EP1406056A1 - Assembly of an installation for drying moisture loaded material - Google Patents

Abstract

The device has an autoclave that can be heated and evacuated and an evaporator in the autoclave. The goods are heated by the condensation heat of the vapor of a thermal carrier evaporated in the evaporator to extract water from the goods. The evaporator includes a predominantly vertical autoclave wall section heated by the autoclave heating with an arrangement for ensuring heat carrying liquid passes to the wall section as a film. The device has a container (autoclave) (2) for accommodating the drying goods and that can be heated and evacuated with autoclave heating (3) and an evaporator (4) in the autoclave. The goods are heated by the condensation heat of the vapor of a thermal carrier medium evaporated in the evaporator to extract the water in the drying goods. The evaporator includes a predominantly vertical section (18) of an autoclave wall (14) heated by the autoclave heating with an arrangement for ensuring that the heat carrying liquid passes to the wall section as a film. AN Independent claim is also included for the following: (a) system for drying goods containing moisture.

Description

TECHNICAL AREA

The invention is based on an assembly according to the preamble of claim 1. This assembly is part of a system for drying moisture-contaminated goods according to the vapor phase method and has one the heatable and evacuable container (autoclave) that holds the material to be dried as well as an autoclave heater and one arranged in the autoclave Evaporator. With this assembly, the material to be dried is removed by the Heat of condensation of the vapor of a liquid evaporated in the evaporator Heat transfer medium heated. This removes water from the material to be dried. The Dried goods generally contain a hygroscopic electrical Insulating material, for example based on paper or plastic, and is in general as an electrical device, such as a transformer, capacitor or bushing, or executed as part of it. Therefore, the insulating material can be used for drying Formation of a dielectric high-quality insulation with insulating oil or a hardenable Insulating resin are soaked. If the items to be dried have more besides water liquid components, such as high-boiling insulating oil Heat transfer fluid is a solvent that dissolves the components and becomes them Components due to the condensing heat transfer medium from the material to be dried removed. Then not only dry, but also oil-free goods are achieved.

The invention also relates to a module receiving Drying plant.

STATE OF THE ART

With the preamble, the invention takes on a prior art Components for drying systems, as described by P.K.Gmeiner in the Company name of Micafil Vacuum Technology AG, Zurich, MTV / E 02923000/22 "Modern vapor drying processes and plants" is described. One in this script Plant published in diagram S3 for drying moisture-contaminated Good has an assembly with one of the receptacles of the goods to be dried serving autoclave in which a cascade evaporator is installed. This Evaporator contains several cascade-type predominantly vertical heating registers arranged one above the other, via which an easily volatilized and solvent generally designed as a solvent and extractant for oil is stepped from top to bottom. The steam formed is on condensed material to be dried. By the heat of condensation and by a The heating provided in the autoclave heats the goods to a temperature of typically heated to 100 to 130 °. At this temperature and under vacuum water contained in the goods is quickly removed by diffusion and the goods are so quickly dried. A vapor mixture created in this process step of solvent and water is in an outside of the autoclave Capacitor deposited. Is the good as an electrical device, for example as Transformer or bushing, executed, and contains it soaked with insulating oil Electrical insulation, so the solvent can also remove the oil from the insulation extract. The solvent / oil mixture formed in this way collects on Bottom of the autoclave and can during a lowering of the intermediate pressure, i.e. a phase in which the evaporator is no longer supplied with fresh solvent and that Solvent / water vapor mixture from the autoclave into a condenser Drying system is performed, distilled.

PRESENTATION OF THE INVENTION

The invention, as defined in the claims, solves the problem Specify assembly of the type mentioned, which is characterized by a large Usable volume of the autoclave and characterized by simple structure.

