A device with a heat exchanger with a feed pipe for a medium leading from a medium inlet to the heat exchanger entrance and with a discharge pipe leading away from the heat exchanger exit is characterized in that it has a first bypass from the medium inlet to the discharge pipe and a second bypass from the feed pipe to the medium outlet and valves, so that the medium can also flow from the heat exchanger exit to the heat exchanger entrance.

Disclosed herein is an orifice plate comprising one or more plates having orifices disposed therein; the orifices being operative to permit the flow of solids from a moving bed heat exchanger to a solids flow control system; where the orifice plate is downstream of a tube bundle of the moving bed heat exchanger and upstream of the solids flow control system and wherein the orifice plate is operative to evenly distribute the flow of solids in the solids flow control system.

A process for combusting a high-moisture fuel to generate steam, the process comprising heating a high-moisture solid fuel while contacting the high-moisture solid fuel with an oxygen-depleted gas stream to produce a dried solid fuel and a moist oxygen-depleted gas stream; combusting the dried solid fuel with a combustion air stream to produce a combustion products stream; transferring heat to generate steam by indirect heat exchange with the combustion products stream; dividing the combustion products stream into a first portion and a second portion; transferring heat to the recirculating thermal fluid by indirect heat exchange with the first portion of the combustion products stream; and transferring heat to preheat the combustion air stream by indirect heat exchange with the second portion of the combustion products stream; and recombining the first portion of combustion products stream and the second portion of the combustion products stream.

A process for combusting a high-moisture fuel to generate steam, the process comprising heating a high-moisture solid fuel while contacting the high-moisture solid fuel with an oxygen-depleted gas stream to produce a dried solid fuel and a moist oxygen-depleted gas stream; combusting the dried solid fuel with a combustion air stream to produce a combustion products stream; transferring heat to generate steam by indirect heat exchange with the combustion products stream; dividing the combustion products stream into a first portion and a second portion; transferring heat to the recirculating thermal fluid by indirect heat exchange with the first portion of the combustion products stream; and transferring heat to preheat the combustion air stream by indirect heat exchange with the second portion of the combustion products stream; and recombining the first portion of combustion products stream and the second portion of the combustion products stream.

A heat exchanger tube block is stacked on another heat exchanger tube block in an upper-lower direction and connected to the another heat exchanger tube block. The heat exchanger tube block includes: a duct casing wherein exhaust gas containing dust flows in the upper-lower direction; a heat exchanger tube in the duct casing extends horizontally; an inlet header connects to the heat exchanger tube inlet; an outlet header connected to an outlet of the heat exchanger tube; and a vibration transmitting member transmitting vibration, applied to an upper end part of the vibration transmitting member, to the heat exchanger tube to make the dust accumulating on the heat exchanger tube fall. A lower end of the duct casing is formed horizontally. The inlet header is located higher than the lower end of the duct casing. The outlet header is located higher than the lower end of the duct casing.

A heat exchanger tube block is stacked on another heat exchanger tube block in an upper-lower direction and connected to the another heat exchanger tube block. The heat exchanger tube block includes: a duct casing wherein exhaust gas containing dust flows in the upper-lower direction; a heat exchanger tube in the duct casing extends horizontally; an inlet header connects to the heat exchanger tube inlet; an outlet header connected to an outlet of the heat exchanger tube; and a vibration transmitting member transmitting vibration, applied to an upper end part of the vibration transmitting member, to the heat exchanger tube to make the dust accumulating on the heat exchanger tube fall. A lower end of the duct casing is formed horizontally. The inlet header is located higher than the lower end of the duct casing. The outlet header is located higher than the lower end of the duct casing.