Cooling Liquid Ring Pump

[Amber Gold]

I'm trying to think of ways to cool the water for my liquid ring pump. I'm going to have (2) 150 gal stock tanks for cooling water and will have no outside source of water to pull cold water from such as a stream.

Never having a LR pump before I'm not sure how much heat they generate. The pump curve is shows best performance for water temp. <70F. I want to stick with water because it's free. If I leave the pump running 24/7 do I need to worry about the pump freezing at all? It'll be inside the unheated SH.

One idea I had was to run 100' of 3/4" hose in my 40'x10'x5' snow bank, but determined there's too much chance of having a line freeze or being damaged and leaking.

Another idea I had was to go to the junk yard and pull a radiator out of a truck and plumb that in. Would a box fan provide enough air flow over the radiator to cool the water?

To cool my Delaval 73 pump last season I just used an 8" desk fan blowing on the pump and it made a huge difference on the pump temp. Would I be able to do the same thing with the LR pump and have it be adequate?

Any other ideas?

Thanks in advance.

[mtnmeadowmplfarm]

An easy way to ensure your pump doesn't freeze is to insulate a small area with blue board for your pump to sit in and hang an incandescent lightbulb in there. In freezing temps, heat from the lightbulb will be sufficient to keep the pump from freezing. I have heard of people using radiators to aid in cooling their pumps and it works fine for them.

[DS Maple]

I visited a guy last season who was running to large sihi pumps and cooling them almost entirely from a 250 gallon (give or take) tank that held the water being recirculated. He did however have tiny (like 1/8" or so) lines coming into them from a stream. I guess I'm thinking that if you have 300 gallons of water and it's cool enough outside you might (key word) be alright. The guy I talked to though did drain the pumps whenver they were shut off. Maybe you could get around this by just running it all the time. Don't take my word though. These are just thoughts and I don't want you to ruin your pump.

[maplecrest]

amber, if you go the radiator route. use oil instead of water. the way of the new movement is oil cooled not water. get a rad. and a electric fan to blow thru the rad. get one big enough to act as the resivore the pump will circulate the oil and fan to cool it. or if you want to do the water loop in the tank you need to intoduce cold water to keep the pump head cool. the warmer the water the lower the vac level. the colder the water the higher the vac level. as stated a 5/16 line of cold water into the pump head as well as the water circulating from your tank back to tank will work. the problem for drawing from a brook is 5/16 line will freeze at nite. and the water in your tank will heat up. in past posts theron talked about ice in a row boat to cool his pump to keep his vac level.

[Haynes Forest Products]

If your going the oil route and you want to make a big cooler get a cheap tote dirty ones are even cheaper and you can wind 1/2 or 3/4 poly sprinkler pipe in the screw cover hole. Take a 400 foot spool and just wind it in. Put 90 degree fittings on the ends so you can have the ends come out stright. If you want to get fancy use bulk head fittings. Fill with water and let it freeze every night who cares. What is the GPM rating on the pump and what is the max heat that it can take? I cant believe that you will overheat 250 gallons of water with oil running thru it in 16 hrs. For $200 you could make a heck of a cooler.

[Amber Gold]

Outside water source isn't an option unless I pull water from my well. I was thinking of running them 24/7 during the season. Doing this I'm not sure how long it would take to heat the 300 gal of water up, if it would at all. Running the pump alone it'd cost about $5 per day to run at 230V and 5.5 amps (I think)...not a huge expense.

Maplecrest, I did read Theron's earlier post and there is a pond down the street I could cut chunks of ice out of. Probably not a bad idea...it'd keep the water about 32F. i was going get a radiator out of a work truck or something with a large radiator. About how much oil would I need and what type of oil would I use? Aside from not freezing, what benefits are there to using oil?

Trying to find something as low maintenance as possible...one less thing to worry about during the season.

[maplecrest]

working that detail out myself

[Amber Gold]

Please keep me posted with what you find. I still have plenty of time to determine what I'm going to to do.

[mountainvan]

I've heard of someone burying pipe in ground, a couple hundred feet, like a heatpump but shallower. Filling the pipe with oil, and using that loop to cool the pump. I guess the heat dissipates into the ground. Not sure who. WMF on here knows more.

