Title of Invention	"A WATER COOLED FLAT PLATE DISTRIBUTOR FOR UNIFORM DISTRIBUTION OF AIR OR A MIXTURE OF AIR AND STEAM IN HIGH TEMPERATURE FLUIDIZED BED GASIFICATION SYSTEM"
Abstract	This invention relates to a water cooled flat plate distributor for uniform distribution of air or a mixture of air and steam in high temperature fluidized bed gasification system comprising a cooling mean (01,02,03) for cooling the distributor, a mean (04 and 05) to introduce air or a mixture of air and steam uniformly to the distributor and a mean (07) for removal of bed ash form the distributor.

Title of Invention

"A WATER COOLED FLAT PLATE DISTRIBUTOR FOR UNIFORM DISTRIBUTION OF AIR OR A MIXTURE OF AIR AND STEAM IN HIGH TEMPERATURE FLUIDIZED BED GASIFICATION SYSTEM"

Abstract

This invention relates to a water cooled flat plate distributor for uniform distribution of air or a mixture of air and steam in high temperature fluidized bed gasification system comprising a cooling mean (01,02,03) for cooling the distributor, a mean (04 and 05) to introduce air or a mixture of air and steam uniformly to the distributor and a mean (07) for removal of bed ash form the distributor.

Full Text	FIELD OF INVENTION: The present invention relates to a water cooled flat plate distributor for uniform distribution of air or a mixture of air and steam in high temperature fluidized bed gasification system. BACKGROUND OF ART: Gasification of coal is utilized to generate electricity through integrated gasification and combined cycle operation using various grades of coals. During the gasification process, mixture of air and steam is admitted from the bottom of the gasifier, while coal with bed material which are crushed refractory particle of average size 0.7 mm. (such as Al 203) fluidized with adequate fluidization velocity with the help of bubble caps. Due to chemical reaction, coal gas is formed with specific chemical composition. The distributor helps to fluidize the bed and to mix coal rapidly and thoroughly. All the materials present above the distributor and called bed consisting of crushed coal, bed material, bed ash air and steam. STATE OF CURRENT ART: In pressurized fluidized bed gasifiers, air or mixture of air and steam is passed though a central pipe or a conical type distributor having a number of nozzles to cause fluidization. However, problems are encountered with formation of agglomerates due to non uniform fluidization and difficulty in bed ash removal. After completion of reaction the solid particles existing inside the gasifier are called bed ash. The novel distributor for high temperature fluidized bed system, comprises bubble cap nozzles and cooling water tubes, capable of achieving uniform flow distribution and one that minimizes the formation of agglomerates and rapid and thorough mixing of bed and it also helps for easy extraction of bed ash to maintain the bed height in pressurized fluidized bed gasification system. OBJECTS OF INVENTION: One of the objects of the present invention is to achieve uniform flow distribution of air or mixture of air and steam with adequate nozzle velocity especially for large gasifiers (diameter more than 1 meter) in a water cooled flat plate distributor system: A further object of this invention is to minimize the formation of agglomerate by rapid and thorough mixing of bed with the help of bubble caps nozzles and also to aid for easy extraction of bed ash. Detailed description of this invention is stated herein below with reference to the accompanying drawing. Fig-1. shows the elevation view of the invention. Fig-2. shows the plan view of the invention. Figures. 1 and 2 show the complete assembled elevation and plan view of water cooled flat plate distributor assembly and an enlarged view of air/steam nozzle welded with a tube according to the present invention. The novel water cooled flat plate distributor consists of a number of tubes (01) (Figures. 1 and 2) of diameter ranging form 40mm to 65mm., and a number of smaller size tubes (02) of diameter ranging form 20mm to 50mm., are welded with the bigger size tubes to complete the cooling water circuit. A plurality of flat fins (plate) (03) of thick and width varying from 5mm to 12mm, 75mm to 125mm respectively, are welded in between the tubes (01). A number of suitable size holes with a particular pitch are drilled in the flat fins (03). A number of specially designed air/steam nozzles (04) welded with a suitable size pipe (05), are positioned in the holes of the flat fins and welded to form a distributor. For ease of construction number of dummies (06) are seal welded suitably at the ends of the cooling water pipes (01) to ensure the desired cooling water circuit. A larger size pipe (07) of diameter ranging from 150mm to 300mm is welded at the center of the distributor for bed ash removal. The distributor is fixed/welded at the bottom of the gasifier and the water inlet and outlet connections are made. The water cooled flat plate distributor may be any shape circular or square or rectangular and any size. The air or air and steam mixture is introduced through the bottom of the water cooled flat plate distributor, coal is injected to the gasifier through ejector using compressed air. During the gasification process, the distributor creates uniform flow distribution of air and steam mixture and ensures uniform temperature distribution above the bed, which in turn enables to produce correct composition of fuel gas. It minimizes or avoids the formation of agglomerates by rapid and thorough mixing of the bed with the help of bubble cap air nozzles. It also holds the bed to a particular height with high temperature by allowing easy bed ash removal, it maintains uniform fluidization velocity, and the cooling arrangement enables the distributor to withstand high temperature. The invention takes care of the special requirements for gasification due to the properties of fluidizing medium (air and steam mixture), higher percentage of carbon in the fluidized bed and the application for higher pressure. WE CLAIM: 1. A water cooled flat plate distributor for uniform distribution of air or a mixture of air and steam in high temperature fluidized bed gasification system comprising a cooling mean (01,02,03) for cooling the distributor, a mean (04 and 05) to introduce air or a mixture of air and steam uniformly to the distributor and a mean (07) for removal of bed ash form the distributor. 2. A water cooled flat plate distributor as claimed in claim 1 wherein cooling mean consisting of a plurality of cooling water to tubes (01), a plurality of inter connecting tubes (02) and a plurality of water cooled flat plates (03). 3. A distributor as claimed in claim 2 wherein the water tube (01) bigger size tubes of diameter ranging from 40mm to 65mm and the connecting tubes (02) smaller size tubes of diameter ranging from 20mm to 50mm which are connected by welding with the bigger size tubes (01) in order to complete the cooling water circuit. 4. A distributor as claimed in claim 2 wherein the flat plates (03) having thickness and width varying, form 5mm to 12mm and 75mm to 12mm respectively, are connected by welding in between the tubes (01). 5. A distributor as claimed in claim 1 wherein the mean (04,05) to introduce air or a mixture of air and steam consisting of a plurality of specially designed bubble cap air/ steam nozzles (04) welded with a suitable size pipe (05) wherein the said nozzles (04) positioned with a particular pitch in the holes made by drilling on the plate (3). 6. A distributor as claimed in claim 1 wherein the water pipes (01) having a number of dummies (6) in the form of seal connected by welding at the ends of the pipes (01) in order to ensure the desired cooling water circuit. 7. A distributor as claimed in claim 1 wherein the mean for removal bed ash consisting of a larger size pipe (07) having diameter ranging form 150 mm to 300 mm connected by welding at the centre of the distributor.

