DE2407645A1 - HEATING EQUIPMENT USING STEAM AS A HEATING MEDIUM - Google Patents

Description

Sa 2764

1. Nobuhisa Kodaira, Tokyo-to, Japan

2. Mikio Kusunose, Tokyo-to, Japan

Heating device with steam as the heating medium

The invention relates to a heater for heating 'gas, liquid and synthetic fiber yarn on the outside of a Liquid-vapor mixture or wet steam containing container.

Conventional, heating fluid using heaters are constructed so that a container in an upper vapor chamber and in a Heating fluid chamber is divided and that a heating source is provided inside or outside the heating chamber, whereby the heating liquid for feeding the steam chamber is heated to steam will. The heating surface is part of the steam chamber through which Superheated steam exchanging heat with the object to be heated

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and through which the generated condensate flows down the heating surface and thus returns to the heating liquid chamber.

When the heating fluid has been turned into steam, it rises The temperature of the heating fluid is also extremely high on if the amount of heat at the contact surface of the heating fluid with the heating source is extremely high. this causes dissolution or deterioration of the heating fluid. Also to enlarge the contact area of the heating source with the Heating fluid the volume of the heating fluid should be increased. This leads to a higher level of heating fluid and therefore to a smaller space in the steam chamber. Thus, the heating surface comes close to the object to be heated. It it also follows that the greater the depth of the heating fluid, the more the natural convection area increases, compared with the steam room above. This is therefore unsuitable if it cannot be preferred to prevent the heat transfer in the To cause boiling. Furthermore, when the heat exchange between the heating source and the heating fluid by natural convection is caused, even when a large amount of heat is supplied, it is difficult to evaporate as compared with the case when the Heat exchange is carried out by conduction.

It is the object of the present invention to obviate the disadvantages of the prior art and to provide an improved one To create a heater in which the vapor condensate of the liquid is conveyed through a drain and in the form of a film is guided onto the heating surface, whereby the heating liquid evaporates directly by conduction instead of convection , whereby the evaporation efficiency is greatly increased.

Another object of the present invention is to provide an improved heating device in which overheating of the heating liquid is avoided and the heat exchange surface with a relatively small amount of heating liquid avoids a large amount of heat is fed.

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Another object of the present invention is to provide an improved heater in which the level of the heating fluid is low and therefore the heat exchange area is so large it becomes that the heat exchange efficiency is greatly increased.

In order to achieve these objects, the container of the present invention having a heat exchange surface or a connection to a heat exchange unit is filled with a rather small amount of heating liquid and a steam chamber is formed over it. A heating element having a steam heating surface is provided in the steam chamber or is extended towards the steam chamber by the heating fluid. Between the heat exchange area of the inner wall of the container and the steam heating surface of the heating element sj ^ _r | l ^^ ensatabf 1 üsse provided, whereby the condensate generated on the heat exchange is delivered through drain distributors in the form of a film to the steam heating surface of the heating element. The steam heating surface of the heating member is heated by the heating source.

Other features, details and objects of the present invention result from the following description of exemplary embodiments with reference to the drawing. It shows:

Fig. 1 is a longitudinal section of the container of an embodiment of the present invention;

FIG. 2 shows a section along the line II-II in FIG. 1;

3 shows a longitudinal section of the container of a further embodiment of the present invention; ,

4 shows a longitudinal section of the container of a further embodiment;

Fig. 5 is an enlarged section of the essential part of the container of the present invention;

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Fig. 6 is an explanatory section of a steam heating surface of the heating member.

In Figs. 1 and 2, a closed container has 1 on its inner wall Heat exchange surfaces 2, 3, 4 and 5. In the middle of the container 1, an upright steam heating member 6 extends from the Bottom plate 11 of the container. The major part of the heating element stands freely in the steam chamber 7, as described below. A heating source 8, such as an electric heating wire, is enclosed in the heating element 6. The bottom of the container 1 is with a A fairly small amount of a liquid 9 is filled, while the space above the liquid forms the vapor chamber 7. Condensate drain manifold 10 extend from the heat exchange surfaces 2, 3, 4, 5 of the inner wall of the container to the heating element 6 down. One or more stacks of such drain manifolds 10 are provided distributed vertically at a distance from one another. The drain manifolds 10 are provided with a restriction, a fabric, a net made of heat-resistant material with perforations which allow capillary action of the steam.

