 |
Introduction
The Auper flow meter was originally design specifically
to be used in draft beer. Three years of R&D
were necessary to originally design this flow meter
which has remained unchanged (and copied) since
its release on the market in 1985. Auper was the
first company to manufacture such a flow meter in
North America. Tens of thousands are in use all
over the world in all kinds of draft beer dispensers.
It is used to monitor other products too, such as
soft drink, juice, coffee, oil, water etc... We
use standard Hex nut, washers and draft beer tailpieces
to adapt to all plastic beverage tubing. The internal
diameter of the tubing may vary from 3/16" (4.7mm)
to 1/2" (13 mm). Tailpieces are available in chrome
plated brass or stainless steel. |
Operation
Liquid flowing into the flow meter (turbine)
causes the propeller located inside the flow meter to
spin. The internal diameter of the turbine and the design
of the passageway allows a liquid to circulate normally,
without cavitations or blockage. A flow meter is selected
according to its typical flow rate specifications. At
equal pressure, a liquid with a low viscosity (beer, water)
flows more easily and at a faster rate within the same
line than a thick viscose liquid like syrup. We
are never concerned with the type of liquid we are measuring
but by the speed at which it is dispensed. The Auper flow
meter is made of Delrin for its durability, its low friction
properties (close to Teflon) and extremely low absorption.
It is covered with rubber to protect it from moisture
and water. The flow meter does not require any power from
the electronics it is connected too. An accidental short-circuit
would not damage it. The signal generated by this flow
meter is totally independent from the type of product
it is measuring; viscosity or dark products would not
block the passage of an infra-red beam for instance.
The Auper flow meter model 50-316 has an operating curve which was designed for
standard draft beer dispensers. This model operates very
well on beer lines with an internal diameter between 3/16"
(4.76mm) and 3/8" (9.25mm) with an average flow rate between
1 and 2.5 oz/sec (1.5 and 4 l/min). Some
products such as the Guinness beer or carbonated water
are often running at slower speed and will require a model
with a slower typical flow rate (50-018). Ask you Auper
representative for guidance before you order.
|
Model
|
Application
|
Pulse/oz
|
ml/pulse
|
Typical
flow rate
|
|
50-018
|
Guinness/Soft
drink/Soda |
30 |
1 |
1
Oz/sec |
30
ml/sec |
|
50-316
|
Draft
beer/Wine/Soda |
15 |
2 |
2
Oz/sec |
60
ml/sec |
|
50-332
|
Alcohol/Syrups |
45 |
0.6 |
<
0.5 Oz/sec |
<
15 ml/sec |
|
50-114
|
Fast
flow applications |
7 |
4.25 |
4
Oz/sec |
120
ml/min |
Installation
The flow meters are usually mounted in the storage room
above the keg, on top of the wall bracket. It is inserted
in the rigid tubing and secured to the wall using a
plastic bracket when necessary. If FOB detectors (also
called empty keg detectors) are used, the flow meter
should be installed after this device. The FOB will
prevent the flow meter from ever being in contact with
foam or air rushing up the line.Each product line has
to have a flow meter. Each flow meter is wired out of
the storage room to either one of the Auper electronic
controllers. Each flow meter is identified by line number,
brand name and destination.
Beer Line Cleaning
The norms for beer line cleaning will vary from one
country to another. Most beer line cleaners use a caustic
solution (bleach) to clean and disinfect the lines and
then rinse using soft water. The turbine should remain
connected to the line in order to benefit from the line
cleaning. When ever lines are cleaned, the meters should
be read before and after or the system could be disabled
by the manager. In certain countries, norms require
that a sponge be used during the procedure. The turbine
would have to be removed from the line since it will
block the passage to the sponge or the sponge would
block the flow meter. The company responsible for the
line cleaning must be warned that flow meters have been
installed in the beer lines and you must request that
they use chemicals instead of sponges.
Beer line cleaning should take place at least every
4 to 6 weeks.
Trouble shooting
foamy draft beer
Draught beer is a sensitive product which requires a
certain number of parameters to be just right :Temperature,
pressure, propellant and good beer system design.
