Inlets, and Outlets

The location of the bin s inlet point (or points) is not as critical as the location and number of outlet points. However, inlet location may have some effect on particle segregation and/or bin loads. 

The next consideration is whether to use one or more outlets. In general, it is always preferable to use a single outlet that is centred on the vessel s centreline. This is particularly true if mass flow is to be achieved, particle segregation is a concern and/or there are bin loads considerations in designing the vessel. 

There are a number of considerations when sizing the bin outlet. If arching is a concern (either in mass flow or funnel flow), the discharge frequency must be considered since this sets the maximum time that the bulk solid will remain at rest within the vessel. If a funnel flow vessel is being designed, the critical rathole diameter will also be needed to set the minimum outlet dimensions. 

In addition to arching, ratholing and flow rate considerations, the size of the feeder must be considered. Most commercial feeders come in standard dimensions, so it may be necessary 

Sometimes with rate limiting powders an air permeation system or air-assisted discharge can be used to increase flow rate and thereby limit the outlet size. Some powders are also more suitable to being handled in a fluidised state, which also limits the outlet size. 

Considering the recycling strategy with a fixed pump, five fiow rates have to be controlled  

If because of the line switching the recycling pump is located in a different zone of the process, the flow rate has to be controlled accordingly. 

It has to be noticed that as two inlets and two outlets are applied to a closed loop, even if the sum of the inlet flow rates are equal to the sum of the outlet flow rates, a small difference will strongly increase or decrease the internal pressure of the process. Thus, the outlet flow rates have to be regulated based on the internal pressure of the liquid loop. 

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Many other mixed-feed arrangements are possible which combine the individual advantages of each type of arrangement. Figure 3.13 shows a three-stage evaporator in temperature-enthalpy terms, assuming that inlet and outlet solutions are at saturated conditions... 

Take note that Ft can therefore be regarded as depending only on the inlet and outlet temperatures of the streams in a 1-2 exchanger. Three basic situations can be encountered when using 1-2 exchangers (Fig. 7.8) ... 

A more sophisticated and increasingly popular method of on-condItion maintenance is to monitor the performance of equipment on-line. For example, a piece of rotating equipment such as a turbine may be monitored for vibration and mechanical performance (speed, inlet and outlet pressure, throughput). If a base-line performance is established, then deviations from this may indicate that the turbine has a mechanical problem which will reduce its performance or lead to failure. This would be used to alert the operators that some form of repair is required. 

Apparatus. 2-1 three-necked, round-bottomed flask, provided with a gas inlet tube, a gas-tight mechanical stirrer and a gas outlet two washing bottles filled with paraffin oil were connected with the gas inlet and outlet. 

ICIFM-21SP Monopolar Electrolyzers. Id s EM-21 SP monopolar electrolyzer incorporates stamped electrodes that are 2 mm thick and of a relatively small (0.2 m ) size (50). The electrolyte compartments are created by molded gaskets between two of the electrode plates the electrode spacing is finite and is estabHshed by gasket thickness. The electrode frames are supported from rails and are compressed between one fixed and one floating end plate by tie rods. Inlet and outlet streams are handled by internal manifolds. A crosscut view of the electrolyzer is shown in Eigure 21. As of 1989, ICI had Hcensed 20 plants having an annual capacity of 468,250 t of NaOH. 

The first bracketed term represents the pressure difference between the inlet and oudet no22les resulting from the difference in fluid velocity, acceleration or momentum, and the second bracketed term represents the pressure difference between the inlet and outlet no22les from the difference in elevation. 

Mercury vapor discharge from vents of reactors or storage tanks at normal atmospheric pressure is controlled readily by means of activated carbon. Standard units (208-L (55-gal) dmms) of activated carbon equipped with proper inlet and outlet nozzles can be attached to each vent. To minimize the load on the carbon-absorbing device, a small water-cooled condenser is placed between the vent and the absorber. 

