FR3058074A1 - DEVICE FOR SEPARATING SOLID PARTICLES SUSPENDED IN A LIQUID AND / OR LIQUIDS OF DIFFERENT DENSITY, COMPRISING EACH AT LEAST ONE MEANS OF CREATING AND MAINTAINING VORTEX - Google Patents

Abstract

The device of the invention consists of a combination of the following means: a means for creating and maintaining a vortex by setting in motion the liquid containing solid particles or the mixture of liquids of different densities; the shape and / or the ratio between dimensions of the means respecting the golden ratio φ, - a buffer tank in which the vortex is created, whose shape and / or the ratio between dimensions respect the golden ratio φ, which makes it possible to maintain and if necessary create the vortex, - a central collector along the axis of the reservoir to collect the solid particles concentrated at the bottom of the vortex.

Description

Technical area

The present invention relates to the field of physical separation of solid particles suspended in a liquid and / or liquids of different densities.

It relates more particularly to a mechanical separation device which uses the effect of the centripetal force and therefore implements a means of creating and maintaining a vortex to achieve the desired separation of solid particles from a liquid or from a more liquid dense than another liquid with which it is mixed.

Prior art

In the field of mechanical separation of heterogeneous mixtures, a technique widely used in the industry consists in implementing centrifugation by the action of centrifugal force, which causes the phases involved in a rotational movement.

Centrifugation by centrifugal force can separate two liquid phases, a solid phase suspended in a liquid phase, or even two liquid phases containing a solid phase.

Thus, this technique consists in accelerating the liquid containing solid particles by a mechanically driven rotor, in order to project the heaviest particles towards the outside and to concentrate the liquid freed from the particles or the least dense liquid in the central part of the centrifuge. Patent application US2016 / 0236208 discloses an example of a centrifugal separator dedicated to the separation of solid particles from a liquid phase in which they are mixed.

For two liquids of different densities, the densest liquid is ejected outward, that is to say towards the peripheral wall of the centrifuge while the least dense liquid is collected in the center. Such separation by centrifugation is, for example, implemented for the extraction of water present in petroleum or else plasma present in human blood. Mention may be made here of patent US8182408B2 which relates to a centrifugal separator for the separation of liquids of different densities.

If the known mechanical separators by the action of centrifugal force are generally satisfactory in terms of separation efficiency, they have a certain number of drawbacks which can be listed as follows.

Centrifugation requires rotating the rotor at high rotational speeds. Indeed, the separation efficiency depends directly on the speed of rotation. This leads first of all to a significant consumption of electrical energy and also to wear by abrasion of the materials of the rotor and of the fixed envelope around (stator), as well as a rise in temperature. This wear therefore requires the use of materials more resistant to abrasion and therefore expensive.

In addition, the speed of rotation fairly precisely defines the size and / or mass of the solid particles to be separated, which can be an advantage but which requires the implementation of several speeds of rotation when it is desired to extract particles of sizes and / or different masses.

Finally, the rise in temperature induced by the high speed rotation of the rotor, can be detrimental for certain solid products which it is desired to separate. This can for example degrade organic products or heat-sensitive products.

Another disadvantage of centrifugal separation is that the projection of solid particles towards the outside on the wall of the stator can lead to a harmful deposit going as far as clogging. Regular maintenance is therefore required.

Yet another drawback is that the rotation of the rotor at high speed generates vibrations which accelerate the fatigue of the materials and stresses the bearings of the motor shaft, as well as noise pollution which is combated by the addition of sound protection. Again, regular maintenance is required.

Finally, in the case of the separation of liquids of different densities, the operation of the rotor can be hampered if the proportion of the liquid which is both the densest and the most viscous is too large compared to the lighter liquid. Indeed, the energy required to rotate the mixture is high and remains high if the rotor remains in contact with the most viscous liquid.

In other words, this induces a high energy consumption which could prove to be prohibitive in certain applications. For example, in a hydrothermal biomass gasification process, the content of the oily phase obtained (biocrude) in the aqueous effluents leaving the reactor is of the order of 10 to 15%.

The inventor thinks that it is not reasonable to envisage on an industrial scale a centrifugal separation for this application due in particular to the high energy consumption which would be required and to the abovementioned disadvantages of centrifugal separators.

