(1) Skin mill system. 4 ~ 7 grinding and screening procedures. 1 ~ 3 procedures for crushing wheat, extraction with heart and bran mic heart (called slag), sent to clear powder system and slag grinding system respectively. Left behind with endosperm bran to 2 ~ 4 procedures of grinding and sieving, scrape the bran on the rest of the endosperm. Coarse bran as by-products, wheat heart and coarse powder sent to the posterior heart mill system.

(2) Clear powder system (purification system). Using the combination of wind, sieve powder clear machine will separate wheat heart and slightly bran mic (residue), and sucked out part of bran crumbs.

 

(3) Slag grinding system. This is 1 to 3 procedures. It will grind the wheat heart with bran from skin mill and powder clear system, scrape off the bran wheat heart send to wheat heart grinding system, and wheat heart with bran still back into the clear powder system.

 

 

(4) Wheat heart grinding system. This is five to eight procedures. Grinding the wheat heart and coarse powder into flour which get from clear powder system, skin grinding system and slag grinding system, and remove fine bran. Four systems of flour focus on the test sieve, sieve to finished product of flour.


The above powder flow system called “long powder road”, can produce high quality flour, but the yield is low, power consumption is higher. Some flour mill plant use only skin grinding system and wheat heart grinding system of road called "short powder road". This type is large flow of unit equipment production, low power consumption and cost, but the poor quality of flour. Road with long and short powder each has characteristics, the current Chinese wheat flour mill used more joint production, namely, special powder and general powder joint production. World powder development trend is to use long road production high quality flour, and extract the germ.