JP2011074824A - Metal ion removal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend the service life of a metal ion removal device 1 while removing the metal ion contained in fuel without enlarging the device. <P>SOLUTION: The metal ion removal layer 12 of the metal ion removal device 1 includes two layers, upstream and downstream layers 13, 14. The upstream and downstream layers 13, 14 are respectively formed while being filled with weak and strong acid ion exchange resins as metal ion trapping material. Since the types of trappable metal ions are increased in the downstream layer 14 in comparison with the upstream layer 13, the types of metal ions to be trapped in both the layers 13, 14 are trapped and removed in the upstream layer 13. Thereby, the types of the metal ions led to flow into the downstream layer 14 are the types of metal ions not to be trapped in the upstream layer 13. Then, various types of metal ions are efficiently removed. Thus, the service life of the metal ion removal device 1 can be extended without enlarging the device. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a metal ion removing apparatus that removes metal ions contained in a fuel.

Conventionally, a fuel supplied to an internal combustion engine or the like contains a trace amount of metal ions as impurities, while a fatty acid such as oleic acid is added as a lubricant. For this reason, in the fuel, a salt reaction may occur between these metal ions and the fatty acid, and a fatty acid metal salt may be generated. Since the fatty acid metal salt is generally insoluble in fuel, for example, the fatty acid metal salt may deposit on the sliding portion of the injector and cause malfunction.
Therefore, a technique for arranging a metal ion removing device for removing metal ions in a fuel supply path from a fuel tank to an injector has been studied.

  By the way, removal of metal ions contained in a liquid such as fuel can be performed by the presence of an active site capable of capturing metal ions such as a chelate forming group in a chelate resin and an ion exchange group in an ion exchange resin. And once an active site captures a metal ion, it loses the function of capturing the metal ion, and the metal ion cannot be captured unless the metal ion is removed from the active site by regeneration. For this reason, when the target for removing metal ions is a huge amount of processing over a long period of time like the fuel supplied to the internal combustion engine, it is constantly required to extend the life of the metal ion removal device as much as possible. ing.

  For example, Patent Document 1 discloses a technique related to extending the life of a water purification cartridge that removes metal ions and the like from raw water such as tap water. According to Patent Document 1, this water purification cartridge includes a packed bed filled with activated carbon, a cation exchange resin, an inorganic ion exchange material, and the like, and removes metal ions and the like by passing raw water through the packed bed. To do. And according to Patent Document 1, it is described that by adding a cation exchange resin and an inorganic ion exchange material to the packed bed, it is possible to increase the amount of treatment and extend the life. .

  Patent Document 2 discloses a pure water production apparatus that produces pure water by ion exchange and a method for regenerating the pure water. According to Patent Document 2, this pure water production apparatus comprises a cation exchange tower (KW tower) filled with a weak acid cation exchange resin, a strong acid cation exchange resin and a strongly basic cation exchange resin in the same tower. A mixed bed type ion exchange column (MB column) packed therein is further provided, and a decarboxylation tower (D column) is further provided between the cation exchange column and the mixed bed type ion exchange column.

  And according to patent document 2, a hardness component, an alkalinity component, and carbonic acid can be significantly reduced regarding the water quality supplied to MB tower by arranging KW tower and D tower before MB tower. It is written. Furthermore, according to Patent Document 2, since the water quality supplied to the MB tower can be improved as described above, it is possible to reduce the load on the MB tower and prevent the formation of precipitates, which is regarded as a problem during the regeneration of the MB tower. It is stated that it can be done.

However, the techniques of Patent Documents 1 and 2 are intended to treat water, and the effect on fuel is unknown.
That is, the water purification cartridge of Patent Document 1 purifies tap water and is mainly intended to remove heavy metal ions from tap water. On the other hand, when the purpose is to remove metal ions from the fuel, the metal ions to be removed are not only heavy metal ions.

  Moreover, the pure water manufacturing apparatus and its regeneration method of Patent Document 2 are intended for large-scale pure water manufacturing plants. On the other hand, a metal ion removing device that removes metal ions from fuel is to be mounted on a vehicle or the like, and is significantly smaller than the pure water producing device of Patent Document 2.

