JPH06262018A - Method and device for separating foreign matter from gaseous medium - Google Patents

Abstract

PURPOSE: To separate a foreign material effectively with a simple constitution by supporting a filter element on an axis rotatably as well as providing an outlet joint inserted between a raw material gas chamber and a clean gas chamber in a state closed by a separation wall. CONSTITUTION: A filter element 8 is arranged in a housing 1 separated into a raw material gas chamber 3 and a clean gas chamber 4 by a separation wall 2. The filter element 8 has two perforated walls 10 separated from each other, while the perforated walls 10 limits a circular filter bed filled with carbon particles by a closed front side. The filter element 8 is supported rotatably on an axis and is provided with an outlet joint 15 arranged so as to penetrating a separation chamber 2 in a sealed state between a raw material gas chamber 3 and a clean gas chamber 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for separating foreign substances such as aerosol, gas and vapor from a gaseous medium according to the preamble of claim 1 and a filter layer for separating foreign substances. Regarding cleaning methods.

[0002]

2. Description of the Prior Art A stationary filter defined between two perforated walls--a filter having a floor filled with sand or carbon granules--a filter for bulk material with elements--is a DE-OS.
No. 3012911. The filter element is fixedly mounted in the filter housing. When cleaning the filter, the nozzle tube protruding from the inner space of the filter element is used.
Compressed air is intermittently blown to the filter-bed through the bush. The nozzle tube is rotatably supported or vertically movable. This known bulk material filter is provided for separating dust from a raw material gas containing dust, and is suitable for separating an aerosol. In the case of this filter, it is impossible to separate gas and vapor since there is a possibility of taking in a fluid having an adsorptive property. In particular, if foreign substances tend to stick or harden, blowing compressed air to clean foreign substances adsorbed on the filter bed is very inefficient.

The use of silica sand granulate to separate aerosols from a gas stream is disclosed in DE-OS 2714972. The layers of granules are contained in a polygonal container with perforated walls which are arranged one above the other in a filter housing. During cleaning, hot air or steam is sprayed onto the bed of particles in a direction opposite to the direction of flow of the gas to be cleaned. Regenerating the filter layer using hot air or steam is energy intensive.
It is very expensive in terms of cost. When using steam for regeneration, foreign substances are adsorbed, so that the amount of foreign substances that can be removed is very small. The need to replace the layers of granulate increases the operating costs and the costs required for maintenance. Although the configuration of the separation device is expensive, operational abnormalities and outages frequently occur.

A filter used for cleaning a raw material gas containing dust is DE-OS 24339.
No. 43. This filter is composed of a rotatable filter drum on which a filter material on which dust separated from a raw material gas is deposited is stretched. The cleaned gas is discharged through the hollow shaft of the filter drum. Filter-
It is configured to clean the filter by spraying fluid inside the filter drum while rotating the drum, and by loosening the filter cake.
However, in the case of a deposited layer adsorbed at a deep position, it is impossible to obtain an effective adsorbing action by stretching the filter material. Since the diameter of the hollow shaft is small,
The velocity of the clean gas exiting the hollow shaft is increased, which results in high flow and pressure losses. If the flow velocity is set low in order to eliminate this drawback, the structure of the filter becomes very large.

Dust separator with a filter bed made up of granular filter material arranged to improve the degree of separation by applying a non-intermittent DC voltage, ie a continuous DC voltage. -Is EP-OS35973
No. In this dust separator,
The electrodes are located at various locations along a cylindrical jacket surrounding the inner wall, outer wall or filter-floor. If the DC voltage is continuously applied in this way, it is not necessary to take care to prevent a voltage flash path (spark running that occurs under a high voltage) from occurring.
Therefore, a relatively low voltage can be used to operate the dust separator while maintaining a reasonable degree of separation. The thickness of the filter bed of this known dust separator is relatively large and is sized from 25 to 100 mm. This dust separator is not suitable for use to separate gases and vapors, since no additional adsorption means can be provided. Regeneration of the filter bed takes place by exchanging the filter material fed through the centrally located transfer tube. Since the transfer tube is arranged as described above, it is expensive to manufacture the dust separator, and the breakdown and the shutdown during the operation are likely to occur.

