US1416295A - Rotary ventilator - Google Patents

Description

Patentefi y 16, 1922. 2 suns-sum 1.

..-..| lllll I l Ll l l ll'l llillll W. F. HIRSCHMAN.

ROTARY VENTILATOR- APPLICATION FILED SEPT- 13. 1920.

w. F. HIRSCHMAN. V

V ROTARY VENTILATOR.

APPLICATIQN FILED SEPT. 13. 1920.

. 1 41 2925 I Patented May16,1922.

2 SHEETSSHEET 2. if

all.

F BUFFALO, NEW YORK. t

ROTARY VENTILATOR.

Specification of Letters Patent.

Patented May 1%, 1922.

To all whom it may concern:

Be it known that I, VVLJLIAM F. Hinsoir- MAN, a citizen of the United States, esiding in Buffalo, in the county of Erie and State of New York, have invented new and useful Improvements in Rotary Ventilators, of which the following is a specification.

This invention relates to a rotary ventilator whereby the pressure of the wind or air currents is utilized to draw out or suck objectionable gases and foul air from the buildings, and to discharge the same into the outside atmosphere.

One of the objects of the invention is to produce a device of this character which will have the greatest pneumatic-dynamic efficiency for any given wind speed and which will furthermore operate at very low wind pressures. A further object of the invention is to produce a rotary ventilator which will prevent any entrance of rain intothe vent pipe, either when rotating or when standing still. A still further object of the invention is to prevent any possibility of a back draft down the vent pipe when the velocity of the wind is extremely high.

in the accompanying drawings:

Figure 1 is a side elevation of the improved rotary ventilator. Figure 2 is a medial section through the axis thereof. Figure 3 is a top plan of the same. Figure 1 is a fragmentary horizontal section looking up and taken on line 4-4i, Fig. 2. Figure 5 is also a fragmentary horizontal sec tion, but taken on line 55, of Fig. 2.

Similar characters of reference refer to like parts throughout the several views.

9 represents the usual vertical cylindrical vent pipe which is adapted to be connected to any of the piping of a ventilating system (not shown) from which foul air and objectionahle are drawn and dispelled into the outside air. It is customary to connect this vent pipe to the upper end of a chimney or vertical vent conduit which passes through and projects some distance above the roof of the building which is to be ventilated. Secured to the outer rim or upper edge of said vent pipe and flaring downwardly and outwardly therefrom is an annular deflection ring o skirt 10 which prevents any rising currents of air from curling up and over the upper edge of the vent pipe and thereby tending to cause a back draft down the vent pipe or at least iInpeding the proper flow of foul air from said pipe. Arranged within said vent pipe 9 and secured to the inner face thereof are a number of vertical web plates 11, whose inner ends are mutually connected together and collectively act as a support for a vertical hollow tube or hearing sleeve 12. This sleeve as well as the web plates 11 and also the vent pipe 9, are stationary at all times. Secured coaxially to the uppe and lower ends respectively of said bearing sleeve 12 are a pair of cup-shaped bearing casings 13 and 1% arranged to receive suitable ball bearings and races which anti-frictionally support a vertical rotatable shaft 15. The upper ball bearings which are received by the upper casing 13 carry. of course, only a radial load, whereas the ball. hearings in the lower casing 1 1 carry both a radial as well as a longitudinal, vertical loading.

Secured to the said vertical otatable shaft 15 and disposed coaxially with respect to the vent pipe 9, is a conical upwardly tapering rotary dome 16. The diameter of this dome is considerably greate than the diameter of the said vent pipe, and from its peripheral edge depends an annular, vertical flange or apron 17 whose lower edge extends some distance below the uppe edge of the vertical vent pipe 9. Secured t0 the lower inclined face of the rotary dome and arranged in a circumferential row are a considerable number of suction blades 18 each of which is inclined somewhat or arranged obliquely relatively to a perpendicula plane passing through the axis and through said suction blade so as to act in the manner of'an ordinary propeller blade. Each of these suction blades 18 is secured at its lower end to an annula stiffening ring 20 which is dis posed just above and adjacent to the aforementioned skirt 1() of the vent pipe 9, the adjacent faces of said skirt and said stiffening ring being substantially parallel to each other.

