EP1859200B1 - Steam generator comprising a swirling device - Google Patents

Description

The present invention relates to a steam generator with a swirling device, as defined in the preamble of independent claim 1.

Steam generators are used, for example, for humidification and usually comprise an evaporation vessel, which is partially filled with water. The water is heated and vaporized with a heater, such as electrodes or electrical resistors, precipitating mineral salts, which are removed from the evaporation vessel from time to time by blowdown. For this purpose, the evaporation vessel to a water outlet, for example, in a in the US-A-4,221,955 disclosed steam generator is arranged in a side wall of the evaporation vessel.

A major problem when using very calcareous water is the calcification and rapid growth of the relatively small water outlet and the sedimentation of lime on the bottom of the evaporation vessel, which often make a complex cleaning necessary after a short time.

An Indian EP-A-0 715 121 Therefore, the disclosed steam generator has been provided with an air supply device which opens into the bottom or near the bottom of the evaporation vessel. By periodically blowing air through, the water can be swirled up to prevent encrustation.

In the in the US-A-4,221,955 Although disclosed steam generator reduces a arranged above the evaporation vessel bottom impeller as Verwirbelungseinrichtung the sedimentation of lime, but this is just as little prevented as the calcification of the water flow. The impeller is in fact not used for this purpose, but to increase the steam power without adding more water. This increase in steam efficiency is due to the fact that, as the impeller rotates, the water surface is vortex-shaped conically deformed, which increases the electrode immersion depth and thus the steam output. Turning off the impeller lowers the water level, reducing or even stopping steam production. The sedimentation of lime then starts again fully. During normal operation of the steam generator, the impeller is often switched on and off, so that the Kalksedimentation is reduced only temporarily. Moreover, the effect of the impeller hardly reaches as far as the water drain arranged in a side wall of the evaporation vessel, so that its calcification is not prevented.

In the EP-A-0 511 525 a steam generator is disclosed in which a slowly rotating propeller is arranged in a sediment collection chamber below a heating chamber having a heating device. The propeller serves as a sensor to measure the amount of deposited salt in the sediment collection chamber by being braked by high salt concentrations. Due to its slow rotation, it does not act as a swirling device.

In view of the problem of the rapid need for certain types of water costly cleaning of the steam generator due to the calcification of the water flow and sedimentation of lime in the previously known steam generators, the invention has the object to provide a steam generator of the type mentioned, in which less often a complex decalcification with associated steam generator downtime must be performed.
This object is achieved by the inventive steam generator, as defined in the independent claim 1 and in the independent claim 2. Preferred embodiments will become apparent from the dependent claims.
The essence of the invention consists in the following: A steam generator comprises an evaporation vessel which has a bottom and a water outlet. A heating device is arranged in the evaporation vessel and a swirling device is arranged below the heating device. According to the invention, the water outlet in the bottom of the evaporation vessel and the swirling device are arranged partly in and partly vertically above the water outlet or completely in the water outlet. The inventive arrangement of the water drain and the swirling device, which runs practically continuously during operation, a vortex is generated during operation in the water of the evaporation vessel and in particular in the water outlet. In this way, the lime is constantly moved, in particular in the area of the water outlet, and thus kept suspended in small particle size. At the same time, the part of the heating device immersed in the water is also flowed through by water at a relatively high velocity, which also counteracts limescale deposition.
By keeping the lime in suspension, the growth of large lime crystals are prevented and it sediments less lime on the evaporation vessel bottom. Rapid calcification of the water drain and the heater is prevented. The levitated lime can also be easily slurried, including the vortex contributes to the water flow, which causes a suction effect.

In a further type of embodiment of the invention, in the steam generator according to the invention, the swirling device is arranged completely in the water outlet. This results in an optimal soye effect for the slurrying and, moreover, a calcification of the water flow can be virtually ruled out.
Advantageously, the water outlet is arranged centrally in the bottom of the evaporation vessel. This allows for optimal Blasting and, together with a centric arrangement of the turbulizer, result in optimum formation of the water vortex created during operation, which thus ideally captures the entire water present in the evaporator vessel.

Preferably, the bottom of the evaporation vessel is funnel-shaped. On the one hand, this leads to a diversion of the vortex energy generated by the turbulence device, mainly in the direction of the heating device, thus ensuring its intensive flow around it. On the other hand, the funnel shape additionally prevents quiet zones with a tendency to calcification.

