HU192238B - Heat exchanger - Google Patents

Abstract

The present invention relates to a heat exchanger for cooling or heating liquids, particularly for cooling liquid liquids such as milk. The heat exchanger has straight heat exchanger members (10) which are connected to the cooling circuit by soluble connections on the liquid side to be cooled. The inner tube (1) of the heat exchanger member (10) for conveying the fluid to be cooled generally is surrounded by rolling with a damped intermediate tube (3), and is surrounded by a distance, preferably cylindrical tubular outer casing (6). In general, the space (8) between the last two tubes (3, 6) is provided by the refrigerant, e.g. to receive freon. There is a display path between the inner tube (1) and the intermediate tube (3), which is formed by a groove (2) recessed from the outside of the inner tube (1) and sealed with the cylindrical inner surface of the intermediate tube (3). Its size is selected - its resistance is so low that, on the one hand, in case of a possible failure, it can either cool the liquid to be cooled or the refrigerant, or to wash the spiral display sand with a chemical fluid for control or purge with gas. -1-

Description

The present invention relates to a heat exchanger having a double-walled inner tube, a display passage between these tubes, and an outer jacket surrounding the inner tube.

Cooling technology for food liquids is subject to stringent regulations worldwide. Cooling of such liquids is generally not allowed in direct evaporation heat exchangers, since in the event of a break in the heat exchanger, the refrigerant (eg freon) may enter and infect the liquid to be cooled (eg milk). For this reason, medium-range refrigeration systems are used for the cooling of food liquids, which, while safe, have high investment, installation and operational costs and are relatively low in efficiency due to inevitable thermal and mechanical losses of the system. Recently, three-walled "tube-to-tube" heat exchangers have been used to utilize the condensing heat of refrigerators in which a casing tube is wound along a spiral curve to the innermost tube. Thus, the walls of both tubes are embossed along said spiral curve and these embossed wall portions are sometimes pressed against one another and sometimes not. This creates a groove between the innermost tube and the casing tube, which projects into the open air. Usually, the liquid to be cooled flows into the innermost tube, e.g. hot water, and in the space between the casing and the outermost tube, refrigerant, usually from a technological process, e.g. Freon. In the event of a hole in the pipe defining the water space or the refrigerant space, the escaped fluid is discharged through said groove and indicates a malfunction, so that, if the cooling system is properly controlled, contamination of the two circuits can be prevented.

By their design, the heat exchangers of the type described above are primarily suitable for protection of the refrigerant circuit, since the spiral groove made by rolling is usually of very high resistance, and therefore it is primarily gaseous refrigerant, e.g. freon can leak and thus report a bug. Even if water leaks through the groove, there is a very high probability that the groove will become blocked in the case of a fluid that is denser than water in the event of a hole in the fluid transfer tube; Thus, there is no fault indication, and there is a danger that the technological fluid entering the groove will clog, start to decompose and infect the technology product as the error remains hidden.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat exchanger with a direct evaporation system which eliminates the risk of mixing the refrigerant with the refrigerated product with high safety and thus can be used in the food industry to cool liquid foods such as milk.

The invention is based on the discovery that when a heat exchanger of the triple wall "tube" type of the type described above is formed with a display groove, the danger of clogging even with relatively dense liquids (e.g. milk) is eliminated with great certainty, In the case of - not only the refrigerant, if not necessarily the case with the process liquid, liquids, e.g. for cooling food for which the highest hygiene standards are set.

The invention is further based on the discovery that when the heat exchanger tube or tubes are straight or substantially straight and are installed in the cooling system with easy and quick-release connections, they are subject to regular visual inspection and / or mechanical cleaning to meet the highest hygiene requirements. , so it can be used for food refrigeration and similar care-intensive tasks.

Based on this discovery, the object of the present invention has been solved by the use of a heat exchanger having one or more heat exchanger members consisting of an inner tube surrounded by an intermediate tube, an outer jacket spaced, preferably concentrically, between the intermediate tube and the inner tube. and is located in the display passage between the intermediate pipe and the heat exchanger,

- have a linear or near-linear heat exchanger member (s);

the heat exchanger member (s) is / are coupled to the cooling system by releasable connections;

the display passage is formed by a spiral-shaped groove extending from the outside to the inner tube wall, which is sealed with the cylindrical inner surface of the intermediate tube, which fits snugly against the inner tube and extends in the same direction as the longitudinal center axis of the inner tube. It is expedient to have one or more connecting grooves, which also function as a display groove, which are externally recessed in the masonry wall and intersect the threads of the helical display groove and which are also sealed with the cylindrical surface of the intermediate tube.

