US3086696A - Fan - Google Patents

Description

April 3, 1963 R. HElNE-GELDERN 3,086,696

FAN

Filed Jan. 26, 1961 2 Sheets-Sheet l INVENTOR.

ROBERT HEINE-GELDERN -8w \LDOQA/ 061! ATTORNEYS April 3, 1963 R. HElNE-GELDERN 3,086,696

FAN

2 Sheets-Sheet 2 Filed Jan. 26, 1961 3,086,696 FAN Robert Heine-Seldom, Upper Montclair, N.J., assignor to Engelhard Hanovia, Inc., Newark, N.J., a corporation of New Jersey Filed .lan. 26, 1961, Ser. No. 85,013 2 (Ilaims. (Cl. 230-42) This invention relates to ventilators or fans for conveying fluids, generally air or other gases, from one zone into another zone. Ventilators may be used in industrial plants, or for providing aeration of large or small rooms, such as apartments. More particularly, this invention is concerned with ventilators of the type termed line fiow fans, and has for its main object the improvement of such devices by increasing the efficiency thereof and eliminating most of the noise produced by them under operating conditions. The invention also includes arrangements for reversing the direction of flow without reversing the direction of rotation of the driving mechanism, as is the case with conventional screw-type window fans.

'Line flow fans are ventilators in which the element driving the fluid, generally air, is an assembly of parallel, elongated, arcuate blades in a cylindrical arrangement and secured to a pair of circular end plates to form a rotor of cylindrical shape. Such rotors are conventional in the prior art and have generally the shape of an elongated cylinder, the ratio between the lentgh of the axis and the diameter of the end plates being immaterial insofar as the performance of the device is concerned. Short or long cylindrical rotors may be used, in accordance with specific requirements. By way of example, in conjunction with window fans for household purposes, the rotor is mounted in a casing dimensioned to fit into the frame of a window in a horizontal direction, with the rotor being slightly shorter to accommodate the side portions of the housing, a driving motor and other components forming part of the complete device.

A line flow fan includes, furthermore, guide surfaces which define the shape of the conduit through which the air is conveyed. Although the rotor assembly is generally the same, guide surfaces formed by elements termed baffles or vanes of various shapes have been suggested in prior art devices.

Such guide surfaces are a necessary requirement be cause a line flow fan rotor, when driven to rotate within an open space of air, produces only turbulence without conveying air from one predetermined zone into another. In the case of a window fan, the first mentioned zone is the outer atmosphere and the second the air in the room.

Heretofore, it was believed that at least two bafiles are required which, usually arranged to encompass the rotor at substantially opposite locations with respect to the rotor axis, separate an inlet zone from an outlet zone. Generally, it was also considered necessary that at least one of the baffles extend over a considerable peripheral area of the rotor, and this bafiie was mounted along the circumference of the cylindrical rotor where the blades re-enter the inlet zone from the outlet zone. As a result, the blades facing the baffle extending over a significant area of the periphery at any given instant during operation, do not constitute a part of either the inlet section or the outlet section. desired effect but merely operate to return air from the outlet to the inlet zone, which result constitutes a loss.

Bellies forming guide surfaces are a necessary requirement, as discussed above. However, each bafile arranged closely adjacent the rotor causes turbulence which, in turn, leads to loss of energy and, therefore, to a decrease They do not contribute to the 3,666,696 Patented Apr. 23, 1963 ice in efficiency. As another, even less desirable result, each turbulence around a bafile produces noise. This fact is of great importance in conjunction with, for example, window fans.

It has been found that a fan rotor of the type described above, when combined with only one bafile arranged closely adjacent the rotor to separate the outlet area from the inlet area, with all other guide surfaces considerably spaced away from the rotor, exhibits an efficiency which at least equals that of conventional fans with more than one baflle mounted adjacent the rotor. Moreover, as compared to such conventional fans or ventilators, the noise produced under otherwise equal conditions is considerably reduced. As a further advantage, the baffles used to form the guide surfaces may be adjustable so that only one of them is maintained in a close spatial relationship with respect to the rotor, while the remainder is positioned away from the rotor. By shifting the location at which a single bafile is in close relationship with the rotor circumference, the direction of flow can be controlled. With a shift of about the flow direction is reversed, which is accomplished by adjusting the bafl les and the guide surfaces formed by them.