JP 2003-340448 A JP-A-7-68254

  The present invention has been made to solve the above-mentioned problems, and its object is to extend the life of a metal ion removing apparatus for removing metal ions contained in fuel without increasing the size of the apparatus. It is in.

[Means of Claim 1]
The metal ion removal device according to claim 1 includes a metal ion removal layer formed of a metal ion scavenger capable of trapping metal ions, and allows the fuel to pass through the metal ion removal layer so that the metal contained in the fuel Ions are removed. The metal ion removal layer is formed by stacking a plurality of layers of different metal ion trapping materials in the fuel flow direction, and the metal ion trapping material forming each layer has a metal ion trappable in the downstream layer. More types.

  As a result, the types of metal ions that can be captured in both the upstream and downstream layers are mainly removed in the upstream layer, so the types of metal ions flowing into the downstream layer are It becomes a kind of metal ion that cannot be captured by the layer. For this reason, metal ions can be efficiently removed from the fuel containing many types of metal ions by increasing the number of types of metal ions that can be captured in the downstream layer.

  That is, since the fuel flowing into the downstream layer is almost free of some types of metal ions in the upstream layer, the downstream layer cannot be captured mainly by the upstream layer. It is sufficient as a function to be able to remove various kinds of metal ions. Therefore, since the amount of the metal ion trapping material to be filled in each layer can be optimized according to the properties of the fuel to be removed, the life is extended without unnecessarily increasing the size of the metal ion removal device. be able to.

[Means of claim 2]
According to the metal ion removing device according to claim 2, the combination of at least one upstream layer and downstream layer among the plurality of layers is an ion exchange in which both layers have acidic ion exchange groups. The body is a metal ion scavenger. Also, the ion exchange groups in the downstream layer are more acidic than the ion exchange groups in the upstream layer.
Strongly acidic ion exchange groups have more types of metal ions that can be removed than weakly acidic ion exchange groups. For this reason, by making the ion exchange group in the downstream layer more acidic than the ion exchange group in the upstream layer, the types of metal ions that can be captured in the downstream layer can be increased.

[Means of claim 3]
According to the metal ion removing device of the third aspect, the ion exchanger in the downstream layer has a smaller total ion exchange capacity than the ion exchanger in the upstream layer.
In the polymer that forms the skeleton of the ion exchange resin, the number of sites where strong acid ion exchange groups can be introduced is smaller than the number of sites where weak acid ion exchange groups can be introduced. The total ion exchange capacity is smaller than the exchange resin. That is, the strongly acidic ion exchange resin has a smaller amount of metal ions that can be captured, although the number of metal ions that can be captured is larger than the weakly acidic ion exchange resin.

  For this reason, the downstream layer must remove metal ions of a type that cannot be captured by the upstream layer with a smaller total ion exchange capacity than the upstream layer. The effect of “the amount of the metal ion trapping material to be filled in each layer can be optimized according to the properties of the fuel” described can be significantly obtained.

[Means of claim 4]
According to the metal ion removing device of the fourth aspect, the ion exchanger is filled as an ion exchange resin and an ion exchange nonwoven fabric to form a layer.
This means shows an embodiment of an ion exchanger.

1 is a configuration diagram of a fuel injection device (Example 1). FIG. It is a principal part block diagram which shows the principal part of a metal ion removal apparatus (Example 1). It is a principal part block diagram which shows the principal part of a metal ion removal apparatus (Example 2). It is a principal part block diagram which shows the principal part of a metal ion removal apparatus (Example 3).

  The metal ion removal apparatus of Embodiment 1 includes a metal ion removal layer formed of a metal ion trapping material capable of trapping metal ions, and allows the fuel to pass through the metal ion removal layer, thereby allowing the metal ions contained in the fuel to pass through. To be removed. The metal ion removal layer is formed by stacking a plurality of layers of different metal ion trapping materials in the fuel flow direction, and the metal ion trapping material forming each layer has a metal ion trappable in the downstream layer. More types.

Further, in the combination of at least one upstream layer and downstream layer among the plurality of layers, both layers use an ion exchanger having an acidic ion exchange group as a metal ion scavenger. Also, the ion exchange groups in the downstream layer are more acidic than the ion exchange groups in the upstream layer.
Furthermore, the ion exchanger of the downstream layer has a smaller total ion exchange capacity than the ion exchanger of the upstream layer.
According to the metal ion removing device of Embodiment 2, the ion exchanger is filled as an ion exchange resin and an ion exchange nonwoven fabric to form a layer.

