Featured Project – Schnitzer Steel Mega Shredder (Portland)

In the summer of 2007 Schnitzer Steel Portland began running a massive metal shredder on their site.  Monitoring this highly destructive machine was important to production; however, this was a very dangerous task.  Electronic surveillance was the best solution to ensure employees would not be injured by flying debris.  When the mega shredder was being constructed, a competitor was contracted to install a series of cameras to help shredder operators see into the machine while it was running.  Operators would also need to see employees working around the machine’s many belts and magnets to prevent any injuries from taking place.

Issues began only weeks after the shredder’s initial startup.  Crewmen would need to regularly stop production to clear or repair cameras that were subject to constant bombardment.  When it rained, the cameras were blinded by thick plumes of steam generated by the extreme heat in the shredder, and managers were unhappy with the lack of remote playback and live viewing available from this system.

Pixel was chosen to quickly reengineer the video monitoring system due to previous success installing the yard’s surveillance system.  The first order of business was getting the cameras linked to the Pixel DVR that was installed to monitor the cameras in the yard.  Fiber optics had been installed between the server room and shredder building when the shredder was raised.  We used a 16-channel fiber optic video transmission module to transfer signals through this connection.  The DVR was upgraded with 16 additional channels to give the recording capacity needed to view and play back the shredder’s cameras.  Managers now had access to all 16 cameras currently installed at the shredder.  Utilizing a KVM switch we previously installed, playback and monitoring of this system was now available at their desks.

New stainless stell housings were selected for the cameras closest to the shredder.  These housings provided resistance to the corrosive elements in the air and also had the strength to repel the shrapnel constantly flying about.  In order to reduce the need for repeated cleaning during operation, these housings were equipped with wipers and fluid sprayers.  By simply pushing a button, the face of the camera enclosure could be wiped clean.  Fluid was fed to the enclosures through a custom-built filtration and pumping circuit designed and installed by Pixel.

Of all the cameras installed, none was more impressive than the PTZ mounted high atop the shredder’s control cab.  This stainless steel camera and motor assembly gave the same environmental protection the other cameras offered. The added bonus with this camera was the ability to see everything taking place around the shredder.  The same wiper and washer setup was included with this housing.  Controls for the PTZ and wiper/washers were placed at the operator’s chair.  Here we installed a touch screen keyboard that used a 16-channel multiplexer to view different cameras individually, or in split-screen configuration.

The last problem of seeing through steam created by the shredder was solved with the use of infrared cameras.  Two cameras were installed at opposing locations to allow viewing without restriction.  The first infrared camera was custom mounted directly on the shredder shoot and looked into the mouth of the feed roller.  The second camera was mounted on a movable service arm on a wall in front of the feed shoot.  The two angles provided operators with live views of the shredder’s shoot preventing costly shredder jams.

Completion of this system has given Schnitzer Steel a reliable method of monitoring shredder operations.  Man power is no longer wasted maintaining cameras allowing more attention to be given to keeping the shredder running.  Finally, managers were seeing what the operators were seeing, helping to increase productivity and ensuring safe work practices took place.  Schnitzer Steel has been happily using this system for several months now.  All of the problems experienced before the upgrade have been solved thanks to Pixel engineering and installation expertise.

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