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 6
Page 7
... varied as the distance between mixing elements varied . Under the conditions of the tests , the effective- ness increased gradually from 92.5 to 96.1 per- cent as the spacing was increased from 0.5 to 1.5 duct diameters ; it remained ...
... varied as the distance between mixing elements varied . Under the conditions of the tests , the effective- ness increased gradually from 92.5 to 96.1 per- cent as the spacing was increased from 0.5 to 1.5 duct diameters ; it remained ...
Page 8
... varied . Measurements were also made to compare the effectiveness of the mixer at two different louver angle positions . The results illustrated in figures 7 to 10 inclusive are for a position of 60 ° from the normal path of flow along ...
... varied . Measurements were also made to compare the effectiveness of the mixer at two different louver angle positions . The results illustrated in figures 7 to 10 inclusive are for a position of 60 ° from the normal path of flow along ...
Page 10
... varied . For temperature patterns of concentric and quadrant distributions , it was found that , for overall distances greater than 2.5 duct diameters from the first mixing ele- ment to the downstream measuring station , little ...
... varied . For temperature patterns of concentric and quadrant distributions , it was found that , for overall distances greater than 2.5 duct diameters from the first mixing ele- ment to the downstream measuring station , little ...
Page 11
... varied . 100 90 80 100 A QUADRANT TEMPERATURE PATTERN ( THREE QUADRANTS WARM AND ONE QUADRANT COOL ) ( OVERALL DISTANCE : 2.5 DUCT DIAMETERS , LOUVER SETTING : 60 ° ) 200 300 400 MEAN AIR STREAM VELOCITY IN THE TWO FOOT DIAMETER DUCT ...
... varied . 100 90 80 100 A QUADRANT TEMPERATURE PATTERN ( THREE QUADRANTS WARM AND ONE QUADRANT COOL ) ( OVERALL DISTANCE : 2.5 DUCT DIAMETERS , LOUVER SETTING : 60 ° ) 200 300 400 MEAN AIR STREAM VELOCITY IN THE TWO FOOT DIAMETER DUCT ...
Page 14
... varied . The results illustrated in figure 21 show that effec- tive mixing was gained when the elements were placed approximately two duct diameters apart , but that very little mixing would be lost by reducing the spacing down to one ...
... varied . The results illustrated in figure 21 show that effec- tive mixing was gained when the elements were placed approximately two duct diameters apart , but that very little mixing would be lost by reducing the spacing down to one ...
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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