Connected integrally'to the inner ends of a relatively small number of the suction blades 18, are a number of centrifugal blades which are disposed perpendicularly, lying in planes which pass through the axis of rotation of the rotary dome. It will be noticed that the'suction blades 18 do not lie above the opening or hole of the vent pipe 10, but are disposed outwardly of the periphery thereof. These vertical, centrifugal blades 21, however extend radially inwardly over the rim of said vent pipe 9 and.

project beyond the periphery thereof and are disposed above the central opening of said vent pipe. The space above the upper edge of the vent pipe 9 and below the lower face of the dome 16 may be denominated a centrifugal chamber 25 inasmuch as the action of the air currents therein is analogous to the action in the centrifugal chamber of an ordinary centrifugal pump. It is very important however that the air which passes upwardly from the vent pipe into said centrifugal chamber 25 and thence downwardly past the suction blades 18, should not be impeded. It is for this reason that the centrifugal blades are much fewer in number than the suctions blades, it being permissible of course, to employ a quite large number of suction blades, inasmuch as the same are disposed a considerable distance outwardly of the axis of rotation of the rotary dome. Any interference of the particular aircurrents, which pass close to the axis of the dome, is furthermore minimized by cutting off each of the centrifugal blades 21 on a line which extends from the inner edge of the stiffening ring 20 up toward the apex of the dome. centrifugal blades only extend radially inwardly a suillicient distance to ensure that the air be caught up from the said centrifugal chamber 25 and ejected therefrom without, however, clogging up said centrifugal chamber or interfering with the free and efficient flow of air therethrough.

The rotation of the dome is accomplished by securing a number of propeller buckets or blades 26 to the upper inrlined face of the conical, rotary dome 16. For one half of the rotation of the dome these propeller blades are travelling of course, with the wind, and the remaining half rotation against the wind. The construction of the blade. when travelling with the wind involves obviously no difficulties. Therefore, we will deal with the blades when travelling against the wind, i. e., to the left as shown in Fig. 1. Each of these propeller bl adcs has its forward or leading edge 27 disposed substantially flush with the upper surface of the dome, while the main body of each blade extends rearwardly and upwardly from said leading edge and terminates in a trailing edge 28. The intermediate or central portion 30 of the leading edge of each propeller blade is pointed, i. e., it extends some distance forwardly of the rest of the leading er go 27. [By this construction the relatively static body of air which lies adjacent the front or outer face of each propeller blade when the blade is travelling against the wind is separated or opened up gradually, such an action being in accordance with accepted pneumatie-dynamic practice. The intermediate portion 31 of the trailing edge 28 of each propeller blade overhangs or ex- In thisv way, the said tends considerably further rearwardly than the rest of the said trailing edge. This prevents an undue vacuum from forming under the propeller blade when the same is travelling against the wind, as otherwise the rotation of the whole rotary dome would be retarded. This action results from the fact that (as the air starts to flow back over the trailing edge 28 when the blade is moving in the half revolution against the wind) the said air currents first curl over the outer ends of the trailing edge 28, during the time that a partial vacuum is still being formed behind the overhang 31 of the trailing edge. This causes a lateral flow of air toward the under part of the overhang. 31, thus effectively killing the vacuum under the entire rear faces of the propeller blades by reason of the lateral air currents so induced. On the other hand, when the propeller blade is travelling with the wind, this overhanging portion 31 cuts the air current and curls the same under the concave or propelling face of the propeller blade similarly to the manner in which the leading edge of an aeroplane wing deflects the air downwardly against the main body of the aeroplane wing.

In the operation,the entire dome is rotated by a number of propeller blades 26 whose leading edges 27 are pointed at 30 so as to enter the dead air easily while the central parts of the trailing edges 28 overhang at 31 so as to kill the vacuum under said'blades when said blades are travelling against the wind. The'foul air from the building which is to be ventilated, rises up the vent pipe 9 into the centrifugal chamber 25. Here it is caught up by a small number of centrifugal blades 21 which however do not project sufficiently into said centrifugal chamber as to impede the flow of air therethrough. Thence the air is deflected downwardly by a large number of suction blades 18 which propel the air in a manner similarly to an ordinary propeller blade, i. e., the blades being inclined to the path of the air flow. These suction blades are arranged entirely outside of the centrifugal compartment so as not to interfere with the flow of air therethrough, the circumferential area of air path being of course much greater where the air travels through the suction blades than it is near the center in the centrifugal chamber 25. The suction blades 18 are located a considerable distance above the lower edge of the annular apron 17 and the space intermediate of said apron and said vent pipe is thereby filled with compressed air which is moving downwardly. Thus any tendency of the outside wind to curl up behind the apron on the particular side which happens, at the time, to be lying toward the oncoming wind, is frustrated, because this wind would have to first rise a considerable distance before coming in contact with the suction blades. Before such an action can occur the dome 16 has had time to turn around sufficiently so that the pressure of the external rising air is lowered on the leeward side of the ventilator and the pressure of the downcoming air from the suction blades rendered sufficient to overcome this rising current. Upward currents of external air are also discouraged by means of the skirt 10 on the upper outer edge of the vent pipe. Thus the ventilator will operate properly even though its lubricating system be neglected so that it turns comparatively slowly. The ventilator will turn, however, in very light breezes, and at no time can any rain come into the vent pipe inasmuch as the same is completely covered.

