Headers inlet

A basic PAFC stack configuration is given in Fig. 13. The anode-acid holder matrix-cathode sandwich is held between two bipolar plates and this array is repeated to the end. At each end there is an one-side grooved plate—one with anode groove and the other end with cathode groove. Each of these plates have through holes, when assembled act as reactant gas flow headers (inlet and outlet). The inlet header of one gas has an opening in one side of each bipolar plate, and similarly the outlet header of the same gas collects excess unreacted reactants/products from the same side of the bipolar plates. The inlet and outlet headers of the other gas similarly feed and collect gas from the other side of the bipolar plates. 

Cylindrica.1 Element Filters. These filters, often referred to as candle filters, have cylindrical elements or sleeves mounted vertically and suspended from a header sheet, which divides the filter vessel into two separate compartments (Fig. 16). The filtration takes place on the outside of the sleeves. The inlet is usually in the bottom section of the vessel and the filtrate oudet in the top section above the header sheet. A less usual design is to locate the filtrate outlet at the bottom of the elements and thus allow the top chamber to be opened for each inspection of the elements during operation. 

A numerical study of the effect of area ratio on the flow distribution in parallel flow manifolds used in a Hquid cooling module for electronic packaging demonstrate the useflilness of such a computational fluid dynamic code. The manifolds have rectangular headers and channels divided with thin baffles, as shown in Figure 12. Because the flow is laminar in small heat exchangers designed for electronic packaging or biochemical process, the inlet Reynolds numbers of 5, 50, and 250 were used for three different area ratio cases, ie, AR = 4, 8, and 16. 

The flow distribution in a manifold is highly dependent on the Reynolds number. Figure 14b shows the flow distribution curves for different Reynolds number cases in a manifold. When the Reynolds number is increased, the flow rates in the channels near the entrance, ie, channel no. 1—4, decrease. Those near the end of the dividing header, ie, channel no. 6—8, increase. This is because high inlet velocity tends to drive fluid toward the end of the dividing header, ie, inertia effect. 

Four magnetite rod anodes (All to A14), each weighing 9 kg, in perforated polypropylene protection tubes were used to protect the box headers, the in-flow hood and inlet housing as well as the CrNi steel oil cooler. Protection tubes keep out solid matter carried in the river water. The oil cooler was connected to the protection equipment with its own cathode conductor. 

D = Header diameter, ft f = Moody friction factor L = Header equivalent length, ft M2 == Mach number at the header outlet Pi,P2 = Inlet and outlet header pressures, psia... 

Flush inlet headers, laterals, and return lines Drain to prevent freezing Clean tower basin Adjust tower fans Service Air... 

Mak used the same Lapple article to develop a method for designing flare headers. His method has the advantage of starting calculations from the flare tip (atmospheric) end, thus avoiding the trial and error calculations of methods starting at the inlet. 

Flow Meter Orifice Plate - A flow meter orifice plate is permissible in normal process flow pressure reheving path, provided that it can pass the required emergency flow without exceeding pressure limits of the upstream equipment. However, it is not acceptable in PR valve inlets and flare headers. 

A check valve is not, however, permissible in PR valve inlet or outlet piping, or in any flare or safety valve header. 

This section describes the requirements for the design and installation of pressure relief valve inlet and outlet piping manifolds and valving, including safety valve and flare headers. 

It is important to note that even if the blowdown is effective in disengaging liquid and vapor, further condensation could occur downstream especially if the vented vapor exits the drum at a temperature above ambient conditions. A proportion of such condensible materials in the blowdown drum vapor release may condense as a result of cooling in the flare header and contact with seal water, and then disengage in the flare seal drum while condensible vapors which are not condensed out at this stage may condense in the flare stack or its inlet line, thus creating the potential for hazardous fallout of burning liquid from the flare. Condensed hydrocarbon in the seal drum can be entrained out with the... 

