DAM-H High-temp Multi-nozzle Desuperheater

High-temp multi-nozzle desuperheater with floating liner

Attemperation is the primary technique used for controlling the degree of superheat in a boiler or a Heat Recovery Steam Generator (HRSG). This is achieved through a controlled injection of water into the superheated steam. Attemperators are typically installed between superheaters and regulate the output temperature of the boiler / HRSG, as well as protect any secondary superheater pipes from damage due to excessive heat. The temperature controller for this attemperator (known as inter-stage) bases its temperature regulation on input from a temperature transmitter placed on the boiler / HRSG output. A secondary attemperator (called final stage) is often placed after the inter-stage temperature transmitter in order to prevent thermal damages to the steam turbine during start-up. The final stage attemperator ensures that the steam temperature upstream from the turbine does not rise too fast.

The DAM-H is a high performing ring style attemperator with a floating flow profiling liner for superior evaporation and performance.

The DAM-H is fitted with a floating liner (patent pending) which creates an optimal flow profile for desuperheating. Upstream from the water injection point the liner is fitted with holes that allow steam to flow between liner and outlet pipe. This reduces any temperature differential on both sides of the liner which would otherwise result in a high level of stress. The liner is fastened downstream from the water injection point using a clamp. The lack of welding on the liner allows it to move with the expansion of the material, making the design more resistant to cycling. Water is routed through the water pipe and introduced into the steam flow through a series of spring-loaded spray nozzles.