MULTIPLE NOZZLE SPRAY DESUPERHEATER
WORKING PRINCIPLES
The MULTIPLE NOZZLE SPRAY (MNS) DESUPERHEATER valve regulates the amount of injection water by varying the number of injection nozzles in operation. This enables the water pressure to remain constant and an excellent and near uniform spray quality is achieved across the entire operation range. Control of nozzle opening is achieved by the positioning of a piston that is operated directly by an actuator mounted on the valve. This simple design means that no separate water injection control valve is necessary.
CONSTRUCTION
The MNS DESUPERHEATER is available in two basic executions:
HEAVY DUTY (fully forged body construction) for use on medium/high pressure
steam applications.
STANDARD DUTY (welded body construction) for use on medium/low pressure steam
applications.
The MNS DESUPERHEATER van be made from a wide range of construction materials. Pneumatic actuators are available from a wide variety of sub-suppliers. The units can also be equipped with “low-trust” electric actuators.
MULTIPLE NOZZLE HEADS
The MNS DESUPERHEATER may be equipped with a variety of spray heads. The uniform body threading accepts spray cylinder heads with a wide range of Kv (Cv) values. Standard configurations have either 6 or 9 equally sized spray nozzles, but combinations are available as the so called “mixed” spray heads. This feature enables the MNS DESUPERHEATER to be customized to the specific requirement.
ADVANTAGES
No steam side pressure drop:
A negligible steam side pressure drop makes this type suitable for those
applications where steam side pressure drop is limited, as in turbine exhausts.
No need for a separate water control valve:
Due to an integrated and directly actuated water injection control valve
no separate control valve is required.
High-tech nozzles:
Nozzles are constructed using the most up-to-date technology available, resulting
in a fine symmetrical hollow cone spray.
Large capacity range:
Due to the availability of a large variety of typical spray nozzles a large
injection water capacity range can be offered.