Vortex Flow Measurement for Gas, Liquid and Steam Applications

When it comes to measuring flow, you have many choices among technologies. For gas, liquid, and steam flow metering applications, vortex technology is an option.

If you’re unfamiliar with how Vortex flow meters work, Wikipedia describes it:

Another method of flow measurement involves placing a bluff body (called a shedder bar) in the path of the fluid. As the fluid passes this bar, disturbances in the flow called vortices are created. The vortices trail behind the cylinder, alternatively from each side of the bluff body. This vortex trail is called the Von Kármán vortex street after von Kármán’s 1912 mathematical description of the phenomenon. The frequency at which these vortices alternate sides is essentially proportional to the flow rate of the fluid. Inside, atop, or downstream of the shedder bar is a sensor for measuring the frequency of the vortex shedding. This sensor is often a piezoelectric crystal, which produces a small, but measurable, voltage pulse every time a vortex is created. Since the frequency of such a voltage pulse is also proportional to the fluid velocity, a volumetric flow rate is calculated using the cross sectional area of the flow meter. The frequency is measured and the flow rate is calculated by the flowmeter electronics using the equation f=SV/L where f is the frequency of the vortices, L the characteristic length of the bluff body, V is the velocity of the flow over the bluff body, and S is the Strouhal number, which is essentially a constant for a given body shape within its operating limits.

Robert Zaun Marketing Director

Robert Zaun
Marketing Director

In this short 2:53 YouTube video, The Rosemount 8600 Utility Vortex, Emerson’s Robert Zaun explains how the Rosemount 8600 Utility Vortex flowmeter is optimized for general purpose gas, liquid, and steam flowmetering applications—where the fluids need to be homogeneous and single-phase.

He opens highlighted some of the strengths in vortex flow measurement technology such as no moving parts, excellent rangeability (“the ratio of the maximum full scale range to the minimum full scale range of the flowmeter”) and a 30-to-1 turndown ratio. Continue Reading

Extending Measurement Device Stability to 15 Years

One of the benefits of advancing technologies can be increased reliability. For measurement devices in the processing industries, these technology improvements can mean increased operations and maintenance productivity through extended calibration intervals, improved measurement repeatability, and overall improved measurement stability.

Michael Olivier Product Marketing Manager

Michael Olivier
Product Marketing Manager

Emerson’s Michael Olivier shared with me improvements that have been made to the Rosemount 3051S Series of measurement instrumentation. This series of measurement devices was first introduced in 2001.

Rosemount 3051S Wireless Transmitter with Rosemount 306 In-Line Manifold

Rosemount 3051S Wireless Transmitter with Rosemount 306 In-Line Manifold

The 3051S Series encompasses pressure, differential pressure (DP) level, DP flow, and Multivariable (differential pressure, static pressure, and process temperature measurements along with mass and energy flow) transmitters that can communicate via digital 4-20mA HART protocol, IEC 62591 WirelessHART, and Foundation fieldbus.

Michael noted that stability has been extended to 15 years as well as the limited warranty due to optimizations in the SuperModule sensors within these devices. These sensors are all-welded hermetic stainless steel (SST) design and provide up to ±0.025% accuracy and 200:1 rangedown (ratio between the sensor upper range limit and the calibrated span) and up to ±0.04% of reading and 14:1 flow turndown. Continue Reading

Solving Reactor Water Drum Level Problems

Mark Brewer Senior Consultant

Mark Brewer
Senior Consultant

Author: Mark Brewer

I was asked by the engineers at a chemical manufacturing site here in the United Kingdom if I could have a quick look at a level control problem in a reactor coolant water drum. They have 2 very large reactors that generate a lot of waste heat that is removed from the reactors by generating steam in cooling coils.

The two reactors share a single water drum that provides water to the steam generating coils. If one reactor comes off line because of a shutdown system trip, the level in the drum rapidly falls to the point where the second reactor may trip.

This behaviour is very strange because the water is not leaving the system, yet the drum level rapidly falls. We think that because the source of heat is removed from the reactor steam coils, any steam in the reactor coils quickly condenses and the volume is replaced with liquid water from the coolant drum, causing a fall in level. Continue Reading

Hearing Machinery Reliability Issues

 Business Development Manager

Mark Granger
Business Development Manager

Sometimes your ears can identify problems with rotating machinery before investigate any further. In this 5:11 YouTube video, Audio with Parameter Alarms and Trends, Emerson’s Mark Granger shows how, in addition to providing immediate colored parameter alarms bar charts and trends up to two years’ duration, the CSI 2140 Machinery Health Analyzer also lets you listen to vibration as it is being collected via filters that isolate various frequency ranges. As the data is being collected, advanced signal processing provides alarm notifications on the portable vibration analyzer in real time.

Using Bluetooth speakers that are rated for the hazardous area location in which the rotating equipment operates, Mark shows how the vibration signals can be sent to the speakers. The signals can be filtered to remove ranges to frequencies to listen for specific problems. Continue Reading

Impacting Technology Advancements at Emerson Exchange Conference

Inspiring-IngenuityThe Emerson Global Users Exchange conference is the preeminent conference for knowledge exchange for process automation and instrumentation professionals using Emerson technologies and working with Emerson experts. The next conference is October 6-10 in Orlando, Florida.

I wanted to mention this since this Friday, August 15 is the deadline for early registration to save $US 200 on your conference fees.

If you’re an Emerson Exchange 365 community participant, make sure you check out the Dinner with an Expert opportunity to connect with your peers and fellow experts.

Human Centered Design approach

The Emerson Exchange conference is also an opportunity to have your voice impact the development of technologies through a human centered design approach. Some of the product brands which will be seeking your input include Rosemount, Fisher, Micro Motion, Reliability Solutions, Daniel and DeltaV.

The Human Centered Design (HCD) team will be conducting usability testing during these hours at the conference: Continue Reading