Method and apparatus for combusting fuel in a pulse combustor

• US 4,819,873 A
• Filed: 04/23/1987
• Issued: 04/11/1989
• Est. Priority Date: 04/16/1986
• Status: Expired due to Term

• Current Assignee: NEA Technology Transfer Corporation
• Original Assignee: Neal Technologies Incorporated
• Inventors: Lockwood, Hanford N. Jr.
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): Weldon, Kevin P.
• Application Number:
  US07/041,804
• Time in Patent Office: 719 Days
• Field of Search: 239/8, 239/9, 239/5, 239/416.1, 239/422, 239/335, 431/1, 431/18
• US Class Current: 239/8
• CPC Class Codes: F02G 1/02 of open-cycle type
• CPC Class Codes: F02G 2254/11 Catalytic burners
• CPC Class Codes: F02G 2258/10 ceramic
• CPC Class Codes: F23C 1/08 liquid and gaseous fuel
• 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: F26B 17/10 with movement performed by fluid currents, e.g. issuing from a nozzle, e.g. pneumatic, flash, vortex or entrainment dryersF26B3/08 takes precedence
• CPC Class Codes: F26B 23/026 with pulse combustion, e.g. pulse jet combustion drying of particulate materials

Abstract

A pulse combustion energy system including a pulse combustor coupled to a processing tube for flowing material to be processed therethrough, the processing tube being coupled to a pair of cyclone collectors for receiving the material flowing therefrom. An optional recycling section is coupled to the cyclone collectors for flowing vapor from the cyclone collectors back to the upstream end of the processing tube. The pulse combustor includes a rotary valve, a combustion chamber, an inner tail pipe and an outer tail pipe. The combustion chamber and inner tail pipe are conical and tubular sections mounted in longitudinal compression, and the compressive forces are transmitted externally across the junction of the combustion chamber and tail pipe by a strongback assembly. The rotary valve includes first, second, and third closely adjacent cylinders defining an interior air chamber. The cylinders having radially oriented, substantially aligned apertures which define an air intake. Air passing from the air chamber into the combustion chamber passes through an annular passage which impedes air flow from the combustion chamber toward the air chamber to a greater extent than air flow from the air chamber to the combustion chamber. Control systems regulate the product feed rate, the system firing rate, the system flow rate, and the operating frequency of the pulse combustor.

Claims

1. A method for combusting fuel in a combustion chamber of a pulse combustor comprising the steps of:

atomizing a liquid fuel with a gaeous fuel;

directing the atomized liquid fuel through a nozzle and into the combustion chamber of the pulse combustor; and

igniting the fuel.

2. The method according to claim 1 further comprising the step of flowing air into the combustion chamber prior to ignition of the fuel for forming a fuel-rich mixture of fuel and air in the combustion chamber.

3. The method according to claim 1 further comprising the step of flowing air into the combustion chamber prior to ignition of the fuel for forming a fuel-lean mixture of fuel and air in the combustion chamber.

4. The method according to claim 1 further comprising the step of flowing air into the combustion chamber prior to ignition of the fuel for forming a stoichiometric mixture of fuel and air in the combustion chamber.

5. A method for combusting fuel in a combustion chamber of a pulse combustor comprising the steps of:

directing a gaseous fuel through a nozzle and into the combustion chamber;

igniting the gaseous fuel;

atomizing a liquid fuel with the gaseous fuel;

directing the gaseous fuel atomized liquid fuel through the nozzle and into the combustion chamber;

igniting the gaseous fuel atomized liquid fuel;

atomizing the liquid fuel with air;

directing the air-atomized liquid fuel through the nozzle and into the combustion chamber; and

igniting the air-atomized liquid fuel.

6. The method according to claim 5 wherein the steps are performed in sequence.

7. A fuel system for a pulse combustor comprising:

a first nozzle in fluid communicating with a combustion chamber of the pulse combustor for flowing a fuel into the combustion chamber;

means, in fluid communication with the nozzle, for selectively flowing a gaseous fuel through the nozzle;

means for selectively atomizing a liquid fuel with a gas, the gas being one of either the gaseous fuel or air; and

means, in fluid communication with the atomizing means and with the first nozzle, for selectively flowing the gas-atomized liquid fuel through the nozzle;

so that the fuel flowing through the nozzle and into the combustion chamber selectively comprises gaseous fuel, gaseous-fuel-atomized liquid fuel, or air-atomized liquid fuel.

8. The fuel system according to claim 7 further comprising second nozzle, in fluid communication with the flowing means and with the combustion chamber, for selectively flowing one of the gaseous feul, the gaseous-fuel-atomized liquid fuel, or the air-atomized liquid fuel into the combustion chamber.

9. The fuel system according to claim 8 wherein the flowing means flows one of the gaseous fuel, the gaseous-fuel-atomized liquid fuel, or the air-atomized liquid fuel through the first nozzle and into the combustion chamber, and wherein the flowing means simultaneously flows a different one of the gaseous fuel, the gaseous-fuel-atomized liquid fuel, or the air-atomized liquid fuel through the second nozzle and into the combustion chamber.

10. A fuel system for a pulse combustor comprising:

a nozzle in fluid communication with a combustion chamber of the pulse combustor;

a source of liquid fuel and a source of gaseous fuel

means for atomizing the liquid fuel with the gas;

means, coupled to the nozzle and to the atomizing means, for flowing the gas-atomized liquid fuel through the first nozzle and into the combustion chamber.

11. A method for combusting fuel in a combustion chamber of a pulse combustor comprising the steps of:

atomizing a liquid fuel with a gaseous fuel;

discharging the gas-atomized liquid fuel into the combustion chamber;

igniting the gas-atomized liquid fuel for creating self-sustaining combustion pulses having a selected high frequency and for creating a hot combustion chamber; and

wherein the hot combustion chamber initiates burning between the gas and the liquid fuel as the gas-atomized liquid fuel is discharged into the hot combustion chamber.

12. In a pulse combustor wherein fuel is discharged into and detonated in a hot combustion chamber for creating self-sustaining, high-frequency combustion pulses, the fuel ordinarily being detonated at a prescribed time after the fuel is discharged into the combustion chamber, a method of initiating detonation of the fuel at a time earlier than the prescribed time comprising the steps of:

a source of liquid fuel and a source of gaseous fuel

atomizing the liquid fuel with the gas;

discharging the gas-atomized liquid fuel into the hot combustion chamber; and

wherein the hot combustion chamber initiates detonation between the atomizing gas and the liquid fuel as the gas-atomized liquid fuel is discharged into the hot combustion chamber, and at a time earlier than the prescribed time.