Coal Age

JUN 2019

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June 2019 23 slurry pumps continued The internet connection also en- ables the customer to push data from the meter to a database hosted by Red Meters. "It allows for cloud storage of data if that is something that you would like," Ornstein said. Perhaps more importantly, the internet connection allows a user to contact Red Meters for assistance in installation, calibration, program- ming and support. "Remote support is the newest offering by Red Meters that we are really excited about," Orn- stein said. "Downtime is something we don't want our clients to have be- cause of the Red Meter at all." He described mechanical instal- lation of the meter as "simple," but where the "intricacies of what we do comes in is in the electronics." With access and approval from the customer, Red Meters can remotely address issues with the computer and assist with calibration "on the client's schedule," Ornstein said. "When the client is ready, that is when we go to work." The evolution of the V2, steered by "hundreds of whiteboard sessions," centered on an effort to simplify in- stallation and support, Ornstein said. "The early-stage thought was how could we get into the unit to do the startup and to do the troubleshoot- ing, because it will take our guy 20 minutes and they'll be much happier and it will be easier for us," he said. "And then the question arose of what else can we do with this? What other avenues and doors does connectivity offer? What else can we provide for our clients with that connectivity?" One answer was upgrading the computer to take live outputs and historical readings and "totalize the targets," the company reported. "When we were selling a density meter, we were just establishing den- sity based off of a volumetric mea- surement and a weight measurement and just using the other ancillary in- formation internally in our system," Ornstein said. "The reality is that those are also useful datasets for our How to Avoid Common Shaft-Sleeve Problems Shaft sleeves are cylindrical metal tubes designed to protect pump shafts from erosion, corrosion and wear at critical points, such as at the stuffing box. The shaft sleeve is a wear component, like brake pads on a car, and is designed to be more cost effective to replace than the shaft itself (like the entire braking system). A slurry pump user recently discovered during an inspection that dirty seal water had cut their shaft sleeve in half, causing a leak. As a temporary measure, the millwright tightened the sleeve and moved it inward; however, this caused a secondary wear pat- tern and did not stop the leak. A second tightening prevented the sleeve from rotating and caused a horizontal wear pattern in one location. By this point, they should have realized that the sleeve was beyond repair. If wear patterns have already formed on the shaft sleeve, moving it will only worsen the wear and cause new wear patterns to form in the area relative to its original cause. To better understand this, prep plant managers should think of slurry and contaminated sealing water like liquid sandpaper. Both can be highly corrosive and abrasive. Moving the shaft sleeve will only relocate the groove and initiate the generation of another one. Tightening the gland compresses the packing and reduces the cooling effect of the sealing water. Over-tightening it will make matters worse and can lead to component failure. To prevent failure from occurring, maintenance personnel can take a few steps to diagnose and solve problems with the shaft sleeve before it wears out. This diagnostic should be a part of routine pump maintenance to avoid early sleeve replacement. The first step is to inspect the sealing water system for ad- equate flow, pressure and quality. GIW recommended clean seal- ing water at a sustained pressure of 10 psi above the discharge pressure of the pump. The higher-pressure sealing water will pre- vent the pumped medium from weeping back into the stuffing box, thereby mitigating shaft sleeve wear. If the flow and pressure are within specifications, check the sealing water for corrosive proper- ties and/or abrasive particulates. The shaft sealing system must be designed and applied according to the parameters for the pump. If the shaft sleeve is worn beyond repair or leaking, it may be time to replace it. Fortunately, shaft sleeves are designed to be more time- and cost-efficient to replace than the entire shaft, making replacement a "no brainer" as far as cost and repair time are concerned. Shaft sleeves are available in different materials to combat all combinations of wear and corrosion. If a shaft sleeve is worn to the point of leakage, a plant manager should consider replacing it. While replacing the sleeve is easier and less expensive than replacing the entire shaft, the process can interfere with production. Therefore, it's important to exercise best maintenance practices to extend the life of a shaft sleeve. Understanding what contributes to shaft wear and know- ing the specifications of a particular pump related to flow, pres- sure, and sealing water could pay dividends in the long run. This article was adapted from a GIW post on the KSB at Tightening the gland compresses the packing and reduces the cooling effect of sealing water and over-tightening will only make matters worse. (Photo: KSB/GIW)

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