The coking process takes place in a coke oven that consists of heating coal to around 1000?1100 0C in the absence of oxygen to remove the volatile compounds. Once pushed out of the vessel the hot coke is then quenched with either water or air to cool it before storage or is transferred directly to the blast furnace for use in iron making.The volatile matter and moisture that are driven off during the coking process are collected,dried and cleaned. The resulting coke oven gas is recovered or transported for downstream use.
Critical Control of Process Gas
Coke oven flue gas: The gas produced in coking process mainly contains carbon monoxide(CO), methane(CH4) and hydrogen(H2). The presence of flammable and explosive gases requests a continuous monitoring of oxygen(O2) for safe operation.
To control efficiency of the desulfurization tower needs a reliable measurement of Hydrogen sulfide(H2S) before & after it.
Coke dry quenching (CDQ): The circulating gas used for cooling the red hot coke thereafter forms carbon monoxide(CO), carbon dioxide(CO2) and carries oxygen(O2), and possible hydrogen(H2). Continuous monitoring of above gases helps reduce burning loss and ensure safe operation.
Challenge of Instrumentation
Extremely harsh condition full of sticky tar and fine coke makes conventional extractive method very poor performance and massive maintenance.
FPI’s Laser Gas Analyzer (LGA) is seamlessly customized for this challenging application. The non-contact laser and sensor combined with continuous purge results in virtually maintenance free. Enhanced with FPI’s patented one-piece-half-open flange makes LGA the benchmark monitor for electrical tar precipitator, realizing minimum 70-80% laser transmittance given the extremely harsh condition. High-speed response (down to 1s) of the in-situ analyzer highlights its reliability for safety control. The extreme monochromaticity of laser spectrum ensures no cross-interference with all other gas species.
|Measuring Point||Target Gas||Measuring Range||Response Time||Mounting Type||Analyzer Model|
|1||Outlet of ETP||O2||0-2%/5%||<1s||cross duct||LGA-4100|
|4||CDQ circulating gas||O2||0-5%||<1s||cross duct||LGA-4100|
|5||Coke oven |
|* ‘CO+CO2’ means a combination of measuring the 2 components in single analyzer.|
NOTES: Listed are typical data FPI experienced and backed by field references. Alternate gases and ranges may be available or customizable on request.