Reliable Flow Measurement for Recycled Oil and Water Mixtures

Using recycled oil as an energy source poses a challenge due to its inconsistent composition and potential impurities. Conventional flowmeter technologies are impractical in such cases. The CA Series, however, reliably and stably measures the flow of recycled oil mixed with water.

 

Challenges

A cement producer using recycled oil as kiln fuel faced challenges with a Coriolis mass flowmeter, which led to unstable meter readings and unreliable control. These issues stemmed from the separation of oil and water within the meter over its length, as well as fluctuations in the composition of these components, causing unstable densities. 

Fig. 1 – CA Series vs Coriolis Meter Test Setup

Furthermore, instability in the meter's zero and difficulties in cleaning its interior compounded these challenges.

Solutions

Initially, there was thought to use a conventional magnetic flowmeter. However, due to concerns about oil and other residues accumulating, similar to what happened with the Coriolis meter where the electrodes were covered with an insulating coating, it was anticipated that a magmeter would face the same issue. The CA Series, on the other hand, uses non-wetted, capacitively coupled electrodes that are resistant to coating effects.
 
Additionally, its shorter lay length compared to the Coriolis meter makes it better suited to handle potential layer separation between oil and water.

The CA Series flowmeter was tested alongside the Coriolis meter under the following conditions:

Fluid Conductivity:	2.94-3.07 mS/cm
Fluid Composition:	48% oil, 43% water, 9% other
Flow Range:	0-5 tons/hr
Meter Size:	1"
Temperature:	30°C (86 deg F)
Pressure:	MPa (142 psi)
Meter damping:	3 seconds

See Fig. 1 - CA Series vs Coriolis Meter Test Setup. The recorded output from the Coriolis meter fluctuates significantly in recordings. In contrast, the CA Series output remains stable and closely follows the set-point.

NOTES

1. Ensure consistent conductivity measurements of the fluid.
2. The water content and potential water/oil separation can significantly influence fluid conductivity. Assess a fluid sample to determine if two-layer separation occurs immediately or gradually. Immediate separation could render measurement with CA Series impractical.

Key Advantages

• CA Series are impervious to coating problems
• CA Series can measure ultralow conductivity fluids to 0.01 µS/cm
• Stable output with varying levels of oil and impurities
• Short lay length avoids problems due to fluid separation

Fig. 2 – Magnetic Flowmeter CA Series