Short to medium length glycol system design, Update to DBG post a while back
Jeff Stanley
of packing lines.
After experimenting a bit in the large walk-in cooler at our warehouse,
I decided to build a few systems using 1/4 ID tubbing.
In my experimental systems, I routed 100' of each: 3/8, 5/16, and
1/4"ID barrier poly 100' including three bends and a rise and fall of
about 10'. I equalized the restriction so each line had about 35pounds
of restriction (by adding appropriate 3/16 hose as a choker, the line
with 1/4 poly had no restriction added). The systems were very basic.
Poly hose connected to the coupler at one end and the shank, or
choker-then-shank, at the other. Used 30psig of N2(@1200ft over sea
level elevation)to push the beer. I poured Coors Light through them at
36degrees. The beer may have been slightly over its 2.8 vol brewery
CO2 level 'cause it was removed from a keg box set at 16psigafter being
on line for two days. Keg was about half full and was 10 days from
expiring (35 days after packaging).
It took about 30oz to pack the 1/4id line. 60 to pack the 5/16id line,
and 100 to pack the 3/8id line. None of the experimental systems were
nearly as bad as some 3/8 systems I have encountered in the market
which commonly waste several gallons to pack on somewhat shorter
systems. Different restriction methods perhaps?
I then flushed each line with hot (130degreeF) water, then packed with
beer again. The hot water didnt make much difference in packing the
lines. Seems beer (at least in mix gas systems) cools the system
enough after a cleaning to only make a slight difference in beer waste.
1/4 id system actually had less waste when pushing out hot water than
when packing an empty line.
This gave me enough confidence to build systems using 1/4id barrier
trunk lines in the marketplace.
I have assembled four of them now. All are between 55 and 60ft long.
All include some used/rebuilt parts. All share a very basic design.
1. Mcdantim Trumix 100 blender
2. Gas distributor manifold
3. Coupler
4. 5/16id vinyl jumper made with brass tailpieces
5. Stainless steel wall bracket
6. 1/4id trunk line (one of the trunk lines was 12 product and I only
used two coolant lines, which worked fine because the smaller outside
diameter of the beer line allowed contact of each line with a 3/8id
coolant line. This means that the coolant is out of the power pack
half as long as when using 4 coolant lines like all other 12 product
trunks use. This trunk was built with 1" thick insulation rather than
3/4 simply because I was second guessing myself a bit) Trunks were 1/4
barrier poly wrapped with foil moisture tape, 3/4" thick insulation,
then vinyl tape as an outer moisture barrier.
7. Tower. One system used a micromatic coolrite. The other three
were hand-built: I took forced air towers and wrapped them for glycol
by hand.
None of these systems waste more than 1/2 pitcher to pack lines. As an
added bonus, they seem to have a cold plate effect on the beer more so
than a normal trunk line (they actually chill the beer a bit as it
makes its way through the line.
I quit using secondary regulators a while ago when using mix-gas, but
that is a different discussion. Fob-stops are pointless without the
waste issues of 3/8id trunks. Therefore these systems were CHEAP to
build! From my experience retailers dont place a value on the system
based on low long the parts list is, they will pay for performance!
Why not build em like this, have them work better and just make more
margin on installs?
I am guessing the 1/4id lines clean better because the caustic moves
much faster through the hose. Comments?
In systems over about 60ft, a 1/4id trunk would require beer pumps (I
have heard that operating pressures over 30psi on mix gas systems allow
a noticable amount of N2 into solution, just going by the expert
grapevine out there). Beer pumps could be used to push beyond 60ft.
I personally will not eliminate the mix gas in the pump systems because
I like simple systems where all beers operate at same pressure and no
one goofs with operating pressures but me. I also like eliminating
overcarbonating which happens to some extent in every 100% CO2 system.
Balancing systems with 100% CO2 is a skill most techs dont have. Most
100% CO2 systems, even those which draw clear, overcarbonate somewhat.
Only difficult thing about designing these systems is determining your
operating pressure before-hand and ordering the correct gas blend. I
dont see this as difficult at all and you could screw it up a bit and
still end up with better beer and less waste than what keeps popping up
in my market.