US2737977A - High pressure converter - Google Patents

Description

March 13, 1956 E. J. Kum-:K

HIGH PRESSURE CONVERTER Egg' 5 j@ PEfSSf Etg March 13, 1956 E. J. KUREK HIGH PRESSURE CONVERTER 5 Sheets-Sheet 5 Filed July 50, 1953 GSE SQ N www? Sv wN MN Twill SSQ .Q lw f NW QN hh RN RWRV RN WJNH Y 1 mw wm mf Nk ,Wk NN Nw w l QR www QQ ,um Mm R h W mm United States Patent() HIGH PRESSURE CONVERTER Edwin I. Kurek, Chicago, Ill., assignor to The Pyle- National Company, Chicago, Ill., a corporation of New Jersey Application July 30, 1953, Serial No. 371,389

9 Claims. (Cl. 137-561) This invention relates generally to Ventilating apparatus and more particularly to a Ventilating system of the type comprising duct means providing a fluid circuit and including a main supply duct in the circuit receiving the discharge from a blower means at one point in the circuit provided to pressurize a supply of Ventilating uid to pressures in excess of atmospheric pressure, thereby to drive a stream of Ventilating uid into the main air supply duct and through the circuit. Flow restriction means are located at points in the circuit downstream of the pressurizing means to transitorily depress the pressure of the uid to a pressure less than the pressure upstream of each respective point but greater than the atmospheric pressure so that branch duct means in the circuit at'each point will receive a quantity of Ventilating fluid from the main air supply duct at the corresponding transitorily depressed pressure. Return duct means are provided'for the system to carry return fluid to the blower means. Fresh air inlet means into the circuit can also be provided.

The disclosure of the present application constitutes a continuation-impart of my copending application U. S. Serial No. 232,554, filed June 20, 1951.

Recent developments in the Ventilating art have indicated a trend toward the utilization of comparatively high pressure fluid in a Ventilating system comprising a network t of air ducts. In such systems the main trunk will be provided which is adapted to carry a stream of Ventilating air pressurized to a value as high as 5 or 6 inches of water gauge. Connected to the main trunk will be a plurality of branches each having separate low pressure air diffusion means. In order to bleedoif selected quantities of air from the main trunk into each respective branch duct system, it is necessary to utilize some form of pressure conversion means between each branch andthe main trunk.

In the devices heretofore provided for effecting such pressure conversion, serious deficiencies have been manifested. lt will be apparent that it is highly desirable to provide an adjustable form of pressure conversion means so that the entire Ventilating system network can be adequately balanced. Moreover, the pressure conversion means should be of simplied design and should comprise a reduced number of simplified elements which are easy to install and maintain and which may be. serviced by relatively inexperienced personnel.

Moreover, the pressure conversion means should operate quietly, `without whistling and should operate efficiently to bleed oii only as much air as is required in each respective branch.

It is an object of the present invention, therefore, to provide a Ventilating system of the character described wherein a network of air ducts is provided including a main trunk and a plurality of branch ducts and wherein improved pressure conversion means are utilized.

It is a particular object of the present invention to provide pressure conversion means which overcome the deciencies heretofore manifested by the prior art devices.

Another object of thepresent invention is to provide a 2,737,977 Patented Mar. 13, 1956 pressure conversion means wherein male andfemale members provide a tiuid restriction passage having a structural ow contour to produce a local transitory depression of pressure in a fluid path so that selective quantities of air at positive gauge pressure may be bled off from the uid path into a branch duct system.

Yet another object of the present invention is to provide ow restriction means including a tlexible wall device and adjustable tluid delivery means whereby a resultantV profile may be selectively adjusted to vary the quantitative amount of transitory depression in a fluid path. i

A further object of the present `invention is to `provide a flow restriction means wherein an axial adjustable plug movable in upstream or downstream direction may be utilized to vary the quantitative amount of transitory depression with respect to a bleed-off opening.

Another object of the present invention is to provide pressure conversion means utilizing a ccntractable nozzle.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings in which a preferredstructural embodiment incorporating the principles of the present invention is shown by way of illustrative example' only.

