US3279156A

US3279156A - Gas-cleaning apparatus

Info

Publication number: US3279156A
Application number: US419786A
Authority: US
Inventors: Wilhelmsson Gunnar; Gustavsson Lennart
Original assignee: Svenska Flaktfabriken AB
Current assignee: Svenska Flaktfabriken AB
Priority date: 1963-12-21
Filing date: 1964-12-21
Publication date: 1966-10-18
Anticipated expiration: 1983-10-18
Also published as: BE657390A

Description

G. WILHELMSSON ETAL 3,279,156

Oct. 18, 1966 GAS-CLEANING APPARATUS 2 Sheets-Sheet 1 Filed D60. 21, 1964 INVENTORS. GUNNAR WILHELMSSON LENNART GUS TAVSSON ATTYS.

Oct. 18, 1966 G WILHELMSSON ETAL. 3,279,156

' GAS-CLEANING APPARATUS Filed Dec. 21, 1964 2 Sheets-Sheet 2 FIGZ.

uanu a INVENTORS; GUNNAR WILHELMSSDN LENNART' GUS TAVSSON ArTTYS.

United States Patent 3,279,156 GAS-CLEANING APPARATUS Gunnar Wiihelmsson, Vaxjo, and Lennart Gustavsson, Lockebo, Jonkoping, Sweden, assignors to Aktiebolaget Svenska Flaktfabriken, toclrhoim, Sweden Filed Dec. 21, 1964, Ser. No. 419,786 Claims priority, application Sweden, Dec. 21, 1963, 14,4il4/63 Claims. (Cl. 55-223) The present invention relates to a device for cleaning gases and in particular for cleaning gases that are dust laden, the cleaning being carried out in a two-stage or twostep device.

Gas cleaners or separators of the type to which the present invention relates are preferably used in steel factories, foundry plants, workshops, mines, and the like. Their use is prevalent where the dry process ha proven unsatisfactory. The amounts of exhaust gases in establishments of the above mentioned type are usually relatively large with the result that the conventional apparatus for cleaning gases in two steps were usually difficult to place and required too much space.

The present invention provides an arrangement for cleaning the gases in two stages and comprises a casing accommodating a first section wherein a liquid is added to and mixed with the inflowing gas for agglomerating the dust particles and a subsequent second section in which the dust and liquid particles accompanying the gas are separated, the arrangement including communication of the separators with a liquid tank.

The present invention provides a novel solution to the problem of combining the required means for the two cleaning steps in a compact unit of low mounting height which is adapted to fit easily into a plant and which is to be connected to the gas-producing apparatu without the necessity of complicated additional duct work. Moreover, the cleaning device is assembled of standardized units in such a manner that one unit in the agglomerating section cooperates with a specific number of separators in the separating section.

According to the present invention there is provided a device for cleaning dust-laden gases including a casing having a first section wherein liquid is added to and mixed with a dust-laden gas for agglomerating the dust particles; a second section in which the dust and liquid particles are separated from the gas; and a liquid tank communicating with both said section; said agglomerating section comprising an inlet chamber for said dust-laden gases; a plurality of gas nozzles arranged in parallel in the lower end of said inlet chamber and being directed toward said liquid tank; said nozzles being constituted by convergent side walls terminating at their lower ends with inwardly directed throttling flanges; liquid supply chambers arranged on each side of each nozzle and being disposed parallel therewith, liquid outflow openings in the upper ends of said chambers adapted to emit a film of liquid over the convergent side walls of said nozzles and to flow downwardly therealong to said throttling flange; said separating section comprising a plurality of tubular cyclone separators arranged in rows in alignment with said nozzles, the number of separators in each row being sulficient to accommodate the flow from one associated nozzle, each said separator including a gas inlet communicating with the space above said liquid tank; a gas outlet in each separator; a collecting chamber for the cleaned gas common to all of said separator outlets; said chamber being disposed above said outlets and being defined by a partition wall; an outlet in the lower end of each separator for separating dust and liquid particles from said gas; and a conveying pipe extending from "ice each lower outlet downwardly to terminate below the level of the liquid in said tank.

The invention will be described in detail with reference to the accompanying drawing showing, by way of example, one ernbodiment thereof, in which:

FIG. 1 is a perspective view of apparatus embodying the present invention with portions broken away;

FIG. 2 is a sectional view taken on the line 22 of FIG. 1; and

FIG. 3 is a reduced sectional view taken on the line 33 of FIG. 2.

As shown in the drawing, the apparatus comprises a casing 1 enclosing cleaning and separating apparatus that is in communication respectively with an inlet 2 for the gas to be cleaned and an outlet 3 for the discharge of the cleaned gas. The inlet 2 communicates with a chamber 4 having an inspection port (not numbered), and the gases passing downwardly through the chamber 4 are directed through a plurality of parallel rectangular exhaust nozzles 5 which, in the illustrated embodiment, open directly to the liquid tank 6 placed in the lower end of the apparatus.

It will be seen that the nozzles 5 include convergent side walls 7 which terminate at their lower ends with an inwardly directed flange 8 for throttling the gases.