I claim as my invention:

1. A rotary ventilator comprising a rotatable dome, and a propeller blade secured to said dome and having a pointed leading edge and a trailing edge which overhangs the outer surface of said dome, the intermediate portion thereof extending rearwardly more than the other parts of said trailing edge and said intermediate portion being located at a point substantially in circumferential alignment with said leading edge.

2. A rotary ventilator comprising a rotatable dome, and a propeller blade secured to said dome and having a pointed leading edge which is located intermediate of the axis and the periphery of said rotatable dome and which terminates flush with the surface of said rotatable dome, said propeller blade having a trailing edge which is disposed outwardly of the surface of said rotatable dome and overhangs rearwardly a line extending from the outer to the inner end of the blade at a point circumferentially in alignment with said leading edge.

3. r rotary ventilator comprising a conical rotatable dome, and a propeller blade whose leading edge is flush with the outer surface of said conical dome and extends forwardly at a point intermediate of the axis and the periphery of said dome, the main portion of said propeller blade extending rearwardly and outwardly away from said leading edge and terminating in a trailing edge which overhangs rearwa-rdly a line extending from the outer to the inner end of the blade at a point intermediate of the axis and the periphery of the dome, substantially as described.

4. A rotary ventilator comprising a vent pipe, a rotatable dome arranged above and covering the upper end of said vent pipe, a centrifugal blade disposed radially with respect to the axis of the rotatable dome and extending from the peripheral part of said dome inwardly over the upper end of said vent pipe.

5. A rotary ventilator comprising a vent pipe, a conical rotatable dome having a depending peripheral apron and mounted sufficiently above the upper end of said vent pipe so as to form a centrifugal chamber, and a vertically disposed flat centrifugal blade secured to the lower face of said dome and extending radially into said centrifugal chamber and over the edge of said vent pipe.

6. A. rotary ventilator comprising a vent pipe, a conical upwardly tapering dome mounted coaxially with respect to said vent pipe, a centrifugal blade secured to and extending vertically downwardly therefrom and having an inner edge which extends from approximately the upper rim of the vent pipe obliquely upwardly and inwardly toward the apex of said dome.

7. A rotary ventilator comprising a vent pipe, a conical upwardly tapering rotatable dome provided with an annular downwardly hanging apron which extends below the top of said vent pipe, and a plurality of suction blades secured to the lower face of said dome and disposed inwardly of said apron and outwardly of said vent pipe.

8. A rotary ventilator comprising a vent pipe, a rotatable dome arranged above the upper end of said vent pipe, a circumferential row of suction blades secured to the lower face of said dome and disposed outwardly of said vent pipe, and centrifugal blades extending inwardly over the rim of said vent pipe, said centrifugal blades being comparatively few in number while said suction blades are very numerous.

9. A rotary ventilator comprising a vertical vent pipe, a rotatable, conical dome mounted coaxially therewith and provided with a vertical peripheral apron extending below the upper end of said vent pipe, and a conical skirt secured to the rim of said vent pipe and projecting downwardly and outwardly therefrom.

10. A rotary ventilator comprising a vertical vent pipe, a rotatable conical dome extending below the upper end of said vent pipe and larger in diameter than said vent pipe, and a plurality of suction blades secured to said dome and reversing the direction of flow of the air from said vent pipe, causing said air to be forced vertically downwardly through the space intermediate of the outer face of the vent pipe and the inner face of the dome.

11. A rotary ventilator comprising a vent pipe, a rotatable dome, a stiffening ring arranged coaxially with respect to said dome, a plurality of suction blades and a number of centrifugal blades secured at opposite ends respectively to said stiffening ring and to said dome.

12. In a rotary ventilator, the combination of a vent pipe, a dome rotatably mounted on said vent pipe, a plurality of suction blades secured to said dome and disposed outwardly of said vent pipe, and centrifugal blades also secured to said dome but projecting inwardly over the rim of said vent pipe.

13. A rotary ventilator comprising a vent pipe, a rotatable dome mounted on said vent pipe and provided with an annular apron which depends from the periphery of said dome and which extends below the top of the vent pipe, and a plurality of suction blades secured to said dome above the lower end of said apron, the air from said vent pipe be ing discharged vertically downwardly from said suction blades and into the space below which lies intermediate of the outer face of the vent pipe and the inner face of the. said 15 dome mounted coaxially with respect to said '20 vent pipe, a plurality of suction blades secured to the lower face of said dome, and a stiffening ring secured to the lower ends of said blades and disposed adjacent to said skirt of said vent pipe.

WILLIAM F. HIRSCHMAN.

Images