Weighing In

Concrete across the continent

Cement, water, and aggregates are the primary components for making concrete for storm drainage/retention structures, gravity pipes, precast bridges, and many other concrete items.

A customer of J. McCoy and Oshawa Bearing is one of the largest manufacturers of concrete products in North America. This company manufactures concrete pressure pipes and pre-stressed bridge girders. Its products form the backbone of roadways, highways, and drinking water systems.

In the concrete manufacturing process, the precision of the recipe dictates the quality of the finished product; full reporting of every batch for CSA and MTO is an absolute requirement.

Materials that are stored in multiple bins are monitored using weighing systems to accurately control each ingredient in the right amounts. Using microwave moisture sensing, the Siemens PLC adjusts target weights to compensate for the water content within the aggregates and, in turn, adjusts the water target in the mixture.

Concrete integration

Working with J. McCoy Equipment, Oshawa Bearing is a long-standing Siemens automation technology user.

Why Siemens? Many years ago, the company decided to use this technology when a customer requested that its solution include a Siemens PLC. Since then, the company has adopted Siemens as its solution partner to provide multi-vendor integration for motor drives, weighing technology, instrumentation, and PLCs.

It found that the Siemens solution integrated many vendors, which was a plus when working with many different products.

Within the Siemens Totally Integrated Automation (TIA) portal, Oshawa Bearing is able to seamlessly integrate the following technology into the manufacturing process:

• A SIWAREX WP231 weighing module.
• A SIMATIC S7-1200 PLC.
• Third party instrumentation and motor controls.

High accuracy for high performance

The SIWAREX WP231 weighing module for static weighing applications integrates seamlessly into the SIMATIC S7-1200 bus, providing weighing information and calibration settings within the automation programming.

With its 2 million part analogue-to-digital converter, the module provides very high accuracy weighing solutions with analogue load cells.

As a bonus, SIWAREX WP231 includes analogue output, as well as digital inputs and outputs that can be used within the control system for various tasks.

“It all just works”

With the SIWAREX weighing modules and its integration into the automation system, operators save on calibration effort, providing information throughout the plant.

No longer do operators need to physically zero and calibrate the hopper scales, but instead can diagnose issues and perform calibrations from the control room or a local human machine interface.

This solution does not require analogue input cards and needs no specialised displays, as all information can be wired to any user displays onsite, including tablet computers through plant WiFi.

“It all just works,” said John McCoy, President of J. McCoy Products. With TIA Portal and this flexible weighing module, the integration of devices from multiple vendors within this automation project was very quick and easy within one software tool.

Easy-to-access information

Another benefit operators have found is in the digitalisation of the weighing readings: there is no scaling or loss of resolution, and no troubleshooting adjustment pots or summation electronics.

In addition, useable information, such as instrument diagnostics, plant operating statistics, and plant efficiency is now at the operator’s fingertips. Scale performance and other crucial information can be seen in the control room and recorded for quality and traceability requirements.

If a problem with a piece of equipment or a certain process occurs, operators know instantly and can fix the issue quickly before it impacts the manufacturing plant’s performance.

From the plant to a city near you

In some of J. McCoy and Oshawa Bearing’s other projects, plant designers use SIMATIC S7-1500 and SIWAREX weighing modules, along with other vendor instrumentation and controls.

The biggest impacts to these projects are the operational efficiencies that the concrete plants enjoy with the speedy and simple calibration process, which help to ensure calibrations are performed more efficiently.

With the simplicity and high performance of the TIA Portal, Siemens automation components, and the weighing modules, partners at J. McCoy Equipment and Oshawa Bearing can spend more time developing innovative solutions and increasing value for their customers across North America.

About the author

Located in Peterborough, Canada, Matt Morrissey is a Product Manager at Siemens, specialising in ultrasonic level measurement and weighing instrumentation. Morrissey has over 15 years of experience in process instrumentation and holds professional designations as a certified engineering technologist, project management professional, and certified product manager.

Read the article online at: https://www.worldcement.com/special-reports/01022019/weighing-in/