There is therefore a need to improve the solid-liquid and / or liquid separation devices of different densities, in particular with a view to overcoming the aforementioned drawbacks of centrifugal separators.

The object of the invention is to meet this need at least in part.

Statement of the invention

To do this, the invention relates, in one of its aspects, to a device for separating solid particles suspended in a liquid and / or liquids of different densities comprising:

a buffer tank, of symmetry of revolution about a vertical axis, the tank comprising at least one orifice for injecting liquid loaded with solid particles or at least two liquids of different densities, and an outlet orifice arranged in part lower around the axis of revolution of the tank;

- At least one means for creating and maintaining a vortex generating a centripetal movement of the liquid (s) going from the periphery of the reservoir towards its center over at least part of the height of the latter; the shape and / or the ratio between dimensions of the reservoir and / or of the means for creating and maintaining the vortex is (are) determined from the golden ratio φ;

- a collection tube, arranged below the outlet orifice of the reservoir, for collecting by gravity at least the solid particles, and / or the most dense liquid (s) concentrated towards inside the vortex.

Thus, unlike the solutions of mechanical separators by centrifugation according to the state of the art which eject the solid phase or the densest liquid towards the outside of the rotor, the solution according to the invention consists in using the centripetal movement to concentrate the solid particles or the densest liquid inward.

By "centripetal movement" is meant here and within the framework of the invention, the definition given by the author of the reference [1], namely a convergent, contracting, consolidating, creative movement, favorable to integration. , constructive and friction reducing. In this movement, the radius of rotation decreases progressively, generating an acceleration which intensifies the phenomenon of suction by suction and reduces friction (centripetal acceleration).

The device of the invention consists of a combination of the following means:

- a means of creating and maintaining a vortex by setting in motion the liquid containing solid particles or the mixture of liquids of different densities; the shape and / or the ratio between dimensions of the means respecting the golden ratio φ,

- a buffer tank in which the vortex is created, whose shape and / or ratio between dimensions respect the golden ratio φ, which makes it possible to maintain and if necessary create the vortex,

- a central collector along the axis of the tank to collect the concentrated solid particles at the bottom of the vortex.

Surprisingly, the inventor thought of implementing a centripetal separation after reading the reference [1] for the separation of solid particles mixed in a liquid.

If some have already thought of implementing the principle of centripetal movement, this has been for different problems of the separation of solid particles mixed in a liquid or of separation of two liquids of different densities.

In particular, patent application CN103537211 which relates to the activation and purification of water containing toxic chemical molecules.

Patent application CN103537220 discloses the generation of homogeneous emulsion.

In carrying out the invention, respecting the golden ratio for the shape and / or the ratio of the dimensions of the reservoir will contribute to maintaining the centripetal movement optimally over the height of the reservoir.

In the device according to the invention, the density of the liquid (the least dense in the case of several mixed liquids) means that the speed of rotation of the liquid will be close to zero at the internal wall of the buffer tank. A surface current is created which pushes the liquid towards this internal wall.

This current will continue going down along the wall. Then, towards the bottom of the tank, that is to say near the outlet, the current returns to the center and descends around the central axis of the tank. This current thus drives the solid particles or the densest liquid towards the center at the bottom, that is to say towards the outlet orifice and therefore towards the inside of the collection tube.

In the end, a separator by action of the centripetal force according to the invention has the same general functions of mechanical separation as with centrifugal separators according to the state of the art but without their drawbacks.

Thus, compared with centrifugal separators according to the state of the art, a separator according to the invention has reduced energy consumption, reduced maintenance, a much simpler design and construction which allow a drastic reduction in investment costs. .

It is possible to envisage having a flow rate of solid particles separated and collected by a separation device according to the invention, in the range from 10 kg / h to 1000 tonnes / h.

Thus, the buffer tank of the device according to the invention can have a diameter of a few tens of centimeters to a few meters and the total height of the device can be between 1 and a few tens of meters.

The capacity of the separation device according to the invention can vary from a few liters per hour, typically for domestic applications, to several thousand m ³ / h, typically for industrial applications.

According to a first advantageous variant, the shape of the reservoir is an ovoid of dimensions determined from a regular pentagon.

According to a second advantageous variant, the shape of the reservoir is an ellipsoid of revolution, obtained by rotation around the vertical axis of an ellipse, called the golden ellipse, the ratio of lengths of the major axis and the minor axis being equal the golden ratio.

