Fired heaters construction

The two governing modes of heat transfer in the construction of a fired heater are radiation and convection. 

The petroleum feedstocks that contain sulfur as an impurity are handled under ambient conditions in carbon-steel tanks and pipelines where the corrosion attack by sulfur is less severe. In the desulfurization step, vaporized feedstock is processed at 400°C in the presence of hydrogen sulfide (H2S) and carbonyl sulfide (COS) - both of which are highly corrosive. Stainless Steels (SS) 304, 316 or 321 (for the fired heater) are used as the material of construction for various pieces of process equipment in this section of the plant. Equipment failures occur because of external corrosion and thinning of fired-heater coils and interior deposition of carbon from coking which leads to overheating. Fuel-gas lines, that contain hydrocarbon vapors and H2S, should be constructed of SS 304 and heat traced to avoid condensation88. 

Pyrolysis furnace. This unit also performs two operations It preheats the vapor to its reaction temperature, 500°C, and it carries out the pyrolysis reaction. The unit is constructed of refractory brick, with natural gas-fired heaters, and a large bundle of Nickel, Monel, or Inconel tubes, within which the reaction occurs. The tube bundle enters the coolest part of the furnace, the so-called economizer at the top, where the preheating occurs. 

Gas-fired water heaters use the same general method of construction, except that the elements are replaced with a burner beneath the tank. The combustion products from the burner are vented through a flue made out of the same thickness steel as the tank, that goes up through the center of the tank. To increase heat transfer from the hot flue gases to the inner wall of the flue, a baffle is inserted down the flue. This baffle is a twisted strip of sheet metal with folds and tabs on it. The folds and tabs are designed to... 

The most common type of commercial pyrolysis equipment is the direct fired tubular heater in which the reacting material flows through several tubes connected in series. The tubes receive thermal energy by being immersed in an oil or gas furnace. The pyrolysis products are cooled rapidly after leaving the furnace and enter the separation train. Constraints on materials of construction limit the maximum temperature of the tubes to 1500 °F. Thus the effluent from the tubes should be restricted to temperatures of 1475 °F or less. You may presume that all reactor tubes and return bends are exposed to a thermal flux of 10,000 BTU/... 

RCF is sold in a variety of forms, such as loose fiber, blanket, boards, modules, doth, cements, putties, paper, coatings, felt, vacuum-formed shapes, rope, braid, tape, and textiles. The products are principally used for industrial applications as insulation in furnaces, heaters, kiln linings, furnace doors, metal launders, tank car insulation, and other uses up to 1400°C. RCF-consuming industries indude ferrous and nonferrous metals, petrochemical, ceramic, glass, chemical, fertilizer, transportation, construction, and power generation/incineration. Some newer uses include commercial fire protection and applications in aerospace, eg, heat shields and automotive, eg, catalytic converters, metal reinforcement, heat shields, brake pads, and airbags. 

This oil mist caught fire by contacting either a flame on a water heater or the flame of a bellows heating coke for steel plate riveting. Beside the oil spill from the roof, oil flowed from ruptures of the outlet and inlet pipes at the bottom of the tanks. Huge quantities of burning oil rushed down the slope into the naval port. The warships anchored in the port withdrew hurriedly. Based on this experience, circular tanks were constructed and buried in the ground to replace the steel tanks that were ruptured 40). ... 

An in-sack dryer is made of a platform that contains holes just large enough to hold jute sacks full of grain. Heated air is blown up through the holes (and grain) via a heater or fan unit. The platform may be constructed from locally available material. A typical oil-fired unit that deals with 2-5 tons of grain is equipped with a fan that delivers 9700 mVh of air heated to 14°C above ambient temperature and consumes about 4.5 L of oil per hour [8]. For 2-ton loading, the moisture removal rate is about 1% per hour. 

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