PHOSGENE PRODUCTION UNIT

Abstract

A unit for producing and processing phosgene, said unit being configured for at least one maintenance mode and at least one production mode and comprising a structure which defines a confined space in a production mode, said confined space being sub-divided into at least two sub-spaces, wherein (i) at least one sub-space contains at least one apparatus for producing phosgene; (ii) at least one sub-space, other than the at least one sub-space according to (i), contains at least one apparatus for processing phosgene; (iii) the structure comprises at least one openable and lockable access means for temporary access of at least one of the apparatuses according to (i) or (ii) from outside the structure in a maintenance mode.

Claims

1.-15. (canceled)

16. A unit for producing and processing phosgene, said unit being configured for at least one maintenance mode and at least one production mode and comprising a structure which defines a confined space in a production mode, said confined space being sub-divided into at least two sub-spaces, wherein (i) at least one sub-space contains at least one apparatus for producing phosgene; (ii) at least one sub-space, other than the at least one sub-space according to (i), contains at least one apparatus for processing phosgene; (iii) the structure comprises at least one openable and lockable access means for temporary access of at least one of the apparatuses according to (i) or (ii) from outside the structure in a maintenance mode.

17. The unit of claim 16, comprising a phosgene line connecting an apparatus for producing phosgene according to (i) and an apparatus for processing phosgene according to (ii) so that the apparatuses are in fluid communication with each other, wherein the phosgene line is located completely inside the confined space.

18. The unit of claim 16, comprising at least two sub-spaces according to (i); and/or at least two sub-spaces according to (ii).

19. The unit of claim 16, wherein the structure comprises a joint outer housing in which at least one sub-space according to (i) and at least one sub-space according to (ii) are located.

20. The unit of claim 19, wherein adjacent sub-spaces are separated from each other by an inner separation means.

21. The unit of claim 20, wherein the inner separation means comprises at least one inner openable and lockable access means for temporary access of at least one sub-space from at least one other sub-space.

22. The unit of claim 20, wherein the inner separation means comprises at least one inner wall being removably connected to the joint outer housing.

23. The unit of claim 19, wherein the joint outer housing comprises (iv) at least one openable and lockable access means for temporary access of at least one sub-space according to (i); and/or (v) at least one openable and lockable access means for temporary access of at least one sub-space according to (ii).

24. The unit of claim 23, wherein at least one of the openable and lockable access means according to (iv) or (v) is configured as an openable and lockable transfer means for temporary removal, in a maintenance mode, of at least part of at least one apparatus for producing phosgene according to (i) or at least part of at least one apparatus for processing phosgene according to (ii) from the structure through at least one of said transfer means in opened state.

25. The unit of claim 16, wherein the structure comprises (vi) at least one outer housing in which at least one sub-space according to (i) is located, and (vii) at least one outer housing, other than the outer housing according to (vi), in which at least one sub-space according to (ii) is located.

26. The unit of claim 25, wherein at least one of the outer housings according to (vi) and/or at least one of the outer housings according to (vii) lacks a floor and is designed to be movable, preferably liftable.

27. The unit of claim 24, wherein at least one of the outer housings according to (vi) or at least one of the outer housings according to (vii) constitutes a joint outer housing in which at least one sub-space according to (i) and at least one sub-space according to (ii) are located.

28. The unit of claim 16, being comprised in a production plant.

29. A production plant, said production plant comprising a unit according to claim 16.

30. Use of a unit according to claim 16 in a production plant.

Description

[0139] The invention will now be further described by means of example embodiments in view of the figures. The figures show:

[0140] FIG. 1 a first example embodiment of a first type of the invention in a schematic perspective representation.

[0141] FIG. 2 the example embodiment of FIG. 1 in a sectional view taken along plane A-A in FIG. 1.

[0142] FIG. 3 a variation of the first example embodiment in a representation according to FIG. 2.

[0143] FIG. 4 a further variation of the first example embodiment in a representation according to FIG. 3.

[0144] FIG. 5 a second example embodiment of the first type of the invention in a representation according to FIG. 1.

[0145] FIG. 6 the example embodiment of FIG. 5 in a sectional view taken along plane B-B in FIG. 5.

[0146] FIG. 7 a variation of the example embodiment of FIGS. 5 and 6 in a representation according to FIG. 6.

[0147] FIG. 8 the example embodiment of FIG. 7 in a sectional view taken along plane C-C in FIG. 7.

[0148] FIG. 9 a third example embodiment of the first type of the invention in a representation to FIG. 8.

[0149] FIG. 10 a fourth example embodiment of the first type of the invention in a schematic perspective view.

[0150] FIG. 11 a first example embodiment of a second type of the invention in a representation according to FIG. 10.

[0151] FIG. 12 a second example embodiment of the second type of the invention in a representation according to FIG. 11.

[0152] FIG. 13 a sectional view taken along plane D-D in FIG. 12.

