CA1137350A - Air circulator - Google Patents
Air circulatorInfo
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- CA1137350A CA1137350A CA000310307A CA310307A CA1137350A CA 1137350 A CA1137350 A CA 1137350A CA 000310307 A CA000310307 A CA 000310307A CA 310307 A CA310307 A CA 310307A CA 1137350 A CA1137350 A CA 1137350A
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- air
- duct
- circulator
- column
- space
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Abstract
An air circulator apparatus and method for movement of large amounts of air in a confined space, e.g. a room or industrial building, are disclosed. Movement of air overcomes stratification of warmer air near the ceiling of the confined space. The apparatus has a duct through which cool primary air is moved from the floor level to the upper warmer air mass near the top of the room in an air column which induces secondary air into the column so that the air density at the top of the column is substantially less than that at the bottom of the column. The duct contains air advancing means in the form of a motor driven fan having propeller blades and a baffle to advance the air from the lower level and may also include air channelling means disposed between the air advancing means and the outlet opening of the duct. The air is moved through the apparatus at a velocity of at least 800 feet per minute.
Description
This invention is concerned with heating and ventilating equipment and, more particularly, with an air circulator apparatus for and a method of movement of large quantities of air within a confined space, e.g. a room.
Heating of large volumes of air in domestic and industrial buildings presents numerous problems.
One problem resides in stratification of the air whereby relatively warm air rises to lie on top of the relatively cooler air in the confined space of a room or building. Such stratification of air is undesirable, because, for one reason the heat loss from the building through the roof is increased on account of the warmer air lying adjacent the ceiling or roof.
Also, in order to keep the lower, cooler air mass at a desired temperature, it will normally be necessary to maintain the upper, warmer air mass at an excessive temperature.
This adds further to an inefficient energy usage.
The warmer air near the ceiling or roof of the confined space, represents a considerable waste in energy because the stored heat therein does not efficiently contribute to the heating comfort of personnel exposed to the air near floor level in the confined space.
It is common to mount fans at the ceiling or roof portion of buildings to attempt to blow the warmer air in a downward direction, thereby to overcome stratification. Such movement of warm air in a downward direction is not wholly effective since the warmer air will separate and eventually rise again to the upper stratum. When ceiling fans are operated at a high air movement velocity, air currents may be produced of a sufficient magnitude to cause homogenization of the air.
-~ li37350 Such a system may require excessive amounts of energy to drive the fans and produce uncomfortable working conditions for personnel immediately below and in the vicinity under the fans because of the strong downward air currents caused by the fans.
The present invention provides an air circulator apparatus and method which moves air in a confined space, such as a room, from the lower, cooler air stratum through an air flow duct to the higher, warmer air stratum in the confined space. Such upward movement of the cooler air causes the downward movement of warmer air in replacement thereof, thus introducing warmer air to the lower levels, where it is most needed. Air is preferably passed upwardly through the air flow duct at a velocity of at least about 800 feet per minute.
The air is advantageously moved at a volume rate of from about 1000 to 4000 cubic feet per minute.
Thus, according to the present invention there is provided an air circulator for disposition in a confined space, comprising an upright air flow directing duct; air inlet means at a lower portion of the duct; upwardly facing air outlet means at the top of the duct; a blower for moving primary air from the inlet means to the outlet means of the duct; the blower and the duct together constituting means effective, when the circulator is disposed in the space, to establish a fast moving, unconstrained column of air extending from the outlet means towards the top of the space and effective to induce substantial quantities of secondary air into the column; the blower having a capacity such that the density of air at the top of the column is substantially reduced over the density of air at the bottom of the column.
Also in accordance with the present invention there is provided a method of conserving heating energy in the heating of a confined space which comprises disposing an air circulator on a floor of the space, the air circulator having an air flcw directing duct with an air inlet means at a lower portion of the the duct and an upwardly facing air outlet means at the top of the duct and a blower moving primary air from the inlet means to the outlet means; the air outlet being spaced a substantial distance from the top of the space; and operating the blower in such a way that a fast moving column of primary air extending from the outlet means towards the top of the space is established; the column issuing from the air outlet means at a speed to cause substantial quantities of secondary air to be induced into the column from a region of the space between the air outlet means and the top of the room so that a resultant mixture of primary air and secondary air reaching the upper regions of this space has a density substantially less than the density of air at the bottom of the column, thus substantially limiting the extent to which the air delivered to the top of the space by the circulator can fall towards the floor.
