DE2947757A1 - CORRODABLE CONTAINER FOR THE AUTOMATIC ADDITION OF A CORROSION INHIBITOR TO A COOLING SYSTEM - Google Patents

Description

29A7757

Corrodible container for the automatic addition of a corrosion inhibitor to a cooling system

The invention relates to a corrodible container for Storage of a corrosion inhibitor, which is suitably in a cooling system of a motor vehicle or in a other environment is to be arranged, wherein the container has at least one portion which consists essentially of is made of the same material as the heat exchanger in a cooling system, so it can corrode if that The coolant is partially or completely replaced by a corrosive liquid such as water For example, since a radiator made of aluminum tends to clog very quickly in the presence of corrosive water corrode, at least a part of the container for the corrosion inhibitor consists of an aluminum foil or of Aluminum sheet with a thinner section so that the foil or the thinner section can corrode through to the Release corrosion inhibitor in the coolant and thus prevent corrosion of the heat exchanger and the cooling system on a Bring minimum mum.

Contains coolant for the cooling system of motor vehicles usually ethylene glycol plus a small percentage of diethylene glycol. This liquid is diluted with water, to a glycol concentration of 50% or lower

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depending on the desired freezing point for the cooling system. Most companies that manufacture and / or sell ethylene glycol for cooling systems add corrosion inhibitors to the solution to prevent corrosion of the coolers, which are usually made of copper-brass *

These inhibitors are normally a mixture of one or more inorganic salts, such as phosphates, borates, nitrates, nitrites, silicates or arsenates, and an organic compound, such as benzotriazole, tolyltriazole or mercaptobenzothiazole, in order to prevent corrosion of the copper in this way. The solution is usually buffered to a pH of θ to 10 to reduce iron corrosion and neutralize glycolic acid, which is produced when ethylene glycol is oxidized. Most companies recommend that their antifreeze should be serviced a maximum of one or two years apart, however it has been found that the average automobile owner does not follow these instructions for maintaining -2Q ° F protection of the cooling system and does not check the coolant. whether this is rusty or dirty. Many motor vehicle owners only add water when the antifreeze has been lost through leaks or hose ruptures. This is more common in the more southern parts of the country than in the more northerly areas .

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In the case of normally serviced passenger cars, the cooling system must be monitored in 25% of automobiles after only one year 5 after two years this percentage increases to 50%. In normal radiators in copper-brass, especially in systems of aluminum, it is extremely important that the antifreeze or coolant mixture contains up to 55 i »to ethylene glycol 50th A decrease to 33% ethylene glycol and 67% / t water causes a considerable increase in metal corrosion. This is particularly important for cooling systems for higher temperatures, which are becoming more and more important with increasing emissions controls.

Furthermore, since gasoline consumption plays an increasingly important role, gains in size and weight reduction by replacing iron and steel with lightweight metals or Plastics are becoming increasingly important. As a result, more and more aluminum coolers are being used in cooling systems for automobiles instead of the copper-brass coolers previously used. As mentioned above, an aluminum radiator is the corrosive effect of a coolant or antifreeze that has a low percentage of ethylene glycol and / or in which there is an insufficient amount of the corrosion inhibitor in the coolant, more exposed. At a an additional amount of corrosion inhibitor must be added to such a system or the aluminum will begin to corrode, where it is eaten away relatively quickly. the

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The present invention solves this corrosion problem by it enables the automatic addition of a corrosion inhibitor to a coolant under corrosive conditions.

The present invention relates to an apparatus for automatic addition of a corrosion inhibitor when the corrosive effect of the engine coolant in a motor vehicle reaches or exceeds a predetermined value, the device being a closed container for the solid or liquid corrosion inhibitor, at least a portion of which is substantially the same Material is formed like the heat exchanger or cooler, through which the coolant flows and which it by corrosion attacks. This container part should not corrode in a properly measured ethylene glycol-water solution, but if the coolant becomes corrosive, the corrodible part should of the container will corrode at a faster rate or at the same rate as the material of the cooler. Since the corrodible material is much thinner than the material of the cooler, it is eaten through very quickly, so that the corrosion inhibitor can be released into the cooling system.

The present invention also relates to a device for releasing a corrosion inhibitor into a Cooling system in which a sheet of the material of the cooler either forms part of one end of a container or

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forms a foil pack containing the corrosion inhibitor. The film is exposed to the coolant in the vehicle's cooling system by placing it in a tank of the radiator, in the overflow vessel is used for the coolant or in a line that leads to the cooler or comes from it, so that the film is in contact with the coolant.

