For many process plants, there are three distinct tasks with respect to their control, instrumentation and information systems -- otherwise known as the automation system. The first task category is operations. and maintenance. The plant must be kept up and running with minimal downtime, with maintenance, performed as needed.
The second task includes continuous improvements. The existing automation system must be made to increase throughput, reduce downtime, cut energy costs, improve quality and make other enhancements to the production processes. These improvements are necessary to stay competitive in worldwide markets, and firms that neglect this task will fall hopelessly behind.
Third, capital projects must be planned and executed for a variety of reasons, from adding capacity to regulatory compliance to changing the range of products produced. In many process plants, operations and maintenance tasks can consume all the available automation professional man-hours from on-site staff, leaving little or no time for continuous improvements and capital projects. In the worst cases, many plants find it difficult to recruit and maintain even the minimal staffing required for operations and maintenance.
There are two possible approaches to address these staffing issues. The first is to add more permanent staff at the plant level, and the second is to seek assistance from an outside service provider such as a systems integrator -- also known as staff augmentation or outsourcing. Adding permanent staff can be problematic at many process plants for a number of reasons as explained below.
As detailed in a recent Control magazine cover story, demand for experienced automation personnel relative to supply is at an all-time high by many indicators. A quote from the article illustrates the point.
"The demand for process automation professionals is high, and the talent pool is small and shrinking," said Alan Carty, president of recruiting firm Automationtechies in Minneapolis. "Systems integrators, end users and process control product manufacturers are all seeking these people. I've been recruiting for 12 years, and I feel that current demand relative to supply is at an all-time peak."
Exacerbating the situation, many process plant managers have trouble recruiting workers to their. specific locales, which are almost always far from the urban areas favored by many automation, professionals, particularly recent graduates.
Another significant issue primarily affects staffing for plant automation operations and maintenance positions, and that's the requirement for 24/7/365 support. When faced with the choice between working regular hours versus being on-call around the clock -- including weekends and holidays - many automation professionals, opt for the former.
Even if these problems are overcome with sufficient staffing for operations and maintenance, providing sufficient personnel for continuous improvement and capital projects remains an issue.
This task in particular often requires specialized skills that existing plant operations and maintenance staff may not possess. Furthermore, many continuous improvement projects and larger capital projects often require relatively high staffing levels for implementation, then much lower staffing levels for ongoing operations and maintenance.
An Objective Look at the Roles of Cesium-137 and Cobalt-60 in Nuclear Measurement Systems for Industrial Processes
Level and density measurements in process control are performed by a number of technologies. When the process temperature, pressure, or chemistry is an issue, then nuclear measurement systems have the advantage. These are non-invasive to the vessel and unaffected by the process pressures and chemistries.
Overall, a nuclear measurement system used for process control consists of a gamma energy emitter and detector. An emitter is placed on one side of a vessel to broadcast a beam of energy to the opposite side of the vessel. The detector is placed in the beam on the opposite side of the vessel. The detector will scintillate in the presence of gamma energy and register counts proportional to the field strength. When the process value (level or specific gravity) is low, the detector will register a high number of counts since less gamma energy is blocked by the process material. When the process value is high, more of the gamma energy is blocked which leads to fewer counts.
The two most common gamma emitters used for level and density process measurements are isotopes of cobalt and cesium. The goal of this article is an objective comparison of the roles of cesium-137 and cobalt-60 in process measurement. This will be accomplished by reviewing the properties of the two materials and then comparing the use of the materials in process measurement.
Updated government regulations created a need for a major international oil and gas company to install a direct, real-time communications link at a platform located off the coast of Louisiana in the Gulf of Mexico.
ENI Petroleum is an Italian multinational oil and gas company with around 78,400 employees at sites in 77 countries. ENI operates in the oil and gas, electricity generation and sales, petrochemicals, oil field services construction and engineering industries. It has oil and natural gas production of almost two million barrels per day, with exploration and production efforts at sites throughout North American, Africa and Asia.
One of these production locations is an oil well platform called the "Devil's Tower" that is located just off the coast of Louisiana in the Mississippi Canyon region of the Gulf of Mexico. The platform rises 5,610 ft. above the sea bed. Until 2010, it was the deepest production truss spar in the world. Drill ships perform periodic operations within close proximity to subsea pipelines that transport oil and gas to and from the production platform.
In this white paper, you will learn how a new data concentrator system allowed the control room and drill ships to communicate at a distance of more than 100 km, providing security in case of an incident while avoiding costly shutdowns.
Jim McConahay, P.E., senior field applications engineer, Moore Industries and Richard Conway, facility engineer, ENI Petroleum
Water is a key element to life. It plays an important role in the world economy, as it functions as a solvent for a variety of chemical substances. 71% of the Earth's surface is covered with water and 97% of that water is in oceans and saline. Only 3% of the earths water is fresh and can be found in the polar caps, glaciers, ground aquifers, lakes, swamps and rivers. In parts of the world where there is limited or no access to fresh water, desalination is being used to convert saline water to drinking water. To manage resources and the flow of water, modern electrical pumps and control systems are employed. Water chemical compatibility and electrical interference are two major challenges for the control systems. Let's ook at two major sources of fresh water and the issues that can limit the performance of the control system.