According to a third advantageous variant, the shape of the reservoir is a hemispherical portion connected to a semi-ellipsoid of revolution, the ellipsoid of revolution obtained by rotation around the vertical axis of an ellipse, called the golden ellipse, the ratio between lengths of the major axis and the minor axis is equal to the golden ratio.

Four distinct alternatives can be provided for the realization of the means for creating and maintaining the vortex. So, it can be:

- A means for injecting the liquid loaded with dissolved particles through one, preferably two injection orifices, tangentially to the buffer tank;

- a cylinder mounted fixed in the injection orifice, the cylinder comprising a groove wound in a circular helix;

- a shaft mounted to rotate vertically along the axis of the reservoir, the shaft having an external shape of a frustoconical helix whose projection on a plane orthogonal to the vertical axis is a logarithmic spiral, called the gold spiral, with a growth factor equal to the golden ratio φ. In this alternative, the free end of the rotary shaft is preferably approximately coincident with the lower top of the tank.

a tree fixed vertically along the axis of the reservoir, the tree having an internal shape of a frustoconical helix whose projection on a plane orthogonal to the vertical axis is a logarithmic spiral, called the gold spiral, with a growth factor equal to the golden ratio φ, the injection orifice being the largest section of the frustoconical propeller.

According to an advantageous characteristic, the outlet orifice is shaped like a frustoconical cone which converges from top to bottom. Preferably, the opening half-angle (a) of the cone is between 6 and 10 °.

According to an advantageous variant, the distance between the upper end of the collection tube and the outlet opening of the reservoir is adjustable so as to be able to modify the collection rate of solid particles.

Advantageously, the device comprises at least one vent in the upper part of the buffer tank for evacuating the gases present.

According to an advantageous embodiment, the device comprises a containment envelope arranged around the outlet orifice and the collection tube, defining an interior volume in which the liquid is confined, with a view to being discharged.

The invention also relates to a separation system comprising at least two devices such as that described above, in which one of the two devices constituting the upstream device comprises at least one discharge orifice, arranged in the lower part of its containment envelope , forming a nozzle connected to the injection port of the buffer tank of the downstream device.

In this system, the upstream device comprises at least one evacuation orifice arranged in the lower part of its confinement envelope, forming a nozzle connected to the injection port of the buffer tank of the downstream device.

Preferably, the confinement envelope of one and / or the other of the two devices consisting of a cylinder connected on the periphery of the reservoir between the injection orifice and the outlet orifice, and a hemisphere-shaped bottom connected to the cylinder.

According to an advantageous embodiment, the system comprises at least one flow control valve between the connection of the upstream device and the injection orifice of the downstream device.

Advantageously, one and / or the other of the two devices can (at least) comprise at least one purge valve on the collection tube to evacuate the collected solid particles.

Advantageously also, the downstream device comprises at least one drain orifice, arranged in the lower part of its confinement envelope, for discharging the liquid devoid of solid particles. Preferably, an isolation valve is provided downstream of the purge orifice, to isolate the confinement envelope of the downstream device.

The invention finally relates to the use of a device as described above for separating the bio-crude from the aqueous effluents, obtained at the outlet of the gasification reactor from an algal biomass.

detailed description

Other advantages and characteristics of the invention will emerge more clearly on reading the detailed description of examples of implementation of the invention made by way of illustration and not limitation, with reference to the following figures among which:

- Figure 1 is a schematic view in longitudinal section of a first example solid-liquid separation device according to the invention;

- Figures 1A and IB are cross-sectional views along A-A and B-B of Figure 1;

- Figures 2 and 2A are respectively a longitudinal sectional view showing a first embodiment of a part of the separation device according to the invention which allows the creation and maintenance of a vortex, and a cross-sectional view along AA;

- Figure 3 is a longitudinal sectional view showing a second embodiment of a part of the separation device according to the invention which allows the creation and maintenance of a vortex;

- Figure 3 A is a side view showing the means for creating and maintaining the vortex according to the mode of Figure 3;

- Figure 4 is a longitudinal sectional view showing a fourth embodiment of a part of the separation device according to the invention which allows the creation and maintenance of a vortex;

- Figure 5 is a longitudinal sectional view showing a variant of the reservoir and its outlet orifice with a means for creating and maintaining the vortex according to Figure 4;

- Figure 6 is a schematic view showing a separation system comprising two solid-liquid separation devices according to the invention, upstream of one another.

