The thesis demonstrates the feasibility of natural ventilation to control concentration of noxious gas in the sewer tunnel.

并论证利用自然风稀释污水隧道内有害气体浓度的理论可行性。

Because these accident's occurrence mainly in the industry environment USES flammable explosive, the virulent noxious gas to create improper.

这些事故的发生主要因为工业环境中使用易燃易爆、有毒有害气体不当造成。

The utility model can not only prevent the dust and noxious gas in the air from entering the water box but also purify the water quality with an excellent effect.

本实用新型既可以防止空气中的灰尘、有害气体等进入水箱，又能很好地净化水质。

The positive effect of the utility model is to dissolute the waste rubber in comparatively low temperature without making noxious gas and with high recovery ratio and high automation.

本实用新型产生的有益效果是，将废旧橡胶在较低温度下进行分解，不产生有毒气体，回收利用率高，自动化程度高。

Enriching landscape structure and vertical artistic helps to increase green quantity, decrease heat island effect, deduce noise and noxious gas. The urban ecological environment has been improved.

丰富城区园林绿化的空间结构层次和城市立体景观艺术效果，有助于进一步增加城市绿量，减少热岛效应，洗尘、减少噪音和有害气体，营造和改善城区生态环境。