Flanged slot

The analytical solution for an infinitely flanged slot can be obtained by assuming that the inlet is composed of elemental point sinks.The velocity field of an infinitely flanged slot can be obtained by assuming the velocity to be uniformly distributed across the opening. The contribution to the velocity potential at point (x, y) due to the elemental line sink of length and located at (0, Q is given by... 

FIGURE 10.14 Coordinate system used in the modeling of a flanged slot... 

FIGURE lO.iS Anafyti cal and line sink velocity contours for a flanged slot. 

Another design method uses capture efficiency. There are fewer models for capture efficiency available and none that have been validated over a wide range of conditions. Conroy and Ellenbecker - developed a semi-empirical capture efficiency for flanged slot hoods and point and area sources of contaminant. The point source model uses potential flow theory to describe the flow field in front of a flanged elliptical opening and an empirical factor to describe the turbulent diffusion of contaminant around streamlines. 

A flanged slot hood exhausts particulates produced in an operation. The flow volume for the exhaust system is 10,000 ft /min. The hood entry is 6 ft X 1 ft. 

Equations for centerline velocity outside circular, square, rectangular and slot exhausts without and with flanges are presented in Table 10.3. These equations have been chosen to have as large an application as possible. For very detailed calculations it is recommended that the original research references be consulted. 09,40... 

Rim exhausts are slot hoods located on or around the edge of a source such as an open surface tank. Flanges may be added to decrease the airflow from behind the slot (uncontaminated air) and therefore increase the airflow from in front of the slot (contaminated air). The plenum downstream of the slot, if located above the slot, may act as a flange. Flanges may also be added to the sides of the source (tank) away from the slot hood. These flanges also act to increase the flow of contaminated air into the tank. Tank flanges, however, may interfere with process activities by limiting access to the tank. 

The pressure loss associated with this type of exhaust opening is the sum of two pressure losses. The slot hood is usually thought of as a sharp-edged orifice and the duct entry (from the slot plenum) is a flanged opening. The rec ommended hood entry loss is given by Eq. (10.56) - ... 

A schematic diagram of the version of the Aaberg slot exhaust (ASE) system is shown in Fig. 10.81. It consists of a horizontal bench to which a vertical flange is attached, housing a rectangular exhaust slot and jet nozzle. Figure 10.82 shows the two-dimensional geometry and the coordinate system of the ASE model. 

The force and torque transfer is achieved via frictional contact of the taper connection at higher torques additional drive slots in the flange with different depth support the torque transfer. 

Cutters which are used close to the spindle, such as shell end mills, are mounted on a stub arbor. Fig. 11.10. This arbor is located, held, and driven in the spindle in the same way as a standard arbor. The cutter is located on a spigot or stub and is held in position by a large flanged screw. Two keys on the arbor provide the drive through key slots in the back face of the cutter. 

Sheet metal form features are placed on walls by positioning relationships such as holes, cutouts, slots, flanged punches, notches, depressions, channels, webs, corner and other stress reliefs, etc. They can be created in the flat pattern because it is associative to the folded state. Features and completed walls with all the form features can be copied or repositioned. In certain... 

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