Title of Invention

WATER COOLED HIGH TEMPERATURE BULK SOLID REMOVING SYSTEM

Abstract

A water cooled high temperature bulk solid removing system comprising a water cooled ash diverter; and a water cooled ash cooler in flow communication with said water cooled ash diverter; the said water cooled ash diverter comprises a distributor having a plurality of gas nozzles, and distributor held to a gas plenum, vertical limbs provided in said diverter so that the hot particulates rises and fluidizes in said limbs, an inclined pipe preferably disposed at an angle of 20 to 50° for receiving the particles to be delivered to said ash cooler, and a water jacket.

Full Text

FIELD OF INVENTION: This invention relates to integrated gasification based power generation; especially pressurized fluidized bed gasification based systems used for any grade of coals. BACKGROUND OF INVENTION Combined Cycle is 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 refractory lined pressurized 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 ejector using compressed air. Coal gas also called "fuel 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 the serially arranged cyclones. The coal gas at the exit of the cyclone is cooled in a Heat Recovery Boiler (HRB). The gas is further cooled in the gas cooler while superheating the saturated steam of HRB. Part of the superheated steam is utilized for gasification process and the rest expands in the steam turbine to generate electricity. The gas is further processed in the gas cleaning system and admitted to the gas turbine combustion chamber to generate electricity. During the gasification process, for a particular load, to maintain the bed height/inventory the bed ash is extracted from the bottom of the gasifier through water cooled high temperature bulk solid removing system. Maintaining the gasifier bed height is vital because it determines the fluidization velocity, better fluidization, better composition of fuel gas with adequate quantity and reduction in the over loading of equipment in the down stream of gas path with fly ash. In a pressurized fluidized bed gasifier the bed ash is removed by using rotary bucket type extractors through ash coolers. The ash coolers having number of smaller diameter tubes through which the required quantity of cold water is flowing and the ash is flowing between the tubes and gets cooled. Problems are encountered with bridging of ash above the buckets, and falling of larger size foreign materials like refractory pieces get locked in the bucket causing arresting rotation of bucket resulting to stop the extraction. OBJECTS OF THE INVENTION An object of this invention is to propose a water cooled high temperature bulk solid removing system, used to continuously or intermittently remove the bulk solids from the bed of a pressurized fluidized bed gasifier to a receiver vessel. Another object of this invention is to propose a water cooled high temperature bulk solid removing system, which maintains the bed height. Still another object of this invention is to propose a water cooled high temperature bulk solid removing system, which increases the life of down stream equipment in the fly ash path. Yet another object of this invention is to propose a water cooled high temperature bulk solid removing system, which no rotating parts. A further object of this invention is to propose a water cooled high temperature bulk solid removing system, which is simple to, operate. A still further object of this invention is to propose a water cooled high temperature bulk solid removing system, which is efficient. DESCRIPTION OF INVENTION: According to this invention there is provided a water cooled high temperature bulk solid removing system comprising a water cooled ash diverter; and a water cooled ash cooler in flow communication with said water cooled ash diverter; the said water cooled ash diverter comprises a distributor having a plurality of gas nozzles, and distributor held to a gas plenum, vertical limbs provided in said diverter so that the hot particulates rises and fluidizes in said limbs, an inclined pipe preferably disposed at an angle of 20 to 50° for receiving the particles to be delivered to said ash cooler, and a water jacket. The inclined pipe is preferably disposed at an angle of 20 to 50°C. The vertical limbs comprises a first and second limb, and having a height so as to allow an overflow from said second limb. The water cooled ash cooler comprises a distributor