Title of Invention	A BLAST FURNACE GAS FIRED STEAM BOILER
Abstract	High efficiency fully automatic safe and reliable compact blast furnace gas fired steam boiler comprising of refractory lined combustion chamber for combustion of BFG with air staged axial swirl type BFG burners provided for burning of BFG at front end;smoke tube type evaporator provided for steam generation installed at the exit of combustion chamber;pilot fuel burner provided at front end of combustion chamber for cold start of BFG combustion chamber which can be act as stand by burner as well;the balanced draft system comprising of forced draft fan; dilution air fan,induced draft fan,gas ducting and draft control system;gas train provided for regulation and modulationof of blast furnace gas flow and pressure into the combustion chamber;instruments,control and safeties for automatic and reliable operation of the boiler .

Title of Invention

A BLAST FURNACE GAS FIRED STEAM BOILER

Abstract

High efficiency fully automatic safe and reliable compact blast furnace gas fired steam boiler comprising of refractory lined combustion chamber for combustion of BFG with air staged axial swirl type BFG burners provided for burning of BFG at front end;smoke tube type evaporator provided for steam generation installed at the exit of combustion chamber;pilot fuel burner provided at front end of combustion chamber for cold start of BFG combustion chamber which can be act as stand by burner as well;the balanced draft system comprising of forced draft fan; dilution air fan,induced draft fan,gas ducting and draft control system;gas train provided for regulation and modulationof of blast furnace gas flow and pressure into the combustion chamber;instruments,control and safeties for automatic and reliable operation of the boiler .

Full Text	FORM-2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 PROVISIONAL SPECIFICATION (See section 10 rule 13) "HIGH EFFICIENCY BLAST FURNACE GAS FIRED STEAM BOILER" ASHOK DATTATRAYA ATRE 'Pushpa heights', 1st floor, Bibwevadi Corner, PUINE- 411 037, MAHARASHTRASTATE, INDIA Indian National The following specification describes the nature of the invention FIELD OF THE INVENTION Present invention relates to high efficiency Blast Furnace Gas (BFG) Fired Steam Boiler. PRIOR ART In prior art the BFG Fired Boilers are either water tube type boilers or fire tube type boilers. The said BFG Fired Boilers are having forced draught arrangement. These BFG fired boilers need the support fuel in the form of either gas or oil to sustain the BFG flame. The requirement of support fuel is generally upto 30% of the total heat input required for the boiler. In these BFG fired boilers there is water walled furnace where radiant heat transfer takes place. Taking into consideration the known BFG fired boilers following have dis-advantages- 1) BFG being a lean burning gas and furnace being water cooled in construction, the support fuel in the form of oil or gas is always required to be burnt to sustain the flame of BFG. 2) Due tQ absence of thermal inertia and BFG being a lean burning gas, during every restart, the boiler needs to be started with only supposing fuel till the boiler is stabilized and the furnace achieves the temperature of typically 700 Deg. C. 3) The requirement of support fuel increases the running cost of the boiler, as the cost of oil / gas is substantially higher compared to BFG. Even if BFG is available with the user in sufficient quantity • and at low cost, the same can not be fully utilized due to the continuous requirement of support fuel. 4) Since the BFG can not be stored in large quantities, the excess BFG has to be flared and burnt in the atmosphere thereby resulting in substantial loss of heat. This also causes release of excessive Carbon dioxide (C02) gas into the atmosphere, which is considered as a green house gas responsible for global warming. 5) Additional investment in the form of support fuel burner, the fuel handling, storage and preparation is required. 6) The BFG contains approximately 20 to 25% by weight of Carbon monoxide (CO), which is a hazardous gas for human being who are exposed to the same and is also considered as the pollutant. 7) In case of even minor leakage from the furnace of the BFG fired boiler, there exists Tire, explosion and health hazard due to leakage of unburnt BFG in the atmosphere. 8) The conventional BFG fired boilers do not have heat recovery units and are hence less efficient. SUMMARY OF THE INVENTION The present invention aims to provide a high efficiency BFG fired steam boiler. It is also the object of the present invention to provide the BFG fired boiler, which does not, require any support fuel except during cold start. It is also the object of the present invention to overcome and eliminate the drawbacks and short falls of the prior art. In the boiler of the present invention BFG is burnt in a hot refractory lined furnace. The air required for combustion of BFG is supplied by a forced draft fan. A dilution air fan is also provided to maintain the flue gas temperature in the range of 1000 to 1200 Deg. C. The flue gases are passed through a fire tube boiler and steam is generated. The flue gases leaving the boiler at a temperature of 30Q to 400 degrees are passed through an economiser where feed water is preheated from 90 degrees to nearly saturation temperature. A superheater can also be provided as an optional device between boiler and economiser to suit the specific requirement. The furnace is maintained under slightly negative pressure by an induced draft fan. The steam generation and steam pressure is controlled through a stepless modulating control system. The flow of BFG into the boiler furnace is controlled through a gas train with all the necessary safeties and interlocks. A pilot gas or oil burner is provided for the purpose of gold start of the boiler. The provision can also be made to operate the boiler op oil /gas as stand-by fuel when BFG is not available. The high efficiency BFG fired steam boilers consists of following - 1) Refractory lined furnace for combustion of BFG. 2) Smoke tube type evaporator 3) Feed water pre-heater (economizer) 4) Super heater (optional) 5) The BFG train for regulations and modulation of blast furnace gas flow into the boiler. 6) The balanced draught system comprising of forced draught fan, dilution air fan, induced draft fan, gas ducting and draught control system. 7) Pilot oil / gas burner. 8) Instruments, controls and safeties for automatic and reliable operation of the boiler. Following advantages are achieved by the present invention 1) Refractory lined furnace provides high thermal inertia. Hence no supporting fuel is required to be burnt once the boiler achieve steady stage of operation and the flame can be sustained with only BFG as fuel. 2) Supporting fuel is required only during cold start, which can be achieved by a small pilot burner. 3) Due to high thermal inertia of refractory, there is no requirement of support fuel during automatic cut-in and cut-off operation of the boiler during partial load conditions. 4) The running cost of the boiler is reduced substantially as there is no requirement of support fuel. 5) The BFG, if available in sufficient quantities, can be completely utilized and no flaring in atmosphere is required. This not only reduces the running cost of the user but also reduces emission of green house gases. 6) Due to balanced draught system, the entire furnace is maintained under slightly negative pressure and hence there is no possibility of leakage of carbon monoxide (CO) into the atmosphere during operation of the boiler. 7) The combustion air required for combustion of BFG is circulated over the refractory lined furnace before, it enters the combustion chamber. This air not only provides effective cooling to the refractory, thereby improving its life, but also provides pre-heated combustion air for BFG to assist combustion. 8) Due to circulation of combustion air around the refractory lined furnace, minor leakages of BFG due to porosity of the refractory does not lead to leakage of BFG into the atmosphere. The BFG escaping the refractory mixes with the air which in turn enters the main combustion chamber. 9) The smoke tube evaporator is provided with the ferrules made of refractory materials to protect the tube to tube sheet welding joints from over heating due to hot gases entering into the furnace. 10) With economizer as a heat recovery unit, the thermal efficiency of the boiler can be as high as 88% + 2% on net calorific value of fuel. 11) To suit the specific requirement, the pilot burner can be designed to generate the full rajed capacity of the boiler, when BFG is not available as fuel i.e. the same burner can act as support burner as well as standby burner. 12) The dilution air fan is provided to restrict the flue gas temperature in the range of 1000 1200 Deg. C to protect the tube to tube sheet welding joints of the main eyaporator from over heating. 13) Large number of safeties and interlocks are provided to ensure safe, reliable and automatic operation of the boiler. Dated this 20tth day of June 2005. M.S.KHADILKAR (AGENT FOR APPLICANT)