It is specified that the various elements according to the invention are represented only for the sake of clarity and that they are not to scale.

The terms “upper”, “lower”, “above” and “below” are to be considered in relation to the buffer tank of the separation device according to the invention, in configuration with the inlet port of the solid-liquid mixture in top and the collection tube at the bottom.

The terms “upstream” and “downstream” are to be considered in relation to the circulation of the liquid in a device and a system according to the invention.

A device 1 for separating solid particles suspended in a liquid is illustrated in FIG. 1.

It firstly comprises a buffer tank 2 of symmetry of revolution about a vertical axis X. In the embodiment illustrated in FIG. 1, the shape of the tank 2 is an ovoid of dimensions determined from a regular pentagon .

The reservoir 2 is pierced with two injection orifices 20, 21, through which the liquid loaded with solid particles can be injected, and with an outlet orifice 22 arranged in the lower part around the axis of revolution X.

In the illustrated embodiments, the outlet orifice 22 is shaped like a frustoconical cone which converges from the top to the bottom. Preferably, the opening half-angle a of the cone is between 6 and 10 °, typically equal to about 8 °.

According to the invention, a means 3 for creating and maintaining a vortex V generates a centripetal movement of the liquid (s) going from the periphery of the reservoir 2 towards its center over at least part of the height of the latter .

According to the invention also, the means 3 are conceived such that its shape and / or the ratio between its dimensions is (are) determined (s) from the golden ratio φ.

Several different embodiments can be envisaged for the realization of this means of creating and maintaining the vortex V.

In the mode illustrated in FIGS. 2 and 2A, the means 3 is a means for injecting the liquid loaded with solid particles tangentially in the upper part of the buffer tank 2.

The injection orifices 20, 21 are for this purpose made on one of the upper diameters of the reservoir and the vortex is generated tangentially to this diameter as symbolized by the arrows in these Figures 2 and 2A.

In the mode illustrated in FIGS. 3 and 3A, the means is a cylinder 31 fixedly mounted in the injection orifice 20 along the axis of revolution X. The cylinder 31 comprises a groove 310 wound in a circular helix.

Thus, this cylinder 31 constitutes, as it were, an injector which allows the liquid to rotate until generating the desired vortex V.

Instead of hydraulic solutions as in the aforementioned modes, one can envisage a mechanical solution to create and maintain the vortex V.

Thus, in the mode illustrated in FIGS. 4 and 5, the means is a shaft 32 mounted to rotate vertically along the axis X of the tank 2.

The shaft 32 has an outer shape of a frustoconical propeller whose projection on a plane orthogonal to the vertical axis is a logarithmic spiral, called the golden spiral, with a growth factor equal to the golden ratio φ.

Preferably, the free end 33 of the rotary shaft 32 is approximately coincident with the lower top of the tank.

Two examples of sizing of a rotary shaft 32 are given in the table below.

It is specified that in this table, the values of the dimensions of the different sections including given from the top of the tree 32 downwards, according to the height of its propeller H.

The position indicates to which height hill each section is considered. The zero value position indicating the top of the rotary shaft propeller.

It is also specified that the height of the propeller is approximately equal to 435.5 mm for example 1, while it is of the order of 609.6 mm for example 2.

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BOARD

Sizing examples of rotary shaft 32 Length (mm) Width (mm) Position (mm) Example 1 15.00 9.27 0 9.27 5.73 166.3 5.73 3.54 269.1 3.54 2.19 332.6 2.19 1.35 371.9 1.35 0.84 396.2 0.84 0.52 411.2 Example 2 21.00 13.00 0 13.00 8.00 232.9 8.00 5.00 376.9 5.00 3.00 465.7 3.00 1.85 520.7 1.85 1.15 554.7 1.15 0.71 575.7

At the outlet of the vortex, a collection tube 4 is arranged below the outlet orifice 22 of the tank 2 to collect by gravity the solid particles concentrated towards the inside of the vortex.

Advantageously, the distance D between the upper end of the collection tube 4 and the outlet orifice 22 of the tank is provided to be adjustable. This allows you to change the collection rate of solid particles. To obtain such a variable distance, a tube 4 of variable height and / or a variable height of the lower volume can be provided between the orifice 22 and the tube 4.

