EP0618403B1 - Container for an electrode boiler - Google Patents

Description

The invention relates to an evaporation vessel for an electrode evaporator according to the preamble of independent patent claim 1.

Electrode evaporators are called steam generators, in which a single or multi-phase alternating current is passed through the water via two or more electrodes and the water itself is used as a heating resistor for generating the heat required for the evaporation. They are mainly used in air humidifiers for ventilation and air conditioning systems or for direct room humidification.
From GB-A-663 286 electrode evaporators are known, the evaporation vessel of which comprises two or more electrodes, between which shielding plates are arranged. The electrodes and the shielding plates can be electrically connected through bushings in the wall of the evaporation vessel and are held by the wall.

Depending on the required performance and depending on the conditions of the electrical network, which differ greatly depending on the location and geographical region (different nominal voltages, number of phases, etc.), the devices and especially the evaporation vessels must be designed very differently (especially with regard to number, shape and arrangement of the electrodes). In the known electrode evaporators, this means on the one hand for the manufacturer to produce a large number of different device types, and on the other hand for the intermediate and end trade to keep a large number of different devices and spare parts available.

It is therefore an object of the present invention to propose a structural design of the evaporation vessel which allows a large spectrum of different device types to be provided with a small number of different components in a variable structure.

This object is achieved with the features defined in the characterizing part of independent claim 1. Preferred embodiments are the subject of the dependent claims.

The essence of the invention is that in an evaporation vessel of the type mentioned at the beginning, at least one of the electrodes is held by means of at least one plug-in part inserted into one of the bushings. This allows electrodes to be arranged in different positions and in different positions, so that different arrangements can be implemented with the same type of electrode. The plug-in part is provided with a locking device which, on the one hand, automatically locks the plug-in part inserted into a bushing and, on the other hand, can be released again without tools if the plug-in part or the electrode is to be removed again.

This design also allows the electrodes to be quickly assembled and disassembled, and represents a significant simplification compared to the conventional design, in which the electrodes are firmly inserted in the evaporation vessel, in many cases injected directly into the vessel wall or then firmly screwed.

The simplicity of the installation and removal of the electrodes achieved in this way, in addition to the advantages that result from cleaning and maintenance, is extremely advantageous, particularly from an ecological point of view, because electrodes that have become unusable after a certain period of time due to mineral deposits can now be used independently replace the evaporation vessel and, if necessary, even clean and reuse it. Compared to conventional devices, this means less waste and a significant reduction in environmental pollution, because up to now after the end of the service life, i.e. as soon as the mineral deposits are too large, the entire evaporation vessel together with the electrodes has to be replaced, since the electrodes have to be removed is not possible at all, or would then be far too complex.

When assembling an evaporation vessel for a specific device type, suitable electrodes are mounted in a suitable position and position by means of plug-in parts inserted in appropriately selected bushings. In principle, a certain variability is achieved if only one of the electrodes can be mounted in this way; in a preferred embodiment, however, all electrodes are held in one or more of the bushings by means of the plug-in parts mentioned. Unused bushings can be closed with additional plug-in parts.

Different rotational positions can be provided for the same electrode, for example a) bent against the vessel wall and b) away from it. To determine one or more rotational positions of the electrode or the axial orientation of the Plug-in parts in the bushing are expediently configured on the plug-in part and on the evaporation vessel interacting positioning means. Such positioning means can consist, for example, in a special shape of the cross-sectional contour of the feedthrough and plug-in part or can also be realized with positioning cams and corresponding recesses for receiving the positioning cams in the other part.

In addition to the electrodes, other functional parts, for example sensors for the water level and the like, often have to be arranged in the interior of the evaporation vessel. These further functional parts are also advantageously held in one of the bushings by means of a plug-in part.

The course of the electrical field can be influenced by inserting a blind electrode, that is to say an electrically conductive, but not electrically connected or possibly connected to a neutral conductor, into the electrode arrangement, as the person skilled in the art will immediately recognize. By a suitable choice of the size and shape of the dummy electrode, the mode of operation of the electric field can be adapted to different requirements, so that the other (active) electrodes have to be adjusted less or not at all. This means that only a few types of electrodes are required to cover a wide range of devices.

For reasons of symmetry, it will generally be expedient to arrange the dummy electrode in the center of the electrode arrangement, more precisely, coaxially to the central axis of symmetry of the arrangement formed by the other electrodes. As a simple, advantageous figure for the A hollow cylinder is proposed for the dummy electrode; in principle, however, any shapes, depending on the intended use, are also conceivable.

