US2843036A - Exhaust fan means - Google Patents

Description

July 15, 1958 QUICK I 2,843,036

' EXHAUST FAN MEANS Filed Sept. 27, 1954 WIIW" 7/1- I INVENTOR. THOMAS E. QUICK A TTOPMFY EXHAUST FAN MEANS Thomas E. Quick, Wichita, Kans- Application September 27, 1954, Serial No. 458,554- 4 Claims. (Cl. 98-43) This invention relates to fluid flow. In a more specific aspect, this invention relates to moving a relatively large mass of the fluid very etficiently at low velocity. In a still more specific aspect, this invention relates to exhaust fan means, particularly useful in an outside wall or partition to move a large mass of air at low velocity from the inside to the outside of a room or from one room to another, one of the particularly important features of the apparatus being its induced air movement feature.

In my co-pending application Serial No. 375,894, filed August 24, 1953, now abandoned, I disclose and claim new fluid moving means embodied in a fan particularly desirably used to move and circulate air within a room or building. The new impeller means disclosed and described therein is substantially similar to the impeller means embodied in the new exhaust fan means disclosed and claimed in this application which is a continuation-in-part of my prior filed pending application.

In many industrial, commercial and home buildings today, it is desirable to change the air in the building or a room of the building without creating strong drafts, for example, air conditioned structures in which the air is recirculatedand heat removed therefrom, or in a room requiring constant fresh air make up where the inherent leaks in the building around the windows, doors, etc., cannot be relied on for such make up, particularly if the room or building is of any appreciable size. Also, in many industrial plants, it is desirable because of contamination to change the air in a building or plant more than that realized by the usual leakage, for example, chemical plants with which obnoxious gases are usually associated. Of course, since the problem is not one of rapid movement of air to gain the advantages of a cooling fan type function, it is desirable that the air be moved at a relatively low velocity from the space in question. Such air movement operations are more important today than in any time in our commercial and structural past, and it is becoming more important all the time. There are, of course, means known in the art which will exhaust air from space represented by rooms'or buildings, and these include blade type fans, centrifugal blowers, and these devices used with cooperating apparatus to induce air exhaust by utilization of a primary air stream. The devices of the prior art are ineflicient because they do not provide for streamline flow, and they are noisy, being undesirable where noise is a problem and where it is disturbing to occupants in or out of the room or building. I have invented very eflicient and noiseless exhaust fan means particularly desirably used in outside walls or partition walls to exhaust air from a space within a room or building.

The new exhaust fan means of my'invention has an impeller with means to actuate the impeller. Fins are disposed on the impeller in the direction of the desired fluid flow, which is preferably from within the room or building to without the room or building through the wall thereof. The tins of the impeller are preferably 2,843,036 Patented July 15, 1958 deeper at the fluid intake end portion than at the fluid discharge end portion of the impeller. The impeller is housed with a housing member therearound and the impeller and housing define primary fluid passageway. My device uses at least one other housing, preferably mounted around the impeller housing and forming therewith an induced fluid passageway. The apparatus has means which is adapted so that the primary fluid flow of the device induces the fluid flow in the induced fluid passageway. In a preferred specific embodiment of the new exhaust fan means of my invention, the mdividual induced and primary fluid passageways have inlet areas greater than their outlet areas.

The new exhaust fan means of my invention has many advantages over those means of the prior art. My new means is extremely eflicient, and when used to exhaust air from a building or a room, it delivers a large mass of air outside at very low velocity. No drafts are encountered within the room or building during operation. However, the new'device of my invention is easily adapted to variation and design so that if desired, the air can be exhausted at relatively high velocities. The new exhaust fan means of my invention is practically noiseless, the relative air flow being parallel to the blades of the impeller. The new exhaust means of my invention is indeed a step forward in the art and offers a highly eflicient and noiseless means of better controlling air conditioning which is an important feature of buildings today.

It is an object of my invention to provide new fluid moving means.

It is another object of my invention to provide new fluid moving means with induced fluid movement features which is particularly advantageously used to move a large mass of air at relatively low velocity.

It is still another object of my invention to provide new exhaust fan means for wall or partition installation to exhaust air from a building or roof efliciently, noiselessly, and without creating drafts within the space of the room or building.

Other objects and advantages of my invention will become apparent upon reading this disclosure.

Drawings accompany and are a part of this disclosure. Such drawings depict preferred specific embodiments of the new exhaust fan means of my invention, and it is to be understood that these drawings are not to unduly limit the scope of my invention.

In the drawings, Fig. 1 is a plan view partly in cross section and partly cut away showing a preferred specific embodiment of my new exhaust fan means mounted in a wall.

