US2882928A - Constant delivery self-controlling device - Google Patents

Description

M. COGLIATI April 21, 1959 CONSTANT DELIVERY SELF-CONTROLLING DEVICE 4 Sheets-Sheet 1 Filed Oct. 26, 1954 2,882,928 CONSTANT DELIVERY SELF-CONTROLLING DEVICE Filed Oct. 26, 1954 April 21, 1959 M. COGLlATl 4 Sheets-Sheet 2 Fig.5-

M. COGLIATI April 21, 1959 CONSTANT DELIVERY SELF-CONTROLLING DEVICE Filed Oct. 26, 1954 4 Sheets-Sheet 5 M w I FVET? m 1 M r F a a F M u 11E: 11 T M E K m L" D 6 I, M F 11 i:: 2 1%. Mm u B A M. COGLIATI April 21, 1959 CONSTANT DELIVERY SELF-CONTROLLING DEVICE Filed Oct. 26, 1954 4 Sheets-Sheet 4 INVENTOR.

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Attorney United States Patent CONSTANT DELIVERY SELF-CONTROLLING DEVICE Marco Cogliati, Rome, Italy Application October 26, 1954, Serial No. 464,819 Claims priority application Italy October 31, 1953 12 Claims. (Cl. 137-578) This invention relates to a simple and reliable automatic device suitable to deliver from a container, containing water at variable levels, and generally containing any liquid at variable levels, with a determined constant delivery.

The problem is well known in that it interests a very large field of industrial and agricultural activities, such as the aqueducts, the irrigation networks, the hydraulic and hydro-electric installations and the like; however, up to now no general hydraulic solution has been attained, but only some roughly approximated solutions providing for mechanical pieces, such as levers, pivots, bearings, gearings, and the like, producing variable friction stresses affecting the final result. Moreover, most of said devices are often submitted to seizings in their operation due to immaterial causes, such as a leaf, a little sand, a little deposit, and so on; other devices require delivery escapes in the form of permanent escapes in order to be able to operate.

On the contrary, the self regulating device according to the present invention, provides no mechanical element such as levers, bell cranks, pivots etc. giving rise to friction, and consequently said device is very simple and produces no substantial friction; furthermore it checks any delivery escape, operating thus in a prompt and correct way.

The stationary part of said device consists of two superposed containers, communicating between themselves by means of a hollow cylinder, the axis whereof is vertical, passing through the horizontal division diaphragm. The upper container, or modulating basin, is fed by the container wherein there is the variable level water; the lower container, or distributing basin receives from the preceding basin the constant delivery and discharges same outside of the apparatus.

The movable portion of this self controlling device is formed by two hollow cylinders, the diameters whereof are slightly different from one another, said cylinders having the same vertical axis and being fixed to an upper ring and open downwards, so as to create under said ring an annular clearance between said cylinders. On the ring there is an overflow edge where the derivation of the constant delivery occurs. Both the cylinders fixed to the ring and the overflow edge are rendered rigid to a floater by means of beams and the unit forms a movable unit which is inserted on the stationary cylinder and exactly follows the level variations into the modulating basin: the derived delivery on the overflow edge is discharged through the distributing basin.

A pneumatic joint exists in the annular clearance between the movable cylinders, said joint being in permanent communication, by means of a pipe, with a supplemental container called balancer which keeps constant the pneumatic pressure of the air mass herein trapped: said joint has a very important function as it prevents the formation of any escape delivery between the movable cylinders and the stationary cylinder. The

2,882,92 Patented Apr. 21, 1959 movable unit, due to the absence of any friction in the system, therefore promptly and exactly follows any level variation; on the other hand, any escape is checked and as the floating conditions are, as it will be hereinafter described, always the same, the apparatus discharges through the overflow edge an absolutely constant delivery.

In the attached drawings:

Fig. 1 shows the axial cross-sectional view of the operating self controlling device, the feeding water being at its minimum level A;

Fig. 2 shows the corresponding plan view;

Fig. 3 shows an axial cross-sectional view similar to that of Fig. 1, with the water at its maximum level the corresponding plan view being equal to that of Fig. 2;

Fig. 4 shows a fractional axial sectional view, showing the positions of the movable unit in full operation, at the minimum level A (dotted line) and at an intermediate level (solid line) B;

Figs. 5 and 6 show the same fractional sections of Fig. 4, not superposed in order to allow a better examination of the variations occurring passing from a minimum level A to a desired average level B, and at the limit from the minimum level A to the maximum level C.