In the assembly according to the invention, the evaporator contains one of the Autoclave heating, predominantly vertically oriented section of a Wall of the autoclave, and means are provided on this wall section a guide of the heat transfer fluid in the form of a film on the Ensure wall section. Therefore, the for drying and if necessary in addition, heat transfer fluid vapor required for extracting oil directly on a wall section of the heated by the autoclave heating Autoclaves generated. An additional one independent of the autoclave heating Evaporator heating can therefore be saved. In addition, in the Autoclave wall provided bushings through which the Evaporator heating energy would have to be supplied. Because of the elimination of this additional parts of the evaporator, that is the inclusion of the to be dried The useful volume of the autoclave is particularly large. In addition, the Heat transfer fluid passed over the large wall surfaces of the autoclave and can be extremely effective, d. H. with small difference between temperature of the Wall section and temperature of the heat transfer fluid, in the form of a evaporate thin film. In addition, an assembly according to the status technology in general with little effort, in particular approximately Modification of the autoclave heating, easily in an assembly after the Invention to be converted.

In a particularly advantageous for technical reasons Embodiment of the assembly according to the invention, the autoclave is cuboid executed and has one or more gates. Be included at the same time Wall section a side wall, two or more side walls and / or one or several gates of the autoclave. In this embodiment, the evaporator Particularly easy to maintain because the heating is permanently accessible from the outside and the guide elements for the heat transfer fluid after opening the Autoclaves are easily accessible and extremely easy to maintain, especially can be cleaned.

High evaporation values and a constant evaporation rate over the whole Wall sections are reached when there is a temperature gradient at the wall section can be set with at least two superimposed temperature levels. The Temperature distribution in the wall section is advantageously set so that the Temperature difference on the heat transfer fluid film between the Heat transfer fluid and the wall section each in the area of the two Temperature levels is about the same size. This gradient is particularly simple Way adjustable by two sections of the autoclave heater Sections can be regulated independently of one another. For this, at least one is the Temperature as a controlled variable of the autoclave heating Temperature sensor provided, which is generally on the wall section or on a point of the evaporator is attached, at that of the evaporator Generable vapor of the heat transfer fluid in a moisture-laden Parts containing usable space of the autoclave is feasible.

To supply the heat transfer fluid in a sufficiently good way to the evaporator lead, have the guide means for the heat transfer fluid at the top Distribution system attached to the end of the wall section. Especially then if the distribution system is considered horizontal along the top of the Wall section extending channel with a molded in the channel bottom and run in the channel direction, it is ensured that the Heat transfer fluid evenly out over the heatable wall section and so the desired evaporation with a uniformly thin Surface film is enabled.

Is in the assembly according to the invention on the wall section below the Distribution system arranged at least one horizontally guided storage channel, so a particularly even film in the heatable wall section of the autoclave formed by heat transfer fluid and over the entire surface of the Wall section produces a uniform evaporation rate.

Advantageously, a horizontally extended and is at the lower end of the wall section collecting channel connected to an outlet of the autoclave. A at the drying of the goods, if necessary, accumulating heat transfer fluid / oil mixture then arrives when performing a distillation during a Lowering the intermediate pressure directly to an outlet of the autoclave. It will be so avoided with simple means that the bottom of the autoclave was covered with oil becomes.

It is recommended to have at least one between the distribution system and the collecting trough Arrange the baffle in parallel and at a distance from the wall section. The Steam formed in the heatable wall section is then transferred in the vertical direction passed the entire wall section and can then on one in the baffle molded steam outlet opening at the lower end or through further openings between the upper and lower ends of the baffle in the usable space of the Autoclaves. This results in a usable space in the autoclave turbulent flow of heat transfer fluid vapor. The heat transfer on the material to be dried is improved and the time for heating the Shortened drying goods. By adjusting the opening, the Steam flow and thus the heat transfer can be optimized. The baffle at the same time prevents liquid splashes that occur during evaporation into the Access the autoclave. It is advantageous to have at least one im on the baffle essentially horizontally guided deflection crib attached. About the baffle Splash of heat transfer fluid reappears through this rib the wall section acting as an evaporator heater is returned.

A good heat transfer from the heat transfer medium for high evaporation rates Autoclave heating on the wall section is achieved when the Autoclave heating has at least one channel carrying heat transfer medium, which is bounded by at least part of the wall section.

The autoclave wall is advantageously held by a support structure which Support structure at least in the area of the heatable wall section circulated air is temperature stabilized. Temperature differences in the Support structure are then kept low and thus undesirable stresses in the autoclave wall and the support structure avoided.