At this point it should be noted that the surfaces delimiting the conduit through which air is conveyed necessarily include side walls which extend perpendicularly with respect to the rotor axis and generally in a close spatial relationship with respect to the circular end plates forming part of the rotor. Such side walls, although they assist in defining the air conduit, are not considered guide surfaces or bafiles in the meaning of these terms, as used herein.

Accordingly, the present invention is directed to a device of the type which includes a cylindrical line flow fan rotor for conveying a fluid, in combination with only one baffle positioned closely adjacent the rotor cylinder over an axially extending narrow area of the cylinder. The remaining, practically entire rotor cylinder surface remains exposed to a significant continuous volume within the conduit through which air is conveyed. As a result, the efliciency is increased because practically all of the rotor blades contribute to the desired effect, while the production of noise is reduced to a minimum occurring in the area of only one bafile mounted adjacent the rotor, instead of at least two bafiles used in prior art devices.

In practice, a fan according to the invention includes bafiles one edge of which, preferably of a thickness not exceeding the distance between each pair of adjacent rotor blades, is mounted closely adjacent the rotor cylinder surface over an axially extending area. This edge separates the inlet from the outlet area at a location where air returns from the outlet into the inlet area. At the generally opposite side of the rotor axis, a by pass zone outside the rotor and leading from the inlet to the outlet zone remains open. While a gradient of air velocity decreasing from the rotor toward the guide surface is established in this by-pass area, it ha been found that no losses of energy occur as a result of this arrangement. On the other hand, the absence of any second edge or baflle positioned closely adjacent the rotor was found to avoid any additional source of turbulence and noise, so that the fan of this invention operates significantly quieter than devices suggested heretofore.

The fact that a fan according to this invention operates with only one baffle, such as an edge of a suitable guide surface assembly which is mounted closely adjacent the cylindrical rotor surface, results in another important feature. Adjustable baffle arrangements may be provided for shifting the bafile edge from one predetermined location to another, in order to modify or to reverse the air fiow direction, Thereby the use of expensive reversible'lotric motors, employed heretofore in conjunction with conventional screw-type ventilators, is avoided. In other words,-the invention includes the provision of adjustable baflies, for regulating the flow of air through the fan by controlling the relationship between. flow conditions along one side of the rotor with respect to flow conditions at another side of the rotor.

In practice, the arrangement for achieving such control may include at least two bafile members and appropriate elements, such as a lever system, for selective ly adjusting either of the bafiles toa position closely adjacent an axially extending area of the cylindrical rotor, with the other bafile member being maintained spaced from the rotor.

' While it is possible to provide a mechanism for shifting the rotor axis by a parallel movement to a position closely adjacent either of stationary guide surfaces,

it has been found more economical to provide adjustable. bathe or guide surface assemblies, with the rotor axis re-' m'aining stationary.

The invention will be further illustrated by reference to the following more detailed description of one embodiment of the invention and the accompanying drawing,

inwhich V FIGURES 1 and 2 are schematic sectional views through a line flow fan, illustrating one of the underlying principles of the invention;

FIGURES 3 and 4 are sectional views, similar to those of FIGURES 1 and 2, showing the principle of one emhodiment of a bafiie arrangement;

FIGURE 5 is a fragmentary cross-section through a line flow fan illustrating a portion of the mechanism for shifting the battles of FIGURES 3 and 4 from one into the other position of FIGURES 3 and 4, respectively;

FIGURE 6 is a longitudinal sectional view through the ran along the line 6-6 of FIGURE 5 illustrating a lever system for shifting the baffles from the config'uration of FIGURE 3 to that of FIGURE 4; and

1 FIGURE 7 is a fragmentary perspective view of one end of a line flow fan illustrating details of FIGURES 5 and 6, with the rotor and the cover of the casing removed.

