FR2723322A1 - PROCESS FOR SEPARATING A PRODUCT IN THE STATE OF VAPOR FROM A SUPPORTING GAS - Google Patents

Abstract

In said method, a lift gas (TG) is guided, from top to bottom, transversely with respect to finned tubes (7) internally stressed by a cooling medium (KM), and forming an integral part of bundles (3- 6) finned tubes. A product (P) is then separated in solid form on the finned tubes (7). After the loading of said tubes (7), the supply of lift gas (TG) is interrupted and, in the sequence, the product (P) is separated by melting.

Description

PROCESS FOR SEPARATING A VAPOR PRODUCT,

FROM A SUSTAINING GAS

  The present invention relates to a process for separating

  ration of a product in the vapor state, with a support gas

  tation, process in which the lift gas is guided from top to bottom, transversely with respect to finned tubes which are superimposed in rows and can be internally stressed by a coolant, and the product is then separated under solid shape on finned tubes; in which, after the loading of the finned tubes with the product, the supply of lift gas is interrupted and, in the flow, the finned tubes are internally stressed by a heating agent; and in which the product is separated by fusion with the finned tubes, to be

  then directed to further processing.

  Chemical reaction processes frequently generate organic or non-organic products in the vapor and / or gas state, which are converted either to the liquid phase during cooling, by condensation, or directly to the solid phase with desublimation. . During the extraction of a series of products, for example during the extraction of phthalic anhydride (PSA), the desublimation is applied (partly with

  liquid separation occurring upstream).

  When PSA is extracted, the latter leaves the reac-

  as a component of a lift gas, at times

  peratures between 350 C and 400 C. The heat of reaction

  tion is partly dissipated in the reactor, partly in a gas cooler installed downstream, in which the lift gas is cooled to a temperature above

  the respective sublimation or condensation temperature.

  In the sequence, for the purpose of extraction, the support gas

  tation is allowed in a separator with tubes to

  fins superimposed in rows, which can be interior

  often requested, alternately, by a coolant

  ment and a heating agent. The separator is welded with

gas tightness.

  During the loading phase, the finned tubes are internally stressed by a cooling agent, while the lift gas is generally guided from top to bottom, transversely with respect to said tubes. Under the effect

  coolant flowing through finned tubes

  tes, the PSA is separated from the lift gas and becomes

  pite, in solid form, on the surfaces of said tubes. When-

  that the surfaces of these tubes are loaded with PSA in a way

  such that further separation no longer occurs, or does not occur

  seems more rational, the lift gas supply is interrupted and the finned tubes are internally

  solicited by a heating agent. Following the rise in time

  temperature of the finned tubes, the solid PSA separates before

  feels, by fusion, with the surfaces of said tubes and is re-

  collected, below these tubes, in a collecting compartment

  tor. From there, the PSA is directed to further processing.

  For continuous operation, at least two are used, in general more than three separators among which, alternately, one or more is (are) loaded (s) and another is

  the seat of a separation by fusion.

  The lift gas is cooled to a temperature

  ture between 60 C and 700 C, in order to obtain a high degree

of seperation.

  However, a peculiarity of the lift gas consists in that it contains not only the desired product (PSA), but

  also, in addition, some secondary products which harm

  feels considerably for trouble-free operation and product purity. It has been observed that several of the unwanted by-products are separated, primarily, at this point.

  which is called the "cold end" of the separator ", that is

  say in the finned tubes located downstream in the direction of flow of the lift gas. Guidance of the gas from top to bottom ("down-flow") has proven to be judicious, in practice, in order to be able to maintain an operation largely free of incidents. In fact, in the case of such gas guidance, the secondary products are separated by washing, during each melting process, from the liquid PSA located in the overlying fin tubes. In this case, however, another disadvantage is that the PSA is heavily contaminated with unwanted side products. This is why the process of separation by fusion is directly followed by a distillation generally carried out in two stages. Naturally, this

  the latter is linked to a significant complexity.

  Based on the state of the art, the object of the invention is to provide a process for separating a product in the vapor state from a lift gas, a process in which the product can be extracted in a simple way

  being, for a large percentage, almost free of fouling

  is lying. In accordance with the invention, this object is achieved by the

  due to the fact that during the separation by fusion on the finned tubes

  Your only requests are first of all made by the heating agent.

  fage, the finned tubes which are located downstream in the direction

  tion of circulation of the lift gas and are the last to receive this lift gas, the product adhering to said tubes being separated by fusion, then directed to the subsequent treatment; and by the fact that, at the later stage only, the product also adhering to the other finned tubes is separated by fusion, by internal stress using the heating agent, and is then directed to the subsequent treatment. The peculiarity of this process lies in the fact that the process of separation by fusion takes place almost in two mutually successive phases. Initially, only the finned tubes are used by the heating agent

  located downstream in the direction of flow of the gas above

  temptation, that is to say at the "cold end" of the separator.