Straight or substantially straight heat exchanger members are to be understood as meaning heat exchanger members whose inner tube is transparent, can be seen through it, and its condition can be visually verified. The releasable connection of the heat exchanger members must provide for easy and fast removal and installation of the heat exchanger members in any number and frequency of choice, e.g. at the end of each shift in a food processing plant, the food contact internal surfaces of the heat exchanger members may be visually inspected and mechanically cleaned.

Preferably, the intermediate tube is rolled onto the inner tube.

According to another feature of the invention, the groove or grooves that make up the display passageway, for example for visual inspection, preferably extend into or out of a location (s) in the region of one or both ends of the heat exchanger. The display passage or passages generally extend into or out of one or more display spaces to which a pipe or nozzle is connected.

192 238

In most cases, the inner tube is the fluid to be cooled, and the space between the intermediate tube and the outer jacket, preferably cylindrical, is provided for the transfer of refrigerant.

In another aspect of the invention, the inner tube is made of stainless steel and the intermediate tube and outer tube are of copper.

A further preferred embodiment of the heat exchanger is characterized in that the helical groove and / or the connecting groove or grooves are of cross-sectional dimension which allows the display passage to be flushed and / or blown with gaseous medium.

In another exemplary embodiment, the inner tubes of the heat exchanger members are joined and passed through end plates; and lids having removable connections attached to these end plates to form the inlet and outlet chambers and the turn chambers with the end plates and the inner tubes extending into these chambers. In this case, it is expedient to have a pipe end for supplying and discharging the liquid to be cooled to one of the (front) end plates - preferably these pipe nozzles are formed in one member with the lid and at the end of the pipe nozzles . It is further preferred that the heat exchanger members are arranged in a lying cylinder-shaped chamber parallel to the components of the chamber.

The invention will now be described in more detail with reference to the accompanying drawings, which show a preferred embodiment thereof and some structural details thereof. 1 is a schematic longitudinal sectional view of a heat exchanger according to the invention;

Figure 2 shows a detail of a heat exchanger member in a larger longitudinal sectional view;

Figure 3 is another side view, partly in longitudinal section, of another embodiment of an inner tube of a heat exchanger member;

Figure 4 is a sectional view taken along line A-A in Figure 3;

Figure 5 is a perspective view of the outer peripheral surface of the inner tube.

The heat exchanger of the present invention, shown in Figure 1, has straight heat exchanger members 10 extending parallel to each other in a longitudinal direction inside a stationary cylindrical chamber 11. The inner tubes 1 of the heat exchanger members 10 surrounded by intermediate tubes 3 for transferring the liquid to be cooled, and the space inside the sheaths 6 surrounding the intermediate tubes is provided by the refrigerant, e.g. is intended to accommodate freon. (The design of the heat exchanger members 10 will be described in detail in Figures 2-5.)

As shown in FIG. 1, the ends of the inner tubes 1, which are not surrounded by the intermediate tubes 3, are secured to each end plate 12a, 12b so that they pass through them.

The front cover 12 is connected to the end face 12a by easily and rapidly releasable connections along its edges to form an inlet chamber 14, a turning chamber 15 and an outlet chamber 16 for the liquid to be cooled from the direction of arrow a '. A nozzle 17 serves to supply the liquid to be cooled to the inlet chamber 14, and a nozzle 18 flows out of the outlet chamber 16;

^{5 shows} the flow direction of the outlet coolant as shown in FIG. 1A.

The end plate 12b can be easily and quickly soluble links along the edges of a cover 19 is attached to the lid 12b, 20a, 20b form a Ford ¹⁰ tókamrákat.

The refrigerant enters the heat exchanger through the conduit 22 in the direction of arrow b and exits the conduit 23 in the direction indicated by the arrow b 'through the spaces inside the jacket 6. Said sheaths are connected to a common space by the connecting channels ¹⁵ .

