EP0685682A1

EP0685682A1 - Steam generating boiler

Info

Publication number: EP0685682A1
Application number: EP95201356A
Authority: EP
Inventors: Virgilio Guzzini
Original assignee: Teuco Guzzini SpA
Current assignee: Teuco Guzzini SpA
Priority date: 1994-06-01
Filing date: 1995-05-23
Publication date: 1995-12-06
Also published as: ITMI941132A0; IT1269878B; ITMI941132A1

Abstract

A boiler for generating steam is composed of a vessel (12) for containing water to be brought to boiling point, a first pipe connection (24) for incoming water in the liquid state, a second pipe connection (28) for outgoing steam and a heating element (34) to bring the water to boiling point. The vessel (12) is divided by a partition wall (14) into a first sector (16) containing the heating element (34) and a second sector (18) containing the inlet (24) and outlet (28) pipe connections. The sectors (16, 18) communicate with each other through a first (20) and a second (22) aperture in the partition wall (14), disposed respectively below and above the free surface (32) of the water.

Description

This invention refers to a boiler for generating steam, for example for sauna installations.
In the technology of generating steam for the health and well-being of the body, use is made of boilers composed of an airtight vessel filled with water which is heated to boiling temperature by an electric heating element immersed therein.
The steam thus produced is made to escape from a duct opening out on the upper part of the boiler, and conveyed to the outlet nozzles of the system.
The level of the water in the boiler can usually be measured by means of a sensor floating on the free surface of the water, which constitutes a simple and inexpensive level indicator.
For use in modern sauna installations, such as sauna-shower baths, the dimensions of the boiler must be extremely limited (generally 1-2 litres) due to problems of available space, as well as to the need to obtain short heating periods.
Boilers of such limited dimensions, however, have various drawbacks, such as the drawback deriving from the fact that the steam flowing into the outlet duct tends to entrain a relatively large quantity of hot water, which is emitted from the nozzles together with the steam itself, causing the sauna installation to operate unsatisfactorily.
Moreover, due to the limited dimensions of the boiler and the high vaporization speed required, the turbulence of the water is considerable and such as to give rise to instability of the floating sensor resulting in difficulty in measuring the exact level of the fluid, in addition to increasing the quantity of water entrained by the steam. The general scope of this invention is to obviate the aforementioned problems by providing a boiler which, although having limited dimensions and a high vaporizing speed, supplies steam with a limited condensed water content and, moreover, enables precise measurement of the fluid inside it.
This scope is achieved, according to the invention, by providing a boiler for generating steam, in particular for sauna installations, comprising a vessel for containing water to be brought to boiling point, having a first pipe connection for incoming water in the liquid state and a second pipe connection for outgoing steam and containing a heating element to bring the water to boiling point, characterized by the fact that the vessel is divided by a partition wall into a first sector containing the heating element and a second sector containing the inlet and outlet pipe connections, said sectors communicating with each other through a first and a second aperture in the partition wall, disposed respectively below and above the free surface of the water.
The innovative principles of this invention and its advantages with respect to the known technique will be more clearly evident from the following description of a possible exemplificative embodiment applying such principles, with reference to the accompanying drawings, in which:

Fig. 1 shows a cross-sectional view of a boiler according to the invention.

