Title of Invention	HIGH TEMPERATURE BULK SOLID RECIRCULATOR FOR HIGH PRESSURE FLUIDIZED BED GASIFICATION SYSTEM
Abstract	Accordingly there is provided a high temperature bulk-solid recirculator adaptable to high pressure fluidized bed gasification systems, comprising; at least one bubble cap distributor for fluidizing bulk-solids, the distributor receiving a coal gas/air/inert gas/steam via an inlet pipe at a pressure higher than the operating pressure of the gasification system; a dual gas chamber collecting the bulk-solids from atleast one cyclone of the system; two fluidizing pipes disposed vertically in respect of the dual gas chamber for fluidizing the bulk-solids thereby causing transmittal of the fluidized material; a pipe angularly disposed and flowably inter connecting the atleast one cyclone and the fluidizing pipe for downlink transportation of the ash particles; and an inclined pipe disposed at an angle ranging from 40° to 80° with reference to the other one of the two fluidizing pipes for recycling back the ash particulates continuously to the gasification system, thereby causing the recirculator to operate as a unidirectional sealing means.

Title of Invention

HIGH TEMPERATURE BULK SOLID RECIRCULATOR FOR HIGH PRESSURE FLUIDIZED BED GASIFICATION SYSTEM

Abstract

Accordingly there is provided a high temperature bulk-solid recirculator adaptable to high pressure fluidized bed gasification systems, comprising; at least one bubble cap distributor for fluidizing bulk-solids, the distributor receiving a coal gas/air/inert gas/steam via an inlet pipe at a pressure higher than the operating pressure of the gasification system; a dual gas chamber collecting the bulk-solids from atleast one cyclone of the system; two fluidizing pipes disposed vertically in respect of the dual gas chamber for fluidizing the bulk-solids thereby causing transmittal of the fluidized material; a pipe angularly disposed and flowably inter connecting the atleast one cyclone and the fluidizing pipe for downlink transportation of the ash particles; and an inclined pipe disposed at an angle ranging from 40° to 80° with reference to the other one of the two fluidizing pipes for recycling back the ash particulates continuously to the gasification system, thereby causing the recirculator to operate as a unidirectional sealing means.

