In a petroleum residuum burning boiler including: a high-temperature reduction combustion chamber to which petroleum residuum fuel and primary combustion air are supplied and in which combustion is performed at a temperature of 1,300° C. or more and an air ratio of less than one; and a low-temperature oxidation combustion chamber which is connected to the high-temperature reduction combustion chamber and in which combustion is performed at a temperature of less than 1,300° C. and an air ratio of one or more, an assist gas is supplied to the high-temperature reduction combustion chamber, and unburned carbon of a combustion gas of the petroleum residuum fuel is gasified by a water gas reaction by using steam, generated by combustion of the assist gas, as a gasifying agent.

The invention relates to a system and process for hydrogen combustion for industrial or steam generation applications, and more particularly to a hydrogen combustion burner or retrofit kit combustion system and process using a primary pure hydrogen fuel source. The burner or retrofit kit combustion system and process may also use one or more secondary fuels, such as natural gas, methane, propane, or the like, to reduce emissions of CO.sub.2. Additionally, the inventive burner, system and process can use a flame temperature reducing fluid for lowering the bulk flame temperature of the burner to increase equipment life and decrease equipment failure. The flame temperature reducing fluid can include flue gas recirculation (FGR), water injection, steam injection, and a combination thereof.

Nozzles for delivering air into a combustion system of a boiler including an interchangeable nozzle barrel. Nozzle barrels can be easily replaced for maintenance or to change the size and flow velocity of the nozzles to optimize combustion performance. Nozzles may include converging sections with an arc, double arc's, bell shaped, or hyperbolic curves around the entire perimeter of the nozzle and optimized for delivery of air into the combustion system from ducting or from within a plenum.

A filter assembly structure and a water heater including the same are provided. The filter assembly structure includes a filter housing coupled to an inner surface of a base panel provided in a case of a water heater, and including a flow space formed together with the inner surface of the base panel and an entrance to communicate with the flow space, and a filter assembly detachably assembled with the filter housing and including an air filter to filter air introduced through an air inlet provided in the base panel. The filter assembly is provided in a slide structure and inserted into or separated from the filter housing through the entrance.

Nozzles for delivering air into a combustion system of a boiler including an interchangeable nozzle barrel. Nozzle barrels can be easily replaced for maintenance or to change the size and flow velocity of the nozzles to optimize combustion performance. Nozzles may include converging sections with an arc, double arc's, bell shaped, or hyperbolic curves around the entire perimeter of the nozzle and optimized for delivery of air into the combustion system from ducting or from within a plenum.

A forced air supply combustion apparatus sucks combustion air from an air supply port. An air filter for collecting foreign matters in the air is mounted on an air-supply-port-formed plate in an insertable and drawable manner. A filter frame is arranged to be brought into close contact with a peripheral part of the air supply port in a state of having mounted the air filter in position. The air-supply-port side edge parts are provided with retaining pieces to clamp a filter side frame part in the Z-axis direction against the side edge parts. A distance in the Z-axis direction between the air-supply-port side edge parts, and the retaining pieces is set larger than a dimension, in the Z-axis direction, of the filter side frame part, and is set smaller than a sum of the dimensions to be obtained by adding to said dimensions the projection height of the projections provided in a projecting manner.

A forced air supply combustion apparatus sucks combustion air from an air supply port. An air filter for collecting foreign matters in the air is mounted on an air-supply-port-formed plate in an insertable and drawable manner. A filter frame is arranged to be brought into close contact with a peripheral part of the air supply port in a state of having mounted the air filter in position. The air-supply-port side edge parts are provided with retaining pieces to clamp a filter side frame part in the Z-axis direction against the side edge parts. A distance in the Z-axis direction between the air-supply-port side edge parts, and the retaining pieces is set larger than a dimension, in the Z-axis direction, of the filter side frame part, and is set smaller than a sum of the dimensions to be obtained by adding to said dimensions the projection height of the projections provided in a projecting manner.

An impinging-type temperature uniformity device includes an outer case portion; and a temperature uniformizer provided in the outer case portion, spaced apart inwardly from an inner surface of the outer case portion and connected to the outer case portion, wherein the temperature uniformizer includes: a head portion provided in the outer case portion; and a body portion spaced apart inwardly from the inner surface of the outer case portion and including at least one through-hole.

The present invention relates to a combustion apparatus capable of reducing the combustion load of a burner and improving the combustion efficiency thereof. The combustion apparatus includes: a premixing chamber for premixing external air, introduced through an air supply inlet, with a combustion gas; a blower for supplying a mixed air premixed in the premixing chamber toward a burner; a combustion chamber for burning the mixed air by ignition of the burner; a heat exchanger for heat exchange with room heating water by using the combustion heat of the combustion chamber; an exhaust gas discharging part for discharging an exhaust gas having passed through the heat exchanger; and a duct through which the exhaust gas having passed through the exhaust gas discharging part is discharged outside, wherein the combustion apparatus includes an air intake preheater for heat exchange between the exhaust gas discharged to the duct through the exhaust gas discharging part and the air supplied to the premixing chamber through the air supply inlet, the air intake preheater including a channel-forming member in which a plurality of unit plates are stacked with a predetermined interval therebetween to form an exhaust gas channel and an air intake channel therein that are separated from each other, are adjacent to each other, and are alternately arranged.

An impinging-type temperature uniformity device includes an outer case portion; and a temperature uniformizer provided in the outer case portion, spaced apart inwardly from an inner surface of the outer case portion and connected to the outer case portion, wherein the temperature uniformizer includes: a head portion provided in the outer case portion; and a body portion spaced apart inwardly from the inner surface of the outer case portion and including at least one through-hole.