EP0483298A1

EP0483298A1 - Self-priming pumping method and device

Info

Publication number: EP0483298A1
Application number: EP91905838A
Authority: EP
Inventors: Claude Pierre Louis Girardet
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-23
Filing date: 1991-02-25
Publication date: 1992-05-06
Also published as: FR2658870B1; FR2658870A1; WO1991013258A1

Abstract

Le dispositif de pompage à amorçage automatique d'un fluide porteur à partir d'une première enceinte vers une seconde enceinte (5), comprenant une pompe à auto-amorçage (effet déprimogène) comportant une vis sans fin (1) solidaire d'une âme (30) pour former des filets délimitant entre eux une série de volumes successifs formant une chambre de pompage (31) dont la capacité augmente de l'entrée (32) de la pompe vers sa sortie (33), est caractérisé en ce que sa sortie (33) débouche dans la deuxième enceinte (5), de manière à être immergée dans le fluide porteur qui y est contenu pour refouler, par le même orifice (33), à l'amorçage, le porteur dit majoritaire de la seconde enceinte (5) plus rapidement que la pompe ne l'introduit à l'intérieur de la vis (1).The pumping device with automatic priming of a carrier fluid from a first enclosure to a second enclosure (5), comprising a self-priming pump (negative pressure effect) comprising an endless screw (1) secured to a core (30) to form threads delimiting between them a series of successive volumes forming a pumping chamber (31) whose capacity increases from the inlet (32) of the pump to its outlet (33), is characterized in that its outlet (33) opens into the second enclosure (5), so as to be immersed in the carrier fluid which is contained therein in order to discharge, through the same orifice (33), on priming, the so-called majority carrier of the second enclosure (5) faster than the pump introduces it inside the screw (1).

Description

SELF-PRIMING PUMP DEVICE AND METHOD

The present invention relates to an automatic self-priming pump. The term "self-priming"

means that, to convey a fluid (gaseous or liquid ...) from point A to point B, a vacuum or suction is created so that the starting point (A) can convey these liquid or gaseous fluids , with a density greater than the density of the air, over gradients of several meters to the highest point (B).

The main self-priming pumps

existing are of the type known as gears, valves, membranes, peristals or of a more recent type consisting of a pump which uses the effect of

deformation of a carrier liquid, creating a depression (see US Patents 4,562,605).

The pumps identified as follows:

- DE-A-2004166 (PLESSEY)

- FR-A-719967 (MERCIER)

- BE-A-393560 (BAERT)

- GB-A-26766/1911 (HANSEN)

- SU-A-177284 (GOLUBYEV)

- US-A-2030560 (ADAMS)

for some of them have either:

- a conical screw

- a variable pitch screw

- a turbine

but are not self-priming. The type of self-priming non-automatic eccentric screw pump (GB-A-1425997 patent) works only when the pump body is in a strictly horizontal position. Indeed, the horizontality with respect to the axis of rotation of the mobile element of the system (screw, turbine ...) is required to generate the centrifugation necessary for the proper functioning of the system and requires a priming flow or carrier of density substantially homogeneous to the main flow, called "through" that is to say using an opposite inlet and outlet, and positioned on the body of the pumping system.

The invention makes it possible, by a different method, to create, with the aid of any carrier, suction or depression by the depressogenic effect. This process consists in creating a difference in flow rate between the carrier whose quantity of introduction into the pump is less than the quantity of extraction and this, by a single submerged orifice (see fig. 1, 2, 3).

It should indeed be noted that, in the phase

"priming", the carrier flow which will create the vacuum necessary for the "pumping of the fluid to be conveyed" (or minority fluid) function, enters and leaves through the same orifice 33; note the spectrum of the priming fluid in the form of the letter V mark 8 fig. 1.

This device has partial reversibility without any modification, it then becomes a pumping process with non-automatic priming. This device can therefore convey liquid or gaseous fluids by having a constant charge on the orifice 33 then called INPUT.

The OUTPUT located in reference 11; the pos i t i on of the optional non-return valve, is an external function and not at all necessary for the good

operation of the device.

In general, a pump is intended to pump a carrier which is located in a first enclosure, towards a second enclosure. This flow is called "minority fluid".

The method can be obtained by the fact that the pumping chamber increases while moving in the direction of the carrier to be pumped. The term "carrier" designates a liquid, gaseous or pulverulent fluid.

In the case of the invention, this variation in volume of the chamber means that part of the carrier, filling the second enclosure, is sucked in opposite direction to the direction of the minority carrier.

The sum minority flow and majority flow constitutes the resulting carrier.

The majority carrier comes from the second enclosure 5 consisting of a tank. This process

works when the pump output is

immersed in the content in the second enclosure.

Due to the variation of the pumping chamber. part of the carrier, contained in the second enclosure, is sucked into the pumping chamber, in a direction opposite to that of the minority carrier, up to the level of the pumping chamber of the minority carrier coming from the first enclosure, so that the minority carrier is mixed with the carrier

majority.

In the case where the carrier of the second enclosure is constituted by a liquid, the carrier, comprised between the pumping chamber and the first enclosure, consists of gas, while the resulting carrier consists of a mixture of liquid and gas bubbles.

It follows that, very quickly, this gaseous part is expelled into the second enclosure, creating, in the inlet pump, a vacuum which sucks the liquid product from the first enclosure.

From this moment, the minority holder is liquid.

The pump also operates when the second enclosure is filled with gas and the first enclosure is filled with a gas to be pumped or a liquid to be pumped. This variation of the room can be obtained:

a) - in the variable pitch worm whose central core can be linear or conical,

b) - in a constant pitch worm whose

central part can be linear or conical. The parameters for screw pitch variation. of taper (linear, concave, convex, stepped or indeterminate) influence the performance of the pump.

This operating principle is that the inlet volume of the pumping chamber of the carrier product is less than the outlet volume of the pumping chamber. Whatever the diameter, the length, the pitch of the screw, the angle of the cone, these parameters

only intervene to obtain different yields (difference in suction or vacuum value, difference in flow rate).

The operating principle remains whether the pitch of the screw is on the right or on the left.

The principle of operation by effect

depression is based on the fact that the rotation of the screw, from a certain speed pushes back the majority carrier more quickly than it

introduced it inside the screw by the same

orifice, thus creates a vacuum (this minimum speed of rotation will be called "priming speed"), thus allowing the suction of a minority carrier product.

This priming speed decreases as a function of the difference between the inside diameter of the pumping chamber and the outside diameter of the movable part, or screw.

This speed is minimum when there is mechanical contact between the two aforementioned values (example: vane pump). Priming speed reached, flow rate

of the minority holder increases following a

function, related to the increase in the speed of rotation of the screw. This pump therefore works with a primary carrier product.

The part, causing the rotation of the screw, can be an electric motor, a hydraulic turbine, a pneumatic turbine or any other system causing the rotation of an axis.

Other features and benefits of

the invention will be better understood on reading the. description and examples of the following embodiments, made with reference to the accompanying drawings in which:

- Fig. 1 is a vertical section of the pump part shown diagrammatically to explain its operation,

- fig. 2 and 3 are vertical sections

representing practical achievements of the pump. non-limiting, given simply as

examples,

- fig. 4 is a vertical section taken from FIG. 1 of an example of driving the screw 1, using an electric motor,

- fig. 5 and 5a represent, so

schematic, the magnetic drive integral with the motor drive axis.

- fig. 7 shows a schematic vertical section of a pump and a driving part. According to the invention, the pump comprises, according to a first embodiment (fig. 1 and 2), an endless screw 1 whose core 30 is conical and the outside diameter of the threads constant.

The part of the screw close to the inlet of the pump opening into the first enclosure is called the front part 32 of the screw 1 and the part i e

opening into the second enclosure 5 is called the rear part 33 of the screw 1.

The volume in the depth of a thread increases when one moves from the inlet of the pump towards its outlet in the second enclosure 5. The screw 1 is mounted in a cylindrical chamber 31, of constant diameter.

According to a second exemplary embodiment (FIG. 3), the core 30 of the screw 1 has a constant diameter all along the screw 1 and the outside diameter of the threads is conical. The small diameter of the cone is located at the entry of the minority carrier and the large diameter at the exit of the second enclosure 5.

The chamber 31 is then conical, with the same conicity as the screw 1.

The front part 32 of the screw 1 is connected to a base of the magnetic drive integral with the screw 1. The connection between the driving axis and the driven axis is mechanical with, for example, etanσhéité by rotary joint.

A stop spacer 3 made of electrically conductive material or not, is located between this base and a stopper 7.

A stop 7 and an electrode 6 allow information to be taken for measuring the resistivity of the resulting bath, with a view to checking it.

For the reference electrode 6. the material used must be electrically conductive. For the stop marker 7, the material used must be electrically conductive, not magnetic during magnetic coupling between the driving part and the driven part.

The arrow 8 indicates the direction of aspiration of the majority carrier and its delivery into the tank 5 through the same orifice, while the arrow 9 indicates the direction of the minority carrier product coming from the first enclosure.

The keeper 10 represents the result, after priming, of the majority carrier liquid + minority carrier liquid.

A non-return valve 11 is fixed on the inlet of the pump. The pump is fixed either by axis, threaded nut, clip or any other means

schematically by reference 12.

The screw 1 being rotated in the direction of the pitch (right or left) attracts the carrier liquid 8 against the direction (depression effect), causing resistance to the introduction of the carrier liquid. Next the

diagram, the carrier liquid leaves at 10 with a volume greater than the inlet volume creating a depression and we find, at this point, a mixture of the carrier liquid 8 and the minority carrier liquid 9.

The driving part consists of the stop 7 serving to take resistivity information in the bath.

Against this stop, a stop spacer 13 made of electrically conductive material or not, limiting the axial force on the driving axis, whether it comes from an electric motor 16 or from any other axis

drive. According to an exemplary embodiment, the drive means 14 consist of a base of the magnetic drive secured to the axis

drive (axis of an electric motor or any other drive axis). We notice the mounting of a magnetic short circuit 20 (fig. 6).

This electric motor 16 is placed in a

protection 15 and is powered by lines

electrical 17 and 18.

In fig. 5 and 5a, there are the elements bearing the following references:

The screw in conductive material or not

of electricity 1 with its solidarity base 2 of

the magnetic drive rests on a stop spacer 3 provided with rare earth, samarium, cobalt or neodymium, iron or boron 19 magnetic parts.

The stop spacer of conductive or non-conductive material 13 may or may not be put in place and housed in the magnetic drive base 14 secured to the drive shaft of the motor 16 as well as the parts rare earth, samarium, cobalt or neodymium, iron or boron magnets 19 placed on a magnetic short circuit 20.

This is an example magnetic coupling for the following characteristics:

- reference 19: samarium cobalt magnetic material 210 kj / m3

- dimensions:. diameter: 6 mm,

. thickness: 4 or 5 mm.

The characteristics of drive torques for the example given are as follows:

- rotary torque ............................................... 0.35 Newton

- axial torque ............................................... ......... 0.6 Newton

- distance between the two magnetic pieces

.................................................. .................. 2.5 mm

We notice, in fig. 6 and 6a,

representing in more detail the magnetic coupling, that the use of rare earth elements allows us to avoid a magnetic short circuit causing only a very low loss of torque

rotary, but greatly simplifying the mechanical production of the screw.

