The cooler is scaling up – how to fix it?
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The image below shows the cooler of the water separation device in a refinery cooling tower. The material of the heat exchange tubes is copper; due to the prolonged heat exchange between the hot fluid inside the tubes and the circulating water, a large amount of scale forms on the surface of these tubes, which reduces their efficiency in heat exchange. The structure of this heat exchanger is of the spray type. Circulating water is used to cool the required cooling tubes; however, due to prolonged operation, a considerable amount of scale accumulates on the surface of these heat exchange tubes. Generally, the scale that forms as a result of heat exchange between an open cooling tower and metal surfaces is carbonate scale. Such as CaCO3, MgCO3, which contain trace amounts of insoluble scale, etc. What methods can be used to solve this problem?
Chemical cleaning can be used to address the problem of scale. In particular, acidic cleaners such as hydrochloric acid are used to dissolve scale composed of calcium carbonate and magnesium carbonate; corrosion inhibitors and surfactants can also be employed to protect copper pipes and improve cleaning efficiency. At the same time, in daily operations, the formation of scale can be reduced by controlling the hardness and pH value of the circulating water, installing water softening equipment, and carrying out regular cleaning and maintenance. .
Currently, it relies on chemical addition in the circulating water and regular cleaning
The main thing is to reduce the components that cause scaling in the circulating water
This type of cooling tower, similar to an evaporative condenser, has a low water volume, high heat load, and rapid system concentration. During the process design phase, design institutes generally set requirements for the quality of the water entering the system (usually softened water or deionized water), but in terms of operation later on, most manufacturers use tap water as the make-up water. If we use conventional water treatment chemicals such as scale and corrosion inhibitors, it is necessary to control water quality parameters in accordance with national standards; this results in higher water consumption. To maintain stable water quality, a continuous discharge and replenishment system is generally employed. Judging from the picture you sent, the system is severely scaled up, and the cooling water is overly concentrated. Current handling approach: Based on the performance of our clients at present, my suggestion is that if water conservation is desired, concentrate it as much as possible; if scaling occurs, then clean it ； To slow down the rate of equipment scaling, water quality stabilization treatments or the addition of softened water should be carried out.
This condenser tube, which is similar to a cooling tower, has been used in our microwave scale-inhibition equipment on the cooling towers of central air conditioning systems before, and the results were quite good. But that central air conditioning cooling tower is relatively small, while this one is larger. I think it should have some effect, though I’m not sure if the results will be ideal. We can talk; WeChat: TigerPeng2014
The occurrence of severe scaling is first and foremost due to problems with water treatment: First, chemical cleaning using acids can be carried out by employing citric acid (which has a low acidity level and causes little corrosion to copper) or formic acid； Second, add copper corrosion inhibitors to reduce the corrosion of heat exchange equipment caused by acid adjustment ； Third, after the treatment is completed, select an appropriate corrosion and scale inhibitor; at the same time, control the pH of the water and regulate the calcium hardness of the make-up water, based on the local water quality conditions ； Fourth, control the water temperature, as high temperatures increase the likelihood of scale formation