held to a plenum, a plurality of nozzles mounted on said distributor, an inclined tube for allowing the cooled particles to flow into an ash receiver. The inclined pipe provided with the cooler is disposed at an angle of 10 to 40°. A cooling water pipe is provided for said air cooler. DESCRIPTION WITH REFERENCE TO DRAWINGS Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawing and wherein: Fig. 1 shows the water cooled high temperature bulk solid removing system of the present invention. When controlled quantity of inert gas or clean coal gas at ambient temperature is admitted to the distributor 01 (refer Fig.l) welded with bubble cap nozzles 02 through the gas inlet pipe 03 and dual gas plenum 04 with slightly more than the system pressure, cause two different fluidization velocities in both the vertical, left and right limbs 05&06, the hot material in the ash diverter starts fluidizing and rising up in both the left and right vertical limbs. The incoming ash particles from gaisifier cause the particles in the right Iimb06, having a height of 0.6m to 1.2m to over flow into the ash cooler through the inclined pipe 07 having an angle 0 ranging from 20° to 50°. The ash diverter above the distributor is enclosed with cooling water jacket pipes 08,09&10. The height above the nozzles located in the middle of the distributor is ranging from 0.8d to 1.2d. This action continues until the fluidizing gas is admitted to the ash diverter. The high temperature bulk solid water cooled ash diverter with fluidizing condition acts as a seal, allowing the material to the water cooled ash cooler. Similarly adequate and controlled quantity of compressed air or clean gas is admitted to the ash cooler distributor 11 (see Fig 1) welded with bubble cap nozzles 12, through air or gas inlet pipe 13 and air/gas plenum 14, with slightly more than the ash diverter pressure. This makes the hot bulk solids in the ash cooler 16 to start fluidizing, cooling and rise up causing the cooled bulk solids to slide down into the ash receiver vessel through the inclined tube 15 having angle a ranging from 10° to 40°. The air and gas mixture is vented through vent pipe 17 and the ash cooler above the distributor is enclosed with cooling water jacket pipe 18. Cooling water inlet and outlet pipes, pressure, temperature measuring ports and ash drain pipes are also shown in the sketch. The invention has features in the fluidizing nozzle design, fluidizing medium and application in high pressure gasification system. WE CLAIM; 1. A water cooled high temperature bulk solid removing system comprising a water cooled ash diverter; and a water cooled ash cooler in flow communication with said water cooled ash diverter; the said water cooled ash diverter comprises a distributor having a plurality of gas nozzles, and distributor held to a gas plenum, vertical limbs provided in said diverter so that the hot particulates rises and fluidizes in said limbs, an inclined pipe preferably disposed at an angle of 20 to 50° for receiving the particles to be delivered to said ash cooler, and a water jacket. 2. A water cooled high temperature bulk solid removing system as claimed in claim 1 wherein vertical limbs comprises a first and second limb, and having a height between 0.6m to 1.2m so as to allow an overflow from said second limb. 3. A water cooled high temperature bulk solid removing system as claimed in claim 1 wherein water cooled ash cooler comprises a distributor held to a plenum, a plurality of nozzles mounted on said distributor, an inclined tube for allowing the cooled particles to flow into an ash receiver. 4. A water cooled high temperature bulk solid removing system as claimed in claim 1 wherein inclined pipe provided with the cooler is disposed at an angle of 10 to 40°. 5. A water cooled high temperature bulk solid removing system substantially as herein described and illustrated herein.

Documents:

1855-DEL-2004-Abstract-(10-10-2008).pdf

1855-del-2004-abstract.pdf

1855-DEL-2004-Claims-(10-10-2008).pdf

1855-del-2004-claims.pdf

1855-DEL-2004-Correspondence-Others-(10-10-2008).pdf

1855-del-2004-correspondence-others.pdf

1855-del-2004-correspondence-po.pdf

1855-DEL-2004-Description (Complete)-(10-10-2008).pdf

1855-del-2004-description (complete).pdf

1855-del-2004-drawings.pdf

1855-del-2004-form-1.pdf

1855-del-2004-form-18.pdf

1855-DEL-2004-Form-2-(10-10-2008).pdf

1855-del-2004-form-2.pdf

1855-DEL-2004-GPA-(10-10-2008).pdf

1855-DEL-2004-PA-(10-10-2008).pdf