FR2544890A1 - Measuring and metering device for fluids - Google Patents

Abstract

Measuring and metering device for fluids, making it possible to meter an additive fluid into a main fluid, comprising a cylindrical body 1 pierced with inlet and outlet apertures 4, 5 for the main fluid, a rotor 8 housed in the body 1 and off-centre with respect to the latter; the rotor 8 comprises at least one radial housing in which a piston 16 is mounted so as to slide and is held elastically bearing against the inner wall of the body 1, the radial housing of the piston 16 communicating with a conduit formed axially in the rotor 8 and which is provided, at its ends, with inlet 19 and outlet 21 valves, allowing a quantity of additive to be let in and out, the successive uptake and outflow cycles brought about by the piston 16 at each revolution of the rotor 8 introducing into the latter a quantity of additive which is next driven back to the output in the main fluid. This simple and inexpensive measuring-metering device injects the additive into the flow of the main fluid in strict proportion.

Description

 The subject of your present invention is a device for measuring and measuring fluids, which can be used for example for dosing food in industrial poultry, pig, rabbit, irrigation, for all liquid dosages carried out continuously in the industry, etc ...

 To ensure the metering of an additive fluid to a main fluid, for example a main water stream, injection pumps are used which can be produced in several ways.

 Thus, there are known venturi systems operating by vacuum and bladder and nozzle systems. These devices have the disadvantage of not injecting the additive in a manner strictly proportional to the flow rate of the main fluid. In addition, in the case of the system bladder and nozzle #, it must go through an intermediate tank, which complicates the device and increases its cost.

 There are also known metering measuring devices in which the metering is carried out by an alternating water motor, controlling a piston which regulates the injection of additive. Such an alternative water motor device is strictly proportional to the flow rate, but, because of its relative complexity, its cost price is high.

 The object of the invention is to provide a device for measuring and dosing fluids ensuring an additive flow rate strictly proportional to the main fluid flow rate and which, moreover, is considerably simplified in relation to known devices so as to reduce its manufacturing cost while guaranteeing excellent operational reliability.

 The device for measuring and dosing fluids targeted by the invention comprises a cylindrical body pierced with inlet and outlet openings of a main fluid stream, a rotor housed in the body coaxial thereto, and means for injecting and metering through the rotor an additive fluid coming to mix with the main fluid in the vicinity of the outlet opening, the rotor being driven in rotation by the main fluid.

 According to the invention, the rotor comprises # at least one radial element inside which is slidably mounted a piston bearing against the inner wall of the body, and an elastic return member of the piston against the wall of the body and disposed inside the radial housing, the internal section of the body and the section of the rotor being such that the distance between the rotor and the wall of the body at the location of the piston varies during rotation of the rotor in order to cause displacements alternating piston, and a fluid supply conduit, provided with inlet and outlet valves and communicating with the radial housing and formed in the rotor.

 If the internal section of the body and the section of the rotor are circular, the rotor is eccentric with respect to the axis of the circular cylindrical body, so as to cause alternating displacements of the piston during the revolutions of the rotor.

 The piston therefore exerts at each revolution a suction and a delivery of additive fluids, the inlet valve being arranged to allow the entry of additives during the suction phase while the outlet valve is fen: é, and vice versa. during the delivery phase of the additive by the piston.

 The rotary rotor is driven by radial paddles slidably mounted in radial slots of the rotor and constantly held in abutment against the inner wall of the body by elastic elements housed in the slots. These paddles therefore go back and forth in radial directions during the revolution of the rotor which thus appears as a kind of impeller.

 Such a metering-dosing device can be produced with a reduced number of parts, this simplicity compared to the known water-reciprocating engine, making it possible to considerably reduce its cost price compared to this engine.

 Other features and advantages of the invention will become apparent during the description which follows, given with reference to the accompanying drawings which illustrate by way of nonlimiting examples two embodiments.

 Fig. 1 is an exploded perspective view of a first embodiment of the fluid metering device according to the invention.

 Fig. 2 is a cross-sectional view along 2 -; o of FIG. 3.

 Fig. 3 is a view in axial longitudinal section along 3 - 3 of FIG. 2.

 Fig. 4 is a cross-sectional view of a second embodiment of the measuring device according to the invention.

 Fig. 5 is an axial section view of the device of FIG. 4.

The device for measuring and dosing fluids illustrated in FIGS. 1 to 3 is intended to inject a dose of additive fluid to a main fluid stream, for example a stream of water in an industrial farm
poultry for feeding or ad
ditlon of cutting oil to batten on a: nachine-or-
til or a liquid fertilizer with irrigation water.

This device comprises a cylindrical body 1 provided at its two ends with flanges 2,3 in which are respectively formed an inlet opening 4 and an outlet opening 5. End pieces 6 and 7 are respectively connected to the openings 4 and 5 which are conver, aDlement offset angularly, the flanges 2,3 being fixed to the body 1 by any suitable means known per se, not shown. The device also comprises a cylindrical rotor 8 of circular section mounted in the body 1 eccentrically relative to the axis of the latter. For this purpose, the rotor 8 comprises on sDs two end faces of the axial bearings 9, 11 which are engaged in es corresponding openings 12,13 arranged in the flanges 2,3.
Under these conditions, the rotor 8 is practically in contact with the inner wall of the body 1 on one side, and the spacings between the surface of the rotor 8 and the inner wall 1a of the body 1 gradually increase on either side of this contact generator (Fig. 2).

 The rotor 8 is equipped with several radial paddles 13a, 13b, 13c, 13d, which are therefore four in this example, angularly spaced by 900. The paddles 13a - 13d are slidably engaged in corresponding radial slots 14a, 14b , 14c, 14d, of the rotor 8 inside which are placed elastic elements, not shown to simplify the drawing, which constantly keep the paddles 13a-13d in abutment against the inner wall 1a of the body 1 during the revolutions of the rotor 8 The aforementioned elastic elements may for example be helical springs or elastically arched blades, bearing on the bottom of the radial slots 14a-14d.

 According to an essential characteristic of the invention, the rotor 8 comprises a radial housing 15 (Fig. 2) inside which is slidably mounted a piston 16 bearing against the inner wall la of the body 1, the head of this piston being suitably arranged to be able to slide on this wall. An elastic member 10, constituted in this example by a helical spring, is placed in the housing 15 bearing on its bottom and constantly urges the piston 16 against the inner wall la, so as to keep it constantly in abutment against it.

 Furthermore, according to a complementary feature of the invention, a conduit 17 for supplying additive fluid is formed axially in the rotor 8 from one end to the other thereof, and this conduit 17 communicates by a radial bore. 18 with the housing 15 of the piston 16. The conduit 17 is completed at its ends by an inlet valve 19 and an outlet valve 21. The valve 19 comprises an endpiece fixed to the flange 2 coaxially with the rotor 8 and with the conduit 17, a ball 20 placed in this end piece and a spring 22 normally holding the ball 20 applied to its seat by closing off an additive fluid inlet pipe 23. The outlet valve 21 comprises an end piece fixed in the flange 3 coaxially with the conduit 17, for example by screwing like the end of the valve 19, a ball 24 and a spring 25 normally holding the ball 24 applied to its seat by closing a pipe 26 for output of the additive fluid. In addition, the outlet valve 21 communicates with the nozzle 7 for the outlet of the main fluid by a connector 27. The valve 19 is arranged so as to open by detachment of the ball 20 from its seat under the effect of a suction in the duct 17, while conversely this suction reinforces the application of the ball 24 on its seat and therefore the closing of the outlet valve 21. Conversely, when there is an overpressure in the duct 17, the ball 20 closes the inlet pipe 23, while the ball 24 is detached from its seat 11 against the opposing bias of the spring 25, which allows the fluid introduced into the conduit 17 to pass through the connector 27 in the outlet nozzle 7 of the main fluid.

The implementation of this metering device is as follows
The main fluid, for example water, enters through the nozzle 6 and the opening 4, enters the intermediate volume between the rotor 8 and the body 1, and drives the rotor 8 in rotation by the paddles 13a-13d , then exits through the end piece 7. During each revolution of the rotor 8, the pallets 13a-13d move back and forth by sliding in the slots 14a-14d while remaining in contact with the inner wall la, and likewise the piston 16 performs an alternative movement between its position shown in Fig. 2, in which it is almost entirely outside the housing 15, and a diametrically opposite position in which it is almost completely retracted into the housing 15.

These radial displacements of the piston 16, equal to those of the vanes 13a-13d, are strictly synchronous with the revolutions of the rotor 8, that is to say proportional to the flow rate of the main fluid passing through the metering device.

 The piston 16 slides out of its housing 15, it produces by the hole 18 a suction in the conduit 17, which opens the inlet valve 19 and closes the outlet valve 21 as explained above.

