EP2148157B1 - Device for heating and drying a good according to the vapour-phase method - Google Patents

Description

The invention is based on a device for drying a product, in particular of solid insulation of an electrical device, according to the preamble of patent claim 1.

In this device, the heat of condensation of a solvent vapor generated in a steam generator for rapid and gentle heating of the material is utilized. The material to be dried generally comprises the solid insulation of an electrical device, such as a power transformer, especially so-called "shell type" transformers having disc windings which are separated by insulation plates. The device or at least its active part containing the solid-state isolations are arranged in a vacuum container, for example an autoclave, held under reduced pressure. When heating from the solid insulating water leaking water is supplied in the form of a solvent and steam containing mixed steam together with unavoidable leakage of a condensation and separation device in which the condensed water separated from the solvent and the leakage air is sucked with a vacuum pump. Optionally present insulating oil and / or impurities are removed by distillation from the solvent.

• Aufheizen des beladenen Autoklaven mit kondensierendem Solventdampf und gegebenenfalls zusätzlich mit der Autoklavheizung, um den überwiegenden Teil des Wasser sowie des gegebenenfalls vorhandenen Isolieröls und der Verunreinigungen aus dem Gut zu entfernen,
• Durchführen von Zwischendrucksenkungen im Autoklaven, um während des Aufheizens ausgewaschenes Isolieröl abzudestillieren und um in besonders schneller und schonender Weise die vorgenannten Substanzen zu entfernen,

The device is used in the following phases of the vapor phase method.

• Heating the loaded autoclave with condensing solvent vapor and possibly also with the autoclave heater, in order to remove most of the water and the optionally existing insulating oil and impurities from the estate,
• Carrying out intermediate pressure reductions in the autoclave in order to distil off washed-out insulating oil during the heating and to remove the abovementioned substances in a particularly rapid and gentle manner,

State of the art

A device of the type mentioned is DE 30 14 831 A or EP1528342B1 removable. A described in this prior art, working by the Vapor phase method drying device for insulating oil-impregnated insulation has a the insulators to be dried receiving evacuated autoclave, in which a cascade evaporator or a vapor jet evaporator is arranged. The cascade evaporator is oriented substantially vertically and includes a flow channel defined by a plate and a partition wall. On the plate heating coils and baffles are arranged. The cascade evaporator is fed by means of a pump solvent, which was heated in a preheater located outside the autoclave. The preheated solvent trickles with the cooperation of the baffles along the plate from top to bottom. Here, the solvent evaporates on the heating coils. The forming solvent vapor flows vertically upward due to the chimney effect in the flow channel and is conducted via a steam inlet into the usable space of the autoclave containing the insulations.
In the Vapor Jet evaporator hot solvent is injected at high speed at the narrowest point into a Venturi channel, while largely evaporated and entrained as a result of the jet effect large amounts of existing in the autoclave solvent vapor.

Another by the Vapor Phase method operated drying device was applied in the US by the companies "General Electric" and "Westinghouse" from about 1960. The solvent was heated in a solvent heater outside of an autoclave and introduced into the vacuum autoclave and thereby evaporated, as in
Book " A Guide to Transformer Maintenance "by SDMeyers, JJ Kelly, PHParish, p. 496 (Transformer Maintenance Institute, Division, SDMyers, Inc. Akron Ohio, 1981 ) mentioned. In this case, the solvent is heated substantially above the drying temperature, since the solvent evaporation heat is removed from the solvent, it cools down. An accurate temperature control of the solvent vapor is difficult, since various factors such as pressure and temperature in the autoclave affect the evaporation rate and thus also the solvent temperature.

The aforementioned device of the type mentioned is also described in US 2002/0184784 A1 , In this prior art, heating fluid is heated in the liquid phase leaving outside a vacuum vessel containing dry material. The heated solvent flows via a pressure-holding valve and an inlet tube, a vacuum vessel, while the heated solvent is evaporated on or in a vacuum vessel.

In the company brochure PKG my "Modern vapor drying processes and plants", February 1992, Micafil Vakuumtechnik AG, Zurich MTV / E 0293000/22 Solvent vapor drying plants operating according to the vapor phase method are described with separate, outside or inside an autoclave solvent evaporators. All the devices used to carry out the described method, require an autoclave heater and in addition an evaporator with a complex temperature control for controlling the solvent vapor with high accuracy.

WO 98/35195 describes a device for drying a freshly painted H motor vehicle. This device includes a motor vehicle receiving box-shaped container, on the ceiling of a plenum for receiving hot air, at the bottom of a suction chamber and at its four corners vertically extending blowing devices are mounted. From the plenum, on the one hand through the ceiling of the container through a hot air flow is guided into the container, which is directed inside the container down. On the other hand, air is led from the plenum via blowers and pipes to the blowing devices and blown into the interior of the container. Here, the blowing devices are each arranged so that the exiting hot air impinges mainly horizontally on one of the four corners of the motor vehicle. Through cooperation of the downwards, slow and out of the blowing devices, rapid flow of hot gas turbulence are generated in the interior of the container, which accelerate the drying process.

Presentation of the invention

The present invention is based on the object to provide a device for drying a good by the vapor phase method, which allows a short heating time of the goods and, accordingly, a short cycle time of the material to be dried and which is also characterized by low energy consumption.

In the device according to the invention, the vacuum container accommodates at least two solvent steam generators which are arranged predominantly vertically along the drying material and respectively serve to generate a predominantly horizontally guided solvent vapor flow, the two solvent steam generators each have a flow channel designed for injection in the manner of a Venturi nozzle the heated solvent and entrained in the vacuum vessel circulating solvent vapor, and the two solvent evaporators are connected in series with each other so that they feed a predominantly horizontally circulating around the drying material solvent flow during operation of the device.

In the device according to the invention, therefore, the effect of the two solvent steam generators is added by series connection. This results in a high average velocity and a high solvent vapor throughput of the flow by feeding the predominantly horizontally circulating solvent vapor flow in the same direction. Because of the vertical extension of the solvent steam generator, a tangential solvent vapor flow is formed virtually over the entire circumference of the drying material. The thus excited flow allows optimal circulation and turbulence of the solvent vapor. As a result, a fast and homogeneous heating of the material to be dried on a whole Trocknungsgut largely the same temperature ensured. Likewise, the amount of energy required for heating the drying material and the heating time are greatly reduced.

Despite the short turnaround time and the low energy consumption, the device does not require any elaborate additional components in addition to the components required in conventional methods. The reduction of the heating time is mainly due to the fact that strong, throughout the heating phase practically constant injection of heated solvent a large circulation of solvent vapor and thus a high solvent vapor velocity is maintained even towards the end of the heating phase in the vacuum vessel. In order to achieve a good efficiency, the two solvent steam generators generally extend over the entire height of the drying material, respectively. of the vacuum container, but may also be only over a portion of the height of the Trocknungsguts, resp. the height of the vacuum container. Thus, in the device according to the invention having a lower solvent vapor temperature, the same heating rate of the material to be dried is achieved as in a drying device according to the prior art. A lower solvent vapor temperature, especially in the first phase of the heating, has a very positive effect on the depolymerization of a dry matter containing solids insulation. The service life of the material to be dried is considerably extended with high efficiency of the drying process.

Since the two solvent steam generators are each designed in the manner of a venturi nozzle and have a flow channel for injecting the heated solvent and for entraining a circulating in the vacuum vessel solvent vapor flow, a significantly increased solvent vapor velocity is achieved with a small amount of injected, heated solvent. At the same time, the solvent vapor flow exiting from the flow channel of the Venturi nozzle in and outside the flow channel of the Venturi nozzle entrains an increased amount of solvent vapor, which already circulates in the vacuum container. It will reach such a strong turbulence and thus increases the heat transfer to the material to be dried. A with minimal effort horizontally particularly effectively circulating around the drying material Solventdampfströmung is achieved when the at least two Solventdampferzeuger are separated by the Trocknungsgut.

