be guided back to the feed tank with a flexible tube. This allows the product to
be re-circulated.
6. Press the feed pump ON button on the control panel, and use the UP/DOWN
buttons to set a pump speed of approximately 40%. Water should then flow
from the feed tank, through the heat exchanger, and back into the feed tank
through the flexible tube.
7. Slowly turn the back-pressure valve adjusting screw clockwise in order to
build up a pressure in the heat exchanger. This can be observed on the digital
display (A). Keep on increasing the pressure gradually until 4.0 bar is
indicated.
Do not allow the pressure to fall below 4.0 bar as this pressure is required to
prevent boiling in the heat exchanger.
Note: The system is designed for pressures to a maximum of 10 bar. These
higher pressures are only used when carbonated beverages are being
processed in order to keep the gas in solution.
8. Measure the product throughput with a measuring cylinder and stopwatch.
Adjust the feed pump frequency and the back pressure valve until a
throughput of approximately 10L/hr (167ml/min) is achieved at an indicated
pressure of greater than 4 bar.
9. Press the HW Circulator ‘ON’ button on the control panel.
Water will be circulated by the gear pump through the heating section of the
heat exchanger and returned back into the reservoir. The electrical heating
element in the reservoir will begin to heat the water. The temperature displays
for the hot water and the holding tube temperature should begin to rise (the hot
water temperature should always be the hotter). The temperature display on
the temperature controller should be close to the displayed holding tube
temperature.
(Note: An offset can be eliminated by programming a non-zero value in the
OFFSET function of the controller, see page 41.)
The indicated temperature of the product outlet should also rise.
10. Open the valve of the cooling water flowmeter (20) fully to give a flow rate of
at least 3.0 l/min. The product outlet temperature should now start to decrease.
11. When the set point of the circulator controller is approached the power will be
automatically modulated to the heater in order to maintain the temperature at
(T1) constant.
32
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