Pitch, burning

EUREKA pitch is quality pulverized fuel as its characteristics shown in Table 3. The conventional boiler designed for fuel oil can be used for pitch burning as it is. Several Japanese manufacturers had employed EUREKA pitch as boiler fuel. 

Bricks may be extmded or dry-pressed on mechanical or hydraulic presses. Formed shapes may be burned before use, or in the case of pitch or resin/chemically bonded bricks, may be cured (tempered) at a low temperature. 

In the next stage in the recovery and refining of tar acids, water and pitch ate removed from the cmde tar acids in a continuous-vacuum still heated by superheated steam or circulating hot oil. The aqueous phenol overhead distillate is recycled, the stream of once-mn tar acids is refined, and the phenoHc pitch bottoms are burned. 

Other Carbon Products Pitch may be pulverized as a fuel or for other commercial purposes in the former case the unit system of burning is generahy employed, and the same eqiiipment is used as described tor coal. Grinding characteristics vaiy with the melting point, which may be anywhere from 50 to 175°C. 

The numerous process heaters used in refineries to heat process streams or to generate steam (boilers) for heating or steam stripping can be potential sources of sulfur oxides (SO2, and SO3), nitrogen oxides (NO and NO2), carbon monoxide (CO), particulates, and hydrocarbons emissions. When operating properly and when burning cleaner fuels such as refinery fuel gas, fuel oil, or natural gas, these emissions are relatively low. If, however, combustion is not complete, or heaters are fired with refinery fuel pitch or residuals, emissions can be significant. 

The fuel oils coming out of olefin plants are also characterized by an abundance of polynuclear aromatic molecules, (Same definition as for Figure 2—1). They are sometimes inaccurately referred to as having a high aromatics content. Nomenclature aside, because of this, the burning characteristics of pyrolysis gas oil and pyrolysis pitch are poor. They are smoky, sooty, and gum formers they rend to be more viscous, and because of their polynuclear aromatic concent, they are suspected carcinogens. They are basically a witchs brew of unsavory hydrocarbons.. ... 

In the battle of Nice of the 1st Crusade, the Caliphate troops threw burning pitch and fatty balls. They also shot fire arrows with pitch, sulfur and tow from the walls of Jerusalem (Ref 66, p 14)... 

Beside the Bible, the first reliable record of incendiary mixtures was given by the Greek tactician Aeneas, who, at about 350 BC, compiled the. first European treatise on the art of war. He listed sulfur, pitch, pinewood, incense and tow as principal incendiary ingredients Seven centuries later (AD 350), Vegetius, a Roman military authority, added resin, bitumen and petroleum oils to this list which indicates a significant advance in incendiary technique All of these mixtures, however, were of low efficiency because they burned quickly and could easily be extinguished with water... 

A device used as early as the 5th century BC consisted of a hollowed tree and a cauldron with burning coal, pitch and sulfur which were mounted on wheels and brought close the the enemy s wooden fortification. By means of a... 

Romans used the so-called firepot," which was a kind of iron fire bomb (as large as 2 ft in diameter) filled with pitch, sulfur, bitumen, etc and either perforated or latticed so as to permit emission of flames from burning charges. One such bomb may be seen on exhibition in the Tower of London... 

As Black Powder bums comparatively quickly, this shell could not be a satisfactory incendiary missile, unless part of the Black Powder could be replaced by slow burning compounds such as pitch, rosin, sulfur, bitumen, etc, and this was tried... 

Other devices, such as pitch rings and incendiary hoops (Ref 9, p 113) also belong to the surface burning class of munitions... 

A variant of the spherical surface-burning incendiary was the elongated projectile made by kneading a warm incendiary mix over a crossed iron frame which extended to approx twice the length of the desired diam. Typical incendiary components were green pitch, fine corned powd, oakum, tallow, and a small quantity of naphtha. A fuze of fine powd was inserted in the nose to ensure ignition... 

The burning of charcoal by the method still much used of submitting wood to partial combustion in earth-covered mounds is mentioned. The recovery of pitch from resinous trees was either by making incisions in the living tree and collecting the pitch which accumulated, or by a process somewhat similar to the charcoal burning, a process interestingly described by Theophrastus as follows ... 

Carbon pitch is used for carbon electrodes in electrolytic reduction processes, such as aluminum reduction or the production of electro-steels in arc furnaces. Refractory pitch is used in the manufacture of refractory brick, usually burned magnesite or dolomite, the pores of which are filled with pitch by hot impregnation. Upon firing, the pitch in the brick is converted to carbon by carbonization. The remaining pitch coke within the refractory product retards penetration of molten metals and slags, thus prolonging the life of the brick furnace lining. Coke pitch is used in the production of foundry cores. 

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