. A shaft neck with a diameter of 0.1 m is driven into rotation with a circumference speed of 1.95 m / s. As a result of the hydrodynamic feed of the shaft along the slit filter channels, a positive pressure gradient of 0.37 MPa / m is created. The initial specific (referred to 1 area of the living section) clean filter capacity qi 1.3 m3 / (m2 s) after 25 hours decreases by the control value and reaches the value q2 0.02 (m2 s).

The composition of impurities in the filtered oil: 0.5 vol. ° / about silica gel crumb and 1.4ob ° / about teflon. Inspection of the filter confirmed the high selectivity of filtration of silica gel and insignificant overgrowing of the gaps with Teflon.

To obtain comparative data, conventional filtering of the same type of oil is carried out in a similar filter (but with a non-rotating shaft journal). The initial qi value of 1.3 (m s) for a clean filter is reduced by 98% after 16 hours. The composition of the impurities in the filtered oil: 0.5 vol.% Silica gel crosslink and 0.2 06.% teflon. Inspection showed intensive overgrowing of the filter slots with Teflon particles. Thus, the proposed method of oil purification allows, by delaying large harmful mechanical impurities (silica gel), to skip useful additive particles (Teflon), at the same time to increase the service life

filter before the next cleaning.

Example 2. Filtered mazut grade M-40. Composition of impurities: 5% by volume of asphalt-resinous particles with a particle size of from 20 to 100 microns and 0.15% vol. / O solid mechanical impurities ranging in size from 150 to 250 microns. Fuel oil heated to 80 ° C (dynamic viscosity 0.016 P) with an overpressure of 0.3 10 Pa is supplied to the slit filter described in Example 1. The shaft journal is rotated at a peripheral speed

2.6 m / s. A positive pressure gradient of 3.9 x X 10 Pa / m is created along the slit channels. The initial specific throughput of a clean filter qi 1, / () after 19 h is reduced by 98%. The composition of impurities in the filtered oil:

4.7% / o of asphalt-resin particles and 0.05% by volume of mechanical impurities. Inspection showed a slight overgrowing of the filter gaps with resins and asphaltenes.

With the usual filtering of the same type

5 fuel oil on a similar slit filter (but with a non-rotating shaft), the initial value qi 1.73 (m2 s) for a clean filter is reduced by 98% after 7 hours of continuous operation of the installation. The composition of impurities in the filtered fuel oil: 2.9 06.% ac0 filter-resin particles and 0.05% vol. Solids. Thus, the proposed method of cleaning fuel oil allows, by delaying large, solid, harmful mechanical impurities, to skip for

, subsequent disposal (incineration) of fine particles of resins and asphaltenes, while simultaneously increasing the service life of the filter.

Example 3. Filtration of diesel fuel brand DT. The composition of impurities: 0.15% by volume of solid mechanical particles with a particle size of 50 to 300 microns and 1.5% by volume of dispersed air in the form of bubbles with a diameter of 0.1 to 1 mm (at atmospheric pressure). Fuel heated to 50 ° C (di-namic viscosity of 0.08 P) with an overpressure of 0.3-10-Pa is supplied to the slit filter described in Example I. The shaft journal is rotated at a speed of 0.86 m. / s and along the slotted channels is created

.. positive pressure gradient 6.4 x X 10 Pa / m. The initial specific throughput of the clean filter qi 0, / () after 32 h is reduced by 98%. The composition of impurities in the filtered fuel: 0.02% vol. Solid mechanical particles and

5 1.45% by volume} ha.

With conventional filtering of the same type of fuel in a similar filter (with non-rotating shaft journal), the value of qi

 0.57 () after 6 h is reduced by 98% while in the filtered oil there was little mechanical impurities (0.02% by volume) and little dispersed air 0.1% by volume). Thus, the proposed method of fuel cleaning allows, by holding back large and harmful particles of mechanical impurities, to skip air bubbles that are harmless for the subsequent combustion process and simultaneously increase the service life of the filter before the next cleaning (regeneration or replacement).

FIG. 1 shows a diagram of the first variant of the slotted filter; in fig. 2 is a section A-A in FIG. one; in fig. 3 is a plot of pressures arising in the filter chamber along the course of the fluid being cleaned; in fig. 4 is a schematic of a second embodiment of a slotted filter.