Another problem, also known to the person skilled in the art under the term “leakage current”, can be solved in a simple manner with a dummy electrode. If the dummy electrode is arranged in such a way that it electrically shields the area near the water inlet or outlet, for example with its lower section, this prevents the formation of electrical potential differences in this area that would otherwise occur when (electrical conductive) water can generate an undesirable and dangerous electrical current in the draining water.

• Fig. 1 in perspektivischer, teilweise aufgeschnittener Darstellung ein erfindungsgemässes Verdampfungsgefäss,
• Fig. 2 eine Aufsicht auf das Verdampfungsgefäss von Figur 1,
• Fig. 3 in Perspektivdarstellung den Deckel des Verdampfungsgefässes mit zwei darin montierten aktiven Elektroden und einer Blindelektrode, zusammen mit einem Sieb mit Halteelementen zur Abstützung der Elektroden in ihrem unteren Bereich,
• Fig. 4 einen Vertikalschnitt eines in eine Durchführung im Deckel des Verdampfungsgefässes eingesteckten Steckteils, zusammen mit einem Stecker für den elektrischen Anschluss der Elektrode,
• Fig. 5 eine Seitenansicht des Steckteils von Figur 4,
• Fig. 6 eine Aufsicht auf das Steckteil von Figur 5,
• Fig. 7 einen gegenüber Figur 4 um 90° gedrehten Vertikalschnitt einer Durchführung,
• Fig. 8 eine gegenüber Figur 5 um 90° gedrehte, teilweise geschnittene Seitenansicht des Steckteils,
• Fig. 9, Fig. 10, Fig. 11, Fig. 12 verschiedene mögliche Elektrodenanordnungen in schematischer, von oben betrachteter Darstellung,
• Fig. 13 eine bevorzugte Ausführungsform der Verbindung von Deckel und Unterteil des Verdampfungsgefässes, anhand einer Seitenansicht von Unterteil und von diesem getrenntem Deckel,
• Fig. 14 eine Aufsicht auf das Unterteil des Verdampfungsgefässes und
• Fig. 15 eine ausschnittweise Seitenansicht des geschlossenen Verdampfungsgefässes, betrachtet aus Richtung A in Figur 13.

In the following, an embodiment is described for a more detailed explanation of the invention with reference to the accompanying drawings. Show:

• 1 is a perspective, partially cut-open representation of an evaporation vessel according to the invention,
• 2 is a plan view of the evaporation vessel of Figure 1,
• 3 is a perspective view of the lid of the evaporation vessel with two active electrodes and a blind electrode mounted therein, together with a sieve with holding elements for supporting the electrodes in their lower area,
• 4 shows a vertical section of a plug-in part inserted into a bushing in the lid of the evaporation vessel, together with a plug for the electrical connection of the electrode,
• 5 is a side view of the plug part of Figure 4,
• 6 is a plan view of the plug part of FIG. 5,
• 7 shows a vertical section of a bushing rotated through 90 ° with respect to FIG. 4,
• 8 is a partially sectioned side view of the plug-in part rotated by 90 ° with respect to FIG. 5,
• 9, 10, 11, 12 different possible electrode arrangements in a schematic representation viewed from above,
• 13 shows a preferred embodiment of the connection of the lid and the lower part of the evaporation vessel, on the basis of a side view of the lower part and the lid separated therefrom,
• Fig. 14 is a plan view of the lower part of the evaporation vessel and
• 15 is a partial side view of the closed evaporation vessel, viewed from direction A in FIG. 13.

From the figures 1, 2 and 13, the evaporation vessel designated in its entirety with 2 can be seen. It is usually located in a housing 4 (indicated by dashed lines in FIG. 1) of an air humidification device. The details of such a device, such as water connection, steam distributor, electronic control, etc., which are insignificant and known to the person skilled in the art, are not shown. The evaporation vessel 2 consists of a lower part 6, in the bottom of which a water inlet or outlet 8 is arranged, and a lid 10 with a steam outlet 12. Also shown are support feet 14 formed on the lower part, on which the lower part is used during assembly or maintenance work can be set up free-standing.

A number of bushings, a total of seven, are formed in the cover 10, four of which are designated 16.1 closer to the edge and three designated 16.2 closer to the center of the cover. Plug-in parts 18 can be inserted into these bushings 16.1 or 16.2, by means of which electrodes can be held in the cover 10, as will be described in more detail below.

In the illustration of FIGS. 1 and 2, for the sake of clarity, only a single plug-in part 18 is inserted into one of the bushings 16.1, which one Rod 20, which is part of an electrode, carries. FIG. 3 shows an arrangement of three electrodes, consisting of two electrodes 22 of the same type, which are "real" in the usual sense, that is to say electrodes which are connected to a supply voltage during operation, and an electrode 24 which is designed as a dummy electrode. Another electrode 22, which would be arranged towards the viewer, is omitted in the figure (cf. FIG. 11). As already generally described above, the dummy electrode 24 is not connected to a supply voltage, but is kept electrically insulated in the wall of the evaporation vessel 2, or is optionally connected to a neutral conductor. It serves to a certain extent passively to influence the electric field generated by the active electrodes 22.

