The potato starch industry separates the components of the fresh potato: potato starch, protein, cellulose envelope, soluble fractions. For how to extract potato starch, the potatoes are crushed; the potato starch  are released from the destroyed cells. The starch is then washed out ,refining and dried to potato starch powder.

Potato starch extraction plant

How to extract potato starch from fresh potato ?

The extraxtion process of how to extract potato starch are as below:

(1) Raw material receiving unit:

The potato is carried besides the storage pool after weighing. Firstly, it goes through the vibration sieve for removing the stones and sand. Then the pre-cleaned potato falls on the conveyer and enters into the de-stone and washing process of how to extract potato starch.

(2) De-stone and washing unit:

Potato is transferred into the destone machine to be cleaned by washing conveyor. The small sand and stone go through the rotary screen then meet with bigger size stone which was stopped and sent back to the entrance of de-stone machine. Most of sand and stone are removed out of de-stone machine. The potato then goes into rotary cleaning machine for further removing of dirt and broken chips for how to extract potato starch. Cleaned potato falls into a wahing conveying  equipped with nozzles for washing the surface of potato. Workers can manually take out the rotten potatos, wooden and plastic items. 

DOING rasper for potato crushing

(3) Milling unit:

The milling unit is the most important step for how to extract potato starch. The feeding screw pumped the clean potato into rasping machine. Highly-efficient milling machine will release the starch in potato at most.

(4) Centrifugal extracting unit:

The mixture is transferred to the 3 stage centrifugal sieves, each sieve works with a fiber pump and a defoam pump. The mixture enters into each sieve to separate residue and starch. After 3 stages continuous washing and separation, the filtrate is sent to desanding unit, and the residue is sent to the residue dewatering unit.

(5) Potato residue dewatering unit:

The potato residue will be pumped to the centrifugal sieve for dewatering, the centrifugal sieve works like the extraction sieve for how to extract potato starch. Then the screw conveyor discharges the residue out of the process, and the water will go back to the process water system.

Potato starch extract used main machines

(6) De-sanding cyclone unit:

After centrifugal extracting, the starch milk is transferred to de-sanding cyclone by fiber pump. The hydro-cyclone for how to extract potato starch divide the milk into two parts: the light part which contains the mixture of starch and protein will go out from top of the cyclone, and the heavy part which contains the sand will be discharged out of the system. After desanding ,the material is sent to concentration and refining unit.

(7) Concentration and refining unit

The starch milk from centrifugal sieve goes into the 16 stages of refining hydro-cyclone, and fresh water comes into the cyclone from the end of the potato starch processing machine for how to extract potato starch. Firstly, starch milk is pumped into 3 stages of concentration unit to remove the water, then the condensed starch milk enter the next 13 stages of washing unit, and the overflow enters into another 2 stages of recycle unit to recycle starch. Most of the effluent with fiber is discharged out of the process, and a little part goes back to the process water system. Finally, the condensed starch slurry is pumped into the starch slurry storage tank.

One of our potato starch extraction plant project

(8) Vacuum dewatering unit:

The starch slurry is pumped into inlet tank of vacuum filter machine for dewatering process of how to extract potato starch. Then the vacuum rotary drum will adsorb the starch on the drum surface and the filtrate is transferred out of the system by filtrate pump. The filter cake on the drum will be peeled off by peeler and then transferred to the air dryer by screw conveyor.

(9) Air drying unit:

After dewatering process for how to extract potato starch, the air dryer will dry the starch to the required moisture of the commercial starch. Then starch goes into the screw conveyor.

(10) Sieving and storage unit: 

The starch is transferred into the vibration sieve by screw conveyor, and the sieve is used to separate the coarse and fine starch particle. Then the fine starch goes into starch tank for temporary storage.

(11) Weighing and package unit:

After seiving process of how to extract potato starch, the fine starch goes to the auto-packager, and will be packed into 25 kg/bag.