WO2006097002A2

WO2006097002A2 - Steam generator comprising a swirling device

Info

Publication number: WO2006097002A2
Application number: PCT/CH2006/000137
Authority: WO
Inventors: Andrzej Szpilski; André GEROLD; Daniel Dietziker
Original assignee: Axair Ag
Priority date: 2005-03-14
Filing date: 2006-03-03
Publication date: 2006-09-21
Also published as: EP1859200A2; CA2601633C; WO2006097002A3; EP1859200B1; CA2601633A1; US20080279539A1

Abstract

The invention relates to a steam generator (1) comprising an evaporation tank (2) which is provided with a base (21) and a water outlet (22). A heating device (3) is arranged in said evaporation tank (2) and an impeller (4) is arranged under said heating device (3), as a swirling device. The water outlet (22) is arranged in the base (21) of the evaporation tank (2) and the impeller (4) is arranged in the water outlet (22). Due to the inventive arrangement of the water outlet (22) and the impeller (4), which rotates in an essentially continuous manner when in operation, a whirl is produced in the water of the evaporation tank (2) and, in particular, in the water outlet (22). As a result, limescale which is present in the water, in particular, in the region of the water outlet (22) is continuously displaced and maintained in suspension in small particle sizes.

Description

Steam generator with swirling device

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 treated with a heating device, such as Electrodes or electrical resistors, heated and evaporated, wherein mineral salts are precipitated, which are removed from the evaporation vessel from time to time by slurrying. For this purpose, the evaporation vessel has a water outlet, which is arranged, for example, in a steam generator disclosed in US Pat. No. 4,221,955, 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.

In the steam generator disclosed in US Pat. No. 4,221,955, although an impeller arranged above the evaporation vessel bottom reduces the sedimentation of lime as a turbulizer, this is just as little prevented as the calcination of the water drainage. The impeller is not used for this purpose, but to increase the steam without adding more water. This increase in steam output is due to the fact that, as the impeller rotates, the water surface is conically deformed in a spiral shape, 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 sedimentation KaIk- 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 evaporating vessel, so that its calcification is not prevented.

In view of the problem of the rapid necessity of certain types of water for a costly cleaning of the steam generator due to the calcification of the water flow and sedimentation of lime in the steam generators known hitherto, the object of the invention is to provide a steam generator of the type mentioned in the beginning, in which less often ^{• an} expensive decalcification with associated steam generator downtime must be performed.

This object is achieved by the inventive steam generator, as defined in independent claim 1. 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. In the evaporation tank are ^■ heating and below the heater a swirling arranged lungeinrichtung. According to the invention, the water outlet in the bottom of the evaporation vessel and the swirling device are arranged in and / or vertically above 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 especially in the range of

Water drain constantly moved and held in small particle size in suspension. At the same time, the part of the heating device submerged in the water is also circulated through water at a relatively high velocity, which also counteracts calcium deposits.

By keeping the lime in limbo, the growth of large lime crystals can be prevented and less lime sediments on the bottom of the vat. 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.

Preferably, in the inventive steam generator, the

Whirling completely arranged in the water outlet. This results in an optimal for the blow-suction effect and can also calcification of Wasserab- ^• run are virtually eliminated.

Advantageously, the .Wasserablauf is arranged centrally in the bottom of the evaporation vessel. This allows for optimal Blasting and, together with a centric arrangement of the turbulizer, results in optimum formation of the water vortex created during operation, which thus ideally captures the entire water present in the evaporation vessel.

Preferably, the bottom of the evaporation vessel is funnel-shaped. This leads on the one hand to a diversion of the vortex energy generated by the swirling device mainly in the direction of. Heating and ensuring. so their intensive flow around. 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 turbulizer can be directed in a more targeted manner in the direction of the heating device.

Advantageously, the funnel-shaped portion is formed like a sieve, and dividing the water flow into a rate of evaporation ^• fässseitigen portion and a water outlet-portion. 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 Verwirbe- A device impeller. Such an impeller generates an optimal vortex with a simple structure.

Advantageously, the impeller has vanes which are located substantially inside the funnel-shaped part and vanes which are located substantially below the funnel-shaped part in the water outlet-side part of the water outflow. With such a double-decker impeller, on the one hand, a main vortex can be generated which keeps the caustic particles in the evaporation vessel small and in limbo and ensures a good flow around the heating device. At the- . At the same time, this allows the water in the water outlet part of the water outlet, via which it can be slurried or supplied to the water, to be kept in intensive motion.

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

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, there is no danger that a swirling device blocked by calcification, for example, simultaneously blocks the engine, which could damage it. 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.

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

1 shows a first embodiment of a steam generator according to the invention in a partially sectioned perspective view;

Fig. 2 - is a sectional view of a ^'lower part of the steam generator of FIG. 1;

Fig. 3 is an exploded view of the impeller, the water drain and the impeller drive of the steam generator of Fig. 1;

FIG. 4 shows the steam generator parts of FIG. 3 in assembled form in a partially cut-away perspective view; FIG. Fig. 5 - a lower part of the steam generator of Figure 1 with a separation device in the form of a settling tank in a partially sectioned perspective view ..;

FIG. 6 shows 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.

Fig. 7 - the lower part of the steam generator with filter device of Figure 6 in a sectional view.

