22 Hurt After Boiler Erupts

[Flashermac]

 

A five-meter-high boiler exploded at a dyeing plant in Samut Prakan’s Muang district early yesterday, injuring some 22 workers and residents. Several nearby homes were also damaged.

 

Most of the victims - 17 - were migrants, including a Myanmar man in charge of running the boiler. Four others were from a Thai family living next door to the factory.

 

The entire plant and its machinery, owned by Wongwisit Dyeing Co, was destroyed. Damage was estimated at about Bt10 million.

 

The site has been declared off-limits pending an inspection by police to determine the cause of the accident. No one has been charged yet.

 

The explosion blew out the upper and lower lids of the three-metre-wide boiler and sent the main unit flying some distance away from its original site. The explosion levelled six homes and damaged a few others while setting fire to machinery on the other side of the building. The blaze was extinguished in 30 minutes.

 

Police said six workers were on duty, including the operator, identified as Sor Mon San, 25, who was taken to the intensive care unit of a hospital with burns all over his body from scalding water.

 

A police source said there may have been problems with water pipes cooling the boiler, causing steam pressure to build up and exceed the safe limit and explode.

 

Thawee Kaewchart said the blast before 5.30am sent him and two children diving into a ditch by their house, which was flattened by the force of the blast. Thawee had burns on his arm and both of his children had burns on a large part of their bodies.

 

Jeerasak Sukhonthachart, permanent secretary of the Labour Ministry, said registered migrant workers would be provided assistance from the Social Security scheme while those unregistered would get initial assistance from their employer.

 

He said he would inspect the factory then visit those receiving treatment at Samut Prakan Hospital.

 

 

http://www.nationmultimedia.com/national/22-hurt-after-boiler-erupts-30241122.html

[cavanami]

> ...may have been problems with water pipes cooling the boiler...

 

A boiler is used to heat water to make steam. I have never seen a boiler with water pipes to cool the boiler.

 

If the boiler has too much pressure, the heat source is throttled back. If the boiler gets too hot, make up might

be added and once again, the heat source is throttled back.

 

This was most likely a high pressure boiler to cause that much damage. Boiler inspections? was the operator

trained/certified to operate such a boiler?

[Mekong]

> ...may have been problems with water pipes cooling the boiler...

 

A boiler is used to heat water to make steam. I have never seen a boiler with water pipes to cool the boiler.

 

If the boiler has too much pressure, the heat source is throttled back. If the boiler gets too hot, make up might

be added and once again, the heat source is throttled back.

 

This was most likely a high pressure boiler to cause that much damage. Boiler inspections? was the operator

trained/certified to operate such a boiler?

 

Think about it Cav.

 

Boiler Feed Water removes the heat from the furnace and in the process is turned into steam. Think of it like a kettle, if the element is not covered it trips out due to thermal overload, yet with water in it it keeps the element below overload point even though it is producing steam out of the spout, Second Law of Themodynamics also known as the Rankine Cycle. Three Mile Island was classed as a LOCA (Loss of Coolant Accident) but the coolant in question was the Primary Circuit Steam Cycle, go figure. I know it goes against rational thought but the water/steam cycle is the cooling of the furnace

 

IMHO looking at the Photograph this was not a H.P. Boiler, it looks similar to a Cochran Wee Chieftain which run at about 10.3 Barg (150 psi) producing about 3,000 Kg/h (1,800 kWh) of saturated steam. To put things in perspective the pair that I am currently working on run at 172.37 Barg (2,500 psi) producing 1,000,000 Kg/h (600,000 kWh) of superheated steam. That is what I call High Pressure and in decent Volumes.

 

As for Boiler inspections I am with you on this one, any Boiler or Pressure Vessel has to comply with ASME BPVC (Boiler and Pressure Vessel Code) also known as ASME Section VIII Division I which covers everything from Materials of Construction through Fabrication Phase and the Design and MAINTENANCE of over pressure systems. And there lies the problem, maintenance or should I say lack off.

 

There are also other International Standards in place, I won't call them guidelines but RULES such as NFPA 85, Boiler and Combustion Systems Hazard Codes, IEC 61508 Functional Safety of Electrical / Electronic / Programmable Related Electronic Safety Related Systems, IEC 61511 Functional Safety - Safety Instrumented Systems for the Process Industry Sector.

 

The Operator does not need to be well trained, a well Engineered and Maintained SIS (Safety Instrumented System) takes the operator out of the equation. Unfortunately Safety and Maintenance costs money which unscrupulous facility owners see as eating into their profit margin. As a CFSE (Certified Functional Safety Engineer) this this really ticks me off, one can spend 18 months to 2 years designing and engineering a system only for it to be totally ignored after 6 months of profits. There is no such thing as "An Industrial Accident" just a previously identified sequence of events that has been ignored.

 

OK Rant over!

[cavanami]

If I remember correctly, boilers have or should have a fire prevention system. We did a boiler system last year,

a Kessel boiler, and the specs were well in place.

Overtemp. over pressure, etc all with measures to control the mishap and prevent such an "accident" as what happened

in Samut Prakan.

 

TIT

[Specialist]

Mekong, the water was more than just the coolant at Three Mile Island. It was also the neutron moderator. Without the moderator, the nuclear chain reaction stops, all by itself.

 

That design is inherently safe, unlike the graphite-moderated RBMK reactors at Chernobyl.