Fluidized bed heat exchanger having separating drain and method of operation thereof

Claim 1

In a fluidized bed heat exchanger having a perforated support plate to support a bed of particulate material including a fuel material and an adsorbent material, means for introducing air through the perforations to fluidize said particulate material, means for starting combustion in said bed by which relatively heavy fuel ash particles are formed, means for introducing additional particulate material to said bed, and a drain having an inlet in said bed for discharging spent particulate material from said bed, the improvement comprising: separating means for retaining the adsorbent material particles in the fluidized bed and for permitting the relatively heavy fuel ash particles to fall into the drain, the separating means comprising means for providing a flow of air through said drain and into said bed sufficient to retain the adsorbent material particles in the fluidized bed, but insufficient to prevent the relatively heavy fuel ash particles from falling into the drain, the air flow providing means including an element connected to and annularly arranged with respect to the drain, the element having at least one perforation in communication with said drain, directing the flow of air through said drain, and means for allowing the relatively heavy fuel ash particles to pass.

Claim 8

A method of operating a fluidized bed having a perforated support plate and a drain comprising: supplying particulate material to the fluidized bed, including a fuel material and an adsorbent material; supplying fluidizing air to the fluidized bed through the perforated support plate; starting combustion in the fluidized bed by which relatively heavy fuel ash particles are formed; providing an annular element having a central aperture and at least one perforation in communication with said drain; and discharging the fuel ash particles through the drain while retaining the adsorbent material in the fluidized bed, said discharging step comprising providing a flow of air into said drain through said perforation, through said drain and into the fluidized bed sufficient to retain the adsorbent material in the fluidized bed, but insufficient to prevent the relatively heavy fuel ash particles from falling into said drain.

Claim 9

A method of operating a fluidized bed having a perforated support plate and a drain comprising: supplying particulate material to the fluidized bed, including a fuel material and an adsorbent material; supplying fluidizing air to the fluidized bed through the perforated support plate; starting combustion in the fluidized bed by which relatively heavy fuel ash particles are formed; providing an annular element having a central aperture and at least one perforation in communication with said drain; and discharging the fuel ash particles through the drain while retaining the adsorbent material in the fluidized bed, said discharging step comprising providing a flow of air into said drain through said perforation, through said drain and into the fluidized bed sufficient to retain the adsorbent material in the fluidized bed, but insufficient to prevent the relatively heavy fuel ash particles from falling into said drain.