Layout drums

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. 

A design pressure of 545 kPa, gage is normally specified for water disengaging drums. The water outlet system is designed to seal the drum and prevent entrainment of hydrocarbon or air into the sewer. Figure 5 indicates the normal layout incorporating a single loop seal. 

Piping to Burners - First and second stage piping and headers, as well as the burner lines themselves, are sized to minimize pressure drop and velocity effects. Thus, maldistribution of flow to the burners will be minimized. The burner lines are fabricated from standard 1(X) mm pipe, and are arranged in a split grid layout with distribution headers and split feed lines on opposite sides, for both first and second stage burners. First and second stage headers must be sloped so that any condensate will drain back to the seal drums. However, the burner lines must be accurately installed in a horizontal plane. 

Based on the layout spacing, select a drum length of 6 ft, 8 in. + 2 (2 ft overhang) = 10 ft, 8 in. overall length (approximate, to be adjusted on final detail drawing). The new diameter corresponding to this length is... 

The equipment layout must be devised to ensure proper circulation of acid, not only from drum to drum, but also from the headers. This may require additional pumps, the use of a manifold, or the moving of hoses from one leg to another. 

It was noticed that the order of process items in the layout spacing recommendations is almost identical. The furnaces and fired heaters are on the top of the list (see Table 18). The next group is formed by compressors and high hazard reactors. Air coolers, ordinary reactors and high hazard pumps appear next. After that come towers, process drums, heat exchangers and pumps. The last and safest group is formed of equipment handling nonflammable and nontoxic materials. 

Figure 7.18a shows a typical layout of a rotary drum installation and Figure 7.18Z shows the sequence of cake formation, washing and dewatering. A large rotary drum vacuum filter is shown in Figure 7.19. 

Figure 7.18. Typical layout of rotary drum filter installation...

Space needs to be provided for the auxiliaries, including the lube oil and seal systems, lube oil cooler, intercoolers, and pulsation dampeners. A control panel or console is usually provided as part of the local console. This panel contains instruments that provide the necessary information for start-up and shutdown, and should also include warning and trouble lights. Access must be provided for motor repair and ultimate replacement needs to be considered. If a steam turbine is used, a surface condenser is probably required with a vacuum system to increase the efficiency. All these additional systems need to be considered in the layout and spacing. In addition, room for pulsation dampeners required between stages has to be included. Aftercoolers may also be required with knockout drums. Reference 8 describes the requirements of compressor layouts and provides many useful piping hints. 

Figure 1.2 Layout of azo dye manufacturing plant. 1, storage tanks for liquid starting materials 2, storage drums for solid starting materials 3, diazotisation vessel 4, coupling component vessel 5, ice machine 6, coupling vessel 7, isolation vessel 8, filter presses 9, filtrate to waste liquor treatment plant 10, dryers 11, emptying of dyestuffs for feeding to the mill 12, outgoing air purification plant.

The blender may need to fit within an existing plant, so layout considerations often come into play. This includes not only the height and footprint consumed by the blender, but also additional operations such as fitting an IBC underneath a blender to receive the blend, and methods to load the blender initially. The headroom available beneath a blender may affect the choice of IBC (e.g., drums, steep conical hopper, shallow pyramidal hopper), which can ultimately affect segregation and content uniformity. Having a layout that allows ease of peripheral operations such as cleaning, inspection, and... 

Figure 369. Schematic representation of the layout of a rotary drum coater (Hi-Coater) with a batch size of approximately 200 kg ...

Fig. 9.1 The Schematic Layout of the FCC Feed Surge Drum (72SD1).

The schematic layout of the FCC feed surge drum (72SD1) considered in this work is illustrated in Fig. 9.1. Altogether, there are a total of 7 different feed streams ... 

For plant layout, in addition to tower sequence, every equipment item has an optimum location for minimum pipe runs. For exchanger, drum and pump locations the following general classifications can be made. 

Multiple-drum dryers for handling loose stuff may be arranged with rotating cylinders in a horizontal or vertical array, although the former is more common. The vertical arrangement has advantages if the material has to be shifted from one level to another. A comparison in layout between brattice and suction-drum dryers is shown in Figure 37.7. 

Drums will normally be received in 80 drum loads with occasional loads of up to 100 drums and a storage layout which allows for access around such a load for inspection for leakage, stocktaking, etc., is desirable. 

Figure 8.2 Typical layout of parallel-flow drum-mix plant for hot mix asphalt. (From EAPA and NAPA, The Asphalt Paving Industry A Global Prospective, 2nd Edition, GL 101. Brussels EAPA, 2011 Courtesy of National Asphalt Pavement Association, http //www.asphaltpavement.org.)...

It may be noted that the periphery of the open end of the tank was circular to facilitate sealing and also this aperture was eccentric to the drum axis so as to allow space for the heater. The general layout is shown in Fig. 9.1. 

When specified, steam drums and deaerators are usually furnished as a proprietary item. Layout is limited to confirmation of nozzle and support locations to suit piping and structural configurations and platforming for operator and maintenance access. Exhibit 5-3 illustrates a typical deaerator arrangement. 

The first step in drum layout is setting the height of the drum. To do this, the plant layout designer requires the following information ... 

Exhibit 7-43 also shows the product outlet line and its decoking hook-up. Line A is set up in its usual operation configuration line B is set in the decoking mode. As the steam and air are blown through the radiant tubes, any waste is carried to the sewer or, if preferred, to a drum for removal. The vent line is run to the stack. Once again, the plant layout designer... 

Exhibit 12-27 illustrates two r ations of the structure generally found In a coker unit. As can be seen, the main operating valve platform is the only platform supported from the elevated concrete de in both arrangements. In one variation, the operator s penthouse is supported from the tqp of tte vessel, along with the entire drill struaure above the penthouse. This layout requires the coke drums to be designed to... 

In Exhibit 12-17, the exchanger is set above die drum as in the previous design, but it is supported in a completely different manner. By consulting with the vessel engineer, the plant layout designer may be able to support the exchanger and platform from the vessel shell as shown, with the drum supported from concrete piers. This application should be considered whenever it is economically practical. 

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