TECHNICAL PROCESS of obtaining activated carbon
The raw materials for activation can be charcoal of any species including wood of hard and soft wood species. Shells of various nuts (coconut, walnuts, hazelnuts, cashews, cedar, etc.) are especially good for activation. The higher the density of the raw materials for activation, the better the properties of activated carbon will be manifested.
Whatever the raw material, it must first be carbonized to produce a high carbon charcoal.
- Charcoal raw materials, is divided into fractions of a certain size: 5-15 mm, 0-5 mm and 15-40 mm, and is loaded into a hopper-drive with built-in gateway feeder. The fraction of raw materials will correspond to various brands of activated carbon.
- From the raw material storage hopper, the charcoal is metered through a lock gate onto the conveyor belt.
- From the conveyor belt, the raw material is loaded into the hopper-feeder to a set level. This level is monitored by built-in sensors which give the command to turn on or off the motors supplying the charcoal for activation.
- From the hopper-feeder, strictly metered amounts of raw materials are fed into the steam activation oven using a screw auger.
- Simultaneously with the feedstock, steam superheated to a high temperature is supplied to the activation oven.
- The axis of the activation tube is angled slightly off the horizontal. A motor and gearbox drive the rotation of the auger, which moves the charcoal undergoing activation through the oven from the point of loading to the place of discharge.
- The rotation of the activation tube ensures the charcoal is thoroughly agitated. This chaotic movement efficiently exposes all the material to the superheated steam.
- The walls of the activation tube are preheated in the range 800o to 1000° C, depending on the selected activation mode, before loading the raw materials.
- Raw materials progressively move along the inner body of the tube from the input to the output.
- The residence time of the raw materials in the activation zone is determined by the slope and rotational speed of the activation tube.
- At the outlet of the activation tube, the carbon which has been treated with superheated steam enters the screw cooler. There the activated carbon now obtained is cooled and stabilized using steam.
- Then the freshly activated carbon enters the separator. This separates the various size fractions of activated carbon, and passes the separated material into storage bins.
- As activated carbon arrives from the separator, silos are filled — these storage tanks are connected by feeders to the filling machine.
Finally comes the packaging of fresh, activated carbon in the containers specified by the customer.