  Thus, only the PSA deposited on these finned tubes is also separated by fusion. However, this provides the benefit of

  fusion of secondary products which are preferably generated

  dredges or cause desublimation in this region of the sepa-

  rator (representing around 10% to 40% of the finned tubes used overall). On the other hand, only a very small part

  part of the total quantity of the product is separated in this re-

  separator region. In other words, this means that the process according to the invention makes it possible to extract a large

  amount (i.e. considerably more than 90%) of a pro-

  already clean, which can then be processed by a distiller

  tion in a single phase, with a considerably lower investment and use of energy in comparison with

  the state of the art. If lower requirements are imposed

  the purity of the product, it can even be traded

  specialized without distillation. It remains only necessary to clean the relatively small amount of the dirty product,

  by using a small distillation beforehand

  so that its processing can then

  be followed by a main distillation.

  The process is preferably suitable for desublimation

  phthalic anhydride (PSA) contained by a lift gas

  tion. However, other products may also be ex-

lift gas lines.

  A separator particularly suitable for the process

  die according to the invention has, for example, several features

  fins of finned tubes arranged superimposed and

  with a large number of finned tubes configured in a U shape.

  figuration in U results in a flexible structure having the effect of attenuating thermal shocks. The bundles of finned tubes are connected in series and receive transverse lift gas. This gas is introduced into the separator casing at the upper end of this separator, and leaves said casing at the lower end. The product accumulating below the lowest finned tube bundle is

  withdrawn from the bottom side of the separator.

  Both the coolant and the heating agent

  fage, can be delivered to bundles of finned tubes in

  starting with the extreme lower beam. A body of com-

  mutation, integrated for this purpose in a conduit leading to the beam

  lower extreme, can be connected on the one hand to the rear duct

  the coolant, and on the other hand to the heating agent inlet duct. A corresponding switching device is integrated in a conduit connected to the

  finned tube which is located the highest. This body of com-

  mutation ensures the evacuation, on the one hand, of the heating agent

  fage cooled during the melt separation process and, secondly, the coolant heated during

of the loading process.

  It is also essential that a switching device

  additional be integrated into the conduit located between the lowest finned tube bundle and the overlying bundle. Thanks to the presence of this member, only the extreme lower beam is requested by the heating agent during the first phase of the separation process by fusion. For this purpose, said switching member is controlled in such a way that the heating agent is directly transferred, after having traversed the extreme lower beam, in the discharge duct of this heating agent. Preferably, said

  conduit is also connected to the internal switching member

  in the conduit connected to the extreme upper beam.

  Cooling and melting takes place, in general,

  with coolant oil respectively cold or hot.

  However, it is also possible to use water

cold or even steam.

  It turned out in practice, during loading

  finned tubes, that the product is the subject of a desubli-

  mation in a differently compact form, according to the quantity of the product contained by the lift gas and according to the temperature of the walls of the finned tubes. A high density of loading of the tubes by the product is desirable,

  because this respectively reduces the area required

  to load, or to extend the charging time -

  is lying. There is also a drop in the loss of

gas pressure.

  In this context, in accordance with an improvement

  advantageous, the invention specifically provides that, when charging

  gement, the finned tubes receiving the gas first

  temptation to operate at a higher temperature level

  lower compared to other finned tubes occupying lower positions. This results in an increase in the temperature of the finned tubes near the inlet of the lift gas into the separator. This can be caused by an increased temperature of the coolant and / or a decrease in the amount of the coolant (= lower heat transfer = wall temperature

higher).

