Schroedahl Type DKV Desuperheater to Control the Temperature of Superheated Steam or Gas
Product Features
- The spray water cooler (lance design) works with controlled nozzle technology for extremely effective steam cooling
- Spray head with integrated high-performance nozzles.
- Selectable control characteristics for precise temperature control
- A large water vapour pressure difference Delta p is permitted
- Excellent pressure atomization
- Tight shut-off, no leakage in closed position
- High control accuracy over the entire control range
- Tightly closing metallic seat. No leakage in closed position and thus no emptying of the cooling water lines possible.
- Contains the pressure injection nozzle, no additional control valves required
- High operational reliability through the use of simple components, minimal wear and tear
- Excellent control accuracy over the entire control range
Applications
- For steam cooling in power plant applications and for general gas cooling applications with
water injection
Nominal Diameter: DN 150-1200 / NPS 6-24
Pressure Class: PN 15-250 / Class 150-1500
Product Features
- The spray water cooler (lance design) works with controlled nozzle technology for extremely effective steam cooling
- Spray head with integrated high-performance nozzles.
- Selectable control characteristics for precise temperature control
- A large water vapour pressure difference Delta p is permitted
- Excellent pressure atomization
- Tight shut-off, no leakage in closed position
- High control accuracy over the entire control range
- Tightly closing metallic seat. No leakage in closed position and thus no emptying of the cooling water lines possible.
- Contains the pressure injection nozzle, no additional control valves required
- High operational reliability through the use of simple components, minimal wear and tear
- Excellent control accuracy over the entire control range
Applications
- For steam cooling in power plant applications and for general gas cooling applications with
water injection
Technical Data
| Nominal diameter | DN 150–1200 / NPS 6-24 |
| Pressure class | PN 15–250 / Class 150–1500 |
| Temperature (max.) |
Up to 650°C / 1200°F |
| Housing material | 1.0460 / A105 1.5415 1.7335 / A182F12CI.2 1.7383 / A182F22CI.3 1.4903 / A182F91 |
| Housing type | Forged |
| Media | Superheated Steam, Gas |
| Flanges | EN 1092-1, ASME B16.5, ISO 7005, JIS, JPI |
| Actuators | Pneumatic, Electric, Hydraulic, Handwheel (for manual operation) |
| Number of stages (max.) | 1 |
| Number of controlled stages (max.) | 1 |
| Operating range (max.) | 1:100 |
Function
Desuperheating (cooling) the steam can simply be achieved by injecting water into the steam flow. When injected, the water is evaporated by means of the desuperheater nozzles. Thereby the water absorbs heat and consequently the temperature of steam is reduced. The desuperheater type DKV is designed so that even at low injection water quantities an efficient spray of very fine droplets (mist) is obtained.
The nozzles in the sprayhead are designed to give the injection water a high velocity and a radial rotating movement under all conditions. This achieves a very fine atomization and consequently a rapid evaporation of the water.
The temperature sensor sends a control signal to the actuator, bringing the control spool into a stroke position corresponding to the characteristic curve. The cooling fluid is now admitted to the
injection nozzle and is accelareated at the nozzle insert.
In the nozzle chamber, the cooling medium is accelerated and rotated by means of a swirl insert, so that a spray of the finest atomization is produced when it exits into the steam line. Our high quality atomization of the cooling liquid is the basis of a good mixing from cooling fluid and steam at all load conditions. The position of the valve seat, just before the spray head, provides a tight shut-off in the closed position, so that dripping is prevented (the piston is lapped into the seat!). The small number of moving parts results in a reliable operation of the valve.
