Vessel tangent line

The inlet and outlet nozzles shall be located as closely as practical to the vessel tangent lines. Liquid outlets shall have anti-vortex baffles. 

A typical horizontal three-phase separator with flooded weir is shown in Figure 3.4. The inlet nozzle (Nl) and the gas outlet nozzles (N2) are placed as close as possible to the vessel tangent line. The distance of tiie nozzle center line and the tan line is dictated by tiie mechanical limitations of the vessel however, distances in Table 3.7 can be used for initial design. 

Cyclone Separator with Integral Catch Tank (See Fig. 26-19.) The diameter of the knockout drum is calculated by the criteria given in the preceding section and Fig. 26-18. Since the liquid is also to be retained in the vessel, extend the shell height below the normal bottom tangent line to increase the total volume by an amount equal to the volume of the hquid carried over. 

When a small quantity of a second liquid phase is present, a drawoff pot (commonly called a bootleg) is provided to make separation of the heavy liquid (frequently water) easier. The pot diameter is ordinarily determined for heavy phase velocities of 0.5 ft/min. Minimum length is 3 ft for level controller connections. Minimum pot diameter for a 4-8-ft diameter reflux drum is 16 in. For reflux drums with diameters greater than 8 ft, pot diameters of at least 24 in. are used. The pot must also be placed at a minimum distance from the tangent line that joins the head with the body of the vessel. 

Wb = weight of vessel at base, lb W, = weight of vessel at tangent line, lb w — width of base plate, in. 

Step 9 Check vessel with lateral load, Fp, applied at the top tangent line of the vessel. If the stresses are acceptable, the vessel is OK. If the stresses are not acceptable, then the thicknesses must be revised until the stresses are acceptable. 

Lu = laterally unsupported length for a free-standing vessel, for a skirt-supported vessel with no guide wires, the distance is from the top tangent line to the base of the skirt, in. 

Determine the maximum allowable vacuum that can be applied to a low-carbon-steel cylindrical vessel 10 ft in oittside diameter with elliptical dished heads k = 2.0). The head and shell thickness are both in., and the vessel is 30 ft long Uangent line to tangent line). 

For the vessel in problem 1, calculate the rnaxitrium. stre.ss at the bottom tangent line resulting from the, seismic moment. 

A 12-in.-insidfs-diameter pressure vessel is fabricated of an iiiiu r. shell of copp r 1 in. thick and an outer shell of steel in. thick in such a manmir that the inUd fact f res.sure is /xtro and the two shells are in contact with each other. The reactor is 4 ft long from tangent litu to tangent line with ellipsoidal heads (also of double layer). 

Calculation of working volume for a horizontal cyhndrical vessel is more complex. Firstly we have to calculate the volume (Vq) between the bottom of the vessel and the 0 % level indication. The length of the vessel (1) is that measured between tangent lines - the point where any dished ends are welded to the vessel. The last term in Equation (4.3) determines the volume of Hquidheld in the dished ends. It assumes a 2 1 ratio between drum radius and depth of each dish. It should be omitted if the vessel has flat ends. 

The preferred location for level instruments is away from the turbulence at the liquid outlet nozzle. Although the vessel is provided with a vortex breaker, instruments should be set in the quiet zone of the vessel for example, on the opposite side of the weir or baffle or near the vapor outlet end. Process nozzles should be located a minimum from the tangent line. Steam-out conneaions should be located at the end opposite the maintenance access and vent in the bot-... 

An example of how to deal with a typical NPSH problem Ls shown in Exhibit 8-2. The required NPSH in this example is 22 ft (6,700 mm). If a horizontal pump is used, the bottom tangent line of vessel A must be a minimum of 22 ft (6,700 mm) above the centerline elevation of the shaft. If a vertical pump is used, the... 

Tower elevation is the distance from grade to the bottom tangent line of the vessel. Suppon is the means by which the vessel is retained at the required elevation. Exhibit 10-11 shows an example of elevation and support. 

In steel or alloy vessels, the recommended baffle design for solid suspension of settling solids is four flat blade baffles, each with width, B, equal to T/12 at a wall clearance of at least T/72. The baffles should extend to the lower edge of the lower impeller or to the lower tangent line. 

L = length of vessel between tangent lines (in.) r = radius of vessel (in.) t — thickness of shell (in.)... 

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