The upper ends of the nozzle side walls; 7 are connected to liquid supply chambers 9 that are arranged in parallel with the nozzles, each chamber 9 being provided with a row of outflow openings 110. The supply chambers 9 are connected to a common distribution line 20 which, by means of a pump 21, is supplied with liquid from the tank 6 in the lower end of the apparatus. In order to obtain an effective and uniform liquid distribution to the nozzles 5, the outflow openings 10 of the supply chambers 9 are preferably placed in the plane'upper surface of the chambers as shown.

It will be seen from the drawing that the embodiment illustrated includes five banks of supply chambers with the three central banks being located between the side walls 7 of adjacent nozzles 5. In other words, aside from the supply chambers adjacent the outer walls of the casing, the remaining supply chambers are each common to two adjacent nozzles.

The chambers 9 are provided on their upper surfaces with a bar 11 that is turned on edge and which extends undulatory of the openings to ensure a uniform liquid distribution to both sides of each of the central nozzles. Therefore, the cleaning liquid supplied through the openings 10 is distributed half to one side and half to the other to provide a downward flow along the side walls 7 of the nozzles 5 in the form of a film which completely covers the wall surfaces.

As the liquid film flows over throttling flange 8, it is caught by the downward gas flow and atomized for effecting the agglomerating of the dust particles. The coarse dust particles and liquid drops are precipitated when the gas gets into contact with the surface of the liquid in the tank 6 while the remaining gas is deflected and is caused to flow into the adjacent separation section 12.

The separation section comprises a plurality of upwardly extending tubular cyclone separators 13 that are arranged in rows. Each row of separators 13 is in line with an associated nozzle 5. Each separator 13 is provided with a tangential gas inlet 14 that communicates with the free space between the nozzle opening between the flanges 8 and the surface of the liquid in the tank 6, and to ensure uniform distribution of the gas from the agglomerating section between the individual separator 13 in each row thereof, the separators 13 are arranged in a step fashion with their level decreasing from the agglomerating section in a progressive manner. It will be also 3 noted that each separator is provided at its upper terminal end with a gas outlet which communicates with a common collecting chamber 17 for the discharge through the outlet 3 of the cleaned gas. The outlet chamber 17 includes a partition wall 16 which is also formed in a step fashion, and an inspection port (not numbered).

The bottom of each separator 13 is inclined toward a dust outlet 18 which, in turn, is connected to 'an outlet pipe 19 that extends downwardly to terminate below the level of the liquid in the tank 6. Each tangential gas inlet 14 is located immediately above the bottom of its associated separator.

In operation, the gases progress through the apparatus in the directions indicated by the arrows A to F inclusive in FIG. 2. Dust-laden gas enters the chamber 4 through the inlet 2, as indicated at A, and progresses downwardly through the nozzles 5, as indicated at B. A gas cleaning liquid is pumped through the distribution line and into the associated liquid supply chambers 9 and through the openings 10 in the upper ends thereof. The liquid then proceeds downwardly along the side walls 7 of the nozzles in the form of a film and as this film flows over the throttling flange 8, it is intersected by the downward gas flow and is atomized thereby to gather the dust particles. As previously mentioned, the coarser dust particles and liquid will drop straight downwardly into the tank 6 whilst the remaining gas is deflected such as at arrow C to flow into the inlets 14 of the separators 13 as shown at D. In the cyclone separators, the clean gas swirls upwardly, and the dust and liquid particles remaining flow down through the outlets 18 and proceed downwardly through pipes 19 into the liquid in the tank 6 whilst the cleaned gases enter the collecting chamber 17, as shown at E, and are exhausted, as shown at F, through the outlet 3. The dust particles separated in both the first and the second stages settle in the lower end of the tank 6 where they accumulate and are picked up by a screw conveyor 22 thereby to be carried to a discharging elevator 23 to be removed from the device.

What we claim is:

1. A device for cleaning dust-laden gases including a casing having a first section wherein liquid is added to and mixed with a dust-laden gas for agglomerating the dust particles; a second section in which the dust and liquid particles are separated; and a common liquid tank underlying both said sections; said agglomerating section comprising (a) an upper inlet chamber for said dust-laden gases;

(b) a plurality of gas nozzles arranged in parallel in the lower end of said inlet chamber and being directed toward and spaced above the liquid level in said tank;

(c) said nozzles having an opening in form of a rectangular slot and being constituted by convergent side walls terminating at their lower ends in throttling flanges directed inwardly of said opening;

(d) liquid supply chambers arranged on each side of each nozzle and being disposed parallel therewith;

(e) liquid outflow openings in the upper ends of said chambers adapted to emit a film of liquid over the convergent side walls of said nozzles and to flow downwardly therealong to said throttling flange; said separating section comprising (f) a plurality of tubular cyclone separators arranged in rows in alignment with said nozzles, the number of separators in each row being sufficient to accommodate the flow from one associated nozzle;

(g) each said separator including a lower gas inlet communicating with the space between said nozzle openings and said liquid tank;

(h) an upper gas outlet in each separator;

(i) a collecting chamber for the cleaned gas common to all said separator outlets; said chamber being disposed above said outlets and being defined by a partition wall;

(j) an outlet in the bottom of each separator for receiving dust and liquid particles separated from said gas therein; and

(k) a conveying pipe extending from each bottom outlet downwardly to terminate below the level of the liquid in said tank.

