FR2501520A1 - PROCESS FOR THE TRANSFER OF CONSTITUENTS BETWEEN A LIQUID CURRENT AND A VAPOR CURRENT FLOWING IN AN OPPOSITE DIRECTION, AND SEPARATING PLANT FOR CARRYING OUT SAID METHOD - Google Patents

Abstract

PROCESS FOR THE TRANSFER OF CONSTITUENTS BETWEEN A LIQUID CURRENT AND A VAPOR CURRENT FLOWING IN THE OTHER DIRECTIONS, IN WHICH THE LIQUID FROM THE LIQUID CURRENT IS INTRODUCED BY SPRAYING OR INJECTION IN SUCCESSIVE SECTIONS OF THE VAPOR CURRENT AND IS COLLECTED BETWEEN THESE CURRENTS ; LIKE IN LIQUID JET APPLIANCES, THE LIQUID IS INTRODUCED BY SPRAYING OR INJECTION INTO THE VAPOR CURRENT IN THE DIRECTION OF THE VAPOR CURRENT; THE INSTALLATION USED FOR THIS PURPOSE INCLUDES SEVERAL SEPARATORY STAGES A, B, C, D, E, F, G, H, J, K ALL BEING NEXT TO OTHERS AND SEPARATED BY SENSITIVELY VERTICAL WALLS WHICH ARE FLAT OR CURVED SEVERAL TIMES IN AN ALTERNATE WAY AROUND VERTICAL AXES LIKE A CORRUGATED SHEET.

Description

Method for transferring constituents between a stream

  of liquid and a vapor current flowing in a direction

  milking, and separating installation for implementation

of this process.

  The invention relates to a process for the transfer of constituents between a liquid stream and a reverse-flowing steam stream, in which liquid from the liquid stream is introduced by spraying or injection into successive sections of the vapor stream and is collected between these sections, and it also concerns a separating installation

  for the implementation of this process.

  In a process known from German patent 652, in a corresponding separating installation, the liquid is introduced laterally into the flow of

  vapor and is driven laterally by the downdraft

  fear. As a result, there is a loss of pressure in the vapor stream and the energy consumption is significant. We know, from the article by M. ULLRICH "Der Strahlapparat ais Wascher und Reaktor" from the review "Verfahrenstechnik" volume 14 (1980), NI 12,

  liquid jet (also called jet washers,

  jet voyeurs, jet reactors, jet fans) which,

  so far, however, have only been used for absorption.

  tion as washers or for chemical reactions

as reactors.

  Regardless of this, we know, from Reinhard Billet's book "Industrial Destillation",

  Chemie Editions, from Figure 1.lb and description

  corresponding, an installation for separating a liquid, which contains components having a different boiling temperature, into a bottom product

  with the highest average boiling point

  vee and a top product with a temperature

  lower boiling point and possibly equal

  side fractions, with several separate stages

  teurs. This installation also consumes a lot of energy. The principle of such liquid jet devices is based on the principle of jet pumps described in the

  specification DIN 24 290, April 1974.

  The invention proposes to provide a method of the type mentioned above, in which the energy consumption is relatively low, and a corresponding separating installation which can be carried out

  compactly in the form of a flat construction.

  This problem is solved according to the invention thanks to the fact that, as in liquid jet devices, the liquid is introduced by spraying or injection into the vapor stream in the direction of this vapor stream. The installation for implementing the method according to the invention is characterized in that it comprises separator stages arranged one beside the other

  which are separated from each other by com-

substantially vertical munes.

  In an installation according to the invention, the

  liquid jet separator stages not only do

  there is no loss of pressure or only a very small loss of pressure, but may even (occasionally, depending on the arrangement) cause an increase in

  vapor pressure. In addition, on the separate floors

  liquid jet torers transfer of constituents between

  liquid and vapor is relatively important.

  It is particularly advantageous to maintain a low pressure in the separator stages since then

  the number of separator stages required is lower.

  When low pressure is maintained in the stages

  separators, it is important to keep the value low

  pressure in the steam when crossing the separator stage. On the other hand, due to the very high specific volume of the vapor, when the pressure is low the interior volume of the separator stage must be increased. It is therefore advantageous that the liquid jet separator stages used in the installation according to the invention admit vapor velocities ranging from 5 to 20 m / s and even up to 35 m / s, since therefore the interior volume can be

kept relatively low.

  For a better understanding it will be noted that

  On the pressure loss depend the se-

  parator and therefore the number of separator stages required. The more separating stages, the greater the loss

pressure is important.

  The separating power is all the more important

  that the pressure is low. We therefore need less

  separator stages in the case of low pressure.

  The higher the return rate, the lower the number of separator stages required but

  the more energy consumed.

  To consume as little energy as possible, we take the following measures:

  1 - low pressure in the separator stages for use

  read few separator stages 2 - low pressure loss in the separator stages so as to use only few separator stages; 3 when the first two conditions are met, a relatively low return rate can be used, although this increases the number of separator stages;

  the energy consumption is then however relative-

  low 4 - when low pressure is used, the dimensions depend on the transport speed. Upstairs

  jet separators, we can admit a higher speed

  load-bearing than in current separator stages.

  The installation can be carried out as a flat construction at ground level. All separating floors are therefore accessible from ground level. Consequently, in an installation according to the invention, there is no need for passage walkways comprising expensive emergency exits such as those which are necessary in installations in which are

  dangerous products, or even safety towers

  course or escape with connecting gateways.

  The invention will be better understood using the

  following description of two exemplary embodiments

Z501520

  preferred but not limiting shown in the accompanying drawings in which

  Figure 1 shows schematically a pre-

  first installation; FIG. 2 schematically represents a second installation; and FIG. 3 represents separator stages of particular constitution for the installation of FIG.

1 or Figure 2.

  The installation of figure '1-comprises ten floors

  separators A, B, C, D, E, F, GH, J, K. Each stage separates

  rator has a suction, mixing and separation chamber 4 open upwards on one side 2 and in

  the upper region of which is injected

  teur of liquid 6 directed downwards, and a rise chamber 10 disposed on the other side 8, next to the suction chamber 4, of separation nt mixture and communicating with it, from below. The region of

  lower communication 12 between each room 4 aces-

  piration, mixing and separation and each room

  rise 10 serves as a collecting chamber for the liquid.

  The sides 2, 8 of the suction, mixing and separation chamber 4 are in the form of walls

  14 and 16 respectively, the walls 14 extend

  tending vertically upwards from the bottom 20 and ending before the top 24 leaving a free passage 22, and the walls 16 extending vertically downwards from the top 24 and ending before the

  bottom 20 leaving a free passage 26. The floors indi-

  are connected one after the other by

passages 22.

  The liquid is evacuated from the liquid collecting chamber 12 of each stage by a line 28 in

  which is a pump 30, and is brought to the injector

  6 of the previous floor. The stages E, D, C, B, A constitute a first section of the series of separating stages A to K. To the first separating stage E of this first section are brought, as liquid before

  be sprayed or injected by injectors 6, the li-

  what to separate arriving via line 32 as well as the liquid arriving via line 28 and coming from the liquid collecting chamber 12 of stage F. From the last separator stage A of this first section, the liquid coming from the chamber liquid collector 12 is sent, via a line 34, to an evaporator 36 which separates the liquid into vapor and

  at the bottom of the column. The low-cost product

  lonne is evacuated via line 38. Steam is introduced

  pick up, via line 40, in the lateral passage 22 of the separating stage A. Stage A is the first separating stage of a second section A to K, the stages of which are listed in * reverse direction as the separating stages E, D, C, B, A of the first section, of the series of separating stages, and which in the present preferred case is formed by all the separating stages but overlaps at least the first section E to A. The vapor circulates in the opposite direction of the liquid in all stages A to K and from the last stage K is brought, by a line 42, in which there is a return condenser 44, to a product condenser 46 from which the top product is evacuated by the

  line 48. The return liquid from the line

  return sor 44 is brought, by a pipe 50 into the

  which is a pump 52, on the last stage K to supply the injector 6 which is there, therefore as

than injection fluid.

  In the embodiment of Figure 1, the return condenser 44 is externally cooled by line 54 and the evaporator 36 is heated by

externally by pipeline 56.

  This is deleted in the embodiment of FIG. 2. Here part of the steam leaving the last separator stage K of the second section A to K

  is brought to a heating line 62 in the evapo-

  rator 36, via line 60. The condensate of the condensed steam in the heating line 62 is brought, via line 64, in which there is a pump 66, to the last separator stage K of the second section A to K,

as an injection liquid.

