Process safety and Maintenance spends

Penny wise pound foolish. If you do not maintain your assets well, you will end up paying more in the long run. Maintaining your assets not only improves process safety, it improves reliability and morale of the plant and maintenance personnel.In these days of cost cutting and lack of competency in companies, many plant managers turn a blind eye to the deteriorating assets. This also brings me to another question - how much can you flog your equipment? By debottlenecking efforts, you may increase your capacity by 30% but have you studied the effect of running on high load on the remaining plant equipment?
Read an article by  Jim McCarty on "spend now, save later" in this link. It applies to chemical plants also.

Process safety and technology

I have always strongly felt that technology alone cannot solve your process safety problems, its your approach towards your people and your plant that will keep you safe.
An article in the Moscow Times mentions "The United States suffered only 20 aviation fatalities in 2010, according to the Aviation Safety Database. Russia suffered 110 fatalities in the same year, the bulk of which were accounted for by the Polish Tupolev-154 that crashed in foggy conditions near Smolensk in April.
While declining to comment on the situation in Russia, one U.S. aviation professional concurred that "technology does not equal safety."
"The U.S. is lagging in air traffic control — we're using 1950s equipment and ground-based radar that means we have to fly these circuitous, occasionally inefficient routes — but it is safe," said Charles Duncan, United Airlines vice president for transatlantic, Middle East and India sales, in an interview with The Moscow Times.

 "If fewer airlines meant safer skies, the world would be a much simpler place than it is," Oleg Smirnov, chairman of the Federal Transport Agency's commission on civil aviation, said in reference to government plans to slash some of Russia's hundred-plus airlines.The real problem is a misguided, laissez-faire policy of registration and approval that allows "almost anyone" to set up an airline extremely easily, Smirnov said. He also blamed a culture that promotes profits over professionalism and a blurred hierarchy of responsibility that allows companies to pressure pilots not to abort flights."

Doesn't the above sound familiar in our Chemical Industry, too? Putting profits over people and plant will not help you even if you have the latest technology. Read the full news article in this link. 

Refinery cited for PSM violations

A news item mentions that a refinery has been cited in the US for PSM violations. Included in the serious violations are "failing to investigate incidents as being related to process safety management, equipment repair, address inconsistent thickness measurements collected during pressure vessel inspections, maintain accurate and updated engineering drawings, and ensure that written operating procedures were certified as being current and accurate".
Read the article in this link

Dust explosions - Ignorance is Deadly!

A dust explosion can be deadly. The sugar dust explosion at Imperial Sugar Industries, Port Wentworth, Georgia, USA in 2008 killed 11 people and injured 42 workers, some of them critically. Dust explosions have known to occur as far back as the 18^th century when a baker reported an explosion in a flour warehouse. Most organic materials and many metals will burn or explode if they are finely divided and dispersed in air and contact an ignition source. Dust explosions have occurred in a many industries including flour, coal, aluminum, plastic, vitamins, pharmaceutical compounds, sugar, tea, corn starch etc.A normal fire triangle consists of fuel, oxygen and ignition source. However for a dust explosion to occur, two additional elements are required – dispersion of the combustible dust in air in a concentration sufficient to ignite and confinement.Hence for a dust explosion to occur, the following are needed:

1. Fuel

2. Air (oxygen)

3. Ignition source

4. Dispersion of combustible dust

5. Confinement (The confinement causes and explosion to occur)

The above 5 elements needed for a dust explosion to occur are called a dust explosion pentagon.

The damage from a dust explosion is catastrophic because the primary dust explosion causes the loose dust present in beams and on top of other equipment to shake loose and fall down. This causes a secondary explosion which is far more deadly than the first one. Thus the domino effect of the primary dust explosion can be carried forward through elevators, conveyors and silos. The result is a catastrophic explosion. NFPA 654 states that dust layers 1/32 inch thick can create hazardous conditions.