  An embodiment of the invention then provides to deliver, to the finned tubes receiving the lift gas first, a quantity of coolant which is lower compared to those delivered to the other finned tubes. In a separator, this can be judiciously concretized, in practice, by the fact that the bundle of finned tubes which is close to the extreme upper bundle and occupies a lower position is directly connected, by means of a bypass, to the duct connected to said extreme upper harness and provided with the switching member

  assigned, respectively, to the evacuation of the heating agent

  fage or coolant. The bypass is then connected, to this conduit, between the extreme upper beam and the switching member. The derivation contains an organ of

  control which can be regulated remotely, and through the

  what can be determined the amount of coolant

  probably not to flow through the upper beam ex-

  very. Another embodiment of the invention, aimed at increasing the temperature level on the bundle of tubes to

  fins located highest, during the charging process-

  consists in that the finned tubes receiving in pre-

  the lift gas are requested, preferably, by

  an intermediate-temperature agent whose temperature level

  ture is higher compared to the coolant

  located in the other finned tubes. In this case, the extreme upper beam is completely excluded from the series connection including the beams occupying lower positions, and it is deliberately solicited, independently, by a particular agent at intermediate temperature whose temperature is at a set level. between that of the cooling agent and that of the heating agent. The agent at

  intermediate temperature can be a heat transfer oil.

  It is possible to integrate for this purpose, in a conduit connected to the bundle of finned tubes located below the

  extreme upper beam, a switching device allows

  both to evacuate the coolant and to

  deflect the heating agent in a corresponding way.

  The heated coolant leaving the finned tube bundles is transferred, via the switching member, into the outlet of this coolant. The post-routing conduit of the heating agent is connected to another switching device which

  authorizes, at the same time, the transfer of the heating agent

  cooled to the extreme upper beam, and the delivery of the intermediate temperature agent to said extreme upper beam. An additional switching device, assigned to the output of the extreme upper beam, ensures the evacuation of

  the heating agent and the medium temperature

  diary. A third possibility, to operate the finned tubes receiving an increased temperature level.

  first the lift gas, during the charging process-

  lies in the fact that these tubes can be advantageously

  internally stressed by a mixture comprising the cooling agent and the heating agent. With this operating mode, a determined quantity of heating agent is derived before the switching member integrated in the conduit leading to the lowest bundle of finned tubes, then it is introduced, via a member

  isolation, in the conduit that connects to each other do

  extreme upper skin and the underlying bundle. In this way, the extreme upper beam is therefore exploited with a mixture comprising the heating agent and the cooling agent.

  When a separator designed for separating

  rage products in the vapor state with a lift gas

  tion, it was also noted that, during the passage of the pro-

  loading stops at the separation process by fusion,

  the whole of said separator is exposed to extra stresses

  usually strong, caused by temperatures, because it is necessary to compensate for temperature differences

  about 130 C to 150 C. According to the invention, for

  significantly reduce the thermal stresses thus caused, and to obtain energy savings, during the alternation of the internal stress of the finned tubes, the latter are preferably internally stressed, from time to time, by a balancing agent whose temperature is between

  temperature of the heating agent and that of the coolant

  coldness. In this case, during a transient phase, at least most of the finned tubes can be supplied with a balancing agent which, due to its thermal balancing, ensures a sharp drop in temperature difference, a reduction in stresses thermal and, consequently, an extension of longevity representing several times the power of ten (Wohler curves). This balancing agent can be a heat transfer oil whose temperature is balanced

Consequently.

  In the operating mode described above, the separation

  rator has, in the conduit leading to the bundle of tubes to

  fins located at the bottom, a switching device which,

  nant a corresponding command, can connect said conduit sometimes to the arrival of the heating agent, sometimes to the arrival of the cooling agent. This switching member can also connect the conduit, connected to the lower harness.

  extreme, to the balancing agent outlet.

  The uppermost finned tube bundle is connected by two conduits to switching devices which

  can connect this extreme upper beam to the exhaust duct

  cuation of the cooled heating agent, to the inlet pipe of the balancing agent and to the outlet pipe of this balancing agent. One of these switching devices is also able to connect the inlet pipe of the cooled balancing agent, by means of an intermediate pipe, to

  a switching device which is integrated in a conduit

  connecting, to the coolant discharge duct, the bundle of finned tubes located below the extreme upper bundle. This conduit conveying the balancing agent also has the effect of transferring the heating agent into

  the extreme upper beam, from the beam located above

  below this extreme upper beam and, from said extreme upper beam, into the discharge duct of

the heating agent cooled.

  Whether to pass the process separator

  loading in the fusion separation process,

  first of all, in order to reduce the difference in temperature

  erasures between the cooling agent and the heating agent

  ge, an intermediate phase during which the fin tubes

  your are requested by the balancing agent presenting a

  higher temperature compared to coolant

  so that the finned tubes and the housing take

  a higher temperature which reduces the thermal stresses

  that when said tubes are stressed, in the chain-

ment, by the heating agent.