Full Text	FIELD OF INVENTION This invention relates to integrated gasification based power generation in high pressure fluidized bed gasification system using any grade of coals/bio mass. More particularly, the invention relates to a high temperature bulk-solid recirculator for high pressure fluidized bed gasification system. BACKGROUND OF ART Combined Cycle increasingly being used to generate electricity through integrated gasification. Such combined cycles are capable of using various grades of low calorific value and high ash content coals. In a fluidized bed gasifier the air and steam mixture is introduced through a distributor located at bottom of the gasifier. Coal is continuously injected to the gasifier through atleast one ejector using comprised air. Coal gas is produced due to the chemical reaction of coal with air and steam. The fly ash and unburnt carbon particles in fuel gas are separated by a plurality of cyclones disposed in series in the gasifier. The coal gas at the exit of the cyclone is cooled in a Heat Recovery Boiler (HRB). The gas is further cooled in a cooler simultaneously superheating the saturated steam of HRB. Part of the superheated steam is utilized for gasification process and the rest is caused to expand in the steam turbine to generate electricity. The gas is further processed in a gas cleaning system and admitted to a gas turbine combustion chamber to generate electricity. The collected fly ash having sizable amount of char/unburnt carbon which is recycled back to the gasifier through a non mechanical High temperature bulk solid recirculator to utilize the unburnt carbon in the fly ash. In typical pressurized fluidized bed gasifiers, the fly ash collected in a cyclone having considerable amount of unburnt carbon is recycled back to the gasifier through a fly ash cooler, a rotary bucket type extractor and an ejector use the compressed gas. A double shelled fly ash cooler generally is provided with a number of water tubes staggerly, arranged in the inner shell, wherein the required quantity of water is 1 admitted between the shells which flow through the tubes, and the ash flowing in between the tubes gets cooled. Problems are encountered in respect of bridging of the ash accumulated above the buckets of rotary extractor, and further respecting the larger size foreign materials like refractory pieces which get locked in the bucket causing an arresting of the rotation of the bucket leading to stoppage of extraction. Moreover, in this system considerable amount of heat is removed from the fly ash by the cooler and the cooled fly ash perforce recycled back to the gasifier at a lower temperature thus reducing the possibility of optimum burning/gasification of the recycled char. SUMMARY OF THE INVENTION Accordingly there is provided a high temperature bulk-solid recirculator adaptable to high pressure fluidized bed gasification systems, comprising; at least one bubble cap distributor for fluidizing bulk-solids, the distributor receiving a coal gas/air/inert gas/steam via an inlet pipe at a pressure higher than the operating pressure of the gasification system; a dual gas chamber collecting the bulk-solids from atleast one cyclone of the system; two fluidizing pipes disposed vertically in respect of the dual gas chamber for fluidizing the bulk-solids thereby causing transmittal of the fluidized material; a pipe angularly disposed and flowably inter connecting the atleast one cyclone and the fluidizing pipe for downlink transportation of the ash particles; and an inclined pipe disposed at an angle ranging from 40° to 80° with reference to the other one of the two fluidizing pipes for recycling back the ash particulates continuously to the gasification system, thereby causing the recirculator to operate as a unidirectional sealing means. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING Fig. - 1 Shows an elevational and side view of a high temperature bulk-solid recirculator of the present invention (without the gasifier). 2 DETAILED DESCRIPTION OF AN PREFERRED EMBODIMENT OF THE INVENTION In a fluidized bed bulk solid recirculator, when controlled quantity of clean coal gas/inert gas/air is admitted to a bubble cap distributor (01) through a gas inlet pipe (02) and a dual gas chamber (03) at a slightly more than the system pressure, fluidization velocities are generated in both left and right vertical limbs (04, 05), the diameter 'd' of the vertical limbs (04,05) ranging from 100mm 500mm. The bulk solids in both the limbs (04,05) start fludizing and rise upward. The ash particles collected in atleast one cyclone and flow through a pipe (06) having an angle a ranging from 40° to 80°. The ash particles in the other limb (05) over flow into the gasifier through an inclined pipe (07), having an angle G ranging from 40° to 80°. Above the bubble cap distributor (01), a plurality of cooling water jacket pipes (08,09,10 and 11) are configured for cooling the inner pipes (04,05,06 and 07). A plurality of fluidizing distributor nozzles are arranged in a middle portion of the distribution (01), for example at a height ranging from 0.8d to 1.2d. This process continues for the entire operation of the system and the unburnts in the fly ash are recycled back to the gasifier. The cooling water enters through an inlet pipes (12) and hot water exit from an outlet pipe (13). An auxiliary fresh coal injection pipe (14) enables fuel supplementing. Atleast one each inspection port (15) and pressure and temperature measuring port (16) is provided to said high temperature bulk solid recirculator. The high temperature bulk solid recirculator in a fluidizing condition acts as an one way seal, thereby allowing material flow to the gasifier, and preventing material/gas flow in the opposite direction. The invention has additional features in the fluidizing distributor nozzle design, water cooling arrangement and the application for higher pressure. 3 WE CLAIM 1. A high temperature bulk-solid recirculator adaptable to high pressure fluidized bed gasification systems, comprising: at least one bubble cap distributor (01) for fluidizing bulk-solids, the distributor (01) receiving a coal gas/inert gas/air/steam via inlet pipes (02) at a pressure higher than the operating pressure of the gasification system; a dual gas chamber (03) for admitting coal gas/inert gas/air/steam to the distributor (01) via inlet pipes (02); two fluidizing pipes (04,05) disposed vertically in respect of the dual gas chamber (03) for collecting the bulk solids from atleast one cyclone of the system, fluidizing the bulk-solids and thereby causing an upward transmittal of the fluidized material; a pipe (06) angularly disposed and flowably inter connecting the atleast one cyclone and the fluidizing pipe (04) for downlink transportion of the ash particles separated inat least one cyclone; and an inclined pipe (07) disposed at an angle ranging from 40° to 80° with reference to the other one (05)of the two fluidizing pipes (04,05) for recycling back the ash particulates continuously to the gasification system, thereby causing the recirculator to operate as a unidirectional sealing means. 2. The recirculator as claimed in claim 1, comprising a plurality of water jacket pipes (08,09,10,11) disposed, above the distributor (01) for cooling the inner pipes (04,05,06 and 07). 3. The recirculator as claimed in claim 1 or claim 2, wherein said plurality of water jacket pipes (08,09,10,11) have two inlet pipes (12) and one outlet pipe (13) for entry and exit of cooling water and hot water respectively. 4. The recirculator as claimed in claim 1, comprising an axilliary fresh coal injection pipe (13) for supplementing fuel supply. 5. The recirculator as claimed in claim 1, comprising atleast one each inspection port (15) and pressure and temperature measuring port (16). 6. The recirculator as claimed in claim 1, wherein the re-circulator is provided with a refractory lining. 7. A high temperature bulk-solid recirculator for high pressure fluidized bed gasification system as herein described and illustrated with the accompanying drawing. 5. 5 Dated this 22nd day of MARCH 2005. Accordingly there is provided a high temperature bulk-solid recirculator adaptable to high pressure fluidized bed gasification systems, comprising; at least one bubble cap distributor for fluidizing bulk-solids, the distributor receiving a coal gas/air/inert gas/steam via an inlet pipe at a pressure higher than the operating pressure of the gasification system; a dual gas chamber collecting the bulk-solids from atleast one cyclone of the system; two fluidizing pipes disposed vertically in respect of the dual gas chamber for fluidizing the bulk-solids thereby causing transmittal of the fluidized material; a pipe angularly disposed and flowably inter connecting the atleast one cyclone and the fluidizing pipe for downlink transportation of the ash particles; and an inclined pipe disposed at an angle ranging from 40° to 80° with reference to the other one of the two fluidizing pipes for recycling back the ash particulates continuously to the gasification system, thereby causing the recirculator to operate as a unidirectional sealing means.