The present invention further relates to a device for releasing a corrosion inhibitor, in which the container either a glass, plastic or metal part that is open at one or both ends and covered with a film of im is made of essentially the same material as the cooler covering the open ends. The slide is through an adhesive or a screw cap with an opening therein is attached in a suitable manner to the container. If the container is made of metal, a small tab opening in the end can be covered with the foil.

invention
The present / includes the arrangement of a container for a corrosion inhibitor having an opening in one end or an open end covered with an aluminum foil, the radiator being made of brazed aluminum sheet.

The invention further includes the arrangement of a container for a corrosion inhibitor that consists of one less is made of corrodible metal other than aluminum and has one end made of

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Comprises aluminum attached to the container around its periphery and having a notched or knurled portion having in this end to form a limited area of reduced thickness · When the coolant is corrosive the notched area is attacked and corroded to a greater extent than the surrounding area Metal, so that the container is opened earlier and the corrosion inhibitor is released.

The invention further relates to the arrangement of a container in which the corrosion inhibitor is housed in such a way that the inhibitor is released more than once. A foil pack is formed in which the corrosion inhibitor is housed sealingly. This foil pack is part of a larger one, together with another part of the corrosion inhibitor Foil pack housed in a sealed manner, the latter pack in turn together with an additional inhibitor— proportion. is arranged in a sealing manner in a larger pack. As a result, the outer packing corrodes and releases the first Free the corresponding inhibitor content, while the remaining packs are available for further protection at a later point in time. The innermost pack can be a Dye can be added so that the vehicle owner knows that a new package of inhibitor is required.

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Further objects of the present invention are to provide a Construction with the greatest possible simplicity, effectiveness, economy and with the simplest possible mode of action to be provided. These further goals, advantages and possibilities emerge from the detailed description below. One possibility for carrying out the invention is described in detail below in connection with the drawing « Show it:

Figure 1 is a perspective view of a motor vehicle radiator, one possibility of arranging a Container for a corrosion inhibitor shown ietj

Figure 2 is an enlarged side view, partially in section along line 2-2 in Figure 1, showing the assembly of the Shows container;

Figure 3 is an enlarged partial cross-section through a Container for a corrosion inhibitor;

Figure 4 is a side view, partially in section, of a second embodiment of a container;

Figure 5 is a perspective view of a third embodiment a container for a corrosion inhibitor;

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294775?

FIG. 6 is a perspective view of a fourth embodiment of a container for several quantities of inhibitor;

Figure 7 is a cross section taken along line 7-7 in Figure 6; Figure θ is a partial perspective view of a fifth

Embodiment of a container for a corrosion inhibitor;

Figure 9 is a perspective partial view of a sixth

Embodiment of a container for a corrosion inhibitor;

Figure 10 is a partial section along line 10-10 in Figure 9;

Figure 11 is a perspective view of a seventh embodiment of a container for a corrosion inhibitor ι

FIG. 12 shows a vertical section through the container of Figure 11 taken along line 12-12 in Figure 11;

FIG. 13 is a perspective view of an eighth embodiment of a container for a corrosion inhibitor; and

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FIG. 14 shows a vertical section along line 14-14 in FIG.

In Figure 1, a radiator 10 for the cooling system of a motor vehicle engine (not shown) is shown. The cooler comprises an inlet tank 11 and an associated inlet hose 12, an outlet tank 13 with an extending from this outlet tube 14 and a heat exchanger core I5 _t of a plurality vun between the inlet tank and the outlet tank extending and these tubes interconnecting and heat exchange fins between the Pipes which allow air to pass between the pipes, but which interrupt this line in order to prevent heat exchanges.

having.

to improve the efficiency of the cooler / The inlet tank is also provided with an inlet neck which is closed by a pressure cap 15 and with which a conventional overflow pipe (not shown) is connected so that coolant can flow in the radiator to the overflow reservoir. With the cooler it can be a pitfall killer, as shown, or one Cross-flow cooler.

As can be seen in Figures 1 and 2, is in the inlet tube 12 a T-Verbii.dung 17 is used. This can be done either by you Linde attaching it over the hose, with one opening IG err, hose with the hanging one Leg 19 of the connection is in connection, or by Insertion of the connection into a break in the hose

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(Not shown). The depending leg 19 takes a container 21 for a corrosion inhibitor either in solid or liquid form and seals the upper end 22 of the container by a screw thread 23 (see FIG. 2) or by an external clamp (not shown). The T-connection can be arranged in the outlet hose 14 in the same way. The container shown in Figures 2 and 3 is a sleeve 24, which is closed at the bottom and at the upper end is open. The can is made of a suitable glass or plastic material that will keep the temperature of the heated Liquid and can withstand the temperatures under the hood. The top of the sleeve is with provided with an external thread 25 so that a connection with a threaded cap 26 having a central opening 27 can be made. Over the open end of the with a Corrosion inhibitor 29 filled sleeve 24 is a piece of a metal foil 28 which is deformed over the thread 25. The cap 26 is screwed onto the can to seal the film located on the can, with one or more Rubber seals in the cap may be required to improve the seal.

The engine coolant is preferably a 50:50 mixture of ethylene glycol and water with a Corrosion inhibitor in ethylene glycol. This mixture is circulated by a pump from the radiator 10 through the engine block for cooling purposes. The coolant heated by the engine block

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is returned to the cooler and there via an air stream cooled by the cooler core 15 and around the pipes connecting the tanks 11 and 13. When the liquid through the inlet tube 12 flows, it comes into contact with the metal foil 2Θ on the container. If there is a leak in the cooling system or if If a hose breaks, the owner of the motor vehicle becomes the owner most likely replenish the coolant with water from a readily available source. This water is natural not treated and consequently has a corrosive effect on the metal of the cooler.

Since the metal foil 2Θ is essentially the same Material acts as in the cooler construction and because this film is considerably thinner than that forming the cooler Sheet metal material, the corrosive water tends to attack the foil when flowing through the hose 12, so that the foil corrodes at the same or faster speed than the cooler, depending on the type the alloy used. If the film has been eaten through, the coolant dissolves a solid inhibitor and / or introduces a liquid inhibitor into the coolant flow, thus preventing corrosion in the cooling system present metals is stopped or delayed.

For the usual cooling system made of copper-brass, a copper foil is used to seal the sleeve 24. if If an aluminum cooler is used instead of the copper-brass cooler, it is advisable to use an aluminum foil

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employ · For an aluminum radiator the corrosion problem plays a very important role, since aluminum is corroded faster corrosion than copper-brass · Tests were carried out using a Glesfläschchens with an aluminum foil having a thickness of 0.75 mils over the open end and a corrosion inhibitor from either disodium hydrogen

H
phosphate or lithium nitrate. The tests were carried out at room temperature, with the film containing a standard antifreeze solution and corrosive water containing 300 ppm of chlorine ions as

was exposed. Contained sodium chloride and 1.0 ppm copper ions / According to some Days an analysis of the antifreeze showed no change in the disodium hydrogen phosphate or lithium nitrate in the antifreeze while the corrosive water in each case a significant increase in the concentration of the special Inhibitors

In FIG. 4, a second embodiment of a container for the corrosion inhibitor is shown, in which a glass or plastic tube 31 which is open at both ends is used. Each end is covered with a suitable metal film 32, which is sealed at the edges 33, by being connected using a fast curing epoxy resin to the container or glued using a Pliobond (rubber-based) -Klebemittels therewith. Other suitable adhesives are silicones, acrylic resins or cyanoacrylates.

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In Figure 5 is a third embodiment of a container shown for a corrosion inhibitor, which together with the inlet tank 11 of the cooler 10 or in the overflow tank (not shown) can be arranged. This container is one made up of two sheets of a suitable film 35 formed packing, which are sealed around all four edges 36 and a predetermined amount of corrosion inhibitor 37 have. The edges are attached using a suitable adhesive or by mechanical means, for example by ultrasonic welding, sealingly connected to each other. In the case of cyclical temperature conditions, a double-sealed Aluminum foil pack may be required. To achieve this, film strips are folded over the original package edges 36 and then using a suitable adhesive or mechanical devices with the hands sealingly connected.

A fourth embodiment of a container 3b is shown in FIGS. sion inhibitor when it is in the cooler tank or Overflow container is arranged. This container consists of a first filling pack 39, which has a predetermined amount of the corrosion inhibitor 41, a second foil pack 42, in which the first pack 39 together with a second set of inhibitor 43 is arranged, and a third film pack 44, in which the second pack 42 together arranged with a third quantity of inhibitor

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is. All three packs 39, 42 and 44 can be individually sealed to one another along their edges 46, as shown in Figure 7, or all three packages can be joined together along common edges (not shown) at the same time be sealingly connected "

With this container 3Θ the corrosion inhibitor is more than released once when the corrosive effect of the coolant changes. When the container 3Θ is first introduced into the ethylene glycol-water mixture, the outer foil pack 44 is not attacked. When the corrosive effect of the coolant increases, the outer foil pack corrodes and releases the inhibitor 45. The inner packings remain intact and provide additional protection, if this is necessary at a later point in time. If the effectiveness of the inhibitor decreases, the second will corrode Foil pack 42 and releases the inhibitor 43 and finally the inner foil pack 39 corrodes, whereby the inhibitor is released. A dye can be added to the inhibitor 41 in the pack 39 in order to provide a visual signal Is available indicating that a new package of inhibitor is required.