In the exemplary embodiment shown here, each electrode 22 consists of a rod 20 and an electrode body 22.1 fastened thereon, and the electrode 24 consists of two rods 20 and an electrode body 24.1 fastened to these rods. Both the rods 20 and the electrode bodies 22.1 and 24.1 are made of an electrically conductive material, preferably metal. All electrodes are held in the cover 10 by means of plug-in parts, which are each fastened to one of the rods 20, specifically the electrodes 22 in bushings 16.1 and the dummy electrode 24 in bushings 16.2.

For additional stabilization of the electrodes, as can be seen in FIGS. 1 and 3, holding elements 26 can be provided which are attached, for example integrally formed, to a sieve 28 which is usually present anyway and is arranged at the bottom in the evaporation vessel. In the exemplary embodiment, the holding elements 26 are sleeves formed, in which the lower ends of the rods 20 are inserted.

The details of implementation 16.1 or 16.2 and plug-in part 18 can best be seen in FIGS. 5 to 8. The bushings 16.1, 16.2 are of essentially the same design, so that the same plug-in part can be used in both. They have a circular cross section and are surrounded by annular guide flanges 30 and 32, which support the plug-in part 18 laterally. The contour of the plug-in part 18 is adapted to the bushing 16.1 or 16.2 and the guide flanges 30, 32 in a closely fitting manner. 34 with a sealing ring is designated. If an electrode is to be held by means of a plug-in part 18, it is firmly attached to the plug-in part. In the embodiment shown, the rod 20 extends for this purpose through a central bore in the plug-in part 18; the upper end of the rod can thus simultaneously serve as an electrical connecting pin for a connecting plug 36.

As a latching device which is able to hold the plug-in part 18 automatically latching in one of the bushings 16.1, 16.2, the latter has two elastically flexible tongues 38 which are provided with a latching cam 40 at their free end. The locking cam 40 is tapered in the direction of insertion and has a locking projection 42 which, when the plug-in part is inserted, engages behind a locking edge 44, here the edge of the guide flange 30. If a plug-in part 18 is inserted into one of the bushings 16.1, 16.2, the tongues 38 run with their wedge surfaces on the edge of the bushing and are thereby bent inward so far, that the plug-in part can be retracted further into its end position. The length of the tongues 38 is selected so that the latching cam 40 is exposed again exactly in the end position, thus being pushed outwards by the elasticity of the tongues 38 and engaging behind the latching edge 44. To remove the plug-in part from the bushing, the two tongues 38 can be pressed against one another at their projecting ends, for example with two fingers, until the catch is released and the plug-in part can be pulled out. As can be seen in FIG. 4, the connector plug 36 can also advantageously be used to secure the tongues 38 in their latching position.

According to a preferred embodiment, positioning cams 46 are provided on the plug-in part 18 and corresponding slot-shaped recesses 48 are provided in the guide flange 32. The positioning cams 46 and recesses 48 form interacting positioning means which ensure that the plug-in part 18 can only be inserted into one of the bushings 16.1, 16.2 in certain axial orientations. In the embodiment shown in FIGS. 4 to 8, for example, the plug-in part 18 can only be plugged in in two positions, which differ by a rotation through 180 ° about the main axis of the plug-in part.

Four examples are given in FIGS. 9 to 12 to illustrate the various possibilities which the invention offers in order to implement different electrode arrangements in the same evaporation vessel with only a few electrode types. The position of the rods 20 each correspond to a position of the bushings 16.1 and 16.2, which can best be seen in FIG. 2. The arrangement in Figure 9 is for two-phase Alternating current is used and comprises two electrodes 22 and a dummy electrode 24, both of the type described above with reference to FIG. 3. The arrangement in FIG. 10 is suitable for three-phase alternating current; it consists of three electrodes 22 which, in contrast to FIG. 9, are oriented inwardly curved. FIG. 11 shows the arrangement of FIG. 10, supplemented by a dummy electrode 24. Two possible positions are indicated for the electrodes 22, one bent inwards and one outwards. The arrangement can be adapted to different steam outputs by suitable choice of the position of the electrodes. In addition, an arrangement with completely different electrodes is shown in FIG. These are three large-area electrodes 50, as are used for so-called fully demineralized water.

