US2028568A - Pump - Google Patents

Description

Jan, 21, W36, A. F. SHERZER 2,928,568

PUMP I Filed Oct; 3, 1932 s Sheets-Sheet; 2

l l l FHWIL'HH' Mml J; 21, 136 A. F. SHERZER PUMP Filed Oct. 5, 1932 s Sheets-Sheet s Patented Jan. 21, 1936 PATENT OFFICE PUMP Allen F. Sherzer, Ann Arbor, Mich. Application October 3, 1932, Serial No. 636,061

1 Claim.

The invention relates to pumps and has for one of its objects to provide a pump which is very simple in construction and relatively cheap to manufacture. Another object is to provide a pump which is highly efficient in operation and which for a given discharge of fluid at a given absolute velocity of discharge requires relatively low power for its operation. A further object is to provide a pump in which the total power in its outer end the discharge orifice 3.

expended may be variably divided between kinetic and potential energy, as desired.

These and other objects of the invention will become apparent from the following description, taken in connection with the accompanying drawings, in which Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 12 and 13 are diagrammatic sectional views illustrating embodiments of my invention;

Figure is a cross section on the line l0l0 of Figure 9;

Figure 11 is a cross section on the line ll-H of Figure 10;

Figure 14 is a vertical central section through a pump embodying my invention;

Figure 15 is a cross section on the line [5-45 of Figure 14.

In general, the field of application of the pump embodying my invention is limited to heads up to about feet for cold water, or less if the water is warm, but it is to be noted that the pump may be used for pumping fluids other than water. The pump comprises a rotatable vessel capable of containing a fluid and having a fluid inlet and a fluid outlet. Suitable means for driving the pump may be used. My application Serial No. 561,764, filed September 8th, 1931, and now abandoned, is directed to this subject matter.

Referring to Figure 1, the rotatable vessel comprises the inlet chamber l and the radial arm 2 both of which rotate in the atmosphere about the fixed center or axis 0. The arm has The vessel is filled with fluid, such as water, and provision is made for a constant supply of the water at a pressure such as atmospheric pressure at the center or axis 0. The orifice 3 has the area A in square feet and the coeflicient of discharge K, and the distance from the orifice 3 to the center or axis 0 or the length of the arm is r in feet.

If the vessel is rotated about the center or axis 0 with the angular velocity to, a pressure head is built up owing to centrifugal force equal to K M where V equals (07. Water flows through the 5 orifice 3 under this head with a relative velocity W in feet per second, which is, if losses are neglected, always equal to the peripheral velocity V in feet per second. It is important to remember that the relative velocity W is always equal to the peripheral velocity V, neglecting hydraulic losses and suc- 15 tion lift. In practice, a very close approximation to this may be secured. The quantities of the water discharged from the vessel may be computed from the simple equation for the flow from any orifice 20 (1) Q=KAW or KAV In the modification shown in Figure 1, the

. water would appear to leave with an absolute can easily be computed with 7 representing the weight'of a cubic foot of water as 'yQH *v V 'yKAV (3) s *sso g 550g This is the power supplied to the water. To this should be added the mechanical losses in bearings, windage, and so forth, to get the total power input to the vessel.

The same principles apply to any direction of 50 the discharge of the water from the vessel relative to the tangent to the tip circle or the peripheral velocity vector, as in Figures 2 and 3. As shown in Figure 2, the water may be discharged forwardly in the direction of rotation of the vessel, which comprises the inlet chamber i and the arm 5, which latter is curved forwardly and outwardly and has in its end the discharge orifice B facing radially forwardly to discharge the water at an angle of 0 degrees to the peripheral velocity vector. With this construction the water would appear to leave with an absolute velocity C=2V. As shown in Figure 3, the water may be discharged backwardly relative to the direction of rotation of the vessel, which comprises the inlet chamber 1 and the arm 8, which latter is curved rearwardly and outwardly and has in its end the discharge orifice 9 facing radially backwardly to discharge the Water at an angle of 180 to the peripheral velocity vector. this construction, the water would appear to leave with an absolute velocity C=0.

