Sunday, January 21, 2018

Asset Condition Monitoring for Major Equipment

turbine blades
Asset and equipment monitoring promotes the maximizing
of productivity by reducing downtime.
Minimizing machine or system downtime, for whatever cause, is a common productivity and financial goal of industrial processing of all types. Lost production time can never be recouped, and unplanned equipment outages can cost millions. There is real benefit to be had from monitoring operational aspects of machinery and systems in real time.

Asset condition monitoring, as the name implies, is the process of continually monitoring a machine or piece of equipment with the intent to alert operators to anomalies in machine function. Data gathered can also be used to define a normal operating envelope and show trends that may indicate a need for service. The goal, ultimately, is to repair, adjust or maintain prior to and avoiding outright failure. Key indicators of failing equipment can be changing values in vibration, noise or temperature measurements. Monitoring these and other variables, some derived at very localized and specific points, provides key indicators of the condition of the machine. By evaluating trends in the data, intelligent systems can provide health information about the equipment and assist in the early detection of possible faults or failures.

Implementation of asset condition monitoring is benefiting manufacturing plants and process industries such as chemical, petrochemical, pulp and paper, power generation, wind turbine, and oil and gas. Not only can it save money from protecting against unplanned outages, but condition monitoring also improves productivity, quality and profitability.

GE's Bently Nevada 3500 Monitoring System provides continuous, online monitoring suitable for machinery protection and asset condition monitoring applications. It is the company's most capable and flexible system, with a traditional rack-based design. The useful features of the system are numerous, and it delivers advantages not provided in other systems. Share your major asset monitoring challenges and plans with a systems specialist, and leverage your own knowledge and experience with their product application expertise to implement an effective solution.


Friday, January 19, 2018

Process Instrumentation Selection Tool

company logo Yokogawa
Yokogawa's Process Instrumentation Selection
Tool saves time when searching for the right
process measurement instrument.
Image courtesy Yokogawa
Yokogawa Corporation of America, an industry recognized source for innovative process measurement and control products, has made available an easy to use product selection tool for those navigating through the company's extensive product offering. The Product Finder is a great time saver that enables a user to quickly locate product and technical information on Yokogawa products that meet the user's selected criteria.

Let's step through a quick example. You will see how this quick and easy to use tool saves time by navigating quickly to the website pages detailing products meeting your requirements.

The Product Finder is accessible through a number of links throughout Yokogawa's network of Reps. Clicking the link lands you on the start page of the Product Finder. For this example, I am going to search for a flow meter with the following characteristics:
  • Mass flow measurement 
  • Non-conductive liquid
  • Accuracy of 1%
  • Flow measurement device must have an integral transmitter
  • Tri-clamp connections

Above, I declared my location as United States. The next step, shown below, is to select "Flow" as the measurement parameter. You will see in the drop down menu that there are many measurement elements that can be selected, with Yokogawa products for each.

My selection of "Flow" returns a list of all the company's flow measurement devices, of which there are many (this cropped screenshot, shown below, only shows four, but there were many more) . This is where the selector really helps you. Instead of examining several or many different models, the user can focus the search by adding more product characteristics. You can see the list of prompting questions on the left side of the page. Answering these will narrow the search results to the show only the products meeting all the criteria specified by the user.


The next image (below) shows selections of all my sample product attributes entered on the left column. Note that there is now only a single product that matches all of my sample criteria. The whole process took less than two minutes. By clicking on the "View More Details" button below the product image, I gain access to all of the available technical, support, and product data for my selected flow measurement device.


The process instrumentation experts at Classic Controls are available to provide additional help in meeting your process measurement challenges in Florida, Puerto Rico and the Caribbean. Combine their product knowledge and expertise with your process know-how for the best solutions.

Friday, January 12, 2018

Lightning Protection Techniques

lightning strike on dark night
Facilities of many types need protection from the
harmful impact of lightning strikes.
The forces of nature often prove to be resistant to a full understanding by the likes of humanity. Lightning simultaneously frightens and fascinates us, and it seems to be less predictable in its touchdown points than we would like it to be. Lightning strikes constitute extreme releases of energy. A direct hit to your facility or equipment has a high probability of rendering it unusable. The pathways of the destructive energy can be diffuse and unpredictable.

Prevention, by diverting the energy away from where it will do harm, is generally considered to be the best protective path for industrial and commercial facilities. In a previous post, we shared a comparison of several lightning protection techniques. The report is included below for review.

Dehn Inc. has been providing lightning protection and related equipment since 1910. The company provides solutions in the field of surge protection, lightning protection/earthing and safety equipment for many industries including, water wastewater plants, buildings and systems, industrial plants, energy supply, oil and gas industry, security systems, chemical & pharmaceutical industry, transportation systems. Their success in the field today is based upon decades of experience designing and producing protective installations and gear for facilities of many types and in many locations.

Share your lightning protection challenge with system specialists, and leverage your own knowledge and experience with their application expertise to develop an effective lightning protection plan.



Friday, January 5, 2018

Explanation of Overpressure and Overpressure Protection for Yokogawa DPharp EJX/EJA-E Series Transmitters



This video demonstrates what overpressure is, how it effects pressure transmitters, and the mechanism Yokogawa deploys for overpressure protection for on their DPharp EJX/EJA-E series.

For more information on Yokogawa in Florida, Puerto Rico, or the Caribbean contact Classic Controls. Share your process measurement and control challenges and leverage your own knowledge and experience with their product application expertise.

Wednesday, December 13, 2017

Methods of Continuous Level Measurement in Industrial Process Control

Fuel tanks at refinery
Information about liquid level in a tank is an integral part
of successful process operation and safety.
Many industrial processes require the accurate measurement of fluid or solid (powder, granule, etc.) height within a vessel. Some process vessels hold a stratified combination of fluids, naturally separated into different layers by virtue of differing densities, where the height of the interface point between liquid layers is of interest.

A wide variety of technologies exist to measure the level of substances in a vessel, each exploiting a different principle of physics. This chapter explores the major level-measurement technologies in current use.

Level gauges

Level gauges are perhaps the simplest indicating instrument for liquid level in a vessel. They are often found in industrial level-measurement applications, even when another level-measuring instrument is present, to serve as a direct indicator for an operator to monitor in case there is doubt about the accuracy of the other instrument.

Float

Perhaps the simplest form of solid or liquid level measurement is with a float: a device that rides on the surface of the fluid or solid within the storage vessel. The float itself must be of substantially lesser density than the substance of interest, and it must not corrode or otherwise react with the substance.

Hydrostatic pressure

A vertical column of fluid generates a pressure at the bottom of the column owing to the action of gravity on that fluid. The greater the vertical height of the fluid, the greater the pressure, all other factors being equal. This principle allows us to infer the level (height) of liquid in a vessel by pressure measurement.

Displacement

Displacer level instruments exploit Archimedes’ Principle to detect liquid level by continuously measuring the weight of an object (called the displacer) immersed in the process liquid. As liquid level increases, the displacer experiences a greater buoyant force, making it appear lighter to the sensing instrument, which interprets the loss of weight as an increase in level and transmits a proportional output signal.

Echo

A completely different way of measuring liquid level in vessels is to bounce a traveling wave off the surface of the liquid – typically from a location at the top of the vessel – using the time-of-flight for the waves as an indicator of distance, and therefore an indicator of liquid height inside the vessel. Echo-based level instruments enjoy the distinct advantage of immunity to changes in liquid density, a factor crucial to the accurate calibration of hydrostatic and displacement level instruments. In this regard, they are quite comparable with float-based level measurement systems. Liquid-liquid interfaces may also be measured with some types of echo-based level instruments, most commonly guided-wave radar. The single most important factor to the accuracy of any echo-based level instrument is the speed at which the wave travels en route to the liquid surface and back. This wave propagation speed is as fundamental to the accuracy of an echo instrument as liquid density is to the accuracy of a hydrostatic or displacer instrument.

Weight

Weight-based level instruments sense process level in a vessel by directly measuring the weight of the vessel. If the vessel’s empty weight (tare weight) is known, process weight becomes a simple calculation of total weight minus tare weight. Obviously, weight-based level sensors can measure both liquid and solid materials, and they have the benefit of providing inherently linear mass storage measurement. Load cells (strain gauges bonded to a steel element of precisely known modulus) are typically the primary sensing element of choice for detecting vessel weight. As the vessel’s weight changes, the load cells compress or relax on a microscopic scale, causing the strain gauges inside to change resistance. These small changes in electrical resistance become a direct indication of vessel weight.

Capacitance

Capacitive level instruments measure electrical capacitance of a conductive rod inserted vertically into a process vessel. As process level increases, capacitance increases between the rod and the vessel walls, causing the instrument to output a greater signal. Capacitive level probes come in two basic varieties: one for conductive liquids and one for non-conductive liquids. If the liquid in the vessel is conductive, it cannot be used as the dielectric (insulating) medium of a capacitor. Consequently, capacitive level probes designed for conductive liquids are coated with plastic or some other dielectric substance, so the metal probe forms one plate of the capacitor and the conductive liquid forms the other.

Radiation

Certain types of nuclear radiation easily penetrate the walls of industrial vessels, but are attenuated by traveling through the bulk of material stored within those vessels. By placing a radioactive source on one side of the vessel and measuring the radiation reaching the other side of the vessel, an approximate indication of level within that vessel may be obtained. Other types of radiation are scattered by process material in vessels, which means the level of process material may be sensed by sending radiation into the vessel through one wall and measuring back-scattered radiation returning through the same wall.

Laser

Lasers can be employed essentially as distance measuring instruments, emitting a beam from above the target material and measuring the elapsed time for the emission to return as a reflection from its surface. With no moving parts, this can be an attractive technology for some applications.

The sales and application engineers at Classic Controls are experts in industrial level control. Feel free to contact them with your level measurement and control challenges. Combine your own process knowledge and experience with their product application expertise to develop an effective solution.

Thursday, December 7, 2017

Match Temperature Sensor Configuration to the Application for Best Results

heat tracing temperature sensor
Special construction features can better adapt a temperature
sensor to measuring process conditions.
Image courtesy Pyromation
There are more temperature controlled operations than any of us could count in a lifetime, each with a set of signature performance requirements and design challenges. Matching the means of temperature measurement, the control loop characteristics, and heat delivery method to the application are essential to achieving successful operation.

Step one is to measure the process temperature. This sounds simple until you start researching products and technologies for measuring temperature. Like the temperature controlled operations mentioned previously, they are numerous. To filter the possible candidates for temperature sensing devices, consider these aspects of your application and how well a particular sensor may fulfill your requirement.
  • Response Time - How rapidly the sensor will detect a change in process temperature is a function of how the sensor is constructed and how it is installed. Most temperature sensors are enclosed or encapsulated to provide protection for the somewhat vulnerable sensing element. Greater mass surrounding the sensing element, or a shape that inhibits heat transfer from the process to the sensor, will slow sensor response. Whether the slower response time will adversely impact process operation needs to be considered. More consideration is due to the manner in which the temperature sensor assembly is installed. Not all applications involve a fluid in which the sensor assembly can be conveniently immersed, and even these applications benefit from careful sensor placement.
  • Accuracy - Know what your process needs to be effective. Greater levels of accuracy will generally cost more, possibly require more care and attention to assure the accuracy is maintained. Accuracy is mostly related to the type of sensor, be it RTD, thermocouple, or another type.
  • Sensitivity - Related to the construction, installation, and type of sensor, think of sensitivity as the smallest step change in process temperature that the sensor will reliably report. The needs of the process should dictate the level of sensitivity specified for the temperature sensor assembly.
Take a simple application as an illustration. Heat tracing of piping systems is a common function throughout commercial and industrial settings experiencing periods of cold weather. Electric heat trace installations benefit from having some sort of control over the energy input. This control prevents excessive heating of the piping or applying heat when none is required, a substantial energy saving effort. A temperature sensor can be installed beneath the piping's insulation layer, strapped to the pipe outer surface. A specially designed sensor assembly can improve the performance of the sensor and the entire heat trace control system by enhancing the response time of the temperature sensor. A right angled sheath permits insertion of the sensor beneath the piping insulation while orienting the connection head upright. A surface pad at the tip of the sheath increases the surface contact with the pipe to provide faster sensor response. The surface pad is a metal fixture welded to the sensing end of the temperature sensor assembly. It can be flat, for surface temperature measurements, or angled for installation on a curved surface, like a pipe. The increased surface contact achieved with the surface pad promotes the conduction of heat to the sensor element from the heated pipe in our illustration. This serves to reduce and improve the response time of the sensor. Adding some thermally conductive paste between the pad and the pipe surface can further enhance the performance. While the illustration is simple, the concepts apply across a broad range of potential applications that do not allow immersion of the temperature assembly in a fluid.

A simple modification or addition of an option to a standard sensor assembly can deliver substantially improved measurement results in many cases. Share your temperature measurement requirements and challenges with a process measurement specialist. Leverage your own process knowledge and experience with their product application expertise.

Sunday, December 3, 2017

Controller Reduces Standby Cycling to Conserve Energy

gas fired boilers in boiler room
Improved control can reduce dry firing of boilers,
with substantial energy savings.
Heating of commercial and institutional buildings presents a case where there are energy savings available through the application of an advanced control element able to substantially reduce boiler operation time.

Building owners, boiler engineers, operators and other stakeholders will benefit from this simple and understandable video explanation of some of the inefficiencies associated with boiler operation, and how incorporating an additional control element can minimize boiler dry firing (also called standby cycling). Boiler operation costs can be reduced between 10% and 25%, with a commensurate reduction in carbon footprint, by including the Fireye NXM2G control in the boiler control system.

Watch the video. It's just a few minutes and explains the source of the inefficiency, as well as the solution, in a manner understandable to everyone. More information is available from a combustion product specialist, who can help evaluate the efficiency of your current system or assist with incorporating the latest energy saving features and design into a new installation.