10 March 2022 / RICK UZUBELL / Comments Off on How Do Glycol Beer Systems Work?
How do glycol beer systems work? Learn how the equipment works and why glycol systems are the most popular choice today.
HOW GLYCOL BEER SYSTEMS WORK
Glycol draft beer systems operate through a process which is accomplished through three components:
Power-pack
Trunk line
Draft beer tower
POWER PACK
The power pack is a commercial refrigeration unit. It is the heart of the glycol system. The power pack is rather compact, as seen in the photo below. Don’t let this small package fool you. An individual power pack can house one-three pumps and motors. A single, properly-sized power pack can manage up to three trunk lines, each up to 750’ in length, each capable of handling up to 24 beer products. In this plan, we’re showing the possibilities for three different opportunities for trunk lines in this particular building.
GLYCOL DRAFT BEER SYSTEM POWER PACK
TRUNKLINE
A cross section of an 8-product glycol trunkline is shown in the photo below:
This shows eight narrow-diameter product lines around the perimeter, sandwiched around a pair of glycol refrigeration lines.
One glycol line is outbound (extending from the power pack to the beer tower).
The other glycol line returns from the beer tower back to the power pack.
Each product line of the trunk line is connected to a unique draft beer keg in the walk-in cooler.
The kegs are connected to CO2 and nitrogen cylinders through a series of gas blenders and pressure regulators.
More simply, the trunkline provides a conduit for the beer product lines, connecting kegs of beer in the walk-in cooler to each respective faucet of the draft beer tower. At the core are sealed refrigerant lines which extend from the power pack to the tower in a continuous loop.
PHOTO OF DUAL-SERVICE INVERTED GLYCOL BEER TOWER
HOW TO INSTALL GLYCOL TRUNKLINES
Glycol trunklines are typically installed overhead or under-slab. When installed overhead, the trunklines are commonly housed in black iron pipe, as shown in the photo below. When installed under slab, each trunkline is individually housed in 6″ Schedule 40 PVC tubing.
GLYCOL DRAFT BEER SYSTEM WITH OVERHEAD TRUNKLINE
PLAN OF GLYCOL TRUNKLINES INSTALLED UNDER SLAB
HOW THE TEMPERATURE OF THE DRAFT BEER IS MAINTAINED
As each beer product travels from the keg to the draft beer tower its temperature rises temporarily. This is due to the pressure of the gas that’s pushing it and the resulting drag caused by the plastic product lines that resist. By virtue of the principles of thermodynamics, the refrigerant lines dissipate these temporary temperature gains. The beer products are ultimately delivered at 38 F by the time they get to each respective faucet.
HOW THE GLYCOL BEER TOWER WORKS
As the draft beer travels from the walk-in cooler, I discussed the general concept of temperature maintenance. However, as approaches the tower, the job still isn’t over. The beer can still experience temperature gain over the final segment of its journey. According to industry leader Micro Matic, a lot could still go awry inside the beer tower. Micro Matic towers are designed with a bit of additional engineering so the beer is dispensed at 38 F at the end of each faucet.
Inside the tower, behind each beer faucet is a stainless steel shank, depicted in the above sketch as black circles.
Surrounding each shank is a copper assembly known as the "cold block"
The inbound glycol refrigerant line (shown in blue) enters the beer tower through a copper line that travels vertically inside the tower
The refrigerant travels in a loop and returns to the power pack.
Along its return, the copper loop contacts the shank of each faucet and also branches into each respective faucet.
This branch is known as the "cold block."
The cold block controls the temperature of each beer product to the end of each faucet.
THE GLYCOL IS ALWAYS WORKING
Upon leaving the tower, the return-side of the glycol loop returns to the power pack so the refrigeration cycle can be repeated. Even on its way back to the power pack, the return leg of the glycol line still helps to stabilize the temperature of the beer products on their way to the tower.
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