How do remove scale and carbon deposits from diesel generators?

    The cooling system of the diesel generator will deposit a layer of yellow-white scale on the cooler and pipe wall after long-term use. Its main components are carbonates, some are sulfates, and some contain silicon. The scale reduces the cross-sectional area of ​​the pipeline, reduces the thermal conductivity, and reduces the cooling effect, which seriously affects the normal operation of the cooling system and needs to be cleaned regularly.

The method of removing scale can be chemical removal method, as follows:
1. Use 3%~5% trisodium phosphate solution to inject phosphate to remove the dirt after 10~12h, so that the scale will form salts that are easily soluble in water, and then rinse with clean water to remove residual alkali salts.
2. The lye removes limescale
    For the cast-iron engine cylinder head and water jacket, 750g of sodium hydroxide, 150g of kerosene, and 10L of water can be used to prepare a solution. After filtering, add it to the cooling system for 10-12h, then start the engine and run it at full speed for 15-20min, until the solution begins to boil. Drain the solution and wash again with water.
    Sodium silicate 15g can be used for aluminum cylinder heads and water jackets. 2g of liquid soap and 1L of water mixed solution, are injected into the cooling system to make the engine reach the normal working temperature; after running for 1 hour, drain the cleaning fluid and wash with water. The solution concentration of steel parts can be larger, about 10%-15% sodium hydroxide; the concentration of non-ferrous metal parts is lower, and about 2%-3% sodium hydroxide is sufficient.
3. Phosphoric acid, chromic acid, etc. are common methods to remove scale with pickling solution. Wash with 2.5% hydrochloric acid solution, mainly to generate CaCl2, MgCl2, and other salts that are easily soluble in water. The hydrochloric acid solution was added to the cooling system, and the solution was discharged after running at full speed for 1 h. Rinse again with clean water with more than 3 times the capacity of the cooling system. Take 50g/h3PO4.100ml (CrO3) chromic anhydride (CrO3) chromic anhydride (CrO3) 50g and 900ml of water, heat, soak for 30~60min, wash with 0.3% dichromate after washing, remove residual phosphorus and prevent corrosion. The scale of aluminum alloy parts should be cleaned with 5% concentration nitric acid solution or 10%~15% concentration acetic acid solution.

Removal method of carbon deposits in diesel generators: Most of the carbon deposits in the engine are accumulated on the valve piston and cylinder head. This carbon deposition affects the heat dissipation effect of some parts of the engine, makes the heat exchange conditions worse, affects its combustibility, and even causes the parts to overheat and cause cracks. At present, mechanical cleaning, chemical, electrolysis, and other methods are commonly used to remove carbon deposits from the unit.
1. The mechanical removal method is to remove carbon deposits with scrapers and wire brushes. To improve production efficiency, when using a wire brush, the electric drill can be driven to rotate by a flexible shaft. This method is simple and is often used by small maintenance units, but the efficiency is not high, the surface of the parts is easily damaged, and the carbon deposit is not easy to clean up.

2. Chemical method For the surface of some finishing parts, when the mechanical cleaning method cannot be used, the chemical method can be used. Immerse the part in sodium hydroxide. In a cleaning solution such as sodium carbonate, the temperature is 80-95 ℃, so that the grease is dissolved or emulsified, so that the carbon deposits are softened, take out after about 2~3 hours, and then use a brush to remove the carbon deposits, and use 0.1%~0.3% of dichromium Potassium acid hot water wash, and finally blow dry with compressed air.

3. The electrochemical method uses an alkaline solution as the electrolyte, the workpiece is joined with the cathode, and the carbon deposits are removed under the combined action of dehydrogenation in the chemical reaction. This method is more efficient, but it is necessary to master the standards of cleaning. For example, the specifications for removing carbon deposits by the valve electrochemical method are rough: voltage 6V, current density 6A/dm2, electrolysis temperature 135~145℃, electrolysis time 5-10min.