  The different procedures described above per-

  set (as is so far conventional) to guide both the cooling agent and the heating agent from bottom to top, through the bundles of finned tubes, against the current with respect to the lift gas . That is

  however linked to the property consisting in that, during the

  wise from the separator from the loading process to the fusion separation process, a relatively hot heating agent

  whose temperature is about 180 C to 200 C comes to meet

  trer, at the entry of the lowest finned bundle of finned tubes, the material having a temperature of about 55 C, which, especially in this region of the separator, involves

  very high thermal stresses.

  To avoid these constraints, the invention provides that the heating agent is directed from top to bottom by

  at least part of the finned tubes, and that the

  cooling is directed from bottom to top by these fin tubes

  your. Thus, in this operating mode, the heating agent comes

  encounter a material that has already taken a higher temperature

  because the coolant has warmed up by approx.

  ron 15 C on its path between the extreme lower beam and the extreme upper beam. In this way, it is possible to achieve a decrease in the temperature difference of about 10% to 12%. In the presence of alternate requests,

  this results in a longevity of the separator which is sensitive-

doubled.

  According to one embodiment, this operating mode can be put into practice by the fact that the bundles of finned tubes of the separator are connected in mutual succession, and that only the inlet conduit winning the lower beam

  end and the exhaust duct from the upper beam

  extreme laughter contain switching devices which

  hand, on the extreme lower beam, allow alternati-

  The arrival of the cooling agent and the evacuation of the heating agent and, on the upper upper beam, the evacuation of the cooling agent and the arrival of

the heating agent.

  If, on the other hand, a separation by fusion is carried out

  fractional, i.e. a process operating in two phases

  its first involving a separation by fusion on the bundle of finned tubes located at the bottom, we prefer an arrangement in which a switching member, connected to the inlet conduits of the coolant and the heating agent, is integrated into the inlet duct leading

  said extreme lower beam. The duct winning the exterior

  laughing, from the most centrally located fin tube bundle

  top, contains a switching device which authorizes the evacua-

  the coolant and the arrival of the coolant

  heating said extreme upper beam. A commu-

  tation, integrated in the conduit bringing the heating agent, makes it possible to direct this heating agent adequately towards the switching member which is integrated in the conduit connected to the extreme upper beam. It also authorizes, if necessary

  is, the delivery of the heating agent to the commu-

  tation which is integrated in the duct leading, from the outside, to the extreme lower beam. In addition, we have integrated

  conduit located between the extreme lower beam and the

  overlying skin, a switching device which, on the one hand, authorizes the post-routing of the cooling agent to the overlying beams, and which, on the other hand, during the first phase of separation by fusion, guarantees the heating agent directed only through the bundle

lower extreme.

  Of course, the scope of the invention also includes the idea that the lift gas travels from bottom to top of the housing of a separator, the bundles of finned tubes extending horizontally as before. This operating mode of a separator also implies, in a way

  corresponding, an inversion of the solicitations of the

  tubing by the heating agent, the cooling agent

  The balancing agent and the inter-

  medial. The invention will now be described in more detail, by way of non-limiting examples, with reference to the appended drawings in which FIGS. 1 to 7 are representations

  schematics of separators according to the invention.

  FIGS. 1 to 7 illustrate separators 1, la-lf intended for separating a product (P), consisting of phthalic anhydride (PSA), from a lift gas TG. Several bundles 3, 4, 5, 6 of finned tubes are superimposed in four stages in a casing 2 of the separators 1, la-lf. Finned tubes 7 of said bundles 3-6 all have a U-shaped configuration and are respectively connected, by their two ends, to two compartments A, B separated from one another. The lift gas TG enters the casing 2 at the upper end of the latter, via a

  sleeve 8, it circulates all around the tubes 7 with conformed fins

  even to the STR arrows, transversely from top to bottom, then

  leaves the casing 2 at the lower end thereof, by the

through a sleeve 9.

  The reference numeral 10 designates a withdrawal sleeve.

  age of product P extracted from the lift gas TG.

  In the embodiment of the separator 1 of FIG. 1, a conduit 11, in which a switching member 12 is integrated, is connected to compartment A of the bundle 3 of finned tubes located at the bottom. Respective ducts 13, 14

  of an HM heating agent and a cooling agent

  KM are connected to switching device 12.