The valve 19 being connected to a reservoir of additive fluid not shown, a dose of additive is therefore sucked into the conduit 17. Then, when the piston 16 descends inside the housing 15, that is to say during a half-to.ur made from its position in Fig. 2 to a position in which it is diametrically opposite to this starting position, a discharge overpressure is created by the conduit 17.

This overpressure triggers the closing of the inlet valve 19 and opens the outlet valve 21, the ball 24 of which moves away from its seat, so that during this delivery phase, the dose of additive fluid contained in the rotor 8 is expelled by the connector 27 to the outlet nozzle 7, where it mixes with the main fluid.

 This process is repeated with each revolution of the rotor 8.

 The metering device according to the invention is produced with a minimum number of parts, which simplifies its manufacture and considerably reduces its cost price compared to the prior measuring device with reciprocating water engine. In addition, it can operate at a lower water pressure and at a lower flow rate than this prior device, because the friction there is much lower. This constitutes an important advantage, because the flow rates of feed liquids are often low in industrial poultry farms, for example of chickens whereas they must be high in cleaning applications for example. The device must be able to operate with large differences between small and large flow.

 In section '7: ## e o realization -.u -esurnlr- doser illustrated Tabs 4 and 5, the body 23 has an inner section 28a oval or substantially elliptical, while the section of the rotor 29 is circular. The rotor 29 is mounted in the body 28 coaxially with the latter, so as to reserve on either side of the rotor 29 two intermediate volumes with crescent-shaped section.

 The rotor 29 has at least one pair of radial housings 31, 32 diametrically o1i #? Dare visible in Figure 4, and in Figure 5 Ce, housings 31, 32 open into an axial duct 33 passing through the rotor 29 right through , the pistons 34, 35 being slidably mounted in these housings. Helical springs 36 disposed in the housings 31 exert an elastic stress on the pistons 34 which keeps them constantly applied against the interior wall 28a.

 The rotor 29 is provided on its opposite faces with bearings 37, 38 coaxial with the duct 33 and engaged in flanges 39, 41, the flange 39 being provided with a nozzle 42 for main fluid inlet, while the flange 41 comprises a nozzle 43 for the outlet of the main fluid.

 On the other hand, a light 44 is formed in the wall of the inlet bearing 37 over a suitable angular sector, so as to communicate during a fraction of each revolution of the rotor 29, with a pipe 45 for the entry of additive fluid. A, l second light 46, partially visible in Figure 5, is arranged in the output bearing 38 on an angular sector equal to that of the input light 44, so as to communicate during the corresponding fraction r evolution of the rotor 29 , with a passage 47 pierced in the flange 41. The passage 47 in turn communicates with the opening 50 Se leaving the main fluid, formed in the flange 41.

 The lights 44 and 46 communicate of course permanently with the axial duct 33, and are suitably angularly offset so that when one is closed, the other is opened by communication with the corresponding pipe 45 or 47. These openings and closings lights 44, 46 replacing the inlet and outlet valves of the previous embodiment are obviously synchronized with the suction and discharge phases created in the duct 33 by the alternating movements of the pistons 34 and 35.

 Radial vanes 48, six in number in this embodiment, three on each side of the diametral plane defined by the pistons 34, 35, are slidably mounted in slots of the rotor 28 in which are placed organs e # elastic formed by cambered metal blades 51, which keep the pallets 48 in sliding contact with the inner wall 28a.

The flanges 39, 41 are fixed to the body 28 by any suitable means not shown, and in a leaktight manner by means of seals 52. Holes 53, 54 formed in the interior faces of the flanges 39, 41 respectively, establish communication between on the one hand the inlet opening 54 of the end piece 42 and
the intermediate volume between the rotor 29 and the body
28, and on the other hand between this intermediate volume and
outlet opening 48.

In this embodiment, the aspira phase
tion of the additive fluid is ensured by sliding
simultaneous pistons 34, 35 outwards
of their housings, the light 44 then being open,
and in addition, the delivery of the dose of additive sucked into the duct 33 is created by the return of the pistons 34, 35 in their housings, the light 44 then being closed while the light 46 is in communication with the passage 47. A each delivery, the dose of additive aspirated is therefore expelled through the passage 47 in the opening 48 or it mixes with the main liquid.

 This embodiment has the advantage over the previous one of balancing all the reactions developed in the metering device by virtue of the diametrically opposite arrangement of the pistons 34, 35.

This makes it possible to minimize the efforts on the bearings 37, 38 and, by beneficial effect on their performance, increases the limits of use and the operating precision of the device.

