Lakhasly

1.1.Glass wool can be a loose fill material, blown into attics, or, together with an active binder sprayed on the underside of structures, sheets and panels that can be used to insulate flat surfaces such as cavity wall insulation, ceiling tiles, curtain walls as well as ducting.The cylindrical vesselsare calculated on the principles of thin-walled cylinders.[3]

The first step in designing a container is choosing the best type for the service for which it is intended.Process pressure vessels have multiple and varied uses, among them we can mention heat exchangers, reactors, fractionating towers, distillation towers, etc.Introduction A pressure vessel is considered as any closed vessel that is capable of storing a pressurized fluid, either internal or external pressure, regardless of their shape and dimensions.The factors influencing the choice of type are the function of the container, the location, the nature of the fluid that has to be stored, the temperature and operating pressure and their ability to store the volume needed by the process.[3]

Figure 1.1: Pressure vessel.The former may be horizontal or vertical, and in some cases may have coils to increase or lower the temperature of the fluid.[3]

Figure 1.3: Spherical/ cylindrical pressure vessels.Spherical pressure vessels are usually used as storage tanks, and are recommended for storing large volumes.Pressure vessels can be classified according to their intended service, temperature and pressure, materials and geometry.Different types of pressure vessels can be classified as follows:

Figure 1.2: Pressure vessels classifications.The first classes are only used for storing fluids under pressure, and in accordance with the service are known as storage tanks.According to the intended use of the pressure vessel, they can be divided into storage containers and process vessels.It is also used to insulate piping and for soundproofing.[10]According to the shape, pressure vessel may be cylindrical or spherical.??

1.1. Introduction
A pressure vessel is considered as any closed vessel that is capable of storing a pressurized fluid, either internal or external pressure, regardless of their shape and dimensions. The cylindrical vesselsare calculated on the principles of thin-walled cylinders.[3]

The first step in designing a container is choosing the best type for the service for which it is intended. The factors influencing the choice of type are the function of the container, the location, the nature of the fluid that has to be stored, the temperature and operating pressure and their ability to store the volume needed by the process.[3]

Figure 1.1: Pressure vessel.
Pressure vessels can be classified according to their intended service, temperature and pressure, materials and geometry. Different types of pressure vessels can be classified as follows:

Figure 1.2: Pressure vessels classifications.
According to the intended use of the pressure vessel, they can be divided into storage containers and process vessels.
 The first classes are only used for storing fluids under pressure, and in accordance with the service are known as storage tanks.
 Process pressure vessels have multiple and varied uses, among them we can mention heat exchangers, reactors, fractionating towers, distillation towers, etc.

According to the shape, pressure vessel may be cylindrical or spherical. The former may be horizontal or vertical, and in some cases may have coils to increase or lower the temperature of the fluid.[3]

Figure 1.3: Spherical/ cylindrical pressure vessels.
Spherical pressure vessels are usually used as storage tanks, and are recommended for storing large volumes.
Since the spherical shape is the "natural" form bodies adopt when subjected to internal pressure, this would be the most economical way to store pressurized fluids. However, the manufacture of such containers is much more expensive compared with cylindrical containers.[3]

1.2. Pressure vessel parts
The following two sample vessels are presented: vertical and horizontal. In both cases the main parts are shown:

Figure 1.4: Vertical/Horizontal pressure vessels.

1.3. Types of pressure vessels
The pressure vessels may be classified as follows:
 Horizontal Pressure Vessel.
Horizontal vessels are commonly used as settling drums, surge tanks, reactors and distillate drums. A settling drum is used for phase separation between two immiscible liquids. The L/D ratio of a settling drum is normally four. A surge tank or surge drum is used to maintain a constant flowrate of liquid to a downstream piece of equipment when the flowrate of liquid from the upstream piece of equipment is fluctuating. The fluctuations in flow rate are absorbed by the surge drum by allowing the liquid level in this drum to rise and fall. Horizontal drums are frequently filled with catalyst and used as reactors. Placing catalyst in horizontal vessels allows shallow bed depths and large cross-sectional areas. A typical example of horizontal vessels being used as reactors is the Claus reactor. A distillate or reflux drum provides space for overhead condensable from a distillation column to separate from vapors. Surge drums and distillate drums are normally vertical. If there is settleable water in the feed to these vessels, however, the vessel is erected with a water pot.[1]
The horizontal vessel is a pressure vessel fabricated according to the rules of the specified code (i.e., Section VIII Division 1 of the ASME Code) and erected in the horizontal position. Although the horizontal vessel may be supported by lugs in an open steel structure, the more usual arrangement is for the vessel to be erected at grade and supported by a pair of saddles.[1]
Cylindrical, pressure/vacuum, code design and construction, includes heads, single wall (base material, clad/lined), saddles/ lugs, nozzles and manholes.

 Vertical Pressure Vessel.
Vertical process vessels are typically used as either surge drums or knock out drums. When used as surge drums, they act like shock absorbers, maintaining a constant flowrate of liquid out of the vessel regardless of the flowrate into it. If liquid flows in faster than the constant rate it flows out, the vessel fills with liquid. If liquid flows in slower than the constant rate it is removed, then the liquid level drops. The liquid level is constantly fluctuating in order to absorb these variations in flow and maintain a constant flowrate out. When a vertical process vessel is used as a knock out drum, a mixture of gas and liquid flows into the vessel and this mixture is separated into its gas and liquid components within the vessel. The gas then flows out the top of the vessel and the liquid flows out the bottom.[1]
Vertical process vessels, as their name indicates, are erected in the vertical position. They are cylindrical in shape with each end capped by a domed cover called a head. The length to diameter ratio of a vertical vessel is typically 3:1.
Typically, vertical process vessels hold less than 5000 GALLONS. [1]
Vertical tanks include: process, storage applications liquid, gas, solid processing and storage; pressure/vacuum code design for process and certain storage vessel types; includes heads, single wall, saddles, lugs, nozzles, manholes, legs or skirt, base ring, davits where applicable. [6]