At the ends of the pipe fittings 17, 18 are quick coupling elements (not shown), e.g. cordless fasteners, bolts, or high-threaded bolts are used to quickly and easily connect the respective piping ²⁰ to the ends of the cooling system, and to remove the piping from the pipe nozzles 17, 18 as well. The lids 13 and 19 provide the same quick and easy removal of the lids 25 between the lids and the end faces 12a, 12b. Thus, e.g. in a milk cooling plant, the lids 13, 19 can be removed after each shift, viewed through the inner tubes 1, illuminated and mechanically washed.

Figure 2 shows a larger scale of a portion of the heat exchanger member 10 used in the heat exchanger of Figure 1. The structural elements already described are denoted by the reference numerals already used.

Preferably, the helical groove or the connecting groove or grooves are rolled into the inner tube wall.

The jacket tube and the outer jacket may be secured to each other by brazing, thereby closing the space between the tubes e '.

The inner tube 1, for example made of stainless steel, is provided for conveying the liquid to be cooled and has a groove 2 formed in the masonry into a spiral-shaped display passage; the size (depth and width) of the ho45 rony is so large that even if it is relatively dense (e.g., milk), the fluid flowing through the inner tube 1 can be discharged with complete safety. The inner tube 1 can be externally mounted e.g. in the copper 3 rocks 50, the tube is tightly rolled - cylindrically sealed - but its inner cylindrical surface does not follow the line of the groove 2 but closes (delimits) it from the outside, so the display groove thus remains constant throughout, it does not come into contact with the pipe anywhere and consequently there are no clogging sites or areas. foci in the display passage. The groove 2 extends into a spray area display area 4 of the intermediate pipe 3, to which a port 5 is connected.

The copper tube 3, which is drawn on the inner tube 1 with a helical groove 2, is surrounded by a tubular outer casing 6, which is also made of copper _{g5 at} a distance y from it. Thermal expansion of stainless steel and copper

192 238 factors are virtually identical. The latter is connected at its ends to the intermediate tube 3 by brazing 7. The annular space 8 between the outer jacket 6 and the intermediate tube 3 serves to evaporate the refrigerant, e.g. freon. The tube 9 serves to guide the freon into space 8. The longitudinal geometric center axis of the heat exchanger is denoted by the reference letter x.

The liquid to be cooled flows in the inner tube 1 in accordance with the arrow; refrigerant, e.g. freon enters and flows through space 8 in the direction indicated by arrows b; and arrow c illustrates how the refrigerant and / or liquid to be cooled appears at the end of the pipe fitting 5 if the inner pipe 1 and / or the intermediate pipe 3 are punctured. Indeed, through the hole (s) formed, the refrigerant and / or the liquid to be cooled enters the helical display groove 2 and flows unhindered therethrough into the display space 4, from where it exits to indicate a fault. The coupling 5 also allows, e.g. supply chemical flush to the display passage and / or purge the vent passage with a gaseous medium.

In the heat exchanger member 10 described above, the liquid to be cooled flows through the inner tube 1 in the direction of arrow a, while in the counterflow 8 it flows in accordance with arrows b. The metallic connection between the stainless steel inner tube 1 and the copper intermediate tube provides good heat transfer, while the grooved surface of the inner tube 1 increases the heat transfer coefficient between the liquid to be cooled and the display groove 2 with proper flow cross section excludes There is a risk of mixing refrigerant with the liquid to be cooled, because if the fault is detected, the cooling system can be stopped immediately. In Figure 1, a display location is designated by reference numeral 30.

3-5. Figures 1 to 5, which show only the inner tube 1 for better clarity, illustrate how the function of the display groove can be further improved or improved. The helical groove 2 is recessed into the outer surface of the tube 1 as in the embodiment of Fig. 2, but here the threads of the circumferential helical groove are intersected by two connecting grooves 25 extending in opposite directions on the outer peripheral surface. Thus, in the event of a failure, the fluid or refrigerant to be coiled into the coil groove 2 may not have to pass through this coil groove to enter the display area 4 shown in FIG. This way, any error can be detected in a very short time.

An advantage of the invention is that it allows direct cooling of food grade liquids in a direct evaporation system, which cools the liquid to the desired temperature for a minimum of a few seconds, with the additional advantage that liquid foods, e.g. In the case of milk, it stops the growth of bacteria and allows the immediate further processing of the chilled product or the immediate removal of the chilled product. The heat exchanger space requirement is small, and its investment and operating costs are significantly lower than those currently known for similar systems. The display groove eliminates the risk of contamination of the liquid to be cooled; in addition, the display groove can be washed. The scope of application of the heat exchanger is very wide. in the food industry (eg refrigeration of milk, wine, fruit concentrates, fruit juices, egg juices); in the pharmaceutical and chemical industry (process cooling); but also for heat pump operation in water supply networks.

The invention is, of course, not limited to the example detailed above. but can be accomplished in many ways within the scope of the claims.

Claims (14)

Claims CLAIMS 1. For cooling or heating a heat exchange fluid, in particular for liquid food such as milk, the heat exchanger comprises one or more heat exchanger members comprising an inner tube surrounded by an intermediate tube, preferably intermediate concentrically between the outer tube and the inner casing. It consists of a display passage between the tube and the intermediate tube, characterized in that: - has a linear or near-linear heat exchanger member (s) (10); - the heat exchanger member (s) (10) are disposed with releasable connections in the coolant circuit of the cooling system; - a spiral in the same direction as the geometric longitudinal axis (x) of the inner tube (1) extending from the outside of the display passage into the masonry of the inner tube (1), sealed against the cylindrical inner surface of the intermediate tube (3) the groove (2). (Figure 2). Heat exchanger according to Claim 1, characterized in that one or more component grooves, which are also sealed with the cylindrical surface of the intermediate tube (3), are also recessed from the outside in the wall of the inner tube (1) and cut through the threads of the helical display groove (2). a functioning connecting sleeve (25). (Figures 3-5). Heat exchanger according to Claim 2, characterized in that the inner tube (1) has two mutually opposing, convex grooves (25). (Figures 3-5). 4. Heat exchanger according to any one of claims 1 to 3, characterized in that the intermediate tube (3) is rolled onto the inner tube (1). 5. A heat exchanger according to any one of claims 1 to 4, characterized in that it extends into a location (s), preferably in the region of one or both ends of the heat exchanger, enabling the spiral groove (2) or / and / or one or more connecting grooves (25) forming the display passage. Who. (Figure 2) 6. The heat exchanger of claim 5, wherein the one or more display passages is one or more 192 238 extends into a plurality of display spaces (4) to which a pipe or nozzle (5) is connected. (Figure 2) 7. Heat exchanger according to one of Claims 1 to 3, characterized in that the inner tube (1) is provided for transferring the refrigerant, the space (8) between the intermediate tube (3) and the outer jacket (6), preferably cylindrical. (Figure 2) 8. Heat exchanger according to any one of claims 1 to 4, characterized in that the inner tube (1) is made of stainless steel, the intermediate tube (3) and the outer tube (6) are made of copper. 9. Heat exchanger according to any one of claims 1 to 4, characterized in that the helical groove (2) and / or one or more connecting grooves (25) are of cross-sectional dimensions which allow washing of the display passages and / or blowing with gaseous medium. 10. Heat exchanger according to any one of claims 1 to 4, characterized in that the helical groove (2) and / or one or more connecting grooves (25) are recessed into the wall of the inner tube (1). 11. Heat exchanger according to any one of claims 1 to 4, characterized in that the jacket tube (3) and the outer jacket (6) are secured to each other by brazing (7), thereby closing the space (8) between these tubes (3, 6). 12. A heat exchanger according to any one of claims 1 to 4, characterized in that the inner tubes (1) of the heat exchanger members ( ⁵ ) are joined to and passed through end plates (12a, 12b); and lids (13; 19) connected to said end panels (12a, 12b) by means of releasable connections which form an inlet and outlet chamber ^{1 (3} (14, 16) and a pivoting chamber (15; 20a, 20b) with the end panels (12a, 12b). , and the inner tubes (1) extend into these chambers (14-16; 20a, 20b) (Fig. 1). A heat exchanger according to claim 12, characterized in that tubular nozzles (17, 18) for supplying and discharging the liquid to be cooled are connected to one of the (front) end plates ¹⁵ (13), preferably the tubular nozzles are formed in one member. at the ends of the pipe fittings (17, 18) there are means for establishing a soluble connection ²⁰ with the pipes of the cooling system. (Figure 1) Heat exchanger according to Claim 12 or 13, characterized in that the heat exchanger members (10) are located in a lying cylinder chamber (10), in which the chamber (11) is located. Arranged parallel to 25 of its creators.