Full Text

FIELD OF INVENTION
This invention relates to integrated gasification based power generation in high pressure fluidized bed gasification system using any grade of coals/bio mass. More particularly, the invention relates to a high temperature bulk-solid recirculator for high pressure fluidized bed gasification system.
BACKGROUND OF ART
Combined Cycle increasingly being used to generate electricity through integrated gasification. Such combined cycles are capable of using various grades of low calorific value and high ash content coals.
In a fluidized bed gasifier the air and steam mixture is introduced through a distributor located at bottom of the gasifier. Coal is continuously injected to the gasifier through atleast one ejector using comprised air. Coal gas is produced due to the chemical reaction of coal with air and steam. The fly ash and unburnt carbon particles in fuel gas are separated by a plurality of cyclones disposed in series in the gasifier. The coal gas at the exit of the cyclone is cooled in a Heat Recovery Boiler (HRB). The gas is further cooled in a cooler simultaneously superheating the saturated steam of HRB. Part of the superheated steam is utilized for gasification process and the rest is caused to expand in the steam turbine to generate electricity. The gas is further processed in a gas cleaning system and admitted to a gas turbine combustion chamber to generate electricity.
The collected fly ash having sizable amount of char/unburnt carbon which is recycled back to the gasifier through a non mechanical High temperature bulk solid recirculator to utilize the unburnt carbon in the fly ash.
In typical pressurized fluidized bed gasifiers, the fly ash collected in a cyclone having considerable amount of unburnt carbon is recycled back to the gasifier through a fly ash cooler, a rotary bucket type extractor and an ejector use the compressed gas. A double shelled fly ash cooler generally is provided with a number of water tubes staggerly, arranged in the inner shell, wherein the required quantity of water is
1

admitted between the shells which flow through the tubes, and the ash flowing in between the tubes gets cooled. Problems are encountered in respect of bridging of the ash accumulated above the buckets of rotary extractor, and further respecting the larger size foreign materials like refractory pieces which get locked in the bucket causing an arresting of the rotation of the bucket leading to stoppage of extraction. Moreover, in this system considerable amount of heat is removed from the fly ash by the cooler and the cooled fly ash perforce recycled back to the gasifier at a lower temperature thus reducing the possibility of optimum burning/gasification of the recycled char.
SUMMARY OF THE INVENTION
Accordingly there is provided a high temperature bulk-solid recirculator adaptable to high pressure fluidized bed gasification systems, comprising; at least one bubble cap distributor for fluidizing bulk-solids, the distributor receiving a coal gas/air/inert gas/steam via an inlet pipe at a pressure higher than the operating pressure of the gasification system; a dual gas chamber collecting the bulk-solids from atleast one cyclone of the system; two fluidizing pipes disposed vertically in respect of the dual gas chamber for fluidizing the bulk-solids thereby causing transmittal of the fluidized material; a pipe angularly disposed and flowably inter connecting the atleast one cyclone and the fluidizing pipe for downlink transportation of the ash particles; and an inclined pipe disposed at an angle ranging from 40° to 80° with reference to the other one of the two fluidizing pipes for recycling back the ash particulates continuously to the gasification system, thereby causing the recirculator to operate as a unidirectional sealing means.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Fig. - 1 Shows an elevational and side view of a high temperature bulk-solid recirculator of the present invention (without the gasifier).
2

