PULSE COMBUSTOR SYSTEM FOR GAS FLARE STACK REPLACEMENT

SYSTEME DE COMBUSTION PULSEE POUR REMPLACER UNE TORCHERE

English Abstract

The invention provides a unique, detailed method of burning gaseous fuels
from oil/ gas fields or landfills replacing existing gas flare stack systems.
The invention mainly consists of an aerovalved pulse-combustor that
promote the flow of air and hot combustion gases to a swirl-combustor that
burn more fuel in the system. A photovoltaic solar system or a
thermoelectric system produces electricity that charges a small battery that
supplies energy to an ignition system. The electrical power is also used to
drive an electrical motor that drives a small compressor that keeps an air
pressurized tank full. Both the ignition and compressed air are only briefly
active at the beginning of the ignition phase of the system. The only
moving part is the electrical-motor compressor that is only activated when
the air tank is not full.

Claims

CLAIMS:
I claim:
1. The use of a pulse combustor device as a basic incinerator of gaseous fuels
from
oil/gas fields or landfills. This pulse combustor incinerator replaces
existing gas flare
stacks for these applications.
2. The use of a pulse combustor as described on item 1 in conjunction with a
more
conventional combustor such as a swirl burner. The pulse combustor is used to
crete a
flow of burned gases and induced air, through an ejector to the swirl
combustor.
3. The use of a pulse combustor as described on item 1 that uses compressed
air
coming from a tank that is used to assist the pulse combustor starting
operation.
4. The whole system as shown in Fig I where the pulse combustor pumps hot
gases/
air to the steady flow combustor using an auxiliary starting system that
consists
mainly of a compressed air tank and an ignition device.
5. A method of obtaining high combustion performace with the use of a pulse
combustor to pump air to a secondary combustor, eliminating or reducing the
need for
a combustion fan. This system can be used in pressurized combustion such as in
gas
turbine engines.

Description

nw
CA 02450485 2003-11-17
- PAGE 3-
Pulse Combustor System For Gas Flare Stack Replacement
This invention is a combustion device that burns gaseous fuel in an efficient
an
simple way replacing existing gas flare stack systems.
BACKGROUND:
In oil and gas fields as well as landfills it is common to burn gaseous fuel
using
flare stacks. This flare stacks have the flame burning in an open field
subject to
cross winds. The efficient of gas flare stacks can severely deteriorate
pending on
is atmospheric conditions and in special the wind velocity. The gas and air
mixes
mainly at the stack tip and the consequently burning efficiencies varies
depending
on the degree of mixing between the fuel and air. On the other hand,
conventional
incinerators used to replace flare stacks use buoyant forces to promote air
movement and therefore use long chimneys to promote the necessary draft. These
2o incinerators are expensive and bulky.
The proposed system uses a pulse combustor that burns some of the gasous fuel
producing a flow of hot combustion gases that induces external air in to its
strain.
These mixture of gases and air flows to a swirl combustor that burns the
reamaining gaseos fuel. The use of the pulse combustor eliminates the need of
chimneys used in conventional incinerators creating a much more compact and
efficient burning system. To avoid overloading the pulse combustor, which can
produce significant amounts of acoustic noise plus high combustor parts
temperatures, the system uses a swirl combustor in series that can burn the
remaining raw gaseous fuel.


y,
CA 02450485 2003-11-17
- PAGE 4-
An auxiliary starting system, consisiting mainly of an electrical ignitor plus
compressed air is used to initiate the pulse combustor operation. This
auxiliary
starting system is only activated at the beginning of the pulse combusto
ignition
phase. Once the pulse combustor starts its operational cycle, there is no need
for
either external ignition sources or auxiliary compressed air.
SUMMARY OF THE INVENTION:
It is the object of the present invention to provide an extremely simple way
of
15 burning gaseous fuel from oil/ gas fields or landfills in replace of gas
flare stacks or
incinerators.
The present invention accomplishes these objectives using, as shown on Fig l,
an
air tank 1 that has an air compressor 2 that compressses atmospheric air
supplying
20 it during the starting phase of a pulse combustor 3. At the pulse combustor
exit and
air ejector 4 guarantees new fresh air necessary to flow into the swirl
cornbustor
case 5 whey it mixes with fuel at the swirl combustor tube 6. The swirl
combustor
6 is used here to burn more fuel avoiding overloading the pulse combustor with
fuel and, if necessary, it can burn with flame at higher temperatures. This is
25 because the pulse combustor 3 tend to both increase noise and combustor
wall
temperatures with the increase of fuel being burned.
For starting conditions, a solar collector 7 is suggested as a source of
electricity but
it could have been a thermoelectric device using the hot combustor wall energy
associated. The electricity produced in 7 is used to charge a small battery 10
that is
used to produce electrical power to activate the ignition system. Therefore,
the
electrical energy source 7 also drives the small compressor 1. The control
system
11 guarantees that when gasous fine is coming to the system, it activates both
the
ignition and compressed air system. The ignition and compressed air are used
to
start the pulse combustor. Both devices can also used to assist to start the
swirl
4


CA 02450485 2003-11-17
y
- PAGE S-
combustor operation. Once the pulse combustor operates in its natural
frequency,
there is no need for external supply or ignition source. Alternatively the
electrical generator 7 could be a simple turbine located at the air ejector
region 4
driving a small generator plus the compressor 2.

Representative Drawing