Mixing device for multiple components and associated method

Abstract

The invention relates to a multi-component mixing device (10) comprising at least a first feed (12) of a first product and a second feed (14) of a second product. The mixing device (10) has a mixing chamber (16) having at least a first inlet and a second inlet (24), the first feed (12) opening into the mixing chamber (16) at the first inlet and the second feed (14) opening into the mixing chamber (16) at the second inlet (24). The mixing device (10) includes a nozzle (18) arranged and adapted to inject the second product from the second feed (14) into the mixing chamber (16) in the form of a flat jet. The invention further relates to an associated mixing method.

Description

[0001] The present invention relates to a multi-component mixing device comprising at least a first feed of a first product and a second feed of a second product, the mixing device having a mixing chamber having at least a first inlet and a second inlet, the first feed opening into the mixing chamber at the first inlet, the second feed opening into the mixing chamber at the second inlet.

[0002] The present invention further relates to an associated mixing method.

[0003] Such a mixing device makes it possible, for example, to mix a base with a catalyst to form a coating product, shortly before coating.

[0004] In particular, there are mixing devices comprising a mixing chamber having a catalyst inlet and a product base inlet. The product base is introduced into the mixing chamber in the form of a stream, the catalyst being injected in the form of a trickle.

[0005] However, the catalyst then forms a net in the base stream.

[0006] One possibility is to provide one or more mixing elements, such as a propeller or a static mixer.

[0007] However, this complicates the device, and thus its maintenance, particularly its cleaning.

[0008] Additionally, a propeller or static mixer is likely to have preferential flow paths, so that the mixture is not homogeneous at the outlet.

[0009] GB 2 036 586 A, US 2003 / 0224308 A1 and US 6 590 052 B2 describe various mixing chambers, according to the preamble of claim 1.

[0010] An aim of the invention is therefore to improve the mixing device to enable better mixing.

[0011] For this purpose, the invention relates to a mixing device according to claim 1.

[0012] Injecting the second product into the mixing chamber in the form of a flat jet, into which the first product is introduced, allows for a better distribution of the second product in the first product and a better contact surface between the two products. The first product and the second product are mixed homogeneously at the outlet of the mixing chamber.

[0013] The device may further have one or more of the additional features of claims 2 to 8, considered individually or in any technically possible combination.

[0014] The invention further relates to a mixing method according to claim 9.

[0015] Other features and advantages of the invention will become apparent upon reading the following description of embodiments of the invention, given by way of example only and with reference to the drawings in which: [ Fig 1 ] there figure 1 is a front view showing a section along a first section plane II of a device according to an embodiment of the invention, [ Fig 2 ] there figure 2 is a side view showing a section along a second section plane II-II of the device of the figure 1 , [ Fig 3 ] there figure 3 is a perspective view showing a section along the second section plane II-II of a portion of the device of the figure 1 , [ Fig 4 ] there figure 4 is a top view showing a section along a third section plane IV-IV of the device of the figure 1 , And [ Fig 5 ] there figure 5 is a front view of the nozzle of the device of the figure 1 .

[0016] An example of a multi-component mixing device 10 according to an embodiment of the invention is shown in the figure 1 à 5 .

[0017] The mixing device 10 comprises at least a first supply 12 of a first product and a second supply 14 of a second product, a mixing chamber 16 and a nozzle 18.

[0018] By nozzle is meant a means capable of making or letting pass a product of any viscosity, also called an injector or insert, for example a split nozzle as described below.

[0019] The mixing chamber 16 delimits a mixing space 20.

[0020] The mixing chamber 16 is, for example, made of stainless steel.

[0021] The mixing chamber 16 has at least a first inlet 22 and a second inlet 24, and furthermore an outlet 26.

[0022] The mixing chamber 16 has a flow axis D.

[0023] The flow axis D is here substantially vertical. This allows the flow to be facilitated by gravity.

[0024] The mixing chamber 16 extends here between a first end and a second end along the flow axis D.

[0025] The first end here corresponds to an upper end 28 of the mixing chamber 16.

[0026] The second end here corresponds to a lower end 30 of the mixing chamber 16.

