Self-pumping heat exchange unit

Description

Object of the Invention

[0001] The present invention belongs to the field of heat exchange apparatuses, and more specifically to machines for heat exchange between fluids having the same or different characteristics, applicable in different sectors, such as the food sector, pharmaceutical sector, health sector, etc.

[0002] The main object of the present invention is a heat exchange unit which fundamentally stands out because it provides a self-pumping effect and keeps the exchange surface clean at all times, improving the heat transfer coefficient and allowing a substantial reduction in head losses through its inner and outer tubes, said head losses being generated by friction of the actual inner walls of the tubes.

Background of the Invention

[0003] Machines for heat exchange between fluids which generally have at least one inner tube through which the "product fluid", i.e., fluid to be heated or cooled, circulates and an outer tube or shell, through which the "service fluid", i.e., heat transfer fluid, circulates are known today.

[0004] More specifically, heat exchangers the inner conduits of which are provided with cleaning means, thus providing a self-cleaning effect on their inner surface and allowing maintenance and a prolonged service life of said heat exchangers, reducing the dead time thereof, are known in the current state of the art. An example of the aforementioned exchangers can be found in Spanish patent application ES2158752. On the other hand, the international patent Application WO2013/007842 A1 describes a heat-exchanging device, that can be used for the heat treatment of products such as juices, pulp and other food, liquid or particulate products. Nevertheless, current machines for heat exchange between fluids have several problems and drawbacks among which the following stand out:

• They have a high head loss, which causes a considerable and significant decrease in machine performance.
• The inner walls of their tubes experience very high pumping pressures with the risks and problems it entails, particularly in cases of high viscosity fluids or fluids with a concentration of solids.
• They do not allow regulating or modifying the pumping flow rate of the product fluid since it is predetermined by the pump before the machines are connected thereto.
• Their shells are single-pass shells, so they have a low heat transfer coefficient, in addition to involving a greater demand for pumping the service fluid to the pump, increasing costs.
• The inner walls of the inner tubes are not completely cleaned, the cleaning means not acting on parts or sections of said tubes.
• They must be connected to a pump which moves and pumps the fluids circulating through the inside of the tubes.
• The mechanisms for opening current exchange machines when performing inspection and maintenance tasks are complex, slow and tedious mechanisms.
• They are only operative for a specific type of low viscosity or high viscosity fluids, but without the possibility of working with both fluids.

Description of the Invention

[0005] The present invention alleviates the aforementioned drawbacks by providing a self-pumping heat exchange unit which successfully reduces head loss through its conduits, substantially optimizing the heat transfer coefficient, and also allowing regulating and obtaining different pumping flow rates for the product fluid, i.e., fluid to be heated or cooled.

[0006] More particularly, the heat exchange unit object of the invention is of the type comprising an outer shell provided with an inlet and an outlet for a "service" fluid, i.e., a heat carrier fluid, being able to be glycol or cold water vapor, thermal oil, etc.; at least one hollow inner tube housed inside the outer shell and also linked to an inlet and an outlet for a product fluid, i.e., fluid to be heated or cooled; an elongated rotary rod arranged inside the at least one inner tube and having cleaning means for cleaning the inner wall of the at least one inner tube. In this context, "head losses" must be understood as losses generated by friction of the actual inner walls of the tubes.

[0007] Therefore, the heat exchange unit described herein stands out fundamentally because it additionally comprises: scraping elements linked to the rotary rod and suitable for scraping and detaching the product fluid accumulated or fixed on the inner wall of the at least one inner tube; and an endless spiral also linked to the rotary rod, dimensionally suitable for running along and surrounding the rod longitudinally through the spaces existing between the scraping elements, said endless spiral being suitable for displacement of the product fluid circulating through the at least one inner tube, generating a self-pumping effect.

[0008] The scraping elements preferably have an elongated planar configuration, thus allowing covering the entire the inner surface of the inner tubes, increasing cleaning efficiency.

[0009] According to the invention the heat exchange unit comprises three inner tubes. So by means of varying the rotational speed of the rods existing in the inner tubes, and therefore of the endless spiral, it is possible to achieve different pumping flow rates for the product fluid circulating through said inner tubes, which allows improving the heat transfer coefficient and reducing the head losses generated by friction of the actual inner walls of the tubes.

