Centralized unit pressurizing two-component polyurethane plastic resin supplied to valved injection lances

摘要

Transfer pumps (9.1, 9.2) for each component have associated feed pumps (4.1, 4.2). The latter extract each component separately from its transport container, feeding it under pressure to the transfer pumps. All pumps share a common drive, the transfer pumps connected to it through clutches (8.1, 8.2). Preferred features: The motor (M) drives gearing dividing power between pumps. Remotely operated dog clutches control the transfer pumps. Feed pumps extract excess volume in supplying the transfer pumps. A unit effects remote control. Clutches are actuated pneumatically via a 2/3-way solenoid valve. To switch on drive, pipeline back pressure is monitored by pressure switches; the 2/3 way valves are actuated by them, in accordance with pipeline injection pressure. At the end of pressurization, mixer flushing with hardener is initiated. Mixer shutoff valves isolate it from prepolymer. On reaching a sub-operational pressure, the prepolymer transfer pump is declutched and its feed pump goes into recycling mode. On reaching a lower pressure setting in the resin circuit, the unit goes into standby mode, with the motor switched on and the non return valves (1.1, 1.2) in safe state.