[0027] In the example shown, the mixing chamber 16 has substantially the shape of a hollow cylinder with the cylinder axis being the flow axis D.

[0028] The mixing chamber 16 here has a radius of, for example, 7.5 mm.

[0029] The mixing chamber 16 includes a side wall 32 between the upper end 28 and the lower end 30.

[0030] The first entrance 22 is delimited by the side wall 32.

[0031] The side wall 32 is substantially cylindrical.

[0032] The first inlet 22 has the shape of a disc projected onto the side wall 32.

[0033] The second inlet 24 is here arranged at the upper end 28.

[0034] The second inlet 24 is centered on the flow axis D.

[0035] The second entry 24 has the shape of a disc.

[0036] The outlet 26 here corresponds to the lower end 30 of the mixing chamber 16.

[0037] Outlet 26 is centered on the flow axis D.

[0038] Exit 26 is shaped like a disc.

[0039] The first feed 12 opens into the mixing chamber 16 at the first inlet 22.

[0040] The first supply 12 comprises a source of first product (not shown) and a first supply conduit 34.

[0041] The first supply duct 34 is, for example, made of stainless steel.

[0042] The first supply duct 34 comprises a first downstream portion 36, the first downstream portion 36 opening into the mixing chamber 16, more particularly at the level of the first inlet 22.

[0043] In the example shown, the first downstream portion 36 has a cylindrical shape.

[0044] The first feed 12 is adapted to introduce the first product into the mixing chamber 16 along a central feed axis D'.

[0045] The first downstream portion 36 extends here mainly along the central supply axis D'.

[0046] More particularly, the first downstream portion 36 has as its cylinder axis the central supply axis D'.

[0047] The respective directions of the central supply axis D' and the flow axis D form an angle between 0° and 135°, more particularly between 0° and 90°.

[0048] In the case of an angle of 0°, the central supply axis and the flow axis are coincident. The first supply and the second supply are coaxial. More particularly, the first inlet extends around the second inlet. The first inlet has, for example, a ring shape, and the second inlet has a disc shape surrounded by the inner diameter of the ring.

[0049] The selected angle allows in particular to obtain more or less turbulence or a flow closer to a laminar flow.

[0050] In the example shown, the central supply axis D' is orthogonal to the flow axis D. The central supply axis D' extends in a plane perpendicular to the flow axis D.

[0051] The central supply axis D' is, for example, horizontal.

[0052] The central supply axis D' and the flow axis D each define a respective straight line.

[0053] The lines defined by the central supply axis D' and by the flow axis D are not intersecting.

[0054] The lines have a minimum distance d from each other, corresponding to the distance between the lines.

[0055] The distance d is non-zero.

[0056] Said non-zero distance d is subsequently called offset 38 between the central supply axis D' and the flow axis D.

[0057] The difference is substantial, that is to say not negligible, that is to say visible to the naked eye.

[0058] The offset is between 3% of the mixing chamber radius value and the mixing chamber radius value, more specifically between 10% of the mixing chamber radius value and the mixing chamber radius value.

[0059] More specifically here, the offset is between 2.0 millimeters (mm) and 6.0 mm for a mixing chamber of radius 6.0 mm.

[0060] Said offset allows in particular that the first product flows with a swirl effect in the mixing space 20.

[0061] This makes it possible in particular to facilitate mixing in the mixing chamber 14 by creating turbulence.

[0062] The distance in the direction of the flow axis D between the first inlet 22 and the second inlet 24 is less than or equal to 15.0 mm, preferably 13.0 mm, preferably 12.0 mm.

[0063] The distance in the direction of the flow axis D extending between the first inlet 22 and the second inlet 24 corresponds, in the example shown, to the distance between the second inlet 24 and a so-called upper end of the first inlet 22 in the direction of the flow axis D.

[0064] The first feed 12 is here adapted to generate a continuous flow of first product at the first inlet 22.

[0065] The first supply conduit 34 is, for example, without a valve.

[0066] Alternatively, the first supply conduit 34 is provided with a valve configured to control the flow of first product at the first inlet 22.

[0067] The first feed 12 is devoid of a nozzle adapted to inject the first product from the first feed into the mixing chamber in the form of a flat jet. More particularly here, the first feed 12 is devoid of any nozzle.

[0068] The second feed 14 opens into the mixing chamber 16 at the second inlet 24.

[0069] The second supply comprises a source of second product (not shown) and a second supply conduit 40.

[0070] The second supply duct 40 is, for example, made of stainless steel.

[0071] The second supply conduit 40 has an interior surface 41 delimiting the passage of the second product.

[0072] The second supply duct 40 comprises a second downstream portion 42, the second downstream portion 42 opening into the mixing chamber 16, more particularly at the level of the second inlet 24.

[0073] The second supply 14 is adapted so that the second product has a pressure, more particularly at the level of the second inlet 24, strictly greater than the pressure of the first product, more particularly at the level of the first inlet 22.

[0074] The pressure of the first product is, for example, between 1 bar, or 1.10 5< Pa, and 500 bar, or 5.10 7< Pa.

[0075] The pressure of the second product is greater than the pressure of the first product by at least 1.0%, generally at least 5.0%.

[0076] This value depends in particular on the viscosity of each of the products to be mixed.

[0077] This helps to improve the homogenization of the mixture.

[0078] The nozzle 18 is arranged and adapted to inject the second product from the second feed 14 into the mixing chamber 16 in the form of a flat jet.

[0079] The jet has a jet angle α, at the nozzle outlet, between 50° and 80°.

[0080] The nozzle 18 is arranged to inject the second product around a central injection axis, the central injection axis being aligned, or merged, with the flow axis D.

[0081] The entire second product passes through the nozzle 18 before reaching the mixing chamber 16.

[0082] The nozzle 18 is, for example, made of cast carbide, more particularly tungsten, 316 stainless steel or ceramic.

[0083] The nozzle 18 is here arranged in the second feed 14 near the second inlet 24.

[0084] The nozzle 18 is housed in the second supply duct 40, more particularly in the second downstream portion 42.

[0085] In the example shown, the nozzle 18 is held in the second supply duct 40 by a nozzle holder 43 described below.

[0086] The nozzle 18 has an external shape which here has rotational symmetry around the central injection axis D.

[0087] The nozzle 18 has a downstream end 44, the downstream end 44 corresponding to the most downstream point of the nozzle 18 considering the flow of the second product.

[0088] The downstream end 44 is here arranged close to the second inlet 24.

[0089] The downstream end 44 and the second inlet 24 are, for example, spaced apart by a distance strictly less than 5.0 mm, preferably 3.0 mm, preferably 2.0 mm.

[0090] The downstream end 44 is, for example, upstream of the second inlet 24 by said distance. The injection of the second product sends the second product into the mixing chamber 16.

[0091] Alternatively, the downstream end 44 extends downstream of the second inlet 24 into the mixing chamber 16. Thus, the nozzle 18 protrudes slightly at the downstream end 44 into the mixing chamber 16.

[0092] The distance e in the direction of the flow axis D between the first inlet 22 and the downstream end 44 is less than or equal to 10.0 mm.

[0093] The distance in the direction of the flow axis D between the first inlet 22 and the downstream end 44 corresponds, in the example shown, to the distance between the downstream end 44 and the upper end of the first inlet 22 in the direction of the flow axis D.

[0094] The nozzle 18 extends between the downstream end 44 and an upstream end 46 along the central injection axis D.

[0095] The nozzle 18 has an upstream face 48, housed in the second supply duct, and a downstream face 50, opposite the upstream face 48 and facing the mixing chamber 16.

[0096] The upstream face 48 delimits the upstream end 46.

[0097] The downstream face 50 delimits the downstream end 44.

[0098] The upstream face 48 is substantially flat and is arranged substantially transversely to the central injection axis D.

[0099] The downstream face 50 is dome-shaped centered on the central injection axis D and split with at least one, in the example shown a single, slot 52 perpendicular to the central injection axis D.

[0100] The slot 52 has lips 54 which form between them an angle typically between 5° and 150°, preferably between 20° and 110°.

[0101] The nozzle 18 here has an external shape comprising two cylindrical sections, a first cylindrical section 56 delimiting the upstream face 48 and a second cylindrical section 58 ending in a dome delimiting the downstream face 50.

[0102] Each cylindrical section has the central injection axis D as its cylinder axis.

[0103] The first cylindrical section 56 has a diameter strictly greater than the diameter of the second cylindrical section 58.

[0104] The nozzle 18 then defines an external shoulder 60 on its external surface.

[0105] The shoulder 60 is here circumferential.

[0106] The nozzle 18 delimits at least one passage 64.

[0107] In the example shown, the nozzle 18 delimits a single passage 64.

[0108] Alternatively, the nozzle 18 delimits a plurality of passages, for example between two and ten passages.

[0109] The nozzle 18 delimits at least one ejection orifice 62, in the example shown a single one, the or each ejection orifice 62 opening here into the downstream face 50.

[0110] The nozzle 18 here comprises as many passage(s) 64 as slot(s) 52 and as many ejection orifice(s) 62.

[0111] The or each ejection orifice 62 here forms a portion of the passage 64 or of a respective passage, more particularly the portion of the passage furthest downstream.

[0112] In the example shown, the or each passage 64 further comprises an inlet cavity 66 in the nozzle, followed by a channel 68.

[0113] More particularly, the or each passage 64 is constituted, from upstream to downstream, of the inlet cavity 66, the channel 68 and the ejection orifice 62.

[0114] Cavity 64 opens into the upstream face 48.

[0115] Cavity 64 has a cross-section decreasing downstream.

[0116] The inlet cavity 64 here has rotational symmetry around the central injection axis D, the diameter of the inlet cavity 64 decreasing from the upstream end 46 or the upstream face 48 of the nozzle 18 to the channel 66.

[0117] The cavity 64 has, in the example shown, a bell shape.

[0118] Channel 66 has a constant cross-section.

[0119] Channel 66 here has a cylindrical shape with cylinder axis and central injection axis D.

[0120] Channel 66 extends in continuity with inlet cavity 64.

[0121] The ejection orifice 62 comprises, more particularly is formed by, from upstream to downstream, a narrowing 70 of the passage and of the slot 52 or of a respective slot.

[0122] The constriction 70 forms a constriction of the channel 68 at a downstream end of the channel 68.

[0123] The narrowing 70 forms a circular passage section.

[0124] The narrowing 70 has, for example, a dome shape split by the slot 52.

[0125] The slot 52 has a dimension increasing from upstream to downstream.

[0126] The intersection 72 of the slit 52 and the narrowing 70 forms an ellipse.

[0127] The ellipse has an equivalent diameter of 0.3 mm and 2.0 mm, that is, it has an area equal to the area of a circle with the equivalent diameter.

[0128] The nozzle holder 43 is adapted to carry the nozzle 18 and keep it secured to the second supply duct 40.

[0129] The nozzle holder 43 is, for example, made of stainless steel.

[0130] The nozzle holder 43 here has rotational symmetry around the central injection axis D.

[0131] The nozzle holder 43 here comprises an outer surface 74 capable of cooperating with the inner surface 41 of the second supply duct 40.

[0132] The inner surface 41 of the second supply duct 40 has, for example, a thread, and the outer surface 74 has a thread complementary to the thread.

[0133] Alternatively, the nozzle holder 43 is shrunk into the second feed duct 40, for example, hot, so that the outer surface 74 extends against the inner surface 41 of the second feed duct 40.

[0134] The nozzle holder 43 has an upstream face 76 and a downstream face 78 along the central injection axis D.

[0135] The nozzle holder 43 further delimits a housing 80 provided to receive the nozzle 18, more particularly in a downstream portion of the nozzle holder 43.

[0136] The housing 80 is, for example, a through orifice along the central injection axis D.

[0137] The through-orifice is delimited by an inner surface 81 of the nozzle holder 43.

[0138] The through hole opens on the one hand into the upstream face 76 and on the other hand into the downstream face 78.

[0139] The cross-section of the through-hole decreases from upstream to downstream.

[0140] The through hole has a shoulder 82.

[0141] The shoulder 82 is formed by a narrowing of the through-orifice going from upstream to downstream.

[0142] The shoulder 60 of the nozzle 18 cooperates with the shoulder 82 of the nozzle holder 43.

[0143] A seal 84 is here arranged between the shoulder 60 of the nozzle 18 and the shoulder 82 of the nozzle holder 43.

[0144] The seal 84 is, for example, made of polytetrafluoroethylene (PTFE).

[0145] Alternatively, gasket 84 is replaced with glue.

[0146] The shoulder 82 of the nozzle holder 43 forms a stop for the nozzle 18 along the central injection axis D in the upstream to downstream direction.

[0147] The nozzle 18 is, in addition, held along the central injection axis D in the downstream to upstream direction by a second stop system.

[0148] The through hole here delimits in an upstream portion a complementary imprint 85 of a tool, for example an imprint with a hexagonal section.

[0149] This makes it possible in particular to use a tool to fix the nozzle holder 43 in the second supply duct 40, for example by screwing the nozzle holder 43 using the tool into the second supply duct 40.

[0150] A seal 86 is further arranged here between the nozzle holder 43 and the inner surface 41 of the second supply duct 40.

[0151] The seal 86 is, for example, made of PTFE.

[0152] The nozzle 18 is received in the nozzle holder 43, so that the downstream end 44, here more particularly the entire downstream face 50, of the nozzle 18 protrudes from the nozzle holder 43 at the level of the downstream face 78.

[0153] The second supply 14 further comprises an injection valve 88.

[0154] The injection valve 88 is adapted to selectively allow the passage of the second product therethrough.

[0155] The injection valve 88 is here arranged in the second supply, more particularly in the second supply conduit 40, upstream of the nozzle 18.

[0156] The injection valve 88 here comprises a system comprising an element 90 movable relative to a seat 92, designed to allow the passage of the second liquid when the element is moved away from the seat and to prevent the passage of the second liquid when the element extends against the seat.

[0157] The seat 92 delimits a passage 95 having a cross-section decreasing from upstream to downstream.

[0158] The passage has, for example, a truncated cone shape.

[0159] The second feed is such that the second product of the second feed necessarily passes through the passage 95 delimited by the seat 92 before reaching the nozzle 18 and / or the mixing chamber 16.

[0160] The seat 92 is here fixed relative to the nozzle 18.

[0161] More particularly, the seat 92 is here secured to the nozzle holder 43, for example via a holding element 96.

[0162] The holding element 96 has an outer surface 98 intended to cooperate with the inner surface 81 of the nozzle holder.

[0163] The outer surface 98 has, for example, a thread complementary to a thread of the inner surface 81 of the nozzle holder.

[0164] The holding element 96 further has a shoulder 100 capable of holding the seat along the central injection axis in the direction from downstream to upstream.

[0165] The holding element 96 has, in the example shown, an imprint 102 complementary to a tool.

[0166] The imprint 102 corresponds, for example, to a slot perpendicular to the central injection axis. The imprint 102 is, for example, complementary to a screwdriver.

[0167] This allows in particular the use of a tool for installing the holding element 96 in the nozzle holder.

[0168] The seat 92 rests downstream on the nozzle 18.

[0169] Thus, the seat 92 forms the second stop system of the nozzle 18 along the central injection axis D, while the nozzle 18 forms a stop system of the seat 92 along the central injection axis for the direction from upstream to downstream.

[0170] A seal 104 is here arranged between the seat 92 and the nozzle 18.

[0171] The seal 104 is, for example, made of PTFE.

[0172] Thus, the nozzle 18, here in addition the seal 104, and the seat 92 are held fixed relative to the nozzle holder 43 along the central injection axis D by the shoulder 60 on the one hand, and by the holding element secured to the nozzle holder 43 on the other hand.

[0173] Alternatively, the seat 92 is attached directly to the nozzle holder 43.

[0174] The movable member 90 is controllable to selectively open or close the passage 95 through the seat.

[0175] More particularly here, the element 90 comprises a ball 106 carried at one end of a needle 108.

[0176] The ball 106 is sized so that it closes the passage 95 when it rests on the edges of said passage 95.