[Configuration of Example 1]
The structure of the metal ion removal apparatus 1 of Example 1 is demonstrated based on drawing.
The metal ion removing apparatus 1 removes metal ions from fuel injected and supplied to an internal combustion engine (not shown) of a vehicle. For example, as shown in FIG. A part of a pressure accumulating fuel injection device 3 for supplying the injected fuel to the internal combustion engine is constituted.

  The fuel injection device 3 includes, for example, a fuel supply pump 5 that pumps up fuel from the fuel tank 4 and discharges the fuel at a high pressure, and a common rail 2 as a pressure accumulation container that accumulates fuel discharged from the fuel supply pump 5 in a high pressure state. , Mounted in each cylinder of the internal combustion engine, disposed between the injector 6 for receiving fuel distribution from the common rail 2 and injecting the fuel into each cylinder, the fuel tank 4 and the fuel supply pump 5 and included in the fuel An electronic control device that receives input of detection signals indicating the operating state of the internal combustion engine from various sensors and a fuel filter 7 that removes foreign matter, and controls operations of the fuel supply pump 5 and the injector 6 based on these detection signals (Hereinafter referred to as an ECU) 8.

The metal ion removing device 1 is disposed, for example, on the upstream side of the fuel filter 7 between the fuel tank 4 and the fuel supply pump 5 to remove metal ions from the fuel.
In the injector 6, various spaces into which high-pressure fuel accumulated in the common rail 2 is introduced are formed, and various members related to the start and stop of fuel injection, such as a valve body that opens and closes the injection hole, These spaces are displaced in the injector 6 while maintaining a high pressure state. For this reason, since these various members form a sliding portion or the like having a very narrow clearance, if the fatty acid metal salt is deposited on such a sliding portion or the like, the injector 6 may malfunction.

  That is, the fuel supplied to the internal combustion engine contains a trace amount of metal ions as impurities, and a fatty acid such as oleic acid as a lubricant. For this reason, in the fuel, a salt reaction may occur between these metal ions and the fatty acid, and a fatty acid metal salt may be generated. Since the fatty acid metal salt is generally insoluble in fuel, it may be deposited on the sliding portion of the injector 6 and cause malfunction.

  Therefore, according to the fuel injection device 3, for example, between the fuel tank 4 and the fuel supply pump 5, the metal ion removing device 1 is disposed upstream of the fuel filter 7 to positively remove metal ions from the fuel. Is done.

  For example, as shown in FIG. 2, the metal ion removing apparatus 1 includes a metal ion removing layer 12 formed of a metal ion trapping material capable of trapping metal ions in a resin case 11. In FIG. 12, the fuel is passed in the vertical direction from the lower side to the upper side to remove metal ions contained in the fuel. The metal ion removal layer 12 is formed, for example, by stacking two different metal ion trapping material layers 13 and 14 in the fuel flow direction.

  Here, the metal ion trapping material forming the upstream (lower) layer 13 is, for example, a weak acidic ion exchange resin having a carboxyl group as an ion exchange group, and the upstream layer 13 is a weak acidic ion exchange. It is formed by filling a resin as a metal ion capturing material. The metal ion trapping material that forms the downstream (upper) layer 14 is, for example, a strongly acidic ion exchange resin having a sulfonic acid group as an ion exchange group, and the downstream layer 14 is a strongly acidic ion exchange resin. Is filled as a metal ion trapping material.

  That is, since the ion exchange group of the ion exchange resin forming the downstream layer 14 is more acidic than the ion exchange group of the ion exchange resin forming the upstream layer 13, the types of metal ions that can be captured are Many. In addition, in the polymer that serves as the skeleton of the ion exchange resin, the number of sites that can introduce strongly acidic ion exchange groups such as sulfonic acid groups is less than the sites that can introduce weakly acidic ion exchange groups such as carboxyl groups. Therefore, the strongly acidic ion exchange resin has a smaller total ion exchange capacity than the weakly acidic ion exchange resin. For this reason, the ion exchange resin forming the downstream layer 14 has a smaller total ion exchange capacity than the ion exchange resin forming the upstream layer 13.

