U.S. patent application number 14/513496 was filed with the patent office on 2015-04-23 for biomass gasifier system for power generation.
The applicant listed for this patent is KRISHNA KUMAR BINDINGNAVALE RANGA. Invention is credited to KRISHNA KUMAR BINDINGNAVALE RANGA.
Application Number | 20150107496 14/513496 |
Document ID | / |
Family ID | 52825048 |
Filed Date | 2015-04-23 |
United States Patent
Application |
20150107496 |
Kind Code |
A1 |
BINDINGNAVALE RANGA; KRISHNA
KUMAR |
April 23, 2015 |
BIOMASS GASIFIER SYSTEM FOR POWER GENERATION
Abstract
The various embodiments herein provide an improved biomass based
down draft gasifier for producing electrical energy. The gasifier
comprises a reactor with double walled construction having an
annular space between outer and inner shells. The annular space
houses multiple helical guide vanes welded to the inner shell. The
reactor is covered with a top cover assembly. An air inlet manifold
is provided for directing the controlled air into the reactor
through the air inlet nozzles. An automatic start system is
provided for controlling the combustion of inlet fuel done with a
spark plug. The gasifier comprises a throat which permits the ashes
and charcoal of burnt fuel to drop into the bottom of the reactor.
The gas separation holes are provided at the bottom of the reactor
to separate the product gas from the charcoal. The product gas is
taken out from an output pipe.
Inventors: |
BINDINGNAVALE RANGA; KRISHNA
KUMAR; (BANGALORE, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BINDINGNAVALE RANGA; KRISHNA KUMAR |
BANGALORE |
|
IN |
|
|
Family ID: |
52825048 |
Appl. No.: |
14/513496 |
Filed: |
October 14, 2014 |
Current U.S.
Class: |
110/185 ;
110/203; 110/232 |
Current CPC
Class: |
F23G 7/10 20130101; F23G
2207/30 20130101; Y02E 20/12 20130101; F23G 5/0276 20130101; F23G
5/46 20130101; F23G 2900/7012 20130101; F23M 9/08 20130101; F23G
5/04 20130101; F23G 2206/203 20130101; F23G 2201/303 20130101; F23G
2202/103 20130101; F23G 2209/262 20130101; F23G 2206/10 20130101;
F23G 2900/50002 20130101; F23G 2202/101 20130101; F23G 2209/261
20130101 |
Class at
Publication: |
110/185 ;
110/203; 110/232 |
International
Class: |
F23K 1/00 20060101
F23K001/00; F23J 11/00 20060101 F23J011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 18, 2013 |
IN |
1722/CHE/2013 |
Claims
1. A down draft gasifier for generating energy comprising: a
reactor assembly comprising an inner shell, an outer shell, a
helical guide vane, and an output pipe, and wherein the reactor is
a double walled construction, and wherein the reactor is loaded
with a solid fuel, and wherein the reactor is configured to smolder
a solid fuel to produce a product gas, wherein the product gas is
used to generate a required energy and wherein the helical guide
vane is configured to assist a uniform flow of the product gas
around an outer peripheral surface of the inner shell, and wherein
the output pipe is mounted at extreme top end of the outer shell to
eject the product gas yielded from the reactor; a top cover
assembly arranged on the top of the reactor, configured to provide
protection to surrounding environment from any hazardous situations
created in the reactor; an air inlet assembly configured for
directing a controlled air into a combustion zone of the reactor
through a set of air inlet nozzles, wherein the air is used for
combustion of the solid fuel to produce the product gas; an
automatic start unit configured to control the combustion of the
inlet solid fuel; a stirrer assembly configured to break the solid
fuel into lumps for enabling the stable gas flow, and a support
system configured to sustain a weight of the reactor assembly.
2. The system according to claim 1, wherein the top cover assembly
is a spring loaded top cover which automatically opens during an
overpressure or an explosion inside the reactor, wherein the top
cover assembly is fastened to a top flange of the reactor using a
plurality of bolts, wherein the top cover assembly is fastened in a
circular manner so as to seal the top of reactor.
3. The system according to claim 1, wherein the air inlet assembly
comprises an air inlet manifold provided at the outer surface of
the outer shell, wherein the air inlet manifold is configured to
supply the air required for combustion of the fuel inside the
reactor through a plurality of air inlet nozzles, wherein the
plurality of air inlet nozzles are configured to control a quantum
of air into the reactor chamber and facilitate a quick replacement
in case of corrosion.
4. The system according to claim 1, wherein the air inlet nozzle is
adjustable to penetrate inside the reactor by a required distance
before an initiation of the reactor, and wherein the air inlet
nozzle is inserted into an outer pipe, and wherein the outer pipe
is welded with the inner shell and housed inside a gland.
5. The system according to claim 1, wherein the gland allows a free
thermal expansion of the air inlet nozzle and avoids a formation of
crack on the output pipe due to stress, heat and a differential
growth between the inner shell and the outer shell of the
reactor.
6. The system according to claim 1, further comprises an angular
space between the outer shell and the inner shell of the reactor,
wherein the angular space houses the helical guide vane, wherein
the helical guide vane is welded to the inner shell of the
reactor.
7. The system according to claim 1, wherein the helical guide vane
is in arranged in a form of a multi strand thread to guide the
product gas to flow in a helical pattern around the inner shell,
wherein the helical guide vane increases a residence time of the
product gas inside the annular space and causes a heat transfer
from the product gas to the surroundings inner shell.
8. The system according to claim 1, further provides a gap of
predetermined size between the inner surface of the outer shell and
the helical guide vanes, wherein the gap is configured to freely
drop down to ash and other solid condensable contaminants to the
bottom of the reactor.
9. The system according to claim 1, wherein the automatic start
system comprises a Liquefied Petroleum Gas (LPG) fuel line
connected to a burner assembly, wherein the LPG is ignited by a
built-in spark plug.
10. The system according to claim 1, further comprises a digital
control system such as a Programmable Logic Circuits (PLC) for
controlling the inlet of LPG and ignition of the spark plug,
wherein a control valve is provided to operate a start and stop of
combustion process, wherein the control valve is commanded by the
digital control system.
11. The system according to claim 1, further comprises a suction
blower configured to apply suction at the outer pipe, wherein the
suction draws the air from the burner and preheats the air to a
predetermined temperature.
12. The system according to claim 1, further comprises a lifting
bracket configured to lift and place the gasifier from one location
to another location, wherein the lifting bracket is welded to the
outer surface of the outer shell.
13. The system according to claim 1, further comprises a hearth
provided to support the fuel under combustion and permits a pile of
glowing charcoal underneath, wherein the charcoal filters the
product gas by breaking down the tar into combustible
compounds.
