Wednesday, December 13, 2017

Storage and Process Tanks

industrial sanitary stainless steel process tanks
Industrial process tanks use measurement instruments
to reveal the nature of their contents.
Storage and process tanks are employed throughout a broad range of industrial, research, and commercial applications. The design and construction of the vessels varies widely, but there are a few measurement and control functions common to almost all applications. Whether general purpose or very specialized, a process or facility operator with a tank will need to know…
  • Nature of the contents. What is in the tank.
  • Quantity of material in the tank. This can be expressed as weight, mass, level or volume.
  • Condition of the material in the tank. This can include temperature, pressure, or a range of other specific attributes which may have a bearing on the process or operation for which the material is to be used or applied.
Instrumentation and fixtures of varying styles and types are used to provide information relating to the three areas noted above. A broad range of tank level measurement techniques and instruments are employed to quantify tank contents. Specialized sensors can be used to measure conductivity, pH, and a host of other material aspects.

Industrial storage tanks are used as containers for everything from water to fuels to chemicals. Contents may be pressurized or blanketed with ignition suppressing gases, such as nitrogen. The construction of a process tank must meet requirements for safety and functionality related to its specific use. Well known commercial applications include those in food, beverage, and dairy sectors. Every industrial or commercial use will have standards for physical safety, product safety and quality, as well as requirements for effective integration into whatever system the application presents.

Mixing tanks perform a different function in the control process as opposed to storage tanks. Mix tanks are involved in batching and blending processes. Made of glass, plastic, sturdy rubber, or stainless steel, mixing tanks blend different substances together to create materials for production. The refined mixing process occurs as certain amounts of liquids are funneled into the tank from lines leading to the tank. The tanks may be provided with specialized fixtures or apparatus to facilitate the combining of constituent substances. Depending upon the application, the components may not all be liquid.

The term “tanks”, per se, encompasses practically an entire industry in itself. The variety of sizes, forms, materials, and accessory features is enormous. Share your tank instrumentation and measurement challenges with process measurement specialists, leveraging your own knowledge and experience with their product application expertise to develop an effective solution.

Friday, December 8, 2017

Comprehensive Planning for Heat Trace and Surface Heating Challenges

refinery with workers
Applications for process heating are numerous and varied,
found throughout industrial and commercial settings. 
Keeping process or inventory liquids from freezing, or becoming extremely viscous, can be an important part of a commercial or industrial operation. Freeze damage to equipment, piping, containers or their contents can result in a wide array of consequences, all of them likely to be negative.

Developing an overall plan for freeze protection can be advantageous to attacking each application on an independent basis.
  • Having a common vendor for all freeze protection equipment and supplies can help designers develop a knowledge base about how to meet application challenges with specific products, speeding implementation time. Service techs become familiar with applied products and methods, building their skills and efficiency at installing and maintaining applications throughout the facility.
  • Identify all locations where freeze protection is needed. Develop a baseline of the methods employed and equipment installed to meet the needs of each location. Good records form the basis for good maintenance and the ability to make decisions regarding the operation and performance of each system.
  • When selecting the products or methods to employ for freeze protection, consider the environment in which the hardware will be installed. Will it require protection from physical damage, chemical attack, or extreme weather. Is the installation space considered a hazardous zone, requiring special certifications for the heating equipment?
  • The availability and control of applied heat can also be important. Is there a need for the heating system to deliver highly variable amounts of heat across the range of possible operating scenarios, in order to avoid overheating the process or stored materials? How quickly will the system need to ramp up to the desired operating temperature or respond to changes in an operating process?
These questions, and probably others specifically related to your application, should be part of the consideration for freeze protection applications. Enlisting the cooperation of a process heat specialist can apply leverage to your own process knowledge and experience to develop an effective solution to each challenge.

Check this link and request a copy of the Freeze Protection Planning Guide.

Friday, December 1, 2017

The Possible vs. The Probable

Overhead view of the Arkema plant in Corsby, Texas.
Image from United States Chemcial Safety Board 
Process stakeholders have concerns and responsibilities regarding operational safety, environmental impact, profitability, and more. At almost every level, the risk of loss, damage, or disaster is scrutinized and evaluated. Steps may be taken to prevent or reduce the impact of some negative event. Other risk reduction methods might be put into play to provide relief from losses suffered. Whatever the case, it is safe to say that much industrial effort is invested in predicting a broad range of "what if" scenarios.

The recent events at the Arkema chemical plant in Crosby, Texas bring to light the limitations we, as process operators of any type, may put on our own thinking and actions. Though investment was made, and was ongoing, to improve aspects of the plant, the operation was still brought to a standstill and a fire ensued that brought the involvement of the US Chemical Safety Board. This resulted because natural events that were likely deemed impossible became reality, with insufficient contingency operations in place to handle the situation.

What is important about the event is what we can all learn from it, what we can use to modify and improve our own methods of evaluating risk and implementing protections to prevent loss and damage. Essentially, the plant was overwhelmed by storm induced flooding that was unprecedented. Grid and backup power sources were rendered inoperable and material that required refrigeration to maintain a safe condition no longer was provided with the needed cold storage environment.

arkema chemical plant timeline hurricane harvey US chemical safety board
Timeline of events related to a fire at the Arkema chemical plant in Crosby, TX
Image is from US Chemical Safety Board 
The relationships between an operation and its surrounding environment are not static. The probability of any event occurring is never zero. When probabilities are perceived as being very small, they might be ignored, but low probability events can and do eventually become part of the plant environment. Developing strong contingency plans and incorporating design elements into an operation that account for events that seem impossible, but are actually of very low probability, is a good industrial practice that hardens the process or facility against disaster.

Share and discuss your concerns and plans with process instrumentation and control specialists, leveraging your own knowledge and experience with their resources to develop a better solution.

Friday, November 17, 2017

Gas and Flame Detectors for Industrial Installations

flame detector and fixed gas detector for industrial safety
Flame detector and fixed hazardous gas monitoring units
Image courtesy SMC (Sierra Monitor Corporation)
The demand for increased levels of safety in the workplace continues to expand, with calls for better protection for workers, the plant, the environment, and surrounding communities all weighing on operators to look for ways to reduce risk. Industrial plants, especially those employing hazardous or flammable materials, can have very high risk levels. Reducing the probability of accident or failure can bring a very substantial benefit for long term operation.

Sierra Monitor Corporation manufactures hazardous gas and flame detection equipment for application in commercial and industrial environments. Their sensors and stations enable continuous monitoring of plant conditions and early warning of potentially dangerous conditions. The application possibilities range through every industry.

The document included below provides an overview of the company's products and their potential application. Share your hazardous gas and flame detection monitoring challenges with process measurement specialists, leveraging your own knowledge and experience with their product application expertise to develop a safer solution for your facility.



Friday, November 10, 2017

Differential Pressure Gauge for Level Indication on Liquefied Gas Tanks

differential pressure gauge for cryo tank level indication
A differential pressure gauge can be used to
indicate liquid level in tanks of liquefied gas
Image courtesy Wika
Wika, globally recognized leader and innovator in the design and manufacture of pressure and temperature gauges, provides an enormous number of variants and models of its basic pressure gauge. Many of the gauges are targeted at specific applications, and incorporate a range of design and operational features to accommodate the needs of those applications.

The Cryo Gauge is designed to provide indication of the level of liquid in liquefied gas tanks, but can also serve in some other related applications. For cryo tank applications, several available measuring cells provide operating ranges that cover the most commonly used tank sizes and gas types. An optional manifold with a separate pressure gauge provides connectivity and an indication of working pressure, all in one compact station. Options for analog output, level switches, and remote data transfer are part of the flexible configuration.

More detail on the Cryo Gauge is provided in the datasheet included below. Whatever the application, share your pressure measurement challenges with process measurement experts, leveraging your own knowledge and experience with their product application expertise to develop effective solutions.



Thursday, November 2, 2017

Award Winning Flow Measurement Instrument

ultrasonic flow meter
Flexim F704 Ultrasonic Flow Meter
Image Courtesy Flexim
Flow Control Magazine, which targets solutions for fluid movement, measurement and containment, handed out its annual Innovation Awards recently. Among those receiving honorable mention was Flexim Americas Corporation, for the Fluxus Cryo that provides noninvasive measurement of cryogenic fluids. Special design adaptations prevent ice build up on the measurement apparatus that that can plague other technologies.

Ultrasonic flow measurement offers some distinct advantages over other available methods, with high accuracy, no intrusion into the media, and no moving parts. While the award was specifically for a cryogenic application, Flexim ultrasonic flow measurement instruments are available for an extensive array of applications.

For more information, share your flow measurement requirements and challenges with process instrumentation experts, leveraging your own process knowledge and experience with their product application expertise to develop effective solutions.

Tuesday, October 24, 2017

Simple Tech Drives Reliable Remote Power Unit

remote power unit driven by Stirling engine
The Qnergy remote power unit utilizes a simple
Stirling engine to generate electric power.
Image courtesy Qnergy
M.S. Jacobs and Associates handles the Qnergy line of remote power units, providing electric power to off-grid locations or standing as a backup power source for critical operations. Wherever backup or independent source electric power is needed, Qnergy remote power units can serve as a reliable and economical power source, requiring little to no maintenance.

The technology under the hood in the Qnergy power units is a Stirling engine, adapted and improved by decades of innovation. The engine derives energy input via external combustion, enabling the use of a variety of fuels.
  • Natural gas
  • Propane
  • Ethane
  • Biogas
  • And others
The Stirling engine utilizes a floating piston with no contact points to wear. The system requires no lubrication or regular maintenance, very positive attributes for a remote power unit. Share your project requirements and challenges with application specialists, combining your own knowledge and experience with their product application expertise to develop effective solutions.


Thursday, October 19, 2017

Bag Filter Housings For Liquid Filtration



Filtration is a common processing step in many liquid based industrial operations. Applying the right degree of filtration or particle capture helps assure a predictable level of output quality. Selecting a bag filtration unit should incorporate a number of factors to meet the goal of good performance with a minimized personnel commitment to maintenance.

  • Materials of construction must be compatible with the process liquid, as well as providing resistance to the effects of their surrounding environment.
  • Connection size and type should be adequate for anticipated flow rate and compatible with the connected piping system.
  • Installation location should permit all around access for service, including clearance for opening the unit for filter bag changes.
  • Pressure rating of the housing must meet any applicable requirements of the process, jurisdiction or industry standards.
  • Provide an adequate arrangement to isolate the filtration unit from the fluid system, perhaps with a bypass loop, to allow for in-place access.
The short video illustrates some of the salient features of bag filtration housings that accommodate multiple filter bags. Share your filtration requirements and challenges with processing specialists, leveraging your own processing knowledge and experience with their product application expertise.

Wednesday, October 11, 2017

Pressure and Vacuum Sealed Feedthrough Fittings

multiple versions of vacuum feedthroughs, vacuum chamber feed through fitting
Several versions of vacuum chamber feedthrough fittings.
Image courtesy of Spectite, Inc.
The passage of sensor tubes, electrical conductors, or similar items through the wall of a pressure vessel requires the use of a special fitting that accommodates the physical passage through the vessel wall without compromising the vessel performance. The provision of the right connectors, mounting fitting, and sealant assure simple and effective installation of the feedthrough fitting. Vacuum and pressure feedthroughs are an important part of the physical signal path and the vessel barrier wall, maintaining the integrity of the vessel or chamber containment while facilitating the passage or placement of power, sensors, or other items.

There are countless applications for feedthroughs, resulting in a broad offering of body styles, sealants, connections, and customized arrangements to meet any challenge. Spectite manufactures a broad range of vacuum and pressure feedthroughs, any of which can be customized to meet an application challenge. Share your project requirements with a product specialist, leveraging your own process knowledge and experience with their product application expertise to develop an effective solution.



