Foundations™ Learning Center

Foundations Learning Center

Below is a list of all the blog posts you are posting that your
visitors might be interested in...

Investigating the Problem: The Belt Conveyor Survey

The first and most important step in training a conveyor is to check and align the structure. The best way to begin this process is to make a detailed survey of existing conditions and the original design criteria. This allows measured corrections to be made returning the system to original specifications, rather than adopting an unplanned “let’s ‘tweak’ the idlers a little more today” approach.

The traditional method of checking alignment has been to stretch a piano wire from one end of the conveyor to the other and use this wire as a baseline to take the measurements to evaluate alignment. However, this method has a number of potential problems. For example, the wire is vulnerable to shifts in its line. Changes in ambient temperature from the warmth of the sun, or even the actual weight of the wire itself, can stretch the wire, changing the line. Another problem is that there is no accurate way to measure a 90-degree angle from the wire. If the wire moves when touched when laying a ruler square against it, the accuracy of subsequent measurements is destroyed.

Conveyor, Belt Support, People, Inspection Crew

Now, high technology, in the form of beams of light from a laser transit set in parallel to the conveyor structure, provides an unobstructed and repeatable reference for the alignment of the conveyor-structure components.

This laser-surveying technology avoids the problems encountered with the old “piano wire” technique. The laser generates a perfectly straight beam with an effective range of 150 meters (500 feet), with multiple set-ups allowing unlimited distance. To check objects set at angles to the baseline, prisms can be used to bend the beam. With a laser transit, the survey crew is no longer trying to measure a perpendicular line; they have created one. Since a laser beam cannot be touched, it cannot be moved accidentally when taking readings from it.

A comprehensive belt conveyor system survey can identify opportunities to improve system performance, increasing productivity, lowering the cost of operation, and improving safety.

Most operations do not have the equipment and expertise to properly conduct a laser survey. Therefore, it is in the best interest of the operation to hire a specialty contractor or service with the hardware and experience to conduct this survey. A specialty contractor will laser survey the belt, inscribe a permanent series of benchmarks or alignment points, create a detailed report, and offer recommendations as to how to correct the major tracking problems.

The report should tell which components are out of alignment and by how much, so the plant maintenance crew or the specialty contractor can adjust these components to improve the belt’s tracking. By doing repeat surveys of the same conveyor at regular intervals – annually, for example – plant management can provide a regular check of the condition of the conveyor structure. The survey will tell if the structure is deteriorating or if other circumstances – such as subsidence of the ground under the conveyor or change in the counterweight mass – are occurring. This information can be used to prevent unexpected shutdowns and subsequent loss of production by alerting the plant’s engineering and maintenance staff to problems as they develop.

Topics: Conveyor Belt Mistracking, Belt Conveyor System Maintenance

Leave Comment