  A conduit 15, connected to compartment B connected to the beam

  ceau 3 of finned tubes, is connected to compartment A of the bundle 4 of finned tubes which is adjacent to said lowest bundle 3. A switching member 16 is integrated in

  the conduit 15. A conduit 17 for evacuating the heating agent

  ge HM cooled is also connected to line 15.

  Furthermore, FIG. 1 shows that compartment B of the bundle 4 of finned tubes is connected, via a conduit 18, to compartment A of the bundle 5 of finned tubes, and that compartment B of said bundle 5 is connected, via a conduit 19, to compartment A of the bundle 6

  of finned tubes which is located the highest.

  A conduit 20, in which a switching member 21 is integrated, is connected to compartment B of the bundle 6 of finned tubes located at the top. A pipe 22 for discharging the heated KM coolant and the pipe 17 for discharging the cooled HM heating agent are, in

  in addition, connected to this switching member 21.

  During the loading process, the control of the switching member 12 housed in the duct 11 is reversed so that, via compartment A, the bundle 3 of finned tubes is connected to the inlet duct 14 KM coolant. The switching member 16, housed in the conduit 15 located between the compartments B and A of the

  bundles 3 and 4 of finned tubes, is switched so as to

  put the KM coolant drain. The connection is closed in the direction of the evacuation pipe 17 from

  the HM heating agent cooled. In addition, the switching member 21 integrated in the conduit 20 is switched to authorize

  the flow of the warmed KM coolant. The

  connection to the exhaust duct 17 is broken.

  The lift gas TG is now introduced into the

  casing 2. Under the effect of the KM coolant circu-

  In the finned tubes 7, the product P separates on the

  external surfaces with fins of said tubes 7. The gas of

  temptation TG cleared of product P is evacuated through

  diary of the sleeve 9. The sleeve 10 for withdrawing the product P is closed.

  When the finned tubes 7 are sufficiently charged

  aged, the inflow of the lift gas TG towards the casing 2 is interrupted. In addition, the switching member 21 housed in the conduit 20 is controlled in an isolation position. The switching member 16 integrated in the duct 15 is tilted to a position in which the bundle 3 of finned tubes which is located the lowest is connected to the duct 17 for discharging the heating agent HM. The control of the switching member 12 housed in the conduit 11 is reversed so that, from now on, the conduit 11 is connected to the inlet conduit 13 of

the heating agent HM.

  Now, the HM heating agent is admitted, which reaches the exhaust duct 17 in

* traversing the switching member 12, the conduit 11, doing it

  3 of finned tubes, the duct 15 and the switching member

  tion 16. The heavily fouled product P, deposited on the lowest bundle 3, is thus separated by fusion to be

  then withdrawn via the sleeve 10.

  After separation by fusion taking place in the

  3 of the finned tubes which is located the lowest, we invert-

  is the control of the switching member 16 integrated in the conduit 15, so that said beam 3 is now connected to the

  conduit 20 via all the above beams

  underlying 4, 5 and 6 of finned tubes. In addition, the

  mutation 21 housed in the conduit 20 is tilted to allow the flow of the cooled HM heating agent, so that said conduit 20 is now connected to the evacuation conduit 17. In the sequence, by biasing the with the aid of the heating agent HM, the relatively clean product P is also separated, by fusion, from all the other bundles 4-6 of finned tubes, then withdrawn via the

sleeve 10.

  Thanks to a corresponding order reversal of the or-

  switch gears 12 and 21, the separator can then be cooled again and released again for the process of

loading.

  The variant of a separator la, illustrated in the figure

  2, differs from that of FIG. 1 by the fact that the con-

  duit 19, interposed between the uppermost bundle of finned tubes 6 and the underlying bundle 5 of finned tubes, is short-circuited by a branch 23 in which is

  integrated a remote-controllable control member 24. Com-

  part B of bundle 5 is therefore connected, via the

  middle of the bypass 23, to the conduit 20 which connects the compar-

  beam B of the extreme upper bundle 6 to the conduits 17 and 22 discharging, respectively, the cooled heating agent HM and

  KM coolant warmed up. In this way, by the in-

  bypass 23, part of the reductive agent

  KM cooling can be directed to the evacuation duct 22

  tion of this warmed KM agent, hence an increase in the temperature

  temperature of the tubes 7 with fins present in the bundle 6, because of the lesser quantity of cooling agent KM which circulates by this bundle 6 located at the highest. The product P can thus be deposited in a more compact form on said bundle 6. Of course, in the embodiment of FIG. 2, it is also possible to connect the two bundles 3, 4

  finned tubes located at the bottom, as explained

  qué above, in support of figure 1, for an operation in

two phases.