Figs. 7 and 8 are similar to Figs. 5 and 6, respectively, and illustrate a modified construction of the movable unit of the apparatus.

With reference to the Figs. 1, 2 and 3, the base 1 of the apparatus is also the bottom of the distributing basin 4 separated from the upper modulating basin 3 by the diaphragm 2, said upper basin 3 being fed by the piping 5 coming from the variable level container. The cylinder 6, fixed to the diaphragm 2 is upwardly and downinder 6, is downwardly open, such as an inverted cup and its lower edge is slightly spaced away on the intermediate bottom 2: the upper cover 10 is provided with a valve 11 allowing the supply of slightly compressed air when the apparatus is started operating, both to the balancer and to the clearance between the cylinders 13 and 14 with which the balancer is constantly communicating by means of the pipe 12.

The cylinders,13 and 14 of at their lower end and are welded at their upper end, in a perfectly sealed way, to the ring 15 which is upwardly provided with an outflow edge, in order to allow the air to freely enter under the stream of the outflowing water. Four spokes 16, 17, 18 and 19 connect the ring 15 to the threaded hub wherein is screwed and fixed, after having been adjusted, the sleeve 21 rigid with the spokes 22, 23, 24 and 25 which in turn are fixed to the floater 26. The ends of the spokes 23 and 25 are ring shaped, at 27 and 28, and are fitted on the small vertical guide rods 29 and 30, reducing materially and without substantial friction, the eventual eccentricity which the movable unit could have in respect to the stationary cylinder 6. However, as the self controlling device operates in a perfect manner also if the movable unit, with out the rings 27 and 28 is free to rotate and to reach from time to time the maximum eccentricity corresponding to the position wherein the movable cylinders 13 and 14 contact the stationary cylinder 6, the elements 27,- 28, 29 and 30 are no indispensable elements and therefore their use is suggested by particular considerations, as for instance the need of non-turning of the floater, the aspect the movable unit are open of the floating unit in order that said unit appear always as a well centered unit, and the like.

The area of the free section of the balancing cylinder 9 has been chosen equal to that of the base annular ring of the hollow cylinder G of Fig. 6: in turn said annular ring is determined by the outer diameters of the hollow cylinders 6 and 13. Thus, due to the communication provided by the pipe 12, it is easy to ascertain, for a the water has reached the maximum level C of Fig. 3,

a main delivery will be obtained on the upper edge of the ring 15, but in the same time another escape delivery, by annular syphon between the cylinders 14, 6, 13, will be started, so as to effect the total delivery on the edge 8.

If at a certain moment of this starting operation of the device, air is blown through the valve 11, said air is stored under the ring 15, and proceeding with said blowing, the arising water of the escape annular syphon will be depressed to the upper edge of the stationary cylinder 6. At said moment, the exact position of Fig. 3 will be reached, characterized by the total interception of any escape delivery: as a matter of fact, the annular column of the liquid cannot rise above the upper edge of the stationary cylinder 6, due to the pneumatic pressure of the mass of air stored under the ring 15, so that any escape delivery is totally intercepted. The apparatus is then in its final phase of correct operation, discharging only the main delivery by outflow on the upper edge, said delivery, after the adjustment being absolutely constant for whatever level of water within the modulating basin 3, as it will be hereinafter demonstrated.

Beginning from the position shown at Fig. 3: when the level C starts lowering reaching the desired average level B of Figs. 4 and 6, the small level between 14 and 6 and the level within the balancer 9 (which were before at the same distance from the upper'edge of 6, as at Fig. 3) will have reached the position B'. At said position the air trapped occupies the dome of the balancer over B'," the pipe 12 and the hollow cylindrical volumes E, F, G of Fig. 6.

The subsequent lowering of the feeding level of B to the minimum level A," carries the ring 15 to contact the upper edge of the cylinder 6 (Figs. 4 and and lowers the preceding levels from B' to A'. At this new position, the trapped air occupies the dome of the balancer over A, the pipe 12 and the volumes of the hollow cylinders E, F. In respect to the preceding situation there is, therefore, the volume increase of the dome of the balancer between B' and A' and the diminution of volume of the hollow cylinder G which disappeared; however the quality of the areas of the bases of the aforesaid two volumes, which have been hereinbefore described, as well as the equality of their,

. heights, demonstrate that the lost volume G has been exactly gained into the balancer between B' and A'.

