Thursday, December 1, 2016

Toxic Gas and Vapor Detectors - What Can Be Measured

hazardous toxic gas detector explosion proof
Explosion Proof Toxic Gas Detector
Courtesy Dräger
Industrial sites that employ or produce hazardous or toxic gases have a high level of responsibility for protecting workers and the environment from exposure or harm. A significant component of efforts to mitigate the risk posed by toxic gas or vapor is to install instruments capable of detecting the target gases at levels sufficient to provide an alert before, or when, levels reach unacceptable concentrations.

Dräger manufactures gas detectors utilizing electrochemical sensing technology, providing continuous detection of target gases and vapors under a wide range of environmental conditions. The sensors are factory calibrated and ready to use when shipped. The sensor connection is intrinsically safe, so a flame arrestor is not needed. Intelligent self-testing provides predictive maintenance assistance.

There is more to learn about the toxic gas and oxygen sensors from Dräger. The document included below provides a guide to the over 100 toxic gases and vapors detectable by the unit. Share your toxic gas, vapor, and oxygen detection challenges with a product application specialist. The combination of your process knowledge with their product application expertise will produce effective solutions.


Thursday, November 17, 2016

Applying Turbine Flow Meters For Clean Liquids and Gases

turbine flow meter flange connections Hoffer
Turbine Flow Meter
Courtesy Hoffer Flow Controls 
A turbine flow meter provides a volumetric measurement of liquid or gas flow through the use of a vaned rotor (turbine) inserted in the fluid flow path. Fluid movement causes the turbine to rotate at an angular velocity proportional to the flow rate. A pickup senses the passage of the rotor vanes, producing a sine wave electrical signal output which is detected by the unit electronics. The frequency of the signal relates directly to the flow rate.

Generally, a turbine flow meter is applied to measure unidirectional flow. Some turbine flow meters, through the use of two pickups, have the capability to measure flow in both directions.

There are a number of considerations when selecting a turbine flow meter:

  • Material of construction: Numerous material options are available for the housing and internal parts. Proper selection considers media characteristics and cost.
  • Bearing selection: The combination of bearing type and material will likely be selected by the device manufacturer, based upon a comprehensive application information set.
  • Pickup selection: Several pickup options may be available, with the manufacturer making a recommendation that best suits the application parameters.
turbine flow meter installation schematic
Typical Turbine Flow Meter Installation Schematic
Courtesy Hoffer Flow Controls
Here are a few other things to consider about applying turbine flow meters:
  • Turbine flow meters are precision instruments and will not tolerate debris well. An installation should include a strainer configured to trap debris that may damage the instrument of hinder its operation.
  • For longevity, it is advisable to size the flow meter to avoid extended operation near the upper end of its rotational range. Excessive rotational speeds can accelerate wear on bearings.
  • Lower rotor mass will provide more rapid response to changes in flow, allowing use of the device in applications with flow pulsations.
  • Maintain sufficient downstream pressure to prevent flashing or cavitation. This condition will cause the instrument to produce readings higher than the actual flow rate.
  • Sufficient straight pipe length should be installed at the inlet and outlet of the flow meter to provide flow conditioning necessary for accurate readings. In some cases, a flow staightener may be needed on the upstream side.
  • The output signal from the pickup may need amplification or other signal conditioning. Electrically noisy environments or long cable lengths may require special treatment.
Careful consideration of what is necessary for proper operation will pay off with reliable and accurate performance, low maintenance, and a long service life. Share your flow measurement challenges with product application experts, combining your process knowledge with their product application expertise to develop effective solutions.


Wednesday, November 9, 2016

Box-In-Box Coriolis Flow Meter Design Explained



Yokogawa, manufacturer of the Rotomass Coriolis Flow Meter utilizing the patented "box-in-box" design, has produced a short video explaining how their design counteracts some of the environmental and process piping conditions that can negatively impact measurement of fluid flow. On Coriolis type flow instruments, conditions that apply stress to the sensor tube assembly can change the resonant frequency of the assembly, impacting the measured reading. The Yokogawa design employs a means to minimize or eliminate their effect, maintaining accurate measurement of flow in process piping.

Share your flow measurement challenges and requirements with product application specialists, combining your process knowledge with their application expertise to develop effective solutions.

Wednesday, November 2, 2016

Direct Drive Pressure Gauges for the Rugged Industrial Applications

direct drive industrial pressure gauge
Direct Drive Industrial Pressure Gauge
Wika - 3D Instruments
Pressure indication, on location, real time. That is what a dial pressure gauge provides a process operator. Pressure gauges do not require any type of operating power, making them immune to power failures. The Bourdon tube mechanical operator is generally rugged and reliable. They are, however, subject to wear in the linkage that connects the Bourdon tube to the indicator needle over time. Extremes of vibration will also likely impact the longevity of the linkage, leading to premature failure.

