The raw mixture comes into the refining machine via a hopper and is refined as a result of the crushing action of five parallel rollers, which are arranged vertically, one above the other. Each roller is located at a certain distance from the next one, to accommodate a defined quantity of the raw mixture. As the rollers rotate, they gain speed, the speed increasing from the first through to the fifth upper roller, which may achieve a speed of 400 rpm. The rotational movement transports the product between the five rollers as if it were a film. As it passes through the rollers the mass is dried and ground to a fineness of 15-30 μm.

The HFE-518 is capable of processing 1000- 1200 kg of bulk chocolate per hour. Pressure, speed and temperatures can be controlled and programmed by means of an electronic control via a remote monitoring PC.

The refining machine can be fitted with a patented independent (closed loop) control system and these control devices ensure that it is always in a position to produce a consistent finished product. Should the characteristics of the raw mixture deviate from the specifications during processing, the control system will automatically adjust the refining machine settings until the quality parameters specified have been re-established. This means that a high standard of quality is always guaranteed.

High-performance pneumatics
The machine is fully equipped with pneumatic components from Bosch Rexroth Corp. Special emphasis is placed on the pressure regulating system in the pneumatics circuit, which is fitted with Series ED05 electropneumatic pressure regulating valves. These are known for their high dynamic performance, reliability based on field testing, and high throughput capacity of 800 lpm.

High performance is not the only concern in food procession — compact sizes are also in demand, due to the often confined spaces in designs. “The reason we have opted for the Series HF03 valve units is to enable us to meet requirements in relation to quality and construction,” explains Piero Facchini from Carle & Montanari’s technical department.

The valves in this series feature compact size, low maintenance, plugin construction, and low energy consumption. In addition, the company has been able to considerably reduce the number of valves needed in the machine by comparison to earlier series.

“The Rexroth engineers were there right from the start. They did not just supply the components, they also provided us with support in other technical respects”, says Facchini.