Mixing device promoting a homogeneous distribution of a diphasic mixture, heat exchange facility and associated mixing method

Abstract

A mixing device for distributing a mixture of a first phase and a second phase of a first fluid in a longitudinal direction in at least one passage of a heat exchanger, said mixing device including at least one lateral channel configured for the first phase to flow from at least one first inlet; a series of longitudinal channels extending in the longitudinal direction and each configured for the second phase to flow from a second inlet to a second outlet, said longitudinal channels succeeding each other in a lateral direction orthogonal to the longitudinal direction; and at least one opening fluidly connecting said lateral channel to at least one longitudinal channel such that the mixing device is configured to distribute a mixture of the first phase and the second phase via the second outlet of said longitudinal channel.

1 .- 15 . (canceled) 
     
     
         16 . A mixing device for distributing a mixture of a first phase and a second phase of a first fluid in a longitudinal direction in at least one passage of a heat exchanger, said mixing device comprising:
 at least one lateral channel configured for the first phase to flow from at least one first inlet;   a series of longitudinal channels extending in the longitudinal direction and each configured for the second phase to flow from a second inlet to a second outlet, said longitudinal channels succeeding each other in a lateral direction orthogonal to the longitudinal direction; and   at least one opening fluidly connecting said lateral channel to at least one longitudinal channel such that the mixing device is configured to distribute a mixture of the first phase and the second phase via the second outlet of said longitudinal channel,   wherein said at least one longitudinal channel of the mixing device is divided, in the longitudinal direction, into an upstream portion having a length L 3  measured in the longitudinal direction ad a width D 3  measured in the lateral direction, and a downstream portion having a length L 4  measured in the longitudinal direction and a width D 4  measured in the lateral direction, with the downstream portion being arranged between the upstream portion and the second outlet, said downstream portion having, at any point of its length, a width that is greater than the width of the upstream portion.   
     
     
         17 . The device as claimed in  claim 16 , wherein the downstream portion has a continuous increasing width over the entire length toward the second outlet. 
     
     
         18 . The device as claimed in  claim 16 , wherein all or part of the downstream portion has, as a longitudinal section in a plane parallel to the longitudinal direction and to the lateral direction, an external profile in the form of an isosceles trapezoid. 
     
     
         19 . The device as claimed in  claim 16 , wherein the downstream portion emerges at a downstream face of the mixing device, the external profile forming an angle θ, measured between the tangent to said external profile at the point of intersection with the downstream face and the axis of symmetry of the longitudinal channel, ranging between 5 and 85°. 
     
     
         20 . The device as claimed in  claim 16 , wherein the upstream portion of the longitudinal channel is connected to the downstream portion by one end, said at least one opening emerging into said longitudinal channel at the upstream portion at a distance L z  from the end, wherein distance L z  is greater than or equal to 4% of the length L 3  of the upstream portion. 
     
     
         21 . The device as claimed in  claim 16 , wherein the at least one opening is arranged such that, when the first phase flows from the first inlet of the lateral channel and the second phase flows from the second inlet of the longitudinal channel, the mixing of the first phase and the second phase occurs upstream of the downstream portion. 
     
     
         22 . The device as claimed in  claim 16 , wherein the one or more opening(s) of the mixing device all emerge at the upstream portion of a longitudinal channel. 
     
     
         23 . The device as claimed in  claim 16 , wherein each longitudinal channel of the series of longitudinal channels comprises at least one opening emerging at the upstream portion, with the position of the at least one opening in the longitudinal direction varying between the longitudinal channels. 
     
     
         24 . The device as claimed in  claim 16 , wherein the length L 3  of the upstream portion and the length L 4  of the downstream portion are such that the ratio L 3 /L 4  ranges between 1 and 15. 
     
     
         25 . The device as claimed in  claim 16 , wherein the downstream portion has a depth, measured in a direction, called stacking direction, that is perpendicular to the longitudinal direction and perpendicular to the lateral direction, increasing toward the second outlet. 
     
     
         26 . The device as claimed in  claim 16 , wherein the longitudinal channel comprises at least one obstacle arranged so as to sub-divide the downstream portion into a plurality of intermediate channels emerging at the second outlet wherein said intermediate channels are arranged symmetrically with respect to the axis of symmetry of the longitudinal channel. 
     
     
         27 . A heat exchange facility comprising:
 a heat exchanger comprising a plurality of plates arranged parallel to each other and to a longitudinal direction, said plates being stacked in a spaced-apart manner so as to together define at least a first set of passages configured for a first fluid to flow in the longitudinal direction and at least one second set of passages configured for the flow of a second fluid to be brought into a heat exchange relationship with the first fluid;   a source of a first phase of the first fluid fluidly connected to at least one first manifold of the heat exchanger;   a source of a second phase of the first fluid fluidly connected to at least one second manifold of the heat exchanger;   a mixing device as defined by  claim 16 , said mixing device being arranged in at least one passage of the first series and being configured to distribute the first fluid formed by a mixture of the first phase) and the second phase in said passage of the first series, the first inlet of the lateral channel being in fluid communication with said first manifold, and the second inlet being in fluid communication with the second manifold, the first phase being a liquid phase and the second phase being a gaseous phase.   
     
     
         28 . A method for mixing a first phase and a second phase of a first fluid in a mixing device as defined by  claim 16 , said method comprising the following steps:
 i) introducing the first phase of the first fluid via at least one first inlet of the lateral channel;   ii) introducing the second phase of the first fluid via a second inlet of each longitudinal channel, the second phase flowing in each longitudinal channel in the longitudinal direction to a second outlet of said longitudinal channel;   iii) flowing at least part of the first phase from the lateral channel toward the longitudinal channel via the opening so as to mix the first phase with the second phase in the longitudinal channel;   iv) distributing the mixture of the first phase and the second phase via the second outlet of each longitudinal channel.   
     
     
         29 . The mixing method as claimed in  claim 28 , wherein the first phase is mixed with the second phase upstream of the downstream portion. 
     
     
         30 . A method for liquefying a hydrocarbon stream as the second fluid by exchanging heat with at least one diphasic cooling stream as the first fluid, said method implementing a mixing method as claimed in  claim 28  and comprising the following steps:
 a) introducing the hydrocarbon stream into a second set of passages of a heat exchanger; 
 b) introducing a cooling stream into a third set of passages of the heat exchanger; 
 c) discharging the cooling stream from the heat exchanger and expanding the cooling stream to at least one pressure level so as to produce at least one diphasic cooling stream; 
 d) separating at least part of the diphasic cooling stream originating from step c) into a second phase and a first phase; 
 e) arranging a mixing device in at least one passage of a first set of passages of the heat exchanger; 
 f) introducing at least part of the second phase and at least part of the first phase into the mixing device so as to obtain a first fluid formed by a mixture of the first phase and the second phase at the outlet of the mixing device; 
 g) vaporizing at least part of the first fluid originating from step f) in the passage by exchanging heat with at least the hydrocarbon stream so as to obtain a cooled and/or at least partially liquefied hydrocarbon stream at the outlet of the exchanger.