Full Text

FIELD OF INVENTION:
The present invention relates to a water cooled flat plate distributor for uniform distribution of air or a mixture of air and steam in high temperature fluidized bed gasification system.
BACKGROUND OF ART:
Gasification of coal is utilized to generate electricity through integrated gasification and combined cycle operation using various grades of coals.
During the gasification process, mixture of air and steam is admitted from the bottom of the gasifier, while coal with bed material which are crushed refractory particle of average size 0.7 mm. (such as Al 203) fluidized with adequate fluidization velocity with the help of bubble caps. Due to chemical reaction, coal gas is formed with specific chemical composition. The distributor helps to fluidize the bed and to mix coal rapidly and thoroughly. All the materials present above the distributor and called bed consisting of crushed coal, bed material, bed ash air and steam.
STATE OF CURRENT ART:
In pressurized fluidized bed gasifiers, air or mixture of air and steam is passed though a central pipe or a conical type distributor having a number of nozzles to cause fluidization. However, problems are encountered with formation of agglomerates due to non uniform fluidization and difficulty in bed ash removal. After completion of reaction the solid particles existing inside the gasifier are called bed ash.
The novel distributor for high temperature fluidized bed system, comprises bubble cap nozzles and cooling water tubes, capable of achieving uniform flow distribution and one that minimizes the formation of agglomerates and rapid and thorough mixing of bed and it also helps for easy extraction of bed ash to maintain the bed height in pressurized fluidized bed gasification system.
OBJECTS OF INVENTION:
One of the objects of the present invention is to achieve uniform flow distribution of air or mixture of air and steam with adequate nozzle velocity especially for large gasifiers (diameter more than 1 meter) in a water cooled flat plate distributor system:
A further object of this invention is to minimize the formation of agglomerate by rapid and thorough mixing of bed with the help of bubble caps nozzles and also to aid for easy extraction of bed ash.
Detailed description of this invention is stated herein below with reference to the accompanying drawing.
Fig-1. shows the elevation view of the invention.
Fig-2. shows the plan view of the invention.
Figures. 1 and 2 show the complete assembled elevation and plan view of water cooled flat plate distributor assembly and an enlarged view of air/steam nozzle welded with a tube according to the present invention.
The novel water cooled flat plate distributor consists of a number of tubes (01) (Figures. 1 and 2) of diameter ranging form 40mm to 65mm., and a number of smaller size tubes (02) of diameter ranging form 20mm to 50mm., are welded with the bigger size tubes to complete the cooling water circuit. A plurality of flat fins (plate) (03) of thick and width varying from 5mm to 12mm, 75mm to 125mm respectively, are welded in between the tubes (01). A number of suitable size holes with a particular pitch are drilled in the flat fins (03). A number of specially designed air/steam nozzles (04) welded with a suitable size pipe (05), are positioned in the holes of the flat fins and welded to form a distributor. For ease of construction number of dummies (06) are seal welded suitably at the ends of the cooling water pipes (01) to ensure the desired cooling water circuit. A larger size pipe (07) of diameter ranging from 150mm to 300mm is welded at the center of the distributor for bed ash removal. The distributor is fixed/welded at the bottom of the gasifier and the water inlet and outlet connections are made.
The water cooled flat plate distributor may be any shape circular or square or rectangular and any size.
The air or air and steam mixture is introduced through the bottom of the water cooled flat plate distributor, coal is injected to the gasifier through ejector using compressed air.
During the gasification process, the distributor creates uniform flow distribution of air and steam mixture and ensures uniform temperature distribution above the bed, which in turn enables to produce correct composition of fuel gas. It minimizes or avoids the formation of agglomerates by rapid and thorough mixing of the bed with the help of bubble cap air nozzles. It also holds the bed to a particular height with high temperature by allowing easy bed ash removal, it maintains uniform fluidization velocity, and the cooling arrangement enables the distributor to withstand high temperature.
The invention takes care of the special requirements for gasification due to the properties of fluidizing medium (air and steam mixture), higher percentage of carbon in the fluidized bed and the application for higher pressure.

