WO2015069170A1

WO2015069170A1 - Arrangement and method for electro-magnetic preseparation

Info

Publication number: WO2015069170A1
Application number: PCT/SE2014/051232
Authority: WO
Inventors: Jairo De Lima Souza
Original assignee: Scania CV AB
Current assignee: Scania CV AB
Priority date: 2013-11-06
Filing date: 2014-10-20
Publication date: 2015-05-14
Anticipated expiration: 2016-05-06
Also published as: SE1351309A1

Abstract

An arrangement and a method for separating ferromagnetic particles from an airflow flowing through an air system in a vehicle (1). The air system includes an air filter (5A, 5B). The arrangement comprises a pre-separator (9) disposed upstream of the air filter (5A, 5B), wherein the pre-separator (9) is configured so as to generate an electromagnetic field having an effect in the airflow in the air system such that ferromagnetic particles are captured from the airflow. The pre-separator (9) is further configured so as to be energized by means of an existing electrical system in the vehicle.

Description

Arrangement and method for electromagnetic pre-separation

Field of the invention

The present invention concerns an arrangement and a method for separating ferromagnetic particles from air flowing through an air system in a vehicle.

Background of the invention

A vehicle with an internal combustion engine is equipped with an air system for taking in air for the internal combustion engine. The air is drawn in through, for example, an air intake in the front or roof of the vehicle and on into the air intake of the internal combustion engine via pipes. The air that comes into the air system from the vehicle environment is frequently contaminated with particles such as dust, soot and other exhaust gas residues, and must be purified before it reaches the engine of the vehicle to prevent impurities from getting into the engine. An air filter, for example a paper filter, can be used to remove particles from the air. A chemical filter can also be used to remove gaseous impurities. The filters must be replaced at regular intervals because they become clogged and consequently spent. If any filter is clogged, the supply of air to the engine is decreased, which has a negative impact on combustion with increased fuel consumption as a result.

In a normal traffic situation, the proportion of iron oxide in the air accounts for roughly 20-30% of the total particle mass. In some environments, for example in a mine, the concentration of certain particles in the air is extremely high. The proportion of iron oxide in the air in a mine can range as high as 45-60% of the total particle mass in the air. In the case of an air filter that has the capacity to filter out 2.5 kg of particles, iron oxide can account for 1 .5 kg of that total. The quantity of particles is thus generally higher in a mining environment than in other environments, as are the quantities of certain particles. This means that the air filter must be replaced more frequently because it gets clogged more quickly. GB286387 describes the use of magnetized pipe screens to intercept metallic particles and thus prevent such particles from getting into a carburetor. The pipe screens are arranged after one or more particle filters. It is thus not possible for large metallic particles to be trapped by the pipe screens, since they are already adhering to the particle filters placed upstream.

The object of the invention is to provide an arrangement that prevents

ferromagnetic particles from burdening the air filter in an air system. Summary of the invention

According to a first aspect, the object is achieved at least partially by means of an arrangement for separating ferromagnetic particles from an airflow flowing through an air system in a vehicle. The air system includes an air filter. The arrangement includes a pre-separator disposed upstream of the air filter, wherein the pre- separator is configured so as to generate an electromagnetic field having an effect in the airflow in the air system such that ferromagnetic particles are captured from the airflow. The pre-separator is further configured so as to be energized by means of an existing electrical system in the vehicle. By means of the arrangement, ferromagnetic particles such as iron oxide can be captured before they reach the air filter. Fewer particles reach the air filter, whose service life is extended. A longer time can therefore elapse between replacements of the air filter cartridge in the air filter, thereby reducing costs. Fuel consumption can be kept low, since the air filter works better, which causes the engine to gain access to the proper amount of air so that the combustion is not degraded.

According to another aspect, the object is achieved at least partially by means of a method for separating ferromagnetic particles from an airflow flowing through an air system in a vehicle. The air system includes an air filter. The method comprises