Why do you have to ensure that the working face is well ventilated when driving through the roadway?

When digging in the roadway, the purpose of ventilation on the working surface is two. One is to discharge the gun smoke and a large amount of dust generated by the blasting in a short time. In order to facilitate the loading of rock work; the second is to supply fresh air to the working face, discharge dust and dirty air generated by rock drilling and rock loading, reduce the working surface temperature and create a better working environment. Since the tunneling is a single-head construction, it is difficult to form a through-flow. Therefore, the local fan is generally used for ventilation. The ventilation time after blasting is generally not less than 40 minutes, and the personnel can enter the working surface for rock loading.
The tunnel ventilation mode can be divided into three types: press-in type, draw-out type and hybrid type, among which the mixed ventilation effect is the best.

Animals Puzzle Mat

Animals Puzzle Mat is a educational puzzle mat, a learning tool, and a cushioned play area all rolled into one. The different animals shapes pop out to teach basic animal and color recognition; and the cushioned pieces provide a soft play area, making it perfect for playrooms, nurseries, classrooms, gyms, and more. Made of easy-to-clean EVA foam, the squares stack nicely together for easy transport.

Interchangeable pieces allow kids to develop gross motor skills, hand-eye coordination, and visual sensory growth, large, cushioned, and colorful puzzle pieces are very safe, not only for your children but they also protect your floors against damage.

Animals Puzzle Mat,Eva Puzzle Animal Mat,Baby Animal Puzzle Mat,Puzzle Mat For Kids,Multi Coloured Puzzle Mat,Puzzle Animal Play Mat

Huizhou City Melors Plastic Products Co., Limited , https://www.grandfoam.com