Referring now to FIGURES 1 and 2, these figures illustrate, in a purely schematic manner, one of the important underlying principles of this invention. Reference numeral 10 designates a conventional line tflow fan rotor-which comprises a plurality of elongated arcuate parallel blades 12 mounted in a cylindrical arrangement between, a pair of circular end walls (not shown in FIGURES I and 2). In accordance with the invention, under operating conditions and at any given moment, the. complete assembly includes only one baflie which is positioned closely adjacent the periphery of the rotor. The baffle is mounted closeto, but must not be in contact with any part of the rotor, as is conventional with battles forming guide surfaces and mounted in the vicinity ofthe rotor to define the conduit through which air is conveyed. In FIGURES 1 and 2, each of the figures illustrates a pair of baflies of the most simple shape which isthat of strips 14 and 16 adjacent therotor 10. The baflles 14 and 16 separate two zones from each other and, assuming that air is to be conveyed from the 'zone at the left-hand side of the drawing to that at the right-hand sideQthe spatial relationship betweeen the rotor and. each of the baffles is that shown in FIGURE 1. The rotor is driven to rotate in the directionof the arrow 18 and as shown in FIGURE 1. The baffle 14 mounted adjacent the rotor separates the inlet zone from the outlet zone at the location where the blades enter the first mentioned from the last mentioned zone. It can be seen from FIGURE 1 that the assembly includes only one baffle mounted closely adjacent the rotor, which is the strip 14, while the bafile 16 is maintained signifi a comparatively simple means for reversing the direction of flow by shifting the location in which the bafile is positioned closely adjacent the rotor from one prede: termined position to another. When shifting is effected to a position which is from the initial position, reversing of the flow occurs. In practice, and if desired, the angle of shift may be smaller or greater than 180, to result in a corresponding change of direction of flow.

The great number of conceivable mechanisms for shift: ing the bafiIe from one location to another may include various arrangements. In some instances, shifting the entire rotor by a parallel movement from the position shown in FIGURE 1 to that of FIGURE 2 may be accomplished. However, since fan rotors are generally driven by electric motors, and for other practical reasons, it has been found more suitable to provide an arrangement for shifting the bafiles from one position to the other, with the rotor remaining stationary. By way of example, both baffies 14 and 16 may be mechanically coupled to each other and to an adjusting mechanism, permitting them to assume the position of either FIGURE 1 or FIGURE 2 by a vertical movement toward or away from the rotor axis, respectively. The step of shifting the closely facing battle edge from one position to the othermay be accomplished by any other suitable means, such as rotating both bafiies about an axis which is eccentric vwth respect to the rotor axis.

Referring now to FIGURES 3 and 4, the novel concept is illustrated in a similar schematic fashion. The embodiment schematically illustrated therein is an adjustable bafflle arrangement which has been found suitable for Window fans or similar installations. In both of FIG- URES 3 and 4, the rotors are designated by reference numeral 10 and the arrows indicating identical sense of rotation of the rotor are designated 18. In most instances where fans are used for conveying air from one zone into another, the rotor is transversely mounted in a housing or casing which delimits a conduit through which air must be conveyed. When mounted within the casing, the rotor separates an inlet zone and an outlet zone in the casing and, upon reversal of the direction of the flow, the inlet zone becomes the outlet zone. The same is true for the inlet and outlet areas of rotor periphery which are the portions of the rotor facing either one or the other zone. Furthermore, the baflies forming guide surfaces controlling the flow of air through the conduit in the vicinity of the rotor may form part of the housing or they can be arranged Within the housing as distinct components.

Similarly as in FIGURES l and 2, FIGURES 3 and 4 schematically illustrate a baflle arrangement, regardless of whether or not the bafiies pertainto the housing.

Each of the bafiles includes a pair of elongated strips 20, 22 and 24, 26, respectively, joining one another at one of the longitudinal edges to provide a V-shaped configuration. All of them extend in a longitudinal parallel arrangement with the rotor 10, substantially over the entire length thereof. Strips 20 and 22 arejoined to each other at the longitudinal edges of the strips to form a hinge 28. Similarly, strips 24 and 26 form a second bafiie assembly with a hinge 30. A suitable mechanism for shifting each of the bafile assemblies from the position With the rotor turning in the same dior configuration shown in FIGURE 3 into the position shown in FIGURE 4 is described below.

