Pulse combusted acoustic agglomeration apparatus and process

• US 5,353,721 A
• Filed: 03/29/1993
• Issued: 10/11/1994
• Est. Priority Date: 07/15/1991
• Status: Expired due to Term

• Current Assignee: Manufacturing and Technology Conversion International Incorporated
• Original Assignee: Manufacturing and Technology Conversion International Incorporated
• Inventors: Chandran, Ravi, Mansour, Momtaz N.
• Primary Examiner(s): Favors, Edward G.
• Application Number:
  US08/041,213
• Time in Patent Office: 561 Days
• Field of Search: 110/216, 110/345, 110/344, 110/347, 110/212, 110/266, 431/1, 122/24, 66/39.38, 66/39.76, 66/39.77, 422/182
• US Class Current: 110/345
• CPC Class Codes: B01D 45/12 by centrifugal forces centrifuges B04B; cyclones B04C
• CPC Class Codes: B01D 49/006 by sonic or ultrasonic techniques
• CPC Class Codes: B01D 51/08 by sound or ultrasonics
• CPC Class Codes: F01D 25/002 Cleaning of turbomachines
• CPC Class Codes: F01D 25/007 Preventing corrosion
• CPC Class Codes: F02C 7/30 Preventing corrosion or unwanted deposits in gas-swept spaces
• CPC Class Codes: F02K 7/04 with resonant combustion chambers
• CPC Class Codes: F23C 15/00 Apparatus in which combustion takes place in pulses influenced by acoustic resonance in a gas mass for generating combustion products of high pressure or high velocity F23R7/00; starting devices F23D11/42
• CPC Class Codes: F23J 15/00 Arrangements of devices for treating smoke or fumes
• CPC Class Codes: F23J 15/02 of purifiers, e.g. for removing noxious material traps for solid residues F23J3/04

Abstract

An improved apparatus and process for removal of particulates entrained in a gas stream are provided. The removal process employs a pulse combustor to provide an acoustic pressure wave to acoustically enhance agglomeration of particulates which may be collected and removed using a conventional separation apparatus. The apparatus may be employed as a direct fired system for improved operation of gas-operated equipment such as a gas turbine, or may, alternatively, be employed as an add-on subsystem for combustion exhaust clean-up. Additionally, added particulates may include a sorbent for effecting sorption of other contaminants such as sulfur. Various other particulates for contaminant removal may also be introduced into the system as exemplified by alkali-gettering agents.

Claims

1. Improved apparatus for removal of particulates entrained in a gas stream comprising:

means for receiving a gas stream having particulates therein and for allowing passage of said gas stream therethrough;

pulse combustor means in communication with said gas stream receiving means for producing a pulsating stream of hot combustion products and an acoustic wave having a frequency within the range of from about 20 to about 1500 Hz which acts on said gas stream so that acoustically-enhanced agglomeration of particulate materials entrained in said gas stream occurs permitting enhanced removal of said agglomerated particulate materials.

2. Apparatus as defined in claim 1 wherein said pulse combustor means is located within said gas stream receiving means.

3. Apparatus as defined in claim 2 wherein said pulse combustor means comprises a combustion chamber, fuel valve means in communication with said combustion chamber and a resonance tube in communication with said combustor chamber and having an exit within said gas stream receiving means and wherein said resonance tube exit is located approximately in the center of said gas stream receiving means.

4. Apparatus as defined in claim 1 further comprising means for removing said agglomerates from said gas stream.

5. Apparatus as defined in claim 4 wherein said removal means is a cyclone.

6. Apparatus as defined in claim 5 wherein said cyclone is heated.

7. Apparatus as defined in claim 3 wherein said gas stream receiving means comprises two distinct sections wherein at least one of said sections comprises an annulus about said resonance tube.

21. The apparatus as defined in claim 3 further comprising means for injecting fuel into said fuel valve means.

22. The apparatus as defined in claim 3 further comprising a water jacket about said combustion chamber is water jacketed to allow circulation of cooling liquid about said combustion chamber.

23. The apparatus as defined in claim 7 wherein said resonance tube is approximately one-half the length of said annulus.

24. The apparatus as defined in claim 23 further comprising a second about said annulus.

25. The apparatus as defined in claim 24 further comprising a sound reflector arranged in a traversing location relative to said second annulus so that said pulse combustor means may be tuned to achieve a standing wave in said annulus and said second annulus so that the acoustic loss from said pulse combustor means is reduced.

26. The apparatus as defined in claim 1 further comprising a means for introducing humidity into said apparatus to particulate removal.

