The vacuum mixer was conceived to integrate liquid ingredients (i.e., oil and melt fat) directrly in the extruded product as soon as it has gone through the drying process.
The liquid absorption is guaranteed on a product with diameter ranging from 2 to 18 mm. with maximum humidity up to 8%.
The percentages of liquid ingredients that can be added to the product range from 8 to 20% and the top amount of achievable vacuum is -20mBar.
Liquid addition process:
Load hopper #1 till it reaches the pre-set weight; once this weight is reached, the bypass deviates towards hopper #2.
The first batch of product is discharged in the mixer by the opening of the hopper’s shutter; at the same time, the mixer’s valve is opened. Once the pre-set weight is reached (and detected by the load binb on the mixer) the shutter closes and immediately afterwards the mixer’s valve shuts as well.
The amount of liquid to be sprayed is weighed and then the liquid is injected in the mixer.
The “vacuum pump” creates the vacuum in the mixer up to the pre-set level. The vacuum is detected by a pressure transducer.
Then the product is mixed for the pre-set time; after that, the air pressure is restored by the opening of valves.
At the end of the process, the discharge door and the discharge valve open up; now the mixer is ready for a second batch.
The length of the process depends on the settings: it may vary from 6 to 10 minutes.
The weight of the batch may vary from 300 to 1500 Kg.