The apparatus and method of the present invention thus work contrary to the above-mentioned prior art arrangements in that they circulate cold air upwardly instead of attempting to force warm air downwardly within the confines of the room. As a result, there are provided comfortable, substantially draft-free heated conditions in the lower levels of the room where personnel are located, utilizing the heated air wastefully accumulated in the higher levels of the confined space. The apparatus includes no heating means of its own. It is thus _ ~_ _ 1137350 extremely economical in its energy requirements in its energy requirements and worXs simply, quietly and effectively with a minimum of maintenance.
Preferably, the duct comprises a square-section, longitudinal air flow duct defining an upwardly extending air advancing passage.
The duct may be formed from sheet metal, and suitably has an upwardly presented outlet opening and a downwardly presented inlet opening.
The duct can be supported at its lowermost end on support legs forming between them outwardly presented inlet openings for noise-free intake of air. The total area of the outwardly presented inlet openings should correspond in size approximately to that of the upwardly presented outlet opening of the duct.
- 3a -The blower suitably comprises a fan powered by a motor. The fan can be a three propeller blade fan having propeller blades disposed at a pitch angle of from about 24 to 32, The motor can be supported on a suitable support bracket and, preferably, can be located in the lower third of the height of the duct.
In order to move the air in the form of a relatively continuous stream through the duct, suitably a baffle plate can be provided adjacent the propeller blades, which baffle preferably has a central circular opening slightly larger in size than the rotating blade diameter of the fan that is employed.
A filter can be employed, located near the inlet means of the duct, to remove undesirable impurities from the stream of air flowing through the duct.
At or near the upwardly presented outlet means of the duct there can be provided a grating for preventing foreign material from entering downwardly into the duct and damaging the fan and motor of the unit.
Advantageously, the apparatus can be of square cross-section and may be of a height of at least 3 times the length of one side of the duct.
In the upper part of the duct there can be provided air channelling means such as a bundle of tubes or a single duct to reduce spinning of air that is passed through the apparatus.
In order to achieve a decrease in the temperature difference of the upper and lower air strata, the velocity of air being expelled through the upwardly presented outlet opening is preferably at least 800 feet per minute. The upper limit of this velocity is preferably near 2200 feet per minute.
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The present invention is particularly useful for large volume industrial buildings, i.e. buildings having a volume o~ at least 80 - 90,000 cubic feet. For such a building one unit will be adequate to provide the desired homogenization of air, or in other words, to prevent stratification, while for a larger building further circulator units will be required.
Advantageously, the height of the duct is approximaiely 5 feet which is sufficient to shield a person from drafts alongside the duct.
There should be adequate room between the ~r~ outlet C DrA~lng of the duct and the ceiling in order to allow for ade~uate air distribution at the ceiling.
On the other hand, the apparatus of the present invention can be modified for use in smaller rooms by restricting the cross-sectional area; however, the height of the duct is to be selected so that approximately 2 - 3 feet are kept clear between the ceiling of the room and the outlet opening of the duct. This will provide sufficient space for air circulation and will serve to heat a small room as effectively as a large industrial size confined space.
Specific preferred embodiment of the invention are shown in the accompanying drawings, in which:
FIGURE 1 is a perspective view of the air circulator according to one embodiment in accordance with the present invention with part of the duct walls shown broken away to reveal the interiorally arranged parts of the apparatus;
FIGURE 2 is a perspective view of the air circulator apparatus in accordance with Figure 1, located in a confined space and indicating diagrammatically the redistribution of air from a lower sf ratum to an upper stratum;
.:
FIGURE 3 is a perspective view of a further embodiment of an air circulator in accordance with the present invention with air channelling means arranged in the upper part of the circulator duct; and FIGURE 4 is a perspective view of yet another embodiment also with an air channelling means in the upper part of the duct.
Figure 2 shows the air circulator 10 for movement of air from a lower stratum 12 to a higher, upper stratum 14.
While no clear transition boundary exists between the lower and :10 upper strata, the air mass at floor level 16 is normally appreciably cooler than the temperature of the air mass adjacent the ceiling. The circulator 10 in the embodiment described herein is capable of moving air from lower stratum 12, at floor level 16, to the upper stratum 14 in a room about 20 feet high and having a volume of about 90,000 cubic feet.
As can best be seen with reference to Figure 1, air circulator 10 comprises a generally square cross-section, upright air flow duct formed by a pair of rectangular, opposed panels, namely, fron~ panel 20 and rear panel 22, each comprising a pair of integrally formed, lower support legs 24 and a continuous support strip 26. To complete the duct, two rectangular side panels, 28 and 30, are secured to the panels 20 and 22 by attach-ment means 32 such as rivets, metal screws or the like. The panels thus form a continuous envelope defining an air advancing passage for movement of air from the lower, downwardly directed, horizontal inlet opening 34 to the upwardly directed, horizontal outlet opening 3~ of the air flow duct.