[0177] Thus, the injection valve 88 makes it possible to control the passage of the second product through the second supply conduit 40, towards the nozzle 18, and thus injected into the mixing chamber 16.

[0178] The seat 92 and the movable element 90 are, for example, made of stainless steel.

[0179] In the example shown, the device 10 further comprises an air supply 110, the mixing chamber 16 further having an air inlet 112.

[0180] The air supply 110 opens into the mixing chamber 16 at the air inlet 112.

[0181] The air inlet 112 is arranged in the side wall 32 of the mixing chamber 16.

[0182] The air inlet 112 is arranged downstream of the first inlet 22 of the first product in the flow direction D.

[0183] Air is injected radially into the mixing chamber 16.

[0184] This helps to create additional turbulence to promote mixing.

[0185] In an example not shown, the device does not comprise a nozzle holder, the nozzle being attached directly to the inner surface of the second supply duct. The seat, if any, is, for example, then also attached directly to the inner surface of the second supply duct.

[0186] In an alternative not shown, the device comprises more than two product inlets into the mixing chamber, so as to mix more than two products in the mixing chamber. At at least one of the inlets, a nozzle is arranged as described above. More particularly, at all of the inlets except one, a respective nozzle is arranged.

[0187] In another alternative not shown, the device comprises a second mixing chamber similarly comprising a first product inlet and a second product inlet. The second mixing chamber is arranged downstream of the previously described mixing chamber, the outlet of the described mixing chamber forming the feed connected to the first inlet of the second mixing chamber, a feed of a third product being connected to the second inlet of the second mixing chamber. This then makes it possible to mix three products successively.

[0188] The device is thus capable of comprising as many mixing chambers arranged in series as desired, the outlet of each mixing chamber apart from the last one being connected to the first inlet of the following mixing chamber.

[0189] Generally speaking, when mixing a given number n of products, the device here comprises n-1 nozzles, each product inlet being provided with a nozzle with the exception of an inlet for a product called the base of the mixture.

[0190] A method of mounting the device 10 as described with reference to the figures will now be described.

[0191] Said method is capable of being adapted to allow the assembly of the described variants of the device not shown.

[0192] A device comprising a first feed 12, a second feed 14 and a mixing chamber 16 as previously described is provided.

[0193] A nozzle 18 as described is positioned at the second feed 14, so as to inject the second product from the second feed into the mixing chamber in the form of a flat jet.

[0194] More particularly, the nozzle 18 is placed in the nozzle holder 43, here in the through-orifice, more particularly so that the shoulder 60 of the nozzle 18 rests on the shoulder 82 of the nozzle holder 43.

[0195] A seal 84, here annular, for example, advantageously placed between the shoulders 60, 82.

[0196] A seal 104, here annular, is then, for example, placed on the nozzle 18.

[0197] Seat 92 is then placed as previously described.

[0198] Then, the holding element 96 is inserted into the nozzle holder 43, so as to remain secured to said nozzle holder 43. The holding element 96 is, for example, screwed into the nozzle holder 43, for example using a screwdriver.

[0199] The assembly formed here by the nozzle 18, the seat 92, the holding element 96 and, where appropriate, the corresponding seals, is here secured to the nozzle holder 43 in the through-orifice.

[0200] A seal 86, here annular, is arranged on an outer surface of the nozzle holder 43 so as to extend between the nozzle holder 43 and the inner surface 41 of the second supply duct 40.

[0201] The nozzle holder 43 is then inserted into the second supply duct 40 and secured to said second supply duct 40, for example by screwing, for example using an Allen key, or alternatively by shrink fitting.

[0202] The nozzle holder 43 is such that the nozzle 18 injects the second product into the mixing chamber.

[0203] The movable element 90 is then placed, as well as an actuator of the movable element, so that said element is movable between a closing position in which it extends against the seat and a passage position in which it extends away from the seat 92.

[0204] A method of mixing at least a first product and a second product will now be described.

[0205] A device 10 as previously described is provided.

[0206] A first product is supplied at the first inlet 22 into the mixing chamber 16 by the first feed 12.

[0207] A second product is supplied by the second power supply 14.