The second step is to disperse the core material being encapsulated in the solution of shell material. The core material usually is a hydrophobic or water-knmiscible oil, although soHd powders have been encapsulated. A suitable emulsifier is used to aid formation of the dispersion or emulsion. In the case of oil core materials, the oil phase is typically reduced to a drop size of 1—3 p.m. Once a suitable dispersion or emulsion has been prepared, it is sprayed into a heated chamber. The small droplets produced have a high surface area and are rapidly converted by desolvation in the chamber to a fine powder. Residence time in the spray-drying chamber is 30 s or less. Inlet and outlet air temperatures are important process parameters as is relative humidity of the inlet air stream. 

The conditions for the carbon bum step are typically less than about 1.0 mol % oxygen, 400°C inlet temperature, 455°C maximum oudet temperature, which is controlled by adjusting the oxygen content of the circulating gas, and 0.45 to 2.2 MPa. The carbon bum is considered to be complete when no exotherm is observed for several hours. The oxygen concentration at all reactor inlets and outlets should be equal at this point. 

Reciprocating pumps are those most commonly used in high performance Ic. The single-piston type usually has inlet and outlet check valves with some mechanism such as variable stroke frequency to minimize the effect of pump pulsations. Dual-piston pumps operate with the pistons 180° out of phase to minimize pulsations. For this system to work optimally, the piston units must be identical. 

Process simulators stop generally at the process specifications for the equipment. For the detailed mechanical design of the equipment, such as heat exchangers and distillation columns, stand-alone programs are often used. They make process calculations, size the equipment, calculate thermal and mechanical stresses, design mechanical support of the parts of the equipment, design inlet and outlet nozzles, etc. 

The cod wound heat exchanger consists of multiple tubes heHcally wound on a mandrel, usually with spacers between each tube layer. The tubes are inserted into tube sheets at both ends of the tube bundle, with separate tube sheets to accommodate each tube circuit. The tube bundle is enclosed ia a sheU with inlet and outlet no22les for the sheUside fluid. This type of heat exchanger is usually constmcted of aluminum or stainless steel. Large aluminum... 

Whereas changing catalyst volume or residence time rarely yields compHcations, changing temperature or pressure could iatroduce sintering. The properties of the catalyst should be measured both before and after deactivation and inlet and outlet streams should be analyzed by chromatography (qv) or spectrometry. 

Here g is the gravity vector and tu is the force per unit area exerted by the surroundings on the fluid in the control volume. The integrand of the area integr on the left-hand side of Eq. (6-10) is nonzero only on the entrance and exit portions of the control volume boundary. For the special case of steady flow at a mass flow rate m through a control volume fixed in space with one inlet and one outlet, (Fig. 6-4) with the inlet and outlet velocity vectors perpendicular to planar inlet and outlet surfaces, giving average velocity vectors Vi and V9, the momentum equation becomes... 

Selecting the inlet and outlet surfaces 1 and 2 as shown, the continuity equation Eq. (6-9) can he used to find the exit velocity V2 = ViAi/A2. The mass flow rate is obtained by m = pViAi. 

Let us consider a cooler in the equipment flow sheet. The required rate of heat removal is known from the balances, and the rate of cooling water can be calculated once the inlet and outlet temperatures of the water have been specified. The calculation of the consumption of other utilities is also straightforward. Allowances should be made for wastage. 

The axial flow compressors in aero gas turbines are heavily loaded. The aspecl ratio of the blades, especially the first few stages, can be as high as 4.0, and the effecl of streamhne curvature is substantial. The streamline configuration is a function of the annular passage area, the camber and thickness distribution of the blade, and the flow angles at the inlet and outlet of the blades. The shafts on these units are supported on antifriction bearings (roller or ball bearings). 

Most coils are firmly clamped (but not welded) to supports. Supports should allow expansion but be rigid enough to prevent uncontrolled motion (see Fig. ll-29b). Nuts and bolts should be securely fastened. Reinforcement of the inlet and outlet connections through the tank wall is recommended, since bending stresses due to thermal expansion are usually high at such points. 

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