How An Ice Cream Roll Machine Works
We are often asked how a rolled ice cream machine works. In this article, we take a look at how different types of rolled ice cream machines work. Click the photo below for a larger view of the ice cream roll machine refrigeration schematics.
An ice cream roll machine can be constructed several different ways. The cheapest machines on the market use a single simple refrigeration loop. A compressor outputs a high-pressure high-temperature refrigerant vapor. This hot refrigerant vapor goes through the condenser/fan unit which removes the heat from the gas and transforms it to a hot liquid refrigerant. The liquid refrigerant then goes through a capillary tube which drops the pressure and temperature of the liquid. This low temp liquid refrigerant then enters the cold pan's cooling coils, where heat is absorbed by the refrigerant travelling through the tubes. This is what cools the ice cream pan's surface. As the refrigerant warms, it changes back to a low-temperature low-pressure vapor. This vapor is then sucked back into the compressor where it is again compressed back to a high-pressure high-temperature vapor, starting the entire cycle over again.
With the cheap pans on the market, the temperature is regulated in these systems simply by turning the compressor on and off. This poses several problems. First, turning the compressor on and off frequently is not good for it. This will lead to an early failure of your compressor. Second, this type of regulation doesn't allow the pan surface temperature to equalize. The middle of the pan might get cold but the outer edges are not likely to reach the desired temperature. The longer the compressor runs the more the temperature differential across the pan will lessen. But, there is a better way.
Adding a refrigeration solenoid between the compressor output and input provides another method for regulating temperature. When this solenoid opens a portion of the hot vapor coming from the compressor is bypassed around the normal refrigeration loop and is fed directly back to the compressor, effectively reducing the refrigeration capacity of the circuit. This allows the pan surface to gradually warm up during this time. While this method is better than the previous one mentioned, it still has one issue. When the bypass solenoid is open the hot gas can travel backwards through the pan's coils. The effect of this is the ends of the pan warm significantly. The more expensive Kolice brand units use this type of regulation.
The Arctic Griddle series of rolled ice cream pans are the only one's on the market to have solved this last challenge. A check valve is included in the output of the pan coils to prevent this reverse hot gas flow. While this adds cost to the construction of our units, our pan tops have the most even and stable temperature control of any rolled ice cream machine on the market.
Defrost for almost all machines on the market is done through a hot gas process. A solenoid is connected between the output of the compressor and the pan's coil input. When this solenoid opens, the hot gas rushes through the coils and warms the pan significantly.
When a cheap rolled ice cream machine fails it is almost always the result of a bad solenoid or relay that controls the solenoid. Therefore, just having these components is not enough to make a machine good. These particular components must be of high quality and reliability or they will actually lead to more problems down the road.
If you have any more questions about how a rolled/fried ice cream machine works please feel free to send us your questions.