Fig. 2 is an elevation view of the exterior of the new fan means shown in Fig. 1 taken on line 22 of Fig. 1.

Fig. 3 is an elevation view of the fan means depicted in Fig. 1 from the inlet thereof with the fan means mounted in a wall.

Fig. 4 is a plan view partly in cross section and partly cut away illustrating another preferred specific embodiment of the new exhaust fan means of my invention mounted in a wall.

Following is a discussion and description of the new exhaust fan means of my invention. The discussion and description is made with reference to the drawings whereon the same reference numerals are used to indicate the same parts or structure. The discussion and description is of preferred specific embodiments of my invention, and it is to be understood that such is not to unduly limit the scope of my invention.

The new exhaust fan means of my invention is mounted in a wall 5, which can be an outside wall of a building, if air is to be moved from the inside to the outside of my invention. The frusto-conoidal members forming the induced air passageways 7 and the primary duct 9 can be mounted in wall in any suitable manner, and are preferably supported and spaced one from the other by struts 11 which are preferably made streamlined. As one skilled in the art can see, the assembly of Fig. 4 can be mounted and supported in the same manner as that shown in Figs. 1, 2 and 3. The air flows from the inside to the outside through the induced and primary air passageways, and it is preferred that these passageways 7 and 9 have a larger inlet area than their outlet area at the restricted point in the wall 5, increase in size beyond the Wall to discharge being preferable to handle the total volume of primary and induced fluid to discharge the air at low velocity and to make the apparatus efiicient. This has been found to result in high efficiency, moving a maximum amount of air from inside to outside with a minimum of energy expended. The frusto-conoidal members forming the passageways can be made of any suitable material. I prefer that they be constructed of metal or plastic so that they are rigid and maintain their desired shape and spacing as shown.

The impeller means of my invention has a cone-shaped body portion 13 mounted on a drive shaft 15 of electric motor means 17 which powers the impeller. This conical body 13 defines primary air passageway 9 with the frustoconoidal housing adjacent and around the impeller. The conical member 13 has a plurality of impeller fins l9 longitudinally disposed on the face thereof in the direction of desired air flow. These impeller fins preferably are deeper at the apex endportion of cone 13 than at the base portion thereof, as shown.

In the embodiment of Figs. 1, 2 and 3, a frusto-conoidal or mushroom-shaped housing 21 is mounted apex end to wall 5, and with wall 5 and the frusto-conoidal duct members forms a peripheral discharge outlet for the air exhausted by the fan means. This housing member 21 along with the outer plate 23 houses motor means 17, the motor preferably being mounted therein by nut and bolt means, as shown. The frusto-conoidal housing 21 is preferably of shape and size to provide a streamline surface to direct air discharge from the impeller and primary duct 9 out through the peripheral discharge opening. This has been found to result in efiicient and practically noiseless operation. Housing 21 having motor means 17 mounted therein and in turn mounting impeller body 13, can be mounted on the wall 5 in any suitable manner. I find that spacing and strut members 25 are very satisfactory to secure the assembly to wall 5, screws 2'7 being used to removably mount the back plate 23 and housing 21 to struts 25. This has been found to be very advan tageous, since if repairs are necessary the movable assembly can be easily removed fro-m the rest of the fan means. The other ends of struts or support members 25 can be secured to the wall 5 in any suitable manner, such as by nailing or with brackets and screws, and the like. In the embodiment of Fig. 4, it is provided that the combined stream of primary and induced air is discharged axially. The outer duct defining induced air passageway 7 is extended beyond wall 5 and with streamline housing 29 forms the annular air discharge.

In operation, the impeller 13 having fins 19 is retated by motor means 17 and air moves into and through the primary air passageway 9 defined by the inner frusto-conoidal member and cone shaped impeller body 13. The resulting primary air stream discharged toward the outside passes over the outer ends of induced air passageways 7 and through the throat of the apparatus causing reduction in pressure and a. flow of air through ducts 7 from inside wall 5 to the outside thereof. The combined air streams then pass outwardly and out through the peripheral opening formed by housing 21 and wall 5 in the embodiment of Fig. l, and out through the annular discharge opening around housing 2.9 of the apparatus of Fig. 4. The result is a very eificient movement of a large mass of air from the inside to the outside, such air discharging at low velocity. Any number of induced air ducts can be employed, as desired. It a relatively strong draft is desired, the number and size of induced air ducts can be small, for example, the one of the embodiment of Fig. 4. I have found the installation depicted in Figs. 1, 2 and 3 of the drawings to be very eflicient to noiselessly move air in large quantities at low velocity, which is desirable in air change for make up required in air conditioned installations, and for air change to eliminate obnoxious odors and air contaminants.