The support legs 24 of the duct define outwardly presented inlet openings 38 for air to be passed through the circulator 10 from the lower stratum 12 to upper stratum 14.
The sum of the areas of the four openings 38 is approximately equal to or is slightly greater than the upwardly presented outlet opening 36 of the air flow duct of the circulator 10.
The inlet opening 34 is covered by a filter 40, such a a compacted-fibre comprising filter, or a similar furnace _. 7 _ u filter. The filter 40 removes impurities from the air passed through the air flow duct and, thus, adds to the hygiene of a room in which the air circulator 10 is used. A support bracket 42 is secured, not shown, to panel 30 in the lower part of the duct of circulator 10, but above the filter 40, for mounting thereon of electric motor 44, having secured to its output shaft a fan comprising three propeller blades 46. Each blade 46 is disposed at a pitch angle of about 28 with respect to the horizontal plane.
Arranged approximately at the same height as the propeller blades 46 is a baffle plate 48, having a central circular opening 50, the baffle plate 48 being secured to the side panels 28, 30 and front and back panels 20, 22 respectively.
Baffle plate 48 is positioned near the central height of the blades 46 within the duct so that the blades 46 will move the maximum amount of air through the opening 50 in baffle plate 48.
When the propeller blades 46 are positioned higher or lower than opening 50, less air is moved through the duct.
The upwardly presented outlet opening 36 of the air circulator 10 is covered by an expanded metal qrating 52 to ` prevent foreign material entering into the circulator 10. The ; grating otherwise will not restrict the outflow of air Motor 44 is a 120 volt, 60 cycle motor capable of expelling air from the duct at a velocity of from about 800 to 2200 feet per minute. At a velocity of less than 800 feet per minute, the throughput of air is decreased and the effectiveness of the unit is correspondingly reduced. Conversely, velocities in excess of 2200 feet per minute have overall energy requirements out of proportion to the degree of temperature adjustment which r~ 30 can be achieved by the unit.
At the lower velocity and with filter 40 in place, a motor producing about 1140 r.p.m. can displace approximately 1000 cubic feet of air per minute. When filter 40 is removed, the throughput can be increased to approximately 1850 cubic feet per minute.
The output rate of the motor can be increased progressively by using an appropriate motor, or using separate motors, to achieve a motor rating of about 1800 r.p.m.. At this higher motor output, the volume of air expelled through the i upwardly presented outlet opening 36 is approximately 1500 cubic feet per minute when filter 40 is in use. Without a filter, the volume can be increased to 3500 cubic feet of air per minute.
The operation of the unit is simple. Motor 44 is started by a suitable switch, not shown, and the propeller blades 46 are rotated. Primary air is withdrawn from the floor level 16, i.e. from the lower stratum 12, through the outwardly presented openings 38 formed by the legs 24 and thence through ~ilter 40. The primary air then passes through the baffle opening 50 of the baffle 48, and is expelled at the upwardly presented outlet opening 36 of the duct. The grating 48 does not restrict this outflow of air.
Under the preferred conditions, the air is expelled at a velocity of at least 800 feet per minute, up to a maximum velocity of about 2200 feet per minute.
Under the outlined conditions, the air is expelled in a continuous stream formation, in a straight line direction ., towards the ceiling of the room. This stream formation forms a fast upwardly moving column of primary air. The outlet opening 36 is spaced a substantial distance from the ceiling and the column of air issues from the outlet opening 36 at a speed to ' ,:: 9 -`~ il37350 cause substantial quantities of secondary air to be induced into the column from a region of the room between the outlet opening 36 and the ceiling so that a resultant mixture of primary and secondary air reaching the upper regions of the room has a density substantially less than the density of air at the bottom of the column, thus substantially limiting the extent to which the air delivered to the ceiling by the circulator can fall towards the floor. Near the ceiling of the room, the air is dispersed laterally and flows towards the centre of the room from where it gradually sinks downward as it replaces fresh air drawn into the outwardly presented inlet openings 38 of the air flow duct.
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- 9a -.~
Another embodiment of an air circulator in accordance with the present invention is shown in Figure 3.
In this embodiment, air circulator 60 is formed of front and rear panels 62, 64 and side panels 66, 68, to provide a generally square cross-section air flow duct with an inlet opening 70 and an outlet opening 72. Downwardly presented inlet opening 70 is closed by a filter 74, and the outlet opening 72 is covered by an expanded metal grating 76. A bracket 78 is secured to panel 66, not shown in detail, for support thereby of motor 80 in the lower part of air circulator 60. Motor 80 serves to rotate a fan with three propeller blades 82. A baffle plate 84, having a circular opening 86, is secured to the panels 62, 64 and 66, ,68, not shown in detail.
