I have an application on which I would like a few comments/ideas etc. I am not looking for specific programming here, just a concept analysis sort of thing. There are two schools of thought on this project. I will not say which side of the fence each of us is on so as not to prejudice your comments (like it really would LOL).
I have a material handling system that feeds a Bepex grinding mill. Here is a link to the mill equipment.
http://www.bepex.com/pulvocron.htm
Material is fed to the mill from an 80ft. silo which supplies a Smoot Rotary Feeder at the bottom of the silo. Here is a link for the feeder.
http://www.premierpneumatics.com/alockHD.htm
Finally we are moving the material with a Sutorbilt Model 4MP Blower which will develop about 15 PSIG using a TECO model MA7200 AC vector drive.
So what we have is a blower which goes to a transfer hopper with the rotary feeder at the bottom. From there the material blows up to the top of our silo where it is stored until the mill demands material.
We want the transmitter at the outlet of the blower to produce 7 PSIG (setpoint). We can do this by varying the speed of the motor drive. More material dumped into the lines means more back pressure. When the lines are empty the blower is about 2.14 PSIG. At 25hz on the drive we have 6.8 PSIG. There are no sensors of any type on the hopper. There are no level switches, bindicators or anything to determine that material is actually present in the hopper. Here is what one person had to say:
“You need the PSI on the blower to tell the rotary feeder when it is empty. Meaning when psi drop from 6 to 1-2 psi the feeder should sound a alarm. Let the operator know its empty or after 5 min the system automatic shuts down. For as plugging, the moment it see 8 psi the feeder stops feeding material. Let me know if this works.”
The other school of thought is that some type of level sensor is essential to this system. The reason being is that when the hopper goes empty, the controls will naturally call for more and more feed which is not there. Within a short period of time the feeder will spin up to high speed and when material is fed into the hopper, it will plug the lines.
Plugging of these lines is critical. It just can’t happen. It is too damned expensive to clean out the lines and get the system running again.
As far as feedback on the motor, the drive has several outputs that could confirm a fault or that the motor has been asked to start, but not that it is actually running.
OK, I need some spitballing here. You can probably guess where I fall on this, but I need some really good suggestions. BTW, this all goes to a Siemens 315 processor, S7 with a MP270B Siemens HMI.
Thanks in advance,
Robert
I have a material handling system that feeds a Bepex grinding mill. Here is a link to the mill equipment.
http://www.bepex.com/pulvocron.htm
Material is fed to the mill from an 80ft. silo which supplies a Smoot Rotary Feeder at the bottom of the silo. Here is a link for the feeder.
http://www.premierpneumatics.com/alockHD.htm
Finally we are moving the material with a Sutorbilt Model 4MP Blower which will develop about 15 PSIG using a TECO model MA7200 AC vector drive.
So what we have is a blower which goes to a transfer hopper with the rotary feeder at the bottom. From there the material blows up to the top of our silo where it is stored until the mill demands material.
We want the transmitter at the outlet of the blower to produce 7 PSIG (setpoint). We can do this by varying the speed of the motor drive. More material dumped into the lines means more back pressure. When the lines are empty the blower is about 2.14 PSIG. At 25hz on the drive we have 6.8 PSIG. There are no sensors of any type on the hopper. There are no level switches, bindicators or anything to determine that material is actually present in the hopper. Here is what one person had to say:
“You need the PSI on the blower to tell the rotary feeder when it is empty. Meaning when psi drop from 6 to 1-2 psi the feeder should sound a alarm. Let the operator know its empty or after 5 min the system automatic shuts down. For as plugging, the moment it see 8 psi the feeder stops feeding material. Let me know if this works.”
The other school of thought is that some type of level sensor is essential to this system. The reason being is that when the hopper goes empty, the controls will naturally call for more and more feed which is not there. Within a short period of time the feeder will spin up to high speed and when material is fed into the hopper, it will plug the lines.
Plugging of these lines is critical. It just can’t happen. It is too damned expensive to clean out the lines and get the system running again.
As far as feedback on the motor, the drive has several outputs that could confirm a fault or that the motor has been asked to start, but not that it is actually running.
OK, I need some spitballing here. You can probably guess where I fall on this, but I need some really good suggestions. BTW, this all goes to a Siemens 315 processor, S7 with a MP270B Siemens HMI.
Thanks in advance,
Robert