The fat addition machine enriches the feeds that need a high percentage of fat, such as poultry feed, without injuring the compactness of the final product. The cycle begins after the sieving of the pellet that makes it homogeneous, well filled and dry with a fat percentage ranging from 7 to 11%.
A while ago, the fat addition needed a drum machine shaped like a double half cone. The pellet flowed in continuously from one end, was sprayed with hot oil and got out from the other end where there was a sifting net. The product, however, had a poor quality because the oil did not penetrate to the core of the pellet and, remaining on the surface, made a wet and not homogeneous product. To deal with this problem the product could be dried and cooled before packaging.
In the last generation fat addition machines, such as those working on vacuum, the hot fat is injected while the pellet is being mixed by a paddled shaft. At this point the vacuum is made inside the machine. The gradual opening of the atmosphere pressure valve, after an adequate throughput and mixing time to obtain an homogeneous product, allows the fat to penetrate straight into the core of the pellet, which will be dry and of excellent quality.
A good compromise between cost of the product and cost of the equipment is the continuous cycle cold fat addition machine. It uses 2 heated screw feeders and hot oil and thanks to a highly accurate flow meter allows the right equilibrium between amount of fat and pellet compactness.
1. The pellet flows in through a hopper;
2. Goes into an extraction screw. Its speed is set by an inverter that controls the capacity according to the level set on the capacity probe;
3. The flow is constantly weighed by a weighing bin. This electronic device measures the force applied to an object (usually a mechanic component) through the monitoring of an electric signal modified by the deformation that the force induces on the component;
4. The fat is sprayed on the pellet by a spraying chamber connected to a 600L tank. The process is controlled by a dosing pump and a flow meter that sets the oil addition according to the pellet flow. The fat is mainly made of animal industrial waste (chicken fat);
5. The pellet goes through two screw feeders. The throughput time will be long enough for the oil to penetrate into the core of the pellet homogeneously, thanks to the rotation and the paddles. The heating is achieved by the use of steam, which circulates in a net of pipes external to the frame of the screw (70-80 °C);
6. The machine releases the product, ready for packaging.
The available models are:
● LOP-F 10 : Motor 3 kw, screw feeder diameter 300 mm. length 10 m. 5.5 kw capacity 10 T/h
● LOP-F 20 : Motor 3 kw, screw feeder diameter 300 mm. length 14 m. 5.5 kw capacity 20 T/h
● LOP-F 10 : Motor 4 kw, screw feeder diameter 350 mm. length 20 m. 7.5 kw capacity 30 T/h
- Dosing system in painted steel composed by:
● 1,5 m3 hopper
● Capacity probe: sets the flow according to the pre-set level
● Extraction screw, variable capacity with inverter integrated gear motor, 3 kW.
- Screw feeder in painted steel composed by:
● Diameter 300 mm.
● Length 10 m. for the model LOP-F and capacity over 10 T/h
● Predisposition for heating by a net of pipes where the steam flows at 1.5/2 bar
● Condense collector
● Isolation by stone wood packed in a shaped zinc metal sheet
● 5.5 kW motor
Heating the screw will facilitate fat and oil absorption and the screw itself will be kept clean
For the model LOP-F 20 the length of the screw feeder is 14 m. and the diameter is 300 mm.
For the model LOP-F 30 the length of the screw feeder is 20 m. and the diameter is 350 mm.
- Liquid dosing system composed by:
● AISI 304 liquid tank, capacity 600L., predisposed for steam heating
● Valves and nozzles for liquid interception, air injection, post-process cleaning
● Volumetric pump
● Mass capacity detector with 4-20 MA. The signal is proportioned to to the flow of product
● Ventilated servomotor, 1.5 kW
- Spraying chamber made of AISI 304 and composed by:
● Fat spraying nozzles
● Holes for compress air to nebulize the liquids with low pressure 0.5 bar
Electronic control panel for the dosing of the liquid and for the motors of the system.