Baffle 84 is positioned near the central height of blades 82 so that the maximum amount of air is moved through the duct.
", ; Air channelling means are provided between the baffle 84 and the grating 76, comprised of vertically disposed tubes :. .
88, held together by two straps 90, 92. Straps 90 and 92 are , 20 secured to the panels 62, 64 and 66, 68, not shown in detail.
The upper ends of the tubes 88 are flush with respect , to each other and terminate at a distance slightly below grating 76. The lower ends of tubes 88 are also flush with respect to each other and extend downwardly but so as to be clear of the rotating propeller blades 82.
, ~, .
Each of the tubes 88 has an inner diameter of approximately four inches. The number of tubes employed in the bundle will be aictated by the opening in the baffle 84 and normally will be such that the adjoining tubes cover or slightly exceed in area the opening 86 of baffle 84.
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The air circulator 60 has openings 92 for suspendingly disposing the apparatus in a confined room by means of wires, chains or the like, not shown in detail.
Yet another embodiment of an air circulator in accord-ance with the present invention is shown in Figure 4.
This embodiment corresponds largely to the embodiment shown in Figure 1 and will thus only briefly be described with respect to the modifications. The air duct 100 of this embodi-ment has a baffle 102 arranged near the central height of propeller blades 104. A expanded metal grating 106 is associated with the corresponding outlet opening 108 of this air circulator.
A cylindrical duct 110 is disposed between baffle 102 and outlet grating 106. As indicated in Figure 4, the cylindrical duct can be supported on the baffle 102 and, therefore, may be provided with leg portions for fastening to the bdffle, not shown, or can ;; be similarly fastened as will be obvious to those skilled in the art. Alternatively, the cylindrical duct 110 may be suspended to be clear of the propeller blades 104 by suitable suspension means, not shown, within the upper part of duct 100.
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Air circulators in accordance with the embodiment shown in Figures 3 and 4 will be effective in providing improved ; penetration of cooler air which is moved from lower strata into the upper strata. The embodiments are particularly useful in removing cooler air to relatively higher strata in high buildings such as, for example, warehouses, industrial plants and the liXe high confined spaces and decrease undesirable spinning of the air being passed through the respective ducts.
It will be appreciated that modifications can be made to the specific embodiments described above.
The support of an air circulator duct may be provided by a single, central support leg and which is attached to the sidewall-forming panels of the duct by suitable braces. The outwardly presented openings will then be disposed at an incline with respect to the floor level.
The cross-sectional shape of a duct, when viewed in plan, is preferably square as described, but may be round or of other suitable cross-sectional shape as desired.
It will be appreciated that the above specific embodi-ments are described in detail for illustrative purposes only, and are not to be construed as limiting the invention. The scope of the present invention is limited solely by the appended claims.
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Heating of large volumes of air in domestic and industrial buildings presents numerous problems.
One problem resides in stratification of the air whereby relatively warm air rises to lie on top of the relatively cooler air in the confined space of a room or building. Such stratification of air is undesirable, because, for one reason the heat loss from the building through the roof is increased on account of the warmer air lying adjacent the ceiling or roof.
Also, in order to keep the lower, cooler air mass at a desired temperature, it will normally be necessary to maintain the upper, warmer air mass at an excessive temperature.
This adds further to an inefficient energy usage.
The warmer air near the ceiling or roof of the confined space, represents a considerable waste in energy because the stored heat therein does not efficiently contribute to the heating comfort of personnel exposed to the air near floor level in the confined space.
It is common to mount fans at the ceiling or roof portion of buildings to attempt to blow the warmer air in a downward direction, thereby to overcome stratification. Such movement of warm air in a downward direction is not wholly effective since the warmer air will separate and eventually rise again to the upper stratum. When ceiling fans are operated at a high air movement velocity, air currents may be produced of a sufficient magnitude to cause homogenization of the air.
-~ li37350 Such a system may require excessive amounts of energy to drive the fans and produce uncomfortable working conditions for personnel immediately below and in the vicinity under the fans because of the strong downward air currents caused by the fans.
The present invention provides an air circulator apparatus and method which moves air in a confined space, such as a room, from the lower, cooler air stratum through an air flow duct to the higher, warmer air stratum in the confined space. Such upward movement of the cooler air causes the downward movement of warmer air in replacement thereof, thus introducing warmer air to the lower levels, where it is most needed. Air is preferably passed upwardly through the air flow duct at a velocity of at least about 800 feet per minute.
The air is advantageously moved at a volume rate of from about 1000 to 4000 cubic feet per minute.