WE CLAIM:
1. A water cooled flat plate distributor for uniform distribution of air or a mixture of air and steam in high temperature fluidized bed gasification system comprising a cooling mean (01,02,03) for cooling the distributor, a mean (04 and 05) to introduce air or a mixture of air and steam uniformly to the distributor and a mean (07) for removal of bed ash form the distributor.
2. A water cooled flat plate distributor as claimed in claim 1 wherein cooling mean consisting of a plurality of cooling water to tubes (01), a plurality of inter connecting tubes (02) and a plurality of water cooled flat plates (03).

3. A distributor as claimed in claim 2 wherein the water tube (01) bigger size tubes of diameter ranging from 40mm to 65mm and the connecting tubes (02) smaller size tubes of diameter ranging from 20mm to 50mm which are connected by welding with the bigger size tubes (01) in order to complete the cooling water circuit.
4. A distributor as claimed in claim 2 wherein the flat plates (03) having thickness and width varying, form 5mm to 12mm and 75mm to 12mm respectively, are connected by welding in between the tubes (01).
5. A distributor as claimed in claim 1 wherein the mean (04,05) to introduce air or a mixture of air and steam consisting of a plurality of specially designed bubble cap air/ steam nozzles (04) welded with a suitable size pipe (05) wherein the said nozzles (04) positioned with a particular pitch in the holes made by drilling on the plate (3).

6. A distributor as claimed in claim 1 wherein the water pipes (01) having a number of dummies (6) in the form of seal connected by welding at the ends of the pipes (01) in order to ensure the desired cooling water circuit.
7. A distributor as claimed in claim 1 wherein the mean for removal bed ash consisting of a larger size pipe (07) having diameter ranging form 150 mm to 300 mm connected by welding at the centre of the distributor.

Documents:

2298-del-2004-abstract.pdf

2298-del-2004-claims.pdf

2298-del-2004-complete specification(granted).pdf

2298-del-2004-correspondence-others.pdf

2298-del-2004-correspondence-po.pdf

2298-del-2004-description (complete).pdf

2298-del-2004-drawings.pdf

2298-del-2004-form-1.pdf

2298-del-2004-form-19.pdf

2298-del-2004-form-2.pdf

2298-del-2004-form-3.pdf

2298-del-2004-form-4.pdf

2298-del-2004-gpa.pdf

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Patent Number

240767

Indian Patent Application Number

2298/DEL/2004

PG Journal Number

23/2010

Publication Date

04-Jun-2010

Grant Date

31-May-2010

Date of Filing

19-Nov-2004

Name of Patentee

BHARAT HEAVY ELECTRICLAS LIMITED

Applicant Address

BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	GOVINDASAMY VISWANATHAN AGM/CCDP	BHARAT HEAVY ELECTRICLAS LIMITED BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA.
2	RAJAMANNAR KANNAN SR. MANAGER/CCDP	BHARAT HEAVY ELECTRICLAS LIMITED BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA.
3	MOHAN SEL VAKUMAR SR. MANAGER/CCDP	BHARAT HEAVY ELECTRICLAS LIMITED BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA.
4	VENKATACHALAM PERIAKARUPPAN SR. PRODUCT ENGINEER/CCDP	BHARAT HEAVY ELECTRICLAS LIMITED BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA.
5	KRISHNAN THIRUMALAI	BHARAT HEAVY ELECTRICLAS LIMITED BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA.
6	DHANDA YUTHAM RAMAKRISHNAN SR. MANAGER/CCDP	BHARAT HEAVY ELECTRICLAS LIMITED BHEL HOUSE, SIRI FORT, NEW DELHI-110049, INDIA.

PCT International Classification Number

C10J 3/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA