DE1094718B - Autoclave with high thermal load capacity - Google Patents

Description

GERMAN

The invention relates to an autoclave with a high thermal load capacity, d. H. an autoclave for Execution of processes with high heat throughput.

In the chemical industry it is necessary in some cases to carry out reactions under relatively high levels To carry out pressure rudimentary, and in such cases, as is well known, the so-called Autoclaves. A simple calculation shows that the overpressure is absorbed certain wall of the reaction vessel with increasing pressure and also with increasing vessel volume must always be made thicker so that the pressures that occur can be controlled with certainty can be. For this reason there are certain limits to the dimensions of an autoclave, such as that without serious disadvantages, relatively small vessel dimensions are not exceeded can be. On the other hand, in the interests of labor economy, it would in many cases be advisable to use autoclaves to use the largest possible content.

The difficulties indicated above are exacerbated considerably when processes with high Heat throughput should be carried out, so if the autoclave has a considerable thermal load capacity must be required. The thermal load capacity is to be understood here as the property that relatively large amounts of heat supplied to the reaction vessel or from the reaction vessel in a short time can be removed. The thermal load capacity can also be referred to as thermal maneuverability. This need exists primarily when carrying out reactions that are either are strongly exothermic or strongly endothermic; but also in cases of reactions where this is true does not apply, but at a greatly increased temperature or, if appropriate, a greatly reduced temperature must be carried out, a high thermal load capacity of the autoclave is desirable, because only in In this case, the periods of time required for heating or cooling the autoclave are kept short can. However, long periods of time required for heating up or cooling down affect productivity. because the autoclave is unable to actually carry out the reactions during this time is available.

It is now readily apparent that a correspondingly thick-walled autoclave with a large capacity offers a relatively high resistance to the heat transfer between the outside of the autoclave, which can be easily cooled or heated, and the reaction mixture. Furthermore, the problem is exacerbated by the fact that in such an autoclave, in the event of rapid cooling, autoclave with high thermal
Resilience

Applicant:
CIBA Aktiengesellschaft, Basel (Switzerland)

Representative: Dipl.-Ing. E. Splanemann, patent attorney, Hamburg 36, Neuer Wall 10

Claimed priority:
Switzerland of April 29, 1957

Edgar Jean Mayenfisch, Basel,
and Paul Wipf, Muttenz (Switzerland),
have been named as inventors

or heating up, tensions arise in the vessel wall, which are the result of the internal pressure Superimpose tensile stresses in an unfavorable way. This creates thermal stresses that are in the Material of the reaction vessel as tensile stresses on the inside during heating and during cooling express on the outside. Since, moreover, the reaction vessel is already heavily loaded with increasing pressure is, it follows that such an autoclave under full operating pressure only has a reduced thermal Has resilience. A high thermal load capacity, which is required in some cases, is then only possible with an autoclave of relatively small dimensions.

In principle, the thermal load capacity of the autoclave can thereby be brought to a higher value be that the heat exchange is not carried out through the wall of the autoclave, but accomplished with the help of a snake built into the interior. This can be used as a heating or cooling coil can be used, and in this case the area available for heat exchange can be plentifully measured without difficulty. However, this solution fails in the case of numerous reactions in which a good stirring effect covering the entire contents of the vessel is required is, especially in all those cases where the reaction mixture is relatively viscous or in the In the course of the reaction or where significant amounts of solids are presented during the reaction or arise. Therefore, an autoclave with a substantially smooth inner wall without built-in Heating or cooling coil have significant advantages

009 678/487

in front of an autoclave where this is not the case. In many cases, autoclaves can be built with The cooling or heating coil cannot be used at all.

Known arrangements that serve to introduce stirring and heating devices into the interior of the pressure vessel, result in very complicated constructions.

There are also known autoclaves in which an outer pressure jacket is provided in which the actual reaction vessel is located, whereby the space between jacket and reaction vessel is through a Medium, liquid, gas, etc., which transfers the pressure in the reaction vessel to the jacket is, so that the former can be made thin-walled. It is also known to use the print medium in the To use space for heating or cooling the reaction vessel. In this case it got but still a very large part of the heat to be supplied or removed to the outer pressure jacket, like this that there is still a significant heat gradient in the wall of the pressure vessel. The same applies Arrangements in which the heater is in the pressure jacket itself or between an inner reaction vessel and an outer pressure jacket, so that the pressure jacket is still the thermal Remains exposed to stress.

It is also known, an autoclave from an inner reaction vessel, which is formed by finning with a outer pressure jacket is in communication so that the operating pressure is received by the outer pressure jacket will. The heater is carried by and between the inner reaction vessel Thermal insulation is arranged on the heating device and the outer pressure jacket. The support of the reaction vessel against the pressure jacket is a heat transferring connection, and the heat transferred by this results in particular in the case of rapid and highly exothermic effects Processes an inadmissibly high thermal load on the pressure jacket.

