Boiler Water Hardness Scale

Controlling boiler scale prevent scale and corrosion using chemicals inside the boiler.

Boiler water hardness scale.

Silica in boiler feedwater can be a problem. Evaporation in a boiler causes impurities to concentrate. Boiler scale is caused by impurities being precipitated out of the water directly on heat transfer surfaces or by suspended matter in water settling out on the metal and becoming hard and adherent. Water hardness is the measure of the amount of calcium and magnesium in the water.

Feedwater hardness usually ranges from 0 01 to 2 0 ppm but even water of this purity does not provide deposit free operation. A boiler that makes up 4000 gal day of water having 100 ppm of hardness has a potential of accumulating over 1000 pounds of scale per year. When untreated boiler water is heated this calcium and magnesium will precipitate from the solution to form hard scale on the tube surfaces. Water systems using groundwater as a source are concerned with water hardness since as water moves through soil and rock it dissolves small amounts of naturally occurring minerals and carries them into the groundwater supply water is a great solvent for calcium and magnesium so if the minerals are present in the soil around a water supply well hard water may be delivered to homes.

A serious loss of boiler efficiency and possibly boiler failure. Leading to local overheating. Preventing and minimizing hard water is one of the key hallmarks of boiler maintenance best practices hard water contains elements like magnesium and calcium that can build up in your boiler to form what s known as scaling. In addition hardness salts can precipitate from the boiler water to form sludge and eventually scale which deposits on the internal surfaces of the boiler.

Scaling mechanism is the exceeding of the. Hard water is one of the worst things that can happen to your industrial boiler. 73 control feed of chemicals that prevent scale. Most boiler systems have sodium zeolite softened or demineralized makeup water.

Alkalinity test in natural waters alkalinity is most commonly the result of bicarbonate and carbonate ions. In addition to the overheating and eventual failure of the boiler tubes due to scale efficiency is also decreased in the short term because of the scale s insulating effect on the heat transfer surfaces. Small amount of boiler water drawn off near surface. Always use a softener to ensure good boiler water quality.

Scale is a buildup of solid material formed on internal boiler surfaces. Therefore good internal boiler water treatment programs are necessary. Chemicals are designed to polish away small amounts of hardness that by passes the softener. Water hardness is the primary source of scale in boiler equipment.

This interferes with heat transfers and may cause hot spots. In treated waters alkalinity may also be contributed by hydroxide phosphate silicate and.