Each pound of water passing through the pump shown in Figure 2 receives kinetic energy to the amount of and each pound of water passing through the pump shown in Figure 3 receives kinetic energy to the amount of 0.

In each of the above embodiments, the area A is constant and the relative velocity W is always equal to the peripheral velocity V. It is evident, therefore, that the same amount of water is discharged in all of the above cases. In each case the energy given per pound of water is since it is assumed that the water has no energy at the start and the pressures at the inlet and outlet of each vessel are equal.

This leads to a general expression for the work done on the water in each case and for all values of the angle B which is formed by the relative velocity vector W. and the peripheral velocity vector V. The work may be expressed in terms of the equivalent head From the laws of trigonometry, the value of C may be expressed in terms of the two sides of the The angle B may have all values from 0 to 180.

Assume the angle B to be 0, then cos B=+1, and since W=V, the expression for the work done per pound of water becomes This can also be shown by the addition of the vectors V and W, as in Figure 2.

If 3:90, c=vfi and the work done is V2 z. for each pound of water. This is shown in With Figure 1 and also follows from Equation '7, since cos B=0.

If B=180, 0:0, as shown in Figure 3, which also follows from Equation 7, since cos B=-1 and V=W.

In all three above mentioned cases of B=0, or the value of W has always been equal to V and hence the same amount of water has been discharged. The difference is in the power required, omitting losses, to drive the vessel, which varies from per pound of water, if B=0 to 0 when B=180. At first glance, it may be hard to see that the power can be 0 if water is discharged, but this is owing to the fact that the vessel is, in effect, a close combination of a centrifugal pump and a reaction turbine in series. Neglecting losses, all the work done on the water in the centrifugal pump element is regained in the reaction turbine element and the net result is 0 power expenditure. This is true if the pressures at the inlet and outlet to and from the vessel are equal.

A pump may be defined as a machine for increasing the total energy of the fluid passing through it. The energy thus stored in the fluid may be expressed as the sum of the three factors or elements:

(1) Potential or static head or energy (2) Pressure head or energy (3) Velocity head or energy With my invention, this principle, as applied to practice, is used to divide the total energy or head between these factors or elements, such as potential or static head or energy and velocity head or energy, to secure a pump meeting the requirements of the particular problem involved.

For example, one case would be that of raising a fluid to a certain potential or static head and allowing it to flow away with a relatively low velocity. This application is typical of pumps used for drainage or irrigation and might be used also in certain types of lubrication.

For such service, the particular pump, accord ing to my invention, would be so arranged that the angle between the vector representing the relative velocity of discharge from the orifice and the vector representing the peripheral velocity at the center of the orifice is relatively large and preferably 180. In this manner the relative velocity of discharge from the orifice will be nearly equal, including friction losses and suction lift, and opposite to the peripheral velocity of the orifice and the resultant absolute velocity will be relatively small. Figure 4 diagrammatically shows such a pump which embodies the features shown in Figure 3. More particularly, the vessel of Figure 4 comprises the central inlet chamber i0 and the diametrically opposite arms H and this vessel is rotated in a horizontal plane about the vertical fixed center or axis l2. The Vertical inlet pipe l3 extends axially down from the center of the vessel to the body M of the water to be pumped and below the level I5 of this body of water. This pipe, as diagrammatically shown, may rotate with the vessel and it is provided with the check valve I6 at its lower end. The arms have the discharge outlets or orifices I! which open oppositely to each other and provide for the discharge of the water at an angle B of 180, or in a direction opposite to the direction of rotation. Atmospheric pressure acts upon the level of the body of water and the outlets or orifices are open to the atmosphere.