[0153] FIG. 14 what is shown in FIG. 13 in a maintenance mode.

[0154] FIG. 15 a third example embodiment of the second type of the invention in a representation according to FIG. 14.

[0155] FIG. 16 what is shown in FIG. 15 in a maintenance mode.

[0156] FIGS. 1 and 2 show a first example embodiment of a first type of an inventive unit. The unit comprises a structure which encloses a confined space when the unit is in a production mode. In this example embodiment the structure comprises a joint outer housing 10, a base onto which the joint outer housing is placed in a gas-tight manner and two outer doors or outer removable panels 12 which close openings of the joint outer housing 10 when the unit is in its production mode. It is to be noted that the base could also form a part of the joint outer housing 10. The outer doors/outer removable panels 12 and the openings closed by them in the production mode constitute openable and lockable access means.

[0157] The confined space is divided into a sub-space according to (i) P and a sub-space according to (ii) S by means of a permanent inner wall 14. The two sub-spaces P, S can independently be accessed via the openings—which are closed by the outer doors/panels 12 in the production mode—when the unit is in a maintenance mode.

[0158] An apparatus for producing phosgene 60 is located in the sub-space according to (i) P and is supplied with carbon monoxide by means of a carbon monoxide supply line 30 and with chlorine by means of a chlorine supply line 31. In order to remove heat from the apparatus for producing phosgene 60, a cooling liquid supply line 32 and a cooling liquid return line 33 are provided. The produced phosgene leaves the apparatus for producing phosgene 60 via a phosgene line 50 which ends at an apparatus for processing phosgene 62. This apparatus for processing phosgene 62 is located in the sub-space according to (ii), so the phosgene line 50 extends from the sub-space according to (i) to the sub-space according to (ii). In the example embodiment shown, the phosgene line 50 extends through the permanent inner wall 14. Closing valves are provided on both sides of the permanent inner wall 14.

[0159] Additionally to the phosgene line 50 a reagent supply line 40 extends to the apparatus for processing phosgene 62 and a product or product mixture in solvent output line 42 extends from the apparatus for processing phosgene 62. So, the phosgene produced inside the confined space is also processed inside the confined space.

[0160] In case of a leakage, phosgene could come into the sub-space according to (i) P or into the sub-space according to (ii) S outside the apparatuses 60, 62 and the phosgene line 50. In order to be able to remove this phosgene, a first exhaust line 46 for the sub-space according to (i) P and a second exhaust line 46 for the sub-space according to (ii) S are provided, such that the sub-spaces can be evacuated from phosgene independently from each another.

[0161] Before the sub-space according to (i) P is opened, the apparatus for producing phosgene 60 and the section of the phosgene line 50 being located in the sub-space according to (i) P must be phosgene-free. For this purpose, a first flushing medium supply line 44 and a first flushing medium return line 45 are provided. In the same manner a second flushing medium supply line 44 and a second flushing medium return line 45 are provided for the apparatus for processing phosgene 62 and the section of the phosgene line 50 located in the subspace according to (ii) S. So it is not necessary to flush the apparatus for processing phosgene 62 when the sub-space according to (i) is opened for maintenance purposes and vice versa.

[0162] FIG. 3 shows a variation to what is shown in FIG. 2. The permanent inner wall 13 shows an opening which is closed by an inner door or panel 18 at least in the production mode. In the case that the complete unit is phosgene-free, the sub-space according to (i) P is accessible via the sub-space according to (ii) S and the sub-space according to (ii) S is accessible via the sub-space according to (i) P, when the door or panel 18 is open or removed from the inner wall 13.

[0163] FIG. 4 shows a variation to what is shown in FIG. 3. Here, the sub-space according to (ii) S is only accessible via the sub-space according to (i) P. This could be a useful setup if the apparatus located in the sub-space according to (i) P needs maintenance more frequently than the apparatus located in the sub-space according to (ii) S.

[0164] FIGS. 5 and 6 show a further variation. Here two sub-spaces according to (ii) S, S′ are provided, each of them comprising an apparatus for processing phosgene 62, 62′. Since both apparatuses for processing phosgene 62, 62′ are provided with phosgene by the same apparatus for producing phosgene 60 being located in the sub-space according to (i), the phosgene line 50 is in a form of a phosgene net. In this example embodiment a part of this phosgene net is located in a supply sub-chamber SU between an intermediate ceiling 20 and the top of the joint outer housing 10. This supply sub-chamber is gas-tightly sealed from the sub-spaces P, S and S′. Since all sub-spaces and the apparatuses being located in them can be made phosgene-free independently from the other sub-spaces as described above, it is for example possible to open the sub-space S′ and perform maintenance work to the apparatus for processing phosgene 62′, while the apparatus for producing phosgene 60 and the apparatus for processing phosgene 62 still work.

