Maintaining proper alkalinity of boiler water is very important, as it affects the safe operation and life of the boiler.Boiler water is usually alkaline. This characteristic is due to a variety of reasons. Regular testing and adjustment of boiler water alkalinity is an integral part of boiler maintenance and plays an important role in boiler protection and efficiency.At the same time, the relative alkalinity of boiler water is also an important water quality parameter, which is of great significance for evaluating the status of boiler water and adjusting water quality.This article will discuss in detail why boiler water is alkaline, what the relative alkalinity of boiler water means, and how to detect it.If you need detailed information and quotes on boiler water alkalinity tester, please contact customer service directly.
The main reasons why boiler water is alkaline are as follows:
1.Prevent oxygen corrosion: Boilers made of high-temperature and high-pressure materials are prone to corrosion, especially oxygen corrosion. Alkaline water can form a protective film to reduce the direct contact between oxygen and the metal surface, thereby slowing down the corrosion process. In order to prevent boiler pipes from being damaged by oxygen corrosion, ammonia is usually added to the boiler water. Ammonia is an alkaline substance that can effectively neutralize the acidic components in the water and prevent the formation of a corrosion layer on the metal surface.
2.Descaling treatment: The carbonates and hydroxides in alkaline water help dissolve the scale that has already formed, especially the hard scale mainly composed of calcium carbonate. In order to remove the scale in the boiler, phosphates (such as Na3PO4, Na2HPO4) are usually added for treatment. These phosphates are alkaline after hydrolysis in water, which helps prevent the precipitation of calcium and magnesium ions, thus reducing the impact of scale on heat transfer efficiency and improving boiler efficiency.
3.Raw water quality: The raw water in some areas contains relatively high alkaline substances, such as carbonates, which further react in the boiler, causing the boiler water to become alkaline.
The relative alkalinity of boiler water refers to the ratio of free NaOH to dissolved solids in boiler water. This parameter is used to evaluate the relative content of alkaline substances in boiler water and is of great significance for boiler corrosion and scale prevention.The higher the relative alkalinity, the higher the content of alkaline substances in the boiler water, and the stronger the protective effect on metals, but too high alkalinity may also lead to other problems such as salt deposition and scaling.
The following methods are mainly used to detect the relative alkalinity of boiler water:
1.Phenolphthalein indicator method: Phenolphthalein is used as an indicator to determine the content of alkaline substances by measuring the change in the pH value of boiler water. Phenolphthalein presents different colors at different pH values. The higher the pH value, the lighter the color, which can indirectly reflect the content of alkaline substances.
2.Ion selective electrode method: The concentration of specific ions (such as hydroxide ions) in water is measured by ion selective electrodes to calculate the alkalinity of boiler water. This method is based on the selective adsorption of specific ions by the liquid membrane in the electrode to generate a potential signal, and the ion concentration is obtained by measuring the size of the potential signal.
Boiler water is alkaline mainly to prevent oxygen corrosion and descaling. At the same time, some raw water itself contains alkaline substances. The relative alkalinity of boiler water is an important indicator for evaluating the state of boiler water and is of great significance for boiler corrosion and scale prevention.The relative alkalinity of boiler water can be accurately measured through detection methods such as the phenolphthalein indicator method and the ion selective electrode method, providing a basis for the adjustment and optimization of boiler water quality.In practical applications, the relative alkalinity of boiler water should be tested regularly, and the water quality should be adjusted in time according to the test results to ensure the safe operation and efficient use of the boiler. If you need detailed information and quotes on boiler water alkalinity testers, please contact customer service directly.