[0010] On the other hand, in relation to the drive of the rotational movement of each of the rotary rods, the arrangement of a geared motor connected through a central shaft with a main gear to which secondary gears connected with the ends of each of the rotary rods are linked, has been envisaged. Integral movement and synchronized rotation of the rods are thus achieved. The aforementioned main gear is also preferably made of stainless steel, whereas the secondary gears are manufactured from a plastic material, thus preventing the irritating noises produced by the transmissions of the gears, while at the same time said secondary gears are a fuse element as a means for protecting against surge currents.

[0011] Finally, it must be pointed out that the heat exchange unit herein described has been envisaged to be applicable in the food sector, health sector, environmental sector or industrial sector. It can be also used as a regenerative unit, i.e., using one and the same product fluid in both parts of the unit, namely, the shell and the inner tubes, thus recovering the actual energy of the product fluid.

[0012] Therefore, the present invention provides a heat exchange unit according to claim 1 which, in addition to efficiently removing residues from the inner wall of the tubes, reducing head loss and substantially improving the heat transfer coefficient, also stands out for obtaining a "self-pumping effect" of the product fluid circulating through said inner tubes, which makes it possible for the requirements of the outer pump to be lower, even to the extent of being able to dispense with said outer pump in some cases, being a more efficient, economical and viable alternative solution than the self-cleaning systems of current heat exchangers.

Description of the Drawings

[0013] To complement the description that is being made and for the purpose of aiding to better understand the features of the invention according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description in which the following has been depicted with an illustrative and nonlimiting character:

Figure 1 shows a general perspective view of the self-pumping heat exchange unit object of the invention.

Figure 2 shows a perspective view of the shell of the exchange unit of the invention, with its inlets and outlets for the service fluid, three inner tubes being seen according to this embodiment.

Figure 3 shows a perspective view of one of the rods arranged internally inside each of the three inner tubes of Figure 2.

Figure 4 shows a detailed view of the gears for driving each of the rods existing inside the inner tubes.

Preferred Embodiment of the Invention

[0014] A preferred embodiment is described below with reference to the aforementioned drawings, without this limiting or reducing the scope of protection of the present invention.

[0015] Figure 1 shows a general view of the self-pumping heat exchange unit (1) which comprises:

• an outer shell (10), shown in greater detail in Figure 2, provided with an inlet (11) and an outlet (12) intended for the circulation of a "service" fluid, i.e., a heat carrier fluid;
• three hollow inner tubes (20) housed inside the outer shell (10) and also linked to an inlet (21) and an outlet (22) for a product fluid, i.e., fluid to be heated or cooled;
• an elongated rotary rod (30), shown in Figure 3, arranged inside at least one inner tube (20),
• scraping elements (40) having an elongated planar configuration, also depicted in Figure 3, linked to the rotary rod (30) and suitable for scraping and detaching the product fluid accumulated or fixed on the inner wall of the at least one inner tube (20), and
• an endless spiral (50) also linked to the rotary rod (30), dimensionally suitable for running along and surrounding the rotary rod (30) longitudinally through the spaces existing between the scraping elements (40), as seen in said Figure 3, said endless spiral (50) being suitable for displacement of the product fluid circulating through the at least one inner tube (20), generating a self-pumping effect.

[0016] Furthermore, as can be seen in Figure 1, the heat exchange unit (1) additionally comprises a main geared motor (60) connected through a central shaft (70), shown in Figure 4, with a main gear (71) made of stainless steel, the latter is in turn connected with secondary gears (72) which are linked to the ends of each of the rotary rods (30), as shown in Figure 3. Said secondary gears (72), depicted in Figures 3 and 4, are manufactured from a plastic material, such that in addition to acting as a safety fuse element, it allows preventing the irritating noise generally produced by the transmissions of the gears.

[0017] Said Figure 1 also shows an auxiliary geared motor (80) which is coupled to the main geared motor (60) and which allows separating the heat exchange unit into two blocks when connected with a threaded screw and a nut for a quick, simple and comfortable opening of the heat exchange unit (1), facilitating inspection and/or maintenance tasks by qualified personnel. Finally, it must be pointed out that the unit incorporates a lower frame (90), also shown in Figure 1, making up the base support of the heat exchange unit (1), and which in the present embodiment further comprises an additional telescopic prolongation (91) provided with wheels (92) in the lower portion, thus facilitating its movement and allowing it to take up minimum space.