3D Instruments, a manufacturer of pressure gauges and related products for industrial, commercial, and scientific applications, has developed a direct drive pressure gauge intended for use in the most rugged and demanding applications. The direct drive pressure gauges have only one working part, a helically-wound Bourdon tube made of Inconel® X-750, a flexible material that prevents the coil from losing its shape and ensures accuracy. The indicating needle is directly connected to the Bourdon tube, eliminating linkage parts. This innovation, while maintaining the benefits of some of the oldest pressure measurement technology, adds improvements in overpressure protection, burst protection, wear resistance, and life cycle cost.

A short video, included below, highlights and illustrates how the direct drive system works. Reach out to a process measurement product specialist for more detail, or solutions to any of your measurement and control challenges.

Wednesday, October 26, 2016

Industrial Process Gas Chromatograph With Parallel Processing

industrial process gas chromatograph parallel processing
GC8000 Process Gas Chromatograph
Yokogawa
Gas chromatography is a common analysis tool employed in many areas of the process control industry, including oil and gas, pharmaceutical, chemical, and others. Yokogawa Corporation of America developed instrumentation to provide top tier GC performance with their GC8000 Process Gas Chromatograph for use in oil and gas, and other industrial applications.

In addition to the ruggedness and reliability for which Yokogawa gas chromatographs are well known, the GC8000 brings a number of innovations and improvements to the company’s process gas chromatography product offering.
  • Color touchscreen HMI for easy operation
  • Advanced predictive diagnostics and software functions monitor key performance indicators during each analysis to verify analyzer is operating within proper tolerances.
  • Parallel chromatography enabled through the use of GC Modules provided as part of the GC8000. Virtual GCs can be set up inside a single GC with GC Modules to measure multiple streams simultaneously.
The graphics below expand on this overview of the GC8000 Process Gas Chromatograph, the culmination of Yokogawa’s 55 years of experience in the field. For more detailed information, or to discuss your application specifics, contact a product specialist.


Tuesday, October 18, 2016

Process Analyitcal Measurement - Moisture Control In Sample Gas

instrument air sample gas moisture control filter
Sample Gas Dryer
Perma Pure
Sample gas used for analysis in process control operations will often need some conditioning in order to accommodate the input needs of the analyzer. A common requirement is to maintain a certain moisture content in the gas sample, requiring either addition or removal of moisture from the sample stream.

It is advantageous, even necessary, that any conditioning done to the sample gas have no impact on the component(s) subject to analysis. One technology provides for specific removal or addition of moisture (water) in a simple fashion, with no impact on other sample constituents.

Perma Pure gas sample dryers and humidifiers use Nafion® tubing, with a selectively permeable membrane that permits only the passage of water molecules. By controlling relative vapor pressure around the exterior of the tube, moisture can be drawn from, or added to, the sample gas stream. The simple device employs no moving parts and the vapor pressure differential is easily achieved using shop instrument air or other sources readily available.

Share your gas analysis challenges and requirements with product application experts, combining your process knowledge with their product expertise to develop effective solutions.
diagram of sample gas processing connections and parts


Thursday, October 13, 2016

Accurate Measurement of Low Flow In Compressed Air Systems

Plant operators are well aware of the cost associated with continuous delivery of compressed air, a useful medium utilized as an energy source. Large or multiple compressors consume considerable amounts of electric power maintaining system pressure and flow requirements. With extensive piping and countless fittings, there are many potential points of leakage. Scheduling of various production operations can vary the demand for compressed air significantly. Getting control of your compressed air system and reducing operating cost is a noble goal. One of the primary tools needed to manage energy costs will be accurate and reliable flow measurement equipment. Here are some characteristics of flow measurement instrumentation that should prove advantageous:
Portable ultrasonic flow meter with clamp on transducer
Portable Ultrasonic Flow Measurement Instrument
Flexim

  • Non-invasive measurement from the outer pipe wall that does not add potential leak sources or pressure drop.
  • Availability in fixed or portable configuration.
  • Highly accurate, with paired temperature compensated traceable calibrated transducers
  • Installed without disturbance to piping.
  • Bidirectional measurement
  • Rugged instrument design suitable for any kind of industrial environment
Ultrasonic flow measurement technology can provide all of these characteristics, providing information that enables the operator to make fact based decisions about system design, management, and maintenance. Learn more about how ultrasonic flow meters specifically configured for compressed air system application can help you start reducing your operating cost and developing a higher level of control over your compressed air system. Share your process challenges with a product specialist and work together to build the best solution.