Patent · US Expired

Pressure management and vapor recovery system for filling stations

US6174351A · kind A · utility

21Cited by
17References
45Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 26, 1999
Grant dateJan 16, 2001
Priority date
Expiry dateMar 26, 2019

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N33/0047
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A vapor recovery and pressure management system for a vehicle refueling facility includes two rotary vane pumps and a hydrocarbon-stripping membrane between the pumps. One pump draws vapor from a storage tank as well as from refueling nozzles, while the other pump draws vapor from the membrane and discharges the vapor back into the tank. A controller controls both pumps to maintain a slight vacuum in the tank, thereby preventing leakage of hydrocarbons from the tank to the atmosphere. Clean air from the membrane is exhausted, preferably through a charcoal canister, and a hydrocarbon sensor monitors for the presence of undesirable hydrocarbons in the clean air exhaust. One or more liquid drop outs are provided for separating liquid from the hydrocarbon vapor and returning the liquid to the tank along with the vapor, preferably before the liquid is sent to the membrane, to thereby increase efficient fuel recovery and to protect the membrane from undesirable contact with liquid.

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