Thus, the metal ion trapping material that forms the upstream layer 13 is a weakly acidic ion exchange resin, and the metal ion trapping material that forms the downstream layer 14 is a strongly acidic ion exchange resin. Although the layer 14 has a smaller amount of metal ions that can be captured than the upstream layer 13, the number of metal ions that can be captured is increased.
Note that the upper and lower sides of the metal ion removal layer 12 and between the layers 13 and 14 are partitioned or partitioned by a mesh 15 or the like in order to allow the passage of fuel while preventing scattering of the ion exchange resin. .

[Effect of Example 1]
According to the metal ion removal apparatus 1 of Example 1, the metal ion removal layer 12 is composed of two layers, an upper layer and a downstream layer 13 and 14, and the upper and downstream layers 13 and 14 are weak, It is formed by filling a strongly acidic ion exchange resin as a metal ion scavenger.

  Thereby, although the downstream layer 14 has a smaller amount of metal ions that can be captured than the upstream layer 13, the number of types of metal ions that can be captured increases. For this reason, since the types of metal ions that can be captured by both the layers 13 and 14 are mainly captured and removed by the upstream layer 13, the types of metal ions that flow into the downstream layer 14 are: It becomes a kind of metal ion that cannot be captured by the upstream layer 13. For this reason, metal ions can be efficiently removed from a fuel containing many kinds of metal ions.

  That is, since the fuel flowing into the downstream layer 14 is almost free of some types of metal ions in the upstream layer 13, the downstream layer 14 is mainly the upstream layer 13. If the metal ions that cannot be captured can be removed, the function is sufficient. Therefore, the amount of resin to be filled in each of the layers 13 and 14 can be optimized according to the properties of the fuel to be removed, so that the life of the metal ion removing device 1 can be extended without unnecessarily increasing the size. Can be extended.

[Example 2]
According to the metal ion removal apparatus 1 of Example 2, as shown in FIG. 3, the metal ion removal layer 12 is composed of three layers of upper, middle, and downstream layers 17 to 19, and the upstream layer 17 is It is formed by filling a chelate resin having a chelate-forming group as a metal ion scavenger, and the middle and downstream layers 18 and 19 are respectively filled with a weak and strong acidic ion exchange resin as a metal ion scavenger. Is formed.

  The type of chelate resin, that is, the type of chelate-forming group is selected according to the type of metal ion to be removed in the upstream layer 17. Further, the middle and downstream layers 18 and 19 are, for example, a weakly acidic ion exchange resin having a carboxyl group and a strongly acidic group having a sulfonic acid group, as in the downstream layers 13 and 14 of Example 1, respectively. It is an ion exchange resin.

  Here, the chelate resin has a greater selectivity for a specific type of metal ion for each type of chelate-forming group than in the case of an ion exchange resin. That is, the chelate resin preferentially chelates with a specific type of metal ion even when the concentration of the specific type of metal ion is much lower than the concentration of other types of metal ions (for example, one hundred thousand). To capture specific types of metal ions.

  Thereby, the metal ion removal layer 12 exhibits a three-layer structure in which the types of metal ions that can be captured increase toward the downstream side. And after a specific kind of metal ion is removed in the upstream layer 17, the fuel flows into the middle and downstream layers 18 and 19 to remove other kinds of metal ions. For this reason, metal ion removal from fuel can be made more efficient.

That is, the fuel flowing into the middle and downstream layers 18 and 19 is substantially free of specific types of metal ions in the upstream layer 17, so the middle and downstream layers 18 and 19 are not of a specific type. If the metal ions can be removed, the function is sufficient. Accordingly, since the amount of resin to be filled in each of the layers 17 to 19 can be optimized according to the properties of the fuel to be removed, the life can be extended without making the metal ion removing device 1 larger than necessary. Can be extended.
The amount of resin to be filled in each of the middle and downstream layers 18 and 19 can be optimized in the same manner as the metal ion removal layer 12 of the first embodiment.