Full Text

FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL SPECIFICATION
(See section 10 rule 13)
"HIGH EFFICIENCY BLAST FURNACE GAS FIRED STEAM BOILER"
ASHOK DATTATRAYA ATRE
'Pushpa heights', 1st floor,
Bibwevadi Corner,
PUINE- 411 037, MAHARASHTRASTATE, INDIA
Indian National
The following specification describes the nature of the invention

FIELD OF THE INVENTION
Present invention relates to high efficiency Blast Furnace Gas (BFG) Fired Steam Boiler.
PRIOR ART
In prior art the BFG Fired Boilers are either water tube type boilers or fire tube type boilers. The said BFG Fired Boilers are having forced draught arrangement. These BFG fired boilers need the support fuel in the form of either gas or oil to sustain the BFG flame. The requirement of support fuel is generally upto 30% of the total heat input required for the boiler. In these BFG fired boilers there is water walled furnace where radiant heat transfer takes place.
Taking into consideration the known BFG fired boilers following have dis-advantages-
1) BFG being a lean burning gas and furnace being water cooled in construction, the support fuel in the form of oil or gas is always required to be burnt to sustain the flame of BFG.
2) Due tQ absence of thermal inertia and BFG being a lean burning gas, during every restart, the boiler needs to be started with only supposing fuel till the boiler is stabilized and the furnace achieves the temperature of typically 700 Deg. C.
3) The requirement of support fuel increases the running cost of the boiler, as the cost of oil / gas is substantially higher compared to BFG. Even if BFG is available with the user in sufficient quantity
• and at low cost, the same can not be fully utilized due to the continuous requirement of support fuel.