[0018] Finally, the improvements and advantages obtained by means of the heat exchange unit of the present invention must be mentioned:

• A total performance increase as a result of a substantial reduction in head loss through its conduits.
• Problems derived from high pumping pressures are eliminated due to its self-pumping effect.
• Possibility of regulating the pumping flow rate of the product fluid according to the needs of each application.
• "Multipass" possibility of the endless spiral, thus improving the heat transfer coefficient, so the requirements of the pump are lower.
• Maximizing cleaning of the inner walls of the inner tubes.
• It allows dispensing with or significantly reducing the needs of a preceding pump since the self-pumping effect is sufficient.
• It allows quick, comfortable and simple opening/closing of the exchange unit for inspection and/or maintenance tasks.
• It allows working and operating with different types of low or high viscosity fluids.

Claims

1. Self-pumping heat exchange unit (1) comprising an outer shell (10) provided with an inlet (11) and an outlet (12) for a heat carrier fluid; three inner tubes (20) housed inside the outer shell (10) and also linked to an inlet (21) and an outlet (22) for a product fluid, that is a fluid to be heated or cooled; an elongated rotary rod (30) arranged inside each inner tube (20) and having cleaning means for cleaning the inner wall of each inner tube (20), the cleaning means comprising:

- scraping elements (40) linked to the rotary rod (30) and suitable for scraping and detaching the product fluid accumulated or fixed on the inner wall of the inner tube (20),

- an endless spiral (50) also linked to the rotary rod (30),

- a main geared motor (60) connected through a central shaft (70) with a main gear (71), in turn connected with the end of each rotary rod (30),

wherein the endless spiral (50) is dimensionally suitable for running along and surrounding the rotary rod (30) longitudinally through the spaces existing between the scraping elements (40), said endless spiral (50) being suitable for displacement of the product fluid circulating through the respective inner tube (20), generating a self-pumping effect,
characterized in that the self-pumping heat exchange unit (1) further comprises:

- an auxiliary geared motor (80) which is coupled to the main geared motor (60), and connected with a threaded screw and a nut for allowing separation of the heat exchange unit into two blocks;

- a lower frame (90) making up the base support of the heat exchange unit (1), said lower frame (90) comprising an additional telescopic prolongation (91) provided with wheels (92) in the lower portion;

and wherein the main gear (71) is linked to secondary gears (72) connected with the ends of each of the rotary rods (30), said secondary gears (72) being made of a plastic material.

2. Self-pumping heat exchange unit (1) according to claim 1, characterized in that the scraping elements (40) have an elongated planar configuration.

3. Self-pumping heat exchange unit (1) according to claim 1, characterized in that the main gear (71) is made of stainless steel.

Ansprüche

1. Selbstpumpende Wärmetauschereinheit (1) mit einer Außenschale (10), die mit einem Einlass (11) und einem Auslass (12) für ein Wärmeträgerfluid versehen ist; drei Innenrohren (20), die in der Außenschale (10) untergebracht sind und auch mit einem Einlass (21) und einem Auslass (22) für ein Produktfluid gekoppelt sind, das ein zu erhitzendes oder zu kühlendes Fluid ist; einer länglichen Rotationsstange (30), die innerhalb jedes Innenrohres (20) angeordnet ist und einem Reinigungsmittel zum Reinigen der Innenwand jedes Innenrohres (20); wobei das Reinigungsmittel umfasst:

- Abschabelemente (40), die mit der Rotationsstange (30) gekoppelt und zum Abschaben und Ablösen des Produktfluides geeignet sind, das sich an der Innenwand des Innenrohres (20) angesammelt oder angesetzt hat,

- eine Endlosspirale (50), die ebenfalls mit der Rotationsstange (30) gekoppelt ist,

