What are the effects of scale on the boiler?

2021 / Sep / Wed

In boiler equipment, the formation of scale is the precipitation of solid substances from the supersaturated boiler water. A certain salt dissolved in the boiler water has a certain solubility. If the solubility limit is exceeded, the boiler water becomes a supersaturated solution of a certain salt. At this time, the excess part is dissolved out of the furnace water. So what are the effects of scale on the boiler? Are these effects positive or negative? The technical engineer of Zhengzhou Fangkuai Boiler Factory has something to say.


First of all, we must first understand what are the components of the scale in the boiler: 1. The fouling substances are mainly derived from the impurities contained in the feed water; 2. The impurities include the dissolved, colloidal or suspended matter in the feed water; 3. Common There are calcium carbonate, calcium sulfate, calcium silicate, magnesium hydroxide, etc.; 4. Under special circumstances, iron scale, oil scale or other organic scales may also be generated.

Secondly, it is necessary to have a certain understanding of the distribution law of scale in the boiler: 1. Generally there is secondary scale in the header; 2. The scale accumulated at the bottom of the drum is generally the scale that falls off the smoke pipe; 3. The formation near the water supply pipe The scale is generally dominated by carbonate salt; 4. The mixed scale of silicate or sulfate is usually generated in the water wall pipe; 5. When the water source is changed or the water treatment method is changed, a large amount of scale may fall off; 6. Boiler The scale is generally distributed on each heated surface; the scale formed on the non-heated surface is generally secondary scale.

For boiler equipment, the harm caused by scale is huge. Excessive scale will destroy the normal water circulation of the boiler, causing defects such as overheating, deformation, material deterioration, and cracks on the heating surface of the boiler. In severe cases, it will also reduce the thermal efficiency of the boiler, increase the production and equipment maintenance costs of the enterprise, and cause safety problems, causing personal injury and death.