Cylindrical pressure vessels

The experimental activity was carried out on a cylindrical pressure vessel whose capacity is 50 litres and made from steel 3 mm thick. Fig. 2 shows the layout of the pressure vessel considered. The pressure vessel was connected to an oil hydraulics apparatus providing a cyclical pressure change of arbitrary amplitude and frequency (fig.3). Furthermore the vessel was equipped with a pressure transducer and some rosetta strain gauges to measure the stresses on the shell and heads. A layout of the rosetta strain gauges locations is shown in fig.4. 

Thermal Stresses. When the wak of a cylindrical pressure vessel is subjected to a temperature gradient, every part expands in accordance with the thermal coefficient of linear expansion of the steel. Those parts of the cylinder at a lower temperature resist the expansion of those parts at a higher temperature, so setting up thermal stresses. To estimate the transient thermal stresses which arise during start-up or shutdown of continuous processes or as a result of process intermptions, it is necessary to know the temperature across the wak thickness as a function of radius and time. Techniques for evaluating transient thermal stresses are available (59) but here only steady-state thermal stresses are considered. The steady-state thermal stresses in the radial, tangential, and axial directions at a point sufficiently far away from the ends of the cylinder for there to be no end effects are as fokows ... 

Spiral-wound cartridges are inserted ia series into cylindrical pressure vessels. Feed flows parallel to the membrane surfaces ia the channel defined by the mesh spacer which acts as a turbulence promoter. Permeate flows into the center permeate-withdrawal tube which is sealed through the housing end caps. 

Pulsed beds of ac tivated carbon are used in water and wastewater treatment systems. The adsorber tank is usually a vertical cylindrical pressure vessel, with fluid distributors at top and bottom, similar to the arrangement of an ion exchanger. The column is filled with granular carbon. Fluid flow is upward, and carbon is intermittently dis-... 

The longitudinal stress ct in the wall of a cylindrical pressure vessel containing gas at pressure p is given by... 

The supersonic wind tunnels in the Aerodynamic Laboratory at Cambridge University are powered by a bank of twenty large cylindrical pressure vessels. Each time the tunnels are used, the vessels are slowly charged by compressors, and then quickly discharged through a tunnel. How should we go about designing and checking pressure vessels of this type to make sure they are safe ... 

Fig. 16.6. Design against yield and fast fracture for a cylindrical pressure vessel.

The failure took place in a large water-tube boiler used for generating steam in a chemical plant. The layout of the boiler is shown in Fig. 13.1. At the bottom of the boiler is a cylindrical pressure vessel - the mud drum - which contains water and sediments. At the top of the boiler is the steam drum, which contains water and steam. The two drums are connected by 200 tubes through which the water circulates. The tubes are heated from the outside by the flue gases from a coal-fired furnace. The water in the "hot" tubes moves upwards from the mud drum to the steam drum, and the water in the "cool" tubes moves downwards from the steam drum to the mud drum. A convection circuit is therefore set up where water circulates around the boiler and picks up heat in the process. The water tubes are 10 m long, have an outside diameter of 100 mm and are 5 mm thick in the wall. They are made from a steel of composition Fe-0.18% C, 0.45% Mn, 0.20% Si. The boiler operates with a working pressure of 50 bar and a water temperature of 264°C. 

Zick, L. P., Stresses in Large Horizontal Cylindrical Pressure Vessels on Two Saddle Supports, Welding Journal Research Supplement, 1951. 

A filament wound composite cylindrical pressure vessel has a diameter of 1200 mm and a wall thickness of 3 mm. It is made up of 10 plies of continuous glass fibres in a polyester resin. The anangement of the plies is [O3/6O/ — 60],. Calculate the axial and hoop strain in the cylinder when an internal pressure of 3 MN/m is applied. The properties of the individual plies are... 

Old vessels may not be as cheap as they seem at first sight. Nozzles and manways are often in the wrong plaee, and the eost of modifying them may make the vessel more expensive than a new one. A designer who was persuaded to use an old cylindrical pressure vessel ended up using the two dished ends and nothing more ... 

The general procedure of the basic method is shown in Figure 6.20. This method is suitable for calculations of bursts of spherical and cylindrical pressure vessels which are filled with an ideal gas, placed on a flat surface, and distant from other obstacles which might interfere with the blast wave. 

The vessel is determined to be an uninsulated, horizontal, grade-level, cylindrical pressure vessel with a gas volume of 706 ft3 (20 m3). The vessel has a MAWP of 1,480 psig (102 bar) at 650°F (343°C) and a Minimum Design Metal Temperature (MDMT) of 40°F (4°C) since it is constructed of unnormalized steel material. Due to process conditions immediately prior to pressuring the vessel to 1,000 psig (69 bar), the vessel s metal temperature is approximately 30°F (-1°C). When the vessel is pressurized to 1,000 psig, it fails catastrophically. The distances to overpressure endpoints (1, 3, and 5 psig) are calculated as follows ... 