14. The system according to claim 1, further comprises a plurality
of radial gas separation holes provided in the wall of the inner
shell of the reactor, wherein the holes are configured to separate
the product gas from the charcoal, wherein the holes block the
charcoal and permit only the product gas to exit from the inner
shell to the annular space.
15. The system according to claim 1, wherein the stirrer assembly
comprises a stirrer configured to stir the glowing charcoal bed so
as to prevent blockages leading obstruction of gas flow, wherein
the stirrer is driven by a gear box connected to a motor, wherein
the stirrer is rotated by the motor, wherein the stirrer shaft
passes through a plurality of glands and enters the bottom of the
reactor.
16. The system according to claim 1, further comprises an ash
removal funnel placed in the annular space between the inner shell
and the outer shell, wherein the ash removal funnel is mounted on
an ash removal flange, wherein the ash removal funnel collects the
ash dropped to the bottom of the reactor and the collected ash is
taken out by the ash removal flange.
17. The system according to claim 1, wherein the support system
comprises a plurality of support brackets, wherein the support
brackets are sustained by a plurality of stands configured to
support the reactor system.
18. The system according to claim 1, further comprises a gas blower
attached to the reactor which enhances a start performance and
transient response to the load changes, wherein a cyclonic
separator is configured to enhance the purity of gas by reducing
contamination load on water scrubber and preventing the clogging of
water scrubber.
19. The system according to claim 1, further comprises an infrared
laser beam configured to detect and indicate the level of fuel
consumption inside the reactor.
20. The system according to claim 1, comprises a safety unit
configured to automatically shutting down the reactor for a variety
of out-of-limit operating parameters, wherein the parameters
include a high reactor pressure, a high reactor temperature, a high
water temperature, a low water level, a water pump failure, a low
frequency, a high frequency, a gas leakage.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the priority of the Indian
Provisional Patent Application No. 1722/CHFJ2013 filed on Apr. 18,
2013, and postdated to Oct. 18, 2013 with the title "An Improved
Biomass Gasifier System for Power Generation", and the content of
which is incorporated in entirety by reference herein.
BACKGROUND
[0002] 1. Technical Field
[0003] The embodiments herein generally relate to the electrical
power generation systems and particularly relates to a system and
method for generating an electrical power through biomass. The
embodiments herein more particularly relates to a method and a
system for generating an electrical power using an efficient and
improved down draft biomass gasifier with an Internal Combustion
(IC) engine coupled to an electrical generator.
[0004] 2. Description of the Related Art
[0005] Biomass gasifiers have been extant for many years and are
manufactured in many countries by many manufacturers. Wood-based
gasifiers were extensively used during the Second World War period
(1939-1945) in Europe and elsewhere, to provide fuel gas for the
petrol-engine based vehicles and electrical generators. There are
principally two types of gasifiers, known as an up-draft gasifier
and a down draft gasifier. The down draft gasifier is preferred for
the IC engine applications, as the generated gas is relatively free
of tar. The electrical generators equipped with gasifier have been
manufactured in India for several years. They are mainly of the
down draft type, and are coupled to the electrical generators
equipped with IC engine.
[0006] The existing down draft type gasifier uses mild steel/carbon
steel for the construction of reactor chamber walls. The usage of
mild steel provides a short lifespan of around four to five years
for the gasifiers. These gasifiers required a refractory lining to
protect the mild steel from oxidation, which increases the
maintenance and initial cost. Further the temperature of the output
gases coming out of the output pipe is high and is in the range of
400-6000 C, which further needs to be cooled down by water. The
volume of water commonly required for cooling the output gas is
considerable. The gasifiers also have a welded bottom surface
thereby providing difficulty in the cleaning and maintenance of the
gasifiers. The gasifier needs to be inverted and then cleaned.
Further, the existing literature does not discuss about a removal
bottom and providing a stirrer.
[0007] Though, the existing down draft gasifiers have been used
continuously, there are various drawbacks leading to an inefficient
operation. The drawbacks include a continuous requirement of an
operator throughout the day and night due to a lack of automated
monitoring system and process. Further, a starting and stopping of
the gasifier requires a laborious and dangerous process of manually
lighting the gasifier using a burning torch, while managing several
control valves. Also, in the existing gasifiers, a tar condensation
inside the feed-hopper leads to a fuel clogging. Hence an extra
vibrator is used to ensure a smooth feeding of the fuel. Other
limitations of the existing gasifiers are clogging of scrub-water
circuit with carry-over sediment and failure of stirring system at
the bottom of the gasifier due to clogging.
[0008] Hence, there is a need for an improved and efficient
gasifier system for generating electric power. Also there is a need
for a method and system for automatically starting and stopping the
gasifier based on running condition. Further, there is a need for a
gasifier with simple construction to provide ease of usage and
maintenance. Still further, there is need for a method for remotely
monitoring the operations of a gasifier.
OBJECTIVES OF THE EMBODIMENTS
[0009] The primary object of the embodiments herein is to provide
an improved and efficient down draft gasifier for generating the
electrical energy.
[0010] Another object of the embodiments herein is to provide a
method and system for remotely monitoring an operation of the down
draft gasifiers.
[0011] Yet another object of the embodiments herein is to decrease
temperature of output gas to an optimum level within the material
limits of constructional parts of the down draft gasifier.
[0012] Yet another object of embodiments herein is to provide a
system with a controlled air inlet to the reactor chamber of the
down draft gasifier for a proper smoldering process.
[0013] Yet another object of the embodiments herein is to provide a
system for remotely controlling the ignition and combustion process
of the fuel with automatic, user friendly and nonhazardous
operations.
[0014] Yet another object of the embodiments herein is to provide
gasifier with a simple, adjustable and flexible construction
facilitating ease of handling and maintenance.
[0015] Yet another object of the embodiments herein is to provide a
gasifier with a helical guide for output gas flow to preheat the
fuel thereby utilizing the heat of the output gas.
[0016] Yet another object of the embodiments herein is to provide a
gasifier with an automatic start, run and shutdown operations using
the state of art Programmable Logic controllers (PLC).
[0017] Yet another object of the embodiments herein is to provide a
gasifier with safety trips to safely shut down the system
automatically for a variety of out-of-limit operating parameters,
including high reactor pressure, high reactor temperature, high
water temperature, low water level, water pump failure, low
frequency, high frequency, gas leakage, etc.
[0018] Yet another object of the embodiments herein is to provide a
gasifier with an enhanced remote monitoring facility to minimize a
manpower required, to allow a health parameter trending and failure
prevention, to enhance uptime and to permit a system-wide
management.
