Venturi scrubber

Claim 2

In a venturi scrubber having a first region for receiving a primary stream of gas, a second region extending from the downstream end of the first region and converging in the downstream direction, a third region of reduced diameter extending in a smooth inner surface configuration at the downstream end of the second region and forming the venturi throat, and a fourth region extending in a smooth inner surface configuration from the downstream end of the third region and diverging in the downstream direction, means to inject liquid in droplet form into the primary stream of gas, the improvement which comprises: at least one first duct opening into the scrubber at a point located within a first zone encompassing the downstream portion of the third region and the upstream portion of the fourth region; and means for directing a secondary stream of gas through the first duct into the first zone of the scrubber whereby the gas enters the first zone at an acute angle to the primary stream of gas so as to cause a substantial increase in turbulence within the primary stream of gas and a resultant increase in the surface area of the liquid droplets in said stream.

Claim 3

The improvement according to claim 1 wherein the means for directing a secondary stream of gas comprises at least one second duct extending from the first duct and opening into the scrubber at a point within a second zone encompassing the first region and the upstream portion of the converging region of the scrubber whereby a portion of the primary gas stream is diverted into the second duct to form the secondary gas stream.

Claim 4

The improvement according to claim 2 further including valving means to controllably close the ducts.

Claim 5

The improvement according to claim 2 wherein the opening between the first duct and the first zone is an annular opening extending continuously around the first zone.

Claim 6

The improvement according to claim 4 wherein the first duct is of annular cross section and surrounds the venturi throat, the first duct opening into the throat region in a continuous annular opening.

Claim 7

The improvement according to claim 5 further including a plurality of vanes attached to the walls of the scrubber at the opening between the first duct and the converging region, the vanes being movable between a first position covering the opening and forming a smooth transition between the entrance and converging regions and a second position in which the opening is uncovered.

Claim 8

The improvement according to claim 5 which includes means to vary the size of the annular opening between the first duct and the first zone.

Claim 9

The improvement according to claim 5 which includes means to vary the size of the annular opening between the first duct and the converging region.

Claim 10

A venturi scrubber, comprising: first wall means defining an inlet region; second wall means extending from the downstream end of the first wall means and converging in the downstream direction; third wall means extending in a smooth inner path configuration from the downstream end of the second wall means and defining the throat of the venturi; fourth wall means extending from the downstream end of the third wall means and diverging in the downstream direction; at least one duct opening into the venturi at a point within a zone extending between the downstream portion of the throat and the upstream portion of the fourth wall means to inject a secondary stream of gas into the primary gas stream through the scrubber, the secondary stream being injected at an acute angle to the primary gas stream; said duct extending from the opening within the zone to a second opening in the second wall means wherein the openings at each end of the duct are annular openings extending substantially the full circumference of the scrubber and the duct surrounds the wall means between the two openings; and nozzle means for injecting a liquid into the stream of gas passing through the venturi throat.

Claim 11

A venturi scrubber, comprising: first wall means defining an inlet region; second wall means extending from the downstream end of the first wall means and converging in the downstream direction; third wall means extending in a smooth inner path configuration from the downstream end of the second wall means and defining the throat of the venturi; fourth wall means extending from the downstream end of the third wall means and diverging in the downstream direction; at least one duct opening into the venturi at a point within a zone extending between the downstream portion of the throat and the upstream portion of the fourth wall means to inject a secondary stream of gas into the primary gas stream through the scrubber, the secondary stream being injected at an acute angle to the primary gas stream; said duct extending from the opening within the zone to a second opening in the second wall means wherein the openings at each end of the duct are annular openings extending substantially the full circumference of the scrubber and the duct surrounds the wall means between the two openings; and nozzle means for injecting a liquid into the stream of gas passing through the venturi throat.

Claim 12

The venturi scrubber according to claim 9 wherein there are a plurality of ducts, the openings of the ducts in the first zone and those in the second wall means each being arranged in a circle around the wall means.

Claim 13

The venturi scrubber according to claim 9 further including valve means to control gas flow through the duct.

Claim 14

The venturi scrubber according to claim 9 further including means for forcing the secondary gas stream through the duct from a source external to the scrubber.

Claim 15

The venturi scrubber according to claim 9 further including additional nozzle means for injecting liquid in droplet form into the secondary gas stream passing through the duct.

Claim 16

The venturi scrubber according to claim 9 wherein the duct surrounds the second and third wall means, a continuous gap being provided between the first and second wall means to provide an upper opening into the duct, and a continuous gap being provided between the third and fourth wall means to provide a lower opening into the duct.

Claim 17

The venturi scrubber according to claim 14 further including means to vary the size of the lower opening into the duct.

Claim 18

The venturi scrubber according to claim 14 further including means to vary the size of the upper opening into the duct.

Claim 19

The venturi scrubber according to claim 16 wherein the means to vary the size of the opening comprises a sleeve telescopingly received on the upper end of the second wall means.