The Material Safety Data Sheets for many substances do not indicate the potential for dust explosions. Many organisations implement changes that inadvertently create an atmosphere for a dust explosion. Enclosing an open conveyor is one such change. The Chemical Safety Board of the USA has recorded 197 incidents involving dust explosions since 1980, with 109 fatalities and 592 injuries.

Preventing dust explosions:

To prevent a dust explosion, it is necessary to eliminate the fuel (combustible dust), oxygen or ignition source.

While complete elimination of the fuel (combustible dust) may not be possible, it is possible to eliminate the chance of a secondary explosion by proper training and housekeeping. Dust collectors must be maintained properly to avoid a drop in their collection efficiency. Another method is to add an inert material like rock dust into the combustible dust.

Complete removal of oxygen is also not possible in a system comprising of conveyors, elevators, bins and silos. Inerting (use of an inert gas) also brings along safety issues of asphyxiation of personnel.

Eliminating all sources of ignition may also not be possible. Normal sources of ignition include the following:

•   Hot bearings and surfaces
•   Static electricity
•   Hot work (welding, cutting, brazing or spark producing activity)
•   Electrical system including faulty equipment

Mitigating dust explosions:

Effective mitigation requires properly designed engineering solutions. These solutions include explosion venting, explosion suppression and explosion isolation.

Explosion Venting

Explosion vents are designed to direct the gases from a dust explosion to a safe location and prevent over pressurization and damaging the equipment. The location of the vent should be placed in such a way as not to harm personnel.

Explosion Suppression

An explosion suppression system consists of a pressure or temperature sensor that detects the start of a dust explosion and a chemical suppression or inerting system that is automatically activated when the start of an explosion is detected. The chemical suppression or inerting system cools or extinguishes the flame front before it can cause damage.

Explosion Isolation

The explosion isolation systems work on the principle of detecting a dust explosion early and isolating long sections of pipelines leading to the protected equipment. A fast acting valve is used to isolate the protected equipment. The explosion venting systems are not suitable for dusts that burn quickly as the flame front speed will be high in such cases.

Pictures of the boiler gas explosion

Thanks to Divyang B Shah for sending pictures of the boiler gas explosion I had mentioned two posts back. Pictures always speak a thousand words!

 

Generation next and Process Safety

I had given a presentation on Process safety management  to the Ankleshwar Chapter of Indian Institute of Chemical Engineers recently. A large number of young engineers were present. The chapter is doing good work by exposing the young engineers to the concepts of process safety management. In the audience, there were also young mechanical engineers who were working in chemical plants. We can prevent another Bhopal only by passing on the lessons learnt from Bhopal to the younger generation. The memories of Bhopal should not die with this generation but must always be kept fresh. Read my earlier post on the "Lessons from Bhopal - more so relevant today"

Boiler explosion in Gujarat

"The Hindu" newspaper has reported a boiler explosion in a diary in Gujarat that has killed 7 and injured 21 others. Apparently a leaking gas pipeline was being repaired when the explosion occurred. In many companies, I have observed hot work allowed in many gas fired utility boilers and incinerators after the operators have just isolated the natural gas supply but not blinding it. In one case, the operators had isolated the natural gas to the burner of a utility boiler and removed the burner. Their argument was that they have disconnected the burner and hence no gas could get into the boiler. However, the open gas pipe (after the burner was removed) was pointing towards the boiler and when we tested the area around the pipe with a flammable gas detector, it was in flammable range. Do not depend on isolation valves alone to stop the gas from leaking through.
Read about the boiler explosion in this link.

Caustic Soda - process safety

As part of their Responsible Care commitment, DOW Chemicals has published a pdf file called "Caustic Soda Solution Handbook". It contains useful data that will be required on a day to day basis for storage and handling as well as transportation. Download it from this link. (large file...be patient)

Bromine leak in Russia

The BBC reports that at least 42 people received hospital treatment in the Russian city of Chelyabinsk after a leak of the toxic chemical bromine in a rail incident. Apparently about 2000 two liter glass bottles of bromine was being transported by rail and it is estimated that about 24 to 50 liters were released. Read the report in this link See a video of the leak in this link.