DESCRIPTION OF THE DRAWINGS

Fig. 1

in schematischer Ansicht eine Anlage zum Trocknen von feuchtigkeits- und ölbelasteten elektrischen Geräten mit einer Baugruppe nach der Erfindung,

Fig. 2

eine Aufsicht auf einen in vertikaler Richtung geführten Schnitt durch einen Abschnitt einer ersten Ausführungsform der Baugruppe gemäss Fig.1,

Fig. 3

eine Aufsicht auf einen in vertikaler Richtung geführten Schnitt durch einen Abschnitt einer zweiten Ausführungsform der Baugruppe gemäss Fig.1,

Fig. 4

eine Aufsicht auf einen in horizontaler Richtung längs IV - IV geführten Schnitt durch die Baugruppe gemäss Fig.2, und

Fig. 5

eine Aufsicht auf einen analog Fig.4 geführten Schnitt durch eine dritte Ausführungsform der Baugruppe gemäss Fig.1.

The invention is explained below using exemplary embodiments. It shows:

Fig. 1

a schematic view of a plant for drying moisture and oil-contaminated electrical devices with an assembly according to the invention,

Fig. 2

1 shows a plan view of a section in the vertical direction through a section of a first embodiment of the assembly according to FIG. 1,

Fig. 3

2 shows a plan view of a section in the vertical direction through a section of a second embodiment of the assembly according to FIG. 1,

Fig. 4

a plan view of a section in the horizontal direction along IV - IV made through the assembly according to Fig.2, and

Fig. 5

a top view of a section similar to FIG. 4 through a third embodiment of the assembly according to FIG. 1.

WAYS OF CARRYING OUT THE INVENTION

In the figures, the same parts are identified by the same reference numerals. The The system shown in FIG. 1 has an assembly 1 as the central component. This assembly contains a heatable and evacuable container (autoclave 2) a heater 3 and an evaporator 4 arranged in the autoclave Autoclave 2 is essentially cuboid and is not a shown gate with a moisture and oil-containing insulation containing electrical device 5, such as a transformer, loaded. About one Vacuum system 6, the autoclave 2 can be evacuated. From a collecting container 13 which is connected to a reservoir 7 via a pump 8, and / or from a separator 11 can the evaporator 4 via pumps 9 and / or 12th a heat transfer fluid designed as an oil-dissolving solvent can be supplied. Solvent vapor generated in the evaporator 4 with a vacuum applied condenses on Device 5 and heats it by giving off condensation heat. water now diffuses at high speed from the insulation of the device 5. On The solvent / water-vapor mixture formed in this way condenses in an outside of the autoclave 2 located capacitor 10. From the formed here Condensate is removed in the separator 11 and the water remaining solvent via the pump 12 in the reservoir 7 or alternatively in transported the evaporator 4. The solvent condensing on device 5 is extracted the oil contained in the insulation. The resulting solvent / oil mixture collects at the bottom of the autoclave 2 and can be discharged into the Collection container 13 are performed.

In order to accelerate the water outlet during heating in a gentle way, become intermediate pressure drops at comparatively low temperatures performed. With such an intermediate pressure reduction, the supply of Solvent to the evaporator 4 is interrupted and the remaining one Solvent / water-vapor mixture by condensation in the condenser 10 from the Autoclave 2 removed. During this phase of lowering the intermediate pressure, in time-saving way, the solvent / oil mixture with the help of the pump 9 the collecting container 13 transported into the autoclave 2 and distilled. Since here in Evaporator 4 formed solvent vapor by releasing its heat of condensation the device 5 continues to heat up, comes the energy used for the distillation benefits the drying process.

