Flow Transmitter Provides Measurement Certainty to Liquid Fertilizer Manufacturer

2015 Flow Control Innovation Award Winner:
Model 5700 Advanced Field-Mount Transmitter — by Emerson Process Management – Micro Motion

Nutra-Flo is one of the largest independent liquid fertilizer manufacturers in the Midwest. Its mission is to provide innovative fertilizer products and reliable service that satisfies growers’ needs throughout the United States and Canada.

One of the critical applications in its process is the measurement of black phosphoric acid into its fertilizer mixtures. This application poses several challenges that Nutra-Flo has managed to address with the use of the Micro Motion Model 5700 Coriolis Flow Transmitter from Emerson Process Management.

One prevalent challenge across this application, as well as others throughout the process, is the inherent difficulty of interacting with flow transmitters. Typically, local monitoring and operation of a flowmeter involves complicated menu interaction, poor display information, and cumbersome interface controls. The intuitive flow of menu screens, large graphical display, and four-button navigational interface of the 5700 has increased productivity and reduced troubleshooting time and technical support needs.

The need for multiple variables from the flow measurement point is also key to this process. The control and quality monitoring requires not only flow rate, but density and temperature as well. The availability of these variables is one of the benefits of Coriolis flow measurement technology, but often it is an integration challenge to bring them all out of the meter and integrate into the control system. Due to the broad flexibility and type of I/O channels available with the 5700 transmitter, Nutra-Flo was able to obtain the exact combination of process variables directly from the transmitter in the format its control system needed, removing the typical capital expenses of additional signal converters, instrumentation or input cards.

The biggest challenge with Nutra-Flo’s black phosphoric acid addition stems from the need to measure at a large range of flow rates depending on the particular mixture. As a result, the application often operates at a high turndown at the low end of the flowmeter range. When operating at these rates, the importance of a proper meter zero is magnified, and an improper zero can result in increased variability. The Model 5700 transmitter contains a new self-test diagnostic called Zero Verification, which addresses these concerns. Zero Verification provides an analysis of the current meter zero to determine if it is within an acceptable range and properly applied. Additionally, if a new zero does need to be established, it provides several checks of the process to ensure that conditions are quiet and stable so that a new zero does not inadvertently create an issue.

"The Zero Verification tool is very important to us," Nutra-Flo reports. "This process is the very heart of what we do, and when we operate at the low end it is critical we have certainty in the measurement. Due to the confidence from the 5700 transmitter we have been able to reduce our planned maintenance schedule on the meter to an as-needed basis as opposed to scheduled verification."

The Final Results:

• Meter installation and commissioning time reduced by more than 50 percent.

• Capital costs reduced by $1600 by removing need for additional system components.

• Elimination of costly scheduled verifications of the flow-meter by use of included diagnostic tools.

Read more case studies from 2015 Flow Control Innovation Award winners here.