After the Beef and Mutton Hall of Beijing’s Xinfadi Wholesale Market, the center of the epidemic in Beijing, was shut down on the 13rdof June and the vendors withdrew, it has become the high-risk area. Much meat left by the hastily escaped vendors rotted in the closed space, producing thick pollutants that were possibly viruses and methane.To avoid secondary pollution caused by virus leakage, the air conditioning and exhaust system of the Beef and Mutton Hall has been shut off. It is very difficult and dangerous for people to enter directly into the room for clear-up. How to eliminate the “Source of Pollution” in the least time and facilitate the entry of clean-up staff has become the top priority of the “Battle against Epidemic” in Beijing.
(The third from the left is Prof.Chen Chao)
Prof. Chen Chao from the Faculty of Urban Construction of BJUT, the national air treatment expert and a domestic research authority in the HVAC field, was appointed to design an emergency technical scheme for the pollution gas emission from the Beef and Mutton Hall of Xinfadi Wholesale Market. On the afternoon of June 20, she came to Xinfadi Wholesale Market to attend the on-site meeting about cleaning up the building where the Hall is located. After on-the-spot investigation and preliminary research, Prof. Chen Chao proposed to build a set of indoor air filtration and purification device outside the building connected with the roof ventilation system of the building. There are three problems needed to be solved within this system: first, avoid the “leakage” of polluting gas during the cleaning process; second, filter out the harmful gas that may cause secondary pollution; third, continue to purify air until the hall is cleaned up. There are three critical steps within the operation of the system: the first step is filtration, in which the filter for particles below PM 0.5 is used, and the toxic and harmful gas is preliminarily filtered through the non-woven fabric and filter paper; the second step is adsorption where the putrid gas is adsorbed by activated carbon; the third step is spraying where the air is disinfected by forming a water curtain with an appropriate proportion of 84 disinfectant.
The process of implementation is like a race against the clock. Prof. Chen Chao immediately contacted China Railway Construction Group Equipment Installation co., Ltd. to implement the air purification scheme. At 11:30 p.m. on June 22, after 55 hours of hard work, the over-100-meters outdoor ventilation and purification system which is composed of more than 60 components, was put into operation.Only7 hours was left before the clean-up staff entered the site at 6:30 am on June 23.
“It's not an empty word that we can make it at the critical moment.” Prof. Chen Chao said that without the highest attention and prompt decision of the Beijing Municipal Party Committee and Municipal Government, it is impossible to achieve such efficient settlement without “battle-tested” talent reserves.It is impossible to come up with such a feasible plan in the least time; without the development of the manufacturing industry. Andit is also impossible to assemble workable equipment insucha short time. Without “battle-seasoned” construction team, it is impossible to carry out the plan in such a shorttime. This is the battlefield of the “anti-epidemic soldiers”, and also the embodiment of overall national strength.
