Using DA 7300 & DA 7440 in Wet Corn Milling Processes

Juneng Golden Corn Co., Ltd processes 1.3 M tonnes of corn annually in two locations in China. The end products include 850 000 tonnes native starch, 450 000 tonnes of co-products including corn fibre and corn gluten meal, 100 000 tonnes of modified starch, 50 000 tonnes of L-lysine, 300 000 tonnes of starch sugar and 40 000 tonnes of compound fertilizer.

The Perten instruments are used throughout the process to monitor and control the same. Instruments are installed measuring the following:

  • Corn Germ after drying before storage
  • Gluten Slurry after separation before drying
  • Gluten Meal after drying before storage
  • Starch after separation, sieving and drying
  • Fibre before storage

Optimizing starch production through On-line NIR

Corn Germ measurement

The DA 7440 GP is located on top of the silo, in a by-pass configuration. The Measurement results are used to optimise the drying process to ensure consistent and optimum moisture content in the germ. Too high moisture content promotes mildew growth, which must be avoided. However, over-drying effect yield negatively and must be minimized.

Further, it is important to ensure a good product flow so the measurement is accurate and repeatable. A stochastic flow with wildly varying product thickness could make the measurement noisy, something that should be avoided.

To ensure a good measurement situation, the chute at a suitable angle where the product is slightly slowed to build thickness and ensure smooth running.

The DA 7440 looks through a glass window on which the corn germ runs continuously.

DA 7440 measuring corn germ moisture through a window DA 7440 measuring corn germ moisture through a window

DA 7440 measuring corn germ moisture through a window

DA 7300 installed in a vertical pipe, measuring gluten slurry after separation

Gluten Slurry measurement

The DA 7300 with the liquids interface is mounted on a vertical pipe with up-wards product flow. The measurement results are used to control the level of starch in the gluten stream. By continues monitoring, the operators can control and optimise the separation process to ensure only a small amount of permissible starch is present.

There is a sample port just underneath the instrument so samples can be taken out and analysed for instrument validation and calibration development purposes. 



DA 7300 installed in a vertical pipe,
measuring gluten slurry after separation

DA 7300 installed in a chute on top of the storage siloGluten Meal

The dried gluten meal is measured by a DA 7300. The instrument is mounted in a chute on top of the silo after the meal is dried, just before the storage.

The instrument is used to optimize the moisture content before the protein is stored. Too high moisture content promotes mildew growth, which must be avoided. However, over-drying effect yield negatively and must be minimized.

 

 

 

DA 7300 installed in a chute
on top of the storage silo

DA 7300 installed in a by-pass after starch drier & sifter

Starch

The moisture content in the starch powder is continuously measured after the drying and sieving, using a standard DA 7300. The line lay-out is such that the product path is vertical. This makes it difficult to install the instrument in the main path. Therefore, a by-pass pipe was installed and a diverter plate was fitted to ensure sufficient product would be diverted in to the measurement path.

The measurement results are used to control the starch drying and ensures a consistent end product.

 

 

DA 7300 installed in a by-pass
after starch drier & sifter

Corn Fibre measurement

The moisture content of the corn fibre is measured by a DA 7300. The instrument is mounted in a chute on top of the silo after the drying, just before the storage.

The instrument is used to optimize the moisture content to ensure the product is within specifications.

The amount of product in the chute is sufficient, but small. To ensure suitable measurement conditions at all times, two baffle plates were installed. These funnel the product to the measurement spot, thereby ensuring good measurement conditions and stable, accurate measurements.

DA 7300 installation point in a chute on top of the silo Baffle plates funnel the fibres to the measuring spot

DA 7300 installation point in a chute
on top of the silo

Baffle plates funnel the fibres
to the measuring spot

The Result

The instruments are connected to the plant control system and used to control the moisture content automatically. The variability of the moisture has been significantly reduced after installing the DA 7300. Hence, the final product is more consistent making further processing easier.

The results are viewed in the control room, from where the entire manufacturing process is monitored and controlled.

Optimizing starch production through On-line NIR - The result