Assuming the vessel, comprising the inlet chamber Ill and the arms II and the inlet pipe l3, to be initially filled with water before being set in rotation by the electric motor 58, which is above and suitably connected to the vessel, it will be seen that when the vessel is set into rotation water will flow out of the discharge outlets or orifices I! at the tips of the arms, thereby creating a partial vacuum at the center of the vessel. Because of this vacuum the atmospheric pressure will force more water into the inlet pipe l3 and up to the vessel, where it is continuously discharged by action of centrifugal force. Since the water is discharged from the arms in a direction opposite to that of rotation of the vessel, relativei and peripheral velocities are nearly equal and opposite and the absolute velocity is very low. This means that the water will fall nearly vertically downwardly, so that it will drop into a suitable container such as the annular container l9 below the vessel and having the discharge outlet 20. Water has thus been elevated through a height equal to the distance between the level l5 of the surface of the body of the water and the plane of rotation of the arms I! or more particularly the discharge outlets or orifices I1, and the pump for doing this may be called a centrifugal re action pump.

An analysis of the vector relations for a typical case is as follows: Assume the arms to rotate with a peripheral velocity at the orifices of 150 feet per second and that the vacuum produced at the junction of the rotatingarms and the vertical pipe is 20 feet. The head producing flow through the orifices may be computed from the well-known formula V 150 H-Tgm351 feet Neglecting losses, "the water would discharge from the orifices with a relative velocity of 150 feet per second produced by the above head of 351 feet, if the pressure at the center were that of the atmosphere and the orifices were open to the atmosphere. Since a vacuum of 20 feet has been assumed at the center, the relative velocity will be that caused by the head 351-20 feet or 331 feet. The velocity due to this head of 331 feet is V=1/64.4 331: 146 feet The absolute velocity will be the difference of 150146=4 feet per second in the direction of rotation. This is a residual loss which can never be eliminated, but which may be made small by using a relatively high tip or peripheral speed V. The mechanical losses in such a pump may be kept low, since the vessel rotates in the atmosphere and nearly all the power applied to the vessel is usefully spent in raising the water. This will make possible unusually high efficiency.

As shown diagrammatically in Figure 5, the same results may be secured by a pump having the discharge outlets or orifices 2! at the ends of the arms of the pump and facing to dishaving at the ends of the arms and secured thereto and rotating therewith the curved deflectors 22 which change the direction of the discharged fluid so that the angle B is 180.

Another case would be that of a pump which '5 is not required to lift against any potential pressure head, but to give this total head largely in the form of kinetic energy. For such purposes the pump, according to my invention, would be arranged to have a definite angle be- 0 tween the peripheral velocity vector at the center of the discharge outlet or orifice and the relative velocity vector at the center of the discharge outlet or orifice. This angle may have any value between 0 and 180, according to the 15 amount of kinetic energy desired. The total kinetic energy in such cases could be readily computed from the formula already given fluid may therefore be varied for any constant value of V from 0 when B is 180 to 8 when B is 90 and to when B 0". The absolute velocity of the fluid leaving the vessel may then be varied from 0 to a maximum of 2V.

This provides a simple and eflicient method of regulating the absolute discharge velocityr.35 to suit the conditions met in the application 'by varying the angle B.

A further example of the application of this invention to practice would be in the case where it is desired to lift a fluid through a certain static head and overcome the losses due to flow and then discharge the fluid at relatively high velocity for the purpose of distributing it over a certain area. The high velocity fluid dis charge can also be varied and controlled by v'ari- 7. ation of the angle B. Such an application may be found highly desirable in spray devices used in air washers and the like and as diagrammatically illustrated in Figures 6, 7 and 8, each may embody the arrangement shown in Figure 155 or some arrangement in which the angle B varies from that shown in Figure 3 to that shown in Figure 2, this angle B controlling both the direction and the absolute velocity C of the discharged fluid. As shown in Figure 6, the fluid-. may be discharged from the rotating vessel through a suitable spray nozzle 23, the arrangement being such that variation of the angle 13 serves to determine both the magnitude of the resultant or absolute velocity of the fiuid and its' distribution over the desired area. As shown in Figure 7, the fluid is discharged from the rotating vessel through the sprinkler head 25, while as shown in Figure 8 fluid is discharged from the rotating vessel and impinges on the impact pins 25, whereby the fluid is broken up into mist.