"Automation Addiction" in flying and its relation to process safety

Joan Lowy of AP has written an article mentioning the following:
'Pilots' "automation addiction" has eroded their flying skills to the point that they sometimes don't know how to recover from stalls and other mid-flight problems, say pilots and safety officials. The weakened skills have contributed to hundreds of deaths in airline crashes in the last five years.
Some 51 loss of control" accidents occurred in which planes stalled in flight or got into unusual positions from which pilots were unable to recover, making it the most common type of airline accident, according to the International Air Transport Association.
"We're seeing a new breed of accident with these state-of-the art planes," said Rory Kay, an airline captain and co-chair of a Federal Aviation Administration advisory committee on pilot training. "We're forgetting how to fly."
Read the article in this link.

This has direct relations to the Chemical Process Industry. With so much automation in our idndustry, I am sure that operators are really forgetting their troubleshooting skills in the event of an emergency. Dr Trevor Kletz has always propounded that things must be kept simple and the way process control manufacturers are developing and implementing "solutions" for process safety, it leaves me dumbstruck. In another post, I had written that today I see operators who are becoming "procedural robots" during emergencies and plant upsets. This is a dangerous situation. Simulators do help in keeping operators skills up to date but management often thinks that it is a waste of money. Cluster simulation training ( for processes that have the same licensor) could be started, with companies pooling in for a common simulator training facility.

Counterfeit bearings and process safety

An interesting article about counterfeit bearings mentions how good the counterfeiters are getting. In today's competitive environment, organisations look at cutting costs. Sometimes this may lead one to purchase a lower priced product that seems to meet all specs, but can be a counterfeit. I know of cases where wrong metal plate materials have caused incidents. Make sure you have a robust positive material identification system for your incoming items.
Read the article here. Are you bearing an unnecessary risk? Randy L. Bowen, SKF USACounterfeit bearings can lead to equipment downtime and safety problems.

Earthquakes and Process Safety

The recent earthquake that hit the East coast of US has triggered a number of articles on the possibility of earthquakes in areas which are not normally earthquake prone. An article in the Economic Times mentions the following:
'Residents of the east coast of the United States generally think of themselves as safe from earthquakes. This feeling was given a jolt on August 23 when a 5.9-magnitude earthquake hit near the town Mineral in Virginia. Nobody died, but a nuclear reactor there shut down by itself as its electricity supply tripped. This nuclear plant was designed to withstand earthquakes of magnitude up to 6.2 on the Richter scale. The designers of the plant had thought that Virginia would not experience stronger earthquakes, but the tremor last week was uncomfortably close to the limit.
Central India, on the other hand, has a high degree of bulge from flexure due to stress built up from the Himalayas. Recent studies have discovered this stress as much as 1,000 km south of the Himalayas. The 1993 Latur earthquake had happened at a region of stress. This earthquake, measuring 6.4, had shocked seismologists as they had never expected an earthquake to happen there. The lessons of the recent spate of intraplate earthquakes are clear. A large portion of India lies in hazardous zones, a fact that is relevant to rapidly expanding nuclear power industry in India.
Given the ability of intraplate earthquakes to surprise, one should expect damaging earthquakes at many places in the country. Even southern cities are not entirely safe, although seismologists do not expect even moderate earthquakes to happen there. Many high-rise buildings are built without following any codes. Especially vulnerable are those on stilts and those built on or near dried lakes. The city of Bangalore is full of such buildings. So are several other cities in the country. Are we inching towards one of our worst natural disasters? "
Read the full article in this link.
A chemical plant that is not designed to the current earthquake resistance standards can be the cause of catastrophic accidents. There are large storage tanks containing highly hazardous materials in many plants and imagine the impact if their contents come out during an unanticipated earthquake!