In FIGURE 3, the joined edges of strips and 22 forming the hinge 28 perform in a manner analogous with that of the lower edge of baffle 14 in FIGURE 1. The surfaces of the strips 20, 22 facing the rotor are guide surfaces in the conventional meaning of the term. It can be seen that, in the position shown in FIGURE 3, the hinge 28 constitutes the only element of the bailie assembly positioned closely adjacent the rotor periphery, since both strips 24 and 26 forming the lower bafiie assembly in FIGURE 3 are maintained at a significant distance from the rotor. The hinge 28 clearly separates the outlet area of the rotor at the right-hand side of FIGURE 3 from the inlet area at the left-hand side. The zones communicate with each other by a by-pass area formed between the rotor and the bafile assembly 24-, 253. When propelled by the rotor, air flow-s through this area around the rotor.

Under operating conditions, a gradient of velocity will be established between the rotor and the lower baffle assembly in FIGURE 3, as indicated by the arrows 32 having diminishing lengths toward the bottom of the drawing. As pointed out above, this arrangement of a minimum of bafiles positioned closely adjacent the rotor results in a minimum noise production as compared to that with devices of the line flow fan type used heretofore.

In a manner similar to that described in connection with FIGURES 1 and 2, switching the baffle assemblies 20, 22 and 24, 26 from the configuration shown in FIG- URE 3 into that shown in FIGURE 4, results in a reversed direction of flow. An example of a shifting mechanism for producing such change of baffie configuration will be described in more detail in conjunction with FIG- URES 5 through 7.

The edges of battles 14 and 16 (FIGURES l and 2), as well as the hinges 23 and of the baflle assemblies (FIGURES 3 and 4) present a comparatively narrow area facing and extending over a genetrix of the rotor. As described above, it has been found that prior art baffles extending over a significant segment of the rotor periphery operate to render ineffective the number of blades faced by them. Furthermore, it is assumed that the air returning between each pair of adjacent blades from the outlet area to the inlet area is subject to additional turbulence resulting in an increased production of noise. Tests have shown that a narrow edge positioned closely adjacent the rotor cylinder improves the eificiency of the device and, in accordance with a preferred embodiment of the invention, the width of the baffle facing the rotor must not exceed the distance between adjacent blades. When this condition is fulfilled, each space between adjacent blades, when facing the bafie, simultaneously communicates at any given instance with both the inlet and outlet zones, regardless of the rotor position.

Referring now to FIGURES 5 through 7, a conventional line flow fan rotor 19, which includes blades 12 and circular end Walls 34 and as, is transversely mounted in an outer casing forming the conduit through which air must be conveyed. The casing is formed by a base plate 38, a cover 46 and side walls 42 and 44 Six slots are provided in each of the side walls 42 and 44 in an arrangement best shown in FIGURE 5. Two of the slots, designated 48 and 50, extend in a vertical direction and at opposite locations with respect to the rotor axis. These slots and matching slots 52 and 54 (FIGURE 6) provided in the other side wall 42 accommodate the end portion of pins 56 and 58. The pins are those forming part of the hinges by which baffle strips 20 and 22., and 24 and 26 are joined to each other. In accordance with the embodiment illustrated, the hinges around the pins are formed by cylindrically bent projections on each of the strips 20, 22, 24 and 26 in a conventional manner. By a parallel movement of, for example, pin '56 by shifting the ends of the pin from a low position in the slots 48 6 and 52 (FIGURES 5 and 6) into the high position in the slot (FIGURE 7), the hinge portion of the bafile assembly formed by strips 2% and 22 can selectively be brought to a position closely adjacent the rotor 10, as shown in FIGURE 3, or into the spaced position shown in FIGURE 4.

