Announcement of the Investigation Report on the "1.15" Major Production Safety Responsibility Accident in Panjin, Liaoning Province
At around 13:25 on January 15, 2023, Panjin Haoye Chemical Co., Ltd. experienced an explosion and fire accident during the pressure sealing operation of the inlet pipeline of the water washing tank in the alkylation unit, resulting in 13 deaths and 35 injuries, and a direct economic loss of approximately 87.99 million yuan.
It is understood that after the accident, on-site investigation, expert technical analysis, and public security investigation have ruled out the possibility of accidents caused by factors such as human destruction and natural disasters. The accident investigation team has determined that the "1.15" explosion and fire accident of Panjin Haoye Chemical Co., Ltd. is a major production safety responsibility accident.
1、 Accident process
On January 11, 2023, Haoye Chemical discovered a leak at the edge of the elbow fixture of the accident pipeline. Haoye Chemical's Equipment Department organized maintenance and blocked the leak three times on January 11, 12, and 14, all of which were unsuccessful.
Leakage at the edge of the bend clamp of the accident pipeline
At around 13:00 on January 15th, Haoye Chemical and maintenance units once again began organizing and implementing pressurized sealing operations. On site, two cranes are used to lift one basket each, and two leak sealing operators are arranged in each basket to be lifted by the crane to the leakage point. The crane is commanded by a walkie talkie.
At 13:24:10, while installing and tightening one set of bolts on each side of the new fixture, the pipeline weld at the horizontal end of the original fixture suddenly broke, and a large amount of medium sprayed out from the fracture. The on-site monitoring personnel shall immediately evacuate outward and arrange for the operators inside the alkylation unit to stop urgently.
At 13:25:53 seconds, an explosion and fire occurred in the alkylation unit area.
2、 Direct cause of accident
The accident pipeline leaked and broke during the pressure sealing operation. A large amount of reactive effluent was sprayed out from the water washing tank, mixed with air to form an explosive vapor cloud. When encountering an ignition source, it exploded and caught fire, causing significant casualties in on-site operations, monitoring, and explosion shock waves within the scope.
The investigation found that the four walkie talkies used for homework command are non explosion-proof walkie talkies, with a minimum operating voltage of 4.5V and an estimated current passing through at a lower value of 100mA. If the connection time lasts for 0.1s, the spark energy is E=UIt=45mJ. In addition, there are two working cranes on site, and their exhaust pipes can have a high temperature hot surface temperature of up to 800-900 ℃. In the leaked medium, the minimum ignition energy of n-butane is 0.25mJ and the ignition temperature is 405 ℃; The minimum ignition energy of isobutane is 0.52mJ, and the ignition temperature is 460 ℃.
After comprehensive analysis by the expert group, it has been determined that the ignition sources causing this explosion are: firstly, the energy generated during intercom communication, and secondly, the high-temperature hot surface of the exhaust pipe of the crane at the work site.
The indirect causes of the accident also include: the construction unit's unauthorized decision to replace the accident pipeline with 20 steel instead of 316 stainless steel without design changes; Failure to develop construction plans and emergency measures, conduct on-site surveys, and handle operational approvals for pressurized sealing operations in accordance with regulatory requirements; The daily management of special equipment in enterprises is seriously lacking.
3、 Suggestions for handling responsible personnel and responsible units
Fines and written inspections will be imposed on 12 responsible units, including accident related enterprises, Panjin Emergency Management Bureau, Panjin Market Supervision Bureau, Panshan County Committee, County Government, Panjin Municipal Committee, and Municipal Government.
Two responsible persons for the accident were exempted from liability due to their deaths, and 14 responsible persons were taken compulsory measures by the public security organs; 48 public officials related to the accident have been held accountable, and the relevant responsibility facts have been transferred to the discipline inspection and supervision commission for handling in accordance with regulations and laws; 11 personnel responsible for the accident have received administrative penalties.
It is understood that after the accident, Panjin City immediately organized a team of experts to conduct comprehensive risk identification and hidden danger investigation on the accident enterprise, comprehensively rectify the safety management issues of the enterprise, and update and renovate relevant equipment and facilities. The Provincial Emergency Department has organized a special investigation and rectification work for equipment defects in chemical enterprises throughout the province, comprehensively rectifying the operation problems of equipment defects, and strictly preventing similar accidents from occurring.
