Patent Application
20160325244
The invention relates to a static mixer for homogenizing a mixture of at least two liquids, in particular after injection of an auxiliary liquid into a main liquid.
Injection by means of hydraulic dosing pumps of a mixture of water and an auxiliary liquid product in two separate phases is known, in particular from FR 2 967 218 in the name of the applicant company. The auxiliary liquid, in the case of use in an agricultural environment, can be constituted by nutrients in solution, or by veterinary drugs. It is important for the mixing of the main liquid and the auxiliary liquid to be as homogenous as possible. The same requirement may apply in other applications, since the dosing pumps in question can be used in industry, in hospitals, or in other fields which also make it necessary to obtain a homogenous liquid mixture, according to the dose prescribed for the auxiliary liquid.
The objective of the invention is thus to provide a static mixer which is simple and economical to produce, and makes it possible to obtain good homogenization of the liquids mixed.
According to the invention, a static mixer for homogenizing a mixture of at least two liquids, in particular after injection of an auxiliary liquid into a main liquid, is characterized in that it comprises:
The first wall can be formed by the top of the container, and the opposite wall formed by the bottom, the input duct being vertical when the mixer is in the position of work, starting from the top and extending as far as the vicinity of the bottom, whereas the output duct starts in the vicinity of the top and extends as far as the bottom.
According to a variant, the input duct is horizontal, as is the output duct.
Advantageously, the input duct is arranged in the vicinity of the lateral wall of the container, and in particular against the wall.
The output duct can be arranged in the vicinity of the input duct, in particular against the input duct, or it can be offset from it.
The mixer according to the invention induces an eddying flow of the mixture in order to go from the input duct to the output duct, which gives rise to an effect of high homogenization.
In the lower part, the input duct can have a partially open transverse cross-section, the open part of this cross-section being closed substantially by the wall of the container.
The container can have an oval horizontal cross-section, which in particular is elliptical, and the input duct is situated in the vicinity of an end of the large axis of the cross-section, whereas the output duct is situated substantially against the input duct, on the side of the center of the cross-section. The horizontal cross-section of the container can also be circular. Advantageously, the plane of the parallel axes of the input duct and of the output duct contains the large axis of the horizontal cross-section of the mixer.
The top and the bottom of the container can be curved in order to assist the flow of the fluid in the mixer, and ensure good resistance to the pressure.
Preferably, the container is relatively flat, and has a thickness, according to a direction orthogonal to the plane of the axes of the input duct and of the output duct, the ratio of which to the width of the container is between 0.3 and 0.7.
In the case when the container has an oval cross-section, and in particular elliptical, the thickness of the container corresponds to the small axis of the cross-section, whereas the width corresponds to the large axis.
The mixer can be associated with a single pump. According to a variant, the mixer can be produced with two identical half-parts, which are turned and assembled head-to-tail.
The invention also relates to a dosing device for introduction of an auxiliary liquid into a flow of main liquid circulating in a duct, comprising a dosing pump with a differential piston with reciprocal motion in order to collect the auxiliary liquid from a container, this pump comprising a first input for receipt of a flow of main liquid which ensures that the pump is driven, a second input for collection of the auxiliary liquid, and an output for mixing of the auxiliary liquid and the main liquid, this dosing device being characterized in that it comprises a mixer as previously defined arranged at the output of the pump.
The dosing device can comprise a flow divider installed inside the main liquid duct, with the dosing pump being connected in parallel to the flow divider, the first input of the pump being connected by a first pipe to the input of the flow divider, whereas the output of the pump is connected by a second pipe to a neck of the flow divider, the mixer being arranged on the second pipe between the output of the pump and the connection to the neck of the flow divider.
The dosing device can comprise a means for variable throttling of the neck of the flow divider.
The volume of the container is adapted to the dosing pump with which this mixer is used. The volume of the container is advantageously three times the capacity of the dosing pump, or more.
Apart from the above-described arrangements, the invention consists of a certain number of other arrangements which will be described explicitly hereinafter with reference to an embodiment described in relation to the appended drawings, but which is in no way limiting. In these drawings:
With reference to the drawings, and in particular
The top 1a and the bottom 1b, with the associated lateral walls, are in the form of a shell, as can be seen in
The mixer M comprises an input duct 3 which is vertical when the mixer M is in the position of work. The duct 3 starts from the top 1a and extends as far as the vicinity of the bottom of the container, as can be seen in
The mixer M additionally comprises an output duct 4 which is substantially parallel to the input duct 3, starting below and in the vicinity of the top 1a, and extending as far as the bottom 1b. The mean distance between the open upper end of the duct 3 and the top wall 1a is preferably less than 20 mm. The duct 4 is open at the bottom, and passes through the bottom 1b in order to form output piping 4a which is advantageously provided with annular grooves in order to receive a rapid connection device. The annular grooves permit respectively putting into place a seal and a clip in order to retain a rotary nut which ensures the securing on a threaded joining piece.