The invention is intended to provide a remedy here. It concerns an autoclave with a high thermal load capacity for carrying out processes under high pressure in a relatively thin inner reaction vessel, wherein the operating pressure is achieved by an external pressure jacket surrounding the reaction vessel is recorded and using the transfer of the pressure from the reaction vessel to the pressure jacket an automatic pressure gas equalization device known per se, characterized in that that the inner reaction vessel is also used to supply or remove heat Device carries and that between the reaction vessel carrying this device and the pressure jacket a continuous, serving for thermal insulation layer is arranged such that no thermally conductive contact occurs between the reaction vessel and the pressure jacket.

The following drawings explain exemplary embodiments of the invention.

1 shows such an autoclave with an insert tank;

FIGS. 2, 4 and 9 show variants of such an autoclave, and FIGS

3, 5, 6, 7 and 8 show structural details of various embodiments.

Fig. 1 shows an autoclave according to the invention. The outer pressure jacket consists of the lower part 1 and the upper part 2. Inside this outer pressure jacket is the relatively thin-walled inner reaction vessel, consisting of the lower part 3 and the cover part 4. The lower part 3 has a welded snake 5 on its outside, for example from a pressure-resistant half-pipe profile. According to the invention, the space between the pressure jacket and the inner reaction vessel is thermally insulated, that is to say, for example, filled with an insulating compound made of ceramic material. The intermediate space between the outer pressure jacket and the inner reaction vessel is connected to a source of pressurized gas via an automatic pressure equalization device in such a way that a pressure approximately corresponding to the reaction pressure is maintained in the intermediate space.
The outer pressure jacket present in the present autoclave can be designed in a manner known per se. Since this pressure jacket does not come into contact with the substances involved in the chemical reaction, it can advantageously be made of a material that is suitable for absorbing high pressures without having to consider the chemical resistance of the pressure jacket. It can therefore be made of cast steel, for example. The insulation between the pressure jacket and the reaction vessel must be designed in such a way that it either transfers the pressure prevailing in the latter to the pressure jacket without deforming the reaction vessel or - in the case of the pressure equalization described below - does not offer any resistance to the equalization of the gas pressure in the space. It is therefore advantageous to use insulation made from Raschig rings, Berl saddles, stoneware balls, etc.

With regard to the heat exchange device located on the inner reaction vessel, it is useful to to connect these firmly to the reaction vessel, e.g. B. in the form of a welded on the outside Cooling coil, e.g. B. in the form of a half pipe. The feeds for the heating or cooling medium that is in the heat exchange device can circulate in any way, expediently with the interposition a certain thermal insulation, can be passed through the pressure jacket. Will the cooling coil Designed to be pressure-resistant, the heating or cooling medium can be supplied from the outside at normal pressure will.

For the operation of the present autoclave is in the space between the outer pressure jacket and maintain a certain pressure in the inner reaction vessel, which is subsequently used as the equilibrium pressure and is supplied from a source of pressurized gas that is independent of the chemical reaction. In the simplest case, this equalization pressure can be supplied by one or more compressed gas cylinders. In many cases it is advisable to use an inert gas, e.g. B. nitrogen to be used. The equalization gas has the important function in the present case, the inner reaction vessel of the to relieve high reaction pressure, which it cannot withstand due to its thin-walled construction could. On the other hand, thanks to its thin-walled construction, the reaction vessel is able to to allow a relatively high heat exchange because of thermal stresses due to its thin-walled construction occur only to a minor extent.

As shown, the pressure in the space between the reaction vessel and the pressure vessel is measured via the line 6 fed to the regulating system. The equalization pressure acts on the regulation via line 7 At the same time, the line 7 is used for the inflow and outflow of the inert gas (z. B. nitrogen).

5 6

In the present case, the regulating system is constantly independent of the pressure jacket 1 and 2.

from two pressure regulators 8 and 9. The pressure regulator 8 is flanged together, this is not in Fig. 2 to 6

connected to the pressure bottles 10, which the more the case.