  For the rest, the separator la in Figure 2 works

  in the same way as that of figure 1.

  The separator lb of the embodiment of Figure 3 also allows an increase in the temperature level

  the uppermost bundle of finned tubes 6, in order to

  hold a high loading density, at least of said bundle 6, with the product P. For this purpose, the bundle 6 of finned tubes located highest can be requested by a ZM agent at temperature

  intermediate, whose temperature can be balanced inde-

  pending KM coolant. To this end, a conduit 25 connected to compartment A of said bundle 6 contains a switching member 27 which authorizes the biasing of the tubes 7 with fins of said bundle 6 by the agent ZM at intermediate temperature. This switching member 27 also serves to

  transfer, in bundle 6, the HM cooling agent

  di coming out of the bundle 5 of finned tubes, located below the extreme upper bundle 6. The switching member 27 is

  connected for this purpose, via a conduit 30, 28, to the

  part B of the beam 5. An integrated switching member 29

  in this conduit 30, 28 allows, by means of an operating position

  corresponding operation, to transfer the coolant

  KM heated in exhaust 22.

  The cooled HM heating medium leaving the compartment

  ment B of the uppermost finned tube bundle 6, or respectively the intermediate temperature agent ZM, is

  (are) delivered to a switching device 31 via

  diary of a conduit 26. A corresponding connection makes it possible to evacuate, respectively via the conduit 17 or a conduit 32, the cooled HM heating agent and the ZM agent

at intermediate temperature.

  Thus, during the loading process, the bundle 6 of finned tubes is requested by the agent ZM at temperature.

  intermediate by means of the switching member 27 and the con-

  duit 25, as well as compartment A. The temperature of this agent ZM is at a higher level than that of the cooling agent KM which, during the loading process, is transferred from the conduit 14 to the conduit 22 by traversing the switching member 12, conduit 11, bundles 3-5 of tubes to

  fins, the conduit 28 and the switching member 29.

  With a view to separation, by fusion, of the product P deposited

  on the finned tubes 7 of the bundles 3-6, the control of the or-

  switching gans 12, 29, 27 and 31 is reversed so

  that, from now on, the heating agent HM is transferred from the

  inlet line 13 to the duct 17 for discharging said heating agent HM, now heated, by traversing the switching member 12, the duct 11, the bundles 3-5, the duct 28, the switching member 29, the conduit 30 interposed between the switching members 29 and 27, the conduit 25, the harness 6, the

  conduit 26 and the switching member 31.

  Regarding the process of separation by fusion in the

  bundle 3 of finned tubes located the lowest, it is also

  It is possible to use, if necessary, instead of the operating mode described above, the variant of connection to

two phases according to Figure 1.

  FIG. 4 represents a separator lc in which it is similarly possible to increase, during the loading process, the temperature of the tubes 7 with fins of the bundle 6

  located the highest. A conduit 33 in which an isolating organ

  ment 34 is integrated is connected, for this purpose, to conduit 19 if-

  killed between said bundle 6 and the underlying bundle 5 of tubes

  with fins, and it is on the other hand connected to the duct 13 of ar-

  shunt from the HM heating medium to the switching device

12.

  If it is therefore necessary during the charging process to more strongly balance the temperature of the

  tubes 7 with fins of the bundle 6 located the highest, an opening

  corresponding ture of the isolation member 34 makes it possible to add

  ter, to the coolant KM circulating towards said beam

  skin 6 from bundle 5 of finned tubes, a quantity

  HM heating agent.

  Otherwise, the operation of the lc separator can

  be carried out in the same way as that of separator 1 of the

gure 1.

  The embodiment of FIG. 4 can also

  be fitted with a connection variant allowing compliance

  even in figure 1, during the process of separation by fu-

  sion, a separation by fusion taking place first, in a

  first phase, only in bundle 3 of finned tubes -

  tes located lowest, with a product P heavily fouled, and then only in the overlying bundles 4-6 charges

of a relatively clean product P.

  The embodiment of the separator ld according to FIG. 5 makes it possible, during the loading process, to urge the bundle 6 of finned tubes, located the highest, by a balancing agent AM whose temperature is higher than that of

  the coolant KM. A conduit 35 connected to the compartment

  ment B of said bundle 6 contains, for this purpose, a

  mutation 37 which ensures, through a position of function-

  corresponding operation, that the balancing agent AM is directed, via an inlet conduit 38, a switching member 39, a conduit 36, compartment A, the bundle 6, the conduit 35 and switching member 37, to

  a conduit 40 for evacuating this agent AM.

