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Need Suggestion for this Application
Batching system with different liquids and tanks with the same Flowmeter, need idea.

Hi there,

So here what my boss want me to do.

I got 2 Mixers (A, B)
These mixers can do 3 types of liquid (L1, L2, L3)
When the mix is done I need to pump the mixer (A or B) to one of these Storage Tanks (ST1, ST2, ST3 or ST4).

Here is the thing, in the best world I would have line and 3 flowmeters for each product (L1, L2, L3).

But my boss wants to use 1 pipe, 1 pump and 1 flowmeter for the 3 liquid.

Every time we use a new one we need to push all the liquid out with air or something to empty the more we can.

After this we going to clean the pipe with hot water.
Flush the pipe with air again.
And from there we would be ready for a new batch.

For the piping I would have 2 options: Going up with a 2" NPT pipe like 45 feet in the air or going straight for around 75 feet and coming down to the storage.

The other option I could see is to dig up the floor and put the pipe in the floor so basically from the pump it would go 2 feet down, then 75 feet straight and going 2 feet up to the storage tank.

That's prety much what my boss wants. I'm trying to work his idea, but a big problem I can see at the moment would be to push the liquid with air for cleaning or the batching liquid. If the pipe was on the floor I guess it could work, but 42 feet in the air? No way.

Also the pressure and everything to air blow the liquid I don't know much but I'm pretty sure it's not legal to use 100 psi like he would like to. I would need more info about this.

For the flowmeter I was thinking about a mass flowmeter because all the liquid will have a different mass.

So that's pretty much what I'm working on at the moment. If you have any suggestions or ideas for this application, let me know! Thanks.

It appears You are looking for a process solution; and have not stated what the product is or how much cross-contamination is acceptable to the process.

If on batch change you clean 75 or more feet of 2"pipe with hot water then you will have quite an end of batch wastage. I've seen steam cleaning of pipework for milk products, and if drained correctly does not require air clearing or drying. It is unclear why you believe pumping 42feet up is a problem with liquids.

I've seen pigging done on a 100mm (4") line - at end of batch a pig is pushed down the line by start of the new batch thus separating the two. There is a certain amount of cross-contamination which in that process was acceptable.

>I've seen pigging done on a 100mm (4") line - at end of
>batch a pig is pushed down the line by start of the new
>batch thus separating the two. There is a certain amount of
>cross-contamination which in that process was acceptable.

100 mm pigging are not so good for this.

>Here is the thing, in the best world I would have line and 3flowmeters for each product (L1, L2, L3).<

Once you hit your desired volume of product and you stop the pumping, are you planning on pushing all of the product in the pipe back to the storage tank or Is it wasted with the cleaning cycle? Either way, there is going to probably be some waste every wash cycle. How many batches are you running a day?

Would your wash system require high pressure air and water?

I would honestly consider the "best world" option of dedicated lines, flowmeters, pumps. Its more robust, highest accuracy, zero waste, zero chance of contamination, simultaneously pump all 3 products. I could go on..

If you determine the price difference between the two options, I'd be curious to know the ratio comparison.

Good luck

>But my boss wants to use 1 pipe, 1 pump and 1 flowmeter for
>the 3 liquid.
>
>Every time we use a new one we need to push all the liquid
>out with air or something to empty the more we can.
>
>After this we going to clean the pipe with hot water.
>Flush the pipe with air again.
>And from there we would be ready for a new batch.

Why do you need to flush the line After L1, L2 and L3? presumably you are adding L1 then L2 then L3. Can't the following liquid act to flush the one before? They are all going to the same mixer after all.

Why do you need to measure the flow from mixer to storage tank, surely its the same as Q-L1 + Q-L2 +Q-L3? Where would all the hot flush water end up?

I understand you may need to flush the flowmeter at the end of a batch but you may be able to skip some of the intermediate flush steps.

It seems to me the savings in only having one flowmeter would quickly be eaten up by the cost of complex valve and piping.