Pressure of steam generated by the waste pot of a shell furnace

The steam generated as a by-product in Shell furnaces accounts for about 15% of the total energy produced. Therefore, for a furnace with a capacity of 2000 tons per day, the amount of coal fed into the furnace is approximately 600 MWth, resulting in 90 MWth of steam being produced ； A furnace with a capacity of 3,000 tons per day consumes about 900 MWth of coal and generates 130 MWth of steam. The secondary steam pressure of Shell furnaces can include high pressure and medium pressure ； The temperature and flow rate of the steam are related to the composition of the heated surface. The corresponding power generation, if used in a combined cycle, can be estimated based on the respective power generation efficiency.

The steam pressure generated by the shell boiler’s waste boiler at full load is 5.5 MPa; the saturated steam temperature is around 300 degrees, while the superheated steam temperature is approximately 395 degrees. The steam that comes directly from the waste boiler is saturated steam, and this steam enters the E1306 unit of the gasification furnace once again to be heated further and turned into superheated steam. The steam production capacity of the waste boiler is generally around 100 T/D. The values mentioned above are based on the design specifications for Shell’s boilers with a coal feeding rate of 2000 T/D. In actual operation, the temperatures do not reach the required levels; they are lower. The main problem lies in insufficient heat transfer efficiency, which is caused by issues with the SGC section of the gasification furnace – too much ash present hinders heat exchange between steam and gas. Severe scaling on the membrane-type water walls also prevents the temperatures from reaching the desired levels.