According to GB 18483-200 1 Oil Smoke Emission Standard, 2mg/m3 is the only acceptance standard. Catering units that have passed the acceptance of this standard can think that their emissions are legal, but they cannot confirm that their emissions will not disturb the people.
Even restaurants and other catering industries that use high-altitude smoke exhaust may cause serious complaints because of the air pollution in the public space on the roof caused by smoke exhaust, especially the complaints caused by direct smoke exhaust at the bottom of the building. Therefore, soot emission is a big problem. It is necessary to adopt different acceptance criteria for different oil fume emission methods. Too many acceptance criteria may bring operational difficulties and arbitrariness. It is feasible to implement two acceptance criteria for low-altitude direct discharge and high-altitude emission respectively.
At present, there are few problems encountered by environmental protection departments in handling the monitoring and acceptance of high-altitude emission of lampblack according to the acceptance standards implemented by the national standard. Therefore, it seems that there is nothing wrong with continuing to adopt this standard before the introduction of a new and stricter national standard. However, the current national standard does not have much practical significance for the acceptance of low-altitude emission of soot.
At present, the complaints of urban residents about lampblack basically happen after being troubled by lampblack for a long time. In addition to being unsightly, the fumes emitted from high altitude generally do not directly disturb a wide range of neighbors, and the probability of complaints from angry neighbors is far less than that from low altitude. Even if the high-altitude emissions are not up to standard, there are usually few complaints, but even if they are completely up to standard, there are few cases where they are not complained. It can be seen that the acceptance standard of low-altitude emissions is definitely much higher than the current single standard.
The ideal acceptance standard for low-altitude direct exhaust is, of course, "smoke-free, odorless and discharged at room temperature at all times"; "Smokeless emission" is a sensory standard that varies from person to person, and it is obviously unreasonable as an environmental protection acceptance standard. The quantitative data standard should be obtained as follows: Select the most typical restaurants with different scales of Sichuan cuisine and Hunan cuisine, and require long-term monitoring of the peak smoke concentration of smokeless emission purification effect under the critical state of saturated passenger flow, and take this peak as the standard quantitative value of smokeless emission. In the actual monitoring process or on-site handling of complaints, it can be directly judged by the naked eye whether it exceeds the standard. Of course, legal instrument measurement data is still needed as the basis for administrative punishment or other related procedures.