Right releaser for High Vacuum

[doocat]

Looking for info on the right releaser for 2000 on high vacuum (25-27)

Any ideas?

[caseyssugarshack93]

Id say a bernard or lapierre double mechanical or a bernard Electic releaser,

[Haynes Forest Products]

I like the two I have of the double Bernards and have not had a single problem with them under all conditions and trust me when I say I push most everything I have to the limit.

[jason grossman]

CDL has new mechanical releasers and a new electric where the pump is in the releaser either would be god for high vaccum.

[maplecrest]

about time they put a pump in the releaser. jason got any pictures of that new releaser?

[Jeff E]

I have single horizontal Bernards, with a 6000 tap listed capacity. It dumps I would guess at about 25 gallons.
Only 1 season with them, but they are very simple releasers, easy to clean and maintain, and dependable.
You can see pics in the photobucket link, the 2009 album.
By the way, I run about 24-25" of vac at the releasers.

[Mark]

I would also see a picture of the releaser with the pump inside. I was going to put a well pump in mine to stop all the problems at high vacuum and don't want to use a mechanical because of the air it lets in on every dump.

[jason grossman]

Sorry, i don't have any pictures of the new releasers. i saw them at CDLs open house in quebec in the spring. they were all stainless pumps. It was working and seemed to work well in there shop.

[Haynes Forest Products]

isnt the air that is let in at every dumping air from the lines so what is the concern?

[maplecrest]

the ice that occurs at high vac levels during sap runs at 29 degrees

[DrTimPerkins]

isnt the air that is let in at every dumping air from the lines so what is the concern?

No, the lines are under the same vacuum as in the releaser. Mechanical releasers need to dump in ambient air to break the vacuum and "release" the sap. The concern is that this can cause transient backflow of sap (especially in single-line systems), which introduces bacteria into the taphole. Essentially it's the same thing as a transient repeated leak.

[doocat]

Would a Stainless steel Surge electric releaser from a milk house work at those high vacuum levels?

[Haynes Forest Products]

Im starting to think of all the time I spent watching my releaser was for naught. Im still wondering how my double Bernard is letting outside/Ambiant air into the sealed chamber? I know there is a small back surge during the transfer from tank to tank.......dang another sleepless night.

[vermaple]

I agree with you Haynes, I use a Bernard single horizontal releaser and with the check valves closed between the lower and upper tanks and vacuum re-established to open the check valves, there is very minimal vacuum drop in the lines.

[DrTimPerkins]

I agree with you Haynes, I use a Bernard single horizontal releaser and with the check valves closed between the lower and upper tanks and vacuum re-established to open the check valves, there is very minimal vacuum drop in the lines.

Obviously this isn't the same for all releasers (electric pump models being totally different), but when the lower chamber fills with sap, it pushes a float arm up such that at some point air is introduced (that is the "whoosh" sound you hear as vacuum rushes into the lower chamber. The seal between the upper and lower chambers closes off because vacuum pulls the check valve between them closed. However, the entire lower chamber assembly gets filled with air at ambient pressure, so the swing gate valve opens and the sap is "released" and the sap can run out. If it were not at ambient pressure, but simply connected back into your vacuum system lines, the vacuum in the lines would not allow the swing gate to open, there would be no "release", and sap would never come out.

Most releasers in the maple industry either operate on differential vacuum pressure (breaking the vacuum in one chamber) to empty their contents, or they are designed to be pumped out.

So now you may be thinking....OK, so I let in what...about 3 gallons of air into the system....that's no big deal. Actually, it can be a big deal....because at 25" Hg vacuum, 3 gallons of air at ambient pressure (0" Hg gage pressure), the air molecules will be pulled away from each other so much that they will occupy 70 times the volume of the ambient air. So in this case, 3 gallons air x 70 = 210 gallons of air. So every time that releaser opens, you basically get a blast of about 200 gallons of air (and sap) surging backward through your tubing system.

You can see this happen when you watch your releaser (especially with a single-line system). Sap is running into the releaser in a reasonably steady stream from your tubing system....the releaser opens and the sap stream stops running in....the releaser closes, 10-20 seconds go by...and the sap starts running into the releaser again. Now the sap in your pipeline didn't just stop in one place and stay there. It is a fluid and is moving. It is either moving down towards your releaser (good), or is running up towards your woods (not good).

[DrTimPerkins]

...that is the "whoosh" sound you hear as vacuum rushes into the lower chamber.