Therefore the air occupies always the same total volume and as the mass is always the same, also its pressure will be constant for any water level into the modulating basin 3.

the water level. As far as the cylinder 13 is concerned,

since the level D of the water above the weir 8 is constant, the lower edgeof cylinder 13 receives a hydro- 4 static thrust which increases in proportion as the feeding level lowers to the minimum value A. Although the influence of said increasing of the thrust on the system of forces which determines the floating conditions of the movable unit is not important owing to the very small thickness of the cylinder, it may be desired to avoid said increasing of thrust.

For this purpose, the cylinder 13 may be made of two portions joined together as shown in Figs. 7 and 8. The upper portion 13a is connected to ring 15 in the same manner as the one piece cylinder 13 of Figs. 6 and 5. The lower portion 13b, near the level D of the water inside the space F is inserted by a desired amount into the upper portion 13a, then portions 13a and 13b are joined together to insure a suitable mounting and tight ness.

By this construction, there are the following conditions: (a) the upper portion 13a is never immersed under the level D," (Fig. 7) and therefore receives under its edge 32, for any position of the movable unit, always the same thrust due to the constant pneumatic pressure of the air in F; (b) the lower portion 13b, joined to the portion 13a, is totally immersed under the level D even if the feeding level reaches its maximum value C and receives therefore always the same hydrostatic thrust. Therefore on the cylinder 13 formed of two portions, for any level two thrusts are acting one of which exerted on the edge 32 is pneumatic and constant and the other is hydrostatic and equal to the dilfercnce between the hydrostatic thrusts on the edges 33 and 34; this difference is constant although the thrusts on the edges 33 and 34 are variable; as the thickness of the cylinders has no influence, it will be possible to provide self controlling devices having rather thick walls of the cylinders (for instance made of reinforced concrete), without introducing any errors in the floating conditions of the movable unit.

These floating conditions require that for any level of the water into the basin 3, the weight of the movable unit (which weight is obviously constant) be equal to the algebraical sum of all of the pneumatic and hydrostatic partial thrusts acting on the movable unit.

As the balancer keeps constant the pneumatic pressure of the trapped air, the thrusts of said air under the ring 15 and under the edge 32 of the upper portion 13a of the cylinder 13 will be constant: no other pneumatic thrust is present. The hydrostatic thrusts are: (a) the thrust under the edge 31 of the cylinder 14, which is constant as set forth above; (b) the thrust on the whole lower portion 13b of the cylinder 13, said thrust being always the same since said portion is totally immersed for any position of the movable unit; (0) the thrust on the floater 26 (floating force); (d) the thrust on the horizontal projection of the ring 15 due to the height h of the water outflowing on said ring: the thrust a is the only force downwardly directed, while the other forces are upwardly directed. Thus, since both the pneumatic and the hydrostatic thrusts (a) and (b) are constant, the algebraical sum of the thrusts (c) on the floater 26, and (d) on the ring 15, or better the difference between their absolute values, has to be kept constant. If the level C tends to rise owing to a greater immission of water in basin 3, the floater 26 rises and brings therewith ring 15, which, on the contrary, would tend to lower owing to the increase of level C. However, since the horizontal area of the floater 26 is noticeably greater than the horizontal area of ring 15, the result will be the raising of the floater 26 and ring 15 therewith until the height h of the flowing water is restored. Thus the movable unit is stabilized and the stabilization is the more rapid the greater is the horizontal area of floater 26.

As the outflowing height h is automatically kept constant, a strictly constant delivery is obtained for any level of the water within the modulating basin 3, and this is the purpose tobe attained by this invention.

It is not necessary to place the outflow edge in correspondence with the cylinder 13: said edge can also be arranged towards outside in correspondence with the cylinder 14, so as to form an upwards projection 36 of this latter. In this case the height of the outflow edge is sulficiently raised above the ring 15, so that the lower liquid portions of the outflowing stream are squarely detached from the edge, without adhering to any extent to the ring which is not chamferedz, the thrust (d) on the ring 15, which has been mentioned above, does not occur, and as the thrust on the floater, which is the sole thrust acting in this condition, must be constant, the floating line of the floater cannot change. The result is the same: the height h is strictly constant and also strictly constant is the delivery.

