In fans

Typical tomographic 2D-reconstruction, like the filtered backprojection teelinique in Fan-Beam geometry, are based on the Radon transform and the Fourier slice theorem [6]. 

D. G. Traver, in Fan Application - Testing and Selection Symposium Papers, San Francisco, Calif, Jan. 1970, ASHRAE, Atlanta, 1972. 

Inverters make it possible to control a variable-speed fan by changing the frequency modulation. Standard alternating-current fan motors may be speed-regulated between 0 and 60 Hz. In using inverters for this apphcation, it is important to avoid frequencies that would result in fan critical speeds. 

Fluid couplings have a proven record of reliability and ease of operation. They thus have found wide application wherever a light load start and capticily control of drives is required as in fans and pumps. 

Example 6. Use the Increase in Fan Horsepower to Raise Circulation Rather Than Lower Cold Water Temp. 

Class Maximum leakage as % of total flow Increase in fan power... 

When a built-in fan and filter is used and the air is recirculated into the workroom, it is necessary to consider the influence of the contaminants on the overall concentration inside the work room. Moreover, it could be difficult to dampen the noise from a built-in fan with a large flow rate. Small tables do not have these problems, since they are connected with ducts to a central fan. 

The measured pressure differences in ventilation applications are low or very low. The measurement range varies from a few pascals to several thousand pascals. At the lower end are typically building leakage and air movement-related measurements, where only a few pascals can cause a remarkably large air-tlow. The largest pressure differences probably occur in fan performance determination and similar applications. This wide range requires special demands on the measuring equipment and selection of the correct instrument for each application (Fig. 12.15). 

Figure34.16 The effects of corrosion. Structural failure is visible (holes in fan casing)...

Ductless hoods are equipped with built-in fans and filter systems which trap the volatiles being removed. In this manner, the spent air can be returned to the laboratory, thereby eliminating the need for exhaust ducts. The filter system must be tailored to the types of fumes to be removed. Its use is therefore limited and... 

The cone calorimeter used in this study (5) is a somewhat enlarged version of the model used at the National Institute of Standards and Technology in the United States. This particular equipment takes samples of size 20 cm x 20 cm mounted in a horisontal position on top of a load cell. Above the sample there is a cone heater and a spark ignitor. Gas samples are taken in fan ventilated exhaust duct mounted above the cone heater. The radiation used has been 50 kW/m2 and free convection ventilation over the sample. 

Air mass flow sensors can be used in fans and vacuum cleaners. 

SQP. This is a sister code to GRG2 and available from the same source. The interfaces to SQP are very similar to those of GRG2. SQP is useful for small problems as well as large sparse ones, employing sparse matrix structures throughout. The implementation and performance of SQP are documented in Fan, et al. (1988). 

As mentioned in the previous section, a major drawback of the simplex atomizer is the poor atomization quality at the lowest flow rate due to too-low pressure differential if swirl ports are sized to allow the maximum flow rate at the maximum injection pressure. This problem may be resolved by using dual-orifice, duplex, or spill-return atomizers. Alternatively, the atomization processes at low injection pressures can be augmented via forced aerodynamic instabilities by using air or gas stream(s) or jet(s). This is based on the beneficial effect of flowing air in assisting the disintegration of a liquid j et or sheet, as recognized in the application of the shroud air in fan spray and pressure-swirl atomization. 

In fan spray atomization, the effects of process parameters on the mean droplet size are similar to those in pressure-swirl atomization. In general, the mean droplet size increases with an increase in liquid viscosity, surface tension, and/or liquid sheet thickness and length. It decreases with increasing liquid velocity, liquid density, gas density, spray angle, and/or relative velocity between liquid and surrounding air. 

As with rockets, Roman candles may be fired individually or in fans or bouquets to give a multiple effect (Figure 8.1 and 8.2). 

The paper discusses operating limitations imposed by the turbine exhaust element and the alternatives presently available to the electric utility industry. It also presents tools for estimating dry tower plot area, fan power and circulating pump power requirements. It shows the savings in fan power which can be expected with a decrease in turbine-generator load and ambient air temperatures. It discusses expected maintenance costs and the owner s possible exposure with a large 1000 MW dry cooling tower system. The paper ends with an evaluation of the potential for lower dry tower system costs in the future. 12 refs, cited. 

When the conditions are such that a lowering of the approach (or Tctws) would require a large increase in fan operating costs (Ml"), the minimum point on the total cost curve (A"). will be above the minimum attainable approach (A ). Conversely, if the approach can be reduced with a small increase in fan operating costs (MT) the optimum operating point for the total system will correspond to the minimum Tctws temperature and therefore would be at the minimum attainable approach (A t). Whichever total... 

P C Johns and M J Yaffe (1982) Scattered radiation in fan-beam imaging systems. Med. 

MagniView 4800 is cooled by an ultraquiet built-in fan and an infrared heat filter. This allows operation of the pand on a transmissive overhead projector, without overheating or affecting the quality of the projected image. 

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