A. Ahlstrom Corporation

Foster Wheeler Energia Oy

Juhani M Isaksson

Folke Engstrom

Reijo J Kuivalainen

Timo Eriksson

Timo Hyppanen

Pekka Lehtonen

Steven J Provol

Teuvo Pulkkinen

Juha Palonen

Karukkampalayam M Sellakumar

Harry Ollila

Charles M Davis

Dave B Russell

Juha Tiensuu

Jari Koskinen

An apparatus for pneumatically conveying particulate material containing reaction products of a high pressure reactor from a supply vessel at a pressure of at least two bar to a receiving vessel at a considerably lower pressure. The apparatus includes a conveyor line attached to the supply vessel, a collecting vessel between the conveyor line and the receiving vessel, the collecting vessel including (i) a discharge conduit for the carrier gas, (ii) a device for controlling the discharge velocity of the carrier gas from the collecting vessel, and (iii) a device for controlling the pressure of the material collected in the collecting vessel, and a device for conveying the material directly from the collecting vessel to the receiving vessel essentially at the same pressure as is prevailing in the receiving vessel.

Method and apparatus for treating high pressure particulate material

Method and apparatus for recovering heat from solid material separated

The present invention relates to a combined cycle power plant comprising a air compressor providing pressurized air at pressure greater than 2 bar; a gas turbine means for driving the gas compressor means; a pressure vessel, circular in cross-section, connected to said air compressor and being capable of withstanding pressures greater than 2 bar; a pressurized circulating fluidized bed reactor enclosed by the pressure vessel, the circulating fluidized bed reactor having a reactor chamber, including substantially planar steam generation tube walls having a bottom section; means for leading hot combustion gases away from said reactor; one or more non-circular centrifugal separator(s) disposed within said pressure vessel being adapted to the reactor chamber and internal pressure vessel geometry for receiving and purifying hot combustion gases, having a gas outlet leading from said separator out of said pressure vessel; said centrifugal separator comprising a vertical vortex chamber having distinctly planar steam generation tube walls defining an interior gas space; and a bubbling fluidized bed heat exchanger chamber having distinctly planar steam generation tube walls defining an interior of said chamber, said chamber being connected to the bottom section of said reactor chamber; a heat recovery unit adapted to the gas turbine means for recovering heat from gas discharged therefrom; a steam generation cycle having a steam turbine, steam generation surfaces including said steam generation walls, and steam superheating surfaces.

Combined cycle power plant with circulating fluidized bed reactor

Either atmospheric pressure or superatmospheric pressure high temperature gases, as from a gasifier or other circulating fluidized bed reactor, are filtered using monolithic ceramic filter elements mounted in an advantageous manner within a vessel. At least one generally upright hollow chamber element is mounted by a tube plate within the vessel, and has at least one gas impervious side wall having a column of openings in it, an open end, and a closed end. Monolithic ceramic filter elements are mounted in the openings. A number of chamber elements are typically provided, e.g. mounted in a circular pattern, and/or mounted to extend downwardly from a top tube plate and upwardly from a bottom tube plate. Backflushing of the filter elements dislodges separated particles, which fall down to the bottom of the vessel and are removed through a central discharge opening.

Ceramic filtering of gases

In the filtering of high temperature (e.g. greater than 400.degree. C.) and high pressure (e.g. greater than 5 bar) gas--such as produced by pressurized fluidized bed combustion or gasification of coal--there is often a buildup of particles on the supporting elements for the filters, and on surrounding structures. This buildup of particles can damage the filter elements, or greatly reduce their effectiveness. This problem is avoided by periodically automatically cleaning the supporting and/or surrounding surfaces of the filters, as by directing high pressure gas streams at the supporting and/or surrounding surfaces. The filters may also be backflushed with compressed gas, as is conventional, at the same time as, or at different times than, when the supporting and/or surrounding structures are cleaned. Conduits with nozzles may be mounted directly on the supporting and/or surrounding surfaces and connected by a pipe with an automatically controlled valve to a source of high pressure fluid.

Eliminating ash bridging in ceramic filters

A method and apparatus are provided for operating a pressurized reactor system in order to precisely control the temperature within a pressure vessel in order to minimize condensation of corrosive materials from gases on the surfaces of the pressure vessel or contained circulating fluidized bed reactor, and to prevent the temperature of the components from reaching a detrimentally high level, while at the same time allowing quick heating of the pressure vessel interior volume during start-up. Superatmospheric pressure gas is introduced from the first conduit into the fluidized bed reactor and heat derived reactions such as combustion and gassification are maintained in the reactor. Gas is exhausted from the reactor and pressure vessel through a second conduit. Gas is circulated from one part of the inside volume to another to control the temperature of the inside volume, such as by passing the gas through an exterior conduit which has a heat exchanger, control valve, blower and compressor associated therewith, or by causing natural convection flow of circulating gas within one or more generally vertically extending gas passages entirely within the pressure vessel (and containing heat exchangers, flow rate control valves, or the like therein). Preferably, inert gas is provided as a circulating gas, and the inert gas may also be used in emergency shut-down situations. In emergency shut-down reaction gas being supplied to the reactor is cut off, while inert gas from the interior gas volume of the pressure vessel is introduced into the reactor.

