Horizontal tanks

Single Wall. Single-wall tanks are usually cylindrical and may have either vertical or horizontal orientation. Horizontal tanks are generally supported by two saddle supports and use more space than vertical tanks. Horizontal tanks have an advantage in that leaks can be seen as they occur. 

A partially filled horizontal tank requires the determination of the partial volume of the heads. The Lnkens catalog gives approximate volumes for partially filled (axis horizontal) standard ASME and ellipsoidal heads. A formula for partially filled heads, by Doolittle [Ind. 

FIG. 10-183 Calculation of partially filled horizontal tanks. H = depth of liquid R = radius D = diameter L = length (X = half of the included angle and cosa=l-H/R = l- 2H/D. 

TABLE 10-66 Volume of Partially Filled Heads on Horizontal Tanks ... 

Spheres, spheroids, and toroids use steel or concrete saddles or are suppoi ted by columns. Some may rest directly on soil. Horizontal cyhndrical tanks should have two rather than multiple saddles to avoid indeterminate load distribution. Small horizontal tanks are sometimes supported by legs. Most tanks must be designed to resist the reactions of the saddles or legs, and they may require reinforcing. Neglect of this can cause collapse. Tanks without stiffeners usually need to make contact with the saddles on at least 2.1 rad (120°) of their circumference. An elevated steel tank may have either a circle of steel columns or a large central steel standpipe. Concrete tanks usually have concrete columns. Tanks are often supported by buildings. 

Horizontal-Tank Type This type (Fig. ll-56a) is used to transfer heat for melting or cooking diy powdered solids, rendering lard from meat-scrap solids, and drying divided solids. Heat-transfer coefficients are 17 to 85 W/(m °C) [3 to 15 Btu/(h fF °F)] for drying and 28 to 140 W/(m °C) [5 to 25 Btu/(h fF °F)] for vacuum and/or solvent recovery. 

FIG. 11-56 Heat-transfer equipment for fusion of solids, a) Horizontal-tank type. (Coutiesy of Sttxithers Wells Corp. ) (h) Agitated kettle. (Cowtesy of Read-Standard Division, Capital Products Co.) (c) Donble-dnim mill. (Coutiesy of FaiTel-Bitmingham Co.)... 

FIG. 18-118 Horizontal-tank pressure leaf filter designed for dry cake discharge. Sparkler Filter, Inc.)... 

The main part of the anode slurry, which can contain CaC03, depending on the hardness of the water, is chemically inert from the corrosion point of view, and settles to the bottom of the tank. The slurry must be removed once or twice a week through a stub with a stopcock this takes place in short bursts of opening and closing of the tap at full water pressure. The deslurrying outlet is at the end opposite to the water inlet in a horizontal tank. 

The two types of vessel geometries employed are vertieal and horizontal. In most of the fine ehemieals proeesses the leaves are fitted into vertieal vessels whereas horizontal vessels are used in the heavier process industries sueh as the preparation of sulfur in phosphoric acid plants. The leaves inside horizontal tanks may be positioned either along the tank axis or perpendieular to the axis. In order to utilize the tank volume for maximum filtration area the width of the leaves is graduated so they fit to the eireular eontour of the tank. 

A fireball involving approximately 800 m (28,000 ft ) of isobutane resulted from the sphere s failure. Several BLEVEs of smaller vertical and horizontal tanks occurred soon thereafter. Tank failures were mainly seam-related. Parts were thrown in various directions up to a maximum distance of 135 m (440 ft). 

The blast wave from a cylindrical vessel is weakest along its axis. (See Figures 6.17 and 6.18.) Thus, the blast field is asymmetrical for a vessel placed horizontally. The method will only provide maximum values for a horizontal tank s parameters. 

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. 

The draw-off connection to the oil-burning plant should be at the raised end of horizontal tanks. Where heating... 

Backwashing can be by water alone or by an air scour and water. Usually where high volumes of water are encountered a horizontal type is used because the tank length can be increased proportional to the volume. However, horizontal tanks are restricted to lower levels of suspended solids because of limitations in media bed depth. They are also prone to the risk of the underbed shifting, with a consequential decrease in filtering efficiency. 

A is the area absorbing heat (in ft2) for the following geometries for spheres, 55% of total exposed area for horizontal tanks, 75% of total exposed area for vertical tanks, 100% of total exposed area for first 30 ft, and Q is the total heat input to the vessel (in Btu/hr). 

ULC S601, Shop Fabricated Steel Aboveground Horizontal Tanks for Flammable and Combustible Liquids, covers single-and double-wall cylindrical horizontal steel nonpressure tanks. These requirements do not cover tanks of capacities greater than 200 m . 

Horizontal rectangular cross-section tank. Similarly, required width and length of a horizontal tank of rectangular cross-section can be determined from Stokes Law as ... 

Polyurethane sponge foam. One fabricator offers a coalescer design employing an open-celled polvure-thane foam in a horizontal tank (Fig 4). 

Horizontal tanks. Above ground they are limited to 35,000 gal. Normally they are supported on steel structures or concrete saddles at elevations of 6 to 10 ft. The minimum thickness of shell and heads is 3/16 in. in diameters of 48-72 in. and 1/4 in. in diameters of 73-132 in. 

A horizontal tank installed on the roof of a building used for a blending and packaging operation suddenly exploded, killing two employees. The tank stored a waxy-like material that had a melting point of 212° F (100° C). Each evening an operator recharged the tank for the next day s operation. 

This cylindrical, low-pressure, horizontal tank had a design rating of about 5 psig (0.3 bar). A steam coil heated this tank. The transfer line to the tank was steam traced and insulated to keep it clear, but the heat tracing and insulation system on the inlet transfer piping was less than ideal. The inlet piping had to be dismantled on several occasions to clear it because of solidification in the fine. (See Figure 6—18.) [7]... 

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