Introduction of reforming scheme of bf gas boiler

Retrofit of burner

The boiler originally had 4 layers of 16 blast furnace gas burners, the first and fourth layers of burners were replaced by coke oven gas burners after the transformation. There were 8 burners in two layers, and the gas pipe, corresponding valve instrument accessories, ignition device, local control box and other accessories were replaced accordingly. The second and third layers of blast furnace gas burners were old.

Modification of heating surface

For coke oven gas calorific value is higher, coke oven gas boiler heating surface need less, the existing boiler heating surface is relatively big, will lead to the following conditions: (1) due to the chamber of a stove or furnace heating surface is too big, lead to a stove or furnace outlet flue gas temperature is reduced, superheater heat decreases, superheater steam temperature is lower than the original, can not reach the rated temperature, especially in low load condition is more serious, need to increase the superheater in the heated area. (2) Due to the large sulfur and water content in coke oven gas, too low exhaust temperature will cause serious low-temperature corrosion to the heating surface of the tail. Therefore, it is necessary to reduce the heating surface of the tail coal economizer and increase the exhaust temperature.

Reconnect the gas line

DN800 main pipe of coke oven gas shall be set up from the main network of the north ring of coke oven gas to boiler No. 5, butterfly valve, blind plate valve and corresponding metering device shall be installed, and branch pipe, four-angle pipeline and regulating valve shall be installed according to the design requirements of burner.

Modification effect

(1) After the transformation of coke oven gas, the boiler is in good running condition and all operating parameters meet the requirements, eliminating the adverse effect of high and direct mixing combustion mode of coke oven gas on boiler operation. The smoke exhaust temperature rose from the average 137℃ before the modification to the average 153℃, which greatly reduced the low-temperature corrosion of the heating surface at the end of the boiler.

(2) After the transformation, the surplus of coke oven gas in Xuangang was effectively digested, and the environmental pollution caused by the release of coke oven gas was eliminated.

(3) Reduce the amount of blast furnace gas burning, transfer to other boilers consumption, improve the steam load of other boilers, at the same time, improve the spontaneous electricity.

(4) It solves the bottleneck problem existing in the current all-fired BF gas boiler and can effectively maintain the normal operation of the turbo-blower in the case of the interruption of BF gas, thus creating conditions for the overall stability of Production in Xuangang.