Electric Extractor/Releaser Questions

[twofer]

Just picked up my D&G vertical electric releaser and already have some questions. :)

1. Should there be a check valve between the releaser and the pump? The dump port is open and it seems like it would have a check valve on it to prevent the vacuum from drawing through the pump.

2. How do you calculate the effective of vacuum on the feet of head for the pump?

Thanks

[Haynes Forest Products]

Sounds like another peice of maple syrup equipment sold that doesnt come with instructions:mad:

[Thad Blaisdell]

There should be two check valves.

Releaser connected to the pump. Out of the pump a "T" the top goes back to the top of the releaser smaller pipe with a check valve. Out of the side of the "T" you will have a check valve and then send it to your tank.

I think this is right, without going to see how I have is set up.

[Shaun]

What HP pumps are you guys using on electric releasers? Say one that is rated for 2000 taps 30 inch vertical. Starting with a dairy pump for now 15-18 inches of vac.

[BreezyHill]

The pump needs to sit in sap when running...so the check needs to be after the pump and as close to the pump as possible to have the most flow; while limiting area for sap to freeze. The affect of the vacuum on the pumps head rating is limited as long as there is no entrapped air in the pump. The wrong style of check valve will have more of a limiting affect on head.

Ben

[wiam]

The pump needs to sit in sap when running...so the check needs to be after the pump and as close to the pump as possible to have the most flow; while limiting area for sap to freeze. The affect of the vacuum on the pumps head rating is limited as long as there is no entrapped air in the pump. The wrong style of check valve will have more of a limiting affect on head.

Ben
I agree with this if it is a submersible.

[claytski]

I disagree with this statement and this is why:

The difference in pressure between the suction and the discharge of the pump represents the head to overcome. This would not be limited but be an actual quantifiable number. For instance, if the outlet of the pump were modeled as a free jet and there was no head to overcome to get to a tank, the head would be the difference in the vacuum and the atmospheric pressure at the given location. Regardless of the pump being submersible or not there is still head to overcome to move fluid out of the vacuum environment.

When I am building and designing releasers for customers I use a rule of thumb I developed. The rule of thumb I use for sizing pumps generally accounts for pumping up and into a tank. There are a few customers that have asked for special applications where they have over 100 ft of head to overcome in addition to extracting sap from the vacuum environment.