[0019] Yet another object of the embodiments herein is to provide a
gasifier with a Polished Stainless Steel construction to provide a
superior aesthetics design, corrosion and erosion resistant
properties, negligible maintenance, extended life and smoother fuel
feeding operation.
[0020] Yet another object of the embodiments herein is to provide a
gasifier with a straight cylindrical design to improve fuel feeding
operation, to prevent clogging and to eliminate a requirement for
the vibrator.
[0021] Yet another object of the embodiments herein is to provide a
gasifier with a double walled construction with gas flow in an
annular region to provide an extended residence time for the output
gas to encourage a drop-out of the particulates into an ash removal
chute, to transfer the heat from the output gas to the fuel in the
feed hopper to reduce a moisture content, to heat hopper inner wall
to prevent condensation of tar and adhesion of wood chunks to the
wall, to reduce the temperature of output gas, to minimizing water
consumption, and to provide a higher efficiency due to a capture of
heat in output gas back into the input fuel.
[0022] Yet another object of the embodiments herein is to provide a
gasifier with a scrub-water cooling technology by radiator to
eliminate spray-cooling, to reduce attendant water losses, and to
minimize cooling water requirement.
[0023] Yet another object of the embodiments herein is to provide a
gasifier with additional gas blowers and cyclonic separators to
enhance a transient response with respect to load changes, to
enhance purity of gas, to reduce a contamination load on water
scrubber and to prevent clogging of venturi scrubber.
[0024] These and other objects and advantages of the embodiments
herein will become readily apparent from the following detailed
description taken in conjunction with the accompanying
drawings.
SUMMARY
[0025] The embodiments herein provide a down draft gasifier for
generating energy. The gasifier comprises a reactor, a top cover
assembly, an air inlet assembly, an automatic start unit, a stirrer
assembly and a support system. The reactor is configured to smolder
solid fuel to produce a product gas. The product gas is used to
generate required energy. The top cover assembly arranged on top of
the reactor is configured to provide protection to surrounding
environment from any hazardous situations created in the reactor.
The air inlet assembly is configured for directing a controlled air
into a combustion zone of the reactor through a set of air inlet
nozzles. The air is used for combustion of the solid fuel to
produce the product gas. The automatic start unit is configured to
control the combustion of the inlet solid fuel. The stirrer
assembly configured to break the solid fuel into lumps for enabling
the stable gas flow. The support system configured to sustain
weight of the reactor assembly. The reactor is loaded with a solid
fuel. The reactor is a double walled construction comprising an
inner shell and an outer shell. The reactor further comprises a
helical guide vane configured to assist a uniform flow of the
product gas around the outer peripheral surface of the inner shell.
The system comprises an output pipe mounted at extreme top end of
the outer shell is configured to eject the product gas yielded from
the reactor.
[0026] According to one embodiment herein, the top cover assembly
is a spring loaded top cover which automatically opens during an
overpressure or an explosion inside the reactor. The top cover
assembly is fastened to a top flange of the reactor using a
plurality of bolts. The top cover assembly is fastened in a
circular manner so as to seal the top of reactor.
[0027] According to one embodiment herein, the air inlet assembly
comprises an air inlet manifold provided at the outer surface of
the outer shell. The air inlet manifold is configured to supply the
air required for combustion of the fuel inside the reactor through
a plurality of air inlet nozzles. The plurality of air inlet
nozzles is configured to control the quantum of air into the
reactor chamber and facilitate a quick replacement in case of
corrosion.
[0028] According to one embodiment herein, the air inlet nozzle is
adjustable to a required penetration inside the reactor before an
initiation of the reactor. The air inlet nozzle is inserted into an
outer pipe. The outer pipe is welded with the inner shell and
housed inside a gland.
[0029] According to one embodiment herein, the gland allows a free
thermal expansion of the air inlet nozzle and avoids formation of
crack on the output pipe due to stress, heat and differential
growth between the inner shell and the outer shell of the
reactor.
[0030] According to one embodiment herein, the system further
comprises an angular space between the outer shell and the inner
shell of the reactor. The angular space houses the helical guide
vanes which are welded to the inner shell of the reactor.
[0031] According to one embodiment herein, the helical guide vane
is in the form of a multi strand thread to guide the product gas to
flow in a helical pattern around the inner shell. The helical guide
vanes increases residence time of the product gas inside the
annular space and causes heat transfer from the product gas to the
surroundings inner shell.
[0032] According to one embodiment herein, the system provides a
gap of predetermined size between the inner surface of the outer
shell and the helical guide vanes. The gap is configured to freely
drop down ash and other solid condensable contaminants to bottom of
the reactor.
[0033] According to one embodiment herein, the automatic start
system comprises a Liquefied Petroleum Gas (LPG) fuel line
connected to a burner assembly. The LPG is ignited by a built-in
spark plug.
[0034] According to one embodiment herein, the system comprises a
digital control system such as a Programmable Logic Circuits (PLC)
for controlling the inlet of LPG and ignition of the spark plug. A
control valve is provided to operate a start and stop of combustion
process. The control valve is commanded by the digital control
system.
[0035] According to one embodiment herein, the system comprises a
suction blower configured to apply suction at the outer pipe. The
suction draws the air from the burner and preheats the air to a
predetermined temperature.
[0036] According to one embodiment herein, the system further
comprises a lifting bracket configured to lift and place the
gasifier from one location to another location. The lifting bracket
is welded to the outer surface of the outer shell.
[0037] According to one embodiment herein, the system further
comprises a hearth provided to support the fuel under combustion
and permits a pile of glowing charcoal underneath. The charcoal
filters the product gas by breaking down the tar into combustible
compounds.
[0038] According to one embodiment herein, the system further
comprises a plurality of radial gas separation holes provided in
the wall of the inner shell of the reactor. The holes are
configured to separate the product gas from the charcoal. The holes
block the charcoal and permit only the product gas to exit from the
inner shell to the annular space.
[0039] According to one embodiment herein, the stirrer assembly
comprises a stirrer configured to stir the glowing charcoal bed so
as to prevent blockages leading obstruction of gas flow. The
stirrer is driven by a gear box connected to a motor, wherein the
stirrer is rotated by the motor. The stirrer shaft passes through a
plurality of glands and enters the bottom of the reactor.
[0040] According to one embodiment herein, the system further
comprises an ash removal funnel placed in the annular space between
the inner shell and the outer shell. The ash removal funnel is
mounted on an ash removal flange. The ash removal funnel collects
the ash dropped to the bottom of the reactor and the collected ash
is taken out by the ash removal flange.
[0041] According to one embodiment herein, the support system
comprises a plurality of support brackets which are sustained by a
plurality of stands configured to support the reactor system.
