Tank accident 7: Explosion of a benzene tank at Harbin No. 4 Chemical Plant 《Downloaded from the Internet》

Thread Content

This post was last edited by Chuyun Waichao on 2018-8-31 at 12:11. Incident report of the benzene tank explosion at Harbin No. 4 Chemical Plant: At 21:30 on January 28, 1975, an explosion occurred in a benzene tank in the resin production section of Harbin No. 4 Chemical Plant; 6 people died, 8 were lightly injured, and the economic loss amounted to 49,000 yuan. On that day, Tank 2 in the resin section of the plant contained 540 kilograms of benzene, while Tank 3 contained approximately 800 kilograms of benzene. At 8:20, 6 operators were carrying out salt separation operations in Tank No. 3. During these operations, the operators opened the heating valve without authorization, and then left their posts without closing the valve, which resulted in 348 kilograms of the substance being spilled. At 21:30, an explosion occurred when this substance came into contact with an open flame, causing casualties and destroying 883 square meters of the workshop. Cause of the accident: Tank No. 3 was a static tank, but the operating procedures were incomplete. The operator opened the heating valve without authorization while separating salts, then left his post; he also forgot to close the heating steam valve, which resulted in pressure building up inside the tank and led to the release of benzene. The boiling point of benzene is 81 degrees. As the vent valve opened, the temperature inside the tank rose rapidly, causing the pressure to increase sharply. Once it reached a certain level, it overcame the seal at the tank’s opening, resulting in severe leakage of benzene. When this mixture reached its explosive limit and came into contact with an open flame, an explosion occurred. Regarding the factor of ignition by an open flame, it may be one of the following reasons: ①. Remnants of a flashlight in an on state were found at the scene. ②Nails were found under the victim’s fur-lined shoes at the site of the explosion. ③Before the explosion, a non-explosion-proof motor was in operation; the V-belts were connected with iron nails, and the terminal contacts could also generate weak sparks. Lessons learned and preventive measures: Strengthen three-level safety training for employees, carry out accident analysis activities to learn from such incidents, and improve employees’ safety knowledge and operational skills.