Clamp-On Ultrasonic System Solves Slurry Flow Measurement Problem
In the mine’s existing setup, the flow of copper pulp slurry running through a 14- in. (DN 600) pipeline was measured by an electromagnetic flow meter that was maintenance- intensive due in large part to the rubber liner fitted to the flow meter. The liner was meant to reduce abrasion on the inside of the pipe but given the harsh nature of the copper slurry and the very high content of suspended solids (65%), the electromagnetic flow meter had to be replaced almost every year.
Because the electromagnetic flow meter was of the inline type, changing it was not an easy task. Operators had to shut down the entire process while the old flow meter was removed and replaced with a new one. Doing this was both time-consuming and expensive both in terms of the required manpower as well as lost production output.
In seeking an alternative measurement
technology able to deliver the key performance
requirements of low maintenance and
easy installation the miner contacted
Siemens, which recommended a flow meter
based on clamp-on ultrasonic technology
with sensors mounted on the outside of the
pipe and an accuracy in the 1%–2% range.
This solution, according to Siemens,
offered several benefits for the customer.
• The flow meter could be installed without shutting down the process.
• The sensors would be mounted on the outside of the pipe, separated from the abrasive fluid contents, eliminating the wear problems that accompanied the electromagnetic flow meters. An annual liner or sensor replacement simply became unnecessary.
Before making a final decision on whether or not to purchase the system, a Siemens team brought in a portable check metering kit, the Sitrans FUP1010, to conduct an initial test. The check meter was installed on the pipe and programmed in less than 20 minutes to measure the flow, promptly demonstrating its easy installation, reliable performance and capability of measuring the very thick (65% solids content) copper slurry. Impressed with how quickly the sensors were installed as well as by overall performance, the company decided to install the dedicated version of the portable check metering kit, the Sitrans FUS1010, with permanently mounted sensors.
An additional key feature of the Sitrans FUS1010 is its ability to measure flow by two modes of operation: WideBeam transit time and Doppler. Transit time operation offers an accuracy of up to 0.5% of flow and is the preferred mode of operation for relatively homogeneous liquids. Doppler operation, on the other hand, is designed for slurries with extensive suspended solids, with 1%–2% accuracy. According to Siemens, having both modes of operation ensures suitability for virtually any mining or minerals processing industry application because the system can be set to automatically switch from one mode of operation to the other, eliminating any need to change meters.
Information for this article was provided by Sheldon Shepherd, marketing manager for industry business development within Siemens’ Sensors and Communications division.