The water outflowing on the outflow edge drags a certain amount of air and when the liquid mass enters the distributing basin 4, a certain number of air bubbles are produced which arise and enter the clearance of the pneumatic joint. In order to avoid that the pressure of the mass of air contained within this joint, within thepipe 12 and within the dome of the balancer, build up due to the air bubbles coming from down upwards, a series of small :diametered holes 35 are provided in the cylinder 14, around and immediately under the level A: these holes act as pneumatic outflow in that they allow the excess of air to escape under the form of bubbles, so that for any level the pressure of the trapped air is always measured by the hydraulic column of the difference of levels AA or B-B (which is equal to the former) of Figs. 5 and 6.

Due to the continuous supply of the air bubbles, the air blow through the valve 11 when the operation of the device is started, is unnecessary provided that it is possible to wait (generally some hours) the slow but sure formation of the mass of air at the necessary pressure: said formation is completed only when the free surface of the water in the modulating basin starts sparkling due to the bubbles escaping from the aforecited pneumatic overflow. This pneumatic overflow protects the apparatus againstany failure due to variations of temperature. In fact, if at a certain level B of Fig. 6, an increase of the temperature of the trapped air occurs, a portion of said air will escape through the holes of the outflow, but the air remaining within the joint will always have the correct pressure, measured by the difference of Water levels BB. If the temperature is rapidly lowered, the initial shrinkage first occurs, but the supply of the air bubbles coming from down upwards in a continuous way immediately re-establishes the preceding correct position.

The aforedescribed device, disclosed in a preferred form of embodiment, can be embodied either totally or partially of metal, of plastics, of glass, sandstone, of reinforced concrete and variations can be brought thereto Without departing from the scope of the present invention. In fact it is anticipated that it is possible to substitute for the delivery outflow on the ring 15, as shown in Figs. 1, 3, 4, 5 and 6, the outflow edge whereof is in register with the cylinder 13, another outflow device, the edge whereof is in register with the cylinder 14, as aforesaid; also it is possible to substitute for the delivery outflow generally, a number of free openings with load at their top, upwardly extending either the cylinder 13 or the cylinder 14. Obviously these variations will be used at any suitable connection.

I claim:

1. A constant delivery self-controlling device without substantial friction and affording the total pneumatic checking of the escapes of the liquid to be delivered, which comprises an upper supply basin for the liquid at variable levels, a lower basin for the constant delivery of the liquid, the upper basin penetrating into the lower basin and being fixed thereto, an open vertical eflluent pipe contained in said supply basin and extending through the bottom thereof and penetrating the said lower delivery basin, said efliuent pipe being fixed to the bottom of the supply basin, a portion of the wall of the lower delivery basin being arranged in the shape of a free weir for delivery of liquid, the position of the horizontal edge of said weir being determined by the condition that the level of the liquid above said edge is slightly lower than the upper end of said elfluent pipe, a movable unit arranged in the said supply basin and comprising a floater and two coaxial cylinders each of which has a length and a diameter diflerent from the other and are adjustably connected to the floater and movable therewith, said cylinders defining an annular space therebetween to be filled with air, a ring in the shape of a free weir joining said cylinders and closing the upper end of said annular space, the cylinder of greater diameter having a length less than that of the cylinder of lesser diameter, the upper portion of the wall of the eflluent pipe extending into the annular space between the cylinders, said coaxial cylinders being arranged to move vertically with respect to said upper portion of the wall of the efiluent pipe, a balancer associated to the supply basin and fixed thereto, said balancer being in form of an upwardly closed air-containing cylinder provided with an air valve at the closed end, the air cylinder having a lower open end which extends into the said supply basin to a desired extent from the bottom of the latter, said balancer having the cross-section area equal to the cross-section area of the annular space defined by the outer diameter of the said movable cylinder of lesser diameter and the outer diameter of the said effluent pipe and being adapted to contain air under pressure, and a connecting pipe between the upper part of theair cylinder and the annular space defined by the two coaxial cylinders of the movable unit.

2. A device as claimed in claim 1, wherein said connecting pipe leads to an opening in the wall of the said effluent pipe.

