GB2047313A - Structural components - Google Patents

Abstract

The present invention provides a laminar structural component comprising a series of profiled plates (1, 2, 3) assembled and secured together with each plate abutting the adjacent plate or plates at a plurality of zones to form a coherent structure. Such structures of 'honeycomb' cross section have many advantages over solid structures and are particularly applicable to the head and follower components of plate heat exchangers or evaporators. When such structures are required to be corrosion resistant or hygienic the use of a suitable solid material is likely to be prohibitively expensive and claddings using such materials are prone to failure. <IMAGE>

Description

SPECIFICATION Structural components This invention relates to laminar structural components.

Laminar structural components, which may be required to absorb distributed and/or point loadings, are normally of solid material e.g. mild steel plate, and therefore present machining, fabrication and handling difficulties. Also, when they are required to be corrosion resistant or hygienic, e.g. as parts of heat exchangers in the chemical and food industries, the use of solid stainless steel or titanium is likely to be prohibitively expensive and cladding of such a corrosive resistant material may not be a wholly satisfactory answer owing to the possibility of failure of the cladding.

The invention is particularly applicable to the structural components to form the head and follower of plate heat exchangers or evaporators and will be particularly described in that context, but its application is not so limited. The invention is also particularly applicable to curved laminar structural components.

According to a first aspect of the present invention, there is provided a laminar structural component comprising a series of profiled plates assembled and secured together with each plate abutting the adjacent plate or plates at a plurality of zones to form a coherent structure.

According to a second aspect of the invention, the component is a head or follower of a plate heat exchanger frame.

The plates of the series may be held together by welding, mechanical interlocking, clamping or a combination thereof.

The spaces between the plates of the series may be filled with a viscous liquid, such as a glue or resin. Alternatively, the spaces may be sealed and evacuated to assist in clamping between plates.

According to a third aspect of the invention, there is provided a plate heat exchanger including a head and/or follower according to the invention as set forth above.

By using a honeycomb structure of plates rather than solid structural members, the following advantages accrue, inter alia: 1) The component can be made from pressed thin sections and does not require any "heavy" machining operations; 2) If equivalent strength solid structures are greater than 3 inches (7.6 cm) thick then these can be susceptible to brittle fracture at freezing point.As the component is composed of relatively thin sections it will not suffer from this deficiency; 3) The bending strength to weight ratio of the component is significantly higher than the same strength solid flat plate or ribbed flat plate; 4) The modular method of construction enables each component to be designed to suit individual loading and geometry requirements; 5) If a component, when in a plate heat exchanger, is required to contain any holes then the compensation requirements to comply with pressure vessel codes will be less and more easily catered for than with the solid plate alternative; 6) Large flat or curved units can be easily assembled from the flexible flat modules; 7) The component does not suffer from welding distortions because of the absence of flange welds;; 8) The variety of design options available provides an infinite number of variations to be explored for each loading situation; and 9) As a result of the above the machine can be less expensive than the equivalent strength solid or ribbed plate alternatives, The invention will be further described with reference to the accompanying diagrammatic drawings, which illustrates various forms of the invention, and in which:: Figure 1 is a partial exploded view showing parts of a number of corrugated plates forming a part of a structure according to the invention; Figures 2, 3 and 4 show three possible methods of securing adjacent plates together; Figures 5, 6 and 7 illustrate possible arrangement of the ribs on adjacent plates; Figure 8 is a diagrammatic elevation, partly in section, to illustrate a form of head or follower according to the invention; Figure 9 is a partial elevation of a follower showing an attachment for tie bars; and Figures 10 and 11 are respectively a section and an elevation of an alternative form of tie bar attachment.

A component according to the invention may consist of any required number of plates in a series, but for simplicity of illustration, Figures 1 to 7 only show portions of two or three successive plates in the series. It is not envisaged that these numbers should have any limitative effect. In Figure 1 there are shown three plates 1, 2 and 3, of which plates 1 and 3 have the same orientation so that their corrugations are parallel with each other while the corrugations of the plate 2 cross and abut the corrugations of the plates 1 and 3. In Figures 2 and 3 only two plates are illustrated and Figure 2 shows how the plates 1 and 2 may be spot welded together as indicated at 4, whereas Figure 3 shows the plate 2 being provided with the pip or protuberance 5 corresponding with an aperture 6 in the plate 3 to provide for mechanical interlocking of the adjacent plates.In both cases, the strength requirement of the joining of adjacent plates is not very great since the strength of the series of plates is intended to be in a compression rather than shear mode.

