초록

A vapor recovery system includes a product handling circuit and a control circuit. The control circuit maintains a negative pressure in the product handling circuit in order to prevent undesirable fugitive vapor emissions.

대표청구항 ▼

1. A vapor recovery system for recovering volatile liquid vapor produced when loading a volatile liquid product into a storage tank from a supply tank, said vapor recovery system comprising: a product handling circuit including a supply tank, a storage tank and a reaction vessel holding a bed of ads

1. A vapor recovery system for recovering volatile liquid vapor produced when loading a volatile liquid product into a storage tank from a supply tank, said vapor recovery system comprising: a product handling circuit including a supply tank, a storage tank and a reaction vessel holding a bed of adsorbent; anda control circuit including a controller that maintains a negative pressure in said product handling circuit in order to prevent undesirable fugitive vapor emissions during a first mode of operation when said volatile liquid product is being loaded into said storage tank from said supply tank and said volatile liquid vapor being produced is captured by said bed of adsorbent. 2. The system of claim 1 wherein said controller maintains a negative pressure in said product handling circuit in order to prevent undesirable fugitive vapor emissions during a second mode of operation when said bed of adsorbent is regenerated and previously captured volatile liquid vapor is returned to said storage tank. 3. The system of claim 1 wherein said reaction vessel includes a lead line and said product handling circuit is a solitary product handling circuit under control of said controller. 4. The system of claim 3, wherein said product handling circuit further includes (a) a vent line extending from said reaction vessel to said supply tank, (b) a vapor line extending from said lead line to a ullage in said storage tank above a level of volatile liquid product held in said storage tank, (c) a return line extending from said lead line to a position immersed in said volatile liquid product held in said storage tank and (d) a volatile liquid product load line extending between said supply tank and said storage tank. 5. The system of claim 4, wherein said control circuit includes a first flow control valve in said vent line, a second flow control valve in said vapor line, a third flow control valve and a vacuum pump in said return line and a pressure sensor to sense pressure in said product handling circuit and provide feedback to said controller. 6. The system of claim 5, wherein said pressure sensor senses pressure in said vapor line between said second flow control valve and said storage tank. 7. The system of claim 6, wherein said control circuit further includes a vapor management unit connected between (a) said vent line between said first flow control valve and said supply tank and (b) said vapor line between said second flow control valve and said storage tank. 8. The system of claim 7, wherein said vapor management unit includes a Stage I return relief valve set at a first pressure P1, a first atmospheric relief valve set at a second pressure P2 and a second atmospheric relief valve set at a third pressure P3 where P3