Material or article handling – Apparatus for moving material between zones having different... – Including trap chamber having horizontal axis of rotation
Patent
1995-04-06
1998-01-13
Keenan, James W.
Material or article handling
Apparatus for moving material between zones having different...
Including trap chamber having horizontal axis of rotation
414221, 406175, B65G 5366
Patent
active
057071985
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The invention relates to a method and a device for discharging particulate material from a container which is under pressure into a container at a lower pressure, usually atmospheric pressure. The invention is primarily intended for discharging residual products from a combustor.
BACKGROUND OF THE INVENTION
Discharging and handling solid residual products such as bed material, ash and slag products from a combustor operating at pressure levels up to 20 bar or more, for example a PFBC power plant, entail difficult problems. Lock hopper systems can be used, however the material is often greatly erosive, which entails considerable stresses on valves in the lock hopper systems and a rapid reduction of their sealing capacity. The service life is short and the maintenance costs high. The problems with discharge of solid material from a pressurized combustor are dealt with in a publication from Argonne National Laboratory, Argonne Ill., ANL/CEN/FE-81-3 entitled "Discharge and Handling of solids from Pressurized Fluidized Bed Combustors" by John E. Hanway and W. F. Podolski. European patent specification 0 108 505 describes a pressure-reducing discharge system without valves.
One object of the present invention is to provide a simplified discharge system for particulate material from a pressurized container with low service needs. The particulate material primarily relates to residual products in the form of ash and dust particles from a pressurized combustor with combustion in a fluidized bed. Another object is to achieve a more uniform discharge than in a lock hopper system. Still other objects are to reduce the number of valves and the gas consumption in discharge systems.
Swedish patent application 8803599-3 describes a proposal for a technical solution for the above-mentioned problems in connection with the discharge of particulate material (in the following also referred to by the term particles) and which, in addition, fulfils certain objects of the present invention. The Swedish specification discloses a device in which the reduction of pressure when discharging particles from a pressurized container is brought about by discharging the particles via a substantially vertical tube, wherein an upright column in the form of particles of discharged particulate material is built up in the tube. By allowing this particle column to become sufficiently high, the particle column gives rise to a pressure reduction in the accompanying gas from the pressure container as the gas is forced to flow through the upright particle column. If the particle column is sufficient high, a pressure reduction of the gas to atmospheric pressure can be obtained. Particulate material in the lowermost part of the particle column is discharged by means of a rotary vane feeder.
A disadvantage with pressure reduction in a particle column of the above known kind is that instability may arise. As an example, the discharge of the particulate material must be controlled by some form of control device. This will give the particle column different heights in the course of time. When the particle column is shorter, a higher pressure difference arises in the particle column along each section of the particle column, which results in a higher speed of the gas flow and a higher propelling force on the material in the particle column. Also the discharged material may influence the stability in the discharge device. If suddenly a larger percentage of coarser particles or fine particles cemented together into lumps are included in the particle column, gas paths may arise therein. This causes a more rapid gas flow which in turn influences the particle flow through the discharge device, whereby the pressure reduction which was to be achieved by the resistance of the particle column to gas flow does not function as intended.
SUMMARY OF THE INVENTION
The present invention relates to a method and a device for discharging particulate material from a container which is under pressure and located at a higher level to a storage means which
REFERENCES:
patent: 2684897 (1954-07-01), Diettrich
patent: 2834665 (1958-05-01), Rudolph et al.
patent: 4115070 (1978-09-01), Jukkola et al.
patent: 4205931 (1980-06-01), Singer et al.
patent: 4401402 (1983-08-01), Casperson
patent: 4459071 (1984-07-01), Norton
patent: 4530207 (1985-07-01), Brannstrom
patent: 4802796 (1989-02-01), Brannstrom
patent: 4860669 (1989-08-01), Collins, Jr. et al.
patent: 5066186 (1991-11-01), Shimada et al.
Hanway, Jr. et al., Discharge and Handling of Solids From Pressurized Fluidized-Bed Combustors, Oct. 1982, pp. 5-7 and 10-26.
Institute of Gas Technology, "Continuous Depressurization of Solids Using a Restricted Pipe Discharge System," Knowlton et al, No. 276, vol. 86, pp. 61-72; at least as early as Apr. 1992.
ABB Carbon AB
Keenan James W.
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