Indicator capable of rapidly determining hot water boiler feedwater hardness

Abstract

An indicator capable of rapidly determining hot water boiler feedwater hardness is characterized by being prepared by the following components in parts by weight: 50-55 parts of sodium chloride, 15-20 parts of sodium carbonate, 25-30 parts of sodium bicarbonate, 1.6-2.0 parts of disodium ethylene diaminetetraacetate and 0.18-0.20 part of eriochrome black T. The components of the indicator do not contain crystal water, therefore the indicator is stable in property and not prone to deliquescence and overcomes the defect that the disodium hydrogen phosphate and sodium dihydrogen phosphate contain lots of crystal water, thus being prone to deliquescence. The invention adopts the eriochrome black T as the color indicator, thus overcoming the defect that the color indicator is unstable when the ratios of acid chrome blue K and naphthol green B misfits each other when the KB indicator is adopted. The indicator is simple in production process, low in raw material cost and rapid and convenient in detection.

Description

technical field [0001] The invention relates to an indicator used for detecting the water quality hardness of boiler feed water when water outside the boiler is used for treatment. Background technique [0002] Boiler water treatment is a very important link in boiler operation. The quality of boiler feed water is of great importance to the safe and economical operation of the boiler, to prevent boiler explosion accidents, to prolong the service life of the boiler, to improve the heat transfer efficiency of the boiler and to save energy and reduce consumption. role. The water quality standard for industrial boilers GB / T1576-2008 stipulates that the total hardness of feed water for hot water boilers treated with chemical water outside the pot should not exceed 0.6mmol / L, and the feed water for steam boilers with steam pressure not greater than 2.5MPa treated with water outside the pot The total hardness should not be greater than 0.03mmol / L. Therefore, ensuring that the boi...

AI Technical Summary

Problems solved by technology

This method of hardness testing has many disadvantages. First, the liquid indicator is unstable and prone to failure after long-term storage, resulting in inaccurate measurement results.

Secondly, because this method does not add a buffer solution, the pH value of the solution is outside the color change range of the indicator, resulting in incorrect color development.

Third, when using this method to measure water hardness, since no complexometric titrant is added, the water hardness cannot be quantitatively measured, and only when the water hardness is zero, the solution can turn blue

The use of this rapid measuring agent requires the indicator to be dissolved in advance, and the pH value buffer contains moisture and is easy to get wet, and needs to be dried in advance, etc., which has the disadvantages of cumbersome production process and complicated process.

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