ALL boilers and cooling towers need a water softener to help to prevent scale on heat transfer surfaces. It’s important to maintain these softeners to avoid equipment or machinery failures, and unnecessarily high energy costs.
“A water softener removes hard water minerals, like calcium and magnesium, which can cause scaling and damage in the boiler tubes,” explains Lionel Maasdorp, MD at Allmech – a leading South African manufacturer of boilers and supplier of water treatment components. “Cooling towers are another common application for industrial water softeners. They can operate much more efficiently with softened water. This can help to realise a drastic reduction in maintenance requirements, chemical feed quantity, and the volume of water required for operation. The correct balance of minerals of incoming water to industrial systems is essential to the proper operation and maintenance of expensive equipment.”
Whilst Maasdorp says water softeners are fairly low maintenance equipment, he recommends regular service visits are carried out to ensure that they are operating optimally.
How softeners work
Water softeners use a process called ion exchange to soften the incoming raw water. The process involves the transfer of unwanted hard ions, such as Calcium (Ca+) and Magnesium (Mg+), from the water to a solid substance that accepts these (the resin), and exchanges the ions for a desirable type of ion. Water softeners usually use sodium (Na+) as the exchange ion. Sodium ions are supplied from dissolved sodium chloride (salt). As hard water passes through a softener, the calcium and magnesium trade places with sodium ions.
“Every softener has a bed of resin, and this resin extracts the hardness in your water by capturing the calcium and magnesium ions that cause hardness,” explains Maasdorp. “After a while, the resin bed becomes saturated with these hardness-causing minerals, and there comes the need for ‘regeneration’.
Softener regeneration is simply the process of removing the minerals or ions absorbed from the resin beads in your water softener.”
Key maintenance considerations
When it comes to onsite water softener maintenance, it’s important to check the salt level in the brine tank regularly, and to use the right kind and quality of salt.
He advises ensuring the automated, semi-automated or manual softener control valve is operating correctly by regenerating the water softener as per its technical specifications.
A planned maintenance programme will ensure that problems are avoided or managed quickly as they arise. It is important to select the correct type of treatment plan to suit the operation’s needs. “At Allmech, we offer our customers a monthly maintenance service, which includes all the aspects required to keep their softeners functioning optimally,” says Maasdorp.
“The pre-treatment system is the most critical part of the total boiler water system, as it ensures water impurities are either removed or reduced to acceptable levels,” says Maasdorp. “Taking proper care of your softener is the best way to protect your investment in your boiler or cooling tower equipment.