JPS5914606B2 - Method and device for adding corrosion inhibitor to coolant system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for automatically adding corrosion inhibitors to a coolant system or system.

Engine coolants for automotive cooling systems typically contain ethylene glycol and small amounts of diethylene glycol. This fluid is diluted with water to provide a glycol concentration of 5070 or less depending on the desired freezing point for the coolant system. Most companies that manufacture and/or distribute ethylene glycol for coolant systems use corrosion inhibitors in the solution to prevent corrosion of the copper-brass customarily used in the manufacture of automotive radiators. agent is added. These inhibitors typically contain benzotriazole and one or more inorganic salts such as phosphates, borates, nitrates, nitrites, silicates or arsenates to prevent copper corrosion. , tolyltriazole or mecaptobenzothiazole.

This solution is generally moderated to a pH of 8 to PHlO to reduce corrosion of iron and neutralize the glycolic acid formed in the oxidation of ethylene glycol. Most companies recommend servicing their antifreeze coolant every one or two years at most, or the average car owner should maintain their coolant system at around -29°C (-29°C). It has been found that many owners do not follow the owner's instruction manual to maintain the protection of 20'F) and do not test the coolant to determine whether the coolant is rusty or dirty. When the antifreeze coolant runs out due to a leak or a broken hose, simply add water. This is more common in the southern regions than in the northern regions. In normal passenger car maintenance, 2570 cars require maintenance of their coolant system after one year, and as many as 50% of cars require maintenance of their coolant system after two years. In conventional copper-brass radiators, as well as in aluminum equipment, the antifreeze or coolant mixture contains 50-55% ethylene glycol with a suitable corrosion protection treatment. Corrosion of metals increases significantly when the mixture is diluted to 33% ethylene glycol and 67% water.
This is particularly important in high temperature coolant systems, which are becoming more common with the increasing use of ncOntrOls). Also, the total number of gas miles for a new car (Gasmile).
Due to the strong emphasis on the age of cars, cars are made smaller and lighter by using lightweight metals or plastics in place of iron or copper where practical.

Aluminum radiators are being used in automotive coolant systems to replace the conventional copper-brass radiators used heretofore. As previously mentioned, aluminum radiators are susceptible to the corrosive effects of coolants or antifreezes that have a low percentage of ethylene glycol and/or a sufficient amount of corrosion inhibitor in the coolant. In such equipment, additional corrosion inhibitors should be added, otherwise the aluminum will corrode rapidly due to pitting. The present invention ameliorates this corrosion problem by automatically adding corrosion inhibitors to the coolant under corrosive conditions. SUMMARY OF THE INVENTION The present invention provides an apparatus for automatically adding a corrosion inhibitor when the corrosivity of a motor vehicle engine coolant reaches or exceeds a predetermined level;
It has a closed container for the solid or liquid corrosion inhibitor that has at least a portion made of substantially the same material as the heat exchanger or radiator through which the coolant passes and which corrodes.

This part of the container is made of ethylene, which has been appropriately treated to prevent corrosion.
When the coolant becomes corrosive, although it is not corrosive in a glycol and water mixture solution, the corrosive parts of the vessel corrode at a rate equal to or faster than the rate of corrosion of the radiator. If the corrosive material is thinner than the radiator material, it will quickly perforate and release the corrosion inhibitor into the coolant system. The present invention further provides a method for releasing the corrosion inhibitor into the coolant system, wherein the foil of material forming the radiator forms part of one end of the container or forms a foil packet containing the corrosion inhibitor. Regarding equipment.

The foil can be inserted into the radiator tank so that the foil is in contact with the coolant, in the cooling system of the vehicle, in an overflow container for the coolant or in the flow path leading to or from the radiator. Exposure to coolant. The present invention further includes:
The present invention relates to a device for releasing corrosion inhibitors, in which the container consists of a glass, plastic or metal member which is open at one or both ends and whose open end is covered with a foil of approximately the same material as the radiator.