On Vthe drawings:

Figure l is a composite Schematic View showing in the upper portion thereof a diagrammatic View of a conversion mechanism utilizing a contractable nozzle provided in accordance with the principles of the present inven tion and indicating in the lower portion thereof the variations in pressure occurring within the conversion mechanism, wherein the curves represent the velocity pressure, the static pressure, and the total pressure variations along the conversion mechanism.

Figure 2 is a composite schematic view showing in the upper portion thereof a diagrammatic View of a conversion mechanism utilizing an adjustable plug providing an adjustable flow restriction means of graduated divergence and convergence in accordance with the principles of the present invention and indicating in the lower portion thereof the variations in pressure occurring within the conversion mechanism.

Figure `3 illustrates one embodiment of the present invention wherein an adjustable plug is utilized;

Figure 4 is a cross-sectional view partly diagrammatic showing a contractable nozzle provided in accordance with the principles of the present invention;

Figure 5 is a cross-sectional View with parts shown in elevation and with parts shown diagrammatically showing a pressure conversion means provided in accordance with the principles of the present invention and utilizing an adjustable plug means providing an annular nozzle j in a flow path; and

Figure 6 is a cross-sectional View of another embodiment of a pressure conversionmeans in accordance with the principles of the present invention and shows, partly diagrammatically, a Ventilating system utilizing a contractable nozzle.

As shown on the drawings:

As is well known, air ow through any given section 0f duct work is characterized by the relationships of pressure and velocity. The sum of velocity and static pressure at any given duct section is called the total pressure. Total pressure is highest at the discharge of the pressurizing means and lowest at the outlet of the duct system where it is equal to the velocity head, the static pressure having been reduced to zero relative to the atmosphere by frictional losses. Although velocity and static heads are mutually convertible, their sum must always equal the total pressure for any given flow section.

By using an eiciently designed nozzle or a similar'ow n restriction means, it is possible to convert a high static, high velocity pressure stream to a low static and higher velocity stream in or at the restriction, such as at the throat of the nozzle.

Moreover, by providing an after section in such a system, the velocity of the stream will be decreased due to the reexpansion of the ilow area thereby resulting in a regaining of some of the initial static pressure.

In accordance with the principles of the present invention, the static pressure of an air stream in a duct is temporarily depressed in the vicinity of a lateral orifice through the reduction of the duct area, thereby rendering possible the bleeding off of variable quantities of air at conveniently low pressures. Thereafter, the original duct area is restored in such a manner as to reestablish substantially the original static pressure for ow to the next bleed-off point.

In my copending application, Serial No. 232,554, filed June 20, 1951, there is disclosed a slidable nozzle which can be moved relative to the lateral orifice so as to impose across the orice variable static pressures from a maximum available static pressure to a minimum static pressure in excess of the back pressure at the bleed-cti point. In this manner, the output of the lateral orice is controlled.

In the present disclosure, there is provided means for varying the cross-sectional area of the flow path across the duct at a lixed point in the duct which may comprise a streamlined plug which is movable longitudinally relative to a lateral orice, the plug having a nozzle prole so as to provide a ow restriction throat forming means in the duct which will transitorily depress the fluid pressure in the ow path in the vicinity of the lateral opening to a pressure lower than the pressure upstream of the opening but higher than the back pressure in the opening. A contractable nozzle is also provided in accordance with the present disclosure and will function in a similar manner to produce similar results.

In Figure l there is shown diagrammatically a pressure conversion device 10 having a contractable nozzle 11 located in a main air supply duct 12 of uniform crosssection. A lateral bleed-oit opening 13 is provided in the main air supply duct 12 and is connected to a branch duct 14 which, in accordance with the principles of the present invention may comprise branch duct of a plurality of L,

mospheric pressure against -flow conditions or characterr istics through the pressure conversion means. Longitudinally spaced points in the pressure conversion means correspond to spaced points on the X co-ordinate of the graph. Thus, the point 1 on the main air supply duct 12 corresponds to point 1 as indicated on the graph. At point 1, the total pressure indicated by Pi comprises a velocity component indicated by the legend Pv and a static pressure component which is indicated by the legend Ps.