Wednesday, October 4, 2017

Electronic Pressure Switches

electronic pressure switch NEMA 4 enclosure
Electronic pressure switch in NEMA 4 enclosure.
Image courtesy of Ashcroft
A pressure switch is a device that detects and responds to fluid pressure. Pressure switches use a variety of sensing elements such as diaphragms, bellows, bourdon tubes, pistons or electronic sensors. In all but the electronic sensor versions, the movement of the sensing element, caused by pressure fluctuation, is transferred to a set of electrical contacts to open or close a circuit. Electronic pressure switches utilize a sensor signal and circuitry to control switch activation.

The normal status of a switch is the resting state with stimulation. A pressure switch will be in its normal state when low or minimum pressure is applied. For a pressure switch, normal status is any fluid pressure below the trip threshold of the switch.

One of the earliest and most common designs of pressure switch was the bourdon tube pressure sensor with a mercury switch. When pressure is applied, the bourdon tube flexes enough to tilt the glass bulb of the mercury switch so that the mercury flows over the electrical contacts, thus completing the circuit. the glass bulb tilts far enough to cause the mercury to fall against a pair of electrodes, thus completing an electrical circuit. Many of these pressure switches were sold on steam boilers. While they became a de facto standard, they were sensitive to vibration and breakage of the mercury bulb.

Pressure switches using micro type electrical switches and force-balanced pressure sensors is another common design. The force provided by the pressure-sensing element against a mechanical spring is balanced until one overcomes the other. The tension on the spring may be adjusted to set the tripping point, thus providing an adjustable setpoint.

One of the criteria of any pressure switch is the deadband or (reset pressure differential). This setting determines the amount of pressure change required to re-set the switch to its normal state after it has tripped. The differential pressure setting of a pressure switch should not to be confused with a differential pressure switch, which actually operates on the difference in pressure between two separate pressure input ports.

Electronic pressure switches provide some features which generally are considered advantageous to mechanical designs.
  • No mechanical linkage between sensing element and switch, all electronic.
  • High cycle rates are possible.
  • High levels of accuracy and repeatability.
  • Some models have additional features, analog output, digital display, auxiliary switches, and more.
When selecting pressure switches you must consider the electrical requirements (volts, amps, AC or DC), the area classification (hazardous, non-hazardous, general purpose, water-tight), pressure sensing range, body materials that will be exposed to ambient contaminants, and wetted materials.

Whatever your pressure measurement application, share your challenges with a fluid measurement and control specialist, combining your own knowledge and experience with their product application expertise to develop effective solutions.

Tuesday, September 26, 2017

Thermal Flow Meters

Thermal flow meter for industrial process measurement
Magnetrol TA2 thermal flow meter configured
for insertion mounting.
Image courtesy Magnetrol International 
There are numerous methods and technologies adapted for the measurement of fluid flow, each with its own set of positive attributes and limitations. Understanding the basic operating principles behind each is useful for effective selection of a technology to be applied on a specific application. One technology long employed for continuous fluid flow measurement is thermal dispersion. The operation of a thermal flow meter is as simple as placing a heated object into a moving stream. The amount of heat drawn away, or dispersed, from the heated object is a measurable quantity that is directly proportional to mass flow rate. This is similar in concept to a principle commonly observed in wind chill where someone perceives the temperature to be colder than it actually is at the moment of measurement.

One example of a thermal mass flow meter is a hot wire anemometer, with which air speed is measured via a metal wire charged with an electric current. The faster the air moves around the wire, the more the temperature of the wire will correspondingly drop. The electrical power required to keep the temperature of the wire constant is directly proportional to the flow rate of the air moving past the wire. However, thermal flow meters are inherently used to measure mass air flow and not volumetric air flow.

A common application of thermal flow meters is mass air flow measurement for combustion control, such as in engines and boilers. Maintaining fuel to air ratios in a range resulting in efficient combustion is essential to controlling fuel costs and the level of regulated emissions. Keeping combustion efficient relies on a controller’s ability to modify the combustion air mass flow rate to match the demand for fuel under changing load and input conditions. Thermal dispersion technology can be applied to gases or liquids, making the range of applications very broad.

Typically, thermal mass flow meters used in processing industries will have a flow tube or insertion probe with two temperature sensors, one which is heated and the other which is not. The heated sensor serves as the mass flow sensor, meaning it will cool at a rate directly dependent on mass flow. The purpose of the second temperature sensor is to deliver an accurate measure of fluid temperature. Various processing methods are employed to determine the degree of thermal dispersion, but all are related to the same basic principal.

One of the best applications for thermal mass flow meters is at a particular point of a flow stream, where the flow meter can be inserted or installed to measure a specific amount of fluid being used in the process, such as the amount of gas being sent to a flare. Their design simplicity and ease of production allows thermal flow meters to be very compact. Some are even coupled with built-in throttling mechanisms and other control devices, incorporating measurement and control functions into a single integrated device.

Share your flow measurement requirements and challenges with an instrumentation specialist, combining your own process knowledge and experience with their product application expertise to develop an effective solution.

Friday, September 22, 2017

Motion Detection For Materials Conveying Equipment

Instrument for detecting loss of motion in material conveying system
Loss of motion detector for use in material
conveying systems
Image courtesy Ronan Engineering
Processing equipment in many facilities involves moving materials along a conveyance system from one point to another. Continuous processing requires that the conveyance machinery keeps moving materials through the process. Monitoring movement at selected points along the conveyance can provide immediate notification when machine motion stops.

One motion monitoring unit from Ronan Engineering has been in the market for many years, evidence of its durability and reliability for detecting loss of motion. The X25 has a very simple operating principle. A detector head is located adjacent to a rotating shaft, spoke wheel, screw conveyor, bucket elevator, or other moving part of the equipment. It functions as a pickup with an output signal corresponding to movement of the target. A remotely located housing contains the signal processor with adjustable sensitivity and time interval controls, as well as output relays for signaling loss of movement in the targeted area.

There are a number of adaptations that can be made for installations subject to low rotational speed, high temperature, and other special conditions. The device is simple, rugged, and reliable.

More detail is provided in the data sheet included below. Share your potential applications with process measurement and control specialists. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.



