Compressor loading, overheating, failing
Canister and Controller for air powered water pump
I manufacture air powered water pumps. They operate on the principle where air pressure is exerted in a canister full of water. The air pushes on the surface of the water. A delivery pipe extends almost to the bottom of the canister. The water is forced down and up the pipe.
When the canister is almost empty, an exhaust valve allows the remaining air to be vented to the atmosphere, allowing the cylinder to refill and the cycle is repeated.
I have a problem with one installation where the water is only being lifted 15 metres.
He only has single phase power and this limits the size of compressor he can use.
The result is that the compressor is overheating and blowing head gaskets.
The compressor manufacturer reckons that the problem is that as the air does the work of pushing the water, it is not being expelled into the atmosphere and this is creating excessive back pressure, creating the overheating problem.
Do you think this is correct? ( the higher the water is pumped, the longer the pump period has to be as it has to get the water moving from stationery each cycle).
Any advice you can provide would be appreciated.
Kevin, I'm puzzled that the air compressor does not appear to have a thermal safety switch, which would cut the motor power in the event of a too high temperature rise, and shut the motor down before damage could occur?
Am I correct in assuming that the water, once pumped down the line, exits somewhere, or is it going into a closed system.
When the water in the pump is blown out, what shuts off the supply of air to the pump, and does the compressor simply run without air outlet at that point? If so, then the compressor manufacturer might be right, although, I still wonder about the absence of the thermal safety.
If the air from the compressor is deadheading, and the compressor is still running, could you not put a diverter valve in before the pump that would allow the air from the running compressor to blow to atmosphere while the pump is filling, and then switch back to filling the pump when it has been filled with water?
Anyone else want to chime in on this neat application for compressed air?
Kevin, if you want to add more to this, or anyone else, please click on the comment button so your input stays with this post.
Measure compressed air flow rate?
by Dave Hinder
(St. Catharines, Ontario, Canada)
Trying to determine consumption into various lines.
Are there any portable "quick-disconnect" type flow meters?
Hello Dave. Welcome to you and the other folks that visit from St. Catharines.
Any in-line flow meter can be set up as a quick connect.
You will want to install it where an existing air line enters a fitting. Perhaps on the valve power line etc.
Add an instant fitting to both sides of your flow meter. To the upstream fitting add a length of poly tube that's the same diameter as the existing line.
Then, when you disconnect the existing air line from the valve or other air using appliance, you simply insert the tube from the flow meter into that fitting, and insert the existing disconnected line into the downstream fitting on the flow meter.
With this rig you can insert the flow meter into the feed line anywhere you wish and monitor the flow to a specific use.
If it's a probe type compressed air flow meter, the test rig will include a Tee, a line running up out of the Tee into which the probe would be inserted, a length of tube from the upstream side of the Tee to plug into the air source fitting, and an instant fitting on the downstream side into which the line to the air using device can be inserted.
Where to get compressed air flow meters?
I know these guys have a pretty slick series: http://www.vpinstruments.com.
Or, use your browser to search for "buy compressed air flow meter" and you will turn up lots.