Automation can be an expensive business, but it can also provide a fairly fast payback
October 19, 2011 By Brian Weeks P. Eng.
No doubt about it, automation is an expensive business.
No doubt about it, automation is an expensive business. Although the price of the hardware is coming down nicely, the software and custom programming required is still expensive – especially if you are retrofitting an old plant. While we all know how automation can improve productivity and product quality, it is often hard to know where to start.
If you are looking at plant replacement or major upgrades, by all means look at the automation options available. Vendors will be happy to sell you the full package, but ask them to break the automation into components and do your own cost/benefit calculation on each stage. That way you can find the best payback on the expense. You may be pleasantly surprised at how good it can be once you factor in the additional tonnes per hour, better plant uptime, better maintenance predictability and better product quality. Don’t assume you will be able to save labour – often the same labour man-hours get transferred to better maintenance.
If you are considering retrofitting automation to an old plant, the same sort of staged analysis is even more important. The reality is the same as it has always been – “garbage in, garbage out.” In our context, you cannot automate your way out of a plant that has inherent problems. Automation will make a good plant better, but a poor plant worse. Your best payback is going to be anything that increases your plant availability or “up time.” Fix those conveyors that stall out in the rain. Fix the drive motor that overheats when the unit is run to capacity. Fix the chute that plugs up because of lack of maintenance. Fix the . . . well, you’ve got the idea. Then, and only then, look at automation options.
Here are a couple of ideas for using remote communication to take “baby steps” into automation. First, consider remote cameras. In every plant, there are areas where the plant operator cannot see problems as they occur. Small, very robust CCTV cameras are now down to the $300 range. They run on tiny plug-in 12 volt DC supplies and can be wired (or, for a bit more money, wirelessly connected) to a multi-camera switcher unit and display monitor at the operator’s station. If you do not want to record the signals, $4,000 to $5,000 would provide a very practical package at many plants. What would you save in a year if the operator could see those problems and shut the plant down before conveyors or crushers got buried or product stockpiles got contaminated? If you wish to take this to the next level, the camera signals can be fed into a router, which would enable your staff to look at the signals from anywhere in the world that they can access an Internet connection.
Another comparatively inexpensive idea is to use radio remote controls. For safety reasons, you need to be sure you get properly secured and encrypted units, not just a re-purposed garage door opener.
Typically, a battery operated hand unit will provide six to eight channels (i.e., signals) that will work up to several hundred metres from the receiver. The receiver gets wired into your existing controls to suit the functions you wish to control remotely. At one of our plants we provide the loader operator with a handheld unit that can: start and stop the plant in a controlled manner; panic stop the plant in an emergency; cycle the grizzly on the feed hopper and start and stop the feed to the plant. Not all of these functions might be practical in your application, but you don’t need to configure all channels initially. This idea is harder to price, as installation costs will depend on the complexity of the controls you already have, but the hardware costs about $2,000 so $4,000 to $5,000 would likely give you basic functionality including installation. This hardware can improve both productivity and safety without too much cost, so be creative.
Brian Weeks is the Aggregate Producers Association of British Columbia’s secretary and a director.
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