Long or short cycle on releaser?

[MT Pockets Producer]

Looking for some input on which is more efficient in the long run, a short or long cycle time on a releaser? My original thought was it would be better to have more sap volume before it releases so there would be less time building vacuum after the release. But playing with the float I noticed that if I adjust it to cycle sooner I still have some vacuum left in the releaser when it stops dumping, so it takes less time to build back up. Less cycles building more vacuum vs more cycles with less vacuum build. Any thoughts? The more cycles with less sap volume would also let me bring my inlet down so the main comes straight in. Currently I have about a 1 foot ladder straight up before it goes into the releaser. It is a homemade releaser and the inlet has a swing valve on it to prevent vacuum loss back into the lines. I've seen some talk on here about priority circuits and that might be in the future also. These questions came about when I was making adjustments to the float as it was not releasing when it should have. It would be about ready to release and the vacuum would start to drop a few inches and then it would just sit there like it was stalled. I could see the sap trying to come up the ladder at the releaser but it would take forever. I would really like to get rid of that if possible. Oh, this is built with 10 inch pipe so even with the shorter cycle I think I would still be looking at 2.5 to 3 gallons per release.

[nymapleguy607]

If your losing vacuum in the time it takes to dump the releaser you have a pretty decent leak. The dump cycle should only take a few seconds to complete.

[BreezyHill]

IMO you have a couple of things going on that may have been over looked.

The higher the vacuum reading in inches of Hg the harder this is to achieve due to there being less air to remove. It is much harder to get that last 2 inches of vac than the prior two inches.

Now factor in that you are lifting the sap up just prior to the releaser and this difficult task adds to the hardship.

Picture pouring a 2 gallon glass of water out of a 1" opening on a pitcher vs sucking that same 2 gallons up a 1 inch straw out of the same pitcher. Much harder to over come the gravity than if the water simply flowed down to the glass.

I am a supporter of ladders to get sap harvested. But it must be said that if you have a choice of working with gravity and having a line sloped at only 1% and working against gravity and lifting sap 3'...it is far easier to work with gravity. Ladders are simple but it is still work.

Dump time is less important if the tubing system is maintaining vacuum. If you are losing even 2" during your dump cycle you are creating an issue of sap running back up the tubing system. This adds more hard ship as you have more air to evacuate to get your system back to your max reading again.

Every dump cycle you are having to bring the releaser form 0" of vac to your systems vac reading to get sap to enter the releaser from the tubing system. So if your releaser is a 4 gallon chamber you will consume just over half of a CF every cycle of the releaser. It will not matter if your releaser dumped half a gallon or 3 gallons your Cubic Feet per Dump (CFD) is the same; since the chamber will be empty at the end of each cycle and at no vacuum.

CFM (Cubic Feet per Minute) capacity of your pump is a large factor as is how quickly the system can evacuate the releaser. The larger the diameter of the line from the pump and the shorter the length of the line the faster the evacuation process. The other option is to have a oversized line that will act as a balance tank to equalize the chamber quickly. The smaller the pump the more advantageous a balance tank is.

The goal is to limit the drop of your tubing system's vac reading to 0" during the releaser's dump cycle. This is accomplished thru the use of different designs to achieve a quick recovery of the releaser. Design options of:

Priority circuit
Balance tank
Proximity of the pump to the releaser
Size of the pump
Size of the connection between pump and releaser

Since you already have a system setup the easiest change would be a priority circuit. This provides vacuum to the tubing system all the time keeping your vac drop to the desired goal of 0".

A Balance Tank when sized properly will bring your releaser back to the systems vac reading in a second or two.

The closer the pump to the releaser the less friction losses in the transfer of vac speeding the evacuation of the system

A pump with higher CFM reading will evacuate the releaser faster.

The larger the connector of the pump to the releaser the less frictional losses and the more CFMs that can be transferred to the pump from the releaser speeding evacuation.

Personnaly: install a priority circuit to connect the pump to the tubing system with a gate valve so that you can regulate the cfm to the tubing system so that the releaser gets evacuated quickly but when the releaser is dumping the pump is still connected to the tubing system.