27. The apparatus as defined in claim 26 wherein said humidification introduction means comprises a water spray port located relative to said pulse combustor means to allow said humidity to act directly on said pulsating stream of hot combustion products.

8. Improved process for removal of particulates from a gaseous stream comprising the steps of

bringing a gas stream having particulates entrained therein under the influence of a pulse combusted acoustic pressure wave at a frequency in a range of from about 20 to about 1500 Hz to effectuate acoustic enhanced particulate agglomeration.

9. A process as defined in claim 8 wherein said pulse combusted acoustic pressure wave accompanies a hot combustion product stream which contains particulate matter to be agglomerated and is merged with a further gas stream in which other particulates are entrained.

10. A process as defined in claim 8 further comprising the step of removing said agglomerates to effectuate enhanced cleaning of said gaseous stream.

11. A process as defined in claim 9 further comprising the step of removing said agglomerates to effectuate enhanced cleaning of said gaseous stream.

12. A process as defined in claim 8 wherein a particulate fuel-air mixture is pulse combusted.

13. A process as defined in claim 8 wherein said particulate in said gas stream is fly ash produced by the combustion of coal.

14. A process as defined in claim 8 wherein said acoustic pressure wave has a frequency within a range of from about 50 to about 250 Hz.

15. A process as defined in claim 8 wherein the heat produced by said pulse combustion has a temperature less than the temperature at which said particulates in the streams begin to form slag.

16. A process as defined in claim 8 wherein said gas stream which has been cleaned is provided to a device employing a gas stream for operation thereof.

17. A process as defined in claim 16 wherein said device employing a gas stream for operation thereof is a turbine.

18. A process as defined in claim 8 wherein heat produced during said process is maintained in a range of from 1 MMBtu/hr to about 6 MMBtu/hr.

19. A process as defined in claim 8 wherein the gas stream containing the particulate is a hot pulse combustion product stream that is accompanied by said pressure wave.

29. A process as defined in claim 8 further comprising the step of introducing humidity into said particulate gas stream.

30. A process as defined in claim 13 wherein humidity is added to said hot combustion product stream.

31. A process as defined in claim 13 wherein said acoustic pressure wave accompanies said hot combustion product stream.

32. A process as defined in claim 30 wherein a sorbent is added to said hot combustion product stream to capture contaminents wherein said sorbent is selected from the group consisting of limestone, dolomite, lime, and hydrated lime.

33. A process as defined in claim 32 wherein said contaminents captured by said sorbent include sulphur derivatives.

34. A process as defined in claim 30 wherein an alkali-gettering agent is added to said hot combustion production stream and wherein said alkali-gettering agent is selected from the group consisting of diatomaceous earth, emathlite, silica, bauxite, vermiculite, hectorite, and kaolin.

35. A process as defined in claim 30 wherein said gas stream remains hot during removal of said particulates therefrom.

20. Improved process for removal of particulates from a gaseous stream comprising the steps of:

pulse combusting a fuel to produce a hot combustion product stream and an acoustic pressure wave at a frequency in a range of from about 20 to about 1500 Hz;

merging said product stream and pressure wave with an independent gas stream having particulates entrained therein so that acoustically enhanced particulate agglomeration occurs removing said particulate agglomerates from said merged streams; and

thereafter providing said merged gas streams for operation of downstream equipment.

28. Improved apparatus for removal of particulates entrained in a gas stream comprising:

a) means for receiving a gas stream having particulates therein and for allowing passage of said gas stream therethrough;

b) pulse combustor means comprising a combustion chamber, fuel valve means in communication with said combustion chamber, and a resonance tube in communication with said combustion chamber and having an exit within said gas stream receiving means and wherein said pulse combustor means is in communication with said gas stream receiving means for producing a pulsating stream of hot combustion products and an acoustic wave that acts on said gas stream so that acoustically-enhanced agglomeration of particulate materials entrained in said gas stream occurs, thus permitting enhanced removal of said agglomerated particulate materials;

c) means for injecting sulfur capturing sorbents into said stream of hot combustion products; and

d) means for introducing humidity to said apparatus to act on said hot combustion products to enhance sulfur capture and removal of said particulates.

36. Improved process for removal of particulates from a gaseous stream comprising the steps of:

a) pulse combusting a fuel to produce a hot combustion product stream and an acoustic pressure wave;

b) allowing said hot combustion product stream to act on said particulate gaseous stream; and

c) introducing moisture into said hot combustion product stream to enhance said removal of particulates.

37. A process as defined in claim 36 further comprising the step of introducing a sorbent to said hot combustion product stream.