PlantOp
Chemical
- Dec 13, 2012
- 6
Hello, I'm an operator at a natural gas processing facility, and I would like to pick some of the brains of the engineers on these forums, if I could.
We are having issues with our propane reflux pumps vapor-locking when the overhead pressure on our de-propanizer tower gets too low. We are trying to reduce the pressure so that we run a higher Y-Grade feed to the tower, and thereby make more product (propane and butane). I would like to know if there is a way to reduce the pressure on the tower without vapor locking the reflux pumps. Are there any other pieces of equipment/piping we could add in order to alleviate this issue? Currently, we run about 165 psi of overhead pressure, with reflux temperature being at 70-80 degrees, and reflux flow at 245 gpm. The pumps are typically running at about 200 psi with these setpoints. If the pressure gets any lower than 165, one of the pumps will usually lock up, and we have to "blow down" the pump to get it going again. I have researched information on pump jackets and vapor lines going from the volute of the (centrifugal) pumps to the vapor space in the tower or reflux accumulator, but I would like some additional thoughts on the subject if possible. Thank you for any assistance that any of you could provide.
I will try to provide a P & ID later if that would help as well.
We are having issues with our propane reflux pumps vapor-locking when the overhead pressure on our de-propanizer tower gets too low. We are trying to reduce the pressure so that we run a higher Y-Grade feed to the tower, and thereby make more product (propane and butane). I would like to know if there is a way to reduce the pressure on the tower without vapor locking the reflux pumps. Are there any other pieces of equipment/piping we could add in order to alleviate this issue? Currently, we run about 165 psi of overhead pressure, with reflux temperature being at 70-80 degrees, and reflux flow at 245 gpm. The pumps are typically running at about 200 psi with these setpoints. If the pressure gets any lower than 165, one of the pumps will usually lock up, and we have to "blow down" the pump to get it going again. I have researched information on pump jackets and vapor lines going from the volute of the (centrifugal) pumps to the vapor space in the tower or reflux accumulator, but I would like some additional thoughts on the subject if possible. Thank you for any assistance that any of you could provide.
I will try to provide a P & ID later if that would help as well.