The ability of the fluid to cover a large area depends on its high absolute velocity, which is more efficiently obtained by my invention than in the usual cases, where a fluid pressure is developed in a pump and this pressure is then used to produce velocity by passing through a spray nozzle or simply an orifice. The value of my invention in this respect can be readily seen fromfi the following example: A centrifugal pump operating at a .shut-ofi or .no delivery produces a pressureof approximately V2 3 c If this pump be used to supply 'fluid toa spray nozzle or orifice the pressure at the point of best efliciency would be in the order of 80% of 2g and the velocity produced by the pressure would be about 90% of V. Now by application of the principles of my invention an absolute velocity of 2V may be obtained. This-may require a head of about were it to be produced by the, ordinary pump. In other words, it would require about a 5-stage pump to produce the same absolute velocity of discharge as a single stage of the type covered by this invention.

By reducing the angle B a lower absolute velocity may be secured. It is also apparent that a combination of several discharge outlets or orifices or nozzles having different angles B may be used to give a more complete covering of an area.

Another application of my invention is illustrated in Figures 9, and 11 and also Figure 12. In most cases it is not possible to reduce the absolute velocity C to 0 and. I therefore provide means for recovering all or at least part of the head represented by this velocity. As illustrated in Figures 9, l0 and 11, the pump comprises the vessel having the central inlet chamber 26 and the outlet arms 21 radiating therefrom and together forming an S-shaped passage, each of these arms being semicircular and having at their ends the discharge outlets or orifices 28 which face radially rearwardly relative to the direction of rotation of the vessel, so that the angle 3:180". This pump is designed to operate primarily as a lift pump and it therefore has provision for discharging the fluid with a relative velocity in a direction inclined downwardly to the plane of rotation of the discharge outlets or orifices in order that the fluid discharged may escape being struck by the arms, which would cause objectionable splashing and consequent waste of power. As shown particularly in Figure 11, the discharge outlets or orifices are positioned in the ends of the arms so that their axes are inclined to accomplish this result. 29 is a casing encircling the vessel and adapted to receive the fluid discharged from this vessel and 38 is a curved deflector orzguide which extends beneath the vessel and flares upwardly and outwardly to a point above the vessel determined by the height to which the fluid will flow under its absolute velocity of discharge.

As illustrated in Figure 12, use is also made of the absolute velocity of discharge of the water to raise the water to a height greater than that of the maximum suction lift, which Iis about 30 feet. As shown, the discharge outlets or orifices 3! at the ends of the arms are preferably not exactly opposite to the direction of rotation of the vessel, so that some'absolute velocity is intentionally left in the discharged water. Also the discharge outlets or orifices are arranged so that they direct the water upwardly and outwardly at an angle 'to the :path of rotation of the vessel, so that this ,water maybe discharged. into a suitable container 32 located at a level rabovethat of the vessel.

It will also be seen that the construction of pump shown'in Figures 9, :10 and 11 using the deflectoror guideprovides for securing a total head higher than that of the maximum suction lift.

Still another application of my invention is illustrated in Figure 13 in which the pump circulates water or some liquid mixture in a container or tank. ;In such a case the static elevation of the water'or liquid mixture may be relatively small and the kinetic energy represented in the absolute velocity of discharge may be used to additionally agitate the water or liquid mixture -:in .the container or tank. The

.degree of agitation and the power required may be varied to suit the-required conditions by varying the angle between the direction of discharge from the discharge .outlets ,or orifices and the plane of rotation .of the discharge outlets or orifices. The construction of pump is similar to that shown in Figures 9, l0 and 11, with the exception'that the'guide or deflector is omitted and the water or liquid mixture is directed from the discharge outlets or orifices 33 directly downwardly into the water or liquid mixture in the container or tank, the vvessel including the discharge outlets or orifices being located above the surface of this :water ,orliquid mixture.

