The fat adder enriches feed that requires a high percentage of fat, such as poultry feed, without compromising the compactness of the final product. The cycle starts after sieving the pellet, which makes it homogeneous, well-filled and dry, with a fat percentage ranging from 7 to 11%.
Some time ago, to add fat, you needed a drum machine in the shape of a double half of a cone. The pellet flowed in continuously from one end, sprayed with hot oil and exited from the other end where the screening net was. The product, however, was of poor quality, because the oil did not penetrate into the core of the pellet and, remaining on the surface, turned out to be wet and not homogeneous. To overcome this problem, the product was dried and cooled before packaging.
In latest generation fat adding machines, such as those operated by vacuum, hot fat is introduced while the pellet is being agitated by the shaft blades. At this stage, a vacuum is created inside the device. Gradual opening of the atmospheric pressure valve after an appropriate production cycle and mixing time to obtain a homogeneous product, allows the fat to penetrate directly into the core of the pellet, which results in a dry and excellent quality.
A good compromise between the cost of the product and the cost of the equipment is a device with a continuous cycle of adding cold fat. It uses 2 heated screw feeders and thanks to the very precise flow control it provides the right balance between the amount of fat and the compactness of the pellet.
1. Pellet flows through the hopper;
2. Enters the extraction auger. Its speed is set by an inverter that controls the performance according to the set level on the volume sensors;
3. The flow is continuously weighed by the weighing container. This electronic device measures the force applied to an object (usually a mechanical component) by monitoring an electrical signal modified by the deformation that the force exerts on the component;
4. Grease is sprayed onto the pellets by a spray chamber connected to a 600 liter tank. The process is controlled by a dosing pump and a flow meter that sets the oil addition according to the pellet flow. Fat is mainly made from industrial animal waste (chicken fat);
5. The pellet passes through two screw feeders. The duration of the production cycle is sufficient for the oil to uniformly penetrate into the core of the pellet thanks to the rotation and the blades. heating is achieved by means of electric plates that are in contact with the outer shell of the screws (70-80 °C) of the pipes;
6. The device releases the product ready for packaging
● LOP-F 10: motor 3 kW, feed screw diameter 300 mm, length 10 m. 5.5 kW capacity 10 t/h
● LOP-F 20: motor 3 kW, feed screw diameter 300 mm, length 14 m. 5.5 kW capacity 20 t/h
● LOP-F 10: motor 4 kW, feed screw diameter 350 mm, length 20 m. 7.5 kW capacity 30 t/h
The painted steel dosing system consists of:
● bunker 1.5 m3
● volume sensor: sets the flow according to the set level
● Extraction auger, variable volume with motor with built-in inverter, 3 kW.
Painted steel screw feeder consists of:
● Diameter 300 mm.
● 10 m length for LOP-F model and over 10 t/h capacity
● Predisposition to heat resistance.
● motor 5.5 kW
Heating the screw facilitates the absorption of fat and oil, and the screw itself is kept clean.
For model LOP-F 20, the screw feeder is 14 m long and 300 mm in diameter.
For model LOP-F 30, the screw feeder is 20 m long and 350 mm in diameter.
The liquid dosing system consists of:
● Liquid tank AISI 304, capacity 600l., intended for steam heating
● Valves and nozzles for liquid separation, air injection, post-process cleaning
● Positive displacement pump
● Mass volume sensor with 4-20mA. Signal proportional to product flow
● Ventilated servomotor, 1.5 kW
The spray chamber made of AISI 304 consists of:
● Grease spray nozzles
● Compressed air ports for low pressure liquid spraying 0.5 bar
Electronic control panel for liquid dosing and for system motors.