Thus, according to the present invention there is provided an air circulator for disposition in a confined space, comprising an upright air flow directing duct; air inlet means at a lower portion of the duct; upwardly facing air outlet means at the top of the duct; a blower for moving primary air from the inlet means to the outlet means of the duct; the blower and the duct together constituting means effective, when the circulator is disposed in the space, to establish a fast moving, unconstrained column of air extending from the outlet means towards the top of the space and effective to induce substantial quantities of secondary air into the column; the blower having a capacity such that the density of air at the top of the column is substantially reduced over the density of air at the bottom of the column.
Also in accordance with the present invention there is provided a method of conserving heating energy in the heating of a confined space which comprises disposing an air circulator on a floor of the space, the air circulator having an air flcw directing duct with an air inlet means at a lower portion of the the duct and an upwardly facing air outlet means at the top of the duct and a blower moving primary air from the inlet means to the outlet means; the air outlet being spaced a substantial distance from the top of the space; and operating the blower in such a way that a fast moving column of primary air extending from the outlet means towards the top of the space is established; the column issuing from the air outlet means at a speed to cause substantial quantities of secondary air to be induced into the column from a region of the space between the air outlet means and the top of the room so that a resultant mixture of primary air and secondary air reaching the upper regions of this space has a density substantially less than the density of air at the bottom of the column, thus substantially limiting the extent to which the air delivered to the top of the space by the circulator can fall towards the floor.
The apparatus and method of the present invention thus work contrary to the above-mentioned prior art arrangements in that they circulate cold air upwardly instead of attempting to force warm air downwardly within the confines of the room. As a result, there are provided comfortable, substantially draft-free heated conditions in the lower levels of the room where personnel are located, utilizing the heated air wastefully accumulated in the higher levels of the confined space. The apparatus includes no heating means of its own. It is thus _ ~_ _ 1137350 extremely economical in its energy requirements in its energy requirements and worXs simply, quietly and effectively with a minimum of maintenance.
Preferably, the duct comprises a square-section, longitudinal air flow duct defining an upwardly extending air advancing passage.
The duct may be formed from sheet metal, and suitably has an upwardly presented outlet opening and a downwardly presented inlet opening.
The duct can be supported at its lowermost end on support legs forming between them outwardly presented inlet openings for noise-free intake of air. The total area of the outwardly presented inlet openings should correspond in size approximately to that of the upwardly presented outlet opening of the duct.
- 3a -The blower suitably comprises a fan powered by a motor. The fan can be a three propeller blade fan having propeller blades disposed at a pitch angle of from about 24 to 32, The motor can be supported on a suitable support bracket and, preferably, can be located in the lower third of the height of the duct.
In order to move the air in the form of a relatively continuous stream through the duct, suitably a baffle plate can be provided adjacent the propeller blades, which baffle preferably has a central circular opening slightly larger in size than the rotating blade diameter of the fan that is employed.
A filter can be employed, located near the inlet means of the duct, to remove undesirable impurities from the stream of air flowing through the duct.
At or near the upwardly presented outlet means of the duct there can be provided a grating for preventing foreign material from entering downwardly into the duct and damaging the fan and motor of the unit.
Advantageously, the apparatus can be of square cross-section and may be of a height of at least 3 times the length of one side of the duct.
In the upper part of the duct there can be provided air channelling means such as a bundle of tubes or a single duct to reduce spinning of air that is passed through the apparatus.
In order to achieve a decrease in the temperature difference of the upper and lower air strata, the velocity of air being expelled through the upwardly presented outlet opening is preferably at least 800 feet per minute. The upper limit of this velocity is preferably near 2200 feet per minute.
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The present invention is particularly useful for large volume industrial buildings, i.e. buildings having a volume o~ at least 80 - 90,000 cubic feet. For such a building one unit will be adequate to provide the desired homogenization of air, or in other words, to prevent stratification, while for a larger building further circulator units will be required.
Advantageously, the height of the duct is approximaiely 5 feet which is sufficient to shield a person from drafts alongside the duct.
There should be adequate room between the ~r~ outlet C DrA~lng of the duct and the ceiling in order to allow for ade~uate air distribution at the ceiling.
On the other hand, the apparatus of the present invention can be modified for use in smaller rooms by restricting the cross-sectional area; however, the height of the duct is to be selected so that approximately 2 - 3 feet are kept clear between the ceiling of the room and the outlet opening of the duct. This will provide sufficient space for air circulation and will serve to heat a small room as effectively as a large industrial size confined space.
