Ways That Feed Water Tank Design Affects Boiler Performance

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Boiler efficiency depends on different factors, and boiler water treatment is one of the most critical ones. However, you cannot talk about adequate boiler water treatment without a thorough understanding of the feed water tank setup system. It is because feed water tanks perform several functions. Not only do the tanks act as reservoirs, but they also double up as condensate receivers and chemical injection points. Due to the multiple functions, feedwater tanks design and operation must ensure the boiler is consistently fed with properly treated water.  This article highlights how the feed water tank design affects water treatment quality.

Inadequate Feedwater Heating

Thermal shock is an enemy of a boiler system, and that is why feedwater must be heated first before it is directed to the boiler. It is possible with a steam sparger which uses steam from the boiler to heat the feed water tank. The temperature of the feed water tank has to be maintained at a certain range to help reduce oxygen levels, thereby making the feed tank heat faster. Therefore, ensuring that there is adequate heat supply and the control valve is in excellent operating condition is the first step towards a properly functioning feed water tank. If the two features aren't in good condition, then you will experience partial water heating in the feed water tank, which will consequently lead to thermal shock once the mildly heated water reaches the boiler. Therefore, it is vital to routinely keep track of the vent discharge against the temperature gauge for the cost-effective removal of oxygen and efficient heating.    

Make-up Rate of Cold Water

Ideally, the cold water entering the feed water tank should be approximately 50F and 80F (10C and 27C). Water at this temperature contains a significant amount of oxygen, and the amount of heat, whether continuous or intermittent, determines the rate at which oxygen dissolves during heating. As a general rule, the make-up rate should neither be fast or slow. If it is higher than optimal, cold water will reduce faster, thereby denying the steam system sufficient time to heat the water. On the other hand, if the rate is too slow, the boiler will use more energy.

Incorrect Feed Water Tank Pump Location

Installation of the feed water tank pump significantly affects how the boiler system operates. It is especially the case since feed water tanks are rarely adequately churned to promote uniform temperature and chemical composition in the water. If you use a feedwater tank whose pump is incorrectly positioned, it will undermine the heating process. The right location for a feedwater tank pump is, therefore, at the opposite end of the feed water tank where the make-up water enters. It allows enough time for the cold water in the feed water tank to adequately heat up before it enters the boiler.

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