Figure 1.5: Manufacturing sequence of vessels.
1.4. Carbon steel
It is important to clarify the meaning of carbon steel in the generic sense

The term steel is  usually taken  to  mean an  iron-based  alloy  containing  carbon  in amounts  less than about  2%.  Carbon  steels (sometimes  also  termed  plain  carbon steels,  ordinary  steels,  or   straight   carbon   steels)   can   be   defined   as   steels   that contain   only   residual   amounts   of   elements   other   than   carbon,  except  those   (such  as   silicon   and   aluminum)   added   for   De-oxidation   and    those    (such    as   manganese and  cerium)  added  to  counteract   certain   deleterious   effects   of   residual   sulfur. However,  silicon  and  manganese  can   be   added   in   amounts   greater   than   those required strictly  to  meet   these   criteria   so   that   arbitrary   upper  limits  for   these elements have to be set;  usually, 0.60% for silicon and  1.65%  for manganese  are accepted as the limits for carbon steel.[1]

In  some  cases,  requirements   established   by   codes   and   standards   must   be implemented  to  achieve  adequate  results  when working  with  carbon  steels.  It  is important  for the  utility  engineer  to  have  access to metallurgical and  properties information to aid in making decisions for projects involving carbon steels.

1.5. Iso-Butane (2-Methylpropane)
Iso-butane (Butane) is a butane isomer means it contains the same chemical formula as Butane C4H10 but has a different arrangement of its atoms Iso-butane vapor (gas) heavier than air and classified as LPG, together with propane, butane and a group of these gases.[1]
Iso-butane is converted from butane (n-butane) into a process called isomers this process rearranges the atoms in a different molecular configuration. This symmetry occurs in something called a butter unit and includes the use of platinum or another metal catalyst.
` In this process, only some butane is converted to iso-butane, after the butter process, the output mixture passes through a broken or deodorant tower separating the un-converted butane from the iso-butane.[1]
1.5.1-USES OF ISOBUTENE (2-METHYLPROPANE)
 The main use is in refineries, as benzene - gasoline - additive, where it is processed through the alkyl unit to make alkylates.
 It is used to make octane, a high octane gasoline component, which increases the octane rate and anti-knockout properties of gasoline.
 In addition to being used as fuel, iso-butane is commonly used as a coolant and propellant.
 Iso-butane has very low global warming potential and insignificant ozone depletion potential.
 An important use of iso-butane is as a feed stock for plastics. Another use of iso-butane is as a solvent.
 It is used to manufacture propylene oxide for use in making polyurethane plastics.

1.6. n-Butane
n-Butane [C4H10] is a colorless gas with a faint oil-like smell. The main sources of butane are crude oil refinery and natural gas processing. It is commonly blended in gasoline in cars to increase fuel volatility and make starting the engine easier. Butane contains a mixture of methane, ethane, propane, iso-butane and n-butane, a colorless aliphatic hydrocarbon with a gasoline-like odor.[1]
Butane is a component of liquefied petroleum gas (LPG) and is thus used in a wide range of fuel applications for recreational use, including heating, air conditioning, refrigeration, cooking and lighters.
1.6.1-USES OF NORMAL BUTANE ( N-BUTANE )
 n-butane can be used for gasoline blending, as a fuel gas, fragrance extraction solvent, either alone or in a mixture with propane, and as a feedstock for the manufacture of ethylene and butadiene, a key ingredient of synthetic rubber.
 When blended with propane and other hydrocarbons, it may be referred to commercially as LPG, for liquefied petroleum gas. It is used as a petrol component, as a feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays such as deodorants.
 Very pure forms of butane, especially iso-butane, can be used as refrigerants and have largely replaced the ozone-layer-depleting halomethanes, for instance in household refrigerators and freezers.(5)

1.7. Insulation (Glass Wool Fibers)
1.7.1 GLASS WOOL FIBERS :
Glass wool fibers are synthetic or man-made, very small finely spun fibers of glass that form a mass resembling wool. There is considerable variation in the properties of individual fibers within this class, depending on the manufacturing process and end use. They are commonly used for insulation or filtration.
There are generally two categories of glass wool fibers that consumers might use:
low-cost general-purpose fibers and premium special-purpose fibers. Most home and building insulation projects use general-purpose glass wool. Special-purpose glass fibers are used for applications, such as separating the negative and positive plates in a battery, and in high-efficiency air filters and aircraft, pace craft, and acoustical insulation. In general, insulation fibers are less durable and less bio persistent than special-purpose fibers, and may be less likely to cause cancer than the more durable, more persistent special-purpose fibers. [9]
1.7.2. THERMAL INSULATION.
Glass wool is an insulating material made from fibers of glass arranged using a binder into a texture similar to wool. The process traps many small pockets of air between the glass, and these small air pockets result in high thermal insulation properties.
Glass wool is a thermal insulation that consists of intertwined and flexible glass fibers, which causes it to "package" air, resulting in a low density that can be varied through compression and binder content ( these air cells are the actual insulator). Glass wool can be a loose fill material, blown into attics, or, together with an active binder sprayed on the underside of structures, sheets and panels that can be used to insulate flat surfaces such as cavity wall insulation, ceiling tiles, curtain walls as well as ducting. It is also used to insulate piping and for soundproofing.[10]