How Your Tube-Ice Machine Works; Principle Of Operation - Vogt TUBE-ICE 03TA Service Manual

03TA Service Manual
4-1
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HOW YOUR TUBE-ICE MACHINE WORKS
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4. How Your Tube-Ice Machine Works
Principle of Operation For a detailed description of the functions of each control panel component,
see Section 6. "Clean/Off/Ice", "Start" and "Stop" switches located in the control panel of the
freezing unit control operation of the machine. Automatic operation can be controlled by an optional
ice bin thermostat, which will automatically stop and start the ice maker by the level of the ice in the
storage bin (NOTE: See FIGURE 3-11, "Ice Bin Thermostat Location" for instructions on
installation of the control sensor of the ice bin thermostat(s)). The type ice produced (cylinder or
crushed) is determined by how the machine cutter is set-up (cylinder is standard, crushed or
automatic is optional). The control wiring is arranged so that the unit will stop only upon the
completion of a thawing period whether by action of the "Clean/Off/Ice" switch in the "Off"
position or the ice bin thermostat.
The "Clean/Off/Ice" switch must always be set in the "Ice" position during normal ice-making
operation. It is set in the "Clean" position only when the equipment is to be cleaned as outlined in
the "Cleaning Procedure" (Section 7) and instructions shown on the water tank cover.
If it should become necessary to instantly stop the machine, push the "Stop" button. To restart the
machine, push the "Start" button. The machine will restart in a harvest, to clear out any ice
remaining in the freezer, if stopped during a freeze period.
FIGURES 4-1 & 4-2 illustrate the piping diagram of the refrigerant and water circuits of the Tube-
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Ice machine with numbers for easy reference. Throughout this manual, the numbers you see in
parentheses refer to the numbers in this piping schematic.
The freezer (2) is a shell and tube-type vessel. During the freezing period, water is constantly
recirculated through the vertical tubes of the freezer by a centrifugal pump (6). Make-up water is
maintained by a float valve (12) in the water tank (7). The liquid feed solenoid valve (20),
sometimes referred to as the "A" valve, is open and the thawing gas solenoid valve (18), sometimes
referred to as the "D" valve, is closed.
Refrigerant gas from the top of the freezer (2) passes through the suction accumulator (88), the heat
exchanger (13), and to the compressor (3). Here the cool gas is compressed to a high temperature,
high pressure gas which discharges through the oil separator (14) and into the condenser (15). In the
condenser, heat is removed and the gas is condensed to a high temperature, high-pressure liquid.
The high-pressure liquid goes through the accumulator boil out coil (88) and suction line heat
exchanger (13) where it gives up heat to the suction gas for compressor protection. In addition, this
liquid is subcooled and carried to the receiver (15R). Liquid refrigerant from the receiver flows
through the filter/drier (46), thawing chamber (16), liquid feed solenoid valve ("A" valve) (20) and
thermal expansion valve (17) into the freezer. The "A" solenoid is energized when the machine is in
freeze cycle. The cold liquid refrigerant enters the freezer where it absorbs heat from the circulating
water. Cool gas is pulled out of the freezer at the suction outlet thereby completing the cycle.
The freezing period is completed by action of the freezer pressure switch in the control panel. The
water pump (6) is stopped and solenoid valve "A" (20) is closed. The thawing period then begins.
Solenoid valve "D" (18) is opened, the cutter motor (5M) is started and the harvest (thaw) timer is
activated. Warm gas from the receiver is discharged into the freezer through valve (18), thereby
slightly thawing the outer edge of the ice, which drops on the rotating cutter for sizing. Air-cooled
machines have a solenoid valve (53), sometimes referred to as the "X" valve, in the compressor
3/31/2014