Preferably, a funnel-shaped part is arranged in the water outlet, in which the swirling device projects from below. With such a funnel-shaped contour, the vortex energy generated by the swirling device can be directed in a more targeted manner in the direction of the heating device.

Advantageously, the funnel-shaped part is formed like a sieve and divides the water drain into a evaporation vessel side part and a water outlet side part. The sieve-like funnel-shaped part thus creates a protected zone for the water outlet side part by catching falling large pieces of lime and does not let pass. In this way, for example, a Wasserauslass- or a water inlet opening in the water outlet side part can be secured against clogging by large pieces of lime.

In a preferred embodiment, the turbulizer is an impeller. Such an impeller generates an optimal vortex with a simple structure.

Advantageously, the impeller has vanes located substantially within the funnel-shaped portion, as well as vanes located substantially below the funnel-shaped portion in the water outlet-side portion of the water drain. With such a double-decker impeller on the one hand, a main vortex can be generated, which keeps the lime particles in the evaporation vessel small and in suspension and ensures good flow around the heater. On the other hand, at the same time the water in the water outlet-side part of the water outlet, can be kept in motion via the abgeschlämmt or fed to the water at the same time.

In an alternative advantageous embodiment, the swirling device is a worm wheel, a wobble plate or a swirler having a plurality of slats. Even with such simple turbulators, an efficient vortex can be generated.

Advantageously, the drive of the swirling device takes place via a radially acting magnetic coupling. The swirling device can thus be driven by a motor arranged outside the evaporation vessel without the vessel wall having to be penetrated by a mechanical part. Elaborate seals can be avoided. In addition, eliminates the risk that a blocked, for example by calcification swirling simultaneously blocked the engine, which could damage this.

The steam generator according to the invention preferably has a separation device for separating water and lime for the discharge water draining from the water outlet. Thus, the comparatively small lime particles can be trapped before they get into the continuing Abschlämmungsverrohrung, possibly lower there and lead to blockages.

The heating device advantageously comprises at least two electrodes or at least one resistance heating element.

Fig. 1

- ein erstes Ausführungsbeispiel eines erfindungsgemässen Dampferzeugers in teilweise geschnittener perspektivischer Ansicht;

Fig. 2

- eine Schnittansicht eines unteren Teils des Dampferzeugers von Fig. 1;

Fig. 3

- eine Explosionsansicht des Flügelrads, des Wasserablaufs und des Antriebs des Flügelrads des Dampferzeugers von Fig. 1;

Fig. 4

- die Dampferzeugerteile von Fig. 3 in zusammengebauter Form in teilweise geschnittener perspektivischer Ansicht;

Fig. 5

- einen unteren Teil des Dampferzeugers von Fig. 1 mit einer Separationseinrichtung in Form eines Absetzbeckens in teilweise geschnittener perspektivischer Ansicht;

Fig. 6

- einen unteren Teil des Dampferzeugers von Fig. 1 mit einer Separationseinrichtung in Form einer Filtereinrichtung in teilweise geschnittener perspektivischer Ansicht;

Fig. 7

- den unteren Teil des Dampferzeugers mit Filtereinrichtung von Fig. 6 in einer Schnittansicht;

Fig. 8

- eine Schnittansicht eines unteren Teils eines erfindungsgemässen Dampferzeugers gemäss einem zweiten Ausführungsbeispiel;

Fig. 9

- das Flügelrad des Dampferzeugers von Fig. 8;

Fig. 10

- eine Schnittansicht eines unteren Teils eines erfindungsgemässen Dampferzeugers ohne Magnetkupplung gemäss einem dritten Ausführungsbeispiel;

Fig. 11

- schematisch einen unteren Teil eines erfindungsgemässen Dampferzeugers gemäss einem vierten Ausführungsbeispiel;

Fig. 12

- eine Verwirbelungseinrichtung in Form eines Schneckenrads;

Fig. 13

- eine Verwirbelungseinrichtung in Form einer Wabbelscheibe; und

Fig. 14

- eine Verwirbelungseinrichtung in Form eines eine Mehrzahl von Lamellen aufweisenden Verwirblers.