 The invention is not limited to the embodiments described and may include variant embodiments. Thus, a body of conchoidal type with three lobes can be produced; in this case, there will be three sets of pistons, spaced at 1200. The fundamental principle being that all the pistons operate in synchronism since they communicate with a common manifold 33.

The body can be a conchoid with n lobes, 3600 with pistons spaced by n .n
On the other hand, in the case where the internal part of the stator section is constituted by an odd number of conchoidal cells (at least one), the return spring (s) of the piston (s) ) can (can) advantageously be replaced) by a rod with a diameter smaller than that of the piston. The rod associated with each piston then extends the latter while crossing the rotor, so as to always be in contact with the internal surface of the stator, the rotation of the rotor automatically causing an alternating movement of the piston.

Claims (6)

 1 - Device for measuring and measuring fluids, in particular for  - industrial dosages of liquid additives to a main liquid,  - the dosage of liquid fertilizer in watering,  - the supply of industrial farms, comprising a cylindrical body (1, 28), - pierced with openings (4, 5; 54, 50) for inlet and outlet of a main fluid stream, a rotor (8, 29) housed in the body and means for injecting and metering through the rotor (8, 29) an additive fluid mixing with the main fluid in the vicinity of the outlet opening (5, 48), the rotor (8, 29) being driven in rotation by the main fluid, characterized in that the rotor (8, 29) comprises at least one radial housing (15, 31) inside which a piston (16) slides , 34, 35) resting against the inner wall (la, 28a) of the body, and an elastic return member (17, 31) of the piston (16; 34, 35) against the wall of the body (1, 28) is disposed inside the radial housing (15, 31), the internal section of the body (1, 28) and the section of the rotor (8, 29) being such that the distance between the rotor and the wall of the body at location of the piston (16; 34, 35) varies during rotation ation of the rotor in order to cause reciprocating displacements of the piston, and a conduit (17, 33) for supplying additive fluid, provided with inlet and outlet valves, is formed in the rotor (8, 29) and communicates with the radial housing (15, 31).  2 - Device according to claim 1, characterized in that the inlet valve (19) is arranged to open and allow the introduction of additive fluid into the conduit (17) when the piston (16) slides towards the outside of its housing (15) and therefore exerts suction in the duct (1-), while zirltivement the outlet valve (21) is arranged to close, and vice versa when the piston {16) is inserted into its radial housing (45) during part of each revolution of the rotor (8) by exerting a compression, during which the dose of aspirated fluid is then expelled and mixed with the main fluid at the outlet (7) of the body (1).  3 - Device according to claim 2, characterized in that the valves (19, 21) are of the non-return ball type (21, 24) biased iar a return spring (22, 25) on its seat, the conduit ( 33) being formed axially in the rotor (8), which is eccentric relative to the cylindrical body (1).  4 - Device according to claim 3, characterized in that the body (1, 28) has a circular outline, or oval, or conchoidal.  b - uisPositi- 'according to claim 1, characterized in that the body (28) having an oval or conchoidal inner section, while the rotor section (29) is circular, the rotor (29) has at least one pair of radial housings (31) diametrically oi ?? dare and which contain two pistons (34, 35) slidably mounted in these housings, in which are placed springs (36) for returning the pistons (34, 35) against the wall ( 28a) of the body, and lights (44, 45) are arranged in bearings (37, 38) of the ends of the rotor (29), in communication on the one hand with an inlet channel (45) of the additive fluid and on the other hand with a passage (47) for connection with the outlet opening (48) of the mixture of the main fluid and the additive, these openings (44,45) extending over polar sectors suitably offset so that the inlet lumen (44) communicates with the axial duct (33) .of the rotor (29) during the suction phase by two pistons (34, 35) while that the exit light (46) is then closed and does not communicate with the exit passage, and vice versa during the delivery phase of the dose of additive fluid introduced.  6 - Device according to one of claims 1 to 4, characterized in that the body has a shape of the conchoidal genus has n lobes, the rotor comprising radial housings separated by equal angular intervals, at 3600 in each of which is slidably mounted a  n piston kept constantly pressed against the inner wall of the body by an elastic return member.  7 - Device according to claim 1, characterized in that, in the case where the inner part of the rotor section is constituted by an odd number of concholdal cells, the (or the) piston (s) is extended (s) through the rotor by a rod whose end opposite the piston is always kept in contact with the internal surface of the stator, the rotation of the rotor automatically causing a reciprocating movement of the piston and the rod having a diameter smaller than that of the piston.