As from the embodiment of the assembly according to FIGS. 2 and 4 can be seen, the autoclave 2 has a vacuum-proof wall 14 and one Wall surrounding heat insulation 15. In the thermal insulation there are pipes 16 trained heating elements of the autoclave heater 3 arranged. The feeding of one in the tubes 16 guided heat transfer medium can be controlled with the aid of a valve 17 become. The tubes 16 are in good thermal contact with a vertical extended section 18 of the wall 14. Such a contact can, for example achieved by welding or soldering the tubes 16 to the wall section 18 become. This wall section is part of the evaporator 4 and carries on the of the Heating 3 facing away means that a guide of the solvent in the form of a ensure thin film on the wall section 18. These funds include a distribution system 19 attached to the upper end of wall section 18, two arranged below the distribution system 19 and against each other vertically offset, horizontally guided storage channels 20, one at the lower end of the Wall section 18 attached, horizontally extended and with a not shown outlet of the autoclave 2 connected collecting channel 21 and a arranged between the distribution system 19 and collecting trough 21 and parallel and baffle 22 guided at a distance from wall section 18. The distribution system is as a channel extending horizontally along the upper end of the wall section 18 191 with one molded into the channel floor and guided in the channel direction Drain gap 192 executed. In the baffle 22 is at the bottom optionally adjustable steam outlet opening 221 is formed. On the baffle three substantially horizontally guided deflection ribs 222 are also attached.

With the reference numerals 23 and 24 are the temperature as a controlled variable Autoclave heating sensors designated, one of which on Wall section 18 and the other attached at one point of the evaporator 4 at which the solvent vapor generated by the evaporator into which the device 5 receiving usable space of the autoclave 2, such as on the Steam outlet opening 221.

When operating a drying system containing this assembly, the Storage tank and / or from the separator 11 pure solvent in the evacuated autoclaves 2 and pumped into the channel 191 of the distribution system 19 fed. In channel 191 the solvent is spread over the entire width of the Wall section 18 distributed and passes through the drain gap 192 to the upper End of the wall section 18. The solvent emerging from the gap flows in the form of a thin film on the wall section 18 downwards. This warms up a temperature which is chosen to be sufficiently high for effective evaporation and essentially constant with the aid of the temperature-controlled valve 17 is held. The storage channels 20 stop the flowing solvent and distribute it it across the full width of the wall section 18. At the bottom adjoining partial surface of the heatable wall section 18 is thus Security again a thin, evenly distributed over the entire area Flow solvent film. The solvent vapor formed on the wall section 18 becomes along the baffle 22 downward and via the steam outlet opening 221 in led the usable space of the autoclave 2. The baffle 22 prevents Solvent splashes get into the usable space. Such splashes are made on the Deflection ribs 222 stopped and flow from these to the storage channels 20. Die Collecting trough 21 ensures that this occurs during the distillation of the solvent-oil mixture oil generated during an interim lowering does not affect the Autoclave bottom, but directly to the oil drain of the autoclave 2.

Since in the described embodiment of the assembly the evaporator 4 in Inside the autoclave 2 is arranged and autoclave and evaporator one Have common heating, this module is characterized by a low energy consumption and at the same time compared to an assembly according to the prior art with one arranged in the autoclave Cascade evaporator usable space gained.

These advantages also characterize the assembly according to FIG. 3. At this However, in contrast to the assembly according to FIG Wall section 18 a temperature gradient with two superimposed Temperature levels can be set. For this purpose, the Autoclave heating in two cascade stages. Heating pipes 16a are arranged in the upper stage and 16a in the lower one second stage heating pipes 16b. The temperature distribution in the wall section 18 can be done by separate control of both stages with the help of control valves and Temperature sensors are set so that one on the solvent film between the solvent and the wall section 18 Temperature difference in the area of the upper stage is approximately as large as in the lower stage. It is then a practically constant evaporation rate across the entire wall section 18 guaranteed. With the reference numeral 25 is one Air circulation marked. Due to the air circulation on the outside of the autoclave 2 lying side of the wall section 18 continuously circulated Air passed along. A supporting the autoclave wall 4 and from Figures 4 and 5 visible structure 28 and the autoclave wall 4 are at least in the Area of the wall section 18 temperature stabilized by the circulated air. Temperature differences in the support structure can be kept as low and undesirable tensions in the autoclave wall and the support structure be avoided.

In a third embodiment of the assembly according to the invention, the Heat transfer medium of the autoclave heater 3 is not guided in tubes 16, but in a flat manner formed channels, one of which is designated by reference numeral 26 marked channel is shown in Fig.5. This channel extends perpendicular to the paper plane predominantly in the vertical direction and points in A small depth in relation to its width. The depth of the channel 26 is determined by unspecified distance means, which predominantly Separate vertically guided part of the wall section 18 from a plate 27. in the Difference to a pipe can now be larger due to the flat profile Amount of heat are released from the heat transfer to the wall section, so that with this embodiment of the assembly a high efficiency and a high evaporation rate can be achieved.

