Patent · US Expired

Fluid flow apparatus and method

US4275752A · kind A · utility

43Cited by
9References
8Claims
0Family size

Inventors

Key dates

Filing dateSep 24, 1979
Grant dateJun 30, 1981
Priority date
Expiry dateSep 24, 1999

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/2499
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

Apparatus for combining fluid flows in variable proportions is adapted for blending an active constituent gas and a diluent gas to calibrate gas analyzers used in monitoring pollution. Diluent gas passes from source 34 through a downstream differential pressure regulator 17 and a constant flow restrictor 12 to outlet 14 which communicates with control port 20 of regulator 17. Active gas passes from source 35 through differential pressure regulator 23, through three fixed parallel flow restrictors 22, 29 and 30 to combine with the diluent gas upstream of restrictor 12. Control port 26 of regulator 23 communicates with the input to restrictor 12. Switching of valves 31, 32 and 33 varies the rate of flow along conduit 16 and hence the proportions of gases combined upstream of restrictor 12. Regulator 23 maintains flow along 16 substantially constant for given valve settings, and regulator 17 maintains flow along outlet 14 substantially constant despite changes in flow rate in the conduit 16.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.