A method and apparatus for cleaning a black liquor recovery boiler, where a furnace floor of the boiler is washed by mixing wash water in a wash water pool formed on the floor by at least one mixing device in the wash water pool, and by jetting wash water towards the floor by at least one pressure washer installed into the furnace through an opening in the furnace wall.

A rotary air preheater is provided, including: a rotor and a steam soot-blowing device arranged in a cold secondary air inlet channel of secondary air section. The steam soot-blowing device includes a steam sootblower, a first pipe communicating with the steam sootblower and extending in a radial direction of the rotor, and nozzle assemblies communicating with the first pipe. The nozzle assembly includes a first nozzle assembly and a second nozzle assembly, and the first nozzle assembly is located upstream of the second nozzle assembly in a rotational direction of the rotor. The first nozzle assembly includes a sprayer, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof. The second nozzle assembly includes at least one nozzle, and steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.

A rotary air preheater is provided, including: a rotor and a steam soot-blowing device arranged in a cold secondary air inlet channel of secondary air section. The steam soot-blowing device includes a steam sootblower, a first pipe communicating with the steam sootblower and extending in a radial direction of the rotor, and nozzle assemblies communicating with the first pipe. The nozzle assembly includes a first nozzle assembly and a second nozzle assembly, and the first nozzle assembly is located upstream of the second nozzle assembly in a rotational direction of the rotor. The first nozzle assembly includes a sprayer, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof. The second nozzle assembly includes at least one nozzle, and steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.

A biomass heating system for burning fuel in the form of pellets and/or wood chips is disclosed, the system comprising the following: a boiler with a combustion device, a heat exchanger with a plurality of boiler tubes, wherein the combustion device comprises: a combustion chamber with a rotating grate, with a primary combustion zone and with a secondary combustion zone; wherein the primary combustion zone is enclosed by a plurality of combustion chamber bricks laterally and by the rotating grate from below; wherein a plurality of secondary air nozzles is provided in the combustion chamber bricks; wherein the primary combustion zone and the secondary combustion zone are separated at the level of the secondary air nozzles; wherein the secondary combustion zone of the combustion chamber is fluidically connected to an inlet of the heat exchanger.

A closed-loop control system for intelligent soot blowing of a utility boiler is provided, including an intelligent soot blowing server, a distributed control system, a physical isolation device, a client and a heating surface soot blower group, where the intelligent soot blowing server communicates with the DCS via the physical isolation device, reads data from the DCS, and sends a soot blowing alarm signal or a soot blowing control signal to the DCS after processing the data; the client and the heating surface soot blower group establish communication links with the DCS separately; a program and a control flow of the closed-loop control system for intelligent soot blowing is developed; a time protection soot blowing flow for a heating surface of an air pre-heater is set in the control flow; a screen of the closed-loop control system for intelligent soot blowing is set up and installed in the DCS.

A closed-loop control system for intelligent soot blowing of a utility boiler is provided, including an intelligent soot blowing server, a distributed control system, a physical isolation device, a client and a heating surface soot blower group, where the intelligent soot blowing server communicates with the DCS via the physical isolation device, reads data from the DCS, and sends a soot blowing alarm signal or a soot blowing control signal to the DCS after processing the data; the client and the heating surface soot blower group establish communication links with the DCS separately; a program and a control flow of the closed-loop control system for intelligent soot blowing is developed; a time protection soot blowing flow for a heating surface of an air pre-heater is set in the control flow; a screen of the closed-loop control system for intelligent soot blowing is set up and installed in the DCS.

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.

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 rotary air preheater is provided, including: a rotor and a steam soot-blowing device arranged in a cold secondary air inlet channel of secondary air section. The steam soot-blowing device includes a steam sootblower, a first pipe communicating with the steam sootblower and extending in a radial direction of the rotor, and nozzle assemblies communicating with the first pipe. The nozzle assembly includes a first nozzle assembly and a second nozzle assembly, and the first nozzle assembly is located upstream of the second nozzle assembly in a rotational direction of the rotor. The first nozzle assembly includes a sprayer, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof. The second nozzle assembly includes at least one nozzle, and steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.

A rotary air preheater is provided, including: a rotor and a steam soot-blowing device arranged in a cold secondary air inlet channel of secondary air section. The steam soot-blowing device includes a steam sootblower, a first pipe communicating with the steam sootblower and extending in a radial direction of the rotor, and nozzle assemblies communicating with the first pipe. The nozzle assembly includes a first nozzle assembly and a second nozzle assembly, and the first nozzle assembly is located upstream of the second nozzle assembly in a rotational direction of the rotor. The first nozzle assembly includes a sprayer, and diameter of an inlet of the sprayer is smaller than diameter of an outlet thereof. The second nozzle assembly includes at least one nozzle, and steam jet velocity at the outlet of the sprayer is greatly smaller than steam jet velocity at an outlet of the nozzle.