Zick, L. P. (1951) Welding J. Research Supplement 30, 435. Stresses in large horizontal cylindrical pressure vessels on two saddle supports. 

Suppose you wanted to find the configuration that minimizes the capital costs of a cylindrical pressure vessel. To select the best dimensions (length L and diameter D) of the vessel, formulate a suitable objective function for the capital costs and find the optimal (LID) that minimizes the cost function. Let the tank volume be V, which is fixed. Compare your result with the design rule-of-thumb used in practice, (L/D)opt = 3.0. 

The ideal shape of a pressure vessel is spherical. Ho vever, for technical reasons cylindrical pressure vessels are often preferable (Figure 5.4). 

Figure 5.4 Schematic representation of a cylindrical pressure vessel and calculation of the radial, longitudinal and tangential stress.

MODAR Inc. (Massachusetts. USA) developed the first reactor vessel [13]. It comprised an elongated, hollow cylindrical pressure-vessel, capped at both ends so as to define an interior reaction chamber. Defined within the reaction chamber are a supercritical temperature zone, in the upper region of the reactor vessel, and a subcritical temperature zone in the lower region of the reactor vessel. Oxidation of organics and oxidizable inorganics takes place in the supercritical temperature zone. Dense matter, such as inorganic material initially present and formed by reactions, if insoluble in the supercritical-temperature fluid, falls into the liquid phase provided in the lower-temperature, subcritical zone of the vessel. A perimeter curtain of downward-flowing subcritical-temperature fluid is established about a portion of the interior of the cylindrical wall of the vessel to avoid salt-deposits on the walls of the reactor vessel. 

Figure 18.17. Types of heads for cylindrical pressure vessels, (a) Flat flanged KR = knuckle radius, SF= straight flange, (b) Torispherical (dished), (c) Ellipsoidal, (d) Spherical, (c) Conical, without knuckle, (f) Conical, with knuckle, (g) Nonstandard, one of many possible types in use.

Pressurizer. The pressurizer is a cylindrical pressure vessel, vertically mounted and bottom supported. Energy to the water is supplied by replaceable direct-immersion electric heaters, which are inserted from the bottom head of the pressurizer. Nozzles are provided for spray, surge,... 

Reforming in the CRG process occurs adiabatically at 450-550 C at pressures up to about 600 psig (41 atmospheres). The reactor is a vertical cylindrical pressure vessel containing a bed of the special high-nickel catalyst which is supported on a grid or on inert ceramic halls. The gas flow is downwards through the bed and distributors are provided at inlet and outlet. A layer of ceramic balls on top of the bed prevents disturbance of the catalyst by the entering gas. 

Fractionation, by definition, is simply the mass transfer between a liquid phase and a gas phase in contact with each other. A fractionation column is simply a tall, vertical, cylindrical pressure vessel that contains numerous flat internal metal plates called trays. Each tray allows liquid to flow over it, so the liquid flows from tray to tray by the force of gravity. The liquid thus enters the top tray. The liquid portion not vaporized in the column s trays is taken out in the column s bottom liquid accumulation. Gas enters the column s bottom section and flows through each tray to the top section. Entering vapor pressure is its driving force. Gas not absorbed by the liquid exits the column s top section. 

Pressure storage at ambient temperature in spherical or cylindrical pressure vessels having capacities up to about 1500 tonnes. 

Modem three layers pressure vessels are under study, which consist of a stressbearing component - an inner polymer liner over-wrapped with a carbon-fibre composite - and an outer aramid-material layer, mechanical and corrosion damage resistant [1]. A system for the gaseous hydrogen storage at room temperature has also been designed, adopting a definite number of linked cylindrical pressure vessels [13]. 

Gases are stored at atmospheric pressure in wet- or dry-seal gas holders. The wet-gas holder maintains a liquid seal of water or oil between the top movable inside tank and the stationary outside tank. In the dry-seal holder the seal between the two tanks is made by means of a flexible rubber or plastic curtain. Recent developments in bulk natural gas or gas-product storage show that pumping the gas into underground strata is the cheapest method available. High-pressure gas is stored in spherical or horizontal cylindrical pressure vessels. 

Usually, cylindrical pressure vessels are designed for about 2.5 MPa. The larger spherical vessels are designed only for about 1.6 MPa to avoid wall thicknesses above 30 mm. A coat of reflecting paint or, frequently in hot climates, an outer covering of insulation may be used on the vessels to avoid solar radiation heating. Spraying the... 

A vertical cylindrical pressure vessel is I.O m In diameter and 3.0 ni in height. Its outside average wall temperature is 60 C, while the surrounding air is at O C, Calculate the rale of heat loss from the vessel s cylindrical surface when there is (a) no wind and (h) a crosswind of 20 km/h. 

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