Fire cracker

More peaceful uses of these crude articles appeared in the form of fire crackers - the first fireworks One mixture corresponded quite closely to modern gunpowder in that it contained saltpetre, sulfur and willow charcoal. The fire cracker was said to consist of a loosely-filled parchment tube tied tightly at both ends and with the introduction of a small hole to accept a match or fuse. All of these incendiary mixtures, presumably containing saltpetre, are mentioned in Chinese work dating... 

Olefin plants all have two main parts the pyrolysis or cracking section and the purification or distillation section. The ethane cracker in Figure 5—2 has a pyrolysis (from the Greek, pyros, fire) section that consists of a gas-fired furnace where the cracking takes place. The newer individual furnaces can each handle more than 400 million pounds per year of ethane feed. 

Complex process units such as catalytic crackers, hydrocrackers, ethylene units, hydrotreaters, or large crude distilling units typically containing high fire potential equipment. 

Figure 9.38, for example, shows the application of the chemical mass balance approach to the fine particle fraction of particles collected at a location in Philadelphia (Dzubay et at., 1988 Olmez et al., 1988 Gordon, 1988). If the set of equations (II) fitted the data perfectly, the sum of the contributions of the various sources would be 100% for each element. Clearly, from the top frame, this is not the case for a number of elements, and both positive and negative deviations from 100% can be seen. However, the contributions of several sources are clear Si and Fe from soil, Ni, V, and Ca from oil-fired power plants, Ti from a paint pigment plant, La, Ce, and Sm from a catalytic cracker, K, Zn, and Sn from an incinerator, Sb from an antimony roaster, and Pb and Br from motor vehicles. 

In the celebrated book of Marcus Graecus, Liber ignium ad comburendos kostes,10 Greek fire and other incendiaries are described fully, as is also black powder and its use in rockets and crackers. This work was quoted by the Arabian physician, Mesue, in the ninth century, and was probably written during the eighth. 

The time between the ignition of the fireworks and the existence of a violent fire has not yet been concluded. Some said that the fire expanded in several seconds, whereas others maintained that it it took one minute. Some people confined in the shop said that the sound of the fireworks was considerable, not like that of crackers but rather like that of skyrockets. 

Economics The MTO process competes favorably with conventional liquid crackers due to lower capital investment. It is also an ideal vehicle to debottleneck existing ethylene plants and, unlike conventional steam crackers, the MTO process is a continuous reactor system with no fired heaters. 

In general, flames, hot air, fire dust sparks, sparks or shock waves help the propagation of fire or explosion. Four of the former only promote the burning of the compositions by direct contact, but the latter causes a detonation, even when the composition is fairly distant from the source. However in toy fireworks the item which produces a shock wave is limited to crackers. It is necessary therefore to draw a clear line between crackers and other items when handling toy fireworks. 

The first fire-arms weie doubtless rockets, in which the force of tb explosion carried the tube. To these probably succeeded something of the nature of the fire-works known as Roman candles, in which pellets are loaded into a tube and fired by a match at the tube-mouth. The tubes were of bamboo, paper, or cloth, probably each of these, according to circumstances. (For early notices, see Ounpow-DBR.) The cracker was used as a grenade anciently in China, and in the 8th century by the Greeks. 

Methanol is endothermally cracked over a catalyst to produce synthesis gas plus traces of methanol, ether, and methane. A two-stage membrane separation system extracts the hydrogen from a CO-rich fuel that fires the cracker (see Fig. 5-3). 

First, the vacuum residue enters (after some preheating) the coker distillation tower, where the products of the cracker are separated into different fractions (gases, gasoline, diesel oil, etc.). The bottom product of the distillation column consists of the vacuum residue (without some lighter compounds, which may still have been present in the residue and which are now separated by distillation) and the heavy recycle oil (about 20% of the cracker products), which also remains liquid in the bottom of the column. This combined liquid heavy oil phase is then pumped through a fired heater to bring the mixture from about 350 °C to the desired heater outlet temperature of about 500 °C. 

Apparent pump failure during startup of propylene unit, fire destroyed unit and damaged catalytic cracker and three storage tanks. 

Since such siting choices are made only rarely the word siting in this chapter also includes decisions to do with the layout of major operating units within a facility. For example, in an oil refinery, the relative locations of units such as the Cat Cracker, Alkylation, and Boiler House can be considered to be siting issues. Once their location has been decided upon, then layout decisions are made with respect to individual equipment items such as distillation columns, heat exchangers, and fired heaters. Regardless of which word is used, many of the issues discussed in this section apply equally well to both. 

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