Specific preferred embodiment of the invention are shown in the accompanying drawings, in which:
FIGURE 1 is a perspective view of the air circulator according to one embodiment in accordance with the present invention with part of the duct walls shown broken away to reveal the interiorally arranged parts of the apparatus;
FIGURE 2 is a perspective view of the air circulator apparatus in accordance with Figure 1, located in a confined space and indicating diagrammatically the redistribution of air from a lower sf ratum to an upper stratum;
.:
FIGURE 3 is a perspective view of a further embodiment of an air circulator in accordance with the present invention with air channelling means arranged in the upper part of the circulator duct; and FIGURE 4 is a perspective view of yet another embodiment also with an air channelling means in the upper part of the duct.
Figure 2 shows the air circulator 10 for movement of air from a lower stratum 12 to a higher, upper stratum 14.
While no clear transition boundary exists between the lower and :10 upper strata, the air mass at floor level 16 is normally appreciably cooler than the temperature of the air mass adjacent the ceiling. The circulator 10 in the embodiment described herein is capable of moving air from lower stratum 12, at floor level 16, to the upper stratum 14 in a room about 20 feet high and having a volume of about 90,000 cubic feet.
As can best be seen with reference to Figure 1, air circulator 10 comprises a generally square cross-section, upright air flow duct formed by a pair of rectangular, opposed panels, namely, fron~ panel 20 and rear panel 22, each comprising a pair of integrally formed, lower support legs 24 and a continuous support strip 26. To complete the duct, two rectangular side panels, 28 and 30, are secured to the panels 20 and 22 by attach-ment means 32 such as rivets, metal screws or the like. The panels thus form a continuous envelope defining an air advancing passage for movement of air from the lower, downwardly directed, horizontal inlet opening 34 to the upwardly directed, horizontal outlet opening 3~ of the air flow duct.
The support legs 24 of the duct define outwardly presented inlet openings 38 for air to be passed through the circulator 10 from the lower stratum 12 to upper stratum 14.
The sum of the areas of the four openings 38 is approximately equal to or is slightly greater than the upwardly presented outlet opening 36 of the air flow duct of the circulator 10.
The inlet opening 34 is covered by a filter 40, such a a compacted-fibre comprising filter, or a similar furnace _. 7 _ u filter. The filter 40 removes impurities from the air passed through the air flow duct and, thus, adds to the hygiene of a room in which the air circulator 10 is used. A support bracket 42 is secured, not shown, to panel 30 in the lower part of the duct of circulator 10, but above the filter 40, for mounting thereon of electric motor 44, having secured to its output shaft a fan comprising three propeller blades 46. Each blade 46 is disposed at a pitch angle of about 28 with respect to the horizontal plane.
Arranged approximately at the same height as the propeller blades 46 is a baffle plate 48, having a central circular opening 50, the baffle plate 48 being secured to the side panels 28, 30 and front and back panels 20, 22 respectively.
Baffle plate 48 is positioned near the central height of the blades 46 within the duct so that the blades 46 will move the maximum amount of air through the opening 50 in baffle plate 48.
When the propeller blades 46 are positioned higher or lower than opening 50, less air is moved through the duct.
The upwardly presented outlet opening 36 of the air circulator 10 is covered by an expanded metal qrating 52 to ` prevent foreign material entering into the circulator 10. The ; grating otherwise will not restrict the outflow of air Motor 44 is a 120 volt, 60 cycle motor capable of expelling air from the duct at a velocity of from about 800 to 2200 feet per minute. At a velocity of less than 800 feet per minute, the throughput of air is decreased and the effectiveness of the unit is correspondingly reduced. Conversely, velocities in excess of 2200 feet per minute have overall energy requirements out of proportion to the degree of temperature adjustment which r~ 30 can be achieved by the unit.
At the lower velocity and with filter 40 in place, a motor producing about 1140 r.p.m. can displace approximately 1000 cubic feet of air per minute. When filter 40 is removed, the throughput can be increased to approximately 1850 cubic feet per minute.
The output rate of the motor can be increased progressively by using an appropriate motor, or using separate motors, to achieve a motor rating of about 1800 r.p.m.. At this higher motor output, the volume of air expelled through the i upwardly presented outlet opening 36 is approximately 1500 cubic feet per minute when filter 40 is in use. Without a filter, the volume can be increased to 3500 cubic feet of air per minute.
The operation of the unit is simple. Motor 44 is started by a suitable switch, not shown, and the propeller blades 46 are rotated. Primary air is withdrawn from the floor level 16, i.e. from the lower stratum 12, through the outwardly presented openings 38 formed by the legs 24 and thence through ~ilter 40. The primary air then passes through the baffle opening 50 of the baffle 48, and is expelled at the upwardly presented outlet opening 36 of the duct. The grating 48 does not restrict this outflow of air.