LIST OF REFERENCE NUMBERS

1

module

2

autoclave

3

heater

4

Evaporator

5

Drying goods, device

6

vacuum system

7

storage tank

8, 9

pump

10

capacitor

11

separating device

12

pump

13

Clippings

14

autoclave

15

thermal insulation

16

heating pipes

16a, 16b

Pipes, sections of the heater

17

control valve

18

wall section

19

distribution system

20

storage trays

21

collecting channel

22

baffle

23, 24

temperature sensors

191

channel

192

outflow gap

221

Steam outlet opening

222

deflecting ribs

25

air circulation

26

channel

27

plate

28

support structure

Claims (18)

Assembly (1) for a system for drying moisture-contaminated goods (5) under vacuum with a heatable and evacuable container (autoclave 2) serving to hold the drying goods (5), with an autoclave heater (3) and with one in the autoclave (2 ) arranged evaporator (4), in which assembly (1) the material to be dried (5) can be heated by the heat of condensation of the vapor of a liquid heat carrier volatilized in the evaporator (4) and water can be extracted from the material to be dried (5), characterized in that the evaporator (4) contains a section (18) of a wall (14) of the autoclave (2) that can be heated by the autoclave heater (3), and is predominantly vertically oriented, and that means are provided on the wall section (18) that guide the heat transfer fluid in the form of a Ensure the film on the wall section (18). Assembly according to claim 1, characterized in that the autoclave (1) is cuboid and has one or more gates, and that the wall section (18) comprises a side wall, two or more side walls and / or one or more gates of the autoclave. Module according to claim 1 or 2, characterized in that a temperature gradient with at least two temperature levels lying one above the other can be set on the wall section (18). Module according to claim 3, characterized in that the first and the second temperature stage can each be set by one of two sections (16a, 16b) of the autoclave heater (3), which two sections (16a, 16b) can be regulated independently of one another. Module according to one of Claims 1 to 4, characterized in that at least one temperature sensor (23, 24) which detects the temperature as a controlled variable of the autoclave heater (3) is provided. Module according to claim 5, characterized in that the temperature sensor (23, 24) is attached to the wall section (18) or at a location (221) of the evaporator (4) at which the vapor of the heat transfer fluid which can be generated by the evaporator (4) is in a the drying space (5) accommodating usable space of the autoclave (2) can be guided. Assembly according to one of claims 1 to 6, characterized in that the guide means for the heat transfer fluid have a distribution system (19) attached to the upper end of the wall section (18). Module according to claim 7, characterized in that the distribution system (19) is designed as a channel (191) which extends horizontally along the upper end of the wall section (18) and has a drainage gap (192) which is formed in the channel bottom and guided in the channel direction. Assembly according to one of claims 7 or 8, characterized in that at least one horizontally guided storage channel (20) is arranged on the wall section (18) below the distribution system (19). Assembly according to one of claims 7 to 9, characterized in that at the lower end of the wall section (18) there is a horizontally extending collecting trough (21) connected to an outlet of the autoclave (2). Assembly according to Claim 10, characterized in that at least one guide plate (22) which is guided parallel and at a distance from the wall section (18) is arranged between the distribution system (19) and the collecting trough (21). Assembly according to claim 11, characterized in that at least one steam outlet opening (221) has been molded into the guide plate (22). Assembly according to claim 12, characterized in that the opening (221) is tapped at the lower end or between the upper and lower ends of the guide plate (22). Assembly according to claim 13, characterized in that the opening is adjustable. Assembly according to one of claims 11 to 14, characterized in that at least one essentially horizontally guided deflection rib (222) is attached to the guide plate (22). Assembly according to one of claims 1 to 15, characterized in that the autoclave heater (3) has at least one heat-carrying channel (26) which is delimited by at least part of the wall section (18). Assembly according to one of claims 1 to 16, characterized in that the autoclave wall (4) is held by a support structure (28) which can be temperature-stabilized at least in the region of the wall section (18) by circulating air. Plant for drying moisture-contaminated goods (5) under vacuum with an assembly according to one of claims 1 to 17.

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