A pulse generating system for a pulsed working fluid supply, wherein the system comprises:
- a pipe, comprising an inlet end and an outlet end through which pulsed working fluid is delivered;
- a source of pressurized working fluid, fluidly connected to the inlet end of the pipe;
- an angle-seat valve, fluidly connected to the pipe between the inlet end and the outlet end, the angle-seat valve comprising a piston movable between a first end-of-stroke position, in which the piston completely closes the pipe, and a second end-of-stroke position, in which the piston opens the pipe with a maximum opening of the angle-seat valve;
- a source of pressurized control fluid;
- a pressure regulator, fluidly connected to the source of pressurized control fluid and configured to regulate a pressure of the control fluid;
- a three-port, two-position control valve, a first port of the control valve is connected to the pressure regulator, a second port of the control valve is connected to the angle-seat valve and a third port of the control valve is connected to a control fluid outlet, the three-port, two-position control valve being configured to control displacement of the piston of the angle-seat valve to any position between the first end-of-stroke position and the second end-of-stroke position, including the first end-of-stroke position and the second end-of-stroke position, by means of the control fluid, the pressure of the control fluid being regulated by the pressure regulator;
- and
- a control device in communication with the pressure regulator and the three-port, two-position control valve, the control device being configured to control the pressure regulator as a function of desired pulse amplitudes and to control the three-port, two-position control valve as a function of desired pulse frequencies, so as to proportionally displace the piston of the angle-seat valve and generate pulses of pulsed working fluid.