To provide a new arrangement for synchronizing gradient generator by equalizing re-compression volume to re-compression volume of a high pressure pump.
During the initial portion of the pumping stroke of a first piston in which fluid is being compressed due to its finite bulk modulus of elasticity its check valve remains closed, a second piston provides all the flow required at a fixed rotational speed. Then, once the pressure inside the first piston's cylinder has reached that of the discharge and its discharge check valve opens, the control system switches to a constant-pressure control mode, thereby maintaining the flow rate at a fixed value. Constant-pressure control is again switched off when the second piston's discharge check valve closes, and pump control returns to fixed rotational speed. Determining the angular displacement at which to effect these control-mode switches is carried out by monitoring the discharge pressure and storing the values of the angular displacement at which the first temporal derivative of pressure changes rapidly.
BLAKLEY SCOTT L
WALTERS HENRY L
| JPH10159750A | 1998-06-16 | |||
| JPH03168369A | 1991-07-22 | |||
| JPH11287180A | 1999-10-19 | |||
| JPS4979595A | 1974-08-01 | |||
| JPS54149904A | 1979-11-24 |