[0042] According to one embodiment herein, the system further
comprises a gas blower attached to the reactor which enhances start
performance and transient response to the load changes. A cyclonic
separator is configured to enhance the purity of gas by reducing
contamination load on water scrubber and preventing the clogging of
water scrubber.
[0043] According to one embodiment herein, the system further
comprises an infrared laser beam configured to detect and indicate
level of fuel consumption inside the reactor.
[0044] According to one embodiment herein, the system comprises a
safety unit configured to automatically shutting down the reactor
for a variety of out-of-limit operating parameters. The parameters
include a high reactor pressure, a high reactor temperature, a high
water temperature, a low water level, a water pump failure, a low
frequency, a high frequency, a gas leakage and the like.
[0045] The embodiments herein provide an improved biomass based
down draft gasifier for producing electrical energy. The improved
down draft gasifier provides a simple construction with easily
removable and adjustable components and a method for using the
same. The down draft gasifier comprises a reactor with a double
walled construction. The inner surface of the wall is referred to
as an inner shell and the outer surface is referred to as an outer
shell. The annular space between the outer shell and the inner
shell houses a helical guide vanes welded to the inner shell. The
top of the reactor is covered with a spring loaded top cover
assembly. The down draft gasifier further comprises an air inlet
manifold around the outer shell for directing a controlled air into
a combustion zone of the reactor through a set of three or more air
inlet nozzles. An automatic start system is also provided to
control the combustion of inlet fuel and ignition of the fuel from
a spark plug. The gasifier further comprises a throat which permits
the ashes and charcoal of burnt fuel to drop to the bottom of the
reactor. Plurality of Radial gas separation holes are provided on
the wall of the inner shell which assists in separating a product
gas from the charcoal. The product gas flows in the annular space
between the inner and outer shells. The product gas is guided by
the helical guide vanes to flow in a helical pattern around the
inner shell.
[0046] According to one embodiment herein, a method for operating
the improved down draft gasifier is provided. The method is
categorized corresponding to four zones of operations comprising a
drying zone, a distillation zone, a combustion zone and a char
zone. In the drying zone, the solid fuels such as wood, rice husks,
etc are used. The solid fuels of preferred sizes are selected based
on the type of reactor and the corresponding configuration. The
reactor of the gasifier is loaded with a solid fuel such as woody
biomass, rise husks, etc and the top cover assembly is closed. The
solid fuel undergoes heating to remove any moisture content by the
product gas in the annular region.
[0047] According to one embodiment herein, the content of the fuel
is extracted by the application of heat in the distillation zone.
In the distillation zone, the solid fuel undergoes distillation by
causing the volatile contents to become vaporized leaving behind
the charcoal and ash. The heating is performed by a product gas in
the annular space of the double layered wall. Also, the heat
generated in the combustion zone also causes the above placed fuel
to undergo a distillation process.
[0048] According to one embodiment herein, the combustion zone
comprises smoldering of the fuel. In the combustion zone, the
combustion of solid fuel is initiated by igniting a combustion gas
from a spark plug. The combustion causes the smoldering of the
fuel. When the top cover assembly is closed, the LPG is taken as
input and is ignited by the spark plug. A suction is applied at the
output pipe either by using a venturi scrubber or by a suction
blower. The suction draws the air from the burner and preheats the
air to a predetermined temperature such as around 5000-7000. The
heated air enters into the air nozzle and is supplied to the fuel.
The fuel undergoes combustion and with a controlled flow of air
inside the reactor, smoldering of fuel is achieved. The fuel
undergoes smoldering leaving behind the charcoal and ash. The
charcoal and ash drops down from the hearth to the bottom of the
reactor.
[0049] According to one embodiment herein, the gases produced in
the combustion zone due to the smoldering enter into the char zone.
In the char zone, the product gas is separated from the ashes and
charcoal with the help of plurality of radial gas separation
holes.
[0050] According to one embodiment herein, the product gases
produced from the char zone flows into the annular region between
the inner shell and outer shell. The product gas is guided by the
helical guide vanes to flow in a helical pattern around the outer
periphery of the inner shell towards the output pipe. The helical
guide vanes also increase the residence time of the product gas
within the annular region and enables the product gas to undergo a
secondary reaction while moving upward through the annular region.
In the secondary reaction, carbon dioxide reacts with oxygen to
form carbon monoxide and water. The increased residence time of the
product gas in the annular region transfers the heat to the fuel
inside the inner shell for preheating and drying of the fuel and to
the surrounding. This increases and enhances the efficiency of the
gasifier. Once the fuel is consumed, the top cover assembly is
opened and fuel is added.
[0051] According to one embodiment herein, regenerative heating is
achieved by the double walled cylinders and the helical guide
vanes. The product gas is cooled down significantly inside the
annular region which also decreases the tar content. As the product
gas moves upward in the annular space, the tar condenses on the
inner surface of the outer shell and flows down to the bottom. The
tar also experiences heat from the inner shell. The heat breaks
down the long chain compounds of the tar into smaller compounds.
The smaller compounds are also a form of a fuel. The temperature of
the product gas is lowered significantly thereby leading to a
minimal usage of water for cooling.
[0052] According to one embodiment herein, a set of helical guide
vanes are provided within the annular space of the double layered
wall. The helical guide vanes guide the product gas from the bottom
of the reactor to the output pipe. The helical guide vanes
increases the residence time of the product gas inside the annular
space and thus causes the product gas to transfer the heat to the
inner shell and to the surroundings. The increased residence time
of the product gas also reduces its temperature thereby minimizing
the usage of water to cool down the gas to a required temperature.
The extended residence time at lower flow velocities encourages a
drop-out of the particulates into an ash removal funnel. The heat
transferred from the product gas to the fuel in the reactor helps
to reduce a moisture content of the fuel. The heating of reactor
inner shell prevents a condensation of tar and an adhesion of wood
chunks to the inner shell. The double layered wall also minimizes
water consumption and provides a higher efficiency due to a capture
of the heat in product gas back into the input fuel.
[0053] According to one embodiment herein, the improved down draft
gasifier comprises a safety feature for protection against an
overpressure or explosion. The top cover assembly of the reactor
comprises a spring loaded structure which automatically opens
during an overpressure or an explosion inside the reactor.
[0054] According to one embodiment herein, a system and method for
remotely controlling an input air into the reactor is provided. The
system comprises an air inlet manifold fixed around the outer
shell. The inlet manifold supplies the air to three or more inlet
nozzles for the smoldering of the fuel inside the reactor. The
usage of only one inlet manifold for supplying a required air
inside the reactor provides a better control to an operator from a
remote place. A digital control system is used for controlling the
air inlet, spark plug and the control valve inside the reactor.
Further, the air inlet nozzle is adjustable to a required
penetration inside the reactor before the reactor is initiated.