A typical non-condensible blowdown drum and its associated equipment and headers are illustrated in Figure 1. A single blowdown drum may be used for more than one process unit, if economically attractive. However, when this is done, all units served by it must be shut down in order to take the drum out of service, unless cross connections are made to another system of adequate capacity. Normally all closed safety valve discharges are combined into one header entering the drum, although separate headers and inlet nozzles are acceptable if economically advantageous. The following releases are also normally routed into the safety valve header ... 

An important design detail is that the inlet line should be sloped at least 30" from the horizontal and the diameters of the vertical and sloped legs of the Y-seal are sized such that a 3 m slug of water is pressured back up the sloping inlet line, without spilling over into the header, in the event of flashback. Note that this requires an enlarged diameter section in the vertical leg of the Y-seal. The seal is maintained by a continuous flow of water at 1.26 dm /s and the water makeup is provided with steam injection, if required for winterizing or cold releases. 

Example The maximum flare load of a system is 1,000,000 Ibs/hr of vapor. The pressure at the base of the flare stack is 2 psig, the average molecular weight of the vapor is 50, at a temperature of 200°F at the combined header to the flare stack. The distance from the drum to the stack is 500 ft. The line consists of two 90° welding elbows and an orifice for a flow controller. The total pressure drop at the knock-out drum is 0.5 psi. Determine the pressure at the inlet of the knock-out drum. 

Less l ow flow Valve V-19 partially closed HF Vaporizer inlet header partially phijiv.ed/frozen Insufficient HF supply to B-1 process, consequences unknown No known protection 3 Same as Scenam) i... 

The Loss of Heat Sink has three subclasses total loss of primary system circulation (5%), los,s of secondary cooling from effluent header failures (1 %), and total loss of secondary cooling from inlet... 

Superheater elements are connected to inlet and outlet headers. The inlet header receives dry saturated steam from the steam drum of a watertube boiler or the shell of a horizontal boiler. This steam passes through the elements where its temperature is raised and to the outlet header which is connected to the services. A thermometer or temperature recorder is fitted to the outlet header. 

The wet steam passes through steam-water separators within the top drum. Separated water is returned to the inlet of the external downcomer, while the moist-to-dry steam may pass through a secondary steam-water separator to remove any residual moisture before passing into the steam header part of the steam delivery system. 

Closed FW heaters are shell and tube heat exchangers typically designed to contain U-tube bundles expanded or welded into a single, stationary tube sheet (although some designs replace the tube sheet with inlet and outlet box headers). 

Particularly critical areas for corrosive attack include economizer tube inlet headers, certain boiler tube areas, surface condenser tubes, and HP heaters. Problems occurring here may be related to EC or perhaps to the dissolution of copper or iron and its transport to some point elsewhere in the boiler system. If transported metal reaches certain critical areas (such as copper reaching turbine blades), very serious outages may occur. 

Make a preliminary mechanical design for the vertical thermosyphon reboiler for which the thermal design was done as Example 12.9 in Chapter 12. The inlet liquid nozzle and the steam connections will be 50 mm inside diameter. Flat plate end closures will be used on both headers. The reboiler will be hung from four bracket supports, positioned 0.5 m down from the top tube plate. The shell and tubes will be of semi-killed carbon steel. 

No No flow Valve V-19 closed HF Vaporizer inlet header plugged/frozen Loss of HF to B-l process consequences unknown. No known protection. 1 Action Item Determine die level of protection available and potential consequences in B-l Wing. 

The basic reason for using different control-valve trims is to keep the stability of the control loop fairly constant over a wide range of flows. Linear-trim valves are used, for example, when the pressure drop over the control valve is fairly constant and a linear relationship exists between the controlled variable and the flow rate of the manipulated variable. Consider the flow of steam from a constant-pressure supply header. The steam flows into the shell side of a heat exchanger. A process liquid stream flows through the tube side and is heated by the steam. There is a linear relationship between the process outlet temperature and steam flow (with constant process flow rate and inlet temperature) since every pound of steam provides a certain amount of heat. 

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