The foil is suitably secured to the container by adhesive or by a threaded top with an aperture. If the container is metal, the small tab opening at the end is covered with foil. SUMMARY OF THE INVENTION It is an object of the present invention to provide a container for a corrosion inhibitor in a cooling device in which the radiators are made of aluminum plates brazed together and having an open end at one end or covered with aluminum foil. It is in. Another object of the invention is for a corrosion inhibitor molded of a metal less corrosive than aluminum, having an aluminum end fixed to the container along the periphery and having a notch or indentation defining a reduced thickness section. Our aim is to provide containers for

When the coolant becomes corrosive, the notched areas become attacked and corrode by pitting at a faster rate than the surrounding metal so as to pit early and release the corrosion inhibitor. Yet another object of the invention is to provide a container containing a corrosion inhibitor for one or more releases of the corrosion inhibitor.

The foil envelope or bucket is sealed with a corrosion inhibitor inside. This foil packet is sealed in a larger foil packet with another corrosion inhibitor, and this foil packet is further sealed in a larger foil packet with another corrosion inhibitor. Thus, the outer foil packet is corroded first and its The corrosion inhibitor is released and the remainder can be utilized for later protection. A dye may be used in the innermost packet to indicate to the owner that a new packet of corrosion inhibitor is needed. Still another object of the present invention is to have the simplest structure, best efficiency,
The object of the present invention is to provide an economical and easy-to-operate device for automatically adding a corrosion inhibitor to a coolant system.

Embodiments of the present invention will be described below with reference to the drawings.

In the figures illustrating an embodiment of the invention, FIG. 1 shows an automobile radiator 10 for a coolant system or system of an automobile engine (not shown).

The radiator includes an inlet tank 11 having an inlet hose 12;
An outlet tank 13 with an outlet hose 14 and tubes extending between and connected to the inlet and outlet tanks to allow air flow between the tubes or to increase the heat exchange characteristics of the radiator. and a heat exchange core 15 having folded and undulating heat exchange fins to block upward air flow. The inlet tank is provided with an inlet neck closed by a pressure lock-up 16 and a conventional overflow tube (not shown) is connected to the neck to allow coolant in the radiator to overflow into the overflow container. There is. The radiator may be of the down-flow type as shown or of the cross-flow type. 1 and 2, by fitting sealingly from the outside of the hose such that the T-connector 17 communicates with the opening 18 in the hose or the depending leg 19 of the connector. Alternatively, it may be inserted into the inlet hose by inserting the connector into a cut in the hose (not shown).

The depending leg 19 receives a container 21 for a solid or liquid corrosion inhibitor and fastens the upper end 22 of the container by a screw 23 (FIG. 2) or by an external fastener (not shown). It is surrounded and sealed. The T-connector is adapted to be equally attachable to the outlet hose 14. The container shown in Figures 2 and 3 is a closed-bottom, open-top shear or bottle made of a suitable glass or plastic material capable of withstanding the temperature of the heated liquid and the temperature within the engine compartment. It is 24.

The top end of the bottle is fitted with a threaded cap 26 having a central opening 27.
It has an external thread 25 for use. A piece of metal foil 28
It is placed over the open end of a shear or bottle 24 filled with corrosion inhibitor 29 and superimposed on the screw 25. The cap 26 is threaded onto the bottle to fit the foil on the bottle, and one or more rubber gaskets may be required within the cap to improve the seal. The engine coolant is preferably a 50/50 mixture of ethylene glycol and water with a corrosion inhibitor in ethylene glucol as supplied to motor vehicle owners.

This mixture is circulated from the radiator 10 by a fluid pump through the engine block for cooling. Coolant heated by the engine block is returned to the radiator for cooling by forced airflow through the radiator core 15 around the tubes connecting tanks 11 and 13. As the liquid passes through the inlet hose 12, it contacts the metal foil 28 of the container 21. When a leak occurs in a coolant system or a hose breaks, owners often replace the coolant with water from a readily available source. This water is untreated (as a coolant) and likely corrodes the metal of the radiator. If the metal foil 28 is the same material as the radiator structure and significantly thinner than the material forming the radiator, the corrosive water will attack the foil as it passes through the hose 12, and the foil will be the same material as the radiator due to its alloy composition. It will corrode faster than that.

