WO1997027928B1

WO1997027928B1 - Device and method for agglomerating and precipitating particles in a gas stream

Info

Publication number: WO1997027928B1
Application number: PCT/FR1997/000164
Authority: WO
Filing date: 1997-01-28
Publication date: 1997-11-20
Anticipated expiration: 1998-07-31

Abstract

The agglomeration and precipitation of particles contained in a turbulent gas stream are disclosed. Specifically, an agglomeration method (13), a precipitation device (10), a combined agglomeration and precipitation assembly, as well as a related separation method, are disclosed.

Claims

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AMENDED CLAIMS f received by the International Bureau on 3 October 1997 (03.10.97); original claims 1-30 replaced by amended claims 1-27 (6 pages)]

1) Agglomeration and precipitation assembly comprising in combination:

(a) an agglomeration device (13) for receiving a stream of turbulent gas containing fine particles in suspension and discharging the stream in which the majority of said fine particles have agglomerated as larger particles, and

(b) a precipitation device (10) for receiving the current exiting the sintering device and for separating the larger particles from the gas stream.

2) Agglomeration and precipitation assembly according to claim 1, characterized in that said agglomeration device for increasing the size of fine particles suspended in a turbulent gas stream comprises:

(a) a conduit having an inlet opening for receiving the stream and an outlet (11B) for discharging the stream, and

(b) a series of filters (15) disposed substantially parallel to each other and spaced apart along the conduit between the aperture and the outlet, each filter extending through the conduit generally in a transverse direction relative to to the current, so that the entire current passes through all the filters successively, (c) each filter having solid portions distributed in the conduit in order to be struck by a portion of the particles and holes distributed in the conduit to allow the free passage of the current.

3) assembly agglomeration and precipitation according to claim 2. characterized in that the number of filters (15) is at least ten.

4) assembly agglomeration and precipitation according to claim 2. characterized in that the number of filters (15) is at least 30.

5) Agglomeration and precipitation assembly according to any one of claims 2, 3 or 4, characterized in that the solid parts of each filter (15) occupy a surface smaller than most of the section of the conduit.

6) assembly agglomeration and precipitation according to any one of claims 2 3 or 4. characterized in that each filter (15) comprises sets of son (16) parallel to each other and extending transversely relative to the others to form a mesh structure, these son forming said solid parts, and spaces between the son forming said holes.

7) Agglomeration and precipitation assembly according to claim 6. characterized in that the ratio of the distance between the son (16) on the thickness of the son is approximately between ten and five.

MODIFIED SHEET {ARTICLE 19) O 97/27928 PC17FR97 / 00164

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8) Agglomeration and precipitation assembly according to any one of claims 2 3 or 4, characterized in that each filter comprises a plate provided with holes.

Agglomeration and precipitation assembly according to any one of claims 2, 3 or 4, characterized in that the spacing of the filters (15) relative to one another in the direction of flow of the current must not be less than about five millimeters.

10) assembly agglomeration and precipitation according to any one of claims 2 3 or 4, characterized in that the filters son!

10 consist of a continuous mesh material successively extending on transverse rods located in the upper part and in the lower part of the conduit.

1) Agglomeration and precipitation assembly according to any one of the preceding claims, characterized in that said i? precipitation device for removing particles contained in a gaseous stream, comprises at least one non-stubborn channel for conveying the stream having a turbulent flow and a series of objects extending along at least one side of each channel , said objects being arranged at close intervals in the direction of flow in order to define between them

20 spaces in which vortices enter from each channel, which causes the accumulation of particles on the surface of said objects after the decline of vortices, wherein said objects consist of at least one corrugated plate. 31

12) set agglomeration and precipitation according to claim 1 1. characterized in that the folds of each of said corrugated plates have a greater depth than the pitch between the folds.

13) Set ^of agglomeration and precipitation according to claim 5 12, characterized in that said depth is approximately four times greater than said pitch.

14) set of agglomeration and precipitation according to any one of claims 1 1 to 13. characterized in that each of said corrugated plates is oriented substantially vertically to allow

H) particles accumulated on their surface to fall into the bottom of an envelope containing said plate or plates and thus defining said channel or channels.

15) Set of agglomeration and precipitation according to the claim

Characterized in that the bottom of the casing is inclined with respect to the horizontal in order to promote the flow of the fallen particles from the surfaces of the corrugated plate (s) to an end of said bottom, then to an outdoor collector.

16) Set of agglomeration and precipitation according to the claim

Characterized in that said particles are liquid and said outer collector comprises a liquid trap. 32

17) assembly agglomeration and precipitation according to claim 15, characterized in that said particles are solid and said outer collector comprises a hopper.

Agglomeration and precipitation assembly according to claim 17, characterized in that said precipitation device comprises a bowl which extends along the bottom of the casing and which encloses the lower portions of said corrugated plates, according to which a a small free space is arranged between the lower ends of said corrugated plates and the bottom of the envelope to collect solid particles fallen from the surface of the plates and guide them underneath said corrugated plates through an opening in the bowl to bring them to a particle evacuation slot at the end of the bottom of the envelope.

19) Agglomeration and precipitation assembly according to claim 18. characterized in that the precipitation device comprises a vibrator for promoting the transfer of solid particles to the outer collector.

20) A method of agglomeration and separation of fine particles of a turbulent gas stream, first comprising the agglomeration of said fine particles in the form of larger particles, and then the separation of said larger particles by precipitation.

21) A method of agglomerating and separating fine particles suspended in a turbulent gas stream (12) according to claim 20. 33

characterized in that the agglomeration step comprises passing the gas stream (12) successively through a series of filters (15) to cause a portion of the particles to strike solid portions (16; 16A). each of the filters to agglomerate to form larger particles, most of said larger particles being re-entrained in the stream (12).

22) Method according to claim 21, characterized in that a portion of said larger particles fall filters.

23) Method according to claim 21, characterized in that the current is passed successively through at least ten filters.

24) Method according to claim 21, characterized in that the current is passed successively through at least 30 filters.

25) Method according to any one of claims 20 to 24. characterized in that the current is passed with the larger particles re-entrained in a particle precipitation device (10).

26) Method according to any one of claims 20 to 24. characterized in that the fine particles consist of a fog.

27) Method according to any one of claims 20 to 25. characterized in that the fine particles consist of dust, steam or smoke.