Testing of filter sands for air - raid shelter ventilation - determination of flow resistance 防空洞通風用濾砂試驗.氣流阻力測定
For economic reasons , we did much of the heavy work ourselves - transporting cement , sand , lime , and bricks from the foothills , tearing down the hut , mixing cement , filtering sand , and carrying bucketfuls of building material 為了節省開支,許多粗重的工作例如下山運水泥沙白灰磚,拆棚子拌水泥篩沙提灰桶等工作,我們都親自動手。
Manufactures : automatic softener consecutive water supply , inter - current water supply , meter and timer style , automatic filters sand filter , carbon filter , automatic desalination systems and automatic water purification system 水處理設備及系統有:全自動軟化水裝置連續供水及間斷供水流量型及時間型全自動過濾水裝置碳濾砂濾全自動除鹽水裝置全自動純水裝置。