4) Since the BFG can not be stored in large quantities, the excess BFG has to be flared and burnt in the atmosphere thereby resulting in substantial loss of heat. This also causes release of excessive Carbon dioxide (C02) gas into the atmosphere, which is considered as a green house gas responsible for global warming.
5) Additional investment in the form of support fuel burner, the fuel handling, storage and preparation is required.
6) The BFG contains approximately 20 to 25% by weight of Carbon monoxide (CO), which is a hazardous gas for human being who are exposed to the same and is also considered as the pollutant.
7) In case of even minor leakage from the furnace of the BFG fired boiler, there exists Tire, explosion and health hazard due to leakage of unburnt BFG in the atmosphere.
8) The conventional BFG fired boilers do not have heat recovery units and are hence less efficient.
SUMMARY OF THE INVENTION
The present invention aims to provide a high efficiency BFG fired steam boiler.
It is also the object of the present invention to provide the BFG fired boiler, which does not, require any support fuel except during cold start.
It is also the object of the present invention to overcome and eliminate the drawbacks and short falls of the prior art.
In the boiler of the present invention BFG is burnt in a hot refractory lined furnace. The air required for combustion of BFG is supplied by a forced draft

fan. A dilution air fan is also provided to maintain the flue gas temperature in the range of 1000 to 1200 Deg. C. The flue gases are passed through a fire tube boiler and steam is generated. The flue gases leaving the boiler at a temperature of 30Q to 400 degrees are passed through an economiser where feed water is preheated from 90 degrees to nearly saturation temperature. A superheater can also be provided as an optional device between boiler and economiser to suit the specific requirement. The furnace is maintained under slightly negative pressure by an induced draft fan. The steam generation and steam pressure is controlled through a stepless modulating control system. The flow of BFG into the boiler furnace is controlled through a gas train with all the necessary safeties and interlocks. A pilot gas or oil burner is provided for the purpose of gold start of the boiler. The provision can also be made to operate the boiler op oil /gas as stand-by fuel when BFG is not available.
The high efficiency BFG fired steam boilers consists of following -
1) Refractory lined furnace for combustion of BFG.
2) Smoke tube type evaporator
3) Feed water pre-heater (economizer)
4) Super heater (optional)
5) The BFG train for regulations and modulation of blast furnace gas flow into the boiler.
6) The balanced draught system comprising of forced draught fan, dilution air fan, induced draft fan, gas ducting and draught control system.
7) Pilot oil / gas burner.
8) Instruments, controls and safeties for automatic and reliable operation of the boiler.
Following advantages are achieved by the present invention
1) Refractory lined furnace provides high thermal inertia. Hence no supporting fuel is required to be burnt once the boiler achieve steady stage of operation and the flame can be sustained with only BFG as fuel.

2) Supporting fuel is required only during cold start, which can be achieved by a small pilot burner.
3) Due to high thermal inertia of refractory, there is no requirement of support fuel during automatic cut-in and cut-off operation of the boiler during partial load conditions.
4) The running cost of the boiler is reduced substantially as there is no requirement of support fuel.
5) The BFG, if available in sufficient quantities, can be completely utilized and no flaring in atmosphere is required. This not only reduces the running cost of the user but also reduces emission of green house gases.
6) Due to balanced draught system, the entire furnace is maintained under slightly negative pressure and hence there is no possibility of leakage of carbon monoxide (CO) into the atmosphere during operation of the boiler.
7) The combustion air required for combustion of BFG is circulated over the refractory lined furnace before, it enters the combustion chamber. This air not only provides effective cooling to the refractory, thereby improving its life, but also provides pre-heated combustion air for BFG to assist combustion.
8) Due to circulation of combustion air around the refractory lined furnace, minor leakages of BFG due to porosity of the refractory does not lead to leakage of BFG into the atmosphere. The BFG escaping the refractory mixes with the air which in turn enters the main combustion chamber.
9) The smoke tube evaporator is provided with the ferrules made of refractory materials to protect the tube to tube sheet welding joints from over heating due to hot gases entering into the furnace.

10) With economizer as a heat recovery unit, the thermal efficiency of the boiler can be as high as 88% + 2% on net calorific value of fuel.
11) To suit the specific requirement, the pilot burner can be designed to generate the full rajed capacity of the boiler, when BFG is not available as fuel i.e. the same burner can act as support burner as well as standby burner.
12) The dilution air fan is provided to restrict the flue gas temperature in the range of 1000 1200 Deg. C to protect the tube to tube sheet welding joints of the main eyaporator from over heating.
13) Large number of safeties and interlocks are provided to ensure safe, reliable and automatic operation of the boiler.

Dated this 20tth day of June 2005.
M.S.KHADILKAR
(AGENT FOR APPLICANT)

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=fd/Z61XqeAmx443tj2Lj9w==&loc=vsnutRQWHdTHa1EUofPtPQ==

« Previous Patent

Next Patent »

Patent Number

268513

Indian Patent Application Number

726/MUM/2005

PG Journal Number

36/2015

Publication Date

04-Sep-2015

Grant Date

31-Aug-2015

Date of Filing

21-Jun-2005

Name of Patentee

M/S TRANSPARENT ENERGY SYSTEMS PRIVATE LIMITED

Applicant Address

"PUSHPA HEIGHTS", 1ST FLOOR, BIBWEWADI CORNER, PUNE-411 037

Inventors:

#	Inventor's Name	Inventor's Address
1	ATRE ASHOK DATTATRAYA	PUSHPA HEIGHTS 1ST FLOOR, BIBWEWADI CORNER, PUNE-411 037,

PCT International Classification Number

F22B1/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA