We usually prevent equipment from working in wet conditions. In order to avoid corrosion, the wet maintenance of natural gas boilers will make people very confused. In fact, it is to fill the boiler with a protective aqueous solution to prevent the entry of oxygen in the air. In order to avoid or slow down the corrosion of the boiler due to the shutdown of the boiler, it protects the boiler instead. Here are several methods for you.
1. Hydrazine method
The hydrazine method makes the hydrazine of the oxygen scavenger into a protective aqueous solution and fills the natural gas boiler. When using hydrazine solution to protect the boiler, the protective chemical solution should be discharged into the ditch before starting. Because hydrazine is poisonous, it should be diluted in situ to ensure safety when it is discharged, and the boiler should be cleaned after discharge.
2. Amine solution method
The amine liquid procedure chance is that steel is not easily corroded by oxygen in water with a large amount of ammonia. Before the boiler is filled with ammonia, the stored water should be drained, and the stored water in the superheater should be pushed out with amine solution. The copper parts should be removed in advance, or the copper parts that may be in contact with the amine liquid should be isolated. Amines evaporate easily. Gu The water temperature should not be too high, but antifreeze measures should be taken in winter.
3. Maintain water pressure method
The method of maintaining water pressure is to use the feed water pump to fill the water vapor system of the boiler with boiler feed water (water except peroxygen), maintain the water pressure in the boiler above 0.15MPa, and close the valve to prevent air from infiltrating into the furnace. Pay attention to maintaining the pressure. When the pressure drops, the water pump can be used to top the pressure. This method is suitable for short-term shutdown of natural gas boilers or cold standby boilers, and the shutdown time does not exceed one week.
4. Keep steam pressure method
Use intermittent heating to keep the boiler steam pressure above 0.1~0.5MPa to prevent air from penetrating into the water and steam system of the boiler. This method is suitable for the hot standby state of the natural gas boiler. And the downtime should not exceed one week.
5. Alkaline method
The lye method adopts the method of adding lye to fill the boiler with water with a pH value above 10. It is said that the alkali used is sodium hydroxide or trisodium phosphate. This method is suitable for natural gas boilers that have been out of service for a long time.
6. Phosphate and nitrite mixture maintenance method
The working principle of this method is that sodium nitrite and trisodium phosphate solution form a protective film on the metal surface, thereby preventing the corrosion of the metal.
The above are several methods of wet maintenance of our natural gas boilers, and each method can adapt to boilers under different usage conditions in a wide range. It is believed that the above methods can also be adapted to various types of boilers, and we can apply these methods in various ranges.
We usually prevent equipment from working in wet conditions. In order to avoid corrosion, the wet maintenance of natural gas boilers will make people very confused. In fact, it is to fill the boiler with a protective aqueous solution to prevent the entry of oxygen in the air. In order to avoid or slow down the corrosion of the boiler due to the shutdown of the boiler, it protects the boiler instead. Here are several methods for you.
1. Hydrazine method
The hydrazine method makes the hydrazine of the oxygen scavenger into a protective aqueous solution and fills the natural gas boiler. When using hydrazine solution to protect the boiler, the protective chemical solution should be discharged into the ditch before starting. Because hydrazine is poisonous, it should be diluted in situ to ensure safety when it is discharged, and the boiler should be cleaned after discharge.
2. Amine solution method
The amine liquid procedure chance is that steel is not easily corroded by oxygen in water with a large amount of ammonia. Before the boiler is filled with ammonia, the stored water should be drained, and the stored water in the superheater should be pushed out with amine solution. The copper parts should be removed in advance, or the copper parts that may be in contact with the amine liquid should be isolated. Amines evaporate easily. Gu The water temperature should not be too high, but antifreeze measures should be taken in winter.
3. Maintain water pressure method
The method of maintaining water pressure is to use the feed water pump to fill the water vapor system of the boiler with boiler feed water (water except peroxygen), maintain the water pressure in the boiler above 0.15MPa, and close the valve to prevent air from infiltrating into the furnace. Pay attention to maintaining the pressure. When the pressure drops, the water pump can be used to top the pressure. This method is suitable for short-term shutdown of natural gas boilers or cold standby boilers, and the shutdown time does not exceed one week.
4. Keep steam pressure method
Use intermittent heating to keep the boiler steam pressure above 0.1~0.5MPa to prevent air from penetrating into the water and steam system of the boiler. This method is suitable for the hot standby state of the natural gas boiler. And the downtime should not exceed one week.
5. Alkaline method
The lye method adopts the method of adding lye to fill the boiler with water with a pH value above 10. It is said that the alkali used is sodium hydroxide or trisodium phosphate. This method is suitable for natural gas boilers that have been out of service for a long time.
6. Phosphate and nitrite mixture maintenance method
The working principle of this method is that sodium nitrite and trisodium phosphate solution form a protective film on the metal surface, thereby preventing the corrosion of the metal.
The above are several methods of wet maintenance of our natural gas boilers, and each method can adapt to boilers under different usage conditions in a wide range. It is believed that the above methods can also be adapted to various types of boilers, and we can apply these methods in various ranges.