A method and apparatus for heating a furnace using a burner system having first and second burner assemblies, each including a burner and a regenerative media bed, the method including operating the first burner assembly in a firing mode and the second burner assembly in a regeneration mode, switching the first burner assembly from the firing mode to the regeneration mode and the second burner assembly from the regeneration mode to the firing mode, and operating the second burner assembly in the firing mode and the first burner assembly in the regeneration mode. The burner assembly in the firing mode may be fired in either a first operating mode where the burner is supplied with preheated low calorific fuel and the burner is supplied with oxidizing gas or a second operating mode where the burner is supplied with preheated oxidizing gas and the burner is supplied with high calorific fuel.

A method and apparatus for heating a furnace using a burner system having first and second burner assemblies, each including a burner and a regenerative media bed, the method including operating the first burner assembly in a firing mode and the second burner assembly in a regeneration mode, switching the first burner assembly from the firing mode to the regeneration mode and the second burner assembly from the regeneration mode to the firing mode, and operating the second burner assembly in the firing mode and the first burner assembly in the regeneration mode. The burner assembly in the firing mode may be fired in either a first operating mode where the burner is supplied with preheated low calorific fuel and the burner is supplied with oxidizing gas or a second operating mode where the burner is supplied with preheated oxidizing gas and the burner is supplied with high calorific fuel.

A heater is provided which has a heating chamber divided into a plurality of heating compartments, each operably to provide heat in a respective heating direction. The heater includes a respective heating element for each heating compartment, and the operation of at least one of the heating elements is independently controllable from the operation of at least one other heating element. There is also provided a gas burner assembly the heat and a control system controlling the operation of the heating element.

The burner preferably exclusively burns substantially explosible solid fuels and preferably has instant ON-OFF thermostat control, wastes no energy preheating the enclosure or external air supply, achieves stable combustion the moment the powder-air mix is ignited in our burner, is used in the upward vertical mode except for oil burner retrofits, burns a solid fuel in a single-phase regime as if it were a vaporized liquid or gas, is designed to complete combustion within the burner housing itself rather than in a large, high temperature furnace enclosure which it feeds, has an ultra-short residence time requirement, is a recycle consuming burner with self-contained management of initially unburned particles, is much smaller, simpler and lower cost, has a wider dynamic range/turndown ratio, is more efficient in combustion completeness and thermal efficiency, and operates with air-fuel mix approximately at the flame speed.

The burner preferably exclusively burns substantially explosible solid fuels and preferably has instant ON-OFF thermostat control, wastes no energy preheating the enclosure or external air supply, achieves stable combustion the moment the powder-air mix is ignited in our burner, is used in the upward vertical mode except for oil burner retrofits, burns a solid fuel in a single-phase regime as if it were a vaporized liquid or gas, is designed to complete combustion within the burner housing itself rather than in a large, high temperature furnace enclosure which it feeds, has an ultra-short residence time requirement, is a recycle consuming burner with self-contained management of initially unburned particles, is much smaller, simpler and lower cost, has a wider dynamic range/turndown ratio, is more efficient in combustion completeness and thermal efficiency, and operates with air-fuel mix approximately at the flame speed.

A controller is configured to set total stop in which operations of all of a plurality of water heaters are stopped when an abnormal condition of a fan or an abnormal condition in communication is sensed in any of the plurality of water heaters while at least one of the plurality of water heaters is operating. The controller is further configured not to set total stop when an abnormal condition of the fan or an abnormal condition in communication is sensed in at least one of the plurality of water heaters while a sensing element for sensing a backflow of an exhaust from an exhaust path assembly is connected to the controller.

A combustion device includes a combustion control section which controls combustion in the combustion device; a setting section operated to set information indicating whether or not a plurality of combustion devices are in a common vent discharge state; and a memory section which stores therein connection configurations with the other combustion control sections to which the combustion control section is communicatively connected, and the combustion control section determines whether or not the combustion control section can communicate with a linkage control section or the other combustion control sections, and inhibits combustion in the combustion device to which the combustion control section belongs, in a case where the combustion control section determines that the combustion control section cannot communicate with the linkage control section or at least one of the other combustion control sections and the common vent discharge state is set by the setting section.

A combustion device includes a combustion control section which controls combustion in the combustion device; a setting section operated to set information indicating whether or not a plurality of combustion devices are in a common vent discharge state; and a memory section which stores therein connection configurations with the other combustion control sections to which the combustion control section is communicatively connected, and the combustion control section determines whether or not the combustion control section can communicate with a linkage control section or the other combustion control sections, and inhibits combustion in the combustion device to which the combustion control section belongs, in a case where the combustion control section determines that the combustion control section cannot communicate with the linkage control section or at least one of the other combustion control sections and the common vent discharge state is set by the setting section.

A dual-bed system for preventing a boiler heating surface from being contaminated comprises a fluidized bed, a cyclone separator, a coal ash distributor, an ash-coal mixer, a lower pyrolysis bed, a return feeder and a cleaner, wherein the cyclone separator is connected with the upper lateral side of the fluidized bed; the inlet end of the coal ash distributor; the two outlets of the coal ash distributor are respectively connected with the inlet of the return feeder and the inlet of the ash-coal mixer; the outlet of the ash-coal mixer is connected with the inlet of the lower pyrolysis bed; the return feeder close to the lower lateral side of the fluidized bed is connected with the inlet on the lower lateral side of the fluidized bed; and the outlet of the cleaner is connected with the inlet on the lower lateral side of the fluidized bed.

A dual-bed system for preventing a boiler heating surface from being contaminated comprises a fluidized bed, a cyclone separator, a coal ash distributor, an ash-coal mixer, a lower pyrolysis bed, a return feeder and a cleaner, wherein the cyclone separator is connected with the upper lateral side of the fluidized bed; the inlet end of the coal ash distributor; the two outlets of the coal ash distributor are respectively connected with the inlet of the return feeder and the inlet of the ash-coal mixer; the outlet of the ash-coal mixer is connected with the inlet of the lower pyrolysis bed; the return feeder close to the lower lateral side of the fluidized bed is connected with the inlet on the lower lateral side of the fluidized bed; and the outlet of the cleaner is connected with the inlet on the lower lateral side of the fluidized bed.