kimawi
Chemical
- Jul 27, 2008
- 21
Hi Folks,
We are installing a Roots blower to deliver gas to a burner, the blower has a negative suction pressure of about -20 kPag. We want to install a PSV on the blower's discharge side but have no nearby flare system. Our options are to either relief the gas to the atmosphere (least preferred) or pipe PSV to the blower's suction. With this second option of recycling the gas back to the blower a few issues are not clear to me:
1) The back pressure of the PSV will initially be negative and then builds up and keeps increasing, how would that affect the PSV set pressure? would a Balanced Bellows style needed in this case?
2) The gas temperature will no doubt keep increasing due to compression when the PSV opens, can we simply protect the blower with a temp switch (on the blower's discharge) that trips the blower at a certain point?
I am assuming here that accidental shutting of valves downstream the blower will trigger the opening of the PSV.
Any help would be appreciated.
We are installing a Roots blower to deliver gas to a burner, the blower has a negative suction pressure of about -20 kPag. We want to install a PSV on the blower's discharge side but have no nearby flare system. Our options are to either relief the gas to the atmosphere (least preferred) or pipe PSV to the blower's suction. With this second option of recycling the gas back to the blower a few issues are not clear to me:
1) The back pressure of the PSV will initially be negative and then builds up and keeps increasing, how would that affect the PSV set pressure? would a Balanced Bellows style needed in this case?
2) The gas temperature will no doubt keep increasing due to compression when the PSV opens, can we simply protect the blower with a temp switch (on the blower's discharge) that trips the blower at a certain point?
I am assuming here that accidental shutting of valves downstream the blower will trigger the opening of the PSV.
Any help would be appreciated.
