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Old June 25th, 2007, 06:22 PM   #1
Greg Dake
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Corn Syrup Flow...

Greetings everyone,

We have an upcoming application where we need to measure volumetric flow of corn syrup. This is our first time we've had to pump corn syrup. We will be pumping it out of a storage silo and delivering it to various batching areas.

For those with experience, which flow meter technologies have you had the best luck with? My collegues are concentrating on coriolis flow meter technologies. The coriolis meters are very expensive, but possible if that is the route we need to go. Do any of the other flow meter technologies work well with corn syrup?

Also, the syrup is going to be pumped with a positive displacement pump. I could put an encoder on the pump to know how many revolutions the pump has turned, therefore being able to know the volume delivered. This has a few bad points, if there is any tunneling with the syrup we wouldn't always have a guaranteed volume per pump revolution. Has anyone done this with a positive displacement pump to get an accurate volume pumped? This method just seems to have too many variables.

TIA,

Greg
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Old June 25th, 2007, 07:45 PM   #2
Gunner
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Greg,

IMHO.

Load Cells would be by far the best route to go for this sort of project.

regards

Gunner
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Old June 25th, 2007, 08:02 PM   #3
Greg Dake
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We talked about it...

Gunner,

You are correct, however our silos are permanent installations which are several stories tall and not really load cell material...Alternatively we could pump into a second smaller tank to batch the corn syrup which could be on load cells. We're trying to avoid the second tank with load cells though...

GReg
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Old June 25th, 2007, 09:32 PM   #4
curlyandshemp
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Quote:
Originally Posted by Greg Dake
Gunner,

You are correct, however our silos are permanent installations which are several stories tall and not really load cell material...Alternatively we could pump into a second smaller tank to batch the corn syrup which could be on load cells. We're trying to avoid the second tank with load cells though...

GReg
I have done batching applications using Hydex and Invert. Both very similiar to corn syrup. First make sure the batching lines have heat tracing to keep the syrup flowing.

Less expensive mag flowmeters will not work, as the syrup does not have enough conductivity to provide pulses consistently. Only meters I have seen working successfuly are the old 'dial and count' style that uses an inline impeller to count pulses of the syrup flowing, or
Coriolis.

A positive pump must be used, and make sure there is a pressure relief loop around the pump. A spring adjustable actuated sanitary pressure relief valve will work well.

Also, your application will require setpoints in Lbs as the Coriolis meter provides a mass signal, usually 0.1, 1 or 10 pounds per pulse
An E & H Promass 83F50 should work well.

Ian
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Last edited by curlyandshemp; June 25th, 2007 at 09:46 PM.
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Old June 25th, 2007, 09:42 PM   #5
curlyandshemp
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Quote:
Originally Posted by Greg Dake
Gunner,

You are correct, however our silos are permanent installations which are several stories tall and not really load cell material...Alternatively we could pump into a second smaller tank to batch the corn syrup which could be on load cells. We're trying to avoid the second tank with load cells though...

GReg
The cost of a second tank, load cells , indicator, second pump will far exceed the cost of a massflow meter

Ian
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Old June 26th, 2007, 01:25 AM   #6
DaveW
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I agree with Curly. We do a lot of batching applications and uses a positive displacement meter like the one below. With syrups, if the flow is slow enough, you can use a dc discrete input vs. a high speed counter module. If you are feeding alot of tanks, you can use one meter and a valve for each tank. You will have to run tests and setup preacts for each tanks.

http://www.andinst.com/PDFs/5031.pdf
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Old June 26th, 2007, 05:53 AM   #7
bikerdude
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Greg,
We use a pulse type meter similar to the one DaveW has in the link above, just a diffeent model: http://www.andinst.com/PDFs/5034.pdf (PDF). We also use a Durant totalizer / flow interface. With the Durant/Eaton Rate meter the operator has to type in the desired total for a batch & hit the start button. This closes a relay within the meter giving the PLC a discrete input. When the batch has counted down to zero, the relay will open, removing the PLC input. The PLC will start the PD pump if all conditions are met(safetys). We move about 1/2 million pounds a day like this with minimum problems.http://www.eaton.com/ecm/idcplg?IdcS...ILE&dID=119877 (PDF) page#30
Hope this helps.
BD
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Old June 26th, 2007, 09:48 AM   #8
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Quote:
Originally Posted by Greg Dake
Gunner,

You are correct, however our silos are permanent installations which are several stories tall and not really load cell material...Alternatively we could pump into a second smaller tank to batch the corn syrup which could be on load cells. We're trying to avoid the second tank with load cells though...

GReg

Greg, I just posted this link on antoher thread, but check out this load cell, it might work for you as well depending on your silo arrangement - its a load cell that bolts onto the legs of a vessel rather than being plaaced under the legs to determine the weight of the vessel contents based on support member strain instead of putting the load cell under the vessel.
http://www.kistlermorse.com/p_lcell.asp

How about a positive displacement flow meter such as http://www.koboldusa.com/flow/s4-ovz.htm? This one is kind of small, you didn't say what the range was.
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Last edited by TConnolly; June 26th, 2007 at 09:52 AM.
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Old June 26th, 2007, 10:03 AM   #9
Greg Dake
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Thanks for the responses so far....


Alaric, those load cells are interesting. I can see other applications where they can be used. On the particular silo we are going to be storing corn syrup, there aren't any horizontal support members. These silos are essentially sitting on the floor, they are very large....20,000gal in size. The silo is 25' tall and roughly 13' in diameter. The silo is in place, so the load cell wouldn't work unless we used a second day tank to batch up into first which is not preferrable. The flow rate is 0-40gpm for the corn syrup.

Greg

Last edited by Greg Dake; June 26th, 2007 at 10:21 AM.
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Old June 26th, 2007, 10:11 AM   #10
TConnolly
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Would it be possible to put some laminar flow vanes in the pump feed line to eliminate any tunneling? That would improve the accuracy of counting pump revolutions.
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Old June 26th, 2007, 10:18 AM   #11
curlyandshemp
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Quote:
Originally Posted by Alaric
Greg, I just posted this link on antoher thread, but check out this load cell, it might work for you as well depending on your silo arrangement - its a load cell that bolts onto the legs of a vessel rather than being plaaced under the legs to determine the weight of the vessel contents based on support member strain instead of putting the load cell under the vessel.
http://www.kistlermorse.com/p_lcell.asp

How about a positive displacement flow meter such as http://www.koboldusa.com/flow/s4-ovz.htm? This one is kind of small, you didn't say what the range was.
The problem with the KM cells, are the effects of temperature change. I see now they have a temperature compensation module.
When I used them last about 15 years ago, they were on syrup tanks in a beverage manufacturing plant. Any time someone hosed down the floor with hot water near the tanks, the weight readings would fluctuate. Also, whenever the nearby shipping doors were opened, and if the outside temperature was cold, the cold air would cause weight reading fluctuations.

Ian
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