Suds pump

My Nephew works as an Air Conditioning engineer. Recently I was looking at some of his stuff and there was a little pump that pumps the condensation out of the overhead air conditioners.

Being a fluid pump running on 240V I thought it would make a verty nice suds pump. He had others that had integral reserviers but were a bit big for the purpose of suds pump, they were peristaltic type pumps.

Perhaps if you are looking for a suitable pump keep an eye open for a defunct air conditioner.

Clive

good call Clive

I've got two brother-in-laws in the refrigeration and AC trade so I'll ask them to keep an eye out

Air conditioners produce a lot of condensate, often there is a small plastic sump with a magnetic float. When the float rises it operates a reed switch causing the pump to run. An old aircon pump may have issues, the silicone rubber peristaltic tube often is OK but it is plugged into a plastic pipe assembly which tends to break up after many years. You can fix the pump by replacing the plastic pipes with brass tube. The motor is normally a small shaded pole job with gearing down to around 100rpm. Regrease the gears and soak the shaft bushes for another ten years of life.

If you are in a DIY mode peristaltic pumps are easy to make if you can get some suitable silicone rubber tubing and a slow running motor. No valves, always self primes and will deal with all kinds of stuff that would jam other kinds of pumps.

(Have bodged quite a few aircon pumps, got fed up with paying silly money every time another old pump leak flooded the ceiling, refurbished all of them for less than the cost of one service call.)

Billy.

Good call BUT, I used one with its pkastic resevoir for a couple of years before the peristaltic tube gave up as it was impregnated with small shards of metal. Replaced the tube and again it failed a year or two later. By the way, you have to do a bit of re-wiring of the float switches, but its not difficult.

You do need a realy good filter before the return pipe from the lathe / mill etc.

I now use a small indoor pond pump - but it doesn't have much of a head.

On the single phase lathe, I have a 3 phase dual voltage suds pump, running on 240v single phase. Connect live and neutral on two of the terminals, and a capacitor across the other two. Ok you loose 60% of the power, but there is heaps left for the pump.

I use a windscreen washer pump. They are a gear pump and have a DC motor so the speed and thus the flow rate can be varied by adjusting the voltage. Been OK for about 8 years now.

Russell.

Gentlemen,

I service equipment using Perastaltic pumps which run for 6 seconds every 6 mins 24/7 365 days a year and the silicon tubes last at most eighteen months, if the pump is not used for a period of time the pressure from the rollers on the silicon causes the bore to stick together and they cant be recovered. I wouldnt use one for pumping suds.

Martin P

Martin, you didn't say what was being pumped. In our aircon application we have 20 pumps which have been used for over 14 years. They are pumping dust containing water. Four of the pumps are in a server room which runs 24/7. The building was empty for 18 months without the rollers moving. No tube issues at all. The tubes are thin walled, the roller pressure is just sufficient to close the tube.

Billy.

Billy,

Sorry should have said, one pump has a very weak mixture of Bicarbonate of Soda and water and the other is a very weak mixture of salt and water. The water can either be RO or city water depending on the customers needs and the tube wall thickness is 2.5mm.

Martin P

I've got a preistatltic pump which, apart from a few blockages and sudden rushes has worked 100% for the last 50 years on the same tube. I'm hoping it's good for a few more decades yet.

Neil

God bless your colon Neil. I have had a couple of views inside mine and a bit of maintainance in the bore, so far so good. The pink tube is pretty clever but it is the weirdest thing when you watch a monitor displaying the trip through your own pump. Glad they clean the fibre optic tube between uses!

Just happened to see that Mike Cox had an article in MEW 181 Oct 2011 for a suds system- he used a windscreen washer pump.

Billy.

I have built a coolant system using a windscreen washer pump. The design was inspired by the Mike Cox article mentioned above.

I used to keep Marine Fish in a previous life and there are a variety of submersable pumps and something called RO tubing. My guess is that suds can't be as toxic as salted water.

Here is a link you can use larger fittings if you want.

There are many small submersible pumps and switches in the aquarium section of ebay.

Submersible Pump

Float Switch

Mention was made earlier about metal and detritus damaging pumps. All the suds pumps I have ever used have all had double bay sediment tanks where the raw suds with contaminants settles and wiers over into the small bay where the pump is situated.

It should be easy enough to make up a stainless filter baffle to catch a lot of the muck but it will clog up occasionally.

The pump I picked up was not peristaltic, it is gear driven and very small akin to a pump for an aireator in an aquarium.

My idea was just to pump up to a small header tank and then have a drip feed to the work.

Clive

Inevitable I suppose ... but it's unfortunate that this thread and another recent one have not been cross-referenced in some way.

May I encourage everyone to do what I have just done; embed references to threads containing "prior knowledge".

MichaelG.

Hi There

I can combine threads if they are not too long.

(I can do long ones but each post has to be moved individually.)

What threads do you want combined?

regards David

David,

Many thanks for the offer, but I doubt that you need to combine the threads.

I just happened to note the similarity, and though it worth inserting a reference.

MichaelG.

Edited By Michael Gilligan on 19/07/2012 09:38:59

These do the job well. At that price it's not worth the time to make one.

Russell.

Oops! I linked to the wrong thread. the one I meant to link to is HERE

Its clear there ARE tubes that would have the required life:

"Another one claims "At a back pressure of 4 bar (60psi), this pump tube lasts over 1,000 hours with continuous use at 200rpm in a Watson-Marlow Bredel 700series pump. Under transfer conditions, it exhibits 18 times the life of silicone rubber tubing, and nearly twice the life of thermoplastic elastomer tubing with continuous pumping at 360rpm. The risk of premature tube rupture is significantly reduced"

These are tubes with strengtheing fibres, that's 3 years at 3 hours a day and high speed. Apparently the key to long life is avoiding over-compressing the tube.

Neil