Under the preferred conditions, the air is expelled at a velocity of at least 800 feet per minute, up to a maximum velocity of about 2200 feet per minute.
Under the outlined conditions, the air is expelled in a continuous stream formation, in a straight line direction ., towards the ceiling of the room. This stream formation forms a fast upwardly moving column of primary air. The outlet opening 36 is spaced a substantial distance from the ceiling and the column of air issues from the outlet opening 36 at a speed to ' ,:: 9 -`~ il37350 cause substantial quantities of secondary air to be induced into the column from a region of the room between the outlet opening 36 and the ceiling so that a resultant mixture of primary and secondary air reaching the upper regions of the room has a density substantially less than the density of air at the bottom of the column, thus substantially limiting the extent to which the air delivered to the ceiling by the circulator can fall towards the floor. Near the ceiling of the room, the air is dispersed laterally and flows towards the centre of the room from where it gradually sinks downward as it replaces fresh air drawn into the outwardly presented inlet openings 38 of the air flow duct.
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- 9a -.~
Another embodiment of an air circulator in accordance with the present invention is shown in Figure 3.
In this embodiment, air circulator 60 is formed of front and rear panels 62, 64 and side panels 66, 68, to provide a generally square cross-section air flow duct with an inlet opening 70 and an outlet opening 72. Downwardly presented inlet opening 70 is closed by a filter 74, and the outlet opening 72 is covered by an expanded metal grating 76. A bracket 78 is secured to panel 66, not shown in detail, for support thereby of motor 80 in the lower part of air circulator 60. Motor 80 serves to rotate a fan with three propeller blades 82. A baffle plate 84, having a circular opening 86, is secured to the panels 62, 64 and 66, ,68, not shown in detail.
Baffle 84 is positioned near the central height of blades 82 so that the maximum amount of air is moved through the duct.
", ; Air channelling means are provided between the baffle 84 and the grating 76, comprised of vertically disposed tubes :. .
88, held together by two straps 90, 92. Straps 90 and 92 are , 20 secured to the panels 62, 64 and 66, 68, not shown in detail.
The upper ends of the tubes 88 are flush with respect , to each other and terminate at a distance slightly below grating 76. The lower ends of tubes 88 are also flush with respect to each other and extend downwardly but so as to be clear of the rotating propeller blades 82.
, ~, .
Each of the tubes 88 has an inner diameter of approximately four inches. The number of tubes employed in the bundle will be aictated by the opening in the baffle 84 and normally will be such that the adjoining tubes cover or slightly exceed in area the opening 86 of baffle 84.
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The air circulator 60 has openings 92 for suspendingly disposing the apparatus in a confined room by means of wires, chains or the like, not shown in detail.
Yet another embodiment of an air circulator in accord-ance with the present invention is shown in Figure 4.
This embodiment corresponds largely to the embodiment shown in Figure 1 and will thus only briefly be described with respect to the modifications. The air duct 100 of this embodi-ment has a baffle 102 arranged near the central height of propeller blades 104. A expanded metal grating 106 is associated with the corresponding outlet opening 108 of this air circulator.
A cylindrical duct 110 is disposed between baffle 102 and outlet grating 106. As indicated in Figure 4, the cylindrical duct can be supported on the baffle 102 and, therefore, may be provided with leg portions for fastening to the bdffle, not shown, or can ;; be similarly fastened as will be obvious to those skilled in the art. Alternatively, the cylindrical duct 110 may be suspended to be clear of the propeller blades 104 by suitable suspension means, not shown, within the upper part of duct 100.
, .
Air circulators in accordance with the embodiment shown in Figures 3 and 4 will be effective in providing improved ; penetration of cooler air which is moved from lower strata into the upper strata. The embodiments are particularly useful in removing cooler air to relatively higher strata in high buildings such as, for example, warehouses, industrial plants and the liXe high confined spaces and decrease undesirable spinning of the air being passed through the respective ducts.
It will be appreciated that modifications can be made to the specific embodiments described above.
The support of an air circulator duct may be provided by a single, central support leg and which is attached to the sidewall-forming panels of the duct by suitable braces. The outwardly presented openings will then be disposed at an incline with respect to the floor level.
The cross-sectional shape of a duct, when viewed in plan, is preferably square as described, but may be round or of other suitable cross-sectional shape as desired.
It will be appreciated that the above specific embodi-ments are described in detail for illustrative purposes only, and are not to be construed as limiting the invention. The scope of the present invention is limited solely by the appended claims.