Preferably, a vent with an isolation valve 5 is provided in the upper part of the buffer tank 2 to evacuate the gases present. This can in particular make it possible to evacuate the gases initially present in the solid-liquid mixture.

The separation device according to the invention finally comprises a confinement envelope 6 arranged around the outlet orifice 22 and the collection tube 4. This envelope 6 thus defines an interior volume in which the liquid initially loaded with particles, and the where appropriate the least dense particles is (are) confined (s) in order to be evacuated (s) by the collection tube 4.

Thus, as shown in FIG. 1, the envelope 6 comprises one or more evacuation orifices 60, 61, arranged in the lower part. The remaining liquid, possibly loaded with less dense particles can thus be continuously discharged from the envelope 6.

For the sake of simplicity of construction, the confinement envelope 6 may consist of a cylinder 63 connected to the periphery of the reservoir 2, between the injection orifice 20, 21 and the outlet orifice 22, and d 'a hemisphere-shaped bottom 64 connected to the cylinder 63.

When it is desired to collect particles of different densities and / or particle sizes, it is advantageously possible to envisage making a system with several separation devices which have just been described and putting them in series.

Such a system with two devices 1.1, 1.2 according to the invention, in series is illustrated in FIG. 6.

In this system, the two evacuation orifices 60, 61 of the upstream device 1.1 which make it possible to evacuate the liquid loaded with less dense particles and / or of smaller size and which are arranged in the lower part of the confinement envelope 6 , form nozzles each connected to one of the injection orifices 20, 21 of the buffer tank 2 of the downstream device 1.2.

On each line connecting a nozzle 60, 61 of the upstream device 1.1 to an injection orifice 20, 21 of the downstream device, a flow control valve 7 is arranged.

Two purge valves 8, 9 forming a sealed airlock are arranged on the collection tube 4 of the upstream device 1.1 to evacuate the densest collected solid particles.

The downstream device 1.2 for its part comprises at least one purge orifice 10 arranged in the lower part of its confinement envelope 6, for discharging the liquid devoid of solid particles. Preferably, an isolation valve 11 is provided downstream of the purge orifice 10 to isolate the containment envelope 6 from the downstream device 1.2.

Thus, the densest and / or larger solid particles can be collected in the collection tube 4 of the upstream device 1.1 and the less dense and / or smaller particles in the tube 4 of the downstream device 1.2

Other variants and improvements can be made without departing from the scope of the invention.

Different types of material can be used to make the reservoir 2, means for creating and maintaining a vortex 31, 32, and the confinement envelope 6. Advantageously, in particular for the components closest to the vortex, these these can be made of copper or stainless steel, preferably coated with one or more thin layers based on copper and / or silver.

The invention is not limited to the examples which have just been described; one can in particular combine together characteristics of the examples illustrated within variants not illustrated.

Reference cited [1]: Alick Bartholomew, “The genius of Viktor Schauberger: what if the shortage of water and energy was a false problem? ”, Trédaniel editions / Le courier du livre, 2014 ( ^1st ed. 2008 (ISBN 2-7029-0542-0).

Claims (22)

