CS196552B1 - Apparatus for overheat protection of packings and/or bearings - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a device for protecting seals and bearings against overheating, in which a more uniform heat exchange and heat dissipation from locations subjected to overheating are solved using conventional construction materials.

In modern chemical technology, in particular in petrochemistry, the required course of the reaction is based on relatively accurate temperature maintenance in the reaction space. Of the major factors affecting heat transfer, the heat transfer coefficient can be influenced. In order to achieve the necessary heat transfer coefficients, it is necessary in the reaction space to ensure the movement of the reactants around the heat transfer surfaces, which exchange heat with the reaction space according to the type of reaction taking place in terms of its thermal coloration. The movement of the reactants around the heat transfer surfaces is ensured by different mixing methods, for example by means of different types of stirrers in batch reactors and scraper blades for film evaporators, rectifiers, etc. However, this movement is not very intense and often, especially for reactants with higher viscosity. local overheating. If such apparatuses operate with extreme reaction conditions (high temperatures, pressures, possibly vacuum), the choice of material causes the seals and bearings and their constructions, especially with high demands on corrosion resistance.

The prior art solutions solve this problem by cooling the bearings and / or plugs by means of a coolant circulation circuit or by passing cooling air through the hollow shaft with an auxiliary fan. Another design is to extend the bearing outside the area of overheating or corrosive effects, or upstream of the seal. All these designs are structurally demanding and cannot be used in all applications.

The object of the device for protecting seals or bearings of parts of apparatuses rotating around a vertical axis against overheating caused by heat transfer from the contact area of the seal or bearing with the surface of the rotating part of the apparatus to a seal or bearing containing a heat pipe with heat transfer medium is according to the invention. the axial evacuated cavity or cavity system is located at the location of the seal or bearing, in the support shaft or in the ring rigidly connected thereto, wherein the total volume of the cavity or cavity system is 20 to 40% filled with heat transfer medium. There may be a surface on the protruding portion of the support shaft to compensate for thermal gradients. In the case of the application of both independent systems within the support shaft and in a ring fixed thereto in the device according to the invention, a separate axial evacuated cavity or cavity system separating the two systems may be formed at the seal or bearing location.

19 <552

During operation, a set-exchange medium (ether, alcohol, sulfur, mercury, etc.), enclosed in an evacuated cavity or shaft-shaft cavity system, by heat in an endothermic reaction - from heating using, for example, electric, steam, water heater, or exothermic reaction - The heat of reaction heat evaporates and its vapors condense at any point of the cavity at a lower temperature, ensuring a uniform temperature and heat dissipation over the entire heat transfer surface.

The main advantages of the device according to the invention are as follows: more efficient and uniform heat exchange and heat dissipation from overheated areas by means of a rotating part with possible surface connection ensuring thermal gradients are compensated; improving the heat exchange process caused by accelerating the movement of the heat transfer medium around the surface to provide a thermal gradient; preventing the removal of useful heat from the system, particularly when applying the heating of the reaction space by means of a heat pipe; Possibility to use common construction materials such as teflon for seals and common construction materials for bearings.

Some possible embodiments of the device according to the invention are shown in the accompanying drawings, in FIGS. 1 and 2.

FIG. 1 shows a device according to the invention used for cooling the agitator shaft at the seal and bearings 2, e.g. in a KOH dissolving boiler, at a temperature of 270 ° C. A cavity 5 formed in the shaft 3, filled with 40% of the volume in this case with water as heat exchange medium 6, provides cooling of the shaft 3 and allows the use of teflon rings in the construction of the gland 1. In this case, the rotating air cooler 7 formed as part of the drive pulley connected to the upper end of the shaft 3 provides the necessary heat dissipation.

Fig. 2 shows a device according to the invention used to protect the seal and rotor bearing of a molecular evaporator, eg for separating and cleaning thermolabile substances requiring a higher temperature to evaporate. The heat energy source is the heat pipe inside the shaft. A system of evacuated cavities 5 filled with 30% by volume of heat transfer medium is used to cool the bearing and packing location 1. In order to reduce the load on this system, a further evacuated cavity system 8 is provided at the cooling point of the shaft 3, preventing heat conduction into the cooled part of the shaft 3.

At extreme temperatures, the rotary system needs to be cooled more efficiently at the point of seals and bearings, but it is also necessary to limit the transfer of useful heat from the system. More efficient cooling is provided by a second evacuated axial cavity or cavity system located in a ring fixedly connected to the support shaft, with a heat transfer medium charge that heats to boiling and condenses in a separate rotary heat exchanger, thereby providing cooling at these locations. To avoid useful heat or waste heat from the cooling system, this cooling system is separated from the first system, which operates at higher temperatures (in two possible types of thermal color reaction), by an evacuated space which limits heat transfer due to the known poor thermal conductivity between the two systems.

Claims (3)

SUBJECT OF THE INVENTION A device for protecting gaskets or bearings of parts of apparatus rotating about a vertical axis against overheating caused by heat transfer from a gland or bearing contact surface of a rotating part of the apparatus to a gland or bearing, comprising a heat transfer tube filled with heat transfer medium; the axial evacuated cavity or cavity system (5) is located at the location of the seal (1) or bearing (2), in the support shaft (3) or in the ring (4) fixed therewith, the total volume of the cavity or cavity system (5) it is 20 to 45% filled with heat transfer medium (6). Device according to claim 1, characterized in that on the protruding part of the support shaft (3) there is a surface (7) providing compensation for thermal gradients. Device according to claim 1 or 2, characterized in that there is a separate axial evacuated cavity or cavity system (8) separating the system in the ring (4) from the system inside the shaft (3) at the seal (1) or bearing (2).