Since the main air supply duct 12 is of uniform crosssection, these values remain substantially constant until point 2 is reached, the beginning of the ilow restriction means provided by the contractable nozzle 11.

Point 3 on the main air supply duct 12 and on the graph of Figure 1 corresponds to the smallest cross-sectional area of the contractable nozzle 11 and it will be noted that between point 2 and point 3, the curve Pv will rise and the curve Ps will fall, thereby indicating the action of the contractable nozzle 11 in transitorily depressing the fluid pressure in the ow path.

Point 4 on the main air supply duct 12 and on the graph of Figure 1 corresponds to the center line of the lateral bleed-off opening 13 and point 5 on the main air supply duct 12 and on the graph of Figure 1 is located downstream of the lateral bleed-off opening 13 a sufiicient distance so that the velocity of the stream has decreased due to the enlargement ot the ow area downstream of the nozzle and so that there will be some regain of the initial static pressure.

The widest opening through the contractable nozzle 11 shown in Figure l is indicated as the dimension A. For this position of the contractable nozzle 11, the cuive Ps will toliow that portion of the curve indicated by Psa. Likewise, the curve Pv will follow that portion of the curve indicated by Pvz. Under these conditions7 the static pressure gauge available at the lateral bleed-ofic opening 13 (point 4 on the graph) for purposes of bleeding ofi a quantity of air will be equal to the value a. lt is understood, of course, that bleed-ott into the branch duct 1f@ will not occur unless the pressure therein is less than the value a' which, as indicated, is measured at gauge above atmospheric.

if it is desired to bleed-ott smaller quantities of air at the lateral bleed-oit opening 13, the contractable nozzle 11 may be adjusted to assume the nozzle profile corresponding to the dimension identified by B. Under these conditions, the curves will follow the portions indicated Pvb and Psp and the static pressure (gauge above atmospheric) available at the bleed-off opening 13 (point 4 on the graph) will be indicated by the dimension b.

To obtain a minimum bleed-oit, the profile of the contractable nozzle 11 may be adjusted to the position of smallest cross-sectional area indicated by the dimension C, thereby moving the curves to the portions indicated at Pvc and Psc. Under these conditions, the static pressure available (point 4 on the graph) will be equal to c.

It will be understood that the curve PT indicating total pressure will vary and to indicate on the graph of Figure 1 such variance and particularly to demonstrate the decreasing amounts of regain, the curve PT is shown as following the portions P'rc, Prb and Pira, respectively.

In Figure 2 a main air supply duct 12 has brackets 16 and 17 spaced on opposite sides or" the lateral bleedoff opening 13 and a support rod 18 extends therebetween to slidably carry a rigid plug 19 prescribing a nozzle prole alternately diverging and converging so as to provide a streamlined contour. The plug 19 is moved longitudinally so as to adjust in upstream and downstream direction with respect to the lateral bloedof opening 13, thereby adjusting the quantitative value of transitory depression for varying the quantity of air or fluid bled off into the branch duct M.

ln the arrangement of Figure 2, the plug 19 is illustrated as being in three different positions labeled a, [1 and c. In the graph of Figure 2, it will be noted that the respective curves are displaced longitudinally with respect to the lateral bleed-off opening 13, thereby varying the quantitative amount of transitory static depression in the locale of the laterai bleed-off opening 13 so as to adjust the amount of air bled oit into the branch duct 14 from the main air supply duct 12. Again, it will be understood, of course, that bleed-off into the branch duct 14 will not occur unless the pressure therein is less than the pressure available for bleed-ofiv which, as is indicated, is measured at gauge above atmospheric.

Referring now to Figures 3-6, various structural embodiments incorporating the principles of the present invention are shown. In Figure 3 is provided a ventilating system 20 comprising a network of air ducts including a main air supply duct or main trunk 21 carrying pressurized Ventilating air supplied thereto by a fan or a blower means 22 having an outlet 23 and an inlet 24, the outlet 23 being connected to the main air supply duct or main trunk 21 as at 26.

