Safety measures for gas recovery from the hottest

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The safety measures for converter gas recovery

are due to the fact that the error in the range of circulating torque is equal to the peak error minus the valley error. The generation of converter gas is intermittent and concentrated in the blowing period. Its composition is also different in different periods of the blowing period, and it is related to the operation of the recovery equipment and the recovery conditions of gas. The energy of each ton of steel converter gas is about 1million kJ. The world began to look for alternative solutions. The methods of recycling these energy include combustion method and unburned method. Unburned method is mainly developed abroad. First, we will introduce what is wedge load experiment to recover gas. There are three purification and dust removal methods for unburned method: one is Japan's og dust removal method, the other is Germany's Krupp company's minimum air volume dust removal method, and the third is France's IC open flue method. The converter steelmaking plant of Shijiazhuang Iron and Steel Co., Ltd. adopts the o g dust removal method to recover the gas. The gas was officially recovered on April 1st, 1998, and during the practice of more than a year, the safe and reliable operation was ensured, the resources were recovered, and the production cost was reduced

gas has three dangers: explosion, fire and poisoning. When the gas is not recycled and used properly, the above accidents may occur. It is of great significance to fully understand the characteristics of converter gas, master the recovery and use process of converter gas, be familiar with the functions of recovery system equipment, avoid all kinds of accidents and correctly handle the accidents that occur, so as to ensure personal safety, protect national property, reduce losses and reduce the scope of accidents

2. Characteristics of converter gas

the main components of the gas produced by the unburned method of converter are carbon monoxide and a small amount of hydrogen. The content of carbon monoxide in the recovered gas varies with different operating processes, generally 40% - 70%. Carbon monoxide is a colorless, slightly odorous gas with a gravity of 1 25kg/m3, slightly lighter than air. When the converter gas is mixed with air or oxygen (pure oxygen leaked from the oxygen gun), it will produce rapid combustion under specific conditions, which will suddenly increase the pressure in the facility and cause equipment damage and personal accidents. The commonly used gases in metallurgical enterprises are coke oven gas, blast furnace gas and converter gas, and the carbon monoxide content of converter gas is much higher than that of coke oven and blast furnace gas, and it is toxic, and the recovery operation process is discontinuous, which should especially attract our attention and attention

3. Safety assurance measures in the recovery process

(1) the prerequisite for the recovery of converter gas is to ensure the operation of the dust removal system in good condition and efficiently capture the dust particles in the converter flue gas, so that the quality of the gas can meet the needs of users. Converter flue gas purification and dust removal and gas recovery facilities are a set of closely connected and closely related systems. During production, the primary and secondary venturi pipes shall be supplied with water according to the values specified in the design and procedures to ensure the dust removal effect, the smoothness of the water spray pipeline and the atomization effect; The micro differential pressure between Erwen Rd valve plate and furnace mouth shall be automatically adjusted to ensure that the furnace mouth operates under micro positive pressure; Because it is wet dedusting, it is necessary to ensure that the dedusting system has a good dehydration effect, so that the fan and dedusting equipment can operate stably for a long time

(2) in order to ensure the reliability and safety of gas recovery and achieve good recovery purpose, necessary interlocking control, such as the interlocking of oxygen lance and smoke hood, should be considered in process design and actual operation; Automatic control and interlocking of recovery and dispersion switching; Interlock of hood micro differential pressure regulation system and smelting operation; Interlock between blower speed regulation and smelting operation; Interlock of high and low position of gas holder; Interlocking of water seal check valve and three-way valve, etc

(3) adopt computer to automatically control gas recovery, ensure the content of carbon monoxide in flue gas and improve the calorific value of recovered gas. Carbon monoxide and oxygen analyzers are installed in front of the three-way valve behind the fan to monitor the content of CO and O2 in the flue gas. The gas recovery conditions and data are input into the computer in the main control room in front of the boiler, and the computer controls the automatic recovery operation of the whole system. Oxygen content is an important parameter. In actual operation, it is necessary to control the oxygen content in the gas beyond the explosion limit. According to the requirements of the safety regulations for recovering converter gas, the oxygen content in the gas can be released when it is 2%, and can be recovered when it is 2%, so as to achieve the purpose of ensuring gas quality and safe recovery

(4) in the process control, the time of pre burning period and post burning period should be guaranteed. In the recovery system, the intermediate recovery method should be adopted. The pre burning and post burning flue gas with poor composition should be used to burn the pre and post burning flue gas. In the early stage, the flue gas should be used to wash the pipeline of the recovery system, so as to prevent a large amount of direct contact between gas and air in the system. In the later stage of blowing, the hood should be lifted to make the furnace gas burn as much as possible, Prevent the explosion caused by a large amount of air inhaled and mixed with unburned gas when the oxygen supply is stopped

(5) establish a three-point confirmation system. Converter gas recovery is a discontinuous process. The gas recovery post in the main control room in front of the furnace, the fan operator post in the converter fan room and the operation post of the gas holder are the three main working positions in the recovery system. The gas recovery post should closely cooperate with the furnace shaker in front of the furnace, understand and be familiar with the situation in front of the furnace, and confirm whether the smelting conditions meet the needs of recovery. The operator of the fan room is responsible for the connecting role of the recycling process, and should always pay close attention to the operation of the fan and the rotary water seal state of the three-way valve, and do a good job of patrol inspection. The gas holder operation post should balance the gas in and out of the gas holder to ensure the normal operation of the gas holder. In case of any problem affecting gas recovery in the fan room and gas holder, you should put the confirmation switch of your post in the state that gas recovery is not allowed. In the process of gas recovery, Heilongjiang organized 9 academicians of the Chinese Academy of engineering and 27 experts in the graphite industry to plan methods and measures for the expansion and strengthening of the graphite industry. Any post can control the action of the three-way valve to turn it from recovery to release. In actual operation, the three-point confirmation system and corresponding control operations effectively ensure that all recovery systems can be quickly and timely converted in case of special circumstances in the recovery process, so as to avoid accidents

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