In the following, the steam generator according to the invention will be described in more detail with reference to the accompanying drawings with reference to exemplary embodiments. Show it:

Fig. 1

- A first embodiment of an inventive steam generator in a partially sectioned perspective view;

Fig. 2

a sectional view of a lower part of the steam generator of Fig. 1 ;

Fig. 3

- An exploded view of the impeller, the water drain and the drive of the impeller of the steam generator of Fig. 1 ;

Fig. 4

- the steam generator parts of Fig. 3 in assembled form in a partially sectioned perspective view;

Fig. 5

- a lower part of the steam generator of Fig. 1 with a separation device in the form of a settling basin in a partially sectioned perspective view;

Fig. 6

- a lower part of the steam generator of Fig. 1 with a separation device in the form of a filter device in a partially sectioned perspective view;

Fig. 7

- the lower part of the steam generator with filter device of Fig. 6 in a sectional view;

Fig. 8

- A sectional view of a lower part of an inventive steam generator according to a second embodiment;

Fig. 9

- the impeller of the steam generator of Fig. 8 ;

Fig. 10

- A sectional view of a lower part of an inventive steam generator without magnetic coupling according to a third embodiment;

Fig. 11

schematically a lower part of a steam generator according to the invention according to a fourth embodiment;

Fig. 12

a swirling device in the form of a worm wheel;

Fig. 13

- A swirling device in the form of a wobble plate; and

Fig. 14

- A swirling device in the form of a plurality of slats having swirlers.

In the in the Fig. 1 to 4 A steam generator 1 according to the invention comprises an evaporation vessel 2 with a funnel-shaped bottom 21, a substantially cylindrical side wall 23 and a ceiling 24. Within the evaporation vessel 2, a heating device 3 is arranged which comprises a plurality of electrodes 31 fixed to the ceiling 24 Have power connectors 311 which project through the ceiling 24 through outward.

Centric in the bottom 21 of the evaporation vessel 2, a water outlet 22 is arranged. In the center of the bottom 21 an opening is formed for this purpose, which is laterally bounded by approximately vertically upwardly and downwardly projecting annular bottom portions 221 and 222, respectively. A drain housing has a substantially cylindrical wall 223 which attaches externally to the annular bottom portion 222 and extends downwardly therefrom. Between the substantially cylindrical wall 223, the downwardly projecting annular bottom part 222 and a ring member 25, an O-ring seal 26 is held. A drain casing bottom 224 limits the water drain 22 leading in operation to the bottom.

In the drain housing a funnel-shaped part 5 and a vortex impeller 4 are arranged, which protrudes from below into the funnel-shaped part 5. The funnel-shaped part 5 is formed like a sieve and divides the water outlet 22 into a evaporation vessel side part and a water outlet side part. It is supported by a support cylinder 51, which rests on the drain housing floor 224. On the one hand, the funnel-shaped part 5 allows the water to pass from the top to the bottom and from the bottom to the top, and on the other hand it ensures that no excessively large lime pieces enter the water outlet-side part. During operation, the funnel shape also directs the water flow and the vortex energy in the direction of the heating device 3.

For refilling fresh water into the evaporation vessel 2, a water inlet 6 passes through the cylindrical wall 223 of the drain housing and the support cylinder 51 of the funnel-shaped part 5. These are also provided for draining with water outlet openings 71 and 72, to which a water outlet 7 connects. The transition from the water outlet opening 71 to the water outlet channel 7 can be closed by a magnetic valve 73, which has a valve housing 731, in which a stationary magnet part 732 and a valve anchor 733, which can be adjusted, are arranged. The transition to the leaching of calcareous water from the evaporation vessel 2 is opened, otherwise it normally remains closed.

The configuration of the impeller 4 is best from the Fig. 2 and 3 seen. It comprises a smaller hollow-cylinder-like basic body 42 which is arranged on a larger hollow-cylindrical base body 43. From the smaller hollow cylinder-like base body 42, four wings 41 extend radially outwardly, which are located substantially inside the funnel-shaped part 5 and produce a main vortex in operation, which keeps the lime particles in the evaporation vessel 2 small and in suspension and for a good flow around the heater. 3 provides. From the larger hollow cylinder-like base body 43, four wings 45 extend radially outside, which are located substantially below the funnel-shaped part 5 in the water outlet side part of the water outlet 22 and keep the water in the water outlet side part of the water outlet 22 in motion.

