Vertical vessel calculation

The general format of the Vertical vessel calculation is presented in Figure 1.24. General data entry and calculation principles are as discussed for the horizontal vessel calculation. However, the following points should be considered ... 

Minimum work for an ideal separation at first glance appears unrelated to the slender vertical vessel having a condenser at the top and a reboder at the bottom. The connection becomes evident when one calculates the work embedded in the heat flow that enters the reboder and leaves at the condenser. An ideal engine can extract work from this heat. 

Figure 4.10 displays a typical vertical vessel program run printout. The program calculation output gives a minimum required diameter. This diameter is based on the terminal velocity of liquid drop fall velocity, gas bubble in oil rise velocity, or the water drop fall velocity. The smaller this terminal velocity, the greater the vessel cross-section area required and thus the greater the vessel diameter required. In this example, the oil-phase gas bubble rise terminal velocity is controlling. If you reduce the oil flow to, say, 10,000 lb/h, then the gas-phase liquid... 

THREE PHASE VERTICAL VESSEL ANALYSIS CALCULATIONS... 

THREE PHASE VERTICAL VESSEL ANALYSIS CALCULATIONS Gas - Oil - Water Separation... 

The stresses produced in a self-supporting vertical vessel by the action of the wind are calculated by con dering the vessel to 1 a verticle, uniformly loaded cantilever beam. The wind loading is a function of the wind veloirfty, air density, and the shape of the tower. The Unip States Weather Bureau (137) has correlated Uie above factors in the following relation ... 

EXAMPLE DESIGN, SHELL CALCULATIONS FOR A TALL VERTICAL VESSEL... 

Example Design, Shell Calculations for a Tall Vertical Vessel T75... 

Rolled-anole Beahimg Plate. If the vertical vessel is not very high and a skirt is used to support the vessel rather than le, lugs, or columns, a simple design may suffice for the bearing plate. If the calculated thickness of the bearing plate is in. or less, a st l angle rolled to lit the outside of the skirt may he lap welded as shown in Fig. 10.3. 

Anchors need not be designed for shear if it can be shown that the factored shear loads are transmitted through frictional resistance developed between the bottom of the base plate and grout at the top of the concrete foundation. If there is moment on a base plate, the moment may produce a downward load that will develop frictional resistance even if the eolumn or vertical vessel is in uplift, and this downward load ean be eonsideied in calculating frictional resistance. Care should be taken to assure that the downward load that produces frictional resistance occurs simultaneously with the shear load. 

The vessel.exe program has been developed to estimate the total and filled-liq-uid volumes and dry and wet surface areas for horizontal, vertical, and inclined (e.g., slug catcher) vessels. For horizontal and vertical vessels, the program also calculates the weight of the material and the hydro test weight. 

A. Solid particles suspended in agitated vessel containing vertical baffles, continuous phase coefficient -2 + 0.6Wi f,.Wi D Replace Osi p with Vj = terminal velocity. Calculate Stokes law terminal velocity [S] Use log mean concentration difference. Modified Frossling equation K, -< T.d,P. [97] [146] p.220... 

The wetted area of the tank or storage vessel shall be calculated as follows For spheres and spheroids, the wetted area is equal to 55 percent of the total surface area or the surface area to a height of 30 feet (9.14 meters), whichever is greater. For horizontal tanks, the wetted area is equal to 75 percent of the total surface area For vertical tanks, the wetted area is equal to the total surface area of the shell within a maximum height of 30 feet (9,14 meters) above grade. 

Calculation methods are given here for cases (a) to (c). In section A3.4 below, references are given to a calculation method for case (d). The level swell calculation methods presented here use the drift flux correlations developed by DIERS[11. The DIERS correlations apply to a vertical cylindrical vessel, which is most often the case for chemical reactors. Modifications for horizontal cylindrical vessels are given by Sheppard[2,3]. 

The program next calculates the gas phase area and finally the length of vessel required for the drop separation with the given diameter. The user selects a diameter as a data input. Another key selection by the user is the water and oil depths. Please note that these are discrete vertical measures taken at the center of a cylindrical vessel. The water depth and oil depth, in, is to be added by the program to find the total liquid depth. Herein the user should consider the instrumentation requirements to achieve good level control. 

An electric technique to measure the gas holdup was implemented by Linek and Mayrhoferova (1969). In this method, the surface elevation of the gas-liquid interface of the nonaerated and aerated liquid in the vessel is detected at certain selected points by means of an electrical probe. The height is determined by the vertical position of the probe at which the sum of contact times equals one-half of the measurement period. The gas holdup is then calculated from the total surface elevation, the cross-section of the reactor, and the liquid volume. The accuracy of the measured value of the total surface elevation is claimed by the authors to be +0.2 mm. 

To account for the extra weight due to nozzles, manholes, and skirts or saddles, increase the weight calculated for the smooth vessel including top and bottom by 1.5% for vessels to be installed in a horizontal position and by 20% for vessels to be installed in a vertical position. 

Platikanov et al. [108-111] have developed a measuring cell which can be used not only in the measurement of the electrical conductivity but also in the calculation of transference numbers of ions in black films. Two cylindrical hollow electrodes made of silver 1 (Fig. 2.17) are situated coaxially one over the other. The lower electrode is placed in a Teflon vessel 3 in which the solution is poured. The upper electrode can move vertically by a precise micrometric system. Ring 2 made of a porous glass is placed on each electrode. 

A. Solid particles suspended in agitated vessel containing vertical baffles, continuous phase coefficient A = 2 + 0.6N tNS Replace vz [p with uT = terminal velocity. Calculate Stokes law terminal velocity c d lp,-pjg K 18 ic and correct 1 10 100 1,000 10,000 100,000 [S] Use log mean concentration difference. Modified Frossling equation = Vn "P ° Re (Reynolds number based on Stokes law.) V -vTdrP° A Re,r — (terminal velocity Reynolds number.) kl almost independent of dp. Harriott suggests different correction procedures. Range ki/k is 1.5 to 8.0. [74] [ 138] p. 220-222 [110] [74]... 

In a recent work, Aiba (A2) studied the flow currents in water, in a mixing vessel 14 in. in diameter, using an axially-mounted two-bladed flat paddle 4.7 in. in diameter. Measurements were made both without baffles and with four baffles %2 tank diameter wide. A sphere about 6 mm. in diameter was suspended by a flexible wire, and its displacement from the equilibrium (no-flow) position was measured. To get the horizontal displacement, cobalt-60 was embedded in the sphere, and a Geiger-Mueller counter approximately 10 mm. in diameter was immersed in the tank 2-5 cm. from the sphere. The vertical movement of the sphere was measured with a cathetometer, and its angular position observed by eye. From the known components of displacement and the assumed drag coefficient of the sphere, values of the radial, tangential, and vertical components of the flow around the sphere were calculated. 

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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