Pressurized reactor system and a method of operating the same

Apparatus for cleaning high temperature, high pressure gases includes a pressure vessel, and a filtration unit within the pressure vessel. The filtration unit is adapted to communicate with a fluidized bed reactor gas outlet, and includes at least one dirty gas chamber housing a plurality of porous, ceramic filter tubes, and at least one clean gas chamber for receiving clean gas from the ceramic filter tubes. The dirty gas chamber includes a particle outlet for removing particles separated from the gas by the filter tubes. The porous ceramic filter tubes are horizontally oriented within the filtration unit or housing and mounted within water cooled walls of the housing. The fluidized bed reactor and associated cyclone separator may be located within the pressure vessel with the filtration unit, or located outside the pressure vessel and in communication with the filtration unit inside the pressure vessel.

Cleaning of high temperature high pressure (HTHP) gases

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine.

Pressurized fluidized bed reactor

Pressurized fluidized bed reactor and a method of operating the same

A pressurized fluidized bed reactor is provided utilizing a centrifugal separator having a gas space that is distinctly non-circular, preferably having a circularity of greater than or equal to 1.15. Most desirably the cyclone has a quadrate (e.g. square) cross-section, and is disposed inside of the pressure vessel along with the reactor chamber containing the fluidized bed. A number of ceramic candle or honeycomb filters may be provided connected to the gas outlet from the cyclone separator, within the pressure vessel, to filter the gas. This construction provides a minimized diameter of the pressure vessel because the reactor chamber with square cyclones is more compact than if conventional circular cross-section cyclones are employed. Also a second pressure vessel is not needed for the candle or honeycomb filters since there is sufficient room within the pressure vessel to accommodate them.

Centrifugal separator in pressure vessel

Filtering apparatus for filtering particles from high temperature (e.g. greater than 500 degrees C., and at a pressure of about 2-40 bar) gases includes a hollow upright vessel with at least one generally torodial shaped hollow clean gas chamber mounted within it. The gas chamber has a gas impervious peripheral wall with at least one ceramic or sintered metal filter mounted in an opening in the wall. Dirty gas flows through the filter(s) into the clean gas chamber, and then passes through a conduit to be ultimately discharged from the vessel. The torodial shaped chamber may be circular or polygonal (e.g. square) in plan, and circular or polygonal in cross-section; for example it can be constructed solely of flat plates.

Apparatus for filtering gases

Hot gases from a pressurized fluidized bed reactor system are purified. Under superatmospheric pressure conditions hot exhaust gases are passed through a particle separator, forming a flitrate cake on the surface of the separator, and a reducing agent--such as an NO.sub.x reducing agent (like ammonia), is introduced into the exhaust gases just prior to or just after particle separation. The retention time of the introduced reducing agent is enhanced by providing a low gas velocity (e.g. about 1-20 cm/s) during passage of the gas through the filtrate cake while at superatmospheric pressure. Separation takes place within a distinct pressure vessel the interior of which is at a pressure of about 2-100 bar, and-introduction of reducing agent can take place at multiple locations (one associated with each filter element in the pressure vessel), or at one or more locations just prior to passage of clean gas out of the pressure vessel (typically passed to a turbine).

Treating exhaust gas from a pressurized fluidized bed reaction system

A filter assembly for high temperature gases, such as from a circulating fluidized bed reactor, mounts monolithic ceramic filter elements within an upright vessel so that as the hot gas flows from the top toward the bottom of the vessel the gas passes through the elements with the clean gas discharged through a side wall of the vessel. The particle discharge is provided at the bottom of the vessel. Filter supporting elements within the vessel are cooled by cooling fluid, and pulse cleaning elements are associated with each of the filter elements. Flow directing elements within the vessel typically define a generally conical or pyramidal shaped flow directing surface. The flow directing elements may be refractory material bodies, or funnel shaped thin elements (e.g. of metal capable of withstanding high temperature), and may be mounted so that small amounts of movement are possible to accommodate thermal contraction or expansion.

Cylindrical filters in a tube sheet for cleaning high temperature gases

The grid plate is disposed between the fluidized bed reactor chamber and an underlying wind box and includes a plurality of nozzles for feeding fluidizing gas from the wind box into the reaction chamber. The nozzles are configured to afford different pressure drops across the grid such that with increasing pressure, additional nozzles are actuated in response to increasing pressure differences across the plate whereby fluidized bed start-up and steady state operating conditions may be facilitated.

Distributor plate in a fluidized bed reactor

A filter for filtration of particles from a hot gas flow. The filter has a filter chamber, in which a plurality of tubular filter elements and at least one support plate (provided with apertures for receipt of the filter elements) are disposed. A slot between the support plate and each filter element is sealed by disposing at least two seals which have the same diameter as the slot, and engage both the support plate and tubular filter. The seals preferably are flexible in the same way as a piston ring.

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Karhula, Finland

Juhani M Isaksson