| 主权项 |
1. A flushing system of a drilling unit, wherein the drilling unit comprises a drilling machine and a tool connectable to the drilling machine, the flushing system comprising:
a pump unit for feeding pressurized flushing fluid, wherein the pump unit includes a pump and a power device for driving the pump; at least one feed duct for feeding the pressurized flushing fluid from the pump to the drilling machine; at least one valve disposed in the feed duct for controlling flow of the flushing fluid conveyed to the drilling machine; at least one sensing device arranged to measure at least one property of the fed flushing fluid; at least one control unit for controlling the feed of the flushing fluid in response to a sensing data received from the at least one sensing device; and wherein the pump unit is a variable flow rate pump unit provided with adjusting means allowing flow rate of the flushing fluid to be varied, the control unit being configured to determine flow rate of the flushing fluid on the basis of the received sensing data, and the control unit being further configured to control the flow rate of the fed flushing fluid by adjusting the pressure supplied by the pump; and at least a first feed duct and a second feed duct, which are operationally parallel relative to each other; the first feed duct being provided with a first valve and a first throttle; and the second feed duct is being provided with a second valve and a second throttle, the first throttle and the second throttle each having orifices, which differ in size, the first valve and the second valve being independently controllable, wherein the control unit is configured to control opening and closing of the first valve and the second valve according to the operation of the drilling unit. |