In Figure θ is a fifth embodiment of a container 47 shown, which can be inserted into the T-connection 17 of FIG. This container consists of a steel or Aluminum body 48 which is normally drawn such that

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an integral side wall is formed with the bottom, or the is provided with a separate floor attached to the side wall. A lid 49 is at the top of the body 48 attached by a conventional flanging process as shown at 51. An opening 52 is provided in the metal cover, which can be designed as shown with dashed lines in Figure θ, or the opening can be a act usual pull tabs or overpressure lock opening. A piece of a film 53 is arranged over the opening 52 and attached around the edges by means of a suitable adhesive or by mechanical means. In this embodiment, the foil 53 is exposed to the corrosive liquid eaten away so that the liquid can penetrate the can body 48 to come into contact with the inhibitor and / or to loosen it and introduce it into the cooling system.

In Figures 9 and 10, a sixth embodiment of a container 54 is shown, which has a drawn steel or Has aluminum body 55 in which the corrosion inhibitor 56 is arranged. The body has an open end, which is covered with a sheet of material 57, which corresponds substantially to the cooler material, the one Corrosion protection required. The material 57 is notched or knurled at 58 to define lines of material or bands of material to form, which have a smaller thickness than the sheet metal of the lid, and the lid is on the body via a flange attached at 59. The container can also be in the T-joint

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of Figure 1 are arranged. If he's a corrosive one If cooling liquid is exposed, the notched portion 58 of the lid 57 will penetrate before the remainder of the lid Corrosion corrodes, so that the coolant penetrates into the container through the opening of this notched section and the corrosion inhibitor in the container is released.

The rate of release of the corrosion inhibitor can be controlled by the depth of the notch and / or by the

Element use a galvanic / increased. The cover 57 can furthermore be made of a metal alloy which is the same as that of the cooler, but which is more susceptible to corrosion.

In Figures 11 and 12, a seventh embodiment of a container 61 is shown, which corresponds to the container 54, with the exception of a series of partitions 66, 67 and 68, respectively

e
have an indented or knurled portion 69 · The container 61 comprises a drawn side wall 62 with a base wall 63 formed in one piece with it or attached thereto and a top wall 64 which is made of a material which essentially corresponds to the cooler material! that needs corrosion protection. The top wall has a notched or knurled portion 65 which is corroded or eaten away from the remainder of the top wall.

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The partitions 66, 67 and 68 serve to keep the total amount of the corrosion inhibitor into four separate quantities 71, 72, 73 and 74, which are released one after the other. When thus the top wall 64 of the container 61 the coolant is exposed and the concentration of corrosion inhibitors drops below a predetermined value or the corrosiveness of the coolant increases, the notched portion becomes 65 eaten away until the coolant through an opening formed in this way in the wall with of the inhibitor quantity 71 can come into contact and the inhibitor is thus released into the coolant flow. This The cycle repeats itself at each partition 66, 67 and 6Θ, so that a suitable level of corrosion inhibitor can be sustained over an extended period of time. Although shown as the only container wall 62 with partitions, the container can also consist of several individual containers which are connected to one another in such a way that the wall 62 consists of four short cylindrical wall sections, with the top wall or a partition wall at the end of each short one Container forms.

In Figures 13 and 14, an eighth embodiment is one Container unit shown, which corresponds to the film pack of FIGS. 6 and 7. This unit falls over an inner container 75, which is provided with a cylindrical side wall 76, a bottom wall 77 and a top wall 7b, which are attached to each other are attached. The container is equipped with a corrosion inhibitor

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filled. The top wall is provided with a notched or knurled section 79. An intermediate container 82, which has a side wall B3, a bottom wall 84 and a top wall 85 with a notched portion 6 6 , receives the inner container 75 and a second quantity of the inhibitor B7. An outer container 88 also has a side wall b9, a bottom wall 91 and a top wall 92 with a notched portion 93. This container holds the intermediate container 62 and the inner container 75 as well as a third quantity of the inhibitor 94. This embodiment ensures sequential addition of the corrosion inhibitor in essentially the same manner as the embodiment of FIGS. 6 and 7.