[Spike]

Amber, Iran into the same situation last season with my new a20. I solved it by cooling the pump with anti-freeze 90/10. Think of it as a car engine. Kept it cool. An I ran the pump for days. Howard











AmQUOTE=Amber Gold;82269]Please keep me posted with what you find. I still have plenty of time to determine what I'm going to to do.[/QUOTE]

[Haynes Forest Products]

looking at the video and the size of the water line and the size of the tank I cant amagine that you would over heat the water in a tote. Is the impeller steel or rubber?

[Amber Gold]

Howard Is that 90% water and 10% anti-freeze? Did you have an outside water source bringing in cool water, and if not, what did you have for water storage?

Another thought. I have a 600 gal. bulk tank with cooling lines in the shell. Would it make any sense to run the pump water through these cooling lines? The only downside I could see is slightly heating up the sap and possibly increasing the bacteria content. Thoughts??

Haynes, it's a 1" inlet/outlet adn I think it's a 1 or 1.5 gpm pump.

[Haynes Forest Products]

Did a little internet checking and as far a cooling liquid concerned water, oil even solvents could be used for cooling. The seals are the determaining factor so a call to the factory will be best. 60 degree F is the best operating temp and then its downhill from there.

I would think that due to the fact that after you drain the pump every night you need to prime it before start up that antifreeze or oil would be a better set up. The manuf. mentions that scale can build up in the pump due to dirty water/Calcium and rust will cause problems so Im thinking a closed system with antifreeze would be best. I have seen some nice heavey duty radiators with 2 cooling fans at junk yards that could be run with step down transformers that would help in the cooling cycle.

The chart that I saw said the smallest pump needed 3-4 GPM so that would warm up alot of water over 16 hrs I would think. laying cooling lines in a snow bank works for about 1 hr before all the snow shrinks away from the tubing and your only using air temp after that.

[vermaple]

I know absolutely nothing about liquid ring vacuums, but the first thing I thought of reading this thread is what is the danger of cross contamination from cooling liquid into the vacuum system? Hence the reasoning behind using water for cooling?

Probably no more so than an oil cooled pump, but the question entered my mind.

[Haynes Forest Products]

The vac pump is the last thing in a long line of equipment so its not likely that anything can get to the sap I would make sure that you have a spring loaded check valve between the pump and moisture trap.

Basicly a liquid ring vacuum pump gets its name from the liquid that is sucked into the pump housing and sentrifical force keeps the liquid in a "LIQUID RING" on and in the impeller. The liquid is what cools the pump AND makes the seal between the impeller and the pump housing. Without the liquid the pump will not make vacuum and will overheat.

[Spike]

Amber I have no water source. on a 3 by 6 pressure treated covered skid, I have a 35 gal tank . In that tank there is 18gal of 95% antifreeze 5% water. Also there is a radiator with a fan. Small VW type will do. The pump will pull the anti out of the bottom and circulate. The path is tank radiator to pump. The unit can be left out doors to -35 degrees. The pump stays cool even after days of 24-7. These types of pumps are made to run at 50 degrees for years at a time with out turning them off.

[PATheron]

My deal is kind of like Spikes only I dont have a radiator. I just have a tank with antifreeze solution with line that runs out on the ground to the pump and the pump sucks it through the line. I try to place the line in the snow, etc, or like I said last year I threw it in my rowboat and threw ice in it now and again. Im kind of still working on a better way myself. Theron

[WMF]

I would advise against using ethylene glycol (automotive antifreeze) as the risk of contamination is real and won't be noticed like oil will.
Propylene glycol works well and is much safer for everyone including pets if spilled. Dairy supply businesses usually have 55 gallon drums of it and it is relatively cheap.
A two horse liquid ring running at 26" will heat up 20 gallons of water within a couple of hours without a heat exchanger and the pump capacity will fall way off. Also if the water gets warm (> 60 degrees) it will evaporate faster than you think.
On a tight system with cold service liquid you will actually gain liquid as water vapor from the tubing system is condensed by the pump and will end up in your cooling tank diluting your antifreeze.

[Amber Gold]

WMF, Do you have an approximate cost for the 55-gal drum?

Spike, Why do you run it at 95&#37; glycol and 5% water? Sounds like an expensive way to get freeze protection. TSC carries RV antifreeze for $4 a gallon. What about running a 50/50 mix? 35 gal of antifreeze is getting pricey.

