Method and wet scrubber for removing particles from gases

Patent metadata

Field	Value
Publication number	US-9895644-B2
Application number	US-201415104799-A
Country	US
Kind code	B2
Filing date	Dec 18, 2014
Priority date	Dec 20, 2013
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

Provided are a method and to a wet scrubber for removing particles from gas. The wet scrubber includes a second vertical cylindrical vessel having a second upper end for receiving an accelerated stream of liquid- and particles-laden gas from a vertically oriented venturi channel and a second lower end for feeding the accelerated stream of liquid- and particles-laden gas to a swirl generator. The second vertical cylindrical vessel and the swirl generator are arranged in a vertical cylindrical separation space of a first vertical cylindrical vessel. The swirl generator is arranged above the liquid tank.

First claim

The invention claimed is:

1. A method for removing particles from gas, wherein said method comprises:
a first gas feeding step for feeding a stream of particles-laden gas into a gas inlet of a wet scrubber,
a liquid feeding step for feeding liquid into the stream of particles-laden gas to form a stream of liquid- and particles-laden gas,
an acceleration step for feeding the steam of liquid- and particles-laden gas through a vertically oriented venturi channel of the wet scrubber to raise the velocity of the stream of liquid- and particles-laden gas to form an accelerated stream of liquid- and particles-laden gas, wherein the vertically oriented venturi channel having a circular cross-section form,
a swirl step for feeding the accelerated stream of liquid- and particles-laden gas into a swirl generator of the wet scrubber for converting the accelerated stream of liquid- and particles-laden gas into a cyclonic stream of liquid- and particles-laden gas,
a second gas feeding step for feeding the cyclonic stream of liquid- and particles-laden gas from the swirl generator through a gas opening into a vertical cylindrical separation space of a first vertical cylindrical vessel of the wet scrubber for separating liquid and solids from the cyclonic stream of liquid- and particles-laden gas in the cylindrical separation space of the first vertical cylindrical vessel of the wet scrubber by means of the cyclonic motion of the cyclonic stream of liquid- and particles-laden gas and for forming a stream of scrubbed gas, wherein the first vertical cylindrical vessel having an first upper end and a first lower end,
a gas discharging step for removing the stream of scrubbed gas from the vertical cylindrical separation space of the first vertical cylindrical vessel of the wet scrubber through a gas outlet in fluid connection with the vertical cylindrical separation space of the first vertical cylindrical vessel, wherein the gas outlet is arranged at a level above the gas opening, and
a collecting step for receiving particles and liquid from the vertical cylindrical separation space of the first vertical cylindrical vessel in a liquid tank of the wet scrubber, wherein the liquid tank is in fluid connection with the first lower end of the vertical cylindrical separation space of the first vertical cylindrical vessel,
said method further comprising a providing step for providing a second vertical cylindrical vessel having a second upper end and a second lower end,
by a first arranging step for arranging the second upper end of the second vertical cylindrical vessel in fluid connection with the vertically oriented venturi channel for receiving the accelerated stream of liquid- and particles-laden gas from the vertically oriented venturi channel in the second vertical cylindrical vessel,
by a second arranging step for arranging, the second vertical cylindrical vessel and the swirl generator at least partly in the cylindrical separation space of the first vertical cylindrical vessel so that the first vertical cylindrical vessel coaxially at least partly surrounds the second vertical cylindrical vessel and the swirl generator, and
by arranging the swirl generator above the liquid tank.

2. The method according to claim 1 , wherein
the swirl generator used in the swirl step has an upper axial inlet for receiving the stream of accelerated stream of liquid- and particles-laden gas, and a blade arrangement forming flow channels for converting the stream of accelerated stream of liquid- and particles-laden gas into tangential streams of liquid- and particles-laden gas, wherein the blade arrangement is symmetrical with respect to the vertical cylindrical separation space of the first vertical cylindrical vessel and wherein each flow channel leading from the upper axial inlet and terminating in a gas opening is in the form of a radial outlet for discharging a tangential stream of liquid- and particles-laden gas from the flow channel,
connecting the upper axial inlet of the swirl generator in fluid connection with the second lower end of the second vertical cylindrical vessel for receiving the stream of accelerated stream of liquid- and particles-laden gas from the second vertical cylindrical vessel,
arranging the radial outlets of the swirl generator to open up into the vertical cylindrical separation space of the first vertical cylindrical vessel,
feeding the stream of accelerated stream of liquid- and particles-laden gas from the second vertical cylindrical vessel through the upper axial inlet of the swirl generator into the swirl generator,
converting the stream of accelerated stream of liquid- and particles-laden gas in the flow channels into tangential streams of liquid- and particles-laden gas, and
discharging tangential streams of liquid- and particles-laden gas from the radial outlets of the swirl generator into the vertical cylindrical separation space of the first vertical cylindrical vessel to form said cyclonic streams liquid- and particles-laden gas in the vertical cylindrical separation space of the first vertical cylindrical vessel.

3. The method according to claim 2 , wherein
the swirl generator used in the swirl step has a top that except for the upper axial inlet is closed by means of at least one top cover.

4. The method according to claim 2 , wherein
the swirl generator used in the swirl step has an at least partly open bottom in fluid connection with the liquid tank for discharging solid particles and liquid separated in the swirl generator from the swirl generator into the liquid tank, and
discharging solid particles and liquid from the swirl generator into the liquid tank during the swirl step.

5. The method according to claim 2 , wherein
the swirl generator used in the swirl step has the blade arrangement comprising two blades each having a curved section, a first plane section having a side that is connected to the curved section, and a second plane section having a side that is connected at an angle to the first plane section, wherein flow channels being formed between said two blades, each flow channel leading from the axial inlet of the swirl generator to a radial outlet of the swirl generator.

6. The method according to claim 2 , wherein
arranging the swirl generator in the vertical cylindrical separation space of the first vertical cylindrical vessel so that a circumferential space is formed between the swirl generator and the inner wall of the vertical cylindrical separation space of the first vertical cylindrical vessel.

7. The method according to claim 1 , wherein
forming an annular space between the first vertical cylindrical vessel and the second vertical cylindrical vessel,
the swirl generator used in the swirl step has a ring-shaped configuration and comprising a plurality of guide vanes for forming said cyclonic streams of liquid- and solid laden gas of the stream of said accelerated stream of liquid- and solid laden gas, and
arranging the swirl generator in the annular space between the first vertical cylindrical vessel and the second vertical cylindrical vessel for receiving the accelerated stream of liquid- and solid laden gas from the second vertical cylindrical vessel.

8. The method according to claim 7 , wherein
arranging the swirl generator in the annular space between the first vertical cylindrical vessel and the second vertical cylindrical vessel so that a circumferential space is formed between the swirl generator and the inner wall of the vertical cylindrical separation space of the first vertical cylindrical vessel for allowing solid particles and liquid to flow past the swirl generator from a location above the swirl generator to the liquid tank below the swirl generator.

9. The method according

Assignees

• Outotec Finland Oy

Inventors

• Xia Jiliang
• Johansson Robert
• Jyrkoenen Satu
• Skilling Leif
• Gustavsson Anders
• Hedstroem Lars

Classifications

• B01D45/16

  generated by the winding course of the gas stream {, the centrifugal forces being generated solely or partly by mechanical means, e.g. fixed swirl vanes} · CPC title

• B01D2247/08

  Means for controlling the separation process · CPC title

• B01D2247/108

  using vortex inducers · CPC title

• B01D47/10 Primary

  Venturi scrubbers · CPC title

• B01D2247/101

  using a cyclone · CPC title