When the foil is punctured, the coolant dissolves the solid inhibitor and/or allows the liquid inhibitor to flow into the coolant stream to stop or retard corrosion of metal in the coolant system. For conventional copper-brass radiator systems, copper foil is used to seal the bottle 24. Similarly, if an aluminum radiator or a copper-brass radiator is being replaced, aluminum foil may be used. Corrosion issues are most important for aluminum radiators because the rate of corrosion due to pitting is faster than for copper-brass radiators. Tests were conducted using glass bottles with the open end surrounded by 0.75 Mil thick aluminum foil and a corrosion inhibitor of either disodium hydrogen phosphate or lithium nitrate. The test is,
Expose the foil to a normal antifreeze solution, such as sodium chloride.
Exposure to corrosive water containing 00 ppm chloride and 1.0 ppm copper ions was carried out at room temperature. After a few days, analysis of the antifreeze showed no change to the sodium hydrogen phosphate or lithium nitrate in the antifreeze, while the corrosive water showed a noticeable increase in the concentration of the particular inhibitor in each case. Indicated. FIG. 4 shows a second embodiment of a container for a corrosion inhibitor using a glass or plastic tube 31 open at both ends, each end of which is covered with a suitable metal foil and fast-curing epoxy. Edge 3 by bonding using glue with resin or PllObOnd (rubber based) adhesive.
It is sealed with 3.

Other suitable adhesives consist of silicone, allyl acid or allyl cyanide. FIG. 5 shows a third embodiment of a container for corrosion inhibitor, which is adapted to be placed in the inlet tank 11 of the radiator 10 or in the overflow tank (not shown).

The container is wrapped and molded from two sheets of suitable foil 35 sealed on all four sides 36 and containing a predetermined amount of corrosion inhibitor therein. The edges are sealed with a suitable adhesive, and mechanical means such as ultrasonic welding may also be used. Double sealed aluminum foil packaging is required under seasonal temperature conditions. To accomplish this, the sheet or foil is folded over the edge 36 of the original wrap or foil packet and then sealed to the edge using a suitable adhesive or mechanical means. 6 and 7 illustrate a fourth embodiment of a container 38 which is adapted to receive one or more charges of corrosion inhibitor when placed in a radiator tank or overflow container.

The container includes a first package or foil packet 39 containing a predetermined amount of corrosion inhibitor 41 and a second package or foil packet containing the first package 29 along with a second charge of corrosion inhibitor 43. 42 and a third package or foil bucket 44 containing the second package along with a third charge of corrosion inhibitor 45. All three packets 39, 42 and 44 can be sealed at each individual edge 46 as shown in FIG. 7, or simultaneously along a common edge (not shown).

In this container 38, the corrosion inhibitor is released one or more times when the corrosivity of the coolant changes.

When the container 38 is first introduced into the ethylene glycol and water mixture, the outer wrapper will not be attacked. As the coolant becomes more corrosive, the outer envelope corrodes and the corrosion inhibitor 45 is released. The inner wrapper can be left in place for further protection if needed at a later date. When the effectiveness of the corrosion inhibitor decreases, the second packet 4
2 corrodes to release the corrosion inhibitor 43, and then the inner wrapper 39 corrodes to release the corrosion inhibitor 41.
A colored dye may be added to the corrosion inhibitor 41 in the packet 39 as a visual signal to indicate that a new packet of corrosion inhibitor is needed. FIG. 8 shows a fifth embodiment of the container 47 to be inserted into the T-connector 17 of FIG.

The container consists of a steel or aluminum body 48, which is typically pultruded to provide one-piece side walls and a bottom, or a separate bottom may be secured to the side walls. Top 49
is secured to the upper end of the body 48 by conventional flange action such as at 51. The metal top 49 is formed with an opening 52 as shown in broken lines in FIG.
The opening may be of the conventional "Pull-Tab" or "POptOp" type. A piece of foil 53 is placed over the opening 52 and secured around the edges by suitable adhesive or mechanical means. In this embodiment, the foil 53 is attacked by the corrosive liquid and pits, and the liquid penetrates into the body 48 and contacts the corrosion inhibitor and (
or) allowing the inhibitor to dissolve and flow into the refrigerant system. Figures 9 and 10 show corrosion inhibitor 5 inside.
A sixth embodiment container 54 is shown having a pultruded steel or aluminum body 55 receiving 6 IU.

The body has an open end covered with a plate of substantially the same material as the radiator requiring corrosion protection. The top material 57 is scored or recessed at 58 to form a line or band of reduced wall thickness than the rest of the top. This container is adapted to be received within the T-connector 17 of FIG. Notched portion 5 of top 57 when exposed to corrosive coolant
8, the corrosion pits are pitted before the rest of the top, and the erosion of this score area allows the coolant to enter the container and release the corrosion inhibitor therein. The rate of corrosion inhibitor release is controlled by the depth of the indentation and/or increased by the use of electrical couplings.