The lower ends of the manifolds 10 can be connected to the heating surface of the heating member 6 or via a space with the heating member 6, see FIG. 5.

In the drawing, an arrow A indicates the direction of flow the heating fluid and an arrow B the direction of flow of the Drain.

To describe the mode of operation of the present device, the steam heating surface 6 is provided by the electrical heating source 8 and is at the beginning of the process, the heating fluid 9 through the Steam heating surface 6 heated. The liquid then transforms in heating steam and flows upwards in the direction of arrow A to the heat exchange surfaces 2 to 5 of the inner wall of the container to heat. After a certain time, the condensate formed on the heat exchange surfaces 2 to 5 of the inner wall flows up

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the drain manifold 10 to the surface of the steam heating surface down, see Fig. 5. The condensate thus forms a film (0.1 - 0.3 mm thick) on the steam heating surface of the link 7. This heating liquid can easily be evaporated again thanks to the im In contrast to convection, the rapid heat conduction present here. Since the distance t from. the. Heating surface 6 to the surface of the heating fluid is as thin as a film, the heat transfer to Liquid surface is caused by conduction instead of convection, which causes evaporation of the liquid immediately from the surface of the film, see Fig. 6. Compared with the boiling state, the heater of the present Invention improve the evaporation efficiency with respect to a given amount of heat. The heating fluid is consequently too exposed to lower fluid pressure and evaporates quickly from it, which means it never overheats. Furthermore, since the Drain manifold 10 with a heat-resistant material with small Through holes is covered, the condensate is caught in a continuous stream and forms a film over the Steam heating surface 6.

In the embodiment shown in Fig. 3, the container is in

a chamber with a heating element having a steam heating surface 6 member and / a steam exchange surface to be heated by heating steam 2, 4 having chamber divided. These chambers are connected to one another by a connecting pipe 12. One end of the drain manifold 10 is connected to the heat exchange surfaces 2 4 of the inner wall and the other end of the distributor with the steam heating surface 6 tied together. The steam chamber 7, the heating source 8 and the base plate 11 are shown in FIG. 3. The arrow A gives the Direction of the heating steam, while the arrow B indicates the direction of the outflow. That on the heat exchange surfaces of the The condensate formed on the inner wall flows through the discharge manifold 10 down and is supplied around the steam heating surface 6 to to form a film. The other functions are the same as those of the device shown in FIG.

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Another embodiment is shown in Fig. 4, in which the Steam heating surface 6 is formed on the inner wall of the container 1 The reference numeral 13 denotes a heating source for the heating liquid 9. The other components are the same as those shown in FIG. At the beginning of operation, the heating fluid is 9 heated by the heating source 13. Thereafter, the condensate formed on the heat exchange surfaces is drained through a manifold 10 supplied to the steam heating surface of the heating element.

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Claims (4)

Claims Heating device with steam as heating medium, characterized by a container filled with liquid, through a heating member with a steam heating surface in its lower part and with heat exchange surfaces in its upper part, and through condensate drain manifolds for supplying onto the heat exchange surfaces formed condensate to the steam heating surface, whereby the condensate is delivered by gravity in the form of a film onto the steam heating surface. 2. heater with steam as heating means according to claim 1, characterized characterized in that the drain manifolds are made of a heat-resistant material with perforations for admitting a Capillary action are covered. 3. Heater with a liquid-vapor mixture as the heating medium according to claim 1, characterized in that the lower part of the heating member is immersed in the liquid, and that the upper part of the heating member exposed to the steam chamber is. 4. Heater with a liquid-vapor mixture as the heating means according to claim 1, characterized in that the container in a chamber which is provided with a heating element having a steam heating surface, and is divided into a chamber with heat exchange surfaces, the chambers with a Connection pipe are connected. 409882/0285 Leeward