The Ventilating system network further comprises a plurality of branches each having separate low pressure air diiusion means, one of the branches being indicated at 247. Each of the branches is connected to 'the main trunk 21 at a lateral bleed-off opening 28.

Return duct means 29 carry return air back to the fan or blower means 22, Since the blower means outlet is connected to the main air supply duct 21 and since the return air means 29 are connected to the blower means inlet 24there is provided a iluid circuit through which` a stream of Ventilating air may be driven at pressures in excess of atmospheric pressure. Fresh air inlet means are also indicated .at 25 to introduce fresh air into the circuit in supplementation of the return air. The term return air is used herein as it is commonly used in the heating and Ventilating arts, the return air means 29 being merely a diagrammatic representation of a conventional return air arrangement as commonly utilized in the normal air circuit of a circulating air type heating or Ventilating system.

In accordance with the principles of the present invention, pressure conversion means are provided at each bleed-off point so as to bleed oil selected quantities of Ventilating fluid from the main air supply duct 21 into each of the respective branch duct means 27.

In the embodiment ofl Figure 3, the main air supply duct 21 comprises a female member and there is also provided a male member 30 which cooperate together to form a ilow restriction passage in the main trunk having a structural Viiow contour to produce a local transitory depression of static pressure in the main trunk at the locale of the lateral bleed-off opening 28.

More specifically, the pressure conversion means of Figure 3 include a rigid plug constituting the male member 30 and having a curved circumferentially continuous peripheral surface 31 shaped to provide the graduated diverging and converging profile of substantially a teardrop contour. There is also provided on the plug or male member 30 a plurality of circumferentially spaced radially outwardly extending tins or ribs 32 secured thereto as by welding 35 or any other suitable fastening means which are adapted to slidably engage the walls of the main air supply duct or main trunk 21.

Adjustment means are also provided to lock the plug or male member 3i) in selected positions relative to the lateral bleed-off opening 28. In this connection, an elongated longitudinal slot 33 is formed in the wall of the main air supply duct 21 or main trunk and a threaded aperture 34 is provided in one of the -ribs or tins 32, thereby to lie in register with portions of the slot 33.

A fastener 36 is provided with a threaded portion 37 threadedly engaging the walls of the recess 34 and a` washer 38 is provided to be interposed between the fas- 21 or main ytrunk 21. Thus, the plug or male member 3i) is selectively adjusted and may be locked in adjusted position by turning up the fastener 36 after passing the nut 36 through the washer 38, through the slot 33 and into the threaded aperture 34 in the rib or iin 32. be understood that the plug or male member 30 is adjusted relative to the lateral bleed-oit opening 2S to transitorily depress the uid pressure in the ilow path through the main air supply duct 21 to a pressure lower than the pressure upstream of the bleed-oi opening 28 but higher than the back pressure in the branch duct 27.

In the embodiment of Figure 4, the LVentilating system network also comprises the blower means 22 having the outlet 23,`the inlet 24 and the main air supply duct or main trunk 41. A duct connection 26 is provided to discharge pressurized Ventilating iluid from the blower means 22 into the main air supply duct 41. Return duct means 29 are also provided which are connected to the blower means inlet 24. The main air supply duct 41 is provided with a lateral bleed-off opening 42 communicating with a branch duct 43 adapted to supply air to dittusion means.

Upstream of the bleed-oft opening 42 a T-shaped conduit 44 is provided, the long leg of the T-shaped conduit 44 being indicated at 46 and extending longitudinally of lt will ti the main air supply duct 41 substantiallyl coaxially thereof and past the lateral bleed-olf opening 42.

The opposed end legs of the T-shaped conduit 44 extend laterally of the main air supply duct 41 and one of the legs is connected toI a source of pressure indicated at 47 by means of a conduit 48 controlled by a valve 49. A plug means for varying the cross-sectional area of the flow path across the duct is indicated generally at 50 and comprises llexible Wall means 51 taking the form of a tlexible sleeve or rubber sleeve having reduced neck portions 52 at opposite ends thereof` and an enlarged medial section 53 forming ailuid tight chamber 54. The reduced neck portions of the sleeve 51 are clamped securely by means of clamp 56 to spaced apart points on the leg 46 and openings 57 are provided in the leg 46 to conduct a control fluid into the chamber 54.