Figure 4 shows the provision of grooves 7 across the bases of the corrugations of the plates so as to cooperate with the upper portions of the troughs of the adjacent plate to locate the plates relative to each other.

In Figure 5 the corrugations of the outer plates 1 and 3 illustrated are shown as being "90 out of phase", whereas in Figure 6 they are shown as being "in phase". In Figure 7 there is shown an intermediate relationship which the corrugations are staggered.

The series of plates form what may be termed a honeycomb structure and the spaces between the plates may be filled with viscous liquid, such as glues or resins or alternatively, the sealed spaces may be evacuated. This in particular would assist in any clamping arrangement between the plates.

Figure 8 shows a sandwich 10 of plates which form the head or follower of a plate heat exchanger frame. As such, it will, particularly if a head, have connecting ports in it for supply or discharge of feed or service fluid, and such ports may conveniently form a means for holding the honeycomb structure in position. As illustrated in Figure 8, a bush 11 of corrosion resistant material extends through aligned holes in the plates of the structure and is secured to inner and outer flanges 12 and 13 respectively. By having two or four such ports formed in the component, adequate shear strength may be provided.

It is also envisaged that in this application of the invention, which may also be applied to plate evaporators as well as plate heat exchangers, the outermost plates of the component 10 will be formed of corrosion resistant material such as stainless steel or titanium, or at least clad with such material, whereas the inner plates will be of much cheaper mild steel. In addition, it may be that the plates towards the outside of the structure will need to be of somewhat thicker gauge material because of'the greater point loadings which may be met in practice.

Figure 9 shows an attachment in the form of a cross bar 1 5 which may be used to absorb tie-bar loadings when the component is used as a head or follower of a heat exchange device. Such a cross bar 15 will significantly reduce the point loading on the structural component and may be welded to the outside plate.

Figures 10 and 11 illustrate an alternative to the use of a cross bar 15. In this case, the component 10 is provided with a further pair of aligned apertures 1 6 which receive protrusions 17 on an adapter 18 which has an aperture 19 to receive a tie-bar 21 which extends along the outside of the heat exchange pack which is illustrated at 22. For additional strength, the adapter 18 may be provided with an inclined faced 23 where it abuts the edge of the component 10.

Claims (14)

1. A laminar structural component comprising a series of profiled plates assembled and secured together with each plate abutting the adjacent plate or plates at a plurality of zones to form a coherent structure.

2. A head or follower, being a component for a plate heat exchanger or evaporator frame, comprising a series of profiled plates assembled and secured together with each plate abutting the adjacent plate or plates at a plurality of zones to form a coherent structure.

3. A component as claimed in claim 1 or 2, in which the plates are welded together.

4. A component as claimed in claim 1 or 2, in which the plates are mechanically interlocked with the adjacent plates.

5. A component as claimed in claim 1 or 2, in which the plates are clamped together.

6. A component as claimed in any of the preceding claims, wherein some or all of the spaces between the adjacent plates are filled with viscous liquid.

7. A component as claimed in any of claims 1 to 5, in which the spaces between the plates are sealed and evacuated.

8. A component as claimed in any of the preceding claims, in which the outermost plates of the series are of corrosion-resistant material and the inner plates are of less expensive material.

9. A plate heat exchanger or component including a head and/or follower as claimed in any of claims 2 to 8.

10. A plate heat exchanger as claimed in claim 9, in which tie bars for the heat exchanger pack are anchored to the head and follower by cross bars.

11. A plate heat exchanger as claimed in claim 9, in which tie bars for the heat exchanger pack are anchored to the head and follower by adaptors.

12. A structural component substantially as hereinbefore described with reference to the accompanying drawings.

13. A head or follower for a plate heat exchanger as hereinbefore described with reference to the accompanying drawings.

14. A plate heat exchanger substantially as hereinbefore described with reference to the accompanying drawings.