  Another connection variant consists in directing the balancing agent AM coming from the inlet duct 38, via the switching member 39 and a junction duct 41, towards an integrated switching member 42 in the coolant evacuation duct 22 KM, which is connected to compartment B of the bundle 5 of finned tubes located below the bundle 6 of finned tubes occupying the highest position. The beams 3-5 situated below the extreme upper beam 6 can thus, too,

  be requested by the AM balancing agent. After leaving

  ran the beams 5, 4 and 3, this AM agent comes to his con-

  evacuation duit 40 via a communication member

  tation 43. This switching member 43 is integrated in the duct 11 leading to compartment A of the lower extreme bundle 3. The switching member 43 integrated in the conduit 11,

  the switching member 37 integrated in the duct 35 and the organ-

  switching element 42 integrated in the exhaust duct 22 can also be controlled in such a way that the heating agent HM is transferred from the inlet duct 13 to the exhaust duct 17 by traversing the bundles 3-5 of finned tubes, the switching member 42, the conduit 41, the member

  switch 39, conduit 36, upper beam 6 extremely

  me, the conduit 35 and the switching member 37.

  During the loading process, in addition to the solicitation-

  tion of the extreme upper beam 6 by the balancing agent

  AM, the underlying beams 3-5 can also be sol-

  allowed from the coolant agent conduit 14

  dissement KM, via the switching device 43. The heated KM coolant, coming from the bundles 3-5, arrives in the discharge duct 22 via the switching device 42 controlled Consequently. FIG. 6 illustrates a separator le in which the heating agent HM and the cooling agent KM are

  directed, respectively, from top to bottom and from bottom to top through

  to 3-6 bundles of finned tubes. A commu-

  tation 44, integrated for this purpose in the duct 11 connected to compartment A of the bundle 3 located at the bottom, connects said

  compartment A either at conduit 14 of arrival of the recovery agent

  KM cooling, sometimes to the duct 17 for discharging the cooled HM heating agent. Correspondingly, the conduit 20 connected to compartment B of the bundle 6 of finned tubes located most

  top contains a switching member 45 which allows either

  set the HM heating agent towards harnesses 6-3, from

  of the inlet duct 13, or to transfer the coolant

  KM pipe heated up to its exhaust pipe 22.

  The variant of Figure 6 can similarly be used.

  performed in a two-phase fusion separation involving a staggered fusion separation taking place, first, in the lower bundle 3 of finned tubes, then, with time shift, in the overlying beams 4-6 of tubes

  with fins (connection variant of Figure 1).

  FIG. 7 illustrates a separator lf in which a re-

  intermediate heating is provided, initially, also

  When switching from the charging process to the pro-

separation from merger.

  A conduit 11, in which a switching member 12

  is integrated, is for this purpose connected to compartment A of the

  3 of the finest tubes located at the bottom. The commu-

  tation 12 is connected, on the one hand, to the conduit 14 of arrival of the coolant KM and, on the other hand, to a conduit 46

  branching off from the inlet pipe 13 of the heating agent HM.

  The duct 15, connecting compartment B of the extreme lower bundle 3 to compartment A of the overlying bundle 4, is provided with a switching member 16 to which is moreover connected

  the pipe 17 for discharging the cooled HM heating agent.

  The compartment B of the bundle 4 of finned tubes is connected,

  via a conduit 18, to compartment A of the beam

  overlying skin 5, compartment B of this bundle 5 being connected, via a conduit 19, to compartment A of

beam 6 upper extreme.

  A switching member 45, integrated in the conduit 20 connected to compartment B of the bundle 6 of finned tubes located at the top, is connected on the one hand to a conduit 47 branching off from the conduit 13 of arrival of the heating agent HM and, on the other hand, to the duct 22 for discharging the heated KM coolant. HM inlet pipe 13

  also contains a switching device 48, via

  re from which the heating agent HM can be transferred to the switching member 12 housed in the duct 11 and / or to the

  switching 45 housed in conduit 20.

  During the loading process, the coolant

  KM flow from the inlet duct 14 is directed from bottom to top towards the exhaust duct 22 against the current with respect to the lift gas TG, by means of a corresponding control reversal of the switching member 12, by l intermediary of this member 12, bundles 3-6 of finned tubes, of the duct 20 and of the switching member 45. To this end, the switching member 16 integrated in the duct 15

  is tilted to allow coolant to flow

dissement KM.