Example 3
According to the metal ion removing apparatus 1 of the third embodiment, as shown in FIG. 4, the metal ion removing layer 12 is composed of three layers 21 to 23 on the upper, middle, and downstream sides, and the upper and middle stream side layers 21. , 22 are formed by filling weak and strong acidic ion exchange resins as metal ion scavengers, respectively, and the downstream layer 23 is formed by filling strong acid ion exchange nonwoven fabrics as metal ion scavengers. ing.

  The packed bed of ion-exchange nonwoven fabric has a smaller bulk density than the packed bed of ion-exchange resin, and has a large contact area with the fuel per unit volume. For this reason, it is considered that the packed bed of ion exchange nonwoven fabric has a smaller total ion exchange capacity and facilitates the ion exchange reaction than the packed bed of ion exchange resin. For this reason, it is thought that the layer 23 which consists of a strong acid ion exchange nonwoven fabric has the capability to capture | acquire a metal ion although the amount which can capture | acquire a metal ion is smaller than the layer 22 which consists of a strong acid ion exchange resin.

  The weakly acidic ion exchange resin forming the layer 21 has, for example, a carboxyl group and is the same as the weakly acidic ion exchange resin forming the layer 13 of Example 1 and the layer 18 of Example 2. The strongly acidic ion exchange resin forming the layer 22 is, for example, one having a sulfonic acid group and the same as the strongly acidic ion exchange resin forming the layer 14 of Example 1 and the layer 19 of Example 2. . Further, the strongly acidic ion exchange nonwoven fabric forming the layer 23 has a molecular structure similar to that of the strongly acidic ion exchange resin forming the layer 22, for example, and has a sulfonic acid group as an ion exchange group.

  Thereby, for example, even when the upper and middle-stream layers 21 and 22 cannot sufficiently remove metal ions, as in the case where the flow rate of the fuel increases temporarily, the upper and middle-stream layers 21 and 22 The metal ions that have not been removed in step 1 can be captured and removed by the downstream layer 23.

  In this case, the downstream layer 23 has a sufficient function as long as the flow rate of the fuel is temporarily increased temporarily and the intermediate layers 21 and 22 cannot sufficiently remove metal ions. Therefore, since the amount of resin or nonwoven fabric to be filled in each of the layers 21 to 23 can be optimized according to the fuel flow rate at the normal time and the fuel flow rate at the time of rapid increase, the metal ion removing device 1 is more than necessary. The life can be extended without increasing the size.

[Modification]
According to the metal ion removing apparatus 1 of the embodiment, the metal ion removing layer 12 has two or three layers in the fuel flow direction. However, the metal ion removal layer 12 has four or more layers in the fuel flow direction. A metal ion removal layer 12 may be provided. Further, the flow direction of the fuel in the metal ion removal layer 12 is from the lower side to the upper side, but is not limited to such a mode, and is set, for example, from the one side to the other side in the horizontal direction. Alternatively, it may be set so as to go radially outward from the center. Furthermore, the aspect of the metal ion trapping material used for each layer is not limited to the examples.

DESCRIPTION OF SYMBOLS 1 Metal ion removal apparatus 12 Metal ion removal layer 13, 14, 17-19, 21-23 layer

Claims (4)

A metal ion removing layer formed of a metal ion scavenger capable of capturing metal ions;
In the metal ion removing apparatus for removing metal ions contained in the fuel by passing the fuel through the metal ion removing layer,
The metal ion removal layer is formed by stacking a plurality of layers of different metal ion trapping materials in the fuel flow direction,
The metal ion trapping material forming each layer has a larger number of types of metal ions that can be trapped in the downstream layer. The metal ion removing apparatus according to claim 1, wherein
Among the plurality of layers, at least one combination of the upstream layer and the downstream layer is an ion exchanger having an acidic ion exchange group in both layers as the metal ion scavenger,
The apparatus for removing metal ions according to claim 1, wherein the ion exchange groups in the downstream layer are more acidic than the ion exchange groups in the upstream layer. The metal ion removing apparatus according to claim 2,
The metal ion removing apparatus according to claim 1, wherein the ion exchanger of the downstream layer has a smaller total ion exchange capacity than the ion exchanger of the upstream layer. In the metal ion removal apparatus according to claim 2 or 3,
The said ion exchanger is filled as an ion exchange resin and an ion exchange nonwoven fabric, and forms a layer, The metal ion removal apparatus characterized by the above-mentioned.

Images