[0055] According to one embodiment herein, the system and method
facilitates turn-key operational ease, with plain language
annunciation. The operation of the gasifier requires a minimum
manpower and minimum training, ensures correct and safe procedures
for start and stop, continuous automated safety and health
monitoring, safety trips implemented and eliminates tar formation
after shut-down. The gasifier adopts and implements safety trips
for shutting down the reactor safely and automatically for a
variety of out-of-limit operating parameters. The parameters
include a high reactor pressure, a high reactor temperature, a high
water temperature, a low water level, a water pump failure, a low
frequency, a high frequency, a gas leakage, etc. An enhanced remote
monitoring minimizes the manpower, allows health parameter trending
and failure prevention, enhances uptime and permits system-wide
management.
[0056] According to one embodiment herein, a polished stainless
steel construction is provided to the down draft gasifier. The
stainless steel provides superior aesthetics, corrosion resistant,
negligible maintenance, extended life and smoother fuel feeding.
The reactor is provided with a straight cylindrical design which
improves fuel feeding and prevents clogging. Further, the straight
design eliminates the need for a vibrator.
[0057] According to one embodiment herein, the product gas is
cooled by scrubber water through radiator which eliminates
spray-cooling and attendant water losses and minimizes a large
requirement of water quantity.
[0058] According to one embodiment herein, a gas blower is added to
the reactor which enhances a start performance, permits use of
cyclonic separator, and enhances transient response to the load
changes. The cyclonic separator enhances purity of gas, reduces
contamination load on water scrubber, and prevents clogging of
venturi scrubber. The welded stainless steel pipelines for product
gases are compliant with international safety requirements.
[0059] According to one embodiment herein, an infrared laser beam
is provided to detect and indicate a level of fuel consumption
inside the reactor. The infra red lasers are used instead of
visible-light laser and normal light because of their ability to
penetrate through the smoke inside the reactor.
[0060] These and other aspects of the embodiments herein will be
better appreciated and understood when considered in conjunction
with the following description and the accompanying drawings. It
should be understood, however, that the following descriptions,
while indicating the preferred embodiments and numerous specific
details thereof, are given by way of an illustration and not of a
limitation. Many changes and modifications may be made within the
scope of the embodiments herein without departing from the spirit
thereof, and the embodiments herein include all such
modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0061] The other objects, features and advantages will occur to
those skilled in the art from the following description of the
preferred embodiment and the accompanying drawings in which:
[0062] FIG. 1 illustrates a cross sectional view of an improved
down draft gasifier, according to one embodiment herein.
[0063] FIG. 2 illustrates a front view of a down draft gasifier
with a system for filtering a product gas, according to one
embodiment herein.
[0064] FIG. 3 illustrates a schematic view of an electrical power
generation system with the down draft gasifier, according to one
embodiment herein.
[0065] Although the specific features of the embodiments herein are
shown in some drawings and not in others. This is done for
convenience only as each feature may be combined with any or all of
the other features in accordance with the embodiments herein.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0066] In the following detailed description, a reference is made
to the accompanying drawings that form a part hereof, and in which
the specific embodiments that may be practiced is shown by way of
illustration. These embodiments are described in sufficient detail
to enable those skilled in the art to practice the embodiments and
it is to be understood that the logical, mechanical and other
changes may be made without departing from the scope of the
embodiments. The following detailed description is therefore not to
be taken in a limiting sense.
[0067] The various embodiments herein provide a down draft gasifier
for generating energy. The gasifier comprises a reactor, a top
cover assembly, an air inlet assembly, an automatic start unit, a
stirrer assembly and a support system. The reactor is configured to
smolder a solid fuel to produce product gas. The product gas is
used to generate required energy. The top cover assembly arranged
on top of the reactor is configured to provide protection to a
surrounding environment from any hazardous situations created in
the reactor. The air inlet assembly is configured for directing
controlled air into a combustion zone of the reactor through a set
of air inlet nozzles. The air is used for combustion of the solid
fuel to produce the product gas. The automatic start unit is
configured to control the combustion of the inlet solid fuel. The
stirrer assembly configured to break the solid fuel into lumps for
enabling the stable gas flow. The support system configured to
sustain weight of the reactor assembly. The reactor is loaded with
a solid fuel. The reactor is a double walled construction
comprising an inner shell and an outer shell. The reactor further
comprises a helical guide vane configured to assist a uniform flow
of the product gas around the outer peripheral surface of the inner
shell. The system comprises an output pipe mounted at extreme top
end of the outer shell is configured to eject the product gas
yielded from the reactor.
[0068] According to one embodiment herein, the top cover assembly
is a spring loaded top cover which automatically opens during an
overpressure or an explosion inside the reactor. The top cover
assembly is fastened to a top flange of the reactor using a
plurality of bolts. The top cover assembly is fastened in a
circular manner so as to seal the top of reactor.
[0069] According to one embodiment herein, the air inlet assembly
comprises an air inlet manifold provided at the outer surface of
the outer shell. The air inlet manifold is configured to supply the
air required for combustion of the fuel inside the reactor through
a plurality of air inlet nozzles. The plurality of air inlet
nozzles is configured to control the quantum of air into the
reactor chamber and facilitate a quick replacement in case of
corrosion.
[0070] According to one embodiment herein, the air inlet nozzle is
adjustable to a required penetration inside the reactor before an
initiation of the reactor. The air inlet nozzle is inserted into an
outer pipe. The outer pipe is welded with the inner shell and
housed inside a gland.
[0071] According to one embodiment herein, the gland allows a free
thermal expansion of the air inlet nozzle and avoids a formation of
crack on the output pipe due to stress, heat and a differential
growth between the inner shell and the outer shell of the
reactor.
[0072] According to one embodiment herein, the system further
comprises an angular space between the outer shell and the inner
shell of the reactor. The angular space houses the helical guide
vanes which are welded to the inner shell of the reactor.
[0073] According to one embodiment herein, the helical guide vane
is in the form of a multi strand thread to guide the product gas to
flow in a helical pattern around the inner shell. The helical guide
vanes increases a residence time of the product gas inside the
annular space and causes a heat transfer from the product gas to
the surroundings inner shell.
[0074] According to one embodiment herein, the system provides a
gap of predetermined size between the inner surface of the outer
shell and the helical guide vanes. The gap is configured to freely
drop down ash and other solid condensable contaminants to bottom of
the reactor.
[0075] According to one embodiment herein, the automatic start
system comprises a Liquefied Petroleum Gas (LPG) fuel line
connected to a burner assembly. The LPG is ignited by a built-in
spark plug.