DETAILED DESCRIPTION OF AN PREFERRED EMBODIMENT OF THE INVENTION
In a fluidized bed bulk solid recirculator, when controlled quantity of clean coal gas/inert gas/air is admitted to a bubble cap distributor (01) through a gas inlet pipe (02) and a dual gas chamber (03) at a slightly more than the system pressure, fluidization velocities are generated in both left and right vertical limbs (04, 05), the diameter 'd' of the vertical limbs (04,05) ranging from 100mm 500mm. The bulk solids in both the limbs (04,05) start fludizing and rise upward. The ash particles collected in atleast one cyclone and flow through a pipe (06) having an angle a ranging from 40° to 80°. The ash particles in the other limb (05) over flow into the gasifier through an inclined pipe (07), having an angle G ranging from 40° to 80°. Above the bubble cap distributor (01), a plurality of cooling water jacket pipes (08,09,10 and 11) are configured for cooling the inner pipes (04,05,06 and 07). A plurality of fluidizing distributor nozzles are arranged in a middle portion of the distribution (01), for example at a height ranging from 0.8d to 1.2d. This process continues for the entire operation of the system and the unburnts in the fly ash are recycled back to the gasifier. The cooling water enters through an inlet pipes (12) and hot water exit from an outlet pipe (13). An auxiliary fresh coal injection pipe (14) enables fuel supplementing. Atleast one each inspection port (15) and pressure and temperature measuring port (16) is provided to said high temperature bulk solid recirculator.
The high temperature bulk solid recirculator in a fluidizing condition acts as an one way seal, thereby allowing material flow to the gasifier, and preventing material/gas flow in the opposite direction. The invention has additional features in the fluidizing distributor nozzle design, water cooling arrangement and the application for higher pressure.
3

WE CLAIM
1. A high temperature bulk-solid recirculator adaptable to high pressure fluidized
bed gasification systems, comprising:
at least one bubble cap distributor (01) for fluidizing bulk-solids, the distributor (01) receiving a coal gas/inert gas/air/steam via inlet pipes (02) at a pressure higher than the operating pressure of the gasification system;
a dual gas chamber (03) for admitting coal gas/inert gas/air/steam to the distributor (01) via inlet pipes (02);

two fluidizing pipes (04,05) disposed vertically in respect of the dual gas chamber (03) for collecting the bulk solids from atleast one cyclone of the system, fluidizing the bulk-solids and thereby causing an upward transmittal of the fluidized material;
a pipe (06) angularly disposed and flowably inter connecting the
atleast one cyclone and the fluidizing pipe (04) for downlink transportion of the ash particles separated inat least one cyclone; and an inclined pipe (07) disposed at an angle ranging from 40° to 80°
with reference to the other one (05)of the two fluidizing pipes (04,05) for recycling back the ash particulates continuously to the
gasification system, thereby causing the recirculator to operate as a
unidirectional sealing means.
2. The recirculator as claimed in claim 1, comprising a plurality of water jacket
pipes (08,09,10,11) disposed, above the distributor (01) for cooling the inner
pipes (04,05,06 and 07).
3. The recirculator as claimed in claim 1 or claim 2, wherein said plurality of water
jacket pipes (08,09,10,11) have two inlet pipes (12) and one outlet pipe (13)
for entry and exit of cooling water and hot water respectively.
4. The recirculator as claimed in claim 1, comprising an axilliary fresh coal
injection pipe (13) for supplementing fuel supply.

