The Automatic Reflector

It is the basic component of the system. The reflector is composed of a motorized electromechanical device on two axes, controlled by a dual processor opto-electronics system, and a reflecting surface of approx. 0.5 mq. It is totally autonomous and does not require any external power source because it feeds itself directly with the light from the sun. Its function is to direct the reflected solar radiation onto the roasting rotor, regardless of the current position of the sun. It is wirelessly connected to the main control unit which checks its status. The number of Reflectors (Heliostats) of the chosen configuration determines the power of the system and therefore the quantity of coffee that can be roasted every hour. Furthermore, the total autonomy of each single reflector guarantees intrinsically very high system reliability, since, even in the event of a single unit malfunction, all the others will continue to operate regularly, thus allowing the system not to be interrupted in production. .

Technical Specifications of the single Reflector:
– 2-axis motorized aiming system
– Autonomous power supply with photovoltaic cell
– Optical aiming accuracy: better than 0.1 degrees
– Dual processor electronic control
– Wireless connection with the Control Unit
– 19 Photoelectric sensors
– Watertight photo-detector container
– Reflective surfaces: 3 mm safety glass
– Reflectivity: 90%
– Aluminum-Magnesium alloy support frame
– Reflective surface area: mq. 0.5
– Maximum equivalent radiant power: 450 W.
– Dimensions: 500 x 500 x 800 mm
– Weight kg. 8

The supporting frame

It is an aluminum-magnesium alloy structure, light and very resistant to corrosion. Allows the assembly of multiple reflectors into a single functional unit. Configurations of 8 Reflectors and 6 Reflectors are provided.

The Control Unit

This is the “brain” of the system. It is a computer to which various sensors are connected that detect the temperature of the coffee beans, voltages and currents of the various parts of the system, the speed and acceleration of the impeller. The control unit controls, using a wireless network, the activation of the reflectors (aiming, standby, suspended, rest). The interface with the system is achieved through a color touchscreen monitor and a voice interface. In addition to the current parameters, the monitor also displays a graph indicating the roasting temperature trend. The control software allows to automatically obtain a perfect and constant roasting even in conditions of climatic variability.

The Configurations

All the configurations foresee an impeller directly controlled by a control unit and a certain number of reflectors installed in groups on load-bearing frames.

The productivity index of a plant is linked to the value of the heliophany which indicates the duration of sunshine in a specific location or area.
For purely illustrative purposes, consider a plant located in Puglia with index 220, we will have the following annual productivity values ​​for 3 types of plant.

With 24 heliostats in 3 groups 18,000 kg
With 32 heliostats in 4 groups 24,000 kg
With 40 heliostats in 5 groups 30,000 kg

(Keep in mind that each locality has its own particular heliophane index determined by the morphological characteristics of its territory: for example in Alto Adige there are areas with a heliophane index higher than 300).

In the economic evaluation of the investment, it should also be considered that the PuroSole system, compared to a traditional roasting plant of equivalent productivity, allows an annual saving of about 60,000 KWh for a production of kg. 30,000 of coffee, thanks to the use of direct solar radiation alone.