Explosion severe pump

Cavitation Formation of transient voids or vacuum bubbles in a liquid stream passing over a surface is called cavitation. This is often encountered arouna propellers, rudders, and struts and in pumps. When these bubbles collapse on a metal surface, there is a severe impact or explosive effec t that can cause considerable mechanical damage, and corrosion can be greatly accelerated because of the destruction of protective films. Redesign or a more resistant metal is generally required to avoid this problem. 

Following some mtxiifications to a pump, an operator pressed the stop button on the control panel and saw that the pump running light went out hence closed a remotely operated valve in the pump delivery line. Several houi s later the high-temperature alarm on the pump sounded soon afterward there was an explosion in the pump... 

Several hours later, the high-temperature alarm on the pump sounded. Because the operator had stopped the pump and seen the Pump Running light go out, he assumed the alami was faulty and ignored it. Soon afterward an explosion occurred in the pump. 

A more serious incident occurred at a plant in which ethylene oxide and aqueous ammonia were reacted to produce ethanolamine. Some ammonia got back into the ethylene oxide storage tank, past several check valves in series and a positive pump. It got past the pump through the relief valve, which discharged into the pump suction line. The ammonia reacted with 30 m of ethylene oxide in the storage tank. There w as a violent rupture of the tank, followed by an explosion of the vapor cloud, which caused damage and destruction over a wide area [4],... 

In 1966, a naphtha tanker, the Alva Cape, was involved in a collision near New York and was severely damaged. Some naphtha was spilled, and the rest was pumped out into another vessel. The owners wanted to move the ship to a shipyard where it could be gas-freed and the damage could be surveyed, but the New York Fire Department said that the ship s tanks should be inerted before it was moved. The salvage company, therefore, ordered some carbon dioxide cylinders and hoses. Two tanks were inerted without incident, but when carbon dioxide was discharged into a third tank, an explosion occurred, followed by a fire. Four men were killed, and further explosions occurred in other tanks when they were heated by the fire. 

Dinitrogen tetraoxide reacts explosively between —32° and — 90°C with propene, 1-butene, isobutene, 1,3-butadiene, cyclopentadiene and 1-hexene, but 6 other unsaturates failed to react [1]. Reaction of propene with the oxide at 2 bar/30°C to give lactic acid nitrate was proceeding in a pump-fed tubular reactor pilot plant. A violent explosion after several horns of steady operation was later ascribed to an overheated pump gland which recently had been tightened. A similar pump with a tight gland created a hot-spot at 200°C [2],... 

More than two years later a similar accident occurred in the same company, again the pump bearing overheated but on this occasion it was not the pump which exploded but a tanker refilling at a storage tank. The explosive decomposition had not been stopped by the cold transportation hose, as in 1999, which allowed it to enter the vehicle s tank and explode. The explosion caused injury to 11 people and severe damage to the immediate surroundings. 

Normally where it is necessary, fireproofing is preferred over water spray for several reasons. The fireproofing is a passive inherent safety feature, while the water spray is a vulnerable active system that requires auxiliary control to be activated. Additionally the water spray relies on supplemental support systems that may be vulnerable to failures, i.e., pumps, distribution network, etc. The integrity of fireproofing systems is generally considered superior to explosion incidents compared to water spray piping systems. The typical application of water sprays in place of fireproofing is for vessel protection. 

The local fire department arrivedjust after the explosion at 11 22 A.M. With the limited water supply on two of the fire trucks and the utilization of another fire truck to pump water directly from a nearby cooling water tower basin, the firemen were able to slow the fire spread. By 11 30 A.M., the Maintenance Department was able to transfer the set of batteries from the impaired diesel fire pump to the other diesel fire pump. On completion of this task, this diesel fire pump was started. The automatic deluge sprinkler protection was severely damaged by the fire/explosions and had to be valved into the off position. Three fixed monitors were turned onto lull flow and directed at the fire. Also, the firemen and fire brigade used two hose streams olF nearby fire hydrants for fire fighting purposes. At 11 58 A.M., the fire was under control. Final fire extinguishment was accomplished by 12 10 p.m. 

A small sample of AN in an evacuated tube was heated gradually to desired temps, and samples of the gas produced by decompn were pumped out, measured and tested. Decompn proceeded very quietly at temps below 200°, and only a small amt of gas was formed even on heating for several hours. The reaction proceeded more vigorously at higher temps and became rather violent at ca 260°. Between 260 and 269° gray smoke was produced and, after a time, an explosion took olacr. This also Orftirred after hearing... 

Detonating Red Substance (Fr Corps rouge deto-nanc). It is a reddish-brown, very sensitive explosive substance first found during WWI in the plants manufg TNT, on the walls of various lead vessels, such as nitrators, tanks, pumps, pipes, etc. Similar material was found on the walls of some iron vessels. The fires and explosions in several French TNT plants were presumed to be initiated by that "red substance ... 

It is commonly accepted in the explosive and mining industry that at least 40-50 percent emulsion is required to protect the Heavy ANFO blend from borehole water intrusion. Pumped explosive blends with 60-80 percent emulsion can even be used when severe water conditions are encountered. These products can be pumped through a loading hose, which can be lowered to the bottom of the borehole and displace the water during loading. Trucks similar to that shown in Fig. 37.9 can be used for these products. Most Heavy ANFO products are more simply mixed and loaded through an auger into the top of boreholes. For Heavy ANFO products... 

The diazonium salt that should be used in this experiment is benzenediazonium fluoborate (C6H5N2BF4, M = 191.9). The great majority of diazonium salts are notoriously unstable solids and ean deeompose with explosive violence. The fluoborates are by far the safest to use and are not known to explode however, reasonable caution should be used in preparing the compound. Since even benzenediazonium fluoborate will decompose slowly, it should not be prepared too far in advance, and it must be stored in a refrigerator. A simple high-yield procedure for its preparation has been given by Dunker, Starkey, and Jenkins. Recrystallization of the product from 5 percent fluoboric acid yields white needlelike crystals, which can be dried by vacuum pumping at 1 Torr for several hours, t... 

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