The prior art teaches and shows that centrifugal force has been used to increase the velocity of air in a radial direction, for example, by use of the so-called squirrel cage blower, and the centrifugal pump. But as a result of my invention, centrifugal force is directly utilized to create difference in pressure to move and accelerate fluids in axial direction, thus centrifugal force is for the first time used to move fluids axially. The energy possessed by the axially moving air through the impeller and the ducts of the means of my invention results from the centrifugal force exerted by the impeller, such producing a low pressure on the face of the conical portion of the impeller. This creates a pressure differential, and air is forced into this low pressure area with a force equal to the centrifugal force. Thus, the axial activating force is substantially equal to this centrifugal force, and centrifugal force has been directly utilized to effect axial flow of fluids.

As will be evident to those skilled in the art, various modifications of this invention can be made, or followed, in the light of this disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the claims.

I claim:

1. An exhaust fan comprising, in combination: an outer fixed frusto-conoidal shaped duct adapted to be mounted in an outside or partition wall; a plurality of inner fixed frusto-conoidal shaped ducts coaxially mounted within said outer duct to form-a central primary fluid duct and a plurality of outer induced fluid ducts; a rotatable coneshaped impeller coaxially mounted in said central duct to form an annular passageway therewith, said passageway and induced air ducts having inlets of greater area than their outlets; a plurality of radially extending, thin and flat fins longitudinally disposed on said impeller at right angles thereto and parallel to the axis thereof, said fins having a greater area toward the apex than the base of said impeller and forming said impeller adapted upon operation to centrifugally move air axially; a streamline frusto-conoidal shaped housing member mounted apex end to said wall on tthe outside thereof, said housing member forming with said ducts and said wall a passageway to induce fluid flow through said induced fluid ducts upon operation of said impeller with primary fluid passing over the outlets of said induced fluid ducts, and forming a peripheral fluid discharge opening; motor means to actuate said impeller mounted in said housing; and means to mount said exhaust fan means in said wall.

2. An exhaust fan comprising, in combination, an outer fixed duct adapted to be mounted in a wall, an inner fixed duct mounted within said outer duct to form an induced fluid passageway therewith, a rotatable conoidal impeller axially mounted in said inner duct to form a primary fluid passageway therewith, said induced and primary fluid passageways having inlet areas greater than their outlet areas, a plurality of radially extending, thin and flat fins longitudinally disposed on said impeller at right angles thereto and parallel to the axis thereof, said fins being deeper toward the apex than the base of said impeller and forming said impeller adapted upon operation to centrifugally move air axially, a housing member constructed to form with said ducts and said wall a passageway across the outlet of said induced fluid passageway to induce fluid flow through said induced fluid passageway upon operation of said impeller with primary fluid passing over the outlet of said induced fluid passageway, and forming a peripheral fluid discharge, and motor means to actuate said impeller mounted in said housing.

3. An exhaust fan for a Wall comprising, in combination, an outer fixed induced fluid passageway, an inner fixed duct, said passageway and duct converging and then diverging from front to rear, a rotatable conoidal impeller axially mounted in said inner duct to form a pri mary fluid passageway therewith, a plurality of radially extending, thin and flat fins longitudinally disposed on said impeller at right angles thereto and parallel to the axis thereof, said fins being deeper toward the apex than toward the base of said impeller and forming said impeller adapted upon operation to centrifugally move air axially, means constructed to form with said wall a passageway across the outlet of said induced fluid passageway to induce fluid flow through said induced fluid passageway with primary fluid by directing said primary fluid upon operation of said impeller across the outlet of said induced fluid passageway, and forming a fluid discharge, and means to actuate said impeller.

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4. Fluid moving means, comprising, in combination, a fixed converging, diverging primary duct, an impeller axially mounted within said primary duct, said impeller having a conoidal central portion with a plurality of centrifugally acting longitudinal blades radially projecting therefrom which are deeper in their forward portions than their rear port ons, means to operate said impeller, an outer fixed converging, diverging duct forming with said primary duct an induced flow passageway having the outlet positioned to received thereacross fluid discharged from said primary duct, and said impeller adapted upon operation to centrifugally move fluid axially through said primary duct and over the outlet of said induced flow passageway to induce fluid flow therethrough.

References Dited in the file of this patent UNITED STATES PATENTS 383,217 Fox May 22, 1888 879,476 Krell Feb. 18, 1908 1,363,959 Davidson Dec. 28, 1920 1,408,715 Seelig et a1 Mar. 7, 1922 1,767,988 Knapp June 24, 1930 1,889,117 Adamcikas et al Nov. 29, 1932 2,469,820 Fuge May 10, 1949 2,544,379 Davenport Mar. 6, 1951 FOREIGN PATENTS 396,547 France Apr. 14, 1909

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