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Starch Moisture Sensor

Intelligent Moisture Sensors for Complex Starch Manufacturing

While starches can come from a variety of sources and vegetables (rice, potato, tapioca, etc), a great percentage of starch is made from corn. When finished corn starch is stored before shipment, it resides in silos where the moisture content must remain in the 9-12% range to prevent microbial growth, and to keep the product’s shipping weight in the appropriate range for the necessary amount of product.

Maintaining this range can be accomplished by either Near Infrared (NIR) or Radio Frequency (RF) moisture meters, but it’s important to understand what is needed to utilize either moisture sensor effectively. Since the product is in a silo, a sight glass would be needed for NIR measurement.

Employing a radio frequency sensor (RF Probe)

The RF Probe type meter however, provides a probe (of any appropriate length) that is inserted directly into the silo. The mounting location would be near the bottom of the silo so that the product would always be surrounding the probe. The probe mounts through a 3/4 in. NPT flange that’s welded onto the silo. The probe then simply screws into the flange. The RF Probe is a radio frequency device that generates an RF field of about 3 inches in diameter surrounding the probe. The starch would then need to move past the probe as the silo was filled and emptied. Continuous moisture content would then be displayed on the Smart III touch screen display with current or Ethernet outputs to the control rooms PLC or DCS for closed loop moisture control of the drying operation prior to silo storage.

This finished starch, with the proper moisture levels maintained, can then be utilized in a large number of other manufacturing processes where moisture ranges play and equally critical role in the success of the product’s creation.

RF Probe

Smart III RF Moisture Probe is appropriate in those situations where NIR use on conveying systems/web applications or RF flat plate sensor use on board type products are not sufficient.

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Starch Production Blog

Read more about how the RF Probe is driving greater throughput, quality and energy efficiency.


Employing a near-infrared sensor (NIR)

Consider, for example, corn starch being used in the moulding of gummy bear and sucker type candies in the confectionery industry. In this use, metal trays are filled with starch and indexed via conveyor belt under a SS dye. The dye then descends into the starch, forming the shape of the candy. If the starch is too wet (greater than about 10%), the starch sticks to the dye and if it’s too dry, the walls of the mould’s depressions crumble. Either problem results in defects that require product discard, waste, recycle, downtime, cleanup labor, and increased utility costs.

Employing a near-infrared sensor (NIR) at this point in the process saves you from losing product, labor, and utility costs unnecessarily. Our OMNIR near infrared sensor is mounted over the starch tray as it is indexed under the dye. Instantaneous moisture content is then displayed indicating to the line operator if the moisture content is in the acceptable range to avoid these product defects. Since the starch is recycled for subsequent tray filling, it must be kept at the targeted moisture level to assure perfect candy formation.

In the wet milling process, corn germ is separated and dried to the 5-7% moisture range. Gluten is later removed by centrifugal force and then dried. Both these locations also require on line moisture meters to maintain that strict range.

Explosive Dust

When it comes to starch manufacturing, the stakes are higher than in some other industries due to one particular issue: explosive dust. Because of this danger, adhering to the strict moisture levels as required by OSHA, EPA, and local health and safety regulations is incredibly critical. There must be enough moisture to eliminate the risk of explosive dust, but not enough to encourage microbial growth or other moisture-related issues that can cause major loss of profit, time, and labor.

Finna Sensors OMNIR sensor is available for instantaneous moisture measurement for all the many needed drying locations within the starch manufacturing process.

OMNIR for Starch

The OMNIR On-Line Near Infrared Moisture Sensor not only delivers accurate data instantaneously and non-destructively, it also monitors its own health to help keep your operation running smoothly. Click the button to see how Finna Sensors can assist in augmenting your starch process.

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