Figures 14 and more :nearly illustrate an actual construction of pump embodying my invention in which the pump vessel comprises the central inlet chamber 34 and the diametrically oppositeoutlet arms 35 which together form an S-shaped passage and each of which aresemicircularand are curved rearwardly or in a direction opposite to that of rotation of the vessel, as indicated by the arrows inFigure 15. The outer ends of these arms are each provided with the plug 36 having the discharge or outlet orifice 31 therein, which is sovarranged that upon rotation of the vessel the water is discharged in a direction exactly opposite .to-thedirection of rotation of the discharge outlet or orifice and the angle B=180. Furthermore, these discharge outlets or orifices preferably have their axes inclined downwardly and outwardly in the same manner as shown in Figure 11. The pump vessel has the central depending flange 38 which is concentric with the axis of rotation of the vessel and through which the vessel is journalled upon the upwardly extending cylindrical flange 38' of itheibase 39. This base, as shown, forms a container for the water and has the discharge or outlet 40 which is provided'with the weir 4| controlling the height of the water in the base, so that it will clear the oulet arms 35 and also seal the joint between the parts 38 and 38, it being apparent that suitable bearings may be employed between these'parts. As shown in this construction, the central inlet pipe 42 does not rotate with the pump vessel, but is formed by the cylindrical flange '38 and the depending pipe section .43 of the base and the pipe section 44, which latter is secured to and depends from the former. The lowerend of this pipe is provided with the check valve 45. The top of the vessel is provided with the depending central guide portion 46 having its face preferablyrounded and merging into the tops of the outlet arms, and this top is also provided with the central upwardly extending projection 41 which has the polygonal socket 48 for receiving the correspondingly shaped lower end of the rotor shaft 49 of the electric motor 50. The upwardly extending projection projects through the top 5! for the container formed by the base 39 and this top supports the electric motor. The interior of this container is open to the atmosphere, air being permitted to enter through the discharge or outlet 40 or through other suitable openings, such as the clearance space between the upwardly extending projection and the upwardly extending projection 41 and the top 5!, and since the body of the water being pumped has its surface subjected to atmospheric pressure, the operation of the pump is as previously described.

In the application of the principles of my invention to practice, certain proportions of the elements are of great importance. In order to have satisfactory operation it is necessary to proportion the area of the discharge outlet or orifice according to the area of the central inlet chamber or the area of the central inlet or supply pipe, Whichever is the smaller. It is also necessary to proportion these areas according to peripheral speed of the vessel at the center of the discharge outlet or orifice. The maximum area at the discharge outlet or orifice or the maximum aggregate area at the discharge outlets or orifices, if more than one is used, should not exceed the value given by the formula where A2 is the area of the discharge outlet or orifice or the aggregate areas of the discharge outlets or orifices, V2 is the peripheral velocity of the vessel measured at the center of the discharge outlet or orifice and A5 is the cross sec- 'tional area of the inlet chamber or inlet pipe,

may be expressed by the following equation:

1200 D1(max)=R. P. M.

where D1 is the diameter in-feet of the inlet chamber. Smaller values of D1 will be found to be more eflicient, but the value should not exceed that given by the above formula.

All of the pumps embodying my invention and including those illustrated embody the above proportions.

From the above description, it will be seen that a pump embodying my invention has its elements proportioned in accordance with the above mentioned formulae. It will also be seen that according to my invention the total energy given by a fluid pump to each pound of water passing through the pump may be variably divided, as desired, into kinetic and potential energy by varying the plane of elevation of the rotor and thereby varying the head through which the water is raised, by varying the peiipheral velocity of the discharge outlet or oriflce, and by varying the angle between the relative velocity and the peripheral velocity vectors. It will further be seen that my pump may be designed to secure a total head higher than that of the maximum suction lift.

My copending application Serial No. 678,962 filed July 3rd, 1933, is a continuation in part of this application and claims the generic subject matter.

What I claim as my invention is:

A pump, comprising a rotatable vessel having a fluid inlet and a fluid outlet with the latter positioned to discharge the fluid directly into a gaseous medium under pressure produced by the rotation of the vessel in a substantially radial direction, and a curved deflector secured to and rotatable with said vessel for changing the direction of the fluid discharged from said outlet so that it will be substantially opposite to the peripheral speed vector at the discharge from said deflector.

ALLEN F. SHERZER.

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