3. A device as claimed in claim 1, wherein the ring joining the two coaxial cylinders of diiferent diameter is provided with a free weir at the side of the cylinder of lesser diameter.

4. A device as claimed in claim 1, wherein the ring joining the two coaxial movable cylinders of difierent diameter is provided with a free weir at the side of the cylinder of greater diameter.

5. A device as claimed in claim 1, wherein the horizontal area of the floater is greater than the horizontal area of the ring joining at their upper part the two coaxial cylinders adjustably connected to the floater.

6. A device as claimed in 'claim 1, wherein the upper edge of the movable cylinder of greater diameter extends higher than the upper edge of the movable cylinder of lesser diameter and is arranged as a weir for the liquid coming from the supply basin and entering the eflluent pipe.

7. A device as claimed in claim 1, wherein the upper edge of the movable cylinder of lesser diameter extends higher than the upper edge of the movable cylinder of greater diameter and is arranged as a weir for the liquid coming from the supply basin and entering the efliuent pipe.

8. A device as claimed in claim 7, wherein the movable cylinder of lesser diameter comprises two sections so positioned with respect to each other that the lower edge of the upper portion is always subject to the pressure of the air contained in the annular space between the two coaxial movable cylinders and the upper and lower edges of the lower section are always sunk in the liquid of the delivery basin during the vertical displacements of the movable cylinder of lesser diameter connected to the floater.

9. A device as claimed in claim 1, wherein the lower and the upper edges of the movable cylinder of greater diameter are positioned to always remain sunk into the liquid of the supply basin during the vertical displacement of the said cylinder adjustably connected to the floater.

' 10. A device as claimed in claim 1, wherein the movable cylinder of lesser diameter is positioned to keep its lower edge always sunk into the liquid of the delivery basin during the vertical displacement of the said cylinder adjustably connected to the floater.

ll. A device as claimed in claim 1, wherein the movable cylinder of greater diameter is provided with a plurality of holes in its lower portion, said holes being arranged to allow the escape of the air bubbles formed in the efiluent pipe, whereby the pressure or" the air contained in the space between the movable cylinders of different diameters is kept constant.

12. A constant delivery self-controlling device without substantial friction and afiording the total pneumatic checking of the escape of the liquid to be delivered, which comprises an upper supply basin for the liquid at variable levels, a lower basin for the delivery of the liquid, the upper basin penetrating into the lower basin and being fixed thereto, a vertical open effluent pipe contained in said supply basin and extending through the bottom thereof and penetrating the said lower delivery basin, said effiuent pipe being fixed to the bottom of the supply basin, a portion of the wall of the lower delivery basin being arranged in the shape of a free weir for constant delivery of liquid, the position of the horizontal edge of said weir being determined by the condition that the level of the liquid above the said edge is slightly lower than the upper end of said eflluent pipe, a movable unit arranged in the said supply basin and comprising a floater and two coaxial cylinders each of which has a length and a diameter difierent from the other and adjustably connected to the floater and movable therewith, said cylinders defining an annular space therebetween to be filled with air, a

ring in the shape of a free weir joining said cylinders together and closing at the upper end said annular space, the cylinder of greater diameter having a length less than that of the cylinder of lesser diameter, the upper portion of the wall of the efiluent pipe extending into the annular space between the cylinders, said coaxial cylinders being arranged to move vertically with respect to the said upper portion of the wall of the efiluent pipe, a balancer associated to the supply basin and fixed thereto, said balancer being in form of an upwardly closed aircontaining cylinder provided with an air valve at the closed end, the air cylinder having a lower open end which extends into the said supply basin to a desired extent from the bottom of the latter, said balancer having the cross section area equal to the cross section area of the annular space defined by the outer diameter of the said movable cylinder of lesser diameter and the outer diameter of the said effluent pipe and being adapted to contain air under pressure, and a connecting pipe between the upper part of the balancer and the annular space defined by'the two coaxial cylinders of the movable unit, said connecting pipe opening in a hole bored in the Wall of the said effiuent pipe, said movable cylinder of lesser diameter being formed of two sections the lower of which is partly inserted into the upper section.

References Cited in the file of this patent UNITED STATES PATENTS 289,877 Wilson Dec. 11, 1883 FOREIGN PATENTS 3,654 Great Britain Feb. 14, 1911

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