Of the various corrosion inhibitors, some salts have the property of changing from the anhydrous to the hydrate. salt state to expand, so that by this expansion in a container with one end covered by a film or ends covered with foils, the foil is pushed out or the container itself bursts, so that a very rapid release of the inhibitor into the cooling system takes place. Such a salt is, for example, anhydrous disodium hydrogen phosphate. Similar salts are sodium acetate, sodium metaborate, sodium tetraborate, sodium carbonate, sodium chromate, Sodium molybdate, sodium phosphate, sodium pyrophosphate, sodium silicate and sodium sulfate. Organic polymers, which are water-soluble or water-absorbent and expand

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can be dated are, for example, cellulose products, polyacrylic acid, Polyacrylamide and poly (ethylene oxide).

Another method of destroying the foil, once it has been weakened by corrosion, consists in the arrangement of a compressed coil or leaf spring in the container provided with the inhibitor. The spring has such a strength that it is compressed when the

so that the foil is connected to the container / that the foil is there tears open and / or pushes out the inhibitor when the film is weakened by corrosion.

Although the present invention has been described in connection with the regulation of corrosion resistance in a cooling system for a motor vehicle, the system can also be used in other heat exchange systems in which ethylene glycol or a similar coolant is provided as a heat exchange medium.

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L e r s e i t e

Claims (1)

Claims (1 · Procedure for adding a corrosion inhibitor to a « Cooling system if the coolant becomes corrosive, marked by the steps of: producing a container (21) for receiving the corrosion inhibitor, providing at least one Part (28) of the container made of essentially the same material as that of the heat exchanger, in which corrosion is to be prevented, but thinner than that of the heat exchanger forming metal sheet, and exposing the container part provided with the same metal as the heat exchanger to the Coolant, so that when the corrosive swirl of the coolant rises, the container part is attacked until a Penetration of the material occurs and the corrosion inhibitor is released. 2. Device for the automatic addition of a corrosion inhibitor to a cooling system to protect a heat exchanger exposed to corrosion, characterized by a / 2 ORIGINAL INSPECTED Container (21) for the corrosion inhibitor (29), which has at least one part (28) which is made of a metal which is essentially identical to that of the mu-meter exchanger and which is arranged in the cooling system in such a way that the container part ( 28) is exposed to the flow of plastic. 3 · Device according to claim 2, characterized in that the Container part (28) is formed from a metal foil which corrodes faster than the heat exchanger if it is in contact with the corrosive liquid 4. Apparatus according to claim 3, characterized in that the container is a foil pack (34) in which a predetermined amount of the corrosion inhibitor (37) is arranged. _a 5. Apparatus according to claim 4, characterized in that the foil pack (39) and a second amount of the corrosion inhibitor are housed tightly in a larger foil pack (42) and that this pack and a third amount of the inhibitor (45) tightly in a third foil pack (44) are housed. / 3 030023/0838 6. Apparatus according to claim 4, characterized in that it the container is a glass or plastic tube (24) which is provided with a metal foil (28) which covers one or both ends of the tube and seals with it connected is· 7. Apparatus according to claim 4, characterized in that it the container is a metal sleeve (48) having an opening (52) in one end surface (49), and that a metal foil (53) covers the opening (52) and is glued to the end face around the opening Θ. Device according to claim 2, characterized in that it the container (54) is a metal sleeve (55) having an integral closed end therewith and having an opposite open end and a lid (57) formed from a metal that is substantially is identical to the metal of the heat exchanger and is sealed onto the open end of the liner 9. The device according to claim 8, characterized in that the cover (57) is notched (58) or knurled in order to provide a limited section of a smaller thickness than the rest of the cover. 030023/0838 10. Apparatus according to claim 9, characterized in that it at least one partition (76, 67) or (6θ) in the container (61), which consists of the same material as the lid and is notched in the same way as this (69) or knurled 1st. 11. The device according to claim 10, characterized in that the Partition walls (76, 67, 66) split the corrosion inhibitor in the container into a large number of individual quantities (71, 72, 73, 74) that are released one after the other into the cooling system. 12. The device according to claim Θ, characterized in that a second smaller container (Θ2), which is essentially identical to the first container (88) and contains a corrosion inhibitor (87), inside the corrosion inhibitor (94) of the first container is arranged. 13. The apparatus according to claim 12, characterized in that a third smaller container (75) with the first and second container (82, 88) is substantially identical and contains a corrosion inhibitor (61), is arranged within the corrosion inhibitor (87) in the second container (62). / 5 030023/0838