  If the process of separation by fusion is initiated at

  the completion of the loading process, the order of the organ-

  switching circuit 12 is first of all reversed so that the conduit 11, leading to compartment A of the bundle 3 of

  lowest tubes & fins, now connected to the con-

  duit 46 of bifurcation of the heating agent HM. The switching device 48 integrated in the agent inlet conduit 13

  HM heater is tilted so that said heater

  ge HM can flow, in the extreme lower beam 3, uni-

  only through the bifurcation conduit 46 and

  the switching device 12. The switching device 16, integrated

  in the conduit 15 located between the compartment B of the bundle

  3 lower extreme and compartment A of bundle 4 above-

  jacent, is also connected in such a way that the connection between compartment B and compartment A is closed, but that compartment B is in return connected to conduit 17

  of the cooled HM heating agent.

  In this way, a separation by fusion can first take place in the bundle 3 of finned tubes located at the bottom, with a product P strongly fouled. This product P separated by fusion is then withdrawn via the sleeve

placed on the bottom side.

  After separation, by fusion, of the dirty product P from the bundle 3 of finned tubes located at the bottom,

  the switching member 48, integrated in the duct 13 at the rear

  of the heating agent HM, is now switched so

  that the heating agent HM is directed at the same time to the

  3 lower extreme, through the bi-

  furcation 46, of the switching member 12 and of the conduit 11,

  and, via the bifurcation conduit 47 and the or-

  switching gane 45, the control of which is therefore reversed

  quence in the conduit 20, towards the extreme upper bundle 6 then, from the latter, via the successive beams and 4, to the switching member 16 on which it is then transferred into the conduit 17 d evacuation of

  the HM heating agent cooled. In this way, the product P re-

  laterally pure is also separated by fusion with the

  6-4 tails of finned tubes, then is withdrawn through

sleeve diary 10.

  It goes without saying that many modifications can be made to the process described and shown, without departing from the

part of the invention.

Claims (7)

-R E V E N D I C A T I ONS-   1. Process for the separation of a product (P) in the state of   fear, with a lift gas (TG), a process in which the   lift gas (TG) is guided from top to bottom, transverse-   with respect to tubes (7) with fins which are superimposed in rows and can be internally stressed by a   coolant (KM), and the product (P) is then dried   adorned in solid form on the finned tubes (7); in the-   which, after loading the finned tubes (7) by the pro-   duit (P), the lift gas supply (TG) is interrupted   and, in the sequence, the tubes (7) with fins are integrated   laughed at by a heating agent (HM); and in which the product (P) is separated by fusion from the tubes (7)   with fins, to then be directed to further treatment   laughing, process characterized in that, during the separation   tion by fusion on the finned tubes (7), only the heating agent (HM), the tubes are first of all   (7) with fins which are located downstream in the direction of   citation (STR) of the lift gas (TG) and are the last to receive this lift gas (TG), the product (P) adhering   to said tubes being separated by fusion, then directed to the process   later; and by the fact that at the later stage uni-   cally, the product (P) also adhering to the other tubes (7) with fins is separated by fusion, by internal stress using the heating agent (HM), and is then directed towards further processing.   2. Method according to claim 1, characterized in that, during loading, the tubes (7) with fins receiving first the lift gas (TG) are operated at a higher temperature level compared to the others finned tubes (7).   3. Method according to claim 2, characterized in that, compared to the other tubes (7) with fins, only a partial quantity of the cooling agent (KM) is supplied to the tubes (7) with fins receiving first the gas lift (TG).   4. Method according to claim 2, characterized in that the tubes (7) with fins receiving the gas first   lift (TG) are solicited by a temporary agent (ZM)   intermediate ture, whose temperature level is higher compared to the coolant (KM) located in the other finned tubes (7).   5. Method according to claim 2, characterized in that the tubes (7) with fins receiving the gas first   lift (TG) are solicited, internally, by a   diaper including the coolant (KM) and the coolant heating (HM).   6. Method according to any one of claims 1 to   , characterized in that, during the alternation of the internal stress of the finned tubes (7), the latter are internally stressed, from time to time, by an agent   balancing (AM) whose temperature is between the   of the heating agent (HM) and of the heating agent cold (KM).   7. Method according to any one of claims 1 to   6, characterized in that the heating agent (HM) is directed from top to bottom by at least part of the tubes (7) with fins, the cooling agent (KM) being directed from below   at the top by these finned tubes (7).