Hi Everyone,
Looking for ideas on a new project. Here are the details:
PLC - CompactLogix L33
VFD - PowerFlex 753
Ethernet/IP Control
We are unloading rail cars of Gasoline and Diesel and putting it into storage tanks. I have Pressure Transmitters on the pipe on the inlet to the pump and on the outlet from the pump. Those run into the PLC Analog Card.
The pump requires a minimum NPSHr of 6 ft at lower flows up to 8.5 ft at full flow. I have converted that to psi to give me a range of 1.9 to 2.95 psi.
I have done projects with this VFD but it was more simple control, based on the # of pump request. Never done one where I was looking at a dynamic input like pressure.
What I want to do is to use the PT's, PLC and VFD's to control the pump speed so I can pump as fast as I can without cavitating the pump.
As the rail car pumps down the NPSHa will drop so obviously I will need to slow down the pump. I was just looking for some ideas. I could just do some kind of range thing like:
Inlet Press >3psi run full speed
Inlet Press between 2 & 3 run and 3/4 speed
and so on
But I as thinking that there has to be a better more fluid solution for doing this. Maybe PID?
So if you have any experience in doing something like this I would love to hear how you handled it.
Thanks for the help!!
Looking for ideas on a new project. Here are the details:
PLC - CompactLogix L33
VFD - PowerFlex 753
Ethernet/IP Control
We are unloading rail cars of Gasoline and Diesel and putting it into storage tanks. I have Pressure Transmitters on the pipe on the inlet to the pump and on the outlet from the pump. Those run into the PLC Analog Card.
The pump requires a minimum NPSHr of 6 ft at lower flows up to 8.5 ft at full flow. I have converted that to psi to give me a range of 1.9 to 2.95 psi.
I have done projects with this VFD but it was more simple control, based on the # of pump request. Never done one where I was looking at a dynamic input like pressure.
What I want to do is to use the PT's, PLC and VFD's to control the pump speed so I can pump as fast as I can without cavitating the pump.
As the rail car pumps down the NPSHa will drop so obviously I will need to slow down the pump. I was just looking for some ideas. I could just do some kind of range thing like:
Inlet Press >3psi run full speed
Inlet Press between 2 & 3 run and 3/4 speed
and so on
But I as thinking that there has to be a better more fluid solution for doing this. Maybe PID?
So if you have any experience in doing something like this I would love to hear how you handled it.
Thanks for the help!!