Upon adjusting the valve 49, pressurized iluid is delivered through the T-shaped conduit 44 into the chamber 54 so as to adjustably flex the sleeve 51 radially outwardly, thereby to selectively forma graduated diverging and convergingprole to transitorily depress the iluid pressure in the flow path at the vicinity of the bleed-olf opening 42 to a pressure lower than the pressure upstream of the opening 42 but higher than the back pressure in the branch duct 43.

In the embodiment 0f Figure 5, the main air supply duct is indicated at 60 and is provided with a lateral bleed-off opening 61 communicating with a branch duct 62. At opposite sides of the lateral bleed-oilopening 61 are provided diametrically extending support members 63 and 64.

A support rod 66 is stationarily supported within the main air supply duct 60, preferably coaxially therewith and a ow restriction means comprising a plug means is slidably carried by the support rod 66 in the fluid path for adjustment in upstream and downstream direction relative to said lateral bleed-off opening 6l.

The plug means is indicated at 67 and provides a profile 68 of graduated divergence and convergence to transitorily depress the fluid pressure in the flow path at the locale of the bleed-oil opening 61 to a value lower than the pressure upstream of the opening but higher than the back pressure in the branch duct 62.

To adjust the position of the plug means 67, a hollow tube 69 is firmly connected as at 7i) to the plug means and is slidably supported by the support member 64. A bracket member 71 is iirmly attached to the tube 69 and registers with a slot 72 'which is elongated in longitudinal direction in one wall of the main air supply duct 60. A locking member 73 threadedly engages the bracket member 71 and may-be drawn up tightly to loci; the plug means 67 in any adjusted position relative to the lateral bleedo1 opening 61.

In the embodiment of Figure 6, a main air supply duct is provided with a recess 81 in the walls thereof seating a plug means 82 for varying the cross-sectional area of the flow path across the duct taking the form of a flexible sleeve, for example, a rubber sleeve 83. The end or' the sleeve 83 is shown connected to the main supply duct St) by means of a connecting strap 85 and suitable fasteners 84.

The other end of the sleeve $3 is shown overlapping -the edges of a lateral bleed-off opening 86 formed in the main air supply duct Si). The lateral bleed-oit opening S6 communicates with a branch duct S7 providing wall means backing up the edges ofthe sleeve 83. A mounting flange 88 engages the sleeve 83 and suitable fasteners 89 are provided to clamp the end of the sleeve in ihm assembly with the walls of the duct Work.

There is thus provided between the walls of the main air supply duct 80 and the sleeve 83 a control chamber 90 which is adapted to receive a pressurized control fluid so as to selectively ex the walls of the sleeve 83 radially inwardly.

To control the admission of pressurized fluid from the pressure source 47 through the conduit 48, the control valve 49 is connected to a nipple 91 opening into the control chamber 90 and attached to the walls of the main air supply duct 80 by a flange 92 and suitable fastencrs 93. The Valve 49 is also provided with a pressure release means indicated at 94 so that the pressure in the control chamber 90 may be effectively regulated.

When the flexible walls provided by the sleeve 83 are moved radially inwardly by delivering fluid pressure into the control chamber 90, the size of the flow path will be restricted, By varying the degree of restriction, it is possible to adjust the quantitative amount of transitory depression at the locale. of the bleedo opening 86. A proper adjustment is made to transitorily depress the fluid pressure in the flow path through the main air supply duct 80 at the bleed-olf opening 86 to a pressure lower than the pressure upstream of the opening 86 but higher than the back pressure in the branch duct 87.