contain inert gas (preferably nitrogen). In the variant of FIG. 2, there is the use pressure In the gas cylinders there must always be 5 boilers consisting of lower part 53 and upper part 54. The flanges above the maximum operating pressure of the autoclave 153 and 154 of both parts are so wide that they lie between them. To generate the equalization pressure can see the flanges of the two parts 51 and 52 of the compressed air can of course also be used. Will ever- pressure jacket come to rest. The gas line 57 but oil or another organic heating medium for the equalization pressure has both a liquid, such as B. Diphenyl and its derivatives, io circuit in the cover 52 of the pressure jacket and on it used, there would be a certain risk of fire, lower part 51. The line 56 corresponds to the line 6 in case the snake leaks. On the other hand, the Fig. 1. The latter connection can be used with advantage in Steam is used as the heating medium, so press- the stuffing box 59 is laid, air is permitted without further ado. If the internal pressure increases, then FIG. 3 shows a detail of the variant according to Both diaphragms 11 and 12 of the regulator are moved towards the 15 Fig. 2. You can see how the flanges of 53 and 54 are both pressed off. This opens the valve 13, which are processed on the side, so that a good sealing gas flows out of the pressure bottles 10 via the line with the flanges of the pressure jacket 51 and 52 device 7 into the space 14 into it. This will ensure increases. To conduct heat from reacder Equalizing pressure. If, on the other hand, the internal pressure drops, the vessel to the pressure vessel becomes as small as possible so the now greater equalizing pressure presses both 20 hold, the flanges are on the lowest possible wall diaphragm 11 and 12 up. This will reduce the strength and on the inserts 151 and 152 Valve 15 of regulator 9 is open. The gas passes over stored from heat insulating material. Furthermore is the exhaust line 16 to the outside. Two springs 17 and the cooling coil 155 very close to the flange 153 18 ensure that the valves 13 close tightly.

and 15, if on both sides of the membrane 25, FIG. 4 shows a third variant. In this case

Internal and equalization pressure in the desired ratio - the insert boiler consists only of the pressure in the

nis to each other. jacket 71 inserted lower part 73. This can be the

On the line 6 are the safety case, if it is not necessary, the upper part 72 of the valve 19 as well as the control valve 20 and two mano pressure jackets before the attack of the gases of the meter 21 and 22. The control valve 20 allows 30 chemical process. As a result, it is always possible to check whether the line 6 between the simple and the stuffing box 78 is essential. The preparation tank and connection of the valve is clogged or the pressure line 76 is closed still with Vornicht. Furthermore, the manometer 21 can be attached to the cover 72 by comparison. Its connection is considerably simplified in and 22 an additional test of the line 6 during this variant according to FIG. 4, when the control valve 20 opens. On the line 7 there is also a point again advantageously on the stuffing safety valve 23 for the pressure jacket 1 and 2, a sleeve 79 instead. The safety valve 23, the control valve 24 and a pressure gauge 25. The control valve 24 must now be connected to the control valve 24 through the control valve 24 and the smell of this part. In order to determine in this case of flowing gas whether gases from the 40 also reduce the thermal stress to reaction in the cover 72 through a leak in the intermediate area, this can have penetrated on the outside with a space 14. The pressure gauge 25 can be provided with thermal insulation 80, if possible by comparing with 21 a control of FIGS. 5 and 6 show in detail two possible correct functioning of the pressure regulators 8 and 9, the insert tank 73 with the lower part 71 of the further is to be noted that the actuation of the Kon- 45 pressure jacket to seal. In Fig. 5, the flange troll valves 20 and 24 will take place only with caution 76 of 73 again between the flanges of 71 and may, so that the pressure regulation is not falsified or screwed 72, wherein as in Fig. 3, the flange is ineffective. is reduced to the smallest possible wall thickness.

In the present autoclave, the compensating In Fig. 6 is shown a solution in which the

pressure so with the help of a suitable circuit of 50 insert kettles 73 especially on the lower part 71 with the help

Valves are automatically adjusted so that the reac- of screws 75 on a heat-insulating intermediate

pressure corresponds approximately. position 80 is flanged. This solution brings

In some cases it is advantageous to have the advantage that when the cover 72 is lifted off

equal pressure is not changed with the help of the regulation on a little seal between 71 and 73,

higher than the reaction pressure. On 55 Fig. 1 shows a possibility for training

in this way you can avoid, for example, that the stuffing boxes 28 in the event that the insert

If there are any leaks in the boiler, the upper part 4 also has gases from the boiler. With the help of

chemical process into the interspace into the packing 33 and the ring 34 is the seal

and cause corrosion there. the interior of the insert boiler is guaranteed,

The sealing of the shaft 26 of the stirrer 27 is 60 whereby the packing 33 of the rotary movement of the agitator

guaranteed by the stuffing box 28. In Fig. 7 wave 26 allows.

is the detail of such a stuffing box as Bei- Fig. 8 gives an example of the formation of the

game specified. The sealing of the inlet and outlet lower stuffing box 29. With the help of the packing 37

flow of the heat transfer medium (lines 30 and 31) and the ring 38, the seal is carried out,

passes through the stuffing box 29. The space 65 The channels 39, 40 and 41 are in the stuffing box