With reference to the drawing, Fig. 1 shows a boiler 10 for generating steam, consisting of a superiorly, inferiorly and laterally closed vessel 12.
The vessel 12, generically of relatively limited dimensions (1-2 litres), is divided by a partition wall 14 into two sectors 16, 18, communicating with each other by means of apertures 20, 22 situated respectively in the lower part and in the upper part of the wall 14.
Close to the lower end of sector 18 is a pipe connection 24 for incoming cold water from a supply duct 26. Close to the upper end of the same sector 18 is a pipe connection 28 for outgoing steam produced by the boiler, connected to a feed duct 30 feeding steam to nozzles of known technique, in particular belonging to a sauna installation.
Advantageously, the outlet pipe connection 28 is situated in a chamber 40 above the sector 18, so as to be spaced at a distance from the upper aperture 22 in the wall 14 and at a greater height than the latter.
The water introduced into the boiler through the pipe connection 24 fills the two sectors 16, 18 of the vessel 12 passing through the lower aperture 20 in the partition wall 14, up to a level 32 lower than the height of the upper aperture 22 in the same wall 14.
Disposed inside the sector 16 is a heating element, advantageously composed of an electric resistor 34 of known characteristics and consequently not described in detail. The resistor 34 is positioned inside the sector 16 so as to remain submerged in the water while the boiler is in operation.
Housed inside the sector 18 is a sensor element 36 which senses the level of the free surface 32 of the water in the boiler. Said sensor element is advantageously of the known floating type.
The sensor 36 emits an output signal to command for example the introduction of water into the boiler so that, when the boiler is in operation, the water enters the vessel 12 through the pipe connection 24 at such a rate as to compensate for the quantity of steam escaping through the pipe connection 28, maintaining the free surface 32 of the water inside the boiler at a substantially constant level. Moreover, the sensor 36 can act as a safety system, switching off the boiler whenever the level of the fluid drops below the minimum safety value.
The sector 16 can also contain a temperature sensor 42 to detect and control the water heating temperature.
The heating element 34 brings the water to boiling point, with generation of steam Consequently, the water contained in sector 16 is subject to intense turbulent motions.
The steam produced is conveyed upwards by convection towards the upper end of the sector 16, and out of the latter through the aperture 22 in the wall 14. In order to reach the outlet pipe connection 28, it now has to travel along a path, indicated by the arrows 38 in Fig. 1, situated above the free surface of the water inside the sector 18.
When the steam leaves the surface of the boiling water it entrains, as mentioned previously, a certain quantity of drops of water in the liquid state which, if they were to reach the nozzles of the installation, would cause it to operate unsatisfactorily. In the boiler according to the invention, the partition wall 14 delimits the sector 16 where the steam is formed, forcing the latter to travel along the suitably dimensioned path 38, along which the aforesaid drops of water fall back into the water inside the sector 18, so as to enable substantially pure steam to be emitted from the pipe connection 28.
The presence of the chamber 40 increases the length of the path used for precipitation of the drops of water from the mass of steam.
Since the cold water inlet is disposed in chamber 18, said chamber has a lower temperature than chamber 16.
As mentioned previously, the water contained in sector 18 is free from turbulence, consequently the floating sensor positioned in such sector provides precise data as to the level of the water in the boiler, since it is not affected by the turbulence produced by the heating element.
It is clear that the intended scopes are achieved by providing a boiler according to the invention.
The foregoing description of an embodiment applying the innovative principles of this invention is obviously given by way of example in order to illustrate such innovative principles and should not therefore be understood as a limitation to the sphere of the invention claimed herein.
For example, the disposition of the various elements, such as the water inlet and steam outlet pipe connections, can be different from the one shown in the figure.
Moreover, the conformation and positioning of the partition wall 14, as well as its apertures 20, 22, can differ from those described, as can the general shape of the watertight vessel 12.

Claims

Boiler for generating steam, in particular for sauna installations, comprising a vessel (12) for containing water to be brought to boiling point, having a first pipe connection (24) for incoming water in the liquid state and a second pipe connection (28) for outgoing steam and containing a heating element (34) to bring the water to boiling point, characterized by the fact that the vessel (12) is divided by a partition wall (14) into a first sector (16) containing the heating element (34) and a second sector (18) containing the inlet (24) and outlet (28) pipe connections, said sectors (16, 18) communicating with each other through a first (20) and a second (22) aperture in the partition wall (14), disposed respectively below and above the free surface (32) of the water.
Boiler as claimed in claim 1, characterized by the fact that disposed inside the second sector (18) is a sensor (36) for measuring the level (32) of the water in the boiler.
Boiler as claimed in claim 1, characterized by the fact that the steam outlet pipe connection (28) is disposed above the second sector (18), at a distance from the aperture (22) between the two sectors which is situated above the free surface (32) of the water, preferably at a greater height than said aperture.
Boiler as claimed in claim 1, characterized by the fact that the heating element (34) consists of an electric resistor.
Boiler as claimed in claim 2, characterized by the fact that the sensor (36) is a floating sensor.
Boiler as claimed in claim 3, characterized by the fact that the outlet pipe connection (28) is disposed close to the upper portion of a chamber (40) which is an upper extension of the second sector (18).