CS209126B1 - Partitions for tube bundle bundles - Google Patents

Abstract

The invention solves the problem of creating new partitions for tube bundles of tube apparatuses, which can ensure minimal pressure loss and optimal heat transfer coefficient. The partitions according to the invention are formed by segments that create at least one interrupted or continuous helical surface in the intertube space. The segments can be made in various variants, in particular as circular sectors, flat or shaped. However, other designs of the segments are possible. However, these segments always form a continuous or interrupted helical surface after assembly. The invention can be applied both to classic tube exchangers with a bundle of tubes placed in a shell, and to tube-in-tube type exchangers, or to other types of tube exchangers, e.g. in evaporators, reactors, etc.

Description

(54) Bulkheads for tube bundles

The invention solves a new design of baffles for pipe tubes of tubular apparatuses, which find a minimum pressure drop and an optimal heat transfer coefficient.

The baffles according to the invention are formed by segments which in the inter-tubular space create at least one intermittent Si continuous screw surface. The segments can be made in various variants, in particular as circular sectors, either planar or shaped. However, 1 other embodiments of the segments are possible. These segments, however, always form a continuous or intermittent screw surface after assembly.

The invention can be applied both to conventional tube bundle exchangers placed in the jacket and to tube-in-tube or tube-to-tube exchangers. also for other types of tube exchangers, eg evaporators, reactors, etc.

$ 20

BACKGROUND OF THE INVENTION The present invention relates to the provision of baffles for bundles of tubes.

Existing tubular apparatus designs use the most commonly planar transverse baffles to support tubular bundles. These baffles may be either segmented. or disc. In the first case, the segments may be formed on one side or on one side. In the latter case, the segments have the shape of a circular or annular surface, the surfaces being alternately arranged one after the other. The baffles described here not only provide support for the tubes of the tube bundle, but are also used 1 to form a channel for the medium flowing through the inter-tube space.

In technical practice, bar partitions are also occasionally used, which consist of inter-circular plates 8 welded with steel bars parallel to each other, the bars in the ee partitions alternating so. the tubes form a compact vibration-resistant bundle with low pressure loss. In this case, on the same blanket of the tube bundle, a plurality of baffles are required to support tubes, in some constructions up to four times the number of conventional baffles of segmental disc cells.

The first types of partitions, ie segment and disk partitions, have the advantage that by changing the size of their spacing and slots, the desired channel size can be adjusted, thus achieving optimum media speeds, respectively. However, these measures, in turn, result in considerable increases in pressure losses. Nevertheless, dead corners arise in the ditches in front of and from the bulkheads, which exclude a certain portion of the heat exchange surface from proper operation and also have a considerable effect on the intensity of fouling in these areas.

When using the second type of baffles, i.e. rod baffles, dead corners have been eliminated in some way and the pressure losses are greatly reduced, but it is not possible to influence the channel size given by the casing diameter. In addition, a new problem arises in terms of equalizing the inlet of the medium along the cross-section of the inter-tube space of the exchanger. In the best case, in the turbulent flow, and that it produces a velocity profile in the shape of a paraboloid to cone, in the laminar flow, the respective amount of medium flows only part of the inter-tube space.

A summary of the advantages of both types of the above-mentioned baffles, while at the same time eliminating all of its drawbacks, is made possible by forming baffles for the tubes of the pipe apparatus according to the invention, which consists of segments which create at least one continuous or intermittent helical surface.

The screw surface of the baffles allows not only perfect flushing of the apparatus, which helps to eliminate dead corners and reduce the tendency to clog, but at the same time allows the fluid to be transported smoothly through the inter-tube space of the apparatus without significant pressure losses. used counters. In addition, by varying the pitch of the bolt surface of the baffles, it is possible to influence the size of the flow channel and thus the heat transfer coefficient.

3e-11, such that the safe spacing of the pipe supports cannot be maintained, it is possible to provide the baffles so that, once assembled, the helical surfaces form two or more steps.

The baffles are formed by segments that can be either circular planar segments or shaped segments. Especially advantageous are the latter-shaped circular segments, which impart less resistance to the flowing medium through the inter-tube space than the plane segments, which results in less pressure loss.

Various other variants are also possible in the executed segments, such as segments formed by portions of a helical surface over a distance of half of the pitch, etc. It is important that such shaped segments always form a helical surface after assembly, either intermittently or where the bundle of tubes must be firmly supported, continuous.

Exemplary embodiments of baffles for tube bundles of tube apparatuses of the invention are schematically shown in the accompanying drawings, in which Fig. 1 is a longitudinal sectional view of a shell exchanger with a straight bundle of heat-pipe tubes;

In the exchanger housing 1 provided with fixed tubesheets 2, bundle tubes 3 (Fig. 1) are supported, supported by segments 4 in the form of planar barriers, which are arranged to form a helical surface with an incline s.

The segmental barriers of the tube bundle (Fig. 2) are connected to each other by means of flat bars 5 to which they are welded. The flat rods 5 parallel to the heat exchanger tubes 3 can also be used as a sealing for the bypass flows between the tube bundle and the jacket 1 of the exchanger.

In the case of exchangers of larger diameters, the segmental baffles can also be attached to the central tube 6, which does not fulfill the function of a heat exchange tube like the other tubes 3 of the tube bundle, but serves solely for fixing the separator baffles.

The invention can be applied to conventional tube bundle heat exchangers placed in the jacket, as well as to tube-in-tube or tube-type exchangers. also in other types of pipe apparatus, such as evaporators and reactors.

Claims (3)

BACKGROUND x Bulkheads for pipe bundles of tubular apparatuses, characterized in that they are formed by segments (4) which form at least one intermittent or continuous helical surface in the inter-tube space. Partitions according to claim 1, characterized in that the segments (4) are designed as planar circular segments. Partitions according to claim 1, characterized in that the segments (4) are designed as shaped sectors.