FIG. 1 and 3 Р - current pressure in the filter chamber; X - the current longitudinal-axial coordinate, measured from the entrance to the filter channel; P, is the fluid pressure at the inlet to the filter channel (at the point with coordinate Xi); РЗ - pressure at the outlet of the filter channel (at the point with coordinate Хg), Рз - maximum pressure occurring in the filter chamber (at the point with coordinate Xj); X4-coordinate of the end of the filter chamber.

First option. The filter contains a shaft 1 and a casing 2 with nozzles 3 for supplying and for draining the liquid 4, a filter chamber 5 with filter elements b fixed on the casing 2 and made in the form of plates forming the filter channels 7, open to the side of the shaft 1, filter chamber 5 placed between the casing 2 and the shaft 1, is made with a decreasing volume in the course of the movement of the fluid being cleaned. In addition, the casing 2 can be installed eccentric to the axis of the shaft 1. The chamber 8 in front of the filtering elements contains a drainage 9 for removal of contaminants. The direction of rotation of the shaft is indicated by the arrow.

The second option. The filter contains a movable belt 11 and covers 12 installed with a gap to it, fitted with plates 13 installed along the belt and forming filter slots between them, the covers being made decreasing in height in the direction of the tape and containing pipes 14 for supplying for draining the liquid 15, as well as the chamber 16 for collecting contaminants. Frame 17 eliminates the deflection of the movable belt.

Slot filter works as follows.

Through the nozzle 3, source contaminated liquid is introduced into chamber 8. When the shaft 1 rotates in the direction indicated by the arrow in the filter chamber 5 formed by the shaft neck and the housing 2, a hydrodynamic fluid flow is created (similar to the flow in the sliding bearing wedge gap) with a positive pressure gradient dp / dx in section XiXj (Fig. 3) and negative gradient; iaB of blends dr / dx on the XsH site. The filter elements 6 are located in the section XiXj of the filter chamber where positive pressure gradients are created along the slot filter channels 7. Highly dispersed particles under the influence of near-wall hydrodynamic forces arising in a stream with large transverse velocity gradients and positive pressure gradients are repelled from filter elements 6 and carried away with the core of the carrier stream, preventing the process of overgrowth of filter channels. Purified from coarsely dispersed impurities liquid through the pipe 4

0 assigned to the consumer. The impurities retained by the filter are periodically discharged from chamber 8 through drainage 9.

The second variant of the filter works in a similar way, in which the hydrodynamic flow of fluid is created by a movable flax 5 of that 11, slung over the pulleys 10 and resting on the frame 17.

Claims (4)

1. A method of cleaning a liquid from dispersed impurities by flowing a flow to be cleaned through the slit filter channels of a filter septum, characterized in that, in order to expand operational capabilities by preventing the overgrowth of slit filter channels, the latter create a positive pressure gradient dp / dx, the average value of which AR is determined from the ratio P, p 0 VP where P fluid pressure in the slotted channel. Pa; longitudinal axis coordinate current Nata, m; five PI the inlet to the shche-pressure of the fluid on the left channel (at the point with coordinate X |, m). Pa; 2 -the pressure of the fluid at the exit of the slot channel, (at the point with the coordinate X2, m). Pa. 2. A slit filter for cleaning the fluid, containing a housing with connections for supplying and discharging the fluid, a filter chamber with filter elements fixed on the housing and painted in 5 as plates forming slotted filter channels and a shaft, characterized in that, in order to prevent overgrowing filter channels, the filter chamber is placed between the casing and the shaft and is made with a decreasing volume in the course of the fluid being cleaned. 3. The filter according to claim 2, characterized in that the casing is mounted eccentric to the axis of the shaft. 4. Purpose filter for cleaning fluid containing a movable belt and casings installed with a gap to it, forming slotted channels with the ribbon, characterized in that, in order to prevent the filter channel from overgrowing, the casings are provided with plates installed along the belt and forming filter slits between them while the covers are made decreasing in height in the direction of the belt movement. Sources of information taken into account in the examination 1. Japanese Patent No. 16870, cl. 72 C 34, published. 1969. 2. USSR author's certificate number 119519, cl. B 01 D 33/14, 1958. U / 77 /////// 9 ( Fmd