First salt and gas are removed from the water using a thermal process. All the makeup water is vaporised causing high concentrations of substances in the water that attack the steam boiler material to form deposits. By checking and limiting the build up of salt using chemical dosage, these problems can be avoided. ProMinent offers solutions for such applications.
Desalination of the makeup water
High cicles of concentration in the boiler water can only be achieved if makeup water with a low mineral content is available, providing low conductivity. Reverse osmosis and water softening systems are used.
Conditioning the makeup water
The boiler water is normally treated with the following chemicals:
- Hardness stabilisers
- Deflocculating agents
- Corrosion inhibitors
- Oxygen binding agents (e.g. hydrazine)
- pH value regulation (caustic soda, ammonia)
- Defoaming agents
Dosing of these chemicals into the makeup water tank is accomplished using dosing pumps
Blowdown control
Increase in salinity in the boiler water is monitored by conductivity. When the maximum value is reached, blowdown occurs. The blowdown valve is opened and water is removed from the boiler. Low-salt makeup water compensates for the loss in the boiler and reduces the boiler water conductivity. Part of the boiler water flow is guided across a cooler before reaching the conductivity probe, in order to avoid thermal overload of the probe. To reduce sample water losses, samples can be taken periodically making use of a motorised valve system.
ProMinent supplies the system components needed for these areas of application:
| Application |
ProMinent plants |
| Makeup water softening |
Dulcosmose® reverse osmosis systems |
|
Dosing of inhibitors:
- Hardness stabilisers
- Deflocculating agents
- Corrosion inhibitors
- Defoaming agents
|
Dosing systems for dosing of inhibitors |
| Oxygen binding agents |
Hydrazine decanting and dosing systems |
| Blowdown control |
Cool control blowdown control |
| Regulating the pH value |
DULCOMETER® and DULCOTEST® measurement, control and sensor technology | |