Jim ‘Slim’ Mimlitz, SCADAmetrics
At many pumping stations, production wells, filtration plants, and custody transfer stations, it is often desired to add chemicals (such as hypochlorite, for example) to the water flow.
Whenever chemicals are pumped into a pipeline, it is important for the utility to ensure that the chemical flow is a fixed proportion of the pipeline flow. Thereby, when the pipeline flow varies up and down, then the speed of the chemical metering pump will be varied up and down to match, accordingly.
Signalizer Solution — Converts Encoder Meter to 4-20mA
The pipeline flow can be monitored with an inline flow meter with a high-resolution encoded output, such as the Neptune HP Turbine with ProCoder register. In order to generate the required analog flow pacing signal, a SCADAmetrics model EMP Signalizer will leverage the encoded signal from the ProCoder to create a fast-reacting (1 second) 4-20mA signal. Note that this solution requires an encoder-type flow meter/register that can tolerate high-frequency interrogations (i.e. 1-3 readings per second):
Analog/Pulse Kit Solution — Converts Pulse Meter to 4-20mA
Alternatively, if the inline flow meter is not an encoder-type, but rather a high-resolution pulse-output type, then a SCADAmetrics model APK Analog/Pulse Kit may be used to generate the required 4-20mA chemical pacing signal:
Regardless of whether the chemical feed is controlled by a Signalizer (w/ Encoder-type flow meter) or an Analog/Pulse Kit (w/ Pulse-type flow meter) — a modular control architecture is achieved, providing the customer with the following benefits:
- Use of a Standard, AWWA-style Flow Meter is Possible, Rather than a Specialty 4-20mA Flow Meter.
- Hardware-Only Solution — No PLC (Programmable Logic Controller) Programming Required.
- Signalizer and Analog/Pulse Kit Provide Optically-Isolated Power and I/O Circuitry for Superior Lightning Protection.
- DC Low-Voltage Wiring for Increased User Safety.
- Compact, DIN-Rail Footprint Signalizer or Analog/Pulse Kit, for Easier Integration inside the Control Panels.
- User-Settable DIP Switches Allow Signalizer or Analog/Pulse Kit to be Used with Various Flow Meter Models and Sizes, Eliminating Need for Factory Programming.
- User-Selectable 4-20 Milliamp Span (Digitally Self-Calibrated).
Want to Learn More?…
Are you interested in learning more about how SCADAmetrics flow instrumentation can be leveraged to pace chemical feed pumps to match the pipeline flows, thereby achieving a constant PPM dosage? Give us a call!… We’ll be glad to discuss the details!