The top 57 may also be formed of the same metal alloy as that of the radiator, but may be made of a more corrosive metal alloy. 11 and 12 show several partition walls 66, 6 each having a notch or recessed portion 69.
A seventh embodiment of a container 61 is shown which is similar to container 54 with the exception of 7 and 68. The container 61 has a pultruded side wall 62 with an integral or attached bottom wall 63.
and a top wall 64 made of substantially the same material as that of the radiator requiring corrosion protection. The top wall has a notched or recessed portion 65 that pits or erodes more quickly than other portions of the top wall. Partition walls 66, 567 and 6
8 divides the corrosion inhibitor into four separate sections 71, 72, 73 and 74 that are sequentially released.

Thus, when the top wall 64 of the container 61 is exposed to a flow of coolant and the concentration of the corrosion inhibitor decreases below a predetermined level or the corrosivity of the coolant increases, the scored portion 65
Pitting or corrosion occurs until the wall is punctured and the refrigerant contacts portions of corrosion inhibitor 71, releasing the inhibitor into the refrigerant flow. This cycle is performed on each partition wall 66, 67 and 68 in turn to maintain adequate corrosion inhibitor levels over an extended period of time. Although shown as a single container wall 62 with an intermediate partition wall, the container has walls 62
It can be formed as several separate containers joined together into four short cylindrical sections with a partition wall forming the top wall or end of each short container. 13 and 14 illustrate an eighth embodiment of a container assembly similar to the foil packet assembly of FIGS. 6 and 7.

The assembly includes an inner container 75 having a cylindrical side wall 76, a bottom wall 77 and a top wall 78 fixed to the side walls and filled with a corrosion inhibitor 81. The top wall is provided with a notched or recessed portion 79. An intermediate container 82 having side walls 83, a bottom wall 84, and a top wall 85 with a notched portion 86 contains an inner container 75 and a second corrosion inhibitor 87. Outer container 88 has side walls 89, a bottom wall 91 and a top wall 92 with a notched portion 93, and the container contains intermediate and inner containers 75 and 82 and a third corrosion inhibitor. This embodiment provides continuous corrosion inhibitor application much like the embodiment of FIGS. 6 and 7. Among the various corrosion inhibitors, some exhibit the property of salt expansion from anhydrous salts to hydroxide salts, and this expansion within a foil-covered container can push the foil out or crack the container. This has the effect of rapidly releasing the corrosion inhibitor into the refrigerant system.

One such salt is anhydrous sodium hydrogen phosphate. Other salts that expand when hydrated include sodium acetate,
Sodium metaborate, sodium borate, sodium carbonate, sodium chromate, sodium molybdate,
Sodium phosphate, sodium pyrophosphate, sodium silicate and sodium sulfate. Organic polymers that are soluble or swellable in water and that swell when hydrated include cellulose products, polyallyl acid, polyacrylamide, and polyethylene oxide. Another method of destroying the foil once it has been weakened by corrosion is to provide a compression coil spring or leaf spring with a corrosion inhibitor in the container.

The spring is a length that is compressed when the foil is sealed to the container, but opens the foil when the foil is weakened by corrosion and (
or) extrude corrosion inhibitors. Although the present invention is shown for controlling corrosion resistance in automotive coolant systems, the device may be used in other heat exchange systems where ethylene glycol or other similar coolants are used as the heat exchange medium. may also be used.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an automotive radiator showing one method of positioning a corrosion inhibitor container in conjunction with an automotive radiator; FIG. 2 is a view of the container taken along line 2--2 of FIG. 3 is an enlarged sectional view of an enlarged portion of a container for corrosion inhibitor; FIG. 4 is a partial sectional view of a second embodiment of the container; FIG. 5 is a perspective view of a third embodiment of a container for corrosion protection; FIG. 6 is a perspective view of a fourth embodiment of a container for loading multiple corrosion inhibitors; FIG. FIG. 8 is a perspective view of a fifth embodiment of a corrosion inhibitor container; FIG. 9 is a perspective view of a sixth embodiment of a corrosion inhibitor container. 10 is a partial cross-sectional view taken along line 10--10 of FIG. 9, FIG. 11 is a perspective view of a seventh embodiment of the corrosion inhibitor container, and FIG. 12 is a partial sectional view taken along line 12-- of FIG. 11. 13 is a perspective view of the eighth embodiment of the corrosion inhibitor container, and FIG. 14 is a cross-sectional view of the container along line 13.
14 is a cross-sectional view taken along line 14-14 of the figure; FIG. 10: Radiator, 11: Inlet tank, 12: Outlet tank, 17: T connection, 21, 34, 38, 47, 5
4, 61, 75, 82, 88: container, 28, 53: foil,
58, 65, 69, 79, 87, 93: Pig 1st, 29
, 37, 41, 43, 45, 56: Corrosion inhibitor, 71,
72, 73, 81, 87, 94: Corrosion inhibitor.