[0076] According to one embodiment herein, the system comprises a
digital control system such as a Programmable Logic Circuits (PLC)
for controlling the inlet of LPG and ignition of the spark plug. A
control valve is provided to operate a start and stop of a
combustion process. The control valve is commanded by the digital
control system.
[0077] According to one embodiment herein, the system comprises a
suction blower configured to apply suction at the outer pipe. The
suction draws the air from the burner and preheats the air to a
predetermined temperature.
[0078] According to one embodiment herein, the system further
comprises a lifting bracket configured to lift and place the
gasifier from one location to another location. The lifting bracket
is welded to the outer surface of the outer shell.
[0079] According to one embodiment herein, the system further
comprises a hearth provided to support the fuel under combustion
and permits a pile of glowing charcoal underneath. The charcoal
filters the product gas by breaking down the tar into combustible
compounds.
[0080] According to one embodiment herein, the system further
comprises a plurality of radial gas separation holes provided in
the wall of the inner shell of the reactor. The holes are
configured to separate the product gas from the charcoal. The holes
block the charcoal and permit only the product gas to exit from the
inner shell to the annular space.
[0081] According to one embodiment herein, the stirrer assembly
comprises a stirrer configured to stir the glowing charcoal bed so
as to prevent blockages leading obstruction of gas flow. The
stirrer is driven by a gear box connected to a motor, wherein the
stirrer is rotated by the motor. The stirrer shaft passes through a
plurality of glands and enters the bottom of the reactor.
[0082] According to one embodiment herein, the system further
comprises an ash removal funnel placed in the annular space between
the inner shell and the outer shell. The ash removal funnel is
mounted on an ash removal flange. The ash removal funnel collects
the ash dropped to the bottom of the reactor and the collected ash
is taken out by the ash removal flange.
[0083] According to one embodiment herein, the support system
comprises a plurality of support brackets which are sustained by a
plurality of stands configured to support the reactor system.
[0084] According to one embodiment herein, the system further
comprises a gas blower attached to the reactor which enhances start
performance and transient response to the load changes. A cyclonic
separator is configured to enhance the purity of gas by reducing
contamination load on water scrubber and preventing the clogging of
water scrubber.
[0085] According to one embodiment herein, the system further
comprises an infrared laser beam configured to detect and indicate
level of fuel consumption inside the reactor.
[0086] According to one embodiment herein, the system comprises a
safety unit configured to automatically shutting down the reactor
for a variety of out-of-limit operating parameters. The parameters
include a high reactor pressure, a high reactor temperature, a high
water temperature, a low water level, a water pump failure, a low
frequency, a high frequency, a gas leakage and the like.
[0087] The embodiments herein provide an improved biomass based
down draft gasifier for producing electrical energy. The improved
down draft gasifier provides a simple construction with easily
removable and adjustable components and a method for using the
same. The down draft gasifier comprises a reactor with a double
walled construction. The inner surface of the wall is referred to
as an inner shell and the outer surface is referred to as an outer
shell. The annular space between the outer shell and the inner
shell houses a helical guide vanes welded to the inner shell. The
top of the reactor is covered with a spring loaded top cover
assembly. The down draft gasifier further comprises an air inlet
manifold around the outer shell for directing a controlled air into
a combustion zone of the reactor through a set of three or more air
inlet nozzles. An automatic start system is also provided to
control the combustion of inlet fuel and ignition of the fuel from
a spark plug. The gasifier further comprises a throat which permits
the ashes and charcoal of burnt fuel onto the bottom of the
reactor. Plurality of Radial gas separation holes are provided on
the wall of the inner shell underneath the throat which assists in
separating a product gas from the charcoal. The product gas is
taken out from the double layered wall through a set of helical
guide vanes to an output pipe.
[0088] According to one embodiment herein, a method for operating
the improved down draft gasifier is provided. The method is
categorized corresponding to four zones of operations comprising a
drying zone, a distillation zone, a combustion zone and a char
zone. In the drying zone, the solid fuels such as wood, rice husks,
etc are used. The solid fuels of preferred sizes are selected based
on the type of reactor and the corresponding configuration. The
reactor of the gasifier is loaded with a solid fuel such as woody
biomass, rise husks, etc and the top cover assembly is closed. The
solid fuel undergoes heating to remove any moisture content by the
product gas in the annular region.
[0089] According to one embodiment herein, the content of the fuel
is extracted by the application of heat in the distillation zone.
In the distillation zone, the solid fuel undergoes distillation by
causing the volatile contents to become vaporized leaving behind
the charcoal and ash. The heating is performed by product gas in
the annular space of the double layered wall. Also, the heat
generated in the combustion zone also causes the above placed fuel
to undergo a distillation process.
[0090] According to one embodiment herein, the combustion zone
comprises smoldering of the fuel. In the combustion zone, the
combustion of solid fuel is initiated by igniting the combustion
gas with the help of a spark plug. The combustion causes the
smoldering of the fuel. When the top cover assembly is closed, the
LPG is taken as input and is ignited by the spark plug. A suction
is applied at the output pipe either by using a venturi scrubber or
by a suction blower. The suction draws the air from the burner and
preheats the air to a predetermined temperature such as around
5000-7000. The heated air enters into the air nozzle and is
supplied to the fuel. The fuel undergoes combustion and with a
controlled flow of air inside the reactor and a smoldering of fuel
is achieved. The fuel undergoes smoldering leaving behind the
charcoal and ash. The charcoal and ash drops down from the hearth
to the bottom of the reactor inner shell.
[0091] According to one embodiment herein, the gases produced in
the combustion zone due to the smoldering enter into the char zone.
In the char zone, the product gas is separated from the ashes and
charcoal with the help of radial gas separation holes provided in
the wall of the inner shell.
[0092] According to one embodiment herein, the product gases
produced from the char zone flows into the annular region between
the inner shell and outer shell. The product gas is guided by the
helical guide vanes to flow in a helical pattern around an outer
periphery of the inner shell to the output pipe. The helical guide
vanes also increase the residence time of the product gas within
the annular region and enables the product gas to undergo a
secondary reaction while moving upward through the annular region.
In the secondary reaction, carbon dioxide reacts with oxygen to
form carbon monoxide and water. The increased residence time of the
product gas in the annular region transfers the heat to the fuel
inside the inner shell for preheating and drying of the fuel and to
the surrounding. This increases and enhances the efficiency of the
gasifier. Once the fuel is consumed, the top cover assembly is
opened and a new fuel is added.
[0093] According to one embodiment herein, a regenerative heating
is achieved by the double walled cylinders and the helical guide
vanes. The product gas is cooled down drastically inside the
annular region which also decreases the tar content. As the product
gas moves upward in the annular space, the tar condenses on the
inner surface of the outer shell and flows down to the bottom. The
tar also experiences heat from the inner shell. The heat breaks
down the long chain compounds of the tar into smaller compounds.