2. A device according to claim 1 including pump means connected to said liquid tank and a common distribution line interconnecting said pump with each liquid supply chamber of the agglomerating section.

3. A device according to claim 1 wherein said chambers have plane upper surfaces located between the nozzles and common to two adjacent nozzles; the outflow openings of the liquid supply chambers being disposed in said upper surfaces; each said upper surface being provided with a bar turned on edge and extending undulatory between the outflow openings for ensuring a uniform liquid distribution to the walls of the nozzles on both sides of each chamber.

4. A device according to claim 1, wherein the tubular separators located in each row are arranged in a stepped manner, the level of the gas inlets thereof decreasing stepwise from the level of the nozzles in the agglomeration section toward the level of the liquid in the tank, and wherein the partition wall which defines the collecting chamber and into which the clean gas outlets open has a similarly stepped configuration at the level of said upper inlet chamber.

5. A device according to claim 2, wherein the separators are provided with a bottom inclined toward the bottom outlet and with a tangential gas inlet located immediately above the said bottom.

References Cited by the Examiner UNiTED STATES PATENTS 2,899,183 8/1959 Umbricht et al. 2611 12 X 3,061,994 11/1962 Mylting 346 3,085,793 4/1963 Pike et al 2611 12 3,131,237 4/1964 Collins 55257 X 3,138,442 6/1964 Krantz 55235 X 3,142,548 7/1964 Krantz 5589 3,171,401 3/1965 McDuffee 26197 X FOREIGN PATENTS 1,107,647 5/1961 Germany.

15,225 7/ 1901 Great Britain. of 1901 ROBERT F. BURNETT, Primary Examiner. D. K. DENENBERG, Assistant Examiner.

Claims

1. A DEVICE FOR CLEANING DUST-LADEN GASES INCLUDING A CASING HAVING A FIRST SECTION WHEREIN LIQUID IS ADDED TO AND MIXED WITH A DUST-LADEN GAS FOR AGGLOMERATING THE DUST PARTICLES; A SECOND SECTION IN WHICH THE DUST AND LIQUID PARTICLES ARE SEPARATED; AND A COMMON LIQUID TANK UNDERLYING BOTH SAID SECTIONS; SAID AGGOLMERATING SECTION COMPRISING (A) AN UPPER INLET CHAMBER FOR SAID DUST-LADEN GASES; (B) A PLURALITY OF GAS NOZZLES ARRANGED IN PARALLEL IN THE LOWER END OF SAID INLET CHAMBER AND BEING DIRECTED TOWARD AND SPACED ABOVE THE LIQUID LEVEL IN SAID TANK; (C) SAID NOZZLES HAVING AN OPENING IN FORM OF A RECTANGULAR SLOT AND BEING CONSTITUTED BY CONVERGENT SIDE WALLS TERMINATING AT THEIR LOWER ENDS IN THROTTLING FLANGES DIRECTED INWARDLY OF SAID OPENING; (D) LIQUID SUPPLY CHAMBERS ARRANGED ON EACH SIDE OF EACH NOZZLE AND BEING DISPOSED PARALLEL THEREWITH; (E) LIQUID OUTFLOW OPENINGS IN THE UPPER ENDS OF SAID CHAMBERS ADAPTED TO EMIT A FILM OF LIQUID OVER THE CONVERGENT SIDE WALLS OF SAID NOZZLES AND TO FLOW DOWNWARDLY THEREALONG TO SAID THROTTLING FLANGE; SAID SEPARATING SECTION COMPRISING (F) A PLURALITY OF TUBULAR CYCLONE SEPARATORS ARRANGED IN ROWS IN ALIGNMENT WITH SAID NOZZLES, THE NUMBER OF SEPARATORS IN EACH ROW BEING SUFFICIENT TO ACCOMMODATE THE FLOW FROM ONE ASSOCIATED NOZZLE; (G) EACH SAID SEPARATOR INCLUDING A LOWER GAS INLET COMMUNICATING WITH THE SPACE BETWEEN SAID NOZZLE OPENINGS AND SAID LIQUID TANK; (H) UN UPPER GAS OUTLET IN EACH SEPARATOR; (I) A COLLECTING CHAMBER FOR THE CLEANED GAS COMMON TO ALL SAID SEPARATOR OUTLETS; SAID CHAMBER BEING DISPOSED ABOVE SAID OUTLETS AND BEING DEFINED BY A PARTITION WALL; (J) AN OUTLET IN THE BOTTOM OF EACH SEPARATOR FOR RECEIVING DUST AND LIQUID PARTICLES SEPARATED FROM SAID GAS THEREIN; AND (K) A CONVEYING PIPE EXTENDING FROM EACH BOTTOM OUTLET DOWNWARDLY TO TERMINATE BELOW THE LEVEL OF THE LIQUID IN SAID TANK.