[0006]

The object of the present invention is an apparatus suitable for separating foreign substances such as aerosol, gas, and vapor from a gaseous medium, and can be used with a simple structure. In addition, the weight is light and the space is
The object is to provide a device that requires less space.

[0007]

According to the invention, there is provided an apparatus of the type mentioned at the outset, which is constructed in accordance with the characterizing features of claim 1 for solving the abovementioned problems. Reference is made to claims 2 to 9 for advantageous embodiments of the invention. A method for separating an aerosol and cleaning a filter bed is described in Claim 1.
As described in 0.

[0008]

When the medium containing the harmful substances flows through the filter bed, the harmful substances are adsorbed on the surface of the particles. Cleaning of the filter-floor is done by rotating the filter-element. Due to the action of the centrifugal force that accompanies the rotation of the filter element, the adsorbed harmful substances are released and are recovered as they are as the filter element is driven by the motor. The separating ability of the filter element can be improved by applying a DC voltage intermittently.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings illustrating the embodiments of the present invention. Housing 1
Is separated into a raw material gas chamber-3 and a clean gas chamber-4 by a separation wall 2. The source gas chamber-3 is an inflow joint 5 for supplying a gaseous medium containing a foreign substance such as aerosol, gas or vapor.
The clean gas chamber-4 is equipped with a drainage joint 6 for discharging the medium from which foreign substances have been removed. An extraction joint 7 for discharging the separated foreign substance is provided at the bottom of the source gas chamber-3.

One or more filter elements 8 are arranged in the feed gas chamber-3. Each filter
The element 8 is composed of a hollow cylinder and comprises two spaced perforated walls 9 and 10 defining an annular filter-bed 11. The filter element 8 may be designed to have a polygonal shaped cross section instead of a circular cross section. The upper and lower surfaces of the annular space surrounded by the perforated walls 9 and 10 are closed. The lower surface of the annular space forms part of a bottom plate 12 closing the lower part of the filter element 8. The upper area of the perforated walls 9 and 10 is constructed so that gas cannot pass freely through it, which limits the expansion space 13.

The bottom plate 12 and the perforated wall 9 inside the filter element 8 define an internal space 14, the upper end of which passes into the outlet fitting 15. The outlet joint 15 is suspended in the annular space 4 by a collar 16 protruding outward. An elastic thin plate 17 that surrounds the outlet joint 15 with an annular gap and is connected to the separating wall 2 is attached to the outlet portion of the outlet joint 15 while limiting the separating wall 2. The inner circumference of the circular cross section of the thin plate 17 is dimensioned larger than the outer circumference of the outlet joint 15 and smaller than the outer circumference of the collar 16. When a pressure difference occurs between the clean gas chamber-4 and the source gas chamber-3, the thin plate 17 abuts on the collar 16 from below. When the pressure is balanced on both sides of the separating wall 2, the thin plate 17 is pushed down and the thin plate 1
A gap is created between 7 and the outlet fitting 15. Alternatively, instead of the sealing described above, a packing abutting the outlet fitting 15 at any stage of operation may be used.

The filter element 8 is preferably rotatably supported and has a shaft piece 18 fixed to the bottom plate 12. The shaft piece 18 is rotatably supported by a bearer ring 19 standing on the bottom of the source gas chamber-3. In the embodiment shown in FIG. 3, the shaft piece 1
Reference numeral 8 is provided so as to extend through the bottom of the source gas chamber-3 and is also connected to the motor driving device 20. The filter element 8 is rotatably supported via a drive device 20, which is preferably embodied as an electric motor.

In the embodiment shown in FIG. 1, the inner wall 9,
The filter element 8 is arranged to rotate under the action of a fluid tangentially directed to the outer wall 10 or the inner or outer component of the filter element 8. In order to realize this construction, it is necessary that the outlet fitting 15 is provided through and the supply line 21 is plugged into the inner space 14 of the filter element 8. Internal space 14
One or more stationary nozzles 2 which are distributed over the height of the outlet shaft and whose outlet axes are tangentially directed to the inner wall 9 or to the inner component of the filter element 8.
2 or a nozzle 22 movable in the space is connected to the supply line 21. The supply line 21 extends outwardly through the clean gas chamber-4 and the valve 2
It is connected to the supply line 24 which can be shut off by 3. The fluid is supplied to the supply line 24 through the pump 25. Fluid flows through the valve 23 through the filter-elements 8 arranged in any order or combination. Therefore, the plurality of filter elements 8 can be operated by the fluid supplied by driving the pump 25.

