Pump System non PLC control

[Stationmaster]

Gotta side with the "toilet tank" camp here. 100 gallon tank fills all the time automatically, then flushes just like a toilet tank each time the operator pulls the handle, flaps shut when empty, and refills whether he's there or not...

1 bag, 1 flush. The technology is available on isle 8 of your local home improvement store.

1 note, you may have to set the level to be LESS than 100 gallons to account for the water that flows into the toilet tank WHILE it is flushing, depending on how fast it flushes, and how exact you need the 100 gallons to be...

Stationmaster

 

[Lancie1]

Staionmaster, that will work, provided he has room and money to add another 100 gallon tank. Because he is mixing in a tank that is constantly being emptied, then he can't easily measure out the 100 gallons in that batch mix tank. If he has to live with only the tank he has, then that kind of narrows it down to adding some type of flowmeter with shut-off valve to the water line.

If I were doing this for the usual process plant, I would put in a flowmeter, with feedback to the PLC, an operator graphic panel with setpoint (set to 100 gallons), and a solenoid-controlled water valve that drops out when flowmeter = 100.

Tom, if accuracy is not a problem, I have a battery-powered sprinkler-hose timer that I bought at Lowe's for $30 (for my rain-barrel system) that allows setting water flow time in a 5/8" hose line. If you can measure how long it takes for your normal pressure and line size to flow 100 gallons, then that might get you within + or - 5 gallons. Sounds like your accuracy is not a great concern anyway. But you really need a larger valve. Probably 10 to 15 GPM is all you can get through this sprinkler timer.

 

[Lancie1]

That looks like something that would work. I think the
LAMBDA-SA Semi-automatic Batch Control Unit is what I would be after.

Do you know who the distributor is in the U.S.?

I don't think Lambda has a US distributor.
Still, you would need a solenoid valve, on/off switch, power supply, enclosures.

Here are some other possibilities:

Manual Faucet Flowmeter Water Timer
http://www.qvc.com/qic/qvcapp.aspx/...l.detail.msn_refer.false.item.V108654.ref.CJ4?

Electronic Flowmeters from 15 to 2500 GPM
http://www.doheny.com/catalog/product/view/id/2241/s/Electronic-Flowmeter/?___store=default

Carlon Batch Controller:
http://www.carlonmeter.com/index.php?q=batch

DLJ Batching System
http://www.jerman.com/batcher.html

 

[michealthomas]

Use the KISS theory Keep It Simple Stupid

 

[robcontec]

Staionmaster, that will work, provided he has room and money to add another 100 gallon tank. Because he is mixing in a tank that is constantly being emptied, then he can't easily measure out the 100 gallons in that batch mix tank. If he has to live with only the tank he has, then that kind of narrows it down to adding some type of flowmeter with shut-off valve to the water line.

If I were doing this for the usual process plant, I would put in a flowmeter, with feedback to the PLC, an operator graphic panel with setpoint (set to 100 gallons), and a solenoid-controlled water valve that drops out when flowmeter = 100.

Tom, if accuracy is not a problem, I have a battery-powered sprinkler-hose timer that I bought at Lowe's for $30 (for my rain-barrel system) that allows setting water flow time in a 5/8" hose line. If you can measure how long it takes for your normal pressure and line size to flow 100 gallons, then that might get you within + or - 5 gallons. Sounds like your accuracy is not a great concern anyway. But you really need a larger valve. Probably 10 to 15 GPM is all you can get through this sprinkler timer.

Lancie1,

You are right I neither have the room nor the capital for another "Toilet Tank"

My original thought was a lawn sprinkler system type valve. Though one has to see other options.

My current PLC that is running the system besides being a PLC 5/11 is already taxed beyond its limits.

The whole system is scheduled to be replaced next year and the lime slurry is going away.

I did think about adding a plate that the operator would stand on and if he left before the water was added, he would recieve a mild electrical shock, but for some reason management frown on that solution.

I'll check out those other links.

Thanks everyone.

Other ideas are welcome

 

[silva.foxx]

Why do people find the need to over-complicate things, especially when it's going to scrap in the near future?

The operator needs to remain at the mix until the water is added so provide something to keep him there:

a hand valve that returns to closed if loosed go of

a solenoid valve that is activated with a constant push-of-a-button and closes on release

or... cement his workboots down!

 

[muusic_man]

Simplicate not complicate.

Why does the operator walk away? Is it behavioural?

If it's a manual process then why not have a valve that has to be held open by the operator?

Or tie the operator to the valve. Threaten to dangle him over the tank if he walks away again!

.

Why do people find the need to over-complicate things, especially when it's going to scrap in the near future?

The operator needs to remain at the mix until the water is added so provide something to keep him there:

a hand valve that returns to closed if loosed go of

a solenoid valve that is activated with a constant push-of-a-button and closes on release

or... cement his workboots down!

Ok you guys. Knock it off. Our jobs are to automate things so that operators don't have to do everything they are told. If it were not for people not following procedures, we would have less work.

