APM Q2 Newsletter - Volume Measurement Improves Plant Efficiancy

Welcome to the April Newsletter.
For the last five years APM has been changing the market from level to volume, helping many customers realize multiple benefits from this move. These benefits include smother operation flow, easier decision making, waste elimination and to top it all off, reduced costs and improved earnings.

Tracking level in bulk solids using single point devices is extremely inaccurate, as solids do not level out and tend to build up.  This leaves operations people with too little information for the day to day decision making, such as when and where to fill or empty, when to order or when can they schedule maintenance. Management is also adversely impacted as capacity forecasts, cost calculations and inventory reports are all based faulty data. Using true volume data not only solves these problems but generates many more opportunities for savings and improvements.

Inaccurate measurements increase the need for safety stocks just to ensure there are no line downs. Yet this safety stock cant be managed, since it cant be accurately measured. This can lead to early ordering, which result in spill outs or costly returns or late ordering, which result in line downs.

The most immediate impact achieved when improving accuracy by moving from level to volume is the reduced cost of carrying this safety stock. Carrying costs include the costs of handling the inventory, obsolescence, deterioration & pilferage as well as the taxes, insurance costs and cost of money. These costs can be as high as 50% of inventory value on hand for bulk solid materials, though most organizations use 25% as a ballpark figure. These high costs are a direct result of the need to protect against high levels of uncertainty generated by level measurement in bulk solids. Increasing the accuracy by measuring true volume significantly reduces the uncertainty, so safety stocks can be reduced accordingly reducing the carrying costs substantially.

Here are some real life cases that demonstrate the wide variety of additional benefits gained when moving from level to volume.

AngloGold Ashanti Case Study

AngloGold Ashantis Moab Khotsong gold mine in South Africa had issues with the gold ore and waste silos. The silos contain high value materials and control of silo content is crucial to allow production flow and process control.
Volume control is also important for
reducing silo maintenance costs. These silos have grizzly bars at the bottom that must be protected against the falling rocks and gravel entering the silo by a  minimum level of material coverage.

AGA tried several single point radar solutions, such as Vega and Siemens before testing a 3DLevelScanners model MV. Moving from level tracking to highly accurate volume readings and 3D graphic output the operation team was finally able to protect the silos Grizzly Bar outlet by making sure that not only was there enough material in the silo to protect it, but that the material was spread out with the right profile to generate this protection and was covering the outlet entirely. It was also the first time they were able to track build up as it occurs over time, eliminating cases where production reports the silo as empty when, in fact, it has bridges or blockages.
More than that, by tracking true volume, management could control reef (the raw material) quality in real time for the first time ever. By comparing reef volume to waste volume the water % in the reef can be calculated and compared to the specs. With this data available lower than expected output can be analyzed and the correct corrective measurements taken.

LDC Ethanol Case Study

LDCs ethanol plant converts shelled corn to ethanol  and dried distillers grains (DDG) using silos to store the shelled corn and the DDG. The silos were tracked using guided wave radar, with manual measurement used for backup, to ensure data correctness. Maintenance costs were high due to repeated break downs of the radars cables. On top of this LDC knew that due to multiple filling and emptying points the material has irregular topography but they could not monitor the areas of high and low material in the bin.

LDC decided to move from level to volume in order to improve inventory accuracy. The non contact technology also meant significant reduction in reactive maintenance due to cable break downs. With the new technology they could ensure adequate safety stock, guard against shortages and supply disruptions, reduce labor costs due to manual backup measurements and overtime in the receiving operations. It also allowed them to track grinding rate in real time by comparing the empting rate of the corn to the filling rate of the DDG.
All these benefits, as well as the improved accuracy in reporting to corporate offices, moved additional LDC sites to implement the 3DLevelScanner technology.

Brewery Case Study

A major US manufacturer of fine malt beverages  needed both accuracy and stability in measuring whole distillers rice. The customer was using radar systems in the bins and was not pleased with the results. The primary
concern was headroom (distance to product), with bins emptied almost completely before filling to prevent product damage. Additional concerns were the ability to measure during filling and emptying and the materials tendency for rat-holing and bridging.

Moving from level to volume by fitting all the bins with MV scanners generated more precise headroom data thus generating better inventory control. Mapping and visualization of material prone to bridging and rat holing allows correct timing of maintenance and reduces material loss due to rotting. The ability to monitor multiple bins with one solution reduces the time spent on this, freeing the operators time for making the correct decisions.
All this allows the brewery to maximize bin utilization, reduce waste and increase the profitability. The 3DLevelScanner has now become the bench mark solution for the company.

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