Showing posts with label safety. Show all posts
Showing posts with label safety. Show all posts

Developing an Effective Alarm Strategy

Petrochemical plant refinery tanker ship
Effective alarm plans are an important part of a process
Industrial process control operators and designers have the capability to measure many aspects of machine operation and process performance. Determining the elements to measure, method of measurement, and how to handle and process the derived information can be challenging, but can also impact the security, performance, and safety of an operation. A plan for monitoring, reporting, and responding to abnormal process conditions, if properly developed and executed, can yield real benefits to a process operator. A protocol that is not well conceived may produce a negative operational impact by creating events that unnecessarily draw resources away from productive endeavor. That protocol, or plan, is often referred to as an alarm plan.

There are numerous forces that can influence the development and implementation of an alarm plan. Each operation must incorporate its own set of external regulatory requirements, internal procedures and policies into a complete alarm protocol. Distilling that macro description down to a workable set of procedures and response tasks is where the real work begins. There is, however, a basic framework that can help organize your thinking and focus on what is most important.

  • What parameters define the process or operation?
    Produce a schedule of every non-human element that is required to make the process function. This will require drilling down through every machine and material that is part of the operation. Expect the schedule to be extensive, even huge. If it is not, consider that your analysis may not be reaching deep enough. The goal here is to create an overview of what makes the process work and provide a tool for systematically studying the process elements and gleaning possible commonalities or relationships among them. Consider disregarding things that cannot be measured, since that prevents the derivation of data for evaluation. Review the completed schedule and decide which parameters shall be measured and evaluated for proper performance.
  • What level of measurement is needed for each monitored parameter?
    An assessment of the needed accuracy, frequency, and resolution for parameter measurement will help define the requirements for instrumentation or other devices used to monitor a particular item. The goal is to make sure the monitoring device is capable of detecting and delivering information of sufficient quality to make decisions.
  • Define the limits of acceptability for each monitored parameter.
    Until the endpoint of the process or operation, each step is likely dependent in some way on previous steps. The output of each step becomes the input of the next. While this, in many cases, may be an oversimplification, it is important to consider the relationships between the
    industrial control automated filling line process automation
    High speed filling operation
     tasks and operations that comprise the process. Monitored parameters should relate to the successful completion of a process step, though not necessarily be a direct indicator of success. The maintenance of the parameter within certain bounds may be used as an indicator that a component of successful completion was properly attained. Defining limits of acceptability may involve an element of subjectivity and will likely be customized to accommodate the process. Each organization shall evaluate their operation and determine limits based upon intimate process knowledge and experience.
  • Define abnormal operation for each monitored parameter.
    Abnormal operation may not necessarily be any value not within what is considered acceptable. Consider abnormal to be the range of values that would be cause for notification of the operator, or even automated or human intervention. Note that the definition of unacceptable or abnormal operation might appropriately include filters or defined relationships with other parameters. An example of a simple filter is a time delay. If the measured variable exceeds the specified limit for 2 seconds, it make not be significant. If the threshold is exceeded for 2 minutes, it may be cause to take action. As with the limits of acceptability, developing the definition of abnormal operation for each parameter will be customized for each process.
  • Provide a defined response for every alarm occurrence.
    If it is important to monitor something, then it is likely important to do something when things get out of hand. Human executed alarm response should be concise and uncomplicated, to reduce the probability of error. Automated response should be designed in a manner that provides for functional testing on a regular basis. The scope of the response will be specific for each process, with the level of response depending upon factors determined by the process operators. Response can be as simple as annunciating the condition at a monitoring station, or as dire as shutting down part or all of the process operation.
  • Review every alarm occurrence
    Each alarm event should be logged and reviewed. Consider whether the event detection and response was adequate and beneficial. If the results were less than expected or desired, assess whether changes can be made to provide improved results in the future. The alarm plan is unlikely to be perfect in its first incarnation. Be prepared to reevaluate and make changes to improve performance.
The exercise of developing a comprehensive alarm plan will help to build understanding of process operation for all involved parties. This article is but a brief synopsis of the subject, intended to get the reader on the path of developing a useful alarm plan. Your alarm plan should an extension of process operation decision making, and have a goal of enhancing safety and reducing loss. Contact the process control and combustion specialists at CTI-Controltech for additional input.

