Performance of Louvered Devices as Air MixersU.S. National Bureau of Standards, 1970 - 20 pages As part of a study evaluating methods for reducing thermal gradients within the cross section of an air stream, three louvered mixing devices were investigated. Each of these devices was found to be capable of reducing the cross-sectional nonuniformity of air temperature to a few percent of the entering value. |
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Results 1-5 of 5
Page 1
... showed that thermal gradients within the cross section of an air stream can be effectively diminished through forced mixing . With the removal of the undesirable condition of temperature nonuniformity , the average temperature of the ...
... showed that thermal gradients within the cross section of an air stream can be effectively diminished through forced mixing . With the removal of the undesirable condition of temperature nonuniformity , the average temperature of the ...
Page 5
... showed that mixing caused by the inherent turbulence and duct configuration was less than 7 percent when calculated by the range method of de- termining effectiveness . When calculated by the standard deviation method , a higher value ...
... showed that mixing caused by the inherent turbulence and duct configuration was less than 7 percent when calculated by the range method of de- termining effectiveness . When calculated by the standard deviation method , a higher value ...
Page 14
... showed that the overall distance from the first mixing ele- ment to the point of maximum observed uni- formity was 4.75 duct diameters . Figure 22 shows how the effectiveness varied as the over- all distance was changed . EFFECTIVENESS ...
... showed that the overall distance from the first mixing ele- ment to the point of maximum observed uni- formity was 4.75 duct diameters . Figure 22 shows how the effectiveness varied as the over- all distance was changed . EFFECTIVENESS ...
Page 17
... showed very little ef- fect upon the air stream with respect to mix- ing . ( Velocity profiles taken before and after a number of layers of screen showed a distinct improvement in the uniformity of the velocity within the cross ...
... showed very little ef- fect upon the air stream with respect to mix- ing . ( Velocity profiles taken before and after a number of layers of screen showed a distinct improvement in the uniformity of the velocity within the cross ...
Page 18
... showed some sen- sitivity to temperature pattern . As shown in table 4 , the resistance to flow for the louvered strip and the concentric louver when described in multiples of velocity head was 7 and 5 , respectively , as compared to 38 ...
... showed some sen- sitivity to temperature pattern . As shown in table 4 , the resistance to flow for the louvered strip and the concentric louver when described in multiples of velocity head was 7 and 5 , respectively , as compared to 38 ...
Common terms and phrases
0.92 duct diameter 4.75 DUCT DIAMETERS air flow Air Mixers air passed AIR STREAM VELOCITY apparatus ASHRAE automatic data processing baffles blower Building Science Series Bureau of Standards cents circular band concentric louver mixing CONCENTRIC TEMPERATURE PATTERN cross section deg F Devices as Air DIAMETER DUCT FPM DIAMETERS MEAN VELOCITY direct the air DISTANCE BETWEEN MIXING downstream measuring station Duct Diam DUCT DIAMETERS MEAN duct wall elements in series evaluated FIGURE 17 flow rate held constant louver angle louver mixing device LOUVER SETTING louver-baffle mixing device louvered strip mixing MEAN AIR STREAM ment metal mixing effectiveness National Bureau normal path outer area path of flow PATTERN THREE QUADRANTS percent pitot-static tubes QUADRANT COOL QUADRANT TEMPERATURE PATTERN Resistance Thermometer shown in figure spacing between mixing standard deviation strip mixer strip mixing device tempera temperature difference TEMPERATURE PATTERN THREE test conditions THERMOCOUPLES THREE QUADRANTS WARM tion ture U.S. Government Printing velocity head
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Page 1 - A schematic of the apparatus is shown in figure 1. Figure 2 is a photograph of the apparatus.
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