  In line 60 there is, which is not always necessary but nevertheless often advantageous, a steam compressor 68 which compresses the steam in line 60 before it enters the line of

  heating 62. Before entering the separate first floor

  tor E of the first section E to A, the liquid to be separated brought to stage E passes through a preheating pipe in the product condenser 48. This preheating pipe 70 for the liquid simultaneously serves as a cooling pipe for the vapor arriving in the product condenser 48 via line 42. By

  - elsewhere, the installation of FIG. 2 has the same cons-

  titution as the installation of Figure 1, which is underlined by the references identical to those of the

figure 1.

  The separator stages of FIG. 3 respectively comprise mixing chambers 80 which, in a first upper section shrink from top to bottom, then in a second section 84, have a constant cross section, and in a section

  lower 86, flare towards the heap.

  The dividing walls between the individual floors

  installation vials - can be flat or, like corrugated iron, curved around it several times

  vertical axes for the purpose of strengthening.

  It is not necessary that there is only one in-

  - liquid jet in each separating chamber. PIu-

  - several injectors can be placed one below -30 from the other and / or one next to the other, like this

  is described in German patent 2,434,664.

  - - Each climb chamber can contain a separate

  drop separator, preferably a lamella separator

or mesh.

Claims (17)

  1. Process for the transfer of constituents between a stream of liquid and a stream of vapor circulating in   opposite direction, in which liquid from the   rant of liquid is introduced by spraying or injection into successive sections of the vapor stream and is collected between these sections, characterized in that as in liquid jet devices, the liquid is introduced by spraying or injection into the   vapor current in the direction of this vapor current.   2. Method according to claim 1, character-   risé in that the vapor introduced into the vapor stream is produced by evaporation of discharged liquid liquid stream.   3. Method according to claim 2, characterized in that the liquid introduced into the liquid stream is produced by condensation of steam evacuated from the stream steam.   4. Method according to claim 2 or 3, characterized in that the liquid supplied from the outside is introduced by spraying into a central section vapor current.   5. Method according to any one of the claims.   cations 1 to 4, characterized in that the heat of con-   density appearing during the condensation of the   evacuated steam is used to evaporate the evacuated liquid   cué from which the steam introduced is produced.   6. Method according to claim 5, character-   risé in that the evacuated vapor is compressed before the condensation.   7. Process according to any one of the claims.   cations 1 to 6, characterized in that part of the evacuated steam is used for preheating the liquid brought in from outside.   8. Process according to any one of the claims.   cations 1 to 7, characterized in that the steam discharged from the steam stream to the outside is condensed in as a top product.   9. Process according to any one of the claims.   cations 1 to 8, characterized in that the liquid remaining during the evaporation of the liquid to form the supplied vapor is discharged to the outside as a bottom product. 10. Separating installation for placing   work of the process according to one of claims 1 to   9, characterized in that it comprises separate stages   rators (A, B, C, D, E, F, G, H, J, K) arranged next to each other which are separated from each other   others by common walls (14) which are appreciably vertical.   11.-Installation according to claim 10, characterized in that the walls (14) are flat or curved several times, alternately, around   vertical axes, like a corrugated sheet.   12. Installation according to claim 10 or   11, characterized in that each separator stage comprises   carries a suction, mixing and separation chamber   ration (4, 80) open upwards from one side (2), in the upper region of which is arranged at least one liquid injector (6) directed downwards, and a raising chamber (10) arranged the other side (8) of the suction, mixing and separation chamber   (4, 80) and communicating with it from below.   13. Installation according to claim 12, characterized in that the chamber (80) in a first upper section, narrows from top to bottom, then   in a second section (84) presents a cross section constant versal.   14. Installation according to claim 12, characterized in that the chamber (80), in a first upper section narrows from top to bottom, then in a second section (84) has a constant cross section, and in a lower section ( 86), flares down.   15. Installation according to claim 12, characterized in that several injectors (6), located one below the other and / or one next to the other, are arranged in each suction chamber, BM / CP - 1/7/82 - OC 82 04132 - mixing and separation (4, 80).   16. Installation according to any of the   vendications 10 to 15, characterized in that the separating stages (A, B, C, D, E, F, G, H, J, K) are joined by liquid lines in which are located liquid pumps (30).   17. Installation according to claim 12, ca-   characterized in that a droplet separator, preferably a lamella or mesh separator, is housed in the rise chamber (10).