The smaller compounds are also a form of a fuel. The temperature of
the product gas is lowered significantly thereby leading to a
minimal usage of water for cooling.
[0094] According to one embodiment herein, a set of helical guide
vanes are provided within the annular space of the double layered
wall. The helical guide vanes guide the product gas from the bottom
of the reactor to the output pipe. The helical guide vanes
increases the residence time of the product gas inside the annular
space and thus causes the product gas to transfer the heat to the
inner shell and to the surroundings. The increased residence time
of the product gas also reduces its temperature thereby minimizing
the usage of water to cool down the gas to a required temperature.
The extended residence time at lower flow velocities encourages a
drop-out of the particulates into an ash removal funnel. The heat
transferred from the product gas to the fuel in the reactor helps
to reduce a moisture content of the fuel. The heating of reactor
inner shell prevents a condensation of tar and an adhesion of wood
chunks to the inner shell. The double layered wall also minimizes
water consumption and provides a higher efficiency due to heat
capture from product gas back into the input fuel.
[0095] According to one embodiment herein, the improved down draft
gasifier comprises a safety feature for protection against an
overpressure or explosion. The top cover assembly of the reactor
comprises a spring loaded structure which automatically opens
during an overpressure or an explosion inside the reactor.
[0096] According to one embodiment herein, a system and method for
remotely controlling an input air into the reactor is provided. The
system comprises an air inlet manifold fixed around the outer
shell. The inlet manifold supplies the air to three or more inlet
nozzles for the smoldering of the fuel inside the reactor. The
usage of only one inlet manifold for supplying required air inside
the reactor provides a better control to an operator from a remote
place. A digital control system is used for controlling the air
inlet, spark plug and the control valve inside the reactor.
Further, the air inlet nozzle is adjustable to a required
penetration inside the reactor before the reactor is initiated.
[0097] According to one embodiment herein, the system and method
facilitates turnkey operational ease, with plain language
annunciations. The operation of the gasifier requires a minimum
manpower and minimum training, ensures correct and safe procedures
for start and stop, continuous automated safety and health
monitoring, safety trips implemented and eliminates tar formation
after shut-down. The gasifier adopts and implements safety trips
for shutting down the reactor safely and automatically for a
variety of out-of-limit operating parameters. The parameters
include a high reactor pressure, a high reactor temperature, a high
water temperature, a low water level, a water pump failure, a low
frequency, a high frequency, a gas leakage, etc. An enhanced remote
monitoring minimizes the manpower, allows health parameter trending
and failure prevention, enhances uptime and permits system-wide
management.
[0098] According to one embodiment herein, a polished stainless
steel construction is provided to the down draft gasifier. The
stainless steel provides superior aesthetics, corrosion resistant,
negligible maintenance, extended life and smoother fuel feeding.
The reactor is provided with a straight cylindrical design which
improves fuel feeding and prevents clogging. Further, the straight
design eliminates the need for a vibrator.
[0099] According to one embodiment herein, the product gas is
cooled by scrubber water through radiator which eliminates
spray-cooling and attendant water losses and minimizes a large
requirement of water quantity.
[0100] According to one embodiment herein, a gas blower is added to
the reactor which enhances a start performance, permits use of
cyclonic separator, and enhances transient response to the load
changes. The cyclonic separator enhances purity of gas, reduces
contamination load on water scrubber, and prevents clogging of
venturi scrubber. The welded stainless steel pipelines for product
gases are compliant with international safety requirements.
[0101] According to one embodiment herein, an infrared laser beam
is provided to detect and indicate a level of fuel consumption
inside the reactor. The infrared lasers are used instead of
visible-light laser and normal light because of their ability to
penetrate through the smoke inside the reactor.
[0102] FIG. 1 illustrates a cross sectional view of an improved
down draft gasifier, according to one embodiment herein. The down
draft gasifier 100 comprises a reactor chamber formed by an outer
shell 103 and an inner shell 104. The outer shell 103 and the inner
shell 104 create an annular space 121 in between thereby providing
a double walled construction to the reactor. The outer shell 103
and the inner shell 104 are manufactured from Austentic stainless
steel for providing a protection against corrosion and erosion. The
outer shell 103 also assists in radiating an excessive heat from a
product gas to the surroundings. The thickness of the inner shell
104 is greater than that of the outer shell 103 for providing a
longer life to the reactor. The inner shell 104 is subjected to
very high reactor temperatures of around 10000 Celsius. The inner
shell 104 is able to withstand the inner reducing atmosphere of
hydrogen and carbon monoxide without requiring any refractory
lining.
[0103] A lifting bracket 102 is welded to the outer surface of the
outer shell 103. The lifting bracket 102 allows the gasifier 100 to
be lifted and placed from one location to another location. The
product gas yielded from the down draft reactor is taken out
through an output pipe 123. The output pipe 123 is mounted at
extreme top end of the outer shell 103. The position of the output
pipe 123 provides a high residence time to the product gas inside
the annular space 121 between the outer shell 103 and the inner
shell 104. The high residence time also enables the product gas to
complete all water gas reactions and transfer maximum heat to the
inner shell 104. The temperature of the product gas taken out from
the output pipe 123 is reduced significantly to lower than hundred
degrees Celsius. The top of the reactor is covered with a top cover
assembly 101. The top cover assembly 101 is fastened to the top
flange by means of bolts 124 in a circular manner and thereby seals
the top of the reactor. The top cover assembly 101 is a spring
loaded top cover providing a protection against over pressure due
to any explosion or configuration of the reactor.
[0104] The outer surface of the inner shell 104 is welded with
plurality of helical guide vanes 122. The helical guide vanes 122
are in the form of multi strand thread which assists a uniform flow
of product gas around the outer peripheral surface of the inner
shell 104. The helical guide vanes 122 enhance the heat dissipation
of the product gas by transferring heat to the fuel inside the
inner shell 104 and to the surroundings. The helical guide vanes
122 increases the residence time of the product gas for completing
all the water gas reactions and further lowers the output
temperature of the product gas before exiting the reactor. The
helical guide vanes 122 are arranged in a manner that no contact is
made with the inner surface of the outer shell 103. A gap of
predetermined size is provided between the inner surface of the
outer shell 103 and the helical guide vanes 122 to permit the ash
and other solid contaminants to drop down to the bottom of the
reactor. The gap also permits any condensed or condensable material
such as tar to freely flow down from the inner surface of the outer
shell 103 to the bottom of the reactor.
[0105] The down draft gasifier 100 further comprises an air inlet
manifold 120 provided at the outer surface of the outer shell 103.