In a preferred embodiment of the evaporation vessel, shown in FIGS. 13 to 15, the connection between the lower part 6 and the lid 10 of the evaporation vessel 2 is implemented in the manner of a bayonet catch. This makes handling particularly easy when opening and closing the vessel, since only a short rotation is necessary, and in particular makes it easier for the user to replace the electrodes. The bayonet catch is formed by a number of first, outwardly projecting cams 52 on the lower part 6 and a corresponding number of second, inwardly projecting cams 54 on an annular web 56 of the cover which overlaps the edge of the lower part and the first cams 52. The cams 52 and 54 have run-on surfaces 58 and 60, which face one another when the cover is in place and are slightly inclined with respect to the closure plane, so that by rotating the cover relative to the Lower part the two parts are moved towards each other until the edge of the lower part 6 is pressed against a sealing ring 62 inserted in the cover 10 and the closure is firmly seated. Two laterally formed ribs 64 and 66 on the web 56 and on the lower part 6 form an additional stop for the closing rotation.

Claims (15)

1. Evaporating container for an electrode evaporator with an electrode arrangement comprising at least two electrodes which are held in the wall of the evaporating container (2) having a plurality of openings (16.1, 16.2), and which are electrically connectable from the outside of the evaporating container, characterised in that it comprises at least one plug-in unit (18) which can be inserted into the openings (16.1, 16.2) and which is provided with a locating device (38, 40, 42) which automatically holds in place the plug-in unit (18) when said unit is inserted into one of the openings (16.1, 16.2) and which can be released without requiring the use of tools for removal of the plug-in unit (18) from the opening (16.1, 16.2), and that at least one of the electrodes (22, 24, 50) is held in the container wall by means of such a plug-in unit (18) inserted in one of the openings (16.1, 16.2).
2. Evaporating container according to claim 1,
   characterised in that the arrangement of electrodes includes a blind electrode (24) which is not electrically connected or which is connected to a neutral conductor.
3. Evaporating container according to claim 2,
   characterised in that the blind electrode (24) is arranged substantially coaxially with the central axis of symmetry of the arrangement of the remaining electrodes (22).
4. Evaporating container according to claim 2 or 3, characterised in that the blind electrode (24) is shaped as a hollow cylinder.
5. Evaporating container according to one of claims 2 to 4, fitted with a water inlet/outlet (8), characterised in that the blind electrode (24) is arranged so as to neutralise the electrical field in the area of the water inlet / outlet (8).
6. Evaporating container according to one of claims 1 to 5, characterised in that all electrodes (22, 24, 50) are held in the container wall by at least one plug-in unit (18) which is inserted into one of the openings (16.1, 16.2).
7. Evaporating container according to one of claims 1 to 6, characterised in that a suitable number of openings (16.1, 16.2) are arranged in such a way as to allow the realisation of a variety of electrode configurations.
8. Evaporating container according to one of claims 1 to 7, characterised in that cooperating positioning means (46, 48) are provided on the plug-in unit (18) and the evaporating container (2) for setting the axial position of the plug-in unit (18) in one of the openings (16.1, 16.2).
9. Evaporating container according to one of claims 1 to 8, characterised in that additional function units, arranged in the interior of the container (2), for example sensors, are held in the container wall by means of at least one of the plug-in units (18) inserted in one of the openings (16.1, 16.2).
10. Evaporating container according to one of claims 1 to 9, characterised in that the openings (16.1, 16.2) are provided in the upper lid wall.
11. Evaporating container according to one of claims 1 to 10, characterised in that the lower ends of the electrodes (22, 24, 50) are supported in holding elements (26) which are provided on a screen (28) at the bottom of the evaporating container (2).
12. Evaporating container according to one of claims 1 to 11, characterised in that guide flanges (30, 32) are provided, extending inwards and/or outwards from the container wall, to support laterally the plug-in units (18).
13. Evaporating container according to one of claims 1 to 12, characterised in that the locating device on the plug-in unit (18) comprises at least two elastically-flexible tongues (38), which have a locating cam (40) on their free end which is wedge-shaped, decreasing in thickness in the direction in which it is inserted and has a locating projection (42) counter to the direction in which it is inserted which acts on an assigned locating edge (44) on the evaporating container (2) on insertion.
14. Evaporating container according to one of claims 1 to 13, characterised in that this has a lower part (6) and a lid (10) which are joinable together by means of a bayonet type of lock.
15. Evaporating container according to claim 14,
    characterised in that the lower part (6) has a circular opening, around the rim of which a plurality of outwardly directed primary lugs (52) are distributed, the lid (10) having a flange (56) which overlaps the opening and the primary lugs (52), around the rim of which a plurality of inwardly directed secondary lugs (54) are distributed and the primary (52) and secondary (54) lugs each having inclining surfaces (58, 60) which act in combination as a bayonet-lock.

Images