Learn From Industrial Accident Review and Analysis - Video Included

petroleum storage tanks
Every industrial facility has a signature array of hazards
Industrial accidents range in severity and impact from minuscule to catastrophic. As operators, owners, or technicians involved with industrial operations, we all have a degree of moral, ethical, and legal responsibility to conduct our work in a manner that does not unduly endanger personnel, property, or the environment. Maintaining a diligent safety stance can be helped by reviewing industrial accidents at other facilities. There is much to learn from these unfortunate events, even when they happen in an industry that may seem somewhat removed from your own.

The U.S. Chemical Safety Board, or CSB, is an independent federal agency that investigates industrial chemical accidents. Below, find one of their video reenactments of an explosion that occurred in Texas in 2013, along with their findings regarding the cause of the incident. Check out the video and sharpen your senses to evaluate potential trouble spots in your own operation.

Contact CTI Controltech for any safety related information you may need concerning their lines of industrial process control and combustion products.

Industrial Burners and Safety Systems - Part Three

CTi Combustion

Igniters

Igniters provide proven ignition energy to immediately light-off the burner. They are permanently installed. Igniters are classified as follows by NFPA:

  • Class 3 special: High energy igniter (HEI) capable of directly igniting the main burner fuel. Generally consists of a spark-rod, and power pack to deliver the high voltage pulse train, and required cabling. Operation time of igniter is no longer than required to light-off burner, within maximum allowed trial-for-ignition time.
  • Class 3: Low capacity igniter applied particularly to gas and oil burners. Ignites the fuel input to the burner under prescribed light-off conditions. The range of class 3 igniters generally do not exceed 4 percent of full load burner input. Operation time of igniter is not longer than required to light-off the burner, within the maximum allowed trial-for-ignition time.
  • Class 2: Medium capability igniter applied particularly to gas and oil burners to ignite the fuel input to the burner under prescribed light-off conditions. The range of class 2 igniters generally is 4 to 10 percent of full-load burner input. Class 2 igniters may remain in operation to support ignition under low-load or adverse operating conditions. Class 2 igniters cannot be used to extend main burner turn-down range.
  • Class 1: High capacity igniter used to ignite the fuel input through the burner. Supports ignition under any burner light-off or operating conditions. Its location and capacity provide sufficient ignition energy at its associated burner to raise any credible combination of burner inputs of both fuel and air above the minimum ignition temperature. Tests are to be performed with this ignition system in service to verify that the igniter furnished meets the requirement of this class as specified in its design. Class 1 igniters can be used to extend the main burner’s turndown, where they are in service and flame if proved.

Industrial Burners and Safety Systems - Part One

Fireye Burner Safety
Fireye Burner Safety Systems
Burners are simple devices that convert fossil fuels into heat energy. In order to achieve safe and reliable operation, each burner must be equipped with a monitoring and control system. The complexity of a safe and reliable system is relative to the complexity of the process at hand. This system can be as simple as a single burner using a single fuel, to a complex multi-burner environment where many burners fire into a common combustion chamber where multiple fuels are burned simultaneously. Conditions affecting the complexity of control systems is not necessarily dependent upon large burner input, but IS dependent upon the following conditions:
  • Type of process. 
  • Type of burner. 
  • Multi- or single burner environment. 
  • Multi or single fuel operation. 
  • Safety hazard of fuel burner. 
  • Local codes and standards. 
  • Redundancy and reliability factors. 
  • Continuous or intermittent burner operation. 
Recent technological advances require knowledge of applications and systems and should be applied only by qualified technicians. Standards are set by local authorities and must be understood and properly operated in order to assure that safety requirements are met.

Flame Discrimination and Detection for Multi-fuel Applications

Safe, reliable infrared and ultraviolet flame discrimination and detection for multi-fuel applications.

Flame scanners are used to detect emissions from fossil fuel flames. These can be gaseous fuel, light petroleum distillates, diesel fuels, heavy fuel oils and a variety of coals. They are suited for application to multiple burner furnaces in utilities and pulp and paper plants, industrial application such as petrochemical, refinery and chemical production, through to industrial boilers. Flame temperature measurement can be used to monitor and report on many applications including specialized burners used in applications such as Low NOx, Incineration and sulfur recovery.