The smaller hollow cylinder-like base body 42 surrounds a mounting cylinder 225 projecting upwards from the drain housing bottom 224 into which a screw 47 is screwed, which takes over the rotational support of the impeller 4, i. preventing removal of the impeller 4 from the drain casing bottom 224 without substantially hindering rotation of the impeller 4. The impeller 4 is also usually on four below the wings 45 on the hollow cylinder-like base body 43 formed feet 48 on the drain housing floor 224 on.

The larger hollow cylinder-like base body 43 surrounds a hollow cylindrical elevation in the middle of the drain housing bottom 224. It also has a plurality of recesses 44, in each of which a permanent magnet 46 is arranged. This forms the Flügelradseitigen part of a radially acting magnetic coupling for transmitting the driving force from a drive 8 to the impeller 4. The drive 8 comprises a motor 81 with a drive shaft 82, at the upper end of a magnetic drum 84 is fixed, which has recesses 85, in each of which a permanent magnet 83 is arranged. The magnetic drum 84 is located in the hollow cylindrical elevation in the middle of the drain housing bottom 224 and drives the impeller 4 upon rotation via the permanent magnets 83 and 46. A cooling fan acting as a fan wheel 86, which is mounted directly on the motor drive shaft 82, provides for the cooling of the motor 81st

Fig. 5 shows the lower part of the steam generator 1 with a separation device for separating water and lime in the form of a settling tank 9. The settling tank 9 is essentially a water vessel with three by two partitions 91 and 92 separate Gefässteilen 93, 94 and 95 and a Wasserauslassöffnung 96th The lime-containing water desludged from the evaporation vessel 2 passes via the water outlet channel 7 and a water outlet opening 74 into the first vessel part 93 and fills it until the water overflows the intermediate wall 91 into the second vessel part 94. If the second vessel part 94 is filled, the water flows over the intermediate wall 92 into the third vessel part 95 and fills it up to the water outlet opening 96. From the water outlet opening 96, the water finally reaches the pipeline network. In the three vats 93, 94 and 95, the lime particles can settle and are thus separated from the overflowing water. From time to time the settling tank 9 must either be cleaned or replaced.

In the 6 and 7 an alternative separation device for the separation of water and lime in the form of a filter device 109 is shown. The filter device 109 essentially comprises a water-permeable filter bag 191, which is attached to a Wasserzuführscheibe 192. The Wasserzuführscheibe 192 is on a shoulder 1931 of an otherwise substantially cylindrical container 193 removably on. It has an inlet opening 1921 and a feed channel 1922, via which lime-containing water from the water outlet channel 7 and the water outlet opening 74 is fed to the filter bag 191. The filter bag 191 passes the water and holds the lime back. He must therefore from time to time Time to be replaced. A grid disk 194 resting on an inner ring projection 1932 of the container 193 ensures that no large parts enter the container outlet 1933 when the filter bag 191 is inadvertently loosened.

In Fig. 8 a section of a second embodiment of an inventive steam generator 101 is shown. The only difference to the first embodiment is in the impeller 104, the in Fig. 9 is still shown separately. In contrast to the impeller 4 extend the impeller 104 from the larger hollow cylinder-like body 143 no wings to the outside. In addition, feet are missing on the underside of the main body 143. Finally, the permanent magnets are cast into the main body 143. Otherwise, the impeller 104 corresponds to the impeller 4 of the first embodiment. In particular, four wings 141, which are located substantially inside the funnel-shaped part 5, extend radially outward from a smaller, hollow-cylinder-like base body 142.

Fig. 10 shows a section of a steam generator 201 according to the invention according to a third embodiment. The difference from the first embodiment is that the impeller 204 is not driven by a magnetic coupling, but is directly mechanically connected to the drive shaft 282 of the motor 281. The drive shaft 282 is guided for this purpose through the drain housing bottom 290, wherein an annular shaft seal 291 provides a seal. Due to the mechanical connection of drive shaft 282 and impeller 204 can be dispensed with a magnetic drum and the arrangement of permanent magnets in the impeller 204.

The impeller 204 comprises for this purpose from bottom to top extending cylindrical central portion 242, in which the drive shaft 282 is inserted. From the upper half of the cylindrical central part 242, four wings 241 extend radially outwards, which are located substantially inside the funnel-shaped part 5. From each of these four wings 241, a further wing 245 extends obliquely downwards and outwards. These four wings 245 are located below the funnel-shaped part 5 in the water outlet side part of the water outlet and keep the local water in motion.

