A stove including spiraling walls to create multiple vertical inlets, spiraling layers of spaces that can self-draw and self-heat the air from outside of the stove into the burn zone, and a rim that covers the top area of the spiraling walls and leaves an opening above the fire. From burning, a convection draft draws air from the side-environment of the stove through the vertical inlets to circulate in the spiraling layered space, and to supply to the fire horizontally. The circling of air will be heated by the fire through conduction and irradiation. This design enables extra heated air directly for an enhanced primary burn. The stove can include side walls of different profiles, e.g., straight, tilted and curved walls and different spiraling profiles of spiraling layered spaces, e.g., linear, exponential, and exponential-polynomial.

In an oxyfuel combustion boiler system, nitrogen gas separated by an air separation unit (ASU) is supplied as carrier gas to a pulverizer for drying and pulverization of fuel. A fluid mixture of the nitrogen gas from the pulverizer with pulverized fuel is supplied to a powder separation device where the pulverized fuel is separated. The separated pulverized fuel is mixed with the primary recirculated flue gas and supplied to a burner.

In an oxyfuel combustion boiler system, nitrogen gas separated by an air separation unit (ASU) is supplied as carrier gas to a pulverizer for drying and pulverization of fuel. A fluid mixture of the nitrogen gas from the pulverizer with pulverized fuel is supplied to a powder separation device where the pulverized fuel is separated. The separated pulverized fuel is mixed with the primary recirculated flue gas and supplied to a burner.

A smokeless firepit including a first bottom, a second bottom located above the first bottom, an inner wall extending upwardly from the second bottom, an outer wall extending upwardly from the first bottom, and a top plate connecting the inner and outer walls. The second bottom intakes primary combustion air and secondary combustion air. The secondary combustion air is configured to be received at a bottom of the outer wall, pass upward between the inner wall and the outer wall, and enter the burn chamber at a top of the inner wall underneath the top plate when the firepit is in the upright position and burning fuel.

A smokeless firepit including a first bottom, a second bottom located above the first bottom, an inner wall extending upwardly from the second bottom, an outer wall extending upwardly from the first bottom, and a top plate connecting the inner and outer walls. The second bottom intakes primary combustion air and secondary combustion air. The secondary combustion air is configured to be received at a bottom of the outer wall, pass upward between the inner wall and the outer wall, and enter the burn chamber at a top of the inner wall underneath the top plate when the firepit is in the upright position and burning fuel.

The present invention discloses a system for reducing ammonium bisulfate blockage in air preheaters of coal-fired power plants, comprising at least one powder, at least one powder injection device, and at least one powder storage device; Under the action of power, the powder enters the powder injection device from the powder storage device, and is then sprayed into the flue between the SCR denitrification reactor and the air preheater. The powder can selectively adsorb the precursor ammonia gas and/or sulfur trioxide of ammonium bisulfate, thereby reducing the generation of ammonium bisulfate, removing the ammonium bisulfate that causes blockage of the air preheater from the source, and reducing the deposition of ammonium bisulfate and/or ash on the heating surface of the air preheater. It has the characteristics of simple process, low equipment cost, low price of powder used, and low construction and operation costs.

A system for integrated removal of multiple pollutants includes an economizer, an air preheater, an electrostatic precipitator, a flue gas cooler and a low-temperature adsorber; the economizer has a shell side inlet for feeding boiler flue gas, a tube side inlet for feeding boiler feedwater, and a shell side outlet connected to a tube side inlet of the air preheater; the air preheater has a shell side inlet for introducing boiler intake air, and a tube side outlet connected to the electrostatic precipitator; the electrostatic precipitator has a dust discharge port at a bottom thereof and a flue gas outlet connected to the flue gas cooler; the flue gas cooler has a condensate outlet at a bottom thereof and a cold flue gas outlet at a top thereof and connected to the low-temperature adsorber; and the low-temperature adsorber has a purified flue gas outlet at a tail thereof.

A solid fuel burning cabinet circular heating appliance achieves improved emissions performance by providing a secondary air combustion path that preheats secondary combustion air. The firebox is selectively insulated such that areas of the firebox that do not preheat combustion air retain heat in the firebox while areas of the firebox that transfer heat into the combustion air transfer heat through the firebox into the incoming combustion air. The exhaust air path from the firebox to a chimney is also uninsulated to allow relatively quick heat transfer into a room in which the appliance is installed.

A solid fuel burning cabinet circular heating appliance achieves improved emissions performance by providing a secondary air combustion path that preheats secondary combustion air. The firebox is selectively insulated such that areas of the firebox that do not preheat combustion air retain heat in the firebox while areas of the firebox that transfer heat into the combustion air transfer heat through the firebox into the incoming combustion air. The exhaust air path from the firebox to a chimney is also uninsulated to allow relatively quick heat transfer into a room in which the appliance is installed.

Methods and combustion devices for reducing NOx formation upon combusting oxidant with fuel to form products of combustion are provided. Such methods and device may involve mixing at least first portions of at least two fluids selected from the group of oxidant, fuel and recirculated products of combustion in at least one first conduit to form a first mixture. The first mixture is subsequently supplied to a plurality of second conduits each in direct fluid communication with the first conduit. Motive energy is utilized to aspirate at least second portions of one or more fluids selected from the group of oxidant, fuel and recirculated products of combustion in at least one second conduit to form a combustible mixture that can be subsequently burned. In one embodiment, the motive energy may be provided or result from the first mixture.