Convection Tunel Dryer STKw is designed for drying vegetables (eg garlic, pepper, carrot, beetroot, potato), fruit (eg apple, pear, strawberry, raspberry, plum), granules, mushrooms and herbs (drying hemp).

It is a one-door or two-door dryer equipped with a minimum of 3 drying trolleys.

The dryer is supplied by electric, gas, oil or pellet heater.

The drying process is based on bringing the heated air above/below each drying tray through diffusers placed in the walls of the chamber. The direction of the air flow is changed cyclically. The dryer works in batch and continuous mode. *

Drying of the material takes place in a drying chamber on drying trolleys arranged in series on the track. The drying process consists in alternating supply of heated air under each drying tray by diffusers placed in the side walls of the drying chamber. The processed air is discharged to the outside of the chamber through the outlet duct.


* for more information see “CAPACITY” section

CAPACITY

Automation includes:

  • Automatic control
  • Measurement of process air temperature
  • Process air temperature regulation
  • Adjusting the direction of the process airflow
  • Adjustment of the frequency of changes in the process air direction
  • Regulation of the process airflow
  • Temperature measurement of material on any tray

Capacity depends on:

  • – type of material (fruits – apples, pears, plums, raspberries, strawberries, gooseberries, vegetables – carrots, beets, potatoes, peppers, cucumbers, garlic, herbs, mushrooms and nuts);
  • – technology applied, including, among others: loading weight, set drying temperature (variable during the full cycle), air flow rate, material disintegration level, expected quality of the dried product, etc.

Approximation is that the installed 40 kW can theoretically dissipate a maximum of 80 kg water h.

In addition, when dealing with a delicate material, it should be known that the exposure of this material to too high – temperature and intense air flow can result in a very low-quality of dired prodyct. In addition, drying process is not linear, which means that depending on the stage of the process, the amount of water discharged will change.

We offer our customers driers equipped with an additional reserve of thermal power, which is necessary at the beginning of the drying process in order to warm up as quick as possible, and thus, to induce quick initiation of evaporation. The installed power must be adequate to the needs of the customer, who may want to dry, eg plum (which has an input load of about 20 kg/m2), but also apple chips (whose input load is about 2 kg/m2).

The evaporation rate depends mainly on the degree of material disintegration, i.e. the ratio of the evaporation surface to the volume, e.g. apple in slices of 7 mm thickness, dried for 7-8 hours, apple in 2 mm slices, dried in 2-3 hours.