Heat exchanger element obtained by casting, and method for preparing polystyrene patterns for casting

Abstract

A heat exchanger element obtained by sand casting, having a modular structure and comprising a right head module, a left head module, and at least one optional intermediate module.

Description

The invention relates to a heat exchanger element obtained by sand casting and to a method for preparing polystyrene patterns for said casting.

BACKGROUND OF THE INVENTION

A casting process, particularly for casting aluminum alloy elements, is known which provides for the preparation of a polystyrene pattern which replicates exactly the shape of the casting and is embedded in sand; during the pouring of the molten metal, the metal replaces the polystyrene, which evaporates, and the desired element is thus obtained.

This casting process is known as “lost foam”.

The polystyrene pattern is obtained by connecting together by gluing component sectors, each of which is provided by means of an appropriately provided apparatus which, due to a certain inherent complexity, has a high cost.

It is also known that there are heat exchangers, used particularly in boilers for generating hot water, which are studied so that they are manufactured by composing identical elements in a number which is proportional to the thermal power to be obtained; a certain range of capacities to be marketed is thus provided, but such range is necessarily limited.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a heat exchanger element which can be obtained with the lost foam casting process and to also provide a method for preparing polystyrene patterns for performing such casting, which allow to provide, at a reduced cost, a very wide range of available thermal powers.

This aim is achieved by a heat exchanger element according to the invention, characterized in that it has a modular structure which comprises a right head module, a left head module, and at least one optional intermediate module.

A method for preparing polystyrene patterns for sand casting differentiated elements of heat exchangers of the type described above is characterized in that it comprises:

• • a first step for obtaining three sectors: a first sector for forming the right head module, a second sector for forming the left head module, and a third sector for forming an intermediate module;
  • a second step for assembling the complete pattern by connecting together by gluing the two sectors that form the right and left heads, with the optional interposition of a number of sectors for forming an intermediate module, selected as a function of the thermal power to be obtained from said exchanger element.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will become better apparent from the description of some embodiments thereof, illustrated by way of nonlimiting examples in the accompanying drawings, wherein:

FIG. 1 is a perspective view of an exchanger element according to the invention;

FIG. 2 is a front view of the exchanger element shown in FIG. 1;

FIG. 3 is a front view of the three polystyrene sectors for forming patterns according to the invention;

FIGS. 4, 5 and 6 are views of exchanger elements according to other embodiments according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the FIGS. 1 and 2, the reference numeral 1 generally designates a heat exchanger element which has a modular composition, since it is composed of a right head module 2, three identical intermediate modules 3, 4 and 5, and a left head module 6.

The polystyrene pattern for sand casting the element 1 is obtained by connecting together by gluing the two sectors 7 and 8 designed to form respectively the right head 2 and the left head 6 and at least one and preferably three sectors such as the one designated by the reference numeral 9, which are designed to form the three intermediate modules 3, 4 and 5.

By joining selectively different numbers of sectors such as the ones shown in FIG. 3, it is possible to obtain polystyrene patterns for casting a very wide range of differentiated exchanger elements: thus, FIG. 4 illustrates an exchanger element 10 which has a minimal thermal power, since it comprises only the two heads 11 and 12 obtained from polystyrene sectors 7 and 8.

FIG. 5 is a view of an element 13 which has a higher thermal power, since it comprises, in addition to the two heads 14, 15, also the intermediate module 16 obtained from a polystyrene sector 9.

FIG. 6 is a view of element 17, which has an even higher thermal power, but not as high as the element 1, since it comprises, in addition to the two heads 18 and 19, two intermediate modules 20 and 21.

It is therefore evident that it is possible to obtain a very wide range of exchanger elements having differentiated thermal power, and it is important to note that this possibility is achieved in terms of great economy because the factor that most affects the entire process, constituted by the cost of the apparatuses designed to provide the polystyrene patterns, is minimized: the number of these apparatuses is in fact reduced, regardless of the thermal power of the element to be obtained, to only the three fixtures designed to obtain the three sectors shown in FIG. 3.

The described invention is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements.

The disclosures in Italian Patent Application no. MN2006A000076, from which this application claims priority, are incorporated herein by reference.

Claims

1. A heat exchanger element obtained by sand casting, comprising a modular structure which comprises a right head module, a left head module, and at least one intermediate module.

2. A method for preparing polystyrene patterns for sand casting differentiated elements of exchangers according to claim 1, comprising:

a first step for obtaining three sectors: a first sector for forming the right head module, a second sector for forming the left head module, and a third sector for forming the intermediate module;

a second step for assembling the complete pattern by connecting together by gluing the two sectors that form the right and left heads, with interposition of a number of sectors for forming the intermediate module, selected as a function of the thermal power to be obtained from said exchanger element.