Each of the casing side walls 42 and 44 also includes two pairs of shorter slots, of which two slots, designated by reference numerals 60 and 62, are symmetrically arranged at both sides of slot 43. A pair of corresponding slots 64 and 66 is provided in an analogous arrangement with respect to slot 50. Each of the slots slidably accommodates one peg designated by reference numerals 68, 7t 72, and 74, respectively. The inner end of each of the pegs is split in a longitudinal direction and secured, for example by welding, to the bafile, while the outer end of the peg protrudes into the slot. It will be apparent that the peg-slot combination permits a pivoting movement combined with a horizontal, reciprocating movement of the area of each of the strips to which the peg is secured. Accordingly, by shifting the four ends of the pins 56 and 58 which protrude outwardly from the side walls 42 and 44 through slots 48, 5d, 52 and 54, each of the battle assemblies 20, 22, and 24, 26 will assume a roof-or V-shaped configuration pointing toward the rotor or away from it corresponding either to that shown in FIGURE 3 with the pins 56 and 5% being in the lowest position, or that of FIGURE 4 with the pins in the upper position.

Shifting the pins 56 and 58' and therewith the bafile as sembly from one to the other configuration or position with the roof pointing either toward or away from the rotor may be accomplished by any suitable arrangement, and a simplified structure for this purpose is illustrated in FIGURES 6 and 7. Such structure may include a bar 76 extending horizontally over a length exceeding that of the housing and continuing into two vertical arms 78 and 89, each arm having two bores therethrough, of which each receives one end of the pins 56 and 58. A handle 82 secured to the bar 76 permits effecting a reciprocating movement of the bar 76 and of the arms 78 and 80, whereby 'the four ends of the pins 56 and 58 slide in the slots 48, 50, 52 and 54, respectively. Thereby, the baffle assemblies assume either one or the other position, as discussed above. As a result, adjusting the handle 82 in either the highest or the lowest position will result in an air flow in either of the two directions through the fan, as described in connection with FIGURES 3 and 4.

Rotation of the rotor is conveniently accomplished in a conventional manner by means of an electric motor 84 and reversing the air flow is accomplished by activating the handle 8-2. The shaft 86 connecting the driving motor with the rotor end wall 36 is shown in the drawing to pass through a longitudinal slot 88 in the arm to permit actuating the shifting mechanism without interfering with the driving mechanism for the rotor.

In order to maintain the baffle assemblies in either of the selected positions, the device may include any conventional structure suitable for the purpose, such as fiat springs 90 and 92' mounted between and frictionally engaging the side walls 42 and 44 and the arms 78 and 80, respectively. Suitable different arrangements for maintaining the assembly in one or the other of both portions may be used. Such structures, as well as other arrangements for shifting the hinged edges of the bafile assemblies are known and need not be described in more detail.

It will be obvious that many more modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention in cludes all such modifications.

\Vhat is claimed is:

1. In a line flow fan, a plurality of parallel arcuate blades in a cylindrical arrangement forming a rotor, a pair of elongated bafile assemblies at generally opposite sides of the rotor to define a conduit through which air is conveyed, each baflie assembly including a pair of substantially flat elongated strips movably joined to each other atoms edge of each strip to form a hinge, linkage,

means interconnecting the hinges for simultaneously shifting one of the hinges selectively into a first position and the other hinge into a second position one hinge being in a close spatial relationship with the rotor surface when in the first position, and the other hinge being spaced away from the rotor when in the second position, and means for maintaining the edges of the strips remote from the hinges in a position spaced away from the rotor regardless of the hinge position, whereby each bafile assembly, when in the first position, forms a V- shaped separating bafiie pointing toward the rotor to separate an inlet zone from an outlet zone in the conduit, each bafile assembly, when in the second position, being entirely spaced from the rotor to leave a passageway from the inlet into the outlet zone and around the rotor.