If, in addition to the at least two vertically extended solvent steam generators, the vacuum container has at least one third solvent steam generator arranged above the material to be dried to produce a solvent vapor flow guided vertically downwards to the drying material, an additional increase in the turbulence of the mixed steam in the vacuum container is achieved. It then mixes the solvent vapor flow circulating horizontally around the drying material with the solvent vapor flow directed vertically downwards, thus forming a solvent vapor flow tangentially particularly intense around the entire material to be dried, which additionally optimizes the heating times and minimizes the temperature differences on the material to be dried. Optionally, the efficiency of the device according to the invention can be further increased by extending the third solvent steam generator predominantly horizontally along the material to be dried, and / or periodically feeding the solvent vapor flow directed vertically from above vertically downwards during the entire heating time. In order to achieve a solvent vapor flow flowing tangentially around the entire drying material, it is generally sufficient for the third solvent steam generator to extend over only a relatively small portion of the length or width of the material to be dried, and accordingly for the downwardly directed solvent vapor flow to be only one compared to the dimensions of the material to be dried having small width.

Advantageously, by means of the at least one second opening, a suction line which is attached to or in the material to be dried is guided for the return of mixed steam to the condensation device. Namely, a particularly high efficiency of the device according to the invention is achieved, since then a part of the mixing steam present in the interior of the vacuum container, which is led to the condensation device located outside the vacuum container, from the inner regions of the material to be dried or between two different copies of the material to be dried , For example, two winding blocks deducted becomes. This creates a negative pressure in the inner regions of the material to be dried and, advantageously, a solvent vapor flow from the outside to the inside. Even internal parts of the material to be dried are now heated rapidly, so that only small differences in temperature between inner and outer parts of the material to be dried can form in procedurally advantageous manner, and accordingly the drying time is substantially reduced.

The device according to the invention is particularly efficient if the material to be dried and at least one vertically extended solvent steam generator are arranged in an insert vessel enclosed by the vacuum container, since the flow circulating horizontally around the material to be dried then only has to develop in a small volume compared to the vacuum container. Since the flow cross section of the solvent vapor flow between the material to be dried and the wall of the reaction vessel is smaller than the corresponding flow cross section in the vacuum vessel, but without the reaction vessel, a large average velocity of the horizontally circulating solvent vapor flow can generally be achieved with only one vertically extended solvent generator and, in a corresponding manner, the material to be dried uniformly and be heated up quickly. Such an embodiment of the invention is particularly suitable if, after drying, the dried material is to be impregnated with a liquid, for example insulating oil or casting resin.

Description of the drawing

Fig.1

eine erste Ausführungsform der Trocknungsvorrichtung nach der Erfindung, enthaltend einen geschnitten dargestellten und Feststoffisolationen eines Transformators als Trocknungsgut aufnehmenden Vakuumbehälter, vier vertikal erstreckte und am Umfang des Vakuumbehälters platzierte Solventdampferzeuger, eine Vorrichtung zum Kondensieren von Mischdampf sowie zwei Absaugrohre für die Rückführung von Mischdampf zum Kondensator,

Fig.2

eine Ansicht von oben auf die Trocknungsvorrichtung nach Fig.1,

Fig.3

eine zweite Ausführungsform der Trocknungsvorrichtung nach der Erfindung, enthaltend neben den vier vertikal erstreckten Solventdampferzeugern zusätzlich noch zwei oben liegende, horizontal erstreckte Solventdampferzeuger,

Fig.4

eine Ansicht von oben auf die Trocknungsvorrichtung nach Fig.3,

Fig.5

eine dritte Ausführungsform der Trocknungsvorrichtung nach der Erfindung, bei der innerhalb des Vakuumbehälters das Trocknungsgut in einem Einsatzgefäss platziert ist und innerhalb des Einsatzgefäss vier vertikal erstreckte Solventdampferzeuger angeordnet sind, und

Fig.6

eine Ansicht von oben auf die Trocknungsvorrichtung nach Fig.5.

Preferred embodiments of the invention will be described with reference to the accompanying drawings. Hereby shows:

Fig.1

a first embodiment of the drying device according to the invention comprising a vacuum vessel shown cut and solid insulation of a transformer as drying material, four vertically extended and placed on the periphery of the vacuum tank solvent steam generator, a device for condensing mixed steam and two suction pipes for the return of mixed steam to the condenser,

Fig.2

a top view of the drying device after Fig.1 .