The Auper flow meter (turbine) is guaranteed not to
make beer foam. However, the installation of flow meters
into your beer lines will not solve the foaming problems.
It would only tell you how much is wasted. Before you
proceed with the installation of the flow meters, take
a good look at the dispenser itself and ask a few questions.
Test the system in the morning before the bartenders
start using it.
1. Does the serving temperature correspond to the brewers
norms ?
- North America: 38F(3.3C)
& 42 F(5.5C)
- Europe: 43F(6C) & 48F(9C)
Pour a glass and insert a thermometer immediately in the
freshly poured beer. If the temperature in the glass is
outside these norms, it is quite possible that your refrigeration
system is defective or needs adjustment. Too high a temperature
will increase the risk of excessive foaming. If too cold,
the beer is not foamy enough and bartenders usually serve
more in each glass. In either case, you should be concerned
that the pour cost will probably be too high.
2. Is the flow rate between 2.5 and 3.5 l/min (Aprox:
2 oz/sec) ?
If the flow rate is too slow, it is probably due
to a lack of pressure in the system. The C02 gas can separate
from the beer while in the line causing the beer to foam
at the tap. The color of the beer will change a few seconds
after the tap is opened, passing from a clear and golden
color to white. A gas leak will have the same effects.
3. Check the propellant ! Is the beer flat or over carbonated
?
Any beer system with a distance between the kegs and the
faucet greater than 10 feet (3 meters) should be pressurized
using a mixture of air or nitrogen (70 %) and CO2 (30
%). Straight CO2 can be used for direct draw systems and
very short runs (less than 10 feet or 3 M). Clean straight
air can be used if the sales volume per day is very high.
Otherwise, it will either contaminate the beer (think
of where the air is pumped from) or it will make the beer
flat. The wrong choice of propellant will either make
the beer foam, make it flat or change the taste. In either
case you will be wasting product thus increasing your
pour cost . Get a qualified technician to look at the
problem !
Non-refrigerated kegs (Europe)
Temperature is one of the elements that will
affect draft beer along with pressure, the type of gas,
the line design and the product itself. When kegs are
stored in a non-refrigerated room, an increase in the
store room temperature will have an effect on the way
the product pours at the faucet. The higher the storage
temperature is, the more gas pressure will be required
to dispense the beer properly. When kegs are kept in a
cooler, the external temperature will not have an effect
on the draft beer since everything is under a controlled
environment. With this type of installation, pressure
settings are often kept to a minimum. The smallest change
in temperature will have an effect and may cause foaming.
Before you proceed with the installation of the flow meter,
check if you can dispense draft beer for 15 seconds with
the beer retaining its golden color when coming out of
the faucet. If after a moment, it turns white, the pressure
is too low. Inserting a flow meter will only make things
worse. Increase the pressure by 2 PSI (14 KPa) and try
again. Repeat this procedure until you can pour beer properly
for at least 15 seconds. When inserting a flow meter in
the beer line, the additional friction may have to be
compensated by increasing the pressure settings. Once
the flow meter is in place, do the same test and follow
the same procedure.
Soft drink and Juice
Pre-Mix
Whether it is wine, juice, or soft drink, if
it's ready to serve it’s Pre-Mix. As with draught beer,
one flow meter per line will be necessary.
Post-Mix
For Post-Mix dispensers you have the choice of measuring
the syrups or the carbonated water. If you are only interested
in the total amount of soft drink dispensed , you will
only need one flow meter connected to the carbonated water
line (soda).
1. Measuring carbonated water
The ratio of the mixture (or “Brix”) is usually the same
or very close for all the syrups (5:1). By installing
the flow meter in the carbonated water (soda) line you
will register the total amount of soft drink served through
the dispenser. Since one carbonator unit can feed multiple
dispensers, it is possible to install the flow meter closer
to the carbonator just before the line splits to each
dispenser, to monitor the total soft drink dispensed .
If you want to monitor each dispenser separately, then
the one flow meter per dispenser is installed, after the
split, closer to the dispenser.
2. Measuring syrups.
If you want to know the quantity of each flavor served,
you will need to install a turbine on each of the syrup
lines. For this application it is necessary to use
the turbine with model number 50-032 (slower flow rate).
|