5. The recirculator as claimed in claim 1, comprising atleast one each inspection port (15) and pressure and temperature measuring port (16).
6. The recirculator as claimed in claim 1, wherein the re-circulator is provided with a refractory lining.
7. A high temperature bulk-solid recirculator for high pressure fluidized bed gasification system as herein described and illustrated with the accompanying drawing.
5.

5
Dated this 22nd day of MARCH 2005.

Accordingly there is provided a high temperature bulk-solid recirculator adaptable to high pressure fluidized bed gasification systems, comprising; at least one bubble cap distributor for fluidizing bulk-solids, the distributor receiving a coal gas/air/inert gas/steam via an inlet pipe at a pressure higher than the operating pressure of the gasification system; a dual gas chamber collecting the bulk-solids from atleast one cyclone of the system; two fluidizing pipes disposed vertically in respect of the dual gas chamber for fluidizing the bulk-solids thereby causing transmittal of the fluidized material; a pipe angularly disposed and flowably inter connecting the atleast one cyclone and the fluidizing pipe for downlink transportation of the ash particles; and an inclined pipe disposed at an angle ranging from 40° to 80° with reference to the other one of the two fluidizing pipes for recycling back the ash particulates continuously to the gasification system, thereby causing the recirculator to operate as a unidirectional sealing means.

Documents:

00196-kol-2005-abstract.pdf

00196-kol-2005-claims.pdf

00196-kol-2005-correspondence-1.1.pdf

00196-kol-2005-correspondence.pdf

00196-kol-2005-description(complete).pdf

00196-kol-2005-drawings.pdf

00196-kol-2005-form-1.pdf

00196-kol-2005-form-18.pdf

00196-kol-2005-form-2.pdf

00196-kol-2005-form-3.pdf

196-KOL-2005-ABSTRACT 1.1.pdf

196-KOL-2005-CLAIMS 1.1.pdf

196-KOL-2005-CORRESPONDENCE 1.1.pdf

196-KOL-2005-CORRESPONDENCE 1.2.pdf

196-KOL-2005-DESCRIPTION (COMPLETE) 1.1.pdf

196-KOL-2005-FORM 6.pdf

196-KOL-2005-OTHERS.pdf

196-KOL-2005-PA.pdf

196-KOL-2005-PETITION UNDER RULE 137.pdf

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Patent Number

260544

Indian Patent Application Number

196/KOL/2005

PG Journal Number

19/2014

Publication Date

09-May-2014

Grant Date

06-May-2014

Date of Filing

22-Mar-2005

Name of Patentee

BHARAT HEAVY ELECTRICALS LIMITED

Applicant Address

REGIONAL OPERATIONS DIVISION (ROD), PLOT NO. 9/1 DJ BLOCK 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, HAVING ITS REGISTERED OFFICE AT BHEL HOUSE, SIRI FORT, NEW DELHI-110049

Inventors:

#	Inventor's Name	Inventor's Address
1	GOVINDASAMY VISWANATHAN	BHARAT HEAVY ELECTRICALS LIMITED (A GOVERNMENT OF INDIA UNDERTAKING), HPBP, TIRUCHIRAPALLI-620014.
2	KRISHNAN THIRUMALAL	BHARAT HEAVY ELECTRICALS LIMITED (A GOVERNMENT OF INDIA UNDERTAKING), HPBP, TIRUCHIRAPALLI-620014.
3	RAJAMANNAR KANNAN	BHARAT HEAVY ELECTRICALS LIMITED (A GOVERNMENT OF INDIA UNDERTAKING), HPBP, TIRUCHIRAPALLI-620014.
4	MOHAN SELVAKUMAR	BHARAT HEAVY ELECTRICALS LIMITED (A GOVERNMENT OF INDIA UNDERTAKING), HPBP, TIRUCHIRAPALLI-620014.
5	ACHIMUTHU RAJASEKARAN	BHARAT HEAVY ELECTRICALS LIMITED (A GOVERNMENT OF INDIA UNDERTAKING), HPBP, TIRUCHIRAPALLI-620014.
6	VENKATACHALAM PERIAKARUPPAN	BHARAT HEAVY ELECTRICALS LIMITED (A GOVERNMENT OF INDIA UNDERTAKING), HPBP, TIRUCHIRAPALLI-620014.

PCT International Classification Number

BO1J 8/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA