Flow rate control device

A flow rate control device disposed in a flow path branching into a first flow path from an inflow port connected to a water supply pipe to a first outflow port connected to a backflow pipe, and a second flow path from the inflow port connected to the water supply pipe to a second outflow port connected to a mold pipe, and configured to control a flow rate of fluid supplied from the water supply pipe to the mold pipe, the flow rate control device comprising:

• a flow rate regulating valve configured to regulate an instantaneous flow rate of the fluid flowing in the flow path;
• a flow meter configured to measure the flow rate in the second flow path and produce continuous measurement results of the flow rate;
• and
• a controller configured to receive the continuous measurement results of the flow rate, and instantaneously control an opening degree of the flow rate regulating valve on each of the continuous measurement results of the flow rate produced by the flow meter, thereby controlling the instantaneous flow rate,
• wherein the flow rate regulating valve is a three-way flow dividing valve configured to:
• divide the fluid entering through the inflow port connected to the water supply pipe into the first flow path leading to the first outflow port connected to the backflow pipe, and the second flow path leading to the second outflow port connected to the mold pipe, and
• adjust a flow rate ratio flowing out of the first and second outflow ports,
• wherein the flow rate of the fluid entering through the inflow port remains constant even when the flow rate ratio flowing out of the first and second outflow ports changes,
• wherein the flow meter is located in the second flow path proximal to the second outflow port, and a multistage throttle orifice is located in the first flow path proximal to the first outflow port,
• wherein the multistage throttle orifice is formed by arranging a plurality of ring plates directly adjacent to one another in a thickness direction, each of the plurality of ring plates having a tapered throttle orifice,
• wherein the tapered throttle orifice comprises:
• a first aperture defining an inlet at a first end and tapering gradually from the first end toward a second end opposite the first end;
• a second aperture defining an outlet, the second aperture extending from the second end of the first aperture toward the outlet and having a cylindrical shape with a constant diameter, and
• wherein the constant diameter of the second aperture is equal to a diameter of the first aperture at the second end.