- einen Hauptgetriebemotor (60), der durch eine Zentralwelle (70) mit einem Hauptzahnrad (71) verbunden ist, das seinerseits mit dem Ende jeder Rotationsstange (30) verbunden ist,

wobei die Endlosspirale (50) von der Abmessung her zum Laufen entlang und um die Rotationsstange (30) herum längs durch die zwischen den Abschabelementen (40) vorhandenen Räume geeignet ist, wobei die Endlosspirale (50) zum Verdrängen des Produktfluides geeignet ist, das durch das jeweilige Innenrohr (20) zirkuliert, wodurch ein selbstpumpender Effekt erzeugt wird,
dadurch gekennzeichnet, dass
die selbstpumpende Wärmetauschereinheit (1) ferner umfasst:

- einen Zusatzgetriebemotor (80), der mit dem Hauptgetriebemotor (60) gekoppelt und mit einer Gewindeschraube und mit einer Mutter verbunden ist, um eine Trennung der Wärmetauschereinheit in zwei Blöcke zu ermöglichen;

- einen unteren Rahmen (90), der den Basisträger der Wärmetauschereinheit (1) bildet, wobei der untere Rahmen (90) eine zusätzliche teleskopische Verlängerung (91) umfasst, die mit Rädern (92) in dem unteren Abschnitt versehen ist;

und wobei das Hauptzahnrad (71) mit Sekundärzahnrädern (72) gekoppelt ist, die mit den Enden von jeder der Rotationsstangen (30) verbunden sind, wobei die Sekundärzahnräder (72) aus einem Kunststoffmaterial bestehen.

2. Selbstpumpende Wärmetauschereinheit (1) nach Anspruch 1, dadurch gekennzeichnet, dass die Abschabelemente (40) eine verlängerte planare Konfiguration aufweisen.

3. Selbstpumpende Wärmetauschereinheit (1) nach Anspruch 1, dadurch gekennzeichnet, dass das Hauptzahnrad (71) aus rostfreiem Stahl besteht.

Revendications

1. Unité d'échange de chaleur à pompage automatique (1) comprenant une coque externe (10) prévue avec une entrée (11) et une sortie (12) pour un fluide caloporteur ; trois tubes internes (20) logés à l'intérieur de la coque externe (10) et également liés à une entrée (21) et à une sortie (22) pour un fluide de produit, qui est un fluide à chauffer ou refroidir ; une tige rotative allongée (30) agencée à l'intérieur de chaque tube interne (20) et ayant des moyens de nettoyage pour nettoyer la paroi interne de chaque tube interne (20), les moyens de nettoyage comprenant :

des moyens de raclage (40) reliés à la tige rotative (30) et appropriés pour racler et détacher le fluide de produit accumulé ou fixé sur la paroi interne du tube interne (20),

une spirale sans fin (50) également reliée à la tige rotative (30),

un moteur à engrenage principal (60) raccordé par un arbre central (70) avec un engrenage principal (71) raccordé à son tour à l'extrémité de chaque tige rotative (30),

dans laquelle la spirale sans fin (50) est appropriée, du point de vue dimensionnel, pour s'étendre le long de et entourer la tige rotative (30) longitudinalement à travers les espaces existants entre les éléments de raclage (40), ladite spirale sans fin (50) étant appropriée pour le déplacement du fluide de produit circulant à travers le tube interne (20) respectif générant un effet de pompage automatique,

caractérisée en ce que l'unité d'échangeur de chaleur à pompage automatique (1) comprend en outre :

un moteur à engrenage auxiliaire (80) qui est couplé au moteur à engrenage principal (60) et raccordé à une vis filetée et un écrou pour permettre la séparation de l'unité d'échangeur de chaleur en deux blocs ;

un bâti inférieur (90) composant le support de base de l'unité d'échange de chaleur (1), ledit bâti inférieur (90) comprenant un prolongement télescopique supplémentaire (91) prévu avec des roues (92) dans la partie inférieure ;

et dans lequel l'engrenage principal (71) est relié aux engrenages secondaires (72) raccordés avec les extrémités de chacune des tiges rotatives (30), lesdits engrenages secondaires (72) étant composés d'une matière plastique.

2. Unité d'échangeur de chaleur à pompage automatique (1) selon la revendication 1, caractérisée en ce que les éléments de raclage (40) ont une configuration planaire allongée.

3. Unité d'échangeur de chaleur à pompage automatique (1) selon la revendication 1, caractérisée en ce que l'engrenage principal (71) est réalisé à partir d'acier inoxydable.

Drawing