Figure 3

a second embodiment of the drying device according to the invention, comprising in addition to the four vertically extended solvent steam generators additionally two overhead, horizontally extended solvent steam generators,

Figure 4

a top view of the drying device after Figure 3 .

Figure 5

a third embodiment of the drying device according to the invention, in which within the vacuum container, the drying material is placed in a feed vessel and within the feed vessel, four vertically extended solvent steam generators are arranged, and

Figure 6

a top view of the drying device after Figure 5 ,

Ways to carry out the invention

In all figures, like reference numerals designate like-acting parts. The drying devices shown in the figures serve to dry good, in particular, the solid insulation of one or more electrical appliances as well as the removal of any insulating oil present in the insulation. The drying device after Fig.1 contains a vacuum-tight running container 1, which is loaded with a solid insulation electrical device, such as a transformer, or - as shown - even with the solid insulation containing active part 1.1 .. The heating energy is transferred in a Solventerhitzer 3 on the solvent. The solvent is generally a light oil having a significantly higher boiling point than water and a substantially lower boiling point than an insulating oil optionally present in the solid insulation. The solvent necessary for the heating of the dry material is fed from a non-listed solvent storage tank via the Solventabsperrventil 12.2 with the feed pump 2 to the Solventerhitzer 3. The heated solvent is fed via a Solventzuführleitung 3.2 and the valves 11 to 4 Solventdampferzeuger 4. The four solvent steam generators 4 each extend vertically, largely over the height of the vacuum container 1 and are approximately uniformly distributed on the circumference of the vacuum container 1. Each of the four solvent steam generators 4 contains a vertically extended solvent distribution pipe 4.0 with 5 vertically spaced injection openings or injection nozzles 4.1

The solvent distribution pipes 4.0 can be advantageously designed as exposed pipes with injection openings 4.1 and or injection nozzles. As a result, a cost-effective device is achieved. In the area of the injection openings 4.1, the narrowest cross-section in each of the four solvent steam generators 4 is the flow duct 4.3 designed in the manner of a Venturi nozzle, which is formed by a suitably curved Venturi guide plate 4.2 and the wall of the vacuum tank 1 such that it leaves the flow channel 4.3 and optionally solvent solvent flow contained 4.4 is rectified with the emerging from other solvent steam generators 4 Solventdampfströmungen 4.4. The vacuum tank 1 has at the bottom in its bottom a drain opening 1.2 for condensed solvent, as well as optionally washed out of the solvent from the solid insulation insulating oil. The drain opening 1.2 is connected via a solvent connection line 3.1 with a feed pump 2. The outlet of the feed pump 2 is connected to the Solventerhitzer 3 or alternatively via shut-off valve 12.3 with a solvent storage tank, not shown, or alternatively via 13.1 with an oil tank, not shown, for receiving the optionally present insulating oil, which was removed during drying of the material to be dried 1.1 by the solvent from the solid and subsequently separated by distillation from the solvent. In the inner parts of the material to be dried 1.1 or between the coils of the material to be dried 1.1.1 two suction tubes 7 are each mounted with a suction opening 7.1, which leads to the vacuum connection 1.3 of the mixed steam line 8 and to a mixed steam condenser. The mixed steam condenser 9 is connected to a vacuum pump 10. The mixed steam condenser 9 has 2 unregistered valves for emptying of solvent and water.

The construction of two additional embodiments of the in the drying device according to Fig.1 and 2 provided Solventdampferzeugers is from the FIGS. 3 and 4 as well as the FIGS. 5 and 6 seen.
In the embodiment according to 3 and 4 , Part of the solvent heated in the Solventerhitzer 3 Solventes via Solventzuführleitung 3.2 on the one hand at the same time the valves 11.1 and to the existing within the vacuum tank 1, two horizontal, overhead Solventdampferzeuger 5 out. The solvent steam generators 5 each extend horizontally, in part, over the entire length of the vacuum container 1. The solvent steam generator 5 contains a horizontal solvent distribution pipe 5.0, two vertically spaced injection openings or injection nozzles 5.1. The horizontal Solventverteilrohre 5.0 can be formed with advantage as exposed pipes with injection openings and or injectors 5.1. As a result, a cost-effective device is achieved. In the region of the injection openings 5.1, the narrowest cross-section is in the manner of a Venturi nozzle horizontal flow channels 5.3, which are formed by 2 suitable, curved Venturileitbleche 5.2, so that the emerging from the horizontal flow channels 5.3 Solventdampfströmungen 4.4 are directed vertically downwards.