[0208] The second product has a pressure strictly higher than that of the first product, more particularly by at least 1.0%, generally by at least 5.0%, as described above.

[0209] The second product is injected through the nozzle 18 into the mixing chamber 16 in the form of a flat jet.

[0210] The jet has a jet angle α of between 50° and 80° at the nozzle outlet.

[0211] More particularly, in the example shown, the element 90 is spaced from the seat 92 so as to allow the passage of the second product through the valve 88.

[0212] The second product enters the nozzle 18 and exits the nozzle 18 at the ejection orifice 62.

[0213] The second product is injected as a flat jet onto the first product injected into the mixing chamber.

[0214] This promotes mixing, with the second product and the first product forming a greater contact surface, compared to a bead.

[0215] This allows for better distribution of the second product in the first product. The first product and the second product are thus mixed homogeneously at the outlet of the mixing chamber.

[0216] Such a mixing device makes it possible, for example, to mix a base with a catalyst to form a coating product, particularly in the field of paint.

Claims

1. A multi-component mixing device (10) comprising at least a first supply (12) of a first product and a second supply (14) of a second product, the mixing device (10) having a mixing chamber (16) with at least a first inlet (22) and a second inlet (24), the first supply (12) opening into the mixing chamber (16) at the first inlet (22), the second supply (14) opening into the mixing chamber (16) at the second inlet (24), the mixing device (10) comprising a nozzle (18) arranged and adapted to inject the second product from the second supply (14) into the mixing chamber (16) as a flat jet, advantageously having a jet angle (α) of between 50° and 80°, wherein the nozzle (18) is arranged in the second supply (14), the nozzle (18) comprising a downstream end (44), characterized in that the mixing chamber (16) has a flow axis (D), the distance in the direction of the flow axis (D) between the first inlet (22) and the downstream end (44) is less than or equal to 10.0 mm, the first supply (12) being adapted to introduce the first product into the mixing chamber (16) along a central supply axis (D'), the central supply axis (D') and the flow axis (D) each defining a respective line having a non-zero minimum distance from each other referred to as an offset (38) between the central supply axis (D') and the flow axis (D).

2. The mixing device according to claim 1, wherein the nozzle (18) is arranged in the second supply (14), the nozzle (18) comprising a downstream end (44) arranged at a distance strictly less than 5.0 mm, preferably 3.0 mm, more preferably 2.0 mm, of the second inlet (24).

3. The mixing device according to claim 1 or 2, wherein the second supply (14) is adapted so that the second product has a pressure strictly higher than the pressure of the first product, more specifically of at least 1.0%.

4. The mixing device according to any one of claims 1 to 3, wherein the nozzle (18) delimits at least one passage (64), the or each passage comprising an ejection opening (62) comprising, from upstream to downstream, a circular passage section (70) directly followed by a slot (52), the circular passage section (70) and the slot (52) having an intersection (72), the intersection (72) forming an ellipse.

5. The mixing device of any one of claims 1 to 4, wherein the mixing chamber (16) has a flow axis (D), the nozzle (18) being arranged to inject the second product about a central injection axis, the central injection axis being aligned with the flow axis (D).

6. The mixing device of any one of claims 1 to 5, wherein the mixing chamber (16) has a flow axis (D), the first supply (12) being adapted to introduce the first product into the mixing chamber (16) along a central supply axis (D'), the central supply axis (D') and the flow axis (D) defining an angle between 0° and 135°, more specifically between 0° and 90°.

7. The mixing device according to any one of claims 1 to 6, wherein the offset (38) is advantageously between 3% of the value of a mixing chamber radius and the value of the mixing chamber radius.

8. The mixing device of any one of claims 1 to 7, comprising an air supply (110), the mixing chamber (16) having an air inlet (112), the air supply (110) opening into the mixing chamber (16) at the air inlet (112).

9. A method for mixing at least a first product and a second product, comprising the following steps: - providing a mixing device (10) according to any one of claims 1 to 8, - supplying the first product at the first inlet (22), - supplying the second product to the second inlet (24), and - injecting the second product into the first product in the mixing chamber (16) through the nozzle (18) as a flat jet, advantageously having a jet angle (α) of between 50° and 80°.

Images