Arrangement and method in electric filter

Patent metadata

Field	Value
Publication number	US-9845952-B2
Application number	US-201314410646-A
Country	US
Kind code	B2
Filing date	Jun 26, 2013
Priority date	Jun 28, 2012
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

An arrangement and method in connection with an electric filter of a boiler plant, the electric filter comprising an insulator chamber. The arrangement comprises a first scavenging duct for conveying warm scavenging gas to the insulator chamber. Said first scavenging duct is connected to a channel conveying process gas in the boiler plant, which means that it is possible to supply process gas to the insulator chamber.

First claim

The invention claimed is:

1. An electric filter of a boiler plant, the electric filter comprising:
an insulator chamber, and
a first scavenging duct for conveying warm scavenging gas to the insulator chamber,
said first scavenging duct being connected to a channel conveying process gas in the boiler plant such that the process gas is supplied to the insulator chamber as the warm scavenging gas,
said process gas being secondary, tertiary, or some other corresponding air of the boiler plant.

2. The electric filter as claimed in claim 1 , wherein the boiler plant is one of the following:
a soda recovery boiler,
a bubbling fluidized-bed boiler,
a circulating fluidized-bed boiler,
a gas plant,
a pyrolysis plant, and
a grate boiler.

3. The electric filter as claimed in claim 1 , wherein the temperature of the process gas is in the range of 80° to 300° C.

4. The electric filter as claimed in claim 2 , wherein the temperature of the process gas is in the range of 80° to 300° C.

5. The electric filter of claim 1 , further comprising:
a heating device, and
a second scavenging duct that is connected between the heating device and the insulator chamber, whereby gas heated by the heating device is supplied to the insulator chamber as scavenging gas,
the second scavenging duct being connected to the insulator chamber through a valve arrangement arranged to open and close the second scavenging duct.

6. The electric filter as claimed in claim 5 , wherein the valve arrangement comprises:
a three-way valve arranged in the first scavenging duct with a third connection being connected to the second scavenging duct, and
the valve arrangement further comprises control means for controlling said three-way valve and for changing the scavenging gas supply from the first scavenging duct to the second scavenging duct and vice versa.

7. A method for supplying scavenger gas to an insulator chamber of an electric filter of a boiler plant, the method comprising:
conveying warm scavenging gas from a first scavenging duct to the insulator chamber,
wherein process gas of the boiler plant is used as the scavenging gas, and
wherein the process gas is a secondary, tertiary, or some other corresponding air of the boiler plant.

8. The method of claim 7 , wherein the process gas used as the scavenging gas is from one of the following boiler plants:
a soda recovery boiler,
a bubbling fluidized-bed boiler,
a circulating fluidized-bed boiler,
a gas plant,
a pyrolysis plant, and
a grate boiler.

9. The method of claim 7 , wherein the scavenging gas is conveyed to the insulator chamber at a temperature in the range of 80° to 300° C.

10. The method of claim 8 , wherein the scavenging gas is conveyed to the insulator chamber at a temperature in the range of 80° to 300° C.

11. The method of claim 7 , further comprising
feeding scavenging gas to the insulator chamber through a heating device and a second scavenging duct during a start-up phase of the boiler plant, and
after the boiler plant reaches normal operation, feeding process gas of the boiler plant as the scavenging gas to the insulator chamber.

12. The method of claim 11 , further comprising
conveying the scavenging gas to the insulator chamber through a three-way valve arranged in the first scavenging duct with a third connection being connected to the second scavenging duct, and
controlling said three-way valve to change the scavenging air supply from the first scavenging duct to the second scavenging duct and vice versa.

Assignees

• Valmet Technologies Oy

Inventors

• Tolvanen Juha

Classifications

• B03C3/70 Primary

  insulating in electric separators (B03C3/53 takes precedence) · CPC title

• B03C3/017

  Combinations of electrostatic separation with other processes, not otherwise provided for · CPC title

• B03C3/80

  by gas or solid particle blasting · CPC title

• F23J15/025 Primary

  using filters · CPC title

• B03C3/34

  Constructional details or accessories or operation thereof · CPC title