The device described above is particularly suitable for separating atomized cooling lubricants from exhaust gas. This atomized lubricant substance tends to stick. The filter-bed 11 is composed of a sediment, preferably a unitary stationary deposit of carbon grains. The carbon particles have a smooth closed surface, and prevent the adsorbed foreign substances from strongly adhering. Furthermore, by appropriately selecting the type of carbon, it is possible to control the resistance to chemical substances, heat resistance, and usefulness. The carbon particles are made into a small cylindrical shape having a diameter of 2.4 mm and a height of 3.5 mm. When using such carbon particles, the spacing between the perforated walls 9 and 10,
That is, the thickness of the filter-floor 11 can be sized to 20 mm. Therefore, the filter element 8 having good separation performance can be made small.

A gaseous medium containing a foreign substance such as an aerosol passes through the inflow joint 5 and the raw material gas chamber-3.
Flows in. When the filter element 8 is stationary, the medium flows through the filter bed 11, whereupon the aerosol is adsorbed on the surface of each carbon particle. The aerosol-depleted medium passes from the inner space 14 of the filter element 8 through the outlet fitting 15 to the clean gas chamber-4.
From the clean gas chamber 4 through the outlet fitting 6. Clean gas chamber
Since the pressure inside 4 is lower than the pressure inside the source gas chamber-3, the thin plate 17 is in close contact with the collar 16 and seals. A liquid is sprayed onto the inflowing medium when gas or vapor as well as atomized foreign matter has to be separated. In this case, the gas or condensed vapor adsorbed by the spraying action of the liquid is adsorbed on the surface of the carbon particles.

By applying a high voltage to the filter element 8, the separation performance can be improved. The high voltage is preferably applied in the form of a DC voltage. Application of high voltage is intermittent. That is, the application of the high voltage is interrupted after a short time interval. Thus, each time the DC voltage is intermittently applied, the voltage flash path formed in the bookmark is interrupted, or in the process of forming the voltage flash path,
It is possible to prevent a higher voltage from being applied than when a DC voltage is continuously applied. Since the degree of separation increases as the applied voltage is increased, intermittent application of the DC voltage can ensure a higher degree of separation than when the voltage is continuously applied.

As shown in FIG. 4, a high voltage is intermittently applied to the poles provided on the inner wall 9 and the outer wall 10 of the filter element 8 to generate an electric field. By providing insulation at the connection points, both walls can be electrically isolated from each other.

If the spacing between the inner wall 9 and the outer wall 10 is large, they are distributed around the filter element 8, such as a conductive wire or a thin conductive rod, as shown in FIG. Conducted conductor 27 is used as one pole. The poles of the conductor 27 may be poled positively and negatively alternately, or may be poled according to another order different from this.

If the foreign substance to be separated from the gaseous medium has a high electrical conductivity, as shown in FIG.
A conductive cylindrical or polygonal jacket 26 surrounding the filter element 8 with sufficient spacing is used as one pole. The jacket 26 must have a sufficiently large free flow-through area in order not to obstruct the flow-through of the gaseous medium. In this variant, the inner wall 9 and / or the outer wall 10 of the filter element 8 serve as the second pole. This variant is suitable for separating highly conductive aerosols. Jacket 2 that functions as an electrode
Due to the electrically insulating action of the gaseous medium existing between 6 and the filter element 8, the occurrence of a voltage flash can be effectively prevented. The embodiments shown in FIGS. 4, 5, and 6 may be used in appropriate combination.

In cleaning the filter bed 11, the feed gas chamber-3 and the clean gas chamber-4 are supplied after the supply and discharge of the gaseous medium are completed.
Equilibrate the pressure between. This lifts the lamella 17 from the collar 16 and leaves the filter element 8 free. In the case of an embodiment in which the packing is fixedly mounted, it is necessary to interrupt the feeding and draining of the gaseous medium. After that, the filter element 8 is rotated, and the adsorbate is removed from the filter bed 11 to the outside by the action of the centrifugal force generated by the rotation. Unless a supplementary fluid is supplied to the housing 1, the adsorbate that has been removed again during cleaning falls in its original form and can be reused without any treatment. As the filter element rotates, the particulate deposits of the filter bed 11 are forced into the expansion space 13. During the cleaning of the filter layer, the filter layer is loosened because the deposit of particles can expand as the filter element 8 rotates. This facilitates the removal of the adsorbed foreign substance. Further, when the filter layer is loosened, rubbing or stripping using an adhesive may be performed to positively enhance the effect of the cleaning operation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a device for separating foreign substances, which is constructed according to an embodiment of the present invention, taken along its length.