2. ,In a line flow fan, a plurality of parallel arcuate 20 blades in a cylindrical arrangement forming a rotor, a

conduit through which air is conveyed encompassing the rotor, the conduit including a pair of side Walls, each side wall having a pair of slots therethrough, the slots extending substantially radially with respect to the rotor 25 axis at opposite sides thereof and facing a matching slot in the other side wall, the conduit also including a pair of bafiie assemblies, each assembly comprising a pair of flat elongated strips hinged to each other along one of the longitudinal'edges of each strip, apair of pins, each pin 30 forming one of the hinges, each end of said pin passing through one of the slots to permit radial shifting each of the pins associated with one baffle assembly selectively toward and'away from the rotor axis, a pair of pegs secured to each of the strips, a slot in a side wall associated with each peg, the peg slidably protruding into the slot associated therewith, whereby four pairs of retaining members cooperating with the side walls are formed which permit a pivoting movement of the bafiie strips around an axis spaced from the hinge so that each of the baflie assemblies is adapted to assume either of two positions corresponding to first and second positions of the pin ends at the end oi the slots, with the bafie assemblies being maintained in a V-shaped configuration in either of the positions, the V-shaped baflle assembly pointing toward the rotor axis with the hinge being maintained in a close spatial relationship with respect to the rotor surface in the first position, the hinge and both strips being spaced away from the rotor in the second position, first means for shifting both ends of one pin associated with one hinge from one end of the corresponding slot to the other end of the slot to produce a shifting in baflle configuration from the firstposition to the second position, and second means, mechanically coupled with the first means, for simultaneouslyshifting the pin associated with the other bafile assembly in the same direction to produce a change in the baflie configuration from the second to the first position, each shifting from one into the other position resulting in a change of direction of the air flow.

References Cited in the file of this patent UNITED STATES PATENTS Germany Dec. 3, 1959

Claims (1)

1. 2. IN A LINE FLOW FAN, A PLURALITY OF PARALLEL ARCUATE BLADES IN A CYLINDRICAL ARRANGEMENT FORMING A ROTOR, A CONDUIT THROUGH WHICH AIR IS CONVEYED ENCOMPASSING THE ROTOR, THE CONDUIT INCLUDING A PAIR OF SIDE WALLS, EACH SIDE WALL HAVING A PAIR OF SLOTS THERETHROUGH, THE SLOTS EXTENDING SUBSTANTIALLY RADIALLY WITH RESPECT TO THE ROTOR AXIS AT OPPOSITE SIDES THEREOF AND FACING A MATCHING SLOT IN THE OTHER SIDE WALL, THE CONDUIT ALSO INCLUDING A PAIR OF BAFFLE ASSEMBLIES, EACH ASSEMBLY COMPRISING A PAIR OF FLAT ELONGATED STRIPS HINGED TO EACH OTHER ALONG ONE OF THE LONGITUDINAL EDGES OF EACH STRIP, A PAIR OF PINS, EACH PIN FORMING ONE OF THE HINGES, EACH END OF SAID PIN PASSING THROUGH ONE OF THE SLOTS TO PERMIT RADIAL SHIFTING EACH OF THE PINS ASSOCIATED WITH ONE BAFFLE ASSEMBLY SELECTIVELY TOWARD AND AWAY FROM THE ROTOR AXIS, A PAIR OF PEGS SECURED TO EACH OF THE STRIPS, A SLOT IN A SIDE WALL ASSOCIATED WITH EACH PEG, THE PEG SLIDABLY PROTRUDING INTO THE SLOT ASSOCIATED THEREWITH, WHEREBY FOUR PAIRS OF RETAINING MEMBERS COOPERATING WITH THE SIDE WALLS ARE FORMED WHICH PERMIT A PIVOTING MOVEMENT OF THE BAFFLE STRIPS AROUND AN AXIS SPACED FROM THE HINGE SO THAT EACH OF THE BAFFLE ASSEMBLIES IS ADAPTED TO ASSUME EITHER OF TWO POSITIONS CORRESPONDING TO FIRST AND SECOND POSITIONS OF THE PIN ENDS AT THE END OF THE SLOTS, WITH THE BAFFLE ASSEMBLIES BEING MAINTAINED IN A V-SHAPED CONFIGURATION IN EITHER OF THE POSITIONS, THE V-SHAPED BAFFLE ASSEMBLY

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