Claims (1)

[Scope of Claims] 1. A method for adding a corrosion inhibitor to a coolant system when the coolant becomes corrosive, the method comprising forming a container 21 containing the corrosion inhibitor and preventing corrosion from occurring. Providing at least a metal part in the container that is almost the same metal as the heat exchanger but thinner than the metal members forming the heat exchanger, so that when the corrosiveness of the coolant increases, the coolant enters and prevents corrosion. A method of adding a corrosion inhibitor to a coolant system comprising exposing a portion of said container of the same metal as the heat exchanger to the coolant such that the portion of the container is attacked until the agent is released. 2. A device for automatically adding a corrosion inhibitor to a coolant system to protect a heat exchanger 15 subject to corrosion, the device comprising at least a portion 28 of substantially the same metal as that forming the heat exchanger. a container for a corrosion inhibitor 29 with a container configured to automatically apply the corrosion inhibitor to the coolant system, the container being arranged in the coolant system such that a portion 28 of the container is exposed to the flow of the coolant; equipment to add to. 3. Automatically applying a corrosion inhibitor to the coolant system according to claim 2, wherein the container portion 28 is made of a metal foil that corrodes more rapidly than the heat exchanger when in contact with corrosive liquids. equipment to add to. 4. Apparatus for automatically adding corrosion inhibitor to a coolant system as claimed in claim 3, wherein said container is a foil packet 34 containing a predetermined amount of corrosion inhibitor 37 therein. 5. A second charge of corrosion inhibitor and the foil packet 39 are both sealed in a large foil packet 42, and a third charge of this packet of corrosion inhibitor is sealed together in a third foil packet 44. 5. An apparatus for automatically adding corrosion inhibitor to a coolant system as claimed in claim 4. 6. Apparatus for automatically adding corrosion inhibitor to a coolant system as claimed in claim 4, wherein said container is a glass or plastic tube 24 covered at one or both ends with metal foil 28 and sealed to a tube. 7. Claim 4, wherein the container is a metal can 48 having an opening 52 on one end surface 49, and a metal foil 53 covers the opening 52 and is joined to the end surface around the opening.
A device for automatically adding corrosion inhibitors to a coolant system as described in . 8. Claims in which the container 54 is a metal can 55 having an integral closed end and an opposite open end, and a lid 57 made of substantially the same metal as the heat exchanger is sealed to the open end of the can. 2. A device for automatically adding a corrosion inhibitor to the coolant system according to item 2. 9. Automatically applying a corrosion inhibitor to the coolant system according to claim 8, wherein said lid 57 is notched or recessed to provide a limited area of thinner thickness than other parts of the lid. equipment to add to. 10. Claim 9, further comprising at least one partition wall (66, 67 or 68) in the container 61, which is made of the same material as the lid and is indented or indented in the same way as the lid. A device that automatically adds corrosion inhibitors to the described coolant system. 11. Claim 10, wherein the partition walls 66, 67, 68 divide the corrosion inhibitor therein into a plurality of charges 71, 72, 73, 74 to be added successively to the coolant system. A device that automatically adds corrosion inhibitor to the cooling system of a vehicle. 12. A second small container 82, substantially similar to the first container 88 and containing a corrosion inhibitor, is disposed within the corrosion inhibitor within the first container. A device that automatically adds corrosion inhibitors to the coolant system of a vehicle. 13 A third small container 75, substantially the same as the first and second containers 82, 88 and containing a corrosion inhibitor 81, is placed within the corrosion inhibitor 81 in the second container 82. 13. An apparatus for automatically adding corrosion inhibitor to a coolant system as claimed in claim 12.