Boiler explosion

Metallurgical detective work after a boiler explosion... 

The original steam generators were simple pressure vessels that were prone to caiasirophic failures and loss of life. Due to better boiler design, tube-fired boilers, and boiler inspections, the incidence of catastrophic failure is now to a rare event (about once every 100,000 vessel-years). In Great Britain in 1866, there were 74 steam boiler explosions causing 77 deaths. This was reduced to 17 explo.sions and 8 deaths in 1900 as a result of inspections performed by the Manchester Steam User Association. In the United States, the American Society of Mechanical Engineers established the ASME Pressure Ves.sel Codes with comparable reductions. 

Another simple hazard is a pressure vessel rupture due lo over pressure. A steam vessel rupture may scald vorkers and injure them viih shrapnel. Many people died in the last century from boiler explosions. The ves-... 

Testing, of course, must be thorough. The following incident is described in the form of a conversation between an inspector investigating a boiler explosion and the maintenance foreman [12]. 

This incident occurred in the 19th century when boiler explosions were much more frequent than they are today. But are you sure something similar could not occur today Read Sections 10.7.2 (b) and (c) before you decide. 

Insights into the human causes of accidents for a specific category of process plant installations are provided by the Oil Insurance Association report on boiler safety (Oil Insurance Association, 1971). This report provides a large number of case studies of human errors that have given rise to boiler explosions. 

Inspection by independent persons or bodies for safety purposes goes back to the middle of the nineteenth century. At that time, the focus of concern was the explosion of steam boilers, and this hazard was most prevalent in the textile industry. Consequently, a group of public-spirited individuals formed the Manchester Steam Users Association for the Prevention of Boiler Explosion. This body carried out boiler examinations and later added insurance as an inducement to the plant owners. By the beginning of the twentieth century steam and gas engines and electrical machines had been added, followed by lifts, cranes and hoisting machines. 

While boiler explosions fortunately do not occur too often today because of the existence of extensive safety devices as well as the regular program of inspection, their effects can be catastrophic. Similarly, sudden and unforeseen damage caused by the overheating of multi-tubular steam boilers due to lack of water can lead to eventual furnace collapse, with very extensive repair costs as well as lost production. 

Inspecting and maintaining the interlock system is a vital function. It is required to ensure general safety and to avoid risks of boiler explosion. Interlocks provide for the safe sequence of boiler startup and shutdown procedures. 

In addition to the many different forms of boiler section ferrous corrosion already described, several other less common types occasionally develop. In particular, corrosion processes may evolve that are interrelated with stress, deposition, and/or high temperatures (thermal effect corrosion), and together these may lead to metal fatigue (metal fatigue corrosion), metal failure, and even more serious problems such as the risk of a boiler explosion. 

A boiler explosion of limited intensity. It may still cause flames to be thrown several feet beyond the boiler. 

A physical explosion, for example, a boiler explosion, a pressure vessel failure, or a BLEVE (Boiling Liquid Expanding Vapor Explosion), is not necessarily caused by a chemical reaction. Chemical explosions are characterized as detonations, deflagrations, and thermal explosions. In the case of a detonation or deflagration (e.g., explosive burning), a reaction front is present that proceeds through the material. A detonation proceeds by a shock wave with a velocity exceeding the speed of sound in the unreacted material. A... 

However, steam cars needed up to half an hour to build up a head of steam and required large amounts of water and wood. Then, there was also the fear of boiler explosions. 

E. Statistical Survey of Smelt-Water Boiler Explosions. 148... 

Molten salt (smelt) tapped from black liquor boilers is quenched and dissolved to form green liquor in tanks near the boiler. On occasion, explosions have resulted which severely damaged the dissolver tank. (These events are different from the smelt-water boiler explosions described later.)... 

The research results clearly indicated that the smelt-water explosion yielded a localized, high-energy shock wave which moved at velocities of over 700 m/sec. The maximum pressure rise was achieved in about 1 msec. These facts were related to the results found in real boiler explosions in descriptive terms as there were 3-4 inch depressions 3 to 6 feet... 

Black Liquor Recovery Boiler Explosion List"... 

Bergman, S. G. A., and Laufke, H. (1981). Recovery Boiler Explosions, SPCl-Rep. No. 35. The Swedish Steam Users Association, Stockholm, Sweden. 

Because of the number of boiler explosions and related fatalities in Europe, a select committee of the British House of Commons, looking into the explosions on steam ships reported in firne 1817 ... 

Many explosions were caused by inadequate boiler design or by people rendering the Safety Valves inoperative in order to increase the boiler pressure. Due to further explosions, 1882 saw the passing of the Boiler Explosion Act, in which a boiler was defined as... 

In Great Britain, voluntary bodies such as the Steam Users Association supplied reports to the government beginning in 1854. In the period from 1881 to 1907, there were still a total of 1871 boiler explosions investigated by the Board of Trade. These explosions accounted for 732 fatalities and 1563 non-fatal injuries. 

In the United States, the safety records were just as bad. In the period from 1906 to 1911, there were 1700 boiler explosions in the New England area alone, accounting for 1300 fatalities. 

The American Society of Mechanical Engineers (ASME), was asked by the government to formulate a design code, and developed the famous Boiler and Pressure Vessel Code between 1911 and 1914 as a set of safety mles to address the serious problem of boiler explosions in the United States. Average steam pressure in those days had reached only about 300 PSI (20 bar). Europe and other parts of the world used the code as a basis for their own safety mles. 

Steam boilers are commonly used in power plants and industries of all kinds. They generally are taken for granted now, but in the second half of the nineteenth century boilers blew up with alarming regularity. Records indicate that from 1870 to 1910 there were at least 10,000 boiler explosions in the United States and adjacent areas of Canada and Mexico that is, more than one recorded explosion every 36 hours By 1910, the rate had jumped to between 1,300 and 1,400 per year. On October 8, 1894, in the Henry Clay Mine in Shamokin, Pennsylvania, 27 boilers disintegrated almost simultaneously Mainly because of the incorporation of the ASME Boiler Code into laws, boiler explosions have decreased dramatically.41... 

The USS Essex and three other LHD-class amphibious assault ships utilize furnace cameras to observe flame patterns and identify potential problems in a boiler combustion monitoring system and also monitor a pushbutton igniter-control system. Previously, a sailor monitored the fires through a small porthole, and an engineer in a flame-resistant jacket lit the boilers with a torch. If unburned fuel was in the boiler, explosions could occur. 

Flame safeguarding is a very important part of combustion control. Statistics show that the bulk of boiler explosions occur during start-up, either cold or hot. On-off operation such as setting safety... 

The second type of explosion occurs via physical or chemical means, as in the case of a hot-water heater or boiler explosion. The water inside the heater turns to steam when overheated, which results in a pressure inaease inside the container, and the container fails at its weakest point. This is by far the most common type of accidental explosion. 

Aniline—Boilers—Explosives—Iron— Sugar—W atches— Woollens, Etc. 

By the beginning of the twentieth century, the number of industrial accidents had risen to unacceptably high levels. For example, between the years 1870 and 1910, at least 10,(XX) boiler explosions occurred in North America. By the year 1910, the rate of such explosions had reached approximately 1,400 per year. 

When the pressure of a fluid inside a vessel exceeds the vessel s strength, it will fail by rupture. A slow rupture may occur by popping rivets or by opening a crack. If the rupture is rapid, the vessel can literally explode, generating metal fragments and a shock wave with blast effects as damaging as those of exploding bombs. Boiler explosions are often disastrous. 

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