Kinazi cassava plant is the factory specializing in cassava processing. It has the following steps:
– Cassava offloading
– Cassava washing and peeling
– Cassava crashing and rasping
– Fermentation and dewatering
– Drying and Packaging
Factory Milling Capacity: It has a capacity of processing 6 tons of fresh cassava roots per hour to produce 2 tons of properly fermented and dried cassava flour per hour. Working 20 hours per day, the factory mill is capable of turns in 120 tons of fresh cassava roots producing 40 tons of flour.
1. Cassava offloading
• The fresh cassava roots are brought directly from garden. The truck parks on the Discharge Platform, which automated by a hydraulic system.
• A truck with a tipping mechanism is offloaded normally by tilting the tipper until the entire load slide to the deposit tank.
• A truck without a tipper is offloaded with the help of a hydraulic-operated discharging platform. When the platform is operated, the truck is inclined until the roots slide into the deposit tank.
2. Delivery to the Roots washer
• The roots are conveyed from the deposit tank to the washer by an Automatic Feeding Thread Conveyor. The screw conveyor turns at an RPM of 3.3 and is operated by a motor and gear speed reducer of 1:430
3. Washing and Peeling
• The cassava roots from the automatic feeding thread conveyor drop in one of the washer ends. The washer arms (figure: 3) with serrated ends work as conveyors and aid in washing and rasping (scratching) continuously by friction of the roots.
• The peels and waste water are drained through the grills at the lower portion of the washer
4. Root Crashing (grating) & Disintegrating (Rasper)
• The clean roots are then delivered to a Roots Crasher with a set of eight knives, by the inspection belt so that they are cut (grated) into small units.
• A Lifting screw conveyor then delivers the grated pieces to the Rasper machine (disintegrator) where the grated units of cassava are raspered (smashed) to make a paste of uniform grain size for later feeding of tanks
• The paste prepared in the Rasper machine is conveyed to the Fermentation tanks (figure 7) by a positive displacement Mono pump.
• Fermentation of the paste is done to reduce Cyanide content in the paste. This lasts for up to 72 hours.
• Valves at the top of the Fermentation tanks are opened depending on which tank is chosen to accommodate the paste.
• The fermentation tanks have an agitating system so that the paste does not become compact.
• The fermented paste is transported to the Press Filter by a Mono pump. The water content of the paste is squeezed out of the paste by a hydraulic and pneumatic operated press filter. The moisture content after pressing is about 40%.
• The water and starch that is squeezed out of the paste is drained to the Sedimentation tanks before being pumped to the Waste Water Lagoons.
• At the end of the pressing process, the filtered mass is dropped into a Mass Box below the press filter when the pneumatic system is released. The mass box has a dismemberer (crumbler) positioned in the middle to disintegrate the mass. In the bottom of the box, there is a screw conveyor that transports the mass to another screw conveyor (feeding to the sieving unit) after a double crumbling unit.
b. Sieving (sifting)
• The Mass Box Output Screw conveyor (1) transports the mass to the double crumbler (2) where the mass is made lose and fed to the vibratory sieve.
• The finer flour is sieved (3) to the lower level and proceeds (4) to the dryer feeding screw conveyor.
• The spikes in the mass that do not go through the sieve are automatically drained to a side and fed to a Return elevator screw (6) and again to the double crumbler (2).
c. Flash drying
• The flash drying system is composed of the following components: (1) Diesel or Peat burner, (2) Heat exchanger, (3) Exhauster EBS-900, (4) Tubing, (5) Crumbler that pulverizes the mass received from the lifting thread conveyor, (6) EBS 500 exhauster that sucks the heat from the furnace into the heat exchanger plates, (7) cyclones that separate the air from the product and (8) rotating valves.
• The warm air from the thermal exchange from the heat exchangers, and the product stemming from the lifting thread enter the dryer pipe with 50% moisture, which is absorbed by the warm air and transported into the cyclones that separate the air from the product.
• The moisture level as the product emerges out of the dryer is about 13%.
• The temperature of the hot air has to be kept between 100 and 80 ◦C.
STORAGE AND BAGGING
The 60T Classifier (1) is fixed on the top of a platform (2). The sieve used in the classifier is a 3.0 hole mesh. Its function is to separate the dry flour from the cobs. The dry flour feeds automatically the bagging machines (3). The cobs are transported through a pipe (4) by gravity to the hammer mill.
In case of using the 1 and 5 kg packing machines, the bagging machines shall be turned off and a thread conveyor embedded on a lung box of the bagging machine transports the flour to another tilted thread conveyor which at its end distributes the flour by gravity into the two packing machines.