【Haichuan’s Best Practices】Mechanical cleaning of oily wastewater tanks to reduce risks in confined space operations
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According to Sinopec News Network, recently the Olefins Department of Shanghai Petrochemical used mechanical cleaning for the first time to carry out online cleaning of the No. 3 olefins oily wastewater tank. This approach not only reduced the impact on the normal operation of the facility but also enabled the separation of waste materials, resulting in an improved working environment at the site compared to before. Due to the long-term operation of the facility, sludge tends to accumulate at the bottom of the oily wastewater tank, reducing its effective volume and thereby affecting the proper operation of the facility. With the mechanical cleaning method, cleaning can be carried out online simply by installing cleaning equipment near the oily wastewater tank; this does not affect the normal operation of the equipment, and there are no longer any restrictions on the cleaning cycle. During cleaning, the sludge and wastewater at the bottom of the tank are pumped to the recycling equipment using an underwater slurry pump. Mechanical cleaning is used, and during the 2–3 week cleaning process, there is no need to remove the lid of the oily wastewater tank. While processing oily sludge, the cleaning equipment can also simultaneously separate the three types of waste: it treats exhaust gases to remove VOCs, discharges treated wastewater into the sewage system, and transports the solid waste to designated locations after dehydration. By using mechanical cleaning, operators no longer come into direct contact with sludge, resulting in higher safety compared to manual cleaning and better cleaning results. To ensure the smooth progress of the initial mechanical cleaning, the management of Unit 3 for olefins supervised the operations on site, working together with the team supervisors and the construction party’s supervisors to guarantee safety throughout the process. (Huang Qiang)
Mechanical cleaning of oil-containing wastewater tanks is theoretically simple and technically feasible, but in practice it is not. There are many types of sewage tanks in chemical plants, with various factors such as structure, size, medium, and frequency of use. If mechanical cleaning techniques can be applied in these situations, it will not only help reduce the costs associated with manual cleaning but also prevent potential safety hazards, which is indeed a great advantage.
It’s fine if it’s sealed, but otherwise the exhaust gases will leak out; I’m really worried that something might go wrong! :L
Many things are also refined through use; versatility and multi-applicability are definitely advantages. If too many changes are made, it becomes useless
Yes, these issues need to be considered before implementation, and effective measures should be put in place
On June 13, 2020, workers at Meixinda Dyeing and Printing Company in Wuxing District, Huzhou City, suffered hydrogen sulfide poisoning while cleaning a reaction tank, resulting in 4 deaths and 5 injuries.
Every year, there are many accidents that occur while cleaning these tanks in confined spaces. Therefore, there are some useful methods that can be adopted, but they shouldn’t be copied verbatim; it’s necessary to adapt them to the actual situation. In any case, it’s important to first comply with all the regulations and requirements related to working in confined spaces
The Safety Committee Office of the Inner Mongolia Autonomous Region issued an urgent notice titled \"On Thoroughly Learning from the ‘7·4’ Serious Poisoning and Asphyxiation Incident at Tongliao Xinhao Agriculture and Animal Husbandry Co., Ltd. and Strengthening the Management of Safety Risks in Work in Confined Spaces.\" The notice reported that at around 10:33 on July 4, maintenance workers employed by Tongliao Xinhao Agriculture and Animal Husbandry Co., Ltd. suffered a serious poisoning and asphyxiation incident during their maintenance tasks, resulting in 3 deaths and 5 injuries. The Safety Committee Office of the Inner Mongolia Autonomous Region requires that the accident be investigated and dealt with strictly in accordance with the law, that its causes be determined scientifically, that its nature be identified, that lessons learned from the accident be summarized, that targeted improvement measures be proposed, and that those measures be enforced. Relevant responsible units and individuals must be dealt with strictly in accordance with laws and regulations; joint disciplinary actions should be intensified, so as to truly use the lessons learned from these accidents to improve safety practices in confined space operations within enterprises. At the same time, the relevant member units of the safety committees in various leagues, cities, and autonomous regions should also draw serious lessons from these accidents, strengthen efforts to ensure safe production in confined space operations, effectively prevent and firmly curb severe production safety accidents, and maintain stability in the region’s overall production safety situation. It is reported that we are currently in the hot summer season, during which toxic and harmful gases are more likely to evaporate. Increased demand for water and electricity leads to more inspections and repairs in confined spaces, and heat exhaustion among workers results in various accidents. The Office of the Autonomous Region’s Safety Committee requires that all regions and relevant departments immediately organize inspections and supervision of enterprises in their respective sectors that are involved in work in confined spaces, as well as key units and areas such as those involved in municipal engineering construction, gas supply, heating, sewage management, sanitation, and livestock farming. Special attention should be paid to assessing the safety conditions of sewage tanks that have been abandoned or out of use for long periods, as well as the implementation of safety measures. Any identified risks must be recorded, corrected within a set time frame, and follow-up actions taken to ensure that safety risk control measures are properly implemented and potential hazards are prevented. It is necessary to resolutely overcome complacency and a sense of luck, strictly fulfill regulatory responsibilities, and, in line with the three-year action plan for safety special rectifications, treat work in confined spaces as an important aspect of such rectifications as well as a mandatory item in safety enforcement inspections. By drawing lessons from similar cases, a comprehensive special rectification effort should be carried out to ensure safety in work in confined spaces, in order to firmly curb the frequent occurrence of accidents in these environments. (Reporter: Zhang Qiaozhen; Photographer: Zhang Yun) Source: Inner Mongolia News Network, Hohhot
That is, these high-risk tasks should be more mechanized and automated