2 is a plan view of the device shown in FIG. 1. FIG.

FIG. 3 is an explanatory diagram illustrating in detail the configuration of a filter-element.

4 to 6 are longitudinal sectional views of a filter element with electrodes arranged in various ways.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Separation chamber 3 Raw material gas chamber-4 Clean gas chamber-5 Inflow fitting 6 Discharge fitting 7 Extraction fitting 8 Filter element 9, 10 Perforated wall 11 Filter floor 12 Bottom plate 13 Expansion space 14 Internal space 15 Outlet joint 16 Color 17 Thin plate 18 Shaft piece 19 Beering 20 Motor drive device 21 Supply line 22 Nozzle 23 Valve 24 Supply line 25 Pump 26 Annular jacket 27 Conductor

Claims (10)

[Claims] 1. A housing (1) divided by a separation wall (3) into a source gas chamber (2) and a clean gas chamber (4), the front side of which is closed. Annular filter filled with granular material
Gaseous medium to aerosol comprising one or more filter-elements (8) with two spaced-apart perforated walls (9, 10) defining a floor (11) , A device for separating foreign substances such as gas, steam, etc., which is an internal space (1) of the filter element (8).
4) In a device configured to communicate with the clean gas chamber (4), the filter element (8) is rotatably journalled and closed by the separating wall (2). Raw material gas chamber- (3) and clear
The outlet joint (1
5) A device comprising: 2. A sealing means surrounds the outlet fitting (15) of the filter element (8) at radially spaced intervals, and the source gas chamber (3) and the cleaner.
Characterized in that it comprises an elastic thin plate (17) adapted to abut the collar (16) of the outlet joint (15) under the action of a pressure difference between it and the gas chamber (4). The device according to claim 1. 3. Device according to claim 1, characterized in that the filter element (8) comprises a motor drive (20). 4. A fluid supply line (21) comprising one or more nozzles (22) distributed in the height direction is provided with an internal space (1) of the filter element (8).
Device according to claim 1 or 2, characterized in that it projects into the interior (4) and the outlet shaft of the nozzle (22) is tangentially oriented towards the filter bed (11). 5. A valve (23) is arranged in the supply line (21) and the supply lines (21) of the plurality of filter elements (8) are connected to a common pump (25). The device according to claim 4, wherein 6. The upper area of the perforated wall (9, 10) is configured to be gas impermeable and the filter
In the stationary state of the element (8), the gas-impermeable region occupies only part of the filter-bed (11), while in the rotating state of the filter-element (8): 6. Device according to claim 1, characterized in that the gas-impermeable region completely disappears from the filter bed (11). 7. Intermittently applied high-voltage poles are respectively the inner wall (9) and the outer wall (10) of the filter element (8).
7. Device according to claim 1, characterized in that it is provided in the. 8. A conductor (27) which is poled to the same pole or which is poled alternately in any order, is arranged between the inner wall (9) and the outer wall (10). 7. Device according to claim 1, characterized in that the inner wall (9) and / or the outer wall (10) is connected to one pole. 9. The filter element (8) is surrounded by an annular jacket (26) made of a conductive material, spaced apart and having a sufficiently large free-flow area, and intermittently. One pole of a high voltage applied to the jacket (26) is provided in the jacket (26), or a plurality of poles are provided in the jacket (26) in an electrically isolated partial region. 7. A device according to any one of claims 1 to 6, wherein: 10. A device for separating foreign substances such as aerosols, gases and vapors from a gaseous medium using a device according to one or more of claims 1 to 9 and a filter. -In a method for cleaning a bed, in the condition that the filter element is stationary, the gaseous medium is guided through the filter layer and after switching the supply and drainage of the gaseous medium. , Balancing the pressure between the source gas chamber and the clean gas chamber and rotating the filter element.