Aggregates Manager Digital Magazine
Issue link: https://read.dmtmag.com/i/674527
Master the Balance Between Man and Machine OPERATIONS M ore and more pro- ducers are adding automation to their operations — not only with new plants, but also as part of retrofi tting existing operations. Au- tomation can provide anything from basic machine control to a high level of process control to maintenance and service control. Moving beyond single-machine control, a whole- plant system automates the entire plant so that all of the equipment, from the primary to the fi nal convey- or, communicates well with each other — essentially acting together as one machine. Total plant automation includes feed control, startups and shut- downs in the proper sequence, and automatic plant monitoring for problems and data collection. Running the plant manually can be diffi cult. The operator must pay close attention to plant fl ow and monitor everything manually because he doesn't have all of the data that is available. In compari- son, an automated system monitors all equipment and catches issues quicker than an operator can, and it can stop the plant — in the proper sequence — before any catastrophic damage occurs and without the risk of messes and cleanups. Whole-plant automation pack- ages help improve plant effi ciency through real-time monitoring that maximizes productivity and reduces downtime. It does this by helping identify bottlenecks, tracking equip- ment performance, and trouble- shooting problems. From a proactive maintenance standpoint, an auto- mated system helps schedule and plan preventive maintenance. From a service standpoint, data trending helps operators troubleshoot and then plan a plant shutdown and order parts before a failure occurs. A whole-plant automation system can certainly be specifi ed and built into a new plant, but a retrofi t on any plant is possible. Most existing operations that choose to automate their plants discover the automation package can be installed with little or no modifi cation to the existing equipment. "'Why should I automate?' used to be the main question received by producers when we would meet about potential projects," says Matt Etheridge, president of Etheridge Automation. "We used to have to sell the concept more. But most produc- ers, at this point, know it is better to have it — from the standpoints of effi ciency, production, safety, and maintenance." According to Arnold Connelly, Jr., area manager of aggregates for Tilcon New Jersey, "With the old school way of operating equipment manually, the operator would use amp draw in combination with 'slug- ging crushers' in deciding whether to tighten the crusher to maximize key products. But it's not a reliable or effi cient operating method, and it often requires longer operating hours. A totally automated plant will usually lower your operating hours and increase throughput." AGGREGATES MANAGER An automated plant will run at the optimal speed without overloading equipment. Because an automated plant is interlocked between all equipment, if there is an issue, it can shut itself down quickly in the proper sequence. Most stages can run unmanned, reducing the overall amount of manpower required and taking the plant from two or three operators down to a single operator. The system can also see maintenance issues and alert the operator before the plant breaks down. Plants that start, stop, and run manually almost always run at less than optimal production. The only real control an operator has after starting the plant is the speed of the feeders. Segregation occurs often within surge piles, creating fl uctuations in material to crushers and constant gradation changes. To ensure that the plant doesn't have problems, the operator will run the feed at an "operator comfort zone" speed to handle the variables. Old school: Manual controls Improve safety and maintenance 1 4