Patent ID: 7828083
Filing Date: 2010-11-09
Classification: E21B

Abstract:
1. A method of controlling operation of a rock drilling rig the method comprising: determining the rate of flow of the flushing medium of the rock drilling rig on the basis of the rate of flow of the flushing medium flowing in a flushing channel system of the rock drilling rig; comparing the rate of flow of the flushing medium to a rate of flow limit value set for the rate of flow of the flushing medium; and when the rate of flow of the flushing medium drops below said limit value, increasing pressure of the flushing medium, wherein the pressure of the flushing medium is increased by increasing a control value of a pressure control valve included in the flushing system to a value above a set value of the pressure of the flushing medium acting during a normal state of the drilling, and wherein when the rate of flow has returned to a corresponding set value, the pressure control valve is controlled to return the pressure of the flushing medium to the set value of the pressure of the flushing medium acting during the normal state of the drilling.