In the embodiment according to Fig.5 and 6 is the material to be dried 1.1 placed within a feed vessel 6, which in turn within the vacuum container 1 lies. The two solvent steam generators 4 consisting of the components 4.0; 4.1; 4.2; 4.3 also arranged vertically within the insert vessel 6. The necessary for the heating of the material to be dried 1.1 Solvent is fed from a solvent storage tank, not shown in the figures via the Solventabsperrventil 12.2 with the feed pump 2 to the Solventerhitzer-3. The heated solvent is fed via a Solventzuführleitung 3.2, the valve 11, a solvent supply connection line 6.3 and a solvent connection line 6.4 to the lying within the insert vessel 6, vertical Solventdampferzeugern 4.

The solvent distribution pipes 4.0 can be advantageously designed as exposed pipes with injection openings and or injectors 4.1. As a result, a cost-effective device is achieved. In the region of the injection opening 4.1, the narrowest cross-section lies in the flow channel 4.3 designed in the manner of a Venturi nozzle, which is formed by a suitable curved Venturi guide plate 4.2 and the wall of the insert vessel 6 such that the solvent vapor flow emerging from the flow channel 4.3 and optionally also solvent are contained Solvent vapor flow 4.4 is rectified with the emerging from other solvent steam generators 4 Solventdampfströmungen 4.4. The insert vessel 6 has at the bottom in its bottom a drain opening 6.1 for condensed solvent, as well as for optionally washed out of the solvent from the solid insulation insulating oil or introduced into the insert vessel 6 Isolieroel. The drain opening 6.1 is connected via condensate connection line 6.2 and Solventabsperrventil 12.1 with a feed pump 2. The bottom of the vacuum container 1 is also via the condensate drain 1.2 and Solventabsperrventil 12 of the solvent connection line 3.1 connected to the feed pump 2. The bottom of the insert vessel 6 is connected via condensate drain 6.1 and condensate drain connecting line 6.2 with a oil shut-off valve 13. Oelbefüllung or oil evacuation of the insert vessel 6 are made possible.

The operation of the device is as follows: With the vacuum pump 10, the vacuum container 1 and the mixed steam condenser 9 are evacuated. At the same time from the solvent storage tank, not shown, a sufficient amount of solvent through the shut-off valve 12.2, the Feed pump 2 and the Solventerhitzer 3 fed into the vacuum tank 1. In the heating phase that follows, the solvent present in the vacuum tank 1 is circulated by the feed pump 2 and heated in the solvent heater 3 to a temperature slightly above a predetermined drying temperature. The heated solvent is at a higher pressure when heated. Upon discharge of the solvent from the injection openings 4.1 of the Solventverteilkanäle 4, the pressure in the solvent drops sharply while a part of the heated solvent evaporated while cooling by the amount of its heat of vaporization. The resulting solvent vapor 4.4 condenses on the active part and heats it with simultaneous evaporation of the water contained in the solid insulation, resulting in the formation of a solvent and steam containing mixed steam in the vacuum vessel 1. Solvent condensate obtained in the vacuum container 1 and optionally containing insulating oil flows to the condensate drain opening 1.2 and the solvent connecting pipe 3.1 and is returned to the solvent steam generators 4 with the feed pump 2 via the solvent heater 3 for evaporation. The solvent is advantageously injected at the narrowest point via the solvent injection openings 4.1 into the flow channels 4.3. This results in a particularly high flow velocity and a correspondingly high negative pressure. This leads to a jet effect, through which the mixed vapor 4.5 present in the vacuum container 1 is sucked into the flow channels 4.3. The aspirated mixed steam 4.5 mixes with the injected solvent and the solvent vapor 4.4 formed during injection. This produces the advantageous effect, on the one hand, of achieving fast and accurate temperature control of the solvent vapor 4.4 entering the vacuum vessel 1, and, on the other hand, circulating the mixed vapor at elevated speed turbulently in the vacuum vessel 1 by sucking in the mixed vapor into the flow channels 4.3.