8 shows a sectional view of a lower part of a steam generator according to the invention in accordance with a second exemplary embodiment;

Fig. 9 - the impeller of the steam generator of Fig. 8;

10 shows a sectional view of a lower part of a steam generator according to the invention without a magnetic coupling according to a third exemplary embodiment;

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

FIG. 12 shows a swirling device in the form of a worm wheel; FIG.

Fig. 13 - a swirling device in the form of a wobble plate; and FIG. 14 shows a swirling device in the form of a swirler having a plurality of lamellae. FIG.

In the first exemplary embodiment illustrated in FIGS. 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 includes a plurality of fixed to the ceiling 24 electrodes 31 having power connectors 311, which project through the ceiling 24 through the outside.

Centrally in the bottom 21 of the evaporation vessel 2, a water drain 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 of a sieve-like design and subdivides the water outlet 22 into an evaporation-vessel-side part and a water-outlet-side part. It is supported by a Cylinder 51 is supported, which rests on the drain housing bottom 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 armature 733 adjustable for this purpose are arranged. The transition to the leaching of calcareous water from the evaporation vessel 2 is opened, otherwise it normally remains closed.

The design of the impeller 4 is best seen in FIGS. 2 and 3. It comprises a smaller, hollow-cylinder-like basic body 42, which is arranged on a larger, hollow-cylinder-like basic body 43. From the smaller hollow cylinder-like base body 42, four wings 41 extend radially outward, 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 Heating device 3 ensures. From the larger hollow cylinder-like base 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 obstructing 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 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, when rotating via the permanent magnets 83 and 46, drives the impeller 4. 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 the separation of 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 95th and a water outlet opening 96. The lime-containing water drained 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 vessel parts '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.

FIGS. 6 and 7 show an alternative separation device for separating water and lime in the form of a filter device 109. The filter device 109 essentially comprises a water-permeable filter bag 191, which is fastened to a water supply disk 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 are 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.

FIG. 8 shows a detail of a second exemplary embodiment of a steam generator 101 according to the invention. The only difference from the first embodiment is the impeller 104, which is shown separately in FIG. 9. In contrast to the impeller 4 extend the impeller 104 from the larger hollow cylinder-like base 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.

10 shows a section of a steam generator 201 according to the invention in accordance with a third exemplary 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 central cylindrical 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 of the water outlet and keep the water there 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 in accordance with a fourth exemplary embodiment, of which a part is shown schematically in FIG. 11, the water outlet duct 307 is located directly below the impeller 304. To enable such an arrangement, the magnetic drum 384 of the drive is outside the Water drain 322 arranged around this and the impeller 304 with the permanent magnets and the wings 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 FIG. 13 shows a swirling device in the form of a pulley 504. Another alternative swirling device in the form of a swirler 604 is shown in FIG. 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

claims

1. Steam generator (1; 101; 201; 301) with a vaporization vessel (2) having a bottom (21) and a water outlet (22; 322), a heating device (3) arranged in the evaporation vessel (2) and one in the evaporation vessel (2) swirling device (4; 104; 204; 304; 404; 504; 604) arranged below the heating device (3), characterized in that the water outlet (22; 322) in the bottom (21) of the evaporation vessel (3) 2) and the swirling device (4; 104; 204; 304; 404; 504; 604) is arranged in and / or vertically above the water outlet (22; 322).

2. Steam generator (1; 101; 201; 301) according to claim 1, characterized in that the swirling device (4; 104; 204; 304; 404; 504; 604) is arranged completely in the water outlet (22; 322).

3. Steam generator (1; 101; 201; 301) according to claim 1 or 2, characterized in that the water outlet (22; 322) is arranged centrally 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 funnel-shaped.

5. Steam generator (1, 101, 201, 301) according to one of

Claims 1 to 4, characterized in that a funnel-shaped part (5) is arranged in the water outlet ^• (22; 322) into which the swirling device (4; 104; 204; 304; 404; 504; 604) protrudes from below.

6. steam generator (1; 101; 201; 301) according to claim 5, characterized in that the funnel-shaped part (5) is sieve-like and the water outlet (22; 322) divided into a evaporation vessel side part and a water outlet side part.

7. Steam generator (1, 101, 301) according to any one of claims 1 to 6, characterized in that the drive of the

Vortexing device (4; 104; 304; 404; 504; 604) via a radially acting magnetic coupling (46, 83, 384) takes place.

8. Steam generator (1; 101; 201; 301) according to one of claims 1 to 7, characterized in that the turbulizer is an impeller (4; 104; 204; 304).

9. Steam generator (1, 201) according to claims 6 and

8, characterized in that the impeller (4; 204) comprises vanes (41; 241) located substantially inside the funnel-shaped part (5) and vanes (45; 245) extending substantially below the funnel-shaped part (5) located in the water outlet side of the water drain (22).

10. Steam generator according to one of claims 1 to 7, characterized in that the swirling device is a worm wheel (404), a wobble plate (504) or a plurality of lamellae (641) having Verwirbler (604).

11. A steam generator (1, 101, 201, 301) according to one of claims 1 to 10, characterized in that it has a separation device (9, 109) for the separation of water and lime for the discharge water draining from the water outlet (22; 322) ,

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.