Gate valve because it is much more adjustable in fine adjustments than a ball valve.

On my old system I had a 3/4" or 1" line that went to a reservoir that connected to the releaser. The reservoir was just over 2' of vertical 3" pvc as soon as the flapper valve opened the sap would rush into the releaser from gravity force and from the vacuum force to rapidly fill the releaser. The trick to this system was to supply enough vac to keep vacuum on the system and to not suck sap to the moisture trap. The normal setting of the valve for peak production hours was 1/2 a turn open. During nonpeak hours the valve could be open more but it did not change the vac reading on the system so it would be left at the peak flow adjustment.

Sorry for the long explanation but I fell it is better for you to understand all the options and how to use them so that you can change your system with which ever will be the easiest for you to use and achieve success.

Feel free to pm a pic or post a pic of your system and I will suggest you to install a priority circuit. These can usually be added in an hour or less. I added mine while the system was running with only a few seconds of interruption to the vac flow. You can add yours when the lines have frozen at night or in the am before things are running for the day.

Remember that as you have learned from others postings, others will learn from yours...so ask ever question and I will do my best to answer them as quickly as possible but please remember it is sap season and I don't have IT service in the sugar house at this time. Someday I will but not yet. :)

Also, I urge everyone not to judge an artist by his tools but by his finished product. So don't laugh at my system and I will not at yours.
11125
My old system with the vertical reservoir...yes that is duct tape to seal a leak. There is a sap filter in the 3" horizontal pvc chamber.
11124

This is the current releaser setting on top of the same collection tank with the walls painted. Note the 14" 1.5" diameter ladder on the manifold. That sap line runs to the sugar house at 1% grade and has to be lifted into the releaser. The jar is dumped by a recycled milk pump on the bottom and into the bulk tank. The vac pumps are up stairs and connect thru the 3" white pvc line. 3" to get best vac transfer and as additional condensation area that is sloped to drain back to the SS moisture trap bucket. The glass line that is to the left side of the top of the jar goes outside to a dry line manifold. I used the Pyrex glass system over the SS system as it is easier and more entertaining to kids and adults in tour groups. The glass has also taught me a lot of how sap flows and reacts in the system. I never really comprehended sap turbulence until I saw it in the glass manifold system. Amazing to watch one line stop another in the manifold. So I changed the tees from the 3/4" size to the 1.5" size.

Ben

[MT Pockets Producer]

Thanks for the great information. This is a picture of the releaser in the shop. I don't have a picture of it in the bush very handy right now. This is our plan at this point. We will lower the inlet so it will gravity, add the primary circuit and use a larger line between the releaser and pump as suggested ( currently 5/16).The pipe on the side of the releaser is the moisture trap and is 3" by 24 ". Does that offer some balance to the system as well, although not nearly large enough based on the below explanation? Regarding the primary circuit, where should we tap into? Based on a previous post of Breezy's it sounds like one end would go in the manifold between the mains and the check valve? Should the other end go on the line to the pump after the releaser or can it go on the moisture trap ? The manifold we have is 1 1/2 " with three 3/4 inch mains coming in. The unit is is 24 " tall as well so maybe in the off season we should cut that down a little to eliminate some of that unused area so it doesn't require unnecessary. evacuation. The other fixes can be done in a short period of time and in place. We are running a small 2.5 CFM pump so we have a lot to overcome by the sounds of it. In the picture on the far side there is a hose going into the inlet. That has a one inch swing(no spring) valve on it. Thanks again.

JFC.

[MT Pockets Producer]

[ATTACH=CONFIG]11357

Here is a picture of the releaser set up in the bush. I threw the picture of the gauge in there just because we like the number.:D We have hooked the priority circuit to the manifold but it has not made any difference on the vacuum during release. Is it on the correct side of the check valve? This set up,in order, goes releaser, check valve manifold then mains. We originally hooked the valve end into the moisture trap on the side of the unit but have since moved it to the vacuum line between the releaser and the trap. We did this when increasing the size of the vacuum lines and added the balance tank. These improvements have definitely helped with the issue of things hanging up before it releases. Would like to be able to get the priority circuit working though.