Water Softening.


The presence of hardness salts (calcium and magnesium ions) in the make up

water softeners ukwater supplies to boilers, cooling and process waters can have a serious impact on their performance. Loss of heat transfer in boilers and poor cooling in re-circulating cooling systems results in an increase in both energy and water consumption, and an increase in operating costs.

The reliable Derwent standard range effectively removes these hardness salts and provides a valuable return on your investment.

Standard range:

Model 132 - Water Softeners up to 5m3/hr
Model 230/250 - Water Softeners up to 15m3/hr
Model 360/LF - Normal-Flow Water Softeners up to 20m3/hr
Model 360/HF - High-Flow Water Softeners up to 50m3/hr

water softeners ukThe standard range of units provides service flow rates from 0.65m3/hour to 50 m3/hour, and configuring the units in a duplex or triplex system will provide a further increase in design flow rates.

The water softeners have capacities which vary from 4.3m3 to 420m3 with a total input hardness level of 200ppm expressed as calcium carbonate.

The water softeners use the well-proven "Ion Exchange" process to convert the hard water ions of calcium and magnesium to sodium ions. The resultant water to service is typically less than 4 ppm total hardness.

Derwent Water Softeners have several different control options for instigating automatic plant regeneration:

  • Water meter control - regenerates after a specified volume of water by counting electrical pulses from the meter supplied with the softener
  • Time-clock control - regenerates at regular pre-set time intervals
  • Microprocessor Control System programmed for water hardness and flow rate

The softener vessels are of a seamless pressure vessel in GRP construction with moulded polyethylene inner and glass fibre reinforced wound outer shell for durability and long life.

The control valves are of the hydraulic double piston multiport type. Valves can be "top mount" or "side mount" entry for increased flow capacity.

The Derwent range of softening units have several options of salt/brining systems:

Single brine tank
Combined salt and brine tank for higher salt usage bulk salt systems.

Raw water break tanks, booster pump sets, level control systems and other ancillary equipment are available as standard.

Typical Boiler Uses: Boiler make up for low pressure boilers
Brewing/soft drinks
Blended for process waters in high hardness areas
Food processing
Cooling tower make-up