Accident case analysis: one question per Monday (10). +3 wealth for participation, plus an additional 1–10 wealth for correct answers

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This post was last edited by wang*nhua77020 on 2016-7-8 at 15:25. At 16:10 on a certain day, the maintenance team at a factory began connecting the oil transfer pipelines to the sludge tank. At 16:20, Fitter A inserted the oil pipeline with a bottom valve into the sludge tank; at that time, the oil level in the tank was 500 cm high, with 30 cm of sludge on top of it. When attempting to connect the flange at a height of 100 cm above the oil surface, it was not possible to make a proper connection due to the misalignment of the flanges, so Team Leader B decided to use welding instead. At 17:10, welder C arrived at the site with the welding machine. Since the work was to be carried out near the oily waste tank, welder C prepared everything on site before going to the workshop to obtain a fire permit. At 17:20, Blacksmith A, seeing that Welder C had not returned yet and as quitting time was approaching, began welding using an electric welder. After about 3 minutes of welding, an oil and gas explosion occurred; the explosion lifted the lid of the oil tank, causing the oil tank to catch fire, and Blacksmith A fell into the oil tank and died. Based on the above scenario, answer the questions (multiple-choice). 1. The nature of this accident is () A. Natural disaster B. Criminal case C. Faulty accident D. Non-faulty accident E. Accidental accident 2. The direct cause of the explosion in this accident was () A. Poor ventilation B. Narrow working area C. Inappropriate ambient temperature D. Illegal use of fire D. Improper handling of flammable and hazardous materials 3. The factors that led to the oil and gas explosion in this accident included () A. Air B. Gases emitted from contaminated oil C. Ambient temperature D. Sparks generated during welding E. Contaminated oil 4. The main hazards present in the working environment where blacksmith A worked were () A. Electromagnetic radiation B. Electric shock C. Fire caused by oil and gas D. Explosion caused by oil and gas E. Mechanical injuries 5. Based on the above circumstances, the indirect causes of the explosion included () A. Inadequate organization of work B. Insufficient safety training C. Lack of proper supervision at the site where fire was used D. Absence of a system for issuing permits for using fire E. Weak safety awareness. Answers and explanations: 1. The nature of this accident is (C). A. Natural disaster B. Criminal case C. Faulty accident D. Non-faulty accident E. Accidental accident. This was clearly an accident resulting from illegal use of fire, hence it is a faulty accident, and also a case of negligence ； 　2 The direct cause of this accident was (　D) 　　A. Poor ventilation 　　B. Narrow working space 　　C. Inappropriate ambient temperature 　　D. Illegal use of fire 　　E. Incorrect handling of flammable and hazardous materials. The main reason for this accident was that the workers violated safety procedures ； 　3. The factors that caused the oil and gas explosion in this incident are (　ABD　). A. Air B. Gases emitted from volatile contaminated oil C. Ambient temperature D. Sparks generated during welding E. Contaminated oil. The three elements required for an explosion are oxygen (air), a combustible material (oil and gas), and a source of ignition (welding sparks). 4. The main hazards present in the working environment of fitter A are (　BCD　). A. Electromagnetic radiation B. Electric shock C. Fire caused by oil and gas D. Oil and gas explosion E. Mechanical injuries. Welding operations carry a risk of electric shock ； Oil and gas also pose risks of fire and explosion. 5 Based on the above situations, the indirect causes of explosions include (ABCE). A. Inadequate organization of operations; B. Insufficient safety training; C. Inadequate supervision at the site where welding is carried out; D. Absence of a system for issuing permits for welding; E. Weak safety awareness. After preparing everything on site, Bing went to the workshop to obtain a welding permit, which shows that the company does have a system in place for such activities ；