Grinding / Classifying


According to the article titled “Fine Grinding and Air Classification of Field Pea”, field pea has approximately 23% protein, 48% starch, 8% sugars, 4% lipids, 7% crude fiber, and 3% ash.  This was published in Cereal Chemistry journal in 2005.  How do we implement this grinding and classifying process and automate it for maximum efficiency?  Sterling Systems & Controls, Inc. has designed and delivered a complete process control and automation system for the process of grinding and classifying field pea into usable flour, starch, and protein.

Included in the process control and automation system for this pea grinding and classifying project are:

  • Two (2) PLC/Starter Panels
  • Two (2) HMI Panels
  • Two (2) Mill Monitor Panels

In this Pea Grinding and Classifying project, there are two duplicate systems.

PLC/Starter Panel for Grinding / Classifying
PLC/Starter Panel (left side)

Sterling Systems & Controls understands the process, not just simply control technology.  We worked with the supplier of the mechanical equipment, our sister company and partner Prater Industries, to make sure the mechanical equipment would do the job required by the customer and we designed and manufactured the PLC/Starter Panel as required by the motors and electrical items that needed to be controlled.  In this case, 575VAC motor control was necessary and the electrical control design met this need.

There are two grinding and classifying processes controlled by the Sterling Systems & Controls automation equipment.  We housed the PLC and the electrical controls for each system within their own respective enclosure. The PLC and motor starters are networked with the HMI Panel via Ethernet.

HMI Panel for Grinding / Classifying

We know electrical controls and automation technology and can customize a system for our customers using standard control and automation components.  This is what we did for the grinding and classifying system in this project.  The HMI panel is the operator interface, when required, for the grinding and classifying system.  We use an Allen-Bradley PanelView Plus system running a custom designed FactoryTalk View ME application (main screen with classifying process running shown above).  The PanelView and PLC (in the PLC/Starter Panel) are connected via Ethernet and provide all control and equipment status information necessary to run the grinding process.  In addition to setting up security for each allowed operator (required to run the system) or administrator (required to setup parameters, and for running equipment manually), from the PanelView HMI you can:

  • Review the main grinding and classifying process screen (Figure 3 shown as when the system is operating)
  • Access and operate (MOA) each piece of equipment
  • Start and Stop the grinding and classifying process
  • Review and process current and historical alarms
  • Review equipment status: view current operating mode and the actual I/O points
  • Review and set system parameters
  • Review and set equipment and motor parameters
  • Review and modify formula (setpoints)
Classifying Mill Monitor Panels

In this application, the health of the air classifier mill is determined based upon monitoring of the inboard and outboard bearings.  Sensors check for bearing temperature, velocity, and acceleration.  The sensor signals are processed by a corresponding transmitter located in the Mill Monitoring Panel that converts, conditions, and outputs three (3) analog signals per bearing that are wired to the PLC in the PLC/Starter panel.  The transducers are intrinsically safe and safety barriers are included inside the Mill Monitoring Panel.


Working With Us

Give us a call today to talk about your business and process objectives and see how Sterling Systems & Controls can provide a custom engineered solution.  You can reach us by phone at 1-815-625-0852, toll-free in the USA 1-800-257-7214, or by email at