Friday, September 15, 2017

Automatic Self Cleaning Strainer for Fluid Processing

cutaway view of automatic self cleaning strainer
An automatic self-cleaning strainer is suitable for many
applications and reduces manual maintenance.
Strainers and other filtration equipment reduce the burden of targeted unwanted solids in a fluid system. Potentially damaging particulate material is trapped and held for removal from the system. Keeping fluid systems clean helps to maintain long term design performance and potentially extends the operating life of pumps, valves, and other mechanical devices in the system.

Strainers generally consist of a heavy duty housing and a contained screen with controlled opening size designed to disallow the passage of particles exceeding a targeted size. Trapped particulates remain on the screen, or within a shape created by the screen such as a basket (see basket strainer). The continuing collection of solids will eventually impede the free flow of the process fluid, so the strainer must be emptied or cleaned periodically. The frequency of cleaning is a function of the solids content of the incoming fluid and may not necessarily be a regular interval. A simple strainer, to be cleaned, requires temporary shutdown of the flow or bypass of process fluid around the strainer assembly. A duplex strainer consists of twin strainers, usually housed in a common assembly, with a diverter valve that allows the inlet flow to be directed to one of the strainers while closing off the other from the system. This allows for cleaning of one of the strainers while the other is in active service, maintaining continuous fluid flow.
A third solution provides the continuous operation of a duplex strainer, but without the need for manual cleaning. 
An automatic self-cleaning strainer, such as the MCS 500 from Eaton provides uninterrupted operation without a duplex configuration or regular manual cleaning. It's form is essentially a housed strainer with a built-in scraper blade that moves along the inlet surface of the strainer media, moving accumulated solids to a collection chamber at the bottom of the pressure housing. Automatic controls regulate the operation of the scraper and discharge valve on the purge chamber that removes the collected solids from the system. The automatic self-cleaning strainer provides a cost effective time saving solution for the filtration of compatible fluids.

More detail for the MCS 500 is provided below. Share your fluid filtration requirements and challenges with fluid processing specialists. Leverage your own process knowledge and experience with their product application expertise to develop effective solutions.


Tuesday, September 5, 2017

A Little History

26 GHz radar level measurement transmitter
Pulsar® R86 Radar Level Transmitter
One of Magnetrol's recent innovations.
Some companies, through hard work, innovation, and good fortune, manage to stand the test of time and thrive for decades in a competitive environment. The manufacture of process measurement and control equipment and devices is an arena where standing still in the market is not a viable business strategy. Magnetrol has been helping process operators measure and control fluid level and flow for decades. The company recently posted an article on their own blog outlining a little of the company history as illustrated through product innovations. We include an excerpt from the blog below and encourage readers to share their fluid level and flow challenges with application specialists. Leveraging your own process knowledge and experience with their product application expertise to develop effective solutions.

This year marks the 85th anniversary of the founding of Magnetrol®. Since its very beginning, MAGNETROL has been a company focused on level and flow measurement innovation, designing cost-effective, cutting-edge solutions for its customers. In honor of 85 years of success, here’s a look back on some MAGNETROL highlights over the years. 
The Beginning
The history of MAGNETROL dates to 1932 as a Chicago-based manufacturer of boiler systems. The first MAGNETROL level control was born when the founding company, Schaub Systems Service, needed a controller for its boiler systems. Our innovative device was the first of its kind to accurately and safely detect the motion of liquid in boilers and feedwater systems. Soon the MAGNETROL name became synonymous with rock-solid, reliable mechanical buoyancy controls.

Mechanical buoyancy isn’t the only area where MAGNETROL has been a force for innovation. Our devices have changed the radar landscape as well. In 1998, we introduced the Eclipse® Model 705 as the first loop-powered guided wave radar (GWR) transmitter for industrial liquid level applications. The unprecedented reliability and accuracy of the ECLIPSE 705 set a new standard for radar devices.Innovation in Radar
We didn’t stop there, continuing to develop radar technology and adapt it to the needs of our customers. In 1999, MAGNETROL released the first ECLIPSE high-temperature/high-pressure probe, rated to 750 °F (400 °C). We developed an overfill-capable coaxial probe in 2000. And in 2001, we became the first company to incorporate GWR technology into a patented magnetic level indicator chamber, offering true redundant measurement.
In addition to these new developments in GWR, MAGNETROL created many pulse burst and non-contact radar devices for use in challenging process applications. We also secured our core capabilities in electronic technologies, including RF capacitance and ultrasonic.
 Looking Toward the Future
Most recently, MAGNETROL released the Pulsar® Model R86, a groundbreaking new 26GHz non-contact radar featuring a smaller wavelength for smaller antennas and improved 1mm resolution.
We continue to raise the bar for level and flow measurement. Whatever the future of industrial technology, MAGNETROL will be in the thick of it, developing the products that bring customers accuracy, reliability and peace of mind. We are a team of innovators—and innovators are always moving forward.

Wednesday, August 23, 2017

I/P and E/P Transducers

variants of I/P and E/P electronic to pneumatic transducers
I/P and E/P transducers deliver a pneumatic output
proportional to an electronic input signal.
Image courtesy Rotork Instruments - Fairchild
Converting from one signal type to another is a common challenge in process control. When the application calls for conversion from an electrical signal, current or voltage, to a pneumatic signal (pressure), this calls for an I/P or E/P transducer.

I/P and E/P transducers are electro pneumatic devices that convert current or voltage input signals to a linearly proportional output pressure. These transducers are available in a wide array of configurations to accommodate almost any industrial setting or application.

The transducers pictured use, in the pilot stage, electronic closed loop feedback and a piezoceramic actuator flapper nozzle system, controlling the signal pressure of an integral pneumatic volume booster. A control diaphragm and main valve on the volume booster section controls the flow of air at the output in response to the pressure received from the pilot stage. The output pressure of the volume booster is feed into an electronic closed loop feedback arrangement to deliver accurate pressure control.

Applying the transducer is a straight forward operation, involving matching the device input and output signal capabilities with those of the application. More detail is provided in the document included below.

Share your process measurement and control challenges with instrumentation specialists, combining your process expertise with their product knowledge to produce effective solutions.


Tuesday, August 15, 2017

Cloth Heating Jackets

cloth heat jacket installed on valve
Cloth heat jacket insulates and heats regulator valve
with included control module.
Image courtesy of BriskHeat

Industrial heating applications are numerous and varied. Heating requirements can range from freeze protection to precise maintenance of process temperature in piping, equipment, or vessels. Two commonly employed heating sources are electric resistance heaters and plant steam. While each has certain advantages, steam may not always be available or practical. Electric heat offers a number of positive attributes.

  • Ease of design and installation
  • Precise control
  • Uniform heating across surfaces
  • Low maintenance requirement
  • Portability
  • Economical to purchase and install
  • Wide array of shapes, sizes, and configurations
  • Standard and custom products for every application
Cloth heating jackets are one of many electric heater variants. Formed to fit specific valves, fittings, or other items, these reusable heaters are comprised of an exterior of rugged fabric, a layer of thermal insulation, a heating blanket, and an electrical connection point or fitting. Hook and loop fasteners facilitate the unwrapping or opening of the jacket to allow for installation and removal. The surface remains cool to the touch for most applications. Control can be provided by any type of temperature controller, with prewired options available for inclusion with the heating jacket.

More detail is provided in the document included below. Share your process heating requirements with application specialists, combining your own process knowledge and experience with their product application expertise to develop effective solutions.



Tuesday, August 8, 2017

Load Cells for Industrial Applications

One of many styles of load cells
Load cells - One of many styles used throughout
process measurement applications,
Image courtesy of  Minebea-Intec
In industrial application of process measurement and control, principles of the physical sciences are combined with technology and engineering to create devices essential to modern high speed, high accuracy system operation. Years of research, development, and the forward march of humanity’s quest for scientific knowledge and understanding yields packaged devices for process measurement that are easily applied by system designer and operators.

Load cells are the key components applied to weighing component or processed materials in modern industrial operations. Load cells are utilized throughout many industries related to process management, or just simple weighing operations. In application, a load cell can be adapted for measurement of items from the very small to the very large.

In essence, a load cell is a measurement tool which functions as a transducer, predictably converting force into a unit of measurable electrical output. While many types of load cells are available, one popular cell in multiple industries is a strain gauge based cell. Strain gauge cells typically function with an accuracy range between 0.03% and 0.25%. Pneumatically based load cells are ideal for situations requiring intrinsic safety and optimal hygiene. For locations without a power grid, there are even hydraulic load cells, which function without need for a power supply. These different types of load cells follow the same principle of operation: a force acts upon the cell (typically the weight of material or an object) which is then returned as a value. Processing the value yields an indication of weight in engineering units.

For strain gauge cells, deformation is the applied operational principal, where extremely small amounts of deformation, directly related to the stress or strain being applied to the cell, are output as an electrical signal with value proportional to the load applied to the cell. The operating principle allows for development of devices delivering accurate, precise measurements of a wide range of industrial products.

Load cell advantages include their longevity, accuracy, and adaptability to many applications, all of which contribute to their usefulness in so many industries and applications. A common place to find a strain gauge load cell in use is off a causeway on a major highway at a truck weigh station. Through innovation, load cells have been incorporated in an efficient measuring system able to weigh trucks passing through the station, without having each stop. Aircraft can be weighed on platform scales which utilize load cells, and even trains can be weighed by taking advantage of the robust and dependable nature of the transducers.

Thanks to their widespread incorporation and the sequential evolution of technology, load cells are a fantastically useful tool in process measurement and control. Share your process weighing challenges with application experts, combining your own process expertise with their product knowledge to develop an effective solution.


Thursday, July 27, 2017

Thermal Mass Flow Measurement of Tank Blanketing Gas

thermal dispersion mass flow meter insertion type
Insertion style thermal mass flow meter can measure
low flow rates of gas for tank blanketing.
Courtesy Magnetrol
Closed liquid tanks and other vessels contain two substances, liquid and not liquid. The liquid, in this case, is the subject material of a process. The "not liquid" is whatever fills the space not filled by the subject liquid. There are many cases where the process, the subject liquid, and safety are best served by filling the space with a known gas. There may be concerns about ignition of the vapor from the liquid, reactivity of the liquid with oxygen, or a wide range of other issues that call for filling the tank space with a known gas.

Nitrogen is a commonly employed gas for tank blanketing. It is comparatively inexpensive and widely available. It can inhibit combustion by displacing atmospheric oxygen and is not reactive with most industrial process chemicals.

Vessels with rapidly changing levels, or those of very large size, will require larger available flow capacity of blanketing gas to maintain the desired conditions within the tank. There are regulating valves designed specifically for tank blanketing operations. Vents intended for use in the same application are also commercially available.

Monitoring tank liquid level and gas flow are part of best practices for a tank blanketing operation. Confirming that gas flow rate is commensurate with the requirements for current tank level confirms proper operation. Too high a flow rate could indicate a leak or malfunction of a blanketing system component. It may also be useful to totalize gas flow for use in operational planning.

Thermal insertion flow meters are suitable for measuring the wide range of gas flow rates employed in tank blanketing applications. The instruments are available for insertion installation, as shown in the image near the top of this article, or as inline units. Either configuration delivers accurate measurement with no moving parts, a high turndown ratio, and minimal maintenance requirement.

Share your tank blanketing requirements and challenges with process measurement and control specialists, combining your own process knowledge and experience with their product appliction expertise to develop effective solutions.

Wednesday, July 19, 2017

Thermal Mass Flow Meter Questions Answered by Experts

Insertion style thermal mass flowmeter
Thermatel, insertion style thermal mass flow meter
Image courtesy of Magnetrol
Knowledgeable individuals that share expertise and experience with others in their field are a valuable resource, worthy of our attention.

Tom Kemme, from Magnetrol®, expertly fielded some questions about thermal mass flow meters in a recent blog post. Mr. Kemme's responses were so useful and clear that I decided, with all the credit flowing his way, to share them here for those of you that may not closely follow the Magnetrol® Blog.

Will thermal mass flow meters be affected by changes in the composition of gas (i.e. will they require recalibration every time the composition changes)?
Thermal mass flow meters measure a flow rate based on convective heat transfer. Fluid properties are some of the many factors that influence convection. Each gas has unique properties, which is why these flow meters are calibrated for a specific application. You would not want a meter calibrated for an air application placed into a natural gas application without recalibration or some type of field adjustment if applicable.
All gas mixes are not created equal. If you had a gas mix with high hydrogen content, a variation in hydrogen would have a much greater effect than typical variation in natural gas content. Hydrogen has a tendency to create more heat transfer than most gases. For natural gas, it is common to have some slight variation in composition between the calibration of the device and the application itself. However, the effect is minimal for slight changes in methane or ethane at different times of the year. Natural gas fuel flow is one of the most prevalent applications for thermal mass.
Based on our experience, the biggest cause of malfunction in flow meters is improper installation. If you do not install a flow meter per the manufacturer’s recommendation this will greatly influence the performance of the meter. For thermal mass, this includes proper straight run, depth into the pipe (insertion probes) and flow arrow alignment.
Each application presents unique difficulties for every flow meter technology, and each end user has unique needs. There is no exact answer as to when a recalibration would be needed for thermal mass flow, as it is application dependent. You do not always need recalibrations for variation in gas composition.
What role do thermal flow meters play in emissions monitoring applications?
Thermal flow meters are at the forefront in flow measurement for emissions reporting and energy management projects. The energy management arena spans many markets, including some of the largest in the oil & gas and power industries. Some popular applications include monitoring gas fuel flow to a combustion source to report SO2 (sulfur dioxide) emissions, stack (flue) gas flow in power plants as part of a continuous emissions monitoring (CEM) system of NOX (nitrous oxide) and SO2, and flares in a gas field that need to be reported to environmental authorities. These applications prove difficult for many flow meter technologies.
For example, in a flare application most of the time gas is not being flared off, but it needs to be measured in case of an event. The user will want to monitor the low flow of pilot gas keeping the flare lit. This requires a flow meter with a very high turndown with good low flow sensitivity, which is a limitation of some technologies, such as differential pressure flow meters.
Many operators are most concerned with measuring CO2 (carbon dioxide) emissions. However, with thermal flow meters we are increasingly finding applications with the need for methane measurement. Methane is a greenhouse gas that has more than 20 times the global warming potential as CO2. No longer can coalmines or landfills emit this directly to the atmosphere. If not flaring the gas off, the owners are beginning to capture it, treat it, and produce usable natural gas from it. Some facilities that emit landfill gas, or facilities that produce biogas, are involved in carbon credit programs or clean development mechanisms. Similar applications can be found in wastewater treatment plants where customers are reporting digester gas emissions and even capturing this gas to produce electricity and reduce energy costs. Thermal dispersion flow meter technology, such as the MAGNETROL Thermatel® TA2, has become well accepted in all of these markets.
You can easily tap into Magnetrol® expertise to solve your flow measurement challenges. Reach out to a product specialist and combine your process knowledge with their flow measurement expertise to develop effective solutions.

Thermal Dispersion Flow Switches For Pump Protection

thermal dispersion flow switch pump protection
Thermal dispersion flow switches have advantages
when applied for pump protection
Image courtesy Magnetrol
Good practice for installing industrial pumps calls for inclusion of protective devices to assure that the pump is not exposed to conditions beyond its design intent. Monitoring liquid flow is a useful method for determining if a pump is operating within a safe range.

There are numerous methods of verifying flow in piping connected to a  pump. Magnetrol, globally recognized manufacturer of flow and level measurement technologies, offers up their assessment of various pump protection measures and a recommendation for what they consider an advantageous choice for flow measurement in a pump protection application.

Magentrol's white paper is included below, and you can share your flow and level measurement challenges with application experts for help in developing effective solutions.


Friday, July 7, 2017

Corrosion Resistant Flow Meter



There are numerous flow measurement technologies available for application in process measurement. Each technology is represented by a broad array of product variants, each with a set of attributes making it suitable for certain applications.

ICON Process Controls specializes in corrosion resistant industrial fluid handling and process control equipment, offering the most complete line of all plastic instrumentation products supported by the largest inventory in North America. Applications for their corrosion resistant instruments include Municipal and Industrial Water & Wastewater Treatment, Bulk Chemicals, Steel Processing, Metal Finishing, Chemical Dosing Skids, Food & Beverage.

Share your process measurement and control requirements with instrumentation specialists. Combine your own knowledge and experience with their product application expertise for effective solutions.

Monday, June 26, 2017

Hydrostatic Pressure Measurement for Determining Liquid Level

pressure transmitter for mounting to flange on a tank
Pressure transmitters can be used to provide liquid level in
pressurized or open vessels.
Photo courtesy Azbil North America
Pressure measurement is an inferential way to determine the height of a column of liquid in a vessel in process control. The vertical height of the fluid is directly proportional to the pressure at the bottom of the column, meaning the amount of pressure at the bottom of the column, due to gravity, relies on a constant to indicate a measurement. Regardless of whether the vessel is shaped like a funnel, a tube, a rectangle, or a concave polygon, the relationship between the height of the column and the accumulated fluid pressure is constant. Weight density depends on the liquid being measured, but the same method is used to determine the pressure. 

A common method for measuring hydrostatic pressure is a simple gauge. The gauge is installed at the bottom of a vessel containing a column of liquid and returns a measurement in force per unit area units, such as PSI. Gauges can also be calibrated to return measurement in units representing the height of liquid since the linear relationship between the liquid height and the pressure. The particular density of a liquid allows for a calculation of specific gravity, which expresses how dense the liquid is when compared to water. Calculating the level or depth of a column of milk in a food and beverage industry storage vessel requires the hydrostatic pressure and the density of the milk. With these values, along with some constants, the depth of the liquid can be calculated.

The liquid depth measurement can be combined with known dimensions of the holding vessel to calculate the volume of liquid in the container. One measurement is made and combined with a host of constants to determine liquid volume. The density of the liquid must be constant in order for this method to be effective. Density variation would render the hydrostatic pressure measurement unreliable, so the method is best applied to operations where the liquid density is known and constant.

Interestingly, changes in liquid density will have no effect on measurement of liquid mass as opposed to volume as long as the area of the vessel being used to store the liquid remains constant. If a liquid inside a vessel that’s partially full were to experience a temperature increase, resulting in an expansion of volume with correspondingly lower density, the transmitter will be able to still calculate the exact mass of the liquid since the increase in the physical amount of liquid is proportional to a decrease in the liquid’s density. The intersecting relationships between the process variables in hydrostatic pressure measurement demonstrate both the flexibility of process instrumentation and how consistently reliable measurements depend on a number of process related factors. 

Share your process measurement and instrumentation requirements and challenges with professionals that specialize in their proper selection and application. Combining your own process knowledge and experience with their product application expertise will help to develop effective solutions.

Tuesday, June 20, 2017

Commercial and Industrial Process Heating Methods

Special design electric heating element
Electric heating element of special design
Many industrial processes involve the use of heat as a means of increasing the energy content of a process or material. The means used for producing and delivering process heat can be grouped into four general categories.
  • Steam
  • Fuel
  • Electric
  • Hybrid
The technologies rely upon conduction, convection, or radiative heat transfer mechanisms, solely or in combination, to deliver heat to a substance. In practice, lower temperature processes tend to use conduction or convection. Operations employing very high temperature rely primarily on radiative heat transfer. Let's look at each of the four heating methods.

STEAM

Steam based heating systems introduce steam to the process either directly by injection, or indirectly through a heat transfer device. Large quantities of latent heat from steam can be transferred efficiently at a constant temperature, useful for many process heating applications. Steam based systems are predominantly for applications requiring a heat source at or below about 400°F and when low-cost fuel or byproducts for use in generating the steam are accessible. Cogeneration systems (the generation of electric power and useful waste heat in a single process) often use steam as the means to produce electric power and provide heat for additional uses. While steam serves as the medium by which heat energy is moved and delivered to a process or other usage, the actual energy source for the boiler that produces the steam can be one of several fuels, or even electricity.

FUEL

Fuel based process heating systems, through combustion of solid, liquid, or gaseous fuels, produce heat that can be transferred directly or indirectly to a process. Hot combustion gases are either placed in direct contact with the material (direct heating via convection) or routed through tubes or panels that deliver radiant heat and keep combustion gases separate from the material (indirect heating). Examples of fuel-based process heating equipment include furnaces, ovens, red heaters, kilns, melters, and high-temperature generators. The boilers producing steam that was described in the previous section are also an example of a fuel based process heating application.

ELECTRIC

Electric process heating systems also transform materials through direct and indirect means. Electric current can be applied directly to suitable materials, with the electrical resistance of the target material causing it to heat as current flows. Alternatively, high-frequency energy can be inductively coupled to some materials, resulting in indirect heating. Electric based process heating systems are used for heating, drying, curing, melting, and forming. Examples of electrically based process heating technologies include electric arc furnace technology, infrared radiation, induction heating, radio frequency drying, laser heating, and microwave processing.

HYBRID

Hybrid process heating systems utilize a combination of process heating technologies based on different energy sources or heating principles, with a design goal of optimizing energy performance and overall thermal efficiency. For example, a hybrid steam boiler may combine a fuel based boiler with an electric boiler to take advantage of access to low off-peak electricity cost. In an example of a hybrid drying system, electromagnetic energy (e.g., microwave or radio frequency) may be combined with convective hot air to accelerate drying processes; selectively targeting moisture with the penetrating electromagnetic energy can improve the speed, efficiency, and product quality as compared to a drying process based solely on convection, which can be rate limited by the thermal conductivity of the material. Optimizing the heat transfer mechanisms in hybrid systems offers a significant opportunity to reduce energy consumption, increase speed and throughput, and improve product quality.

Many heating applications, depending on scale, available energy source, and other factors may be served using one or more of the means described here. Determining the best heating method and implementation is a key element to a successful project. M.S. Jacobs and Associates specialize in electric heating applications and facets of the industrial production of steam. Share your process and project challenges with them and combine your facilities and process knowledge and experience with their product application expertise to develop effective solutions.

Thursday, June 15, 2017

Wireless Communications Deliver Real Time Process Data From Remote Operating Sites

Oil is where you find it, with many prospecting and production sites located where the communication options taken for granted in developed areas do not exist. Oil is big and serious business, with tremendous sums of money at risk on the prospect of reaping even greater returns. Every business operation, though, is of great importance to the stakeholders. Countless operations in little known industries and endeavors are located beyond the boundaries of modern communications infrastructure.
If you want a data connection, bring your own.
Remote operating sites, whether for oil extraction or other purposes, will often be automated. Some decision making system or individual is responsible for the safe and effective operation of the remote site, or has a use or need for real time data being gathered at the remote site. Radio transmission is a viable, maybe the best, option for delivering real time data from a remote site to a central office.
  • Transmission options for 900 MHz, 2.4 GHz, cellular, and satellite systems are readily available.
  • Equipment operates on low voltage, low power. Suitable for solar or other remote site power source.
  • No special instrumentation needed. Radio transmitting and receiving equipment interfaces directly with analog signals from common industrial process transmitters.
  • No "across the land" cabling needed.
  • Equipment can be configured to resist extreme environmental conditions.
Analynk manufactures transmission and receiving equipment that builds the bridge between remote sites and the home office. From elemental componentry to integrated, ready to run systems, Analynk specializes in wireless communications for industrial process control. Share your wireless process data connection challenges with process measurement and control specialists. Whether an expansive multipoint, or a single point application, application specialists can combine standard or customized products into a practical solution for every application.

Wednesday, June 7, 2017

Zero Bleed Pneumatic Controller for Valve Actuators and Other Process Control Apps



This video shows the components of the BiFold Zero Bleed Pneumatic controller. Called "PICO", this unit was first described in a previous article. Check out the video, as it nicely lays out the various operating components of a complete system. More information is available from product application specialists, with whom you should share your valve control and actuation challenges to get positive and effective solutions.

Thursday, June 1, 2017

Zero Bleed Pneumatic Controller

zero bleed pneumatic positional control
The PICO consists of a single logic control head
and a digital filter booster
Courtesy Bifold - Rotork
The Bifold brand, under the Rotork corporate umbrella, developed a true zero bleed pneumatic position controller for valve actuators. The product, called PICO, consists of a single logic control head and a digital filter booster. The control head unit provides bluetooth communications, ESD monitoring and control, graphic display, integral valve feedback measurement, low power modes, a partial stroke test feature and local control setting switch. The properly installed assembly is suitable for use in hazardous locations.

The new control unit is capable of fulfilling applications employing positional control, on/off and ESD (emergency shutdown) valves. The filter booster allows the small size of the PICO to deliver the flow rate of a substantially larger system of conventional design.
pneumatically actuated control valve with zero bleed controller
The PICO, with control head and filter booster
shown installed on pneumatically actuated valve
Courtesy Rotork - Bifold

The PICO provides a number of operational benefits to pneumatic actuated valve applications. More information is available from product application specialists, with whom you should share your valve control and actuation challenges to get positive and effective solutions.


Monday, May 22, 2017

Two New Products From SVF Flow Controls

rack and pinion actuator and butterfly valves
New products from SVF Flow Controls
SVF Flow Controls, manufacturer of valves and actuators for industrial process control (learn more here), recently released their new rack and pinion actuator, the EZ-Tork™. The line of pneumatic valve actuators features bi-directional stroke adjustment, a continuous position indicator, hard anodized aluminum housing, and universal mounting. The line offers 33 models spanning a broad range of operating torque. Units are available in double acting or spring return variants.

The SL Series of butterfly valves feature direct mounting for electric or pneumatic automation. Manually operated units have a ten position locking handle or gear operator. Epoxy coated ductile iron body, 316 stainless steel disc, and EPDM or BUNA seats enable the application of this valve throughout many industrial settings. Sizes range from 2" to 12".

More detail is available from valve and fluid control specialists. Share your application challenges and combine your own process knowledge with their product application expertise to develop effective solutions.

Monday, May 15, 2017

Prevent Condensation in Your Facility

condensation on glass with ice cubes
Condensation can have a negative impact in
plants, buildings and other and facilities
Condensation, the accumulation of liquid water on a surface through contact with humid air, can be harmless in some settings, an undesirable or even damaging occurrence in others. In situations where condensation is undesirable, taking steps to prevent the conditions that preclude its formation are relatively simple and deliver a good payback.

What is condensation? In general usage, the term refers to the formation of liquid water droplets that occurs when humid air contacts a cooler surface. It is the liquid moisture that accumulates on the exterior of a glass containing a cold drink. Properly, the term condensation names the process of a vapor changing to a liquid. It is the opposite of evaporation. Condensate (note the different word form) is the liquid accumulated through the condensation process. This article is limited to condensate that forms when atmospheric air contacts a cold surface, so the general usage term condensation will be used.

Where can it happen? Water vapor is contained in air when it has sufficient energy to remain in the vaporous state. Remove some of that heat energy and a calculable quantity of the water vapor will no longer be supported, condensing into liquid water. The temperature at which any given quantity of air will start to shed some of its water vapor content is primarily determined by the concentration of water vapor in the air. A higher water vapor content will result in a higher temperature at which the water vapor will begin to condense. In everyday terms, higher relative humidity leads to a higher temperature at which condensation takes place.

What is the range of impact? Condensation appears to us as water that almost magically manifests on a surface. It seems to come right out of thin air.....because that is where it came from. It can form locally or broadly throughout an area. The potential impact of condensation arises from the fact that it is liquid water. Anything that will be damaged by water will be adversely impacted by condensate formation on its surface. This includes rust and corrosion of metals, spotting on material or  object surfaces, the promotion of mold and mildew, and a wide range of other undesirable effects. Accumulated condensate on overhead objects or surfaces can eventually drip onto equipment, materials, and work areas situated below. Puddles of water on a floor can also create a hazard.

Prevention is the best, maybe the only cure.

How to prevent condensate formation?
  • Ventilation - If there is a source of moisture in a space that is elevating the humidity, continually diluting the space moisture content by introducing fresh air with a lower moisture content may be an effective prevention method. Ventilation relies on the fresh air conditions always being sufficient for moisture reduction without creating some other adverse impact on the space. For example, ventilating with outdoor air may be effective throughout only part of the year. Without a reliable source of ventilation air with known conditions, this method may not always deliver the desired results. Ventilation is an active method that requires energy to move the ventilation air. Additional energy may be required to adjust the temperature or moisture conditions of the ventilation air, as well.
  • Insulation - The surfaces where condensation occurs can be isolated from the moist air by insulating materials. This is common with HVAC ductwork and process piping. If done properly, this method is effective. The goal is to create a new surface that does not exhibit the cooler temperatures of the isolated surface. The thickness and reduced thermal conductivity of the insulation material will achieve this. There is also a vapor barrier on the exterior of the insulation that prevents entry of moisture laden air into the insulation material. It is important the the vapor barrier installed as part of the insulating process remain intact and undamaged. Otherwise, water vapor will enter the insulating material and condense, with the potential for a localized failure of the insulating scheme. Insulation is a passive measure that requires no added energy to remain effective.
  • Dehumidification - Outright reduction of moisture contained in the air of an enclosed space will reduce the temperature at which water vapor condenses. Dehumidification machinery is available in a wide range of sizes and performance levels to suit almost any scenario. Though it requires energy to operate, the machinery is generally simple and operates automatically to maintain a space condition that will not support condensation.
  • Heating - Some cases can be most effectively treated using the application of a small amount of heat to the surface where condensation forms. This active method can be very effective when the need is localized. Also, surface heaters can be fabricated that will fit where insulation will not, and the heating assemblies may be more resistant to impact and damage than insulating materials. Proper control of heating equipment will minimize energy consumption.
Implementing an effective plan to combat condensation involves the identification of the conditions that promote its formation in your own facility. Selecting the best prevention plan calls for consideration of costs and reliability of various schemes. Active methods, such as heating or dehumidification, have some capacity for adjustment if conditions change over time. Insulation plans should have sufficient headroom or safety factor in their design to accommodate unforeseen conditions.

Reach out to product application specialists and share your challenges and concerns. Combining your own facilities and process knowledge with their product application expertise will result in effective solutions.