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Scale-Tron Inc. installed SiloWeigh.Net for Lafarge-Holcim in Coquitlam, BC Canada in July 2016. The trial determined the effectiveness of the system at highlighting stock discrepancies in both regular and split silos. Some of Lafarge-Holcim’s plants have relatively small silos and running out of material impacts the company and its customers. After an extended trial period, Lafarge Holcim’s Greater Vancouver Area manager said that “this was the only plant in their area that never ran out of material and never overfilled its silos”. The consequence of overfilling is bursting of the filters, with clouds of cement dust spreading over the landscape. As a consequence of the good results, Lafarge-Holcim ordered SiloWeigh.Net systems for all nine of their Greater Vancouver Area plants.
Installation was carried out by their own staff between November and December of 2020. As part of this program, Scale-Tron updated its web-based remote user interface, allowing Lafarge’s bulk material ordering team to view all silos, at all sites, through a single web browser making material control and ordering more efficient.
The installation of Lafarge-Holcim’s SiloWeigh.Net systems
Scale-Tron’s L-Strain sensors are fully temperature compensated, like load cells and bolt onto the silo legs or skirt. These are usually steel but can equally be stainless steel or aluminum. SiloWeigh.Net can be installed on divided silos of any ratio, stacked silos and silos on a shared frame.
Lafarge-Holcim’s maintenance team bolted the sensors in place and tightened them using a torque wrench. They then wired them to a “Digital Junction Box” mounted on each silo. Next, they wired the silo DJBs in daisy-chain fashion, using a single cable, to the display cabinet. For SiloWeigh.Net, this cabinet houses the Data Acquisition (DAQ) board, embedded computer and optional touch screen. Lafarge-Holcim has chosen to use a conventional computer display, keyboard and mouse, on lower volume plants. High volume plants added the panel mount touchscreens for ease of use. The embedded computer connects to the plant network and through this to the Internet. Remote users with the appropriate username and password can access locations via a web browser.
The results from SiloWeigh.Net Maple Ridge
Weather filter eliminates sun effects but allows fast fills & discharges.
SiloWeigh.Net shows all silos at the plant as bar-graphs on one screen. Clicking on any silo shows a trend graph of the last 24 hours of use. This can be zoomed to a week or a month display or a selectable date range.
Bar-graph display changes color at each alarm level.
SiloWeigh II and SiloWeigh.Net both have an advanced weather filter which improves the accuracy greatly during periods of bright sunlight. SiloWeigh is the only system on the market with this filter.
Other systems available on the market display the raw readings and consequently can show large errors. The use of level sensing systems does not offer the accuracy required due to errors caused by material rat holing, bridging and material compaction.
The operator at the Maple Ridge plant monitors the inventory and uses it to reorder his materials. To help with this, the bar-graph display changes color at the four programmable alarm points: Reorder, Low, High and Overfill. Optional hard-wired alarms are also available to illuminate lights, sound horns or activate a pinch-off valve during filling.