1.German OPTI belt roots blower. 2.Sweden SKF bearing roots blower. 3.Low noise roots blower ... , there is small flow rate changes along with pressure changes.2 tri-lobe linear-shaped impeller making inlet and outlet pulsation ... 8 Swedn SKF brearings9 Germany OPTI beltsUsage:sewage treatment,biogas firing system,printing pool stir, flour, aquaculture, pneumatic conveying, electric power and ...