Any coupling with different characteristics can be achieved by increasing the number of magnetic parts. The mounting radius of these magnetic parts is dimensioned so as to obtain a higher torque for pumps of larger dimensions. Rare earth magnets have been used in such a way as to reduce the mechanical dimensions for a given transmission torque and, by

therefore reduce the energy required

the training of the whole.

Fig. 7 shows all the references cited above.

The magnetic drive makes it possible to have an intrinsic seal, as well as motor protection in the event of blockage of the pump part.

The different positions of the pump in no way modify its operation.

During operation, the majority carrier raises the threads of the screw around its core against the current of the resulting carrier.

Of course, various modifications can be made by those skilled in the art to the pumps which have just been described only by way of nonlimiting examples, without departing from the scope of the invention.

In illustration fig. 7 (scale not respected) a pump with an internal diameter of pumping chamber of 15 mm is equipped with a conical screw with an overall length of 68 mm (including the base of the support

magnetic).

The conicity is over a length of 58 mm defined by two opposite diameters varying from 10 mm (on the side of the magnetic support base) to 5 mm.

The minimum priming speed in this example. is of the order of 6000 revolutions / minute. The flow rate is proportional to the speed of rotation of the mobile element.

In the same illustration, a speed of the order of 12,000 revolutions / minute generates an approximate flow of 30 liters / hour.

Claims

CLAIMS:

1 - Pumping device with automatic priming of a carrier fluid from a first enclosure to a second enclosure, comprising a self-priming pump (depressogenic effect) comprising an endless screw (1) integral with a core ( 30) to form threads delimiting between them a series of successive volumes forming a pumping chamber (31) whose capacity increases from the inlet (32) of the pump towards its outlet (33),

characterized in that the pump is self-priming and in that its outlet (33) opens into the second enclosure (5), so as to be immersed in the carrier fluid contained therein for discharging, through the same orifice (33 ), upon priming, the so-called majority carrier of the second enclosure (5) faster than the pump introduces it inside the

screw (1).

2 - Device according to claim 1,

characterized in that the described pump retains all its characteristics in optimum value whatever its mounting position.

3 - Device according to claim 1 and 2, characterized in that the pump comprises:

- a moving part, made of carbon (screws)

- a magnetic drive member (14, 19. 20)

including rare earth coupling parts, of the samarium, cobalt or neodymium type of iron or boron. 4 - Device according to claim 1 and 2.

characterized in that the core (30) is conical and the external diameter of the threads is constant, so that the volume occupies, between two threads, increases as one moves from the front part (32) of the pump towards its rear part (33).

5 - Device according to claim 1 and 2, characterized in that the core (30) has a diameter

constant and the outside diameter of the threads is conical, so that the volume occupied between two threads increases when moving from the front part (32) of the pump to its rear part (33).

6 - Device according to one of the preceding claims, characterized in that the pitch of the f i l ets is constant.

7 - Device according to one of claims 1, 2, 3, 4 or 5, characterized in that the pitch of the threads is variable.

8 - A method of pumping a fluid, called carrier, from a first enclosure to a second enclosure, using an automatic priming pump, according to one of claims 1 to 7.

characterized in that it consists:

- plan to fill the second enclosure

with a so-called majority fluid and at y

immerse the pump outlet. - to ensure the priming of the pump by starting the latter at a speed sufficient to create a vacuum in the pumping chamber and to discharge from said chamber the majority fluid more quickly than it is sucked,

- once priming has been carried out, pumping is carried out in the conventional manner by aspiration of the carrier fluid.

9 - Process according to claim 8, characterized in that it consists in creating depression by

aspiration of the majority fluid in the pumping chamber, simultaneously and in the opposite direction to

the suction of the carrier fluid, until the majority fluid is discharged into the second enclosure at the end of priming (depression effect).

10 - A method according to claim 9, characterized in that, after priming, the variation of the pumping rate is ensured by simple variation of the speed of rotation of the pump.