Due to the vertical arrangement of at least two Solventdampferzeugern 4 in such a way that the exiting solvent vapor always has the same direction, creates a tangential solvent vapor flow high speed within the vacuum vessel, which flows around the drying object with turbulent turbulent, almost uniform Solventdampfströmung, creating a uniform heating of electrical drying material 1.1 is significantly accelerated.

If the insulation of the electrical material to be dried 1.1 contain insulating oil, this is washed out by the condensing solvent and mixes with the solvent to a solvent / oil mixture. The oil content is not evaporated in the solvent steam generator. Therefore, with continuous removal of mixed steam from the vacuum tank 1 and condensation of the extracted mixed steam in the mixed steam condenser 9, the oil content in the vacuum tank 1 steadily increases until practically only pure oil is present. This oil is emptied with the feed pump 2 via shut-off valve 13.1. Thereafter, via Solventeinlaßventil 12.2 of the feed pump 2, the solvent heater 3 solvent drawn back into the vacuum tank 1 and evaporated in the aforementioned manner.

Once the material to be dried 1.1 is heated to a temperature sufficient to dry the solid insulation respectively. to wash out any existing insulating oil, the feed pump 2 is switched off and the mixing steam present in the vacuum container 1 4.5 fed to the mixed steam condenser 9. By means of condensation of solvent and water vapor in the mixed steam condenser 9, the pressure in the vacuum tank 1 is lowered.
The pressure in the vacuum container 1 is lowered to such a low level until the material to be dried has reached the desired degree of drying.

In the embodiment of the drying device according to 3 and 4 is in addition to the under Fig.1 and 2 described procedure simultaneously or intermittently a portion of the heated solvent in the solvent heater 3 via the shut-off valves 11.1 the horizontal Solventdampferzeugern 5, containing the Solventverteilrohr 5.0, the Solventeinspritzöffnungen 5.1, the Venturileitbleche 5.2 and the flow channel 5.3, respectively. As a result of the horizontal position of the solvent steam generator and the large injection speed of the solvent, the resulting solvent vapor flows vertically downwards at high speed and forms with the horizontal solvent vapor flow of the drying apparatus downstream of the Fig. 1 and 2 a rotating Solventdampfströmung 4.7 high turbulence, which flows around the material to be dried 1.1 tangentially, which ensures a rapid and uniform heating of the material to be dried 1.1 in an optimal manner.

In the embodiment of the drying device according to the FIGS. 5 and 6 will - as with the Figures 1 and 2 described - the solvent heated in the solvent heater 3 the vertical Solventdampferzeugern 4, which are the components 4.0; 4.1; 4.2; 4.3 included, fed and evaporated a part of the solvent. The solvent vapor now condenses on the one hand on the placed in the insert vessel 6 drying 1.1 and on the other hand at the same time on the walls of the vacuum vessel 1. The resulting in the reaction vessel 6 and optionally containing insulating solvent condensate flows through the Kondensatablauföffnung 6.1, the condensate drain connecting line 6.2 and the Solventabsperrventil 12.1 the Solventverbindungsleitung 3.1 and is supplied to the feed pump 2 via the solvent heater 3 for evaporation back to the vertical Solventdampferzeugern 4. The resulting in the vacuum tank 1 solvent condensate flows through the condensate drain 1.2 and the Solventabsperrventil 12 of the solvent connection line 3.1 and is also supplied to the feed pump 2, via the solvent heater 3 for evaporation back to the solvent steam generators 4.