Otherwise, the steam generator 201 corresponds to the steam generator 1 of the first embodiment.

In a steam generator 301 according to the invention according to a fourth embodiment, of which in Fig. 11 1, the water outlet passage 307 is directly below the impeller 304. To enable such an arrangement, the magnetic drum 384 of the drive is located outside of the water drain 322 around it and the impeller 304 is disposed with the permanent magnets and vanes 341 around. For closing the water outlet 322, a solenoid valve 373 is arranged in this.

Fig. 12 shows as an alternative to an impeller a swirling device in the form of a worm wheel 404, while in Fig. 13 a swirling device in the form of a wobble plate 504 is shown.

Another alternative swirler in the form of a swirler 604 is shown in FIG Fig. 14 shown. The swirler 604 comprises a plurality of curved blades 641, the ends of which are screwed to a base disk 642.

To the steam generators described above, further constructive variations can be realized within the scope of the claims.

Claims (12)

1. Steam generator (1; 101; 201; 301) with an evaporation vessel (2) having a bottom (21) and a water outflow (22; 322), with a heating device (3) arranged in the evaporation vessel (2), and with a swirling device (4; 104; 204; 304; 404; 504; 604) arranged in the evaporation vessel (2) beneath the heating device (3), characterized in that the water outflow (22; 322) is arranged in the bottom (21) of the evaporation vessel (2), and the swirling device (4; 104; 204; 304; 404; 505; 604) is arranged partially in and partially vertically above the water outflow (22; 322).
2. Steam generator (1; 101; 201; 301) with an evaporation vessel (2) having a bottom (21) and a water outflow (22; 322), with a heating device (3) arranged in the evaporation vessel (2), and with a swirling device (4; 104; 204; 304; 404; 504; 604) arranged in the evaporation vessel (2) beneath the heating device (3), characterized in that the water outflow (22; 322) is arranged in the bottom (21) of the evaporation vessel (2), and the swirling device (4; 104; 204; 304; 404; 504; 604) is arranged completely in the water outflow (22; 322).
3. Steam generator (1; 101; 201; 301) according to claim 1 or 2, characterized in that the water outflow (22; 322) is arranged centrically in the bottom (21) of the evaporation vessel (2).
4. Steam generator (1; 101; 201; 301) according to one of claims 1 to 3, characterized in that the bottom (21) of the evaporation vessel (2) is of funnel-shaped design.
5. Steam generator (1; 101; 201; 301) according to one of claims 1 to 4, characterized in that the water outflow (22; 322) has arranged in it a funnel-shaped part (5), into which the swirling device (4; 104; 204; 304; 404; 504; 604) projects from below.
6. Steam generator (1; 101; 201; 301) according to claim 5, characterized in that the funnel-shaped part (5) is of sieve-like design and subdivides the water outflow (22; 322) into an evaporation vessel-side part and a water outlet-side part.
7. Steam generator (1; 101; 201; 301) according to one of claims 1 to 6, characterized in that the drive of the swirling device (4; 104; 304; 404; 504; 604) takes place via a radially acting magnetic clutch (46, 83; 384).
8. Steam generator (1; 101; 201; 301) according to one of claims 1 to 7, characterized in that the swirling device is an impeller (4; 104; 204; 304).
9. Steam generator (1; 201) according to claim 8, characterized in that the impeller (4; 204) has blades (41; 241) which are located essentially within the funnel-shaped part (5), and also blades (45; 245) which are located essentially beneath the funnel-shaped part (5) in the water outlet-side part of the water outflow (22).
10. Steam generator according to one of claims 1 to 7, characterized in that the swirling device is a worm wheel (404), a swash plate (504) or a swirler (604) having a plurality of lamellae (641).
11. Steam generator (1; 101; 201; 301) according to one of claims 1 to 10, characterized in that, for the outflow water flowing out from the water outflow (22; 322), it has a separation device (9; 109) for the separation of water and lime.
12. Steam generator (1; 101; 201; 301) according to one of claims 1 to 11, characterized in that the heating device (3) comprises at least two electrodes (31) or at least one resistance heating element.

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