Typical chocolate conching machines consist of a large jacketed vessel containing a mechanism to ‘tumble’ the ingredients required to make chocolate. This tumbling process can generate considerable heat. If the ingredients are not cooled the reduced friction will cause incomplete mixing. Once mixing is complete it may also be necessary to heat the conch and then cool it again. Because there is a large amount of chocolate in relation to the surface area of the conch, it takes a long time for the chocolate to heat up or cool down.
- Accurate temperature control providing consistent product quality
- Cascade control prevents chocolate from melting when mixing
- 2604 Self-tuning facilities simplify commissioning
- Stops Chocolate solidifying
As a consequence of the long delay in heating and cooling normal single loop temperature controllers will not work satisfactory on this type of system. To solve this problem Eurotherm’s 2604 controller using a cascade control set up is be used. Heating and cooling is controlled by pulsing solenoids. These allow hot and cold water to flow into the conch’s jacket.
Using the cascade PV feedforward option that is available in the 2604 controller it is possible to limit the temperature difference between the water jacket and the chocolate. This is particularly desirable when cooling to ensure that the chocolate close to the wall of the jacket does not solidify while the bulk of the chocolate is still warm.