1. Device (1) for separating solid particles suspended in a liquid and / or liquids of different densities comprising: - a buffer tank (2), of symmetry of revolution about a vertical axis (X), the tank comprising at least one injection orifice (20, 21) in liquid loaded with solid particles or in at least two liquids different densities, and an outlet orifice (22) arranged in the lower part around the axis of revolution of the tank; - at least one means (3) for creating and maintaining a vortex generating a centripetal movement of the liquid (s) going from the periphery of the reservoir towards its center over at least part of the height of the latter; the shape and / or the ratio between dimensions of the reservoir and / or of the means for creating and maintaining the vortex is (are) determined from the golden ratio φ; - a collection tube (4), arranged below the outlet opening of the tank, for collecting by gravity at least the solid particles, and / or the liquid (s) the densest (s) ) concentrated towards the inside of the vortex. 2. Device (1) according to claim 1, the shape of the reservoir being an ovoid of dimensions determined from a regular pentagon. 3. Device (1) according to claim 1, the shape of the reservoir being an ellipsoid of revolution, obtained by rotation around the vertical axis of an ellipse, called a golden ellipse, the ratio between lengths of the major axis and of the minor axis is equal to the golden ratio. 4. Device (1) according to claim 1, the shape of the reservoir being a hemispherical portion connected to a semi-ellipsoid of revolution, the ellipsoid of revolution obtained by rotation around the vertical axis of an ellipse, called ellipse d 'gold, whose ratio between lengths of the major axis and the minor axis is equal to the golden ratio. 5. Device (1) according to one of claims 1 to 4, the means for creating and maintaining the vortex being a means (30) for injecting the liquid loaded with particles in suspension by one, preferably two injection orifices , tangentially to the buffer tank. 6. Device (1) according to one of claims 1 to 4, the means for creating and maintaining the vortex being a cylinder (31) fixedly mounted in the injection orifice (20) the cylinder comprising a groove (310 ) wound in a circular helix. 7. Device (1) according to claim 1 to 4, the means for creating and maintaining the vortex being a shaft (32) rotatably mounted vertically along the axis of the reservoir, the shaft having an outer helix shape frustoconical whose projection on a plane orthogonal to the vertical axis is a logarithmic spiral, called the golden spiral, with a growth factor equal to the golden ratio φ. 8. Device (1) according to claim 7, the free end (33) of the rotary shaft being approximately coincident with the lower top of the tank. 9. Device (1) according to claim 1 to 4, the means for creating and maintaining the vortex being a tree fixed vertically along the axis of the reservoir, the tree having an internal shape of frustoconical helix whose projection on a plane orthogonal to the vertical axis is a logarithmic spiral, called a gold spiral, with a growth factor equal to the golden ratio φ, the injection orifice being the largest section of the frustoconical helix. 10. Device (1) according to any one of the preceding claims, the outlet orifice (22) being shaped as a truncated cone which converges from top to bottom. 11. Device according to claim 10, the opening half-angle (a) of the cone being between 6 and 10 °. 12. Device (1) according to any one of the preceding claims, the distance between the upper end of the collection tube (4) and the outlet orifice (22) of the reservoir being adjustable so as to be able to modify the rate of collection of solid particles and / or the most dense liquid (s). 13. Device (1) according to any one of the preceding claims, comprising at least one vent (5) in the upper part of the buffer tank for evacuating the gases present. 14. Device (1) according to any one of the preceding claims, comprising a confinement envelope (6) arranged around the outlet orifice and the collection tube, defining an interior volume in which the liquid initially charged with particles, the least dense particles and / or the least dense liquid (s) is (are) confined (s) in order to be evacuated (s). 15. A separation system (8) comprising at least two devices (1) according to claim 14, in which one of the two devices constituting the upstream device (1.1) comprises at least one discharge orifice (60, 61) arranged in part bottom of its containment envelope, forming a nozzle connected to the injection port of the buffer tank of the downstream device (1.2). 16. A separation system according to claim 15, the containment envelope of one and / or the other of the two devices consisting of a cylinder (63) connected on the periphery of the tank (2) between the orifice. injection (20, 21) and the outlet orifice (22), and a hemisphere-shaped bottom (64) connected to the cylinder. 17. Separation system according to claim 15 or 16, comprising at least one flow control valve (7) between the inlet of the upstream device and the injection port of the downstream device. 18. Separation system according to one of claims 15 to 17, one and / or the other of the two devices comprising at least one purge valve (8, 9) on the collection tube for evacuating the collected solid particles and / or the most dense liquid (s). 19. System according to one of claims 15 to 18, the downstream device comprising at least one drain orifice (10) arranged in the lower part of its confinement envelope, for discharging the liquid devoid of solid particles and / or the liquid less dense. 20. The system of claim 19, comprising an isolation valve (11) downstream of the purge orifice (10) to isolate the containment of the downstream device. 21. Use of a device according to one of claims 1 to 14 or of the system according to one of claims 15 to 20 for separating solid particles suspended in a liquid according to their particle size or liquids according to their density. 22. Use of a device according to one of claims 1 to 14 or of the system according to one of claims 15 to 20, for separating the bio-crude from the aqueous effluents, obtained at the outlet of the gasification reactor from a biomass algal. 2/4 3Z4 x ι r  ί Ί P ί 20 \ ι 1 ^ 22 4Z4