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Claims (11)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS
1. An air circulator for disposition in a confined space, comprising:
an upright air flow directing duct;
air inlet means at a lower portion of said duct;
upwardly facing air outlet means at the top of said duct; and a blower for moving primary air from the inlet means to the outlet means of said duct;
said blower and said duct together constituting means effective, when said circulator is disposed in the space, to establish a fast moving, unconstrained column of air extending from said outlet means towards the top of the space and effective to induce substantial quantities of secondary air into said column; and said blower having a capacity such that the density of air at the top of said column is substantially reduced over the density of air at the bottom of said column.
an upright air flow directing duct;
air inlet means at a lower portion of said duct;
upwardly facing air outlet means at the top of said duct; and a blower for moving primary air from the inlet means to the outlet means of said duct;
said blower and said duct together constituting means effective, when said circulator is disposed in the space, to establish a fast moving, unconstrained column of air extending from said outlet means towards the top of the space and effective to induce substantial quantities of secondary air into said column; and said blower having a capacity such that the density of air at the top of said column is substantially reduced over the density of air at the bottom of said column.
2. An air circulator as claimed in claim 1 which is free standing and has means for supporting said duct upon a floor, said outlet means being spaced from said supporting means such that when said circulator is disposed in the confined space a spacing of a height at least equal to that of said air circulator remains between said outlet means and the top of said confined space.
3. An air circulator as claimed in claim 1, wherein said inlet means comprises at least one inlet opening presented outwardly with respect to said air flow duct.
4. An air circulator as claimed in claim 1, wherein filter means are arranged near said inlet means and grating means are arranged near said outlet means.
5. An air circulator as claimed in claim 4 wherein said air flow duct is of generally square transverse cross-section and is mounted upon support legs.
6. An air circulator as claimed in claim 1, wherein said air circulator further comprises:
air channelling means for channelling air through the upper part of the air flow duct.
air channelling means for channelling air through the upper part of the air flow duct.
7. An air circulator as claimed in claim 6, wherein said air channelling means is composed of a plurality of ducts.
8. An air circulator as claimed in claim 6, wherein said air channelling means is a single circular duct.
9. An air circulator as claimed in claim 1, wherein said blower comprises a fan having a plurality of propeller blades and a motor for driving said fan, said fan being mounted in said air flow directing duct with said blades extending transversely of said duct and a baffle plate extending transversely of said duct and having an aperture in which said blades are rotatable.
10. A method of conserving heating energy in the heating of a confined space which comprises:
disposing an air circulator on a floor of the space, the air circulator having an air flow directing duct with an air inlet means at a lower portion of the said duct and an upwardly facing air outlet means at the top of said duct and a blower moving primary air from said inlet means to said outlet means;
said air outlet being spaced a substantial distance from the top of the space; and ?
operating said blower in such a way that a fast moving column of primary air extending from the outlet means towards the top of the space is established;
said column issuing from said air outlet means at a speed to cause substantial quantities of secondary air to the induced into said column from a region of the space between said air outlet means and the top of the room so that a resultant mixture of primary air and secondary air reaching the upper regions of the space has a density substantially less than the density of air at the bottom of the column, thus substantially limiting the extent to which the air delivered to the top of the space by the circulator can fall towards the floor.
disposing an air circulator on a floor of the space, the air circulator having an air flow directing duct with an air inlet means at a lower portion of the said duct and an upwardly facing air outlet means at the top of said duct and a blower moving primary air from said inlet means to said outlet means;
said air outlet being spaced a substantial distance from the top of the space; and ?
operating said blower in such a way that a fast moving column of primary air extending from the outlet means towards the top of the space is established;
said column issuing from said air outlet means at a speed to cause substantial quantities of secondary air to the induced into said column from a region of the space between said air outlet means and the top of the room so that a resultant mixture of primary air and secondary air reaching the upper regions of the space has a density substantially less than the density of air at the bottom of the column, thus substantially limiting the extent to which the air delivered to the top of the space by the circulator can fall towards the floor.
11. A method as claimed in claim 10, wherein the primary air is moved from said inlet means to said outlet means by said blower at a speed of at least 800 feet per minute.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US91297378A | 1978-06-05 | 1978-06-05 | |
| US912,973 | 1978-06-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1137350A true CA1137350A (en) | 1982-12-14 |
Family
ID=25432788
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000310307A Expired CA1137350A (en) | 1978-06-05 | 1978-08-30 | Air circulator |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1137350A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2468498A (en) * | 2009-03-11 | 2010-09-15 | Duncan Charles Thomson | Floor mounted mobile air circulator |
-
1978
- 1978-08-30 CA CA000310307A patent/CA1137350A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2468498A (en) * | 2009-03-11 | 2010-09-15 | Duncan Charles Thomson | Floor mounted mobile air circulator |
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