Should actually read....

...that is the "whoosh" sound you hear as AIR rushes into the lower chamber.

TP

[Jeff E]

On the single bernard, horizontal releaser, there is the upper chamber where the actual mainlines connect to the releaser. I have a vacuum gauge on top of this chamber. Say I have 25" of vac on the system. When the lower chamber fills and starts the dump process, a valve on top of the lower chamber seals the vacuum line and opens the lower chamber to ambient air.
Imediately the 'flapper' valve between the upper and lower chamber closes, and the lower valve opens, dumping the sap. At this point the vacuum in the upper chamber is about 24", and sap is still coming in from the mainlines.

Once the sap dumps the upper valve on the lower chamber closes the opening to ambient air, and opens the vacuum supply to the releaser again. All this takes maybe 3 seconds! I would guess 25 gallons of air is introduced to the system, but only between the releaser and the vacuum pump. At this point, the vaccum gauge on the upper chamber may be down to 22" of vac. It stays seperated from the lower chamber until vacuum equalizes.
I have never seen my go below 21" of vac at this transition.

All this to say, I do not have dramatic loss of vacuum in my lines at dump time. Perhaps other releasers do, but the simple single horizontal releaser keeps good vacuum going to the bush.

[Mark]

Put an amp meter on your vacuum pump and watch the current jump when the releaser dumps. The pump has to work harder every time it dumps which is lost cfms to the woods.

Any one want to buy a 10hp sihi pump? I have a 20 hp two stage sihi pump that I am going to use this year.

[Haynes Forest Products]

Dr Perkins I know that Whoooooshing sound very well I was 1/2 way in the tank opening one day looking in the tank when I heard it. I understand that having the check valve as close to the area we want to protect that being the tap hole is the best most effective way to keep sap from backflowing into the tap hole. Would a check valve at the releaser and at mainline branch lines help reduce the reverse surge? I'm not trying to do everything BUT the best solution I'm wondering what the tests show? I would think that if your using a wet line dry line system and considering the math as far as expansion of the gases the dry line would be your biggest offender when it comes to exspansive surging.

Now Dr Perkins has me thinking about the effect that all this surging back and fourth has on the tubing system. Liquid shock to a water system over time will cause alot of differant problems to valves, seals, fittings even the hold down points. I was working at a golf course one day and they were pouring cement around all the elbows and Ts in the buried 2" and 4" irrigation system and was told that water shock from the liquid hitting the fittings when the valves shut would break them or force them apart. I would think over time the constant expansion and contraction will have a negative effect.

[Mark]

I use an electric extractor and it works ok up to about 24 inches and above that air starts leaking through the seal of the transfer pump and it won't prime.
I was planing on putting a well pump inside the extractor. But if CDL has a nice setup I would go with that. I would like to go up to 27".

[DrTimPerkins]

...air is introduced to the system, but only between the releaser and the vacuum pump...


Jeff -- That is a very good point and is correct to a fairly large degree -- thanks for that clarification. Not all the air that is introduced during the "release" makes it back into the system. But air is getting in somewhere if the vacuum gage transiently drops from 25" to 21-22" Hg. Three likely places are:
1. Gas (air) coming from the tree
2. Leaks in the woods
3. Air bled into the releaser.
Most likely it is a combination of all three, but if you're running 25", it sounds like you're doing a good job in the woods and probably don't have many leaks out there. There isn't that much gas being produced by the trees. Therefore, we're left with only the releaser as a source for the vacuum drop.

When you get that vacuum drop, the sap does stop running into the releaser for a period of brief time (a few to 10s of seconds) during the "release". This means there is a pulse of sap running uphill in your system. Releasers make a lot of these small, transient pulses that are system-wide, whereas tubing/fitting leaks result in variable amount of sap movement depending upon the size and location of the leak, but are often localized within sections of your system...unless they are catastrophic leaks down near your sap shed in near the bottom of your collection system.

As for the question about where to put the check-valves....if the object is to prevent sap moving back into the taphole, the BEST place is to put the valve as close to the taphole as possible. Thus we choose to put it in the adapter. However, our patent does cover check-valves anywhere from the mainline to the tree. Putting a check-valve in a mainline will help with the releaser surges, but will not help with a leak anywhere else in the system. At the same time, making incorporating the Check-valve into an annually replaceable adapter means that each year you are putting a new (and clean) spout...the interface between the tree and tubing system....into the tree.