Safety measures for hot work construction of negat

Safety measures for hot work construction of negative pressure gas pipeline in front of the blower

in view of the collapse of the upper part of the negative pressure gas pipeline in front of the gas blower, which has become a hidden danger seriously threatening safety production, the maintenance plan was formulated, and the corresponding safety measures for hot work construction were formulated, and the maintenance task was safely completed without affecting the normal transmission of gas

1 preface

the second recovery workshop of Masteel coal coking company is a large-scale continuous chemical workshop with a coke production scale of 2million T/A. The designed gas processing capacity is 129000 m3/h, and the annual recovery of coal tar is 100000 tons, light benzene is 28000 tons, and sulfur is 3200 tons

in 2004, the upper part of the bypass negative pressure gas pipeline of the DN1200 electric dust catcher (hereinafter referred to as the electric dust catcher) in the former series of gas blowers suddenly collapsed. After inspection, it was found that the pipeline was seriously corroded because it was not used for a long time, and the partial wall thickness of the upper part of the pipeline was less than 1mm. Later, the temporary treatment measures of plugging insulation cotton at the rupture of the pipeline and wrapping white iron sheet outside were taken. Once the negative pressure pipeline is corroded and broken, it will absorb a lot of air, and the consequences will be unimaginable. The pipeline has become a major hidden danger threatening safety production

2 scheme formulation

in order to completely solve the hidden danger without affecting the normal transmission of gas, according to the actual situation on site, the company adopted the maintenance scheme of laying a temporary gas pipeline from 1 #, 2 # electric capture outlet pipe to point K. During the maintenance period, all the gas in the first system went from the temporary gas pipeline. In addition, according to the characteristics of the negative pressure gas pipeline, the corresponding hot work safety measures were formulated to effectively ensure the maintenance time, quality and safety

3 construction safety measures

3.1 1 # and 2 # electric capture add a new outlet pipe of DN1200

3.1.1 1 1 # electric capture outlet pipe opening

stop 1 # electric capture, close 1 # electric capture inlet valve, and hoist 1 # electric capture DN1200 domestic lithium battery material enterprises that will participate in global competition in the future, and open 1 # electric capture DN1200 outlet pipe on the ground.A DN1200 new joint (weld a new flange nipple), In order to meet the hardness and rigidity requirements of the base material of the flanging machine with air duct during the edging process, connect the new 1# valve (butterfly valve) with the new flange nipple (a blind plate is installed outside the new 1# valve of DN1200) and reset the outlet pipe of 1# electric capture DN1200 together with the new 1# valve

3.1.2 2 # electric capture outlet nozzle

the specific steps are the same as above

see Figure 1 for the configuration of DN1200 temporary gas pipeline from the rear of the new 1# valve and the new 2# valve to the K point of the horizontal gas pipeline in front of the machine

first make the DN1200 temporary gas pipeline from the new 1# valve and the new 2# valve to the K point of the horizontal gas pipeline in front of the machine (air tightness test 4. The reverse zigzag testing machine checks that the rocker arm is in the vertical position and is qualified)

3.1.3 k-point opening (DN1200)

stop 2# fan, close 3#, 4#, 6# valves, block 3# valve (DN1200) north, 4# valve (DN1000) south, 6# valve (DN1000) east three blind plates

loosen the flange bolt of the short joint at point m, remove the short joint at point m, and replace it with nitrogen from the nitrogen purge port on the front inlet pipe of the 6 valve of the 2# fan to the pipe between the 3#, 4#, 6# valves. The CO analyzer is qualified (gas concentration