Theron, were you just running your line through the row boat or using the row boat as your tank? How often were you adding ice to it?

Thanks

What works better for keeping the pump cool, oil or water? If using oil, what type of oil do you use?

[WMF]

Amber,
It was $7 or $8 per gallon for concentrate which could be diluted with water 1:1 and still give freeze protection. The pink RV antifreeze that I have tried had a weird smell but the concentrate is colorless and odorless and is food grade.

The biggest advantage of oil is because it has a high vapor pressure it does not readily turn to vapor when warm and the pump will still perform well at moderate ( < 115 degrees) temps. Liquid ring pumps on oil will emit some smoke similar to a vane pump.

You should be able to get by with 4 or 5 gallons total of liquid if you cool it with a air to liquid heat exchanger.

[KenWP]

A small amount of anti freeze added to water will make sure the water dosn't freeze solid. As long as water can not freeze solid it will not swell and break things. We use 50-50 mixtures up here for up to and believe me I have been there -50 weather. I had to change all the boilers around to gycol a few years ago because we started to get staff that didn't know what winter was and cold and everything kept breaking. I seen a guy hook a hose to the one boiler and wash the floors with it and it sure made them shine.
You could also hook a old radiator to the line and sink it in a tank of water and it would increase your surface area several times. Then try the ice idea to keep the water cool and if you shut it down at nights it will freeze up and you will get that much extra cooling the next day.

[Amber Gold]

WMF, I did a quick search online and found a company that sells it for about $10/gal shipped. If using oil do I need an oil reclaimer? What type of oil do I use?

At this point I'm leaning towards getting a radiator w/ fan (maybe a box fan), 50 gal barrel, and 10-15 gal of concentrate to mix a 50/50 solution. Either that or oil...haven't decided which yet.

[Spike]

Amber, I dont have 35 gal. of anti freeze. Just a 35gal poly tank with 18 gal of 95/5.

[DS Maple]

If you plan on cooling with oil you need to make sure the seals on the pump are designed to take it. I know Bascom's ran into an issue cooling some of their Sihi pumps with oil running through one of the CDL radiator systems. The pump seals weren't designed to hold oil and thus allowed it to leak out and make a huge mess. They constantly had to clean up around the pumps and add to the oil level. As a result they did the research and upgraded to larger Sihi pumps that have seals capable of retaining oil or water.

[Haynes Forest Products]

The Sihi online manual says that if you want to cool with oil to check with them to get the right oil for the seals that your pump has. Like most used equipment you dont know what it was specked out for so its best to have the model and serial no. so they can tell you what type seals is in it. They say you can use solvent as a coolant so I would think they have a long list of seal types.

[Amber Gold]

I contacted Tuthill Tech support about how to best cool the vacuum pump and different ideas. This is what he said:

A 300 gal tank w/ a 1/2" pump water supply line pumping at 2.5-3 gpm will work for conditions less than 50F. The pump will keep the water warm, but it shouldn't get too warm.

If a smaller tank is desired, say 25-40 gal then some form of a cooling system should be used.

He said the split he sees is 25&#37;/35%/40% water/water-glycol/oil.

If oil is to be used, then a lightweight oil is needed, either 5 or 10 weight...not motor oil.

If using water-glycol then a 50/50 mix is fine.

[gmcooper]

I have a 35 cfm 7 hp liquid ring pump from Art Harris at Indiana Vacuum. It uses a 35 gallon poly tank and 100' 1" black pipe as a cooling loop. My cooling loop is only on top of ground not buried but usually covered with snow much of the season. I use a water antifreeze mixture good for -20. It ran 24/7 part of both years and on warmest days water may have gotten into 70's. What ever you use to cool with make sure it is compatable with the seals in your pump.
Mark

[Bradenfish]

Windshield washer fluid would work wouldn't it? I just saw some at TSC 1.99 for a gallon of -20*.

[Haynes Forest Products]

Bradenfish It likes to evap at a high rate so keep it in a closed loop. How about RV anti from TSV?

[KenWP]

Windshield washer fluid would work wouldn't it? I just saw some at TSC 1.99 for a gallon of -20*.

Problem useing windsheild anitfreeze is when you heat it your going to get a pressure surge on the cooling fluid in the closed loop. Just use normal anti freeze or RV anti freeze. Windsheild anti freeze is alcohol and not made to heat up.