gas generatorWhat are the ash extraction methods? The wet ash extraction method is when the boiler ash is taken out of the water; the dry ash extraction method is when the ash is discharged from the ash box in a dry state.

       The dry ash extraction process is as follows: the ash is first scraped from around the grate to the upper ash hopper by a scraper. The lower ash hopper is composed of an ash box with an upper ash valve and a lower ash valve at the front and rear. During normal operation, the upper ash valve is opened, and the ash falls from the upper ash hopper into the lower ash hopper. When it is time to discharge the ash outwards , just close the upper ash valve and open the lower ash valve. At this time, the lower ash hopper is connected to the atmosphere, and the ash is discharged outside the furnace. Since draining the ash outside will pollute the environment, a water pipe or steam pipe is connected to the lower ash hopper to moisten the ash in the lower ash hopper and prevent fly ash from being discharged. Because the upper and lower ash valves often have ash and work in a humid environment, it is not easy to close the ash valves tightly, so the gas in the furnace sometimes leaks out of the furnace. Therefore, some units close both the upper and lower ash valves during production. Only when the ash is discharged, first open the upper ash valve, which will fall into the lower ash hopper, then open the upper ash valve, and open the lower ash valve to discharge. Repeat this cycle several times to basically drain out the ash. In addition to the original manual operation, the operation of the gate valve also includes pneumatic control and hydraulic control.

       In addition to the above-mentioned dry ash extraction and wet ash extraction methods, there is another method in which the gasification temperature is greater than the ash melting point during the gasification process, causing the ash to agglomerate during the gasification process. The agglomerated ash is discharged with water after being cooled by water. There is also the ash slag in the molten bed gasifier, which is also discharged as molten slag and is cooled by water into solid ash slag.