Mixing apparatus for microflow gradient pumping

US5664938A · kind A · utility

Inventor

• Frank Yang · Danville, US

Key dates

• Filing date: Feb 23, 1995
• Grant date: Sep 9, 1997
• Expiry date: Feb 23, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/86163
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An improved mixing unit and check valve for a fluid pumping system wherein gradient proportioning is performed at high pressure are described. The mixing unit has lining means disposed on the inner surface of the chamber for preventing frictional contact between the steel of the chamber and the surface of the rotor. The lining means is formed of a polymeric material selected for frictional compatibility with the rotor, and avoids formation of undesirable particulates by friction with the rotor surface. The check valve has a poppet comprising a midsection dimensioned to provide forward and rearward surfaces against which fluid flow will exert force, a first arm extending transversely from the midsection first side toward the valve inlet, a second arm extending transversely from the midsection second side toward the valve outlet, and first and second resilient seals respectively annularly disposed about the first and second arms. The resilient seals are formed of a resiliently compressible material, and have an uncompressed thickness which is somewhat greater than the first arm length.