The air inlet manifold 120 provides the required air for the
combustion of the fuel inside the reactor through a set of three or
more air inlet nozzle 108. The common air inlet manifold 120
provides an ease of starting and shutdown of the reactor by
controlling a single control valve 105. The design of air inlet
nozzle 108 facilitates a quick replacement in case of corrosion and
also provides a control to adjust the quantum of air into the
reactor chamber. The air inlet nozzle 108 is inserted into an outer
pipe 106. The outer pipe 106 is welded with the inner shell 104 and
housed inside a gland 107. The gland 107 is fixed to the outer
shell 103. The gland 107 allows a free thermal expansion and avoids
a formation of crack of the output pipe due to stresses, heat and a
differential growth between the inner shell 104 and the outer shell
103 of the reactor. The gland 107 allows a free expansion of the
air inlet nozzle 108. The air inlet nozzle 108 fits inside the air
inlet pipe and penetrates inside the fuel. The air inlet nozzle 108
penetrates to a predetermined extent inside the reactor based on
the type of fuel. The air inlet nozzle 108 allows for adjusting the
temperature of the fuel, adjusting the size of the air nozzle tip
for controlling the power output from the reactor with a quick
replacement feature.
[0106] The down draft gasifier 100 further comprises an automatic
start system 119. The automatic start system 119 comprises a
Liquefied Petroleum Gas (LPG) fuel line connected to a burner
assembly. The LPG is ignited by a built-in spark plug. The inlet of
LPG and the ignition of the spark plug are commanded from a digital
control system such as a Programmable Logic Circuits (PLC). A
control valve 105 is opened during start of the combustion process
and closed for stopping the same process. The control valve 105 is
also commanded by the digital control system. A hearth or throat
118 is provided to support the fuel under combustion and permits
the pile of glowing charcoal underneath. The charcoal filters the
gases and breaks down tar into combustible compounds. The hearth
118 is not welded to the reactor and is easily removable. The
hearth 118 is removable for treating the corrosion at high
temperatures and for periodic cleaning of the reactor. The reactor
system is supported on two or more support brackets 117. The
support brackets 117 are sustained on same number of stands 113. A
plurality of Radial gas separation holes 116 are provided in the
wall of the inner shell of the reactor. The holes 116 separate the
product gas from the charcoal by blocking the charcoal and
permitting only the product gas to exit from the inner shell 104 to
the annular space 121. Further, at the bottom of the reactor,
glands for a stirrer 115 are provided. The stirrer 115 is driven by
a gear box 112 connected to a motor 114. The stirrer 115 shaft
passes through the glands and enters the bottom of the reactor. The
stirrer shaft is rotated by means of motor 114 coupled to the gear
box 112. The bottom of the doubled layered wall functions an ash
removal funnel 110. The ash removal funnel 110 is formed in the
annular space 121 between the inner shell 104 and the outer shell
103. The constructional design of the ash removal funnel 110 allows
easy mounting of bottom flange and also easy and free removal of
the bottom flange. The ash removal funnel 110 assembly also allows
easy mounting and dismounting of stirrer 115 assembly along with
the bottom flanges. The removable stirrer 115 assembly and the
bottom flanges also allow an easy cleaning of the reactor. The
bottom of the ash removal funnel 110 is mounted with an ash removal
flange 111. The ash dropped in the ash removal funnel 110 is
collected at the removal flange 111 and then is taken out by an ash
removal system. A set of bolts closes/seals the inner shell 104
with the bottom flange.
[0107] FIG. 2 illustrates a system for filtering a product gas
obtained from the down draft gasifier, according to one embodiment
herein. The output pipe of the gasifier 100 is connected with a
venturi scrubber 201. The venturi scrubber 201 removes any fine
particle of ashes or other solid particles carried forward by the
product gas. The producer gas is then passed through a sawdust
filter 202 for further removing any remaining insoluble part of the
tar or any carry-over sediments. The soluble tar or particles are
captured in the water storage tank 205. The water is recycled and
is again used in the same water tank. The insoluble tar is removed
from by using a filter bed. The product gas is then finally passed
through a fabric filter 203. The fabric filter 203 removes any left
out particles from the product gas. The product gas from the fabric
filter 203 is directed to an IC engine for generating electric
power.
[0108] FIG. 3 illustrates a system for generating electric power
from the producer gas obtained from the down draft gasifier,
according to one embodiment herein. The down draft gasifier 100 is
operated and product gas is obtained from the output pipe. The
producer gas goes through plurality of filtration process and is
passed into an internal combustion (IC) engine 302. The product gas
undergoes combustion in the IC engine 302 which drives a generator
for generating electric power. A control panel 301 is used which
controls the output of the generator.
[0109] The embodiments herein provide an improved and efficient
gasifier system for generating electric power. The system provides
a system for remotely monitoring an operation of the down draft
gasifiers and accordingly decrease a temperature of an output gas
to an optimum level. The system provides the gasifier with a
helical guide for output gas flow to preheat the fuel thereby
utilizing the heat of the output gas. The remote monitoring
facility of the gasifier minimizes the requirement of manpower and
automates the failure prevention, to enhance uptime and to permit a
system-wide management. The gasifier is provided with a Polished
Stainless Steel construction to provide a superior aesthetics
design, corrosion and erosion resistant properties, negligible
maintenance, extended life and smoother fuel feeding operation. The
gasifier facilities a drop-out of the particulates into an ash
removal chute and to transfer the heat from the output gas to the
fuel in the feed hopper to reduce moisture content. The system
transfers the heat to a hopper inner wall to prevent condensation
of tar and adhesion of wood chunks to the wall. The system reduces
the temperature of output gas and minimizes water consumption used
for cooling down the output gas. The system provides a higher
efficiency due to the capture of heat in product gas back into the
input fuel.
[0110] The foregoing description of the specific embodiments will
so fully reveal the general nature of the embodiments herein that
others can, by applying current knowledge, readily modify and/or
adapt for various applications such specific embodiments without
departing from the generic concept, and, therefore, such
adaptations and modifications should and are intended to be
comprehended within the meaning and range of equivalents of the
disclosed embodiments.
[0111] It is to be understood that the phraseology or terminology
employed herein is for the purpose of description and not of
limitation. Therefore, while the embodiments herein have been
described in terms of preferred embodiments, those skilled in the
art will recognize that the embodiments herein can be practiced
with modifications.
[0112] Although the embodiments herein are described with various
specific embodiments, it will be obvious for a person skilled in
the art to practice the embodiments herein with modifications.
[0113] It is also to be understood that the following claims are
intended to cover all of the generic and specific features of the
embodiments described herein and all the statements of the scope of
the embodiments which as a matter of language might be said to fall
there between.
* * * * *