[0165] As can be seen from FIG. 7, the concept can of course be generalized to as many sub-spaces as desired. Like it is shown in FIG. 7, it is for example possible to have two sub-spaces according to (i) P, P′, each containing an apparatus for producing phosgene 60, 60′, and two sub-spaces according to (ii) S, S′, each containing an apparatus for processing phosgene 62, 62′. Also in this case, it is preferred to have a phosgene line 50 in form of a phosgene net which connects all apparatuses for producing phosgene 60, 60′ and all apparatuses for processing phosgene 62, 62′. So, an apparatus can be maintained while the other apparatuses still work.

[0166] As it is shown in FIG. 8, a production line often comprises more than one apparatus for processing phosgene for example three such apparatuses 62a, 62b, 62c. Especially in this case it is possible to have more than one production line each being comprised of an apparatus for producing phosgene 60, 60′ and subsequent apparatuses for processing phosgene 62a, 62b, 62c; 62a′, 62b′, 62c′ inside the confined space. For example each apparatus can be located in a separate sub-space. Also in this case it is preferred to connect all apparatuses with a joint phosgene net, so that an apparatus can be by-passed by an identical apparatus in the parallel production line.

[0167] FIG. 9 additionally shows another aspect of the invention. Here, the inner walls 15 are not permanent inner walls but non-permanent inner walls 15 which can be removed, such that the confined space can be configured as needed. In the example embodiment shown, a grid for the non-permanent inner walls 15 is defined by attachment means located on the inside of the joint outer housing 10 and vertically extending posts.

[0168] FIG. 10 shows another example embodiment of an inventive unit having a joint outer housing with two sub-spaces. The difference to the example embodiment shown in FIG. 1 is that one of the sub-spaces is located on top of the other sub-space, such that the permanent inner wall separating the two sub-spaces from one another this extending horizontally.

[0169] FIG. 11 shows an example embodiment of a second type of the inventive unit. The main difference to the first type described above is, that the structure comprises two housings, therein both housings enclose at least one sub-space and therein one housing 11 is movable. This means, that the openable and lockable access means is defined by this movable outer housing 11 itself. In the example embodiment of FIG. 11, this movable outer housing 11 does not have a floor and stands on the roof of a non-movable outer housing which could be in form of a joint housing 10, comprising more than one sub-space, but it is also possible that the lower outer housing contains only one sub-space.

[0170] This concept of having at least one movable housing will become more apparent in view of the example embodiment shown in FIGS. 12 to 14. Here, two movable outer housings 11, 11′ are located on a joint base 17 which also houses a section of the phosgene line 50 which usually means that this base 17 houses a supply sub-space SU. According to the definition chosen here, the base 17 and both movable outer housings 11, 11′ form the structure that defines the confined space. Both movable housings lack a bottom such that in the production mode sections of the base 17 form the lower boundaries of the sub-spaces P, S. The apparatus for producing phosgene 60 and the apparatus for processing phosgene 62 are placed on the base such that they are accessible as soon as the respective movable outer housing 11, 11′ is removed, especially lifted. This is shown in FIG. 14 with the example of the opened sub-space according to (ii) S.

[0171] FIGS. 15 and 16 show a second example embodiment of the second type. Here, the removable outer housing 11 is open at one side and joins the other housing (which is in this case usually not movable) laterally. In a maintenance mode, the removable outer housing 11 is moved to the side.

[0172] Of course, also in the second type of the unit according to the invention, supply lines, cooling liquid lines, flushing medium lines, exhaust lines, reagent supply line(s), and product or product mixture in solvent output line(s) are present, but not shown in the schematic Figures.

[0173] The housings, permanent inner walls, outer doors and inner doors can be made of any suitable material, for example concrete, metal (especially steel or aluminum) or plastic material, especially fiber enforced plastic material, or combinations thereof.

[0174] The non-permanent inner walls and removable panels can also be made of any suitable material, for example aluminum or plastic material, especially fiber enforced plastic material, or combinations thereof.

LIST OF REFERENCE NUMBERS IN THE FIGURES

[0175] 10 joint outer housing [0176] 11, 11′ removable outer housing [0177] 12 outer door/outer removable panel [0178] 14 permanent inner wall [0179] 15 non-permanent inner wall [0180] 17 base [0181] 18 inner door/inner removable panel [0182] 20 intermediate ceiling [0183] 30 carbon monoxide supply line [0184] 31 chlorine supply line [0185] 32 cooling liquid supply line [0186] 33 cooling liquid return line [0187] 34 first flushing medium supply line [0188] 35 first flushing medium return line [0189] 36 first exhaust line [0190] 40 reagent supply line [0191] 42 product or product mixture in solvent output line [0192] 44 second flushing medium supply line [0193] 45 second flushing medium return line [0194] 46 second exhaust line [0195] 50 phosgene line [0196] 60, 60′ apparatus for producing phosgene [0197] 62, 62′ apparatus for processing phosgene [0198] P, P′ sub-space according to (i) [0199] S, S′ sub-space according to (ii) [0200] SU supply sub-space