As a variant, the input and output ducts could be horizontal between a first lateral wall and an opposite wall.
The top 1a and the bottom 1b are curved, such that the flow of liquid which emerges from the duct 3 in the low part meets a curved surface 5 of the bottom 1b (
The container 1 preferably has an oval horizontal cross-section, in particular elliptical as can be seen in
The input duct 3 is situated in the vicinity of the wall of the container, and preferably at an end of the large axis 8 of the cross-section as can be seen in
The output duct 4 is situated substantially against the input duct 3. The geometric axes of the ducts 3 and 4 are situated on a vertical plane which contains the large axis 8 of the horizontal cross-section of the container. As a variant, the output duct can be offset from, i.e. spaced from, the input duct.
The container 1 is relatively flat, i.e. its thickness in a direction orthogonal to the plane of the geometric axes of the ducts 3 and 4 is relatively small in comparison with its width. The thickness of the container 1 corresponds substantially to the dimension of the small axis 7 of the cross-section, whereas the width corresponds substantially to the dimension of the large axis 8. The ratio of the thickness of the container to its width is advantageously between 0.3 and 0.7.
The volume of the container 1 is preferably equal to at least three times the capacity of a dosing pump with a piston with reciprocal motion for which the mixer M would be designed. A volume of 1.5 L for the mixer M is an example of a possible value, for a 3 m3/hour pump with a capacity of 0.5 L.
The top 1a and the bottom 1b are molded separately, then are assembled by arranging the upper half 1a on the lower half 1b, such that the input duct 3 is between the output duct 4 and the adjacent wall of the bottom 1b. The assembly according to the equatorial plane P is ensured by any appropriate connection means, in particular by welding or by adhesion.
The mixer M is then installed in a position such that the geometric axes of the ducts 3 and 4 are vertical, the input piping 3a being in the high part whereas the output piping 4a is in the low part. The input piping 3a is connected to an intake duct in which a mixture of at least two liquids circulates, and must be made more homogenous. The flow of liquid opens into the low part of the duct 3 at a reduced distance, generally of less than 20 mm, from the bottom wall. When the flow of liquid meets the concave surface 5 of the bottom wall, it describes a short trajectory in the direction of the opposite end of the container 1, and rises again, producing eddies, towards the upper end of the output duct 4, in order to flow out via this duct. The upper end of the duct 4 is situated at a short distance from the upper wall of the top 1a, this distance being in particular less than 20 mm.
The eddies created in the mixture 1 for the passage of the flow of liquid from the lower end of the duct 3 to the upper end of the duct 4, in a sufficient volume, makes it possible to homogenize the mixture.
The pump 9 comprises a first input 11 in order to receive a flow of main liquid which ensures that the pump is driven, a second input 12 in order to collect the auxiliary liquid L1 by means of a pipe 13 which is immersed in the tank R, and an output 14 for the mixing of auxiliary liquid and main liquid.
The mixer M is arranged such that its ducts 3, 4 are vertical, and the input connection piping 3a is connected to the output 14 of the pump 9 by a pipe 15, in particular a flexible pipe. The output piping 4a of the mixer is connected to the duct C.
In the particular example illustrated in
According to the arrangement in
A flap valve 18 which can break a possible vacuum is advantageously provided at the orifice for connection of the flow divider V to the output piping 4a of the mixer.
The diameter of the input piping 3a is at least equivalent to the diameter of the output 14 of the pump.
The volume of the container of the mixer M is at least equal to three times the capacity of the pump 9. The capacity corresponds to the volume which is displaced during an outward and return course of the differential piston 10.
According to a variant, as illustrated in
Whilst being simple and economical to produce, the mixer according to the invention makes it possible to obtain a homogenous mixture of at least two liquids, particularly with a relatively small dose of auxiliary liquid, which in particular is less than 5% of the main liquid.
| Number | Date | Country | Kind |
|---|---|---|---|
| 14 50195 | Jan 2014 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2015/050094 | 1/6/2015 | WO | 00 |