By arranging the Solventdampferzeuger 4 within the feed vessel 6 to form the emerging from the solvent steam generators 4, rectified horizontal Solventdampfströmungen 4.4 arises within the feed tank 6, a tangential mixed steam flow 4.5 high speed resp. Turbulence. This ensures when placing the material to be dried 1.1 in the use vessel 6, which is located within a vacuum container 1, a particularly rapid and uniform heating of the material to be dried 1.1 respectively an optimally short drying time. After drying, the insert vessel 6 can be filled via oil shut-off valve 13 with oil until the drying material 1.1 is flooded with oil.

LIST OF REFERENCE NUMBERS

1

vacuum vessel

1.1

Drying material (electrical device, active part of the device)

1.1.1

Coil of drying material

1.2

condensate drain

1.3

vacuum connection

2

feed pump

3

Solventerhitzer

3.1

Solvent connecting line

3.2

Solventzuführleitung

4

Solvent steam generator (vertical)

4.0

Solvent distribution pipe (vertical)

4.1

Solvent injection port

4.2

Venturi baffle (vertical)

4.3

Flow channel (vertical)

4.4

Solvent / solvent vapor flow

4.5

Mixed vapor flow

4.6

Mixed steam flow to the suction opening

4.7

rotating solvent vapor flow

5

Solvent steam generator (horizontal)

5.0

Solvent distribution pipe (horizontal)

5.1

Solvent injection port

5.2

Venturi guide plate (horizontal)

5.3

Flow channel (horizontal)

6

use vessel

6.1, 6.2

condensate drain

6.3.

Solvent supply interconnecting line

6.4

Solvent connecting line

7

suction tube

7.1

suction

8th

Mixing steam line

9

Mixing steam condenser

10

vacuum pump

11

Solvent shut-off valve to solvent distribution pipe (vertical)

11.1

Solvent shut-off valve to solvent distribution pipe (horizontal)

12

Solventabsperrventil to vacuum tank

12.1

Solventabsperrventil to insert vessel

12.2

Solvent inlet valve

12.3

Solvent drain valve

13

Oelabsperrventil

13.1

Oelentleerungsventil

Claims (6)

1. A device for drying a product (1.1), preferably solid insulations of an electrical device, by the vapour-phase method with a vacuum tank (1) for accommodating the product to be dried (1.1) containing at least water, if necessary also insulating oil and contaminants, and with at least one solvent vapour generator (4) disposed in the interior of the vacuum tank (1), wherein the vacuum tank comprises at least one first opening for admitting heated solvent to the at least one solvent vapour generator (4) and at least one second opening for admitting a mixed vapour (4.5) containing at least water vapour and solvent vapour to a condensation device, characterised in that the vacuum tank (1) accommodates at least two solvent vapour generators (4), which are disposed spatially separated from one another and which extend largely vertically in each case along the product to be dried (1.1) and in each case serve to generate a solvent vapour flow (4.4) conveyed largely horizontally, that the two solvent vapour generators (4) each comprise a flow channel (4.3) constituted in the manner of a Venturi nozzle for injecting the heated solvent and for entraining solvent vapour circulating in the vacuum tank (1), and that the two solvent evaporators are connected to one another in series such that, when the device is in operation, they feed a solvent vapour flow circulating largely horizontally about the product to be dried (1.1).
2. The device according to claim 1, characterised in that the at least two solvent vapour generators (4) are separated from one another by the product to be dried (1.1).
3. The device according to any one of claims 1 or 2, characterised in that the vacuum tank (1) accommodates at least a third solvent vapour generator (5) disposed above the product to be dried (1.1) for the purpose of generating a solvent vapour flow (4.4) conveyed downwards to the product to be dried (1.1).
4. The device according to claim 3, characterised in that the at least one third solvent vapour generator (5) extends largely horizontally along the product to be dried (1.1).
5. The device according to any one of claims 1 to 4, characterised in that a suction line positioned on or in the product to be dried (1.1) for the purpose of feeding back the mixed vapour (4.5) to the condensation device is passed though the at least one second opening.
6. The device according to any one of claims 1 to 5, characterised in that the product to be dried (1.1) and the at least two solvent vapour generators (4) are disposed in an insert vessel (6) surrounded by the vacuum tank (1) and accommodating the product to be dried (1.1).

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