 

[Lancie1]

For every bag of lime that is added to the slurry tank 100 gals of water needs to be added.

The issue is that the water is added by an operator opening and closing a valve.

The problems is that some times the operator gets called away and doesn't shut off the water (I'll only be gone a minute).

Why do people find the need to over-complicate things, especially when it's going to be scrapped in the near future?

Good point, Silvafox. Perhaps we are looking at the problem from the wrong attitude - trying to find ways to automate the water measuring, when there already is a way to do that - a guy turning a valve.

The real problem may be that the filtration process goes ahead even if the water has not been added, or if too much has been added. How difficult would it be to put in a pushbutton that signals "Water has been added", and not allow the system to continue until that button has been pressed?

If too much water gets put in, what is the fix? Do you just add more lime, or do you have to dump the batch and start over?

 

[Lancie1]

The operator is either a Lab tech or a syrup operator. He doesn't necessarily walk away but is called away for some other issue.

If he has time to work on other issues, then your 100-gallon water fill must take several minutes. In which case one of the simple sprinkler timers may work great. At 10 gallons per minute flow, it would take 10 minutes to put in 100 gallons. How does that compare to your current fill time - more or less?

The sprinkler timer that I have is an Orbit Model 27729, and requires three initial steps (for a batch operation): Turn selector knob to "AUTO", then press "MANUAL" pushbutton. Now enter Manual On time in minutes (0 to 240 minute range) using + and - buttons (default is 10 minutes). The valve opens and stays open for the number of minutes set. For subsequent batches at the same set time, it is necessary to press the Manual pushbutton again and reset the Manual On Time (unless it is the default 10 minutes). The large digital display flashes every two seconds between current clock time and Minutes Remaining of Set Time.

http://www.orbitirrigation.com/products/Timers/01/01/

It also has a clock for the automatic timed sequences that can be set to repeat every 6 hours, 12 hours, 1 Day (24 hours), 2 days, and so on up to 7 days. If you don't set a Start Time, then the Automatic operation is not enabled.

 

[Clay B.]

Reading this it seems right now this is not a very precise system. Since you do not have a budget or room for a shot tank then your options become pretty limited pretty quick. So Lancie's suggestion of soemthing time based is probably going to be you best solution. Really all you need is a timer a relay and a pushbutton.

Operator sets the time for how many gallons they want. You can figure this out prety easy. Heck I would probaly create a sheet that says x amount of time = x gallons.

Then pressing the pushbutton triggers the timer to start and there is your shot of water.

Not sure how much the sprinkler timer Lancie mentioned cost but using the timers, pushbutton and relay plus a box from Automation Direct and this project could be done for around $200. Probably less.

The fun part is figuring out the gallons per minute. Unless this water is coming out of a silo I doubt the flow is going to change much anyway.

 

[Lancie1]

Not sure how much the sprinkler timer Lancie mentioned cost....

The Orbit Model 27729 was about $30 (without the 2 AA lithium batteries) at Lowe's back in March 2010. Orbit also makes mechanical timers (no batteries) which should cost less.

Edit: Just looked on Lowes.com and the current price is $32.95 for Lowe's Item #: 159978

 

[robcontec]

I think I'll go with the orbit, it sounds like just the ticket.

I don't think I'll bust qualities budget with that either

 

[Lancie1]

I just went outside and run 2 flow tests on the Orbit Model 27729. At 45 PSI pressure, it filled a 5 gallon bucket in 55 seconds. That calculates as a flow rate of 5 x 60/55 = 5.45 gallons per minute. A higher water pressure would result in a higher flow rate. This is at a faucet fed with a 1/2" copper water pipe. A larger water feed pipe would also result in a higher flow rate. The Orbit has a intake screen built into the rubber hose washer. If your water is clean, you could remove the screen and replace that with a regular hose washer and increase the flow rate.

At 45 PSI, it would take 100/5.45 = 18.33 minutes to put 100 gallons into your slurry tank. This timer only has 1-minute increment settings, so you could set it for 19 minutes, and if the operator comes back before then and sees that he has the 6" gain in the tank, then he can turn the timer to OFF. Otherwise, if he is not back, it would cut off after 19 minutes (approximately 103.64 gallons).

 

[milldrone]

Lancie1,

I just went outside and run 2 flow tests on the Orbit Model 27729. At 45 PSI pressure, it filled a 5 gallon bucket in 55 seconds.

If memory serves me correct, aren't you running on a ram?

 

[Lancie1]

I was using a ram pump for my household water, and the water pressure there was only 20 PSI. I sold that place last year and moved to town. My health was bad, my wife wanted to move, and the maintenance on 175 acres was more than I could handle. The new owner was fascinated by and is still using the water ram pump. I suspect it will run at least another 50 years.

PS: I did ask for lifetime rights to the spring water. I have about 20 gallon jugs of drinking water that I keep in the garage. It is about time for another "water run".