摘要 |
<p>A ratio mixing valve for mixing first and second fluids in a constant volumetric ratio regardless of variations of supply pressures of the two fluids. The valve has an inlet passage for the first fluid that passes through a spool valve chamber, and an inlet passage for the second fluid that also passes through the spool valve chamber. Vent passages connect the two fluid passages to the ends of the spool valve chamber. The spool valve has a pair of annular grooves aligned with the two inlet passages. One groove partially blocks one of the inlet passages to form a variable orifice that responds to pressure changes in the incoming fluids by moving the spool valve to a position which adjusts the volumetric flow through the two passages to maintain a constant ratio between the fluids in the mixture.</p> |