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 combustion system includes a premix blower system and the premix blower system includes an additional air inlet with an adjustable opening which includes an additional reversibly pluggable air intake. The adjustable opening of the additional air inlet can be opened at higher elevations to compensate for thinner air.

A chemical recovery boilers is described in which the primary air system is reconfigured to provide aggressive charbed control and improved combustion in the lower furnace. The fewest number of primary air ports are used on two opposing walls to generate powerful air jets that penetrate across the boiler providing physical and thermal stability to the charbed while increasing the heat release and combustion stability in the lower furnace, increasing reduction efficiency, and lowering carryover and emissions. Various embodiments are described including operating strategies and multi-level black liquor injection.

A furnace system includes an air intake that includes a pipe portion and a seal component configured to couple with the pipe portion. The furnace system also includes an internal drain disposed internal to the air intake. The internal drain includes a trough configured to collect liquid flowing along an inner surface of the pipe portion. The internal drain also includes an opening in the trough configured to guide the liquid collected in the trough to a passage through the air intake to a location outside the air intake.

A furnace system includes an air intake that includes a pipe portion and a seal component configured to couple with the pipe portion. The furnace system also includes an internal drain disposed internal to the air intake. The internal drain includes a trough configured to collect liquid flowing along an inner surface of the pipe portion. The internal drain also includes an opening in the trough configured to guide the liquid collected in the trough to a passage through the air intake to a location outside the air intake.

A gas burner unit for a cooktop includes a spreader having a first side with a plurality of gas outlets and a second side opposite the first side and defining a portion of a fluid path. The spreader further defines a venturi in fluid communication with the gas outlets and extending away from the second side. The gas burner unit further includes an orifice holder having a protrusion defining an upwardly directed primary air inlet therethrough. The upwardly directed primary air inlet is in fluid communication with the fluid path associated with the spreader on a first end thereof and with the venturi on a second end thereof opposite the first end.

A gas burner unit for a cooktop includes a spreader having a first side with a plurality of gas outlets and a second side opposite the first side and defining a portion of a fluid path. The spreader further defines a venturi in fluid communication with the gas outlets and extending away from the second side. The gas burner unit further includes an orifice holder having a protrusion defining an upwardly directed primary air inlet therethrough. The upwardly directed primary air inlet is in fluid communication with the fluid path associated with the spreader on a first end thereof and with the venturi on a second end thereof opposite the first end.

Provided are a heat exchanger capable of cooling a shell plate and having good assemblability and a hot water apparatus having the same. A primary heat exchanger includes a heat exchanging portion, a shell plate, and a shell pipe portion. The shell plate surrounds the heat exchanging portion. The shell pipe portion is for cooling the shell plate. The shell plate includes a front surface portion and a main body portion. The main body portion is installed on the front surface portion and is formed by bending one sheet of plate into a U shape. The shell pipe portion is bent in a U shape along an inner surface of the main body portion and installed on the inner surface.

Provided are a heat exchanger capable of cooling a shell plate and having good assemblability and a hot water apparatus having the same. A primary heat exchanger includes a heat exchanging portion, a shell plate, and a shell pipe portion. The shell plate surrounds the heat exchanging portion. The shell pipe portion is for cooling the shell plate. The shell plate includes a front surface portion and a main body portion. The main body portion is installed on the front surface portion and is formed by bending one sheet of plate into a U shape. The shell pipe portion is bent in a U shape along an inner surface of the main body portion and installed on the inner surface.

A pyrolysis waste-to-energy conversion system has a muffle furnace housing a rotating retort drum within the furnace and having an inlet sleeve and an outlet sleeve extending through inlet and outlet ends of the muffle furnace. A rotating retort drum drive applies rotary drive to the inlet rotating retort drum sleeves and an in-feed auger is within a tube within the inlet sleeve. An out-feed auger is within a tube within the outlet sleeve and arranged to deliver char and pyrolysis syngas to a char processing system and a syngas processing system. The inlet sleeve and said outlet sleeve are arranged to provide a gas seal to prevent air ingress or syngas egress to and from the rotating retort drum. A gas cleaning system has a cracking tower arranged to retain inlet gas at an elevated temperature for a residence time, and a gas quench and scrubber system.