Appts. for spraying hot molten bitumen into mixer - where bitumen is fed from heated tank via dosing pump to spraying nozzle

摘要

The bitumen is located in a thermally insulated tank provided with a heater. Near the base of tank is a bitumen outlet pipe provided with valves, a dosing pump, and a delivery pipe leading to a spraying nozzle with several outlet holes. Units are surrounded by a thermally insulated sheath which contains a heater so the bitumen is kept in a molten state. The dosing pump is pref. fitted with a pulse counter, which monitors the r.p.m. of the pump and its delivered vol.; and pump is pref. driven by a motor fitted with a brake so it stops immediately when it is switched off by a relay. A simple appts. delivering an accurate vol. of bitumen into a mixer which e.g. contains stone chips.