Although Various minor structural modilications might be suggested by those versed in the art in connection` with the preferred structural embodiment herein described by way of illustrative example, it should be understood that I wish to embody within the scope of the patent warranted here all such modilications as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. In a Ventilating apparatus, a supply duct for carrying an air stream at an appreciable velocity from an upstream source exhibiting a total pressure appreciably above atmospheric pressure to a downstream zone exhibiting a lesser total pressure, said duct having upstream and downstream duct portions of substantially equal cross-sectional area, and means in saidV duct between said upstream and downstream portions for varying the cross-sectional area of the flew path across the duct at a lixed point in said duct, whereby the static pressure and the velocity pressure components of the total pressure of the airstream are mutually converted at said point and are reconverted in a discrete zone in said duct extending downstream from said point, and means forming an opening in said duct at said discrete zone providing a Ventilating air outlet for supplying Ventilating air to a point of utilization, the relationship of the reduced cross-sectional area and the cross-sectional area of said duct and the relationship of the axial distance between said point and said opening being such that the static pressure inside of said duct at said opening is maintained in excess of the pressure outside of said duct at said opening, thereby to bleed a quantity of air from said duct outwardly through said opening.

2. In a Ventilating apparatus as defined in claim 1, said means for varying the cross-sectional area comprising a rigid plug having a peripheral surface shaped to form a proiile of graduated divergence from one end towards an intermediate portion and convergence from the intermediate portion towards the other end, and means for adjusting said plug in upstream and downstream direction with respect to said opening, whereby the quantum of excess pressure at said opening may be varied.

3. In a Ventilating apparatus as dened in claim l, said means for varying the cross-sectional area comprising a plug having llexible peripheral walls and means for adjusting said walls to adjust the prolile of said plug by positioning said exible walls to Vary said cross-sectional area of the flow path across the duct, thereby to vary the quantum of excess pressure at said opening.

4. In a Ventilating apparatus as detined in claim 1, said means for varying the cross-sectional area comprising an annular exible wall connected to said duct and adjustable radially inwardly to form an adjustable profile of graduated divergence and convergence, and means for acting upon said flexible wall to vary the said cross-sectional area of the liow path across said duct, thereby to vary the quantum or" excess pressure at said opening.

5. ln a Ventilating apparatus as defined in claim 1, said means for Varying the cross-sectional area comprising means forming an annular flexible wall spaced inwardly of the walls of said duct, and means for adjusting said wall radially outwardly to vary the degree of graduated divergence and convergence of the proiile formed by said flexible wall, thereby to vary the quantum of excess pressure at said opening.

6. In a Ventilating apparatus as dened in claim 2, said adjustment means including slide track means in said duct supporting said plug for movement and locking means to tix said plug in adjusted positions.

7. In a Ventilating apparatus as defined in claim 3, said lug comprising a rubber sleeve forming together with said duct an annular liuid control chamber, said adjustment means comprising fluid control means delivering liuid into said chamber to vary the prolile of said rubber sleeve.

8. in a Ventilating apparatus as defined in claim 3, said plug comprising a hollow rubber member having a luid chamber formed therein, said adjustment means comprising liuid control means delivering fluid into said chamber to vary the profile of said rubber member.

9. ln a Ventilating apparatus as dened in claim 1, said means for varying the cross-sectional area comprising a plug member having a profile of substantially tear-drop contour, radially outwardly extending tins secured on said plug member slidably engaging said duct means to support said plug member for movement, and adjustment means to lock said plug member in adjusted positions with respect to said opening, whereby the quantum of excess pressure at said opening may be varied.

References Cited in the tile of this patent UNITED STATES PATENTS 174,781 Clemens Mar. 14, 1876 570,903 Callahan Nov. 10, 1896 1,279,739 Merrill Sept. 24, 1918 1,559,057 Stewart Oct. 27, 1925 1,786,969 Van Der Heuel Dec. 30, 1930 2,123,440 Schlafman Iuly l2, 1938 2,182,686 Young Dec. 5, 1939 2,240,119 Montgomery et al Apr. 29, 1941 2,372,830 Honerkamp et al Apr. 3, 1945 2,590,215 Sausa Mar. 25, 1952 2,598,208 Bailey May 27, 1952 2,609,743 Ashley et al Sept. 9, 1952 2,660,946 Peple, lr Dec. 1, 1953 FOREIGN PATENTS 554,115 France June 5, 1923

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