14 can advantageously be filled with insulating material. the bushings for the equalization pressure line

Fig. 8 shows an example of the stuffing box 29. 57 and the supply line 30 or return line 31 of the

In Fig. 2 to 6 are variants for the formation of the heat carrier.

of the insert boiler. While in Fig. 1 of Fig. 9 shows a further variant of the invention

The upper and lower parts 4 and 3 of the insert kettle are complete. In this case, the insert boiler 103 has one

relatively strong flange 104, which is clamped between the flanges of the lid 102 and the lower part of the boiler 101. This flange 104 is so thick that the lines 106 and 107 for maintaining and regulating the pressure as well as the inlets and outlets 108 and 109 for the heating coils 110 located on the outer wall of the insert can be connected to the outer edge of the flange 104. Accordingly, no bores whatsoever are required in the cover and lower part of the pressure vessel, if one disregards the passage 128 for the shaft of the stirrer 127. The variant shown in FIG. 9 represents an extremely advantageous solution because it not only frees the pressure housing of the autoclave from all thermal stresses associated with heating or cooling the container contents, but also all bores, bushings, etc. which impair the strength of the housing . makes superfluous.

Of course, the variant of FIG. 9 can also be implemented with an inner reaction vessel which has a lower part and an upper part. In this case, the inner upper part is fastened separately on the flange 104. This provides a passage for the pressurized gas both in the lower and in the upper space formed between the inner vessel and the housing.

An autoclave according to the present invention has, inter alia, the advantage that the construction and dimensioning of the outer pressure vessel can only be carried out from the point of view of the Operating pressure and the required size and that no consideration must be given to additional Loads resulting from the heat exchange in the course of the reaction carried out. In particular, processes with a high heat throughput can be carried out without endangering the pressure vessel perform, d. H. those processes in which the temperature in the reaction chamber increases very quickly changes. It is therefore possible, for example, to bring the container to the reaction temperature within a short time bring, which improves the yield significantly, for example with sensitive fabrics. Another advantage is that due to the low thermal inertia, the processes carried out on a large scale dem underlying original laboratory procedures largely in terms of speed the temperature changes can be adjusted. Due to the low thermal inertia of the autoclave there is also a considerable reduction in the unproductive heating and cooling times between the individual batches, so that a much better utilization of the autoclave and thus a The production process is cheaper.

55

Claims (8)

PATENT CLAIMS: 1. Autoclave with high thermal load capacity for carrying out processes under high Pressure in a relatively thin inner reaction vessel, the operating pressure being through an outer pressure jacket surrounding the reaction vessel is received and the transfer the pressure from the reaction vessel on the pressure jacket using an automatic pressurized gas equalization device known per se takes place, characterized in that the inner reaction vessel (3) at the same time the or removal of heat serving device (5) and that between which this device carrying reaction vessel (3) and the pressure jacket (1) a continuous, for thermal insulation serving layer (34) is arranged such that no thermally conductive contact between the reaction vessel and pressure jacket occurs. 2. Autoclave according to claim 1, characterized by a heating or cooling coil (5, 110, 155) firmly connected to the reaction vessel (3) as a heat exchange device. 3. Autoclave according to claim 2, characterized in that the heating or cooling coil (5, 110, 155) is pressure-resistant, so that the heating or coolant can be supplied from the outside at normal pressure. 4. Autoclave according to claim 1, characterized in that the insulating material is gas-permeable and does not offer any substantial resistance to the pressure equalization in the space. 5. Autoclave according to claim 1 and 4, characterized in that the insulation is one as possible large proportion of the volume of the space fills in order to keep the compressed gas consumption to a minimum to reduce. 6. Autoclave according to claim 1, characterized in that the inner reaction vessel has a thick flange (104) which is clamped between the flanges of the upper part (102) and the lower part (101) of the outer pressure jacket and which has a sufficient thickness to to allow the connection of the supply and discharge lines (108, 109) for the pressure equalization between the outer pressure jacket (101) and the reaction vessel (103) and for heating the reaction vessel. 7. Autoclave according to claim 1, characterized in that the inner reaction vessel on all sides is sealed against the outer pressure jacket (Fig. 1 and 2). 8. Autoclave according to claim 1, 2 and 6, characterized in that the inner reaction vessel consists only of a lower part, which together forms the gas-tight intermediate space with the lower part of the pressure jacket (FIGS. 4, 5, 6 and 9). Considered publications:
German Patent Nos. 286136, 388 127, 558, 567 327, 595 306. For this purpose 2 sheets of drawings © 009 678/487 12.60