Differential pressure (dP) sensors with electronic signal processing are increasing being used to monitor flow, filter condition and level. Since these devices offer linear and accurate output, they are also replacing the differential pressure switch that only support on-off condition and useless for closed loop control system. These dPs are often configured with expensive valves and fluid filled remote seals for added protection against corrosive media, radiation and/or extreme media temperature ranges when operating in demanding environments. In cold ambient environment specially operating in temperatures below -4 deg F (-20 deg C), the sensor need to be heated either by trace heater or within a heated enclosure to maintain the operation of the dP sensor. In addition to being expensive, these valves and seals tend to be bulky and require time to install and maintain. In many critical applications such as food and pharmaceuticals, filled fluids are a serious concern due to process contamination. In gaseous systems such as hydrogen and oxygen and semiconductor applications, fluid filled sensors are being banned since the leakage of fluid into the process could lead to an explosion and serious safety issues.
A new series of LVDT (linear variable differential transformer) based oil-less dP sensor with dual channel ASIC (applications specific integrated circuit) have been developed that can operate in a wide range of corrosive materials, radiation and temperature without any oil filling and bulky sealing systems. By encapsulating LVDT proven technology with digital compensation, the pressure sensors combine the benefits of friction-free operation, environmental robustness and unlimited mechanical life. By selecting the diaphragm thickness and material properties, Table 1 show the dP ranges that can be produced using the LVDT technology.
There are over two hundred pressure sensor suppliers around the world, offering products from a few dollars to thousands of dollars. A purchaser or engineer unfamiliar with pressure sensors can become overwhelmed with the price range, quality and options. The first step is to understand his/her application from the media being measured, to the desired electrical output for indication or control. The following is a guide through a variety of options to make a prudent decision.
Media is the most important item when selecting a pressure sensor for an application. Most sensor suppliers only sell sensors that are rated for benign environments such as clean, dry air. The next tier of suppliers will sell products that will handle mild environments through to difficult/corrosive environments. Clean water, steam, some forms of hydraulic oils and Freon can be considered mild environments. Difficult media tends to be corrosive liquids and gases such as hydrogen sulfide, hydrochloric acid, bleach, bromides, waste water and hydrogen. Wrongful selection of a pressure sensor can lead to catastrophic failure and serious injury. When unsure, ask the pressure sensor manufacturer to provide a chemical compatibility chart with their products. In fluidic systems, such as water and hydraulics, one must understand how the water hammer and pressure transients effect the pressure sensor.
Halloween in New Orleans this year saw more than the usual array of costumed revelers on Bourbon Street. Indeed, hundreds of process automation professionals descended on the Crescent City to exchange ideas and best practices at Yokogawa's 2012 User Group Conference and Exhibition. The Control editorial team was on hand and developed this exclusive report of presentation highlights--on topics ranging from safety system risk management to the latest in data acquisition technology.
The editors of Control and Control Design compiled this special report from the 21st annual Automation Fair event, hosted by Rockwell Automation, in Philadelphia, November 5-8. This interactive PDF includes more than 20 articles documenting highlights ranging from executive keynotes and new product announcements to vertical industry forums and Rockwell Automation Process Solutions User Group and Safety Automation Forum meetings.
Wastewater treatment facilities are generally installed for one purpose - to clean up dirty water so that clean water can be discharged back into the environment. Nearly all municipal treatment plants rely on biological processes for wastewater treatment whereby bacteria and other microorganisms, frequently called 'bugs,' do this job of cleaning up the water.
What the 3S CoDeSys vulnerabilities are and what an attacker can do with them
How to find out what control/SCADA devices are affected
The risks and potential consequences to SCADA and control systems
The compensating controls that will help block known attack vectors
A number of security vulnerabilities in the CoDeSys Control Runtime System were disclosed in January 2012. In October 2012, fully functional attack tools were also released to the general public.
While CoDeSys is not widely known in the SCADA and ICS field, its product is embedded in many popular PLCs and industrial controllers. Many vendors are potentially vulnerable, and include devices used in all sectors of manufacturing and infrastructure. As a result, there is a risk that criminals or political groups may attempt to exploit them for either financial or ideological gain.
This White Paper summarizes the currently known facts about these vulnerabilities and associated attack tools. It also provides guidance regarding a number of mitigations and compensating controls that operators of SCADA and ICS systems can take to protect critical operations.
More than 60 percent of all industrial temperature measurement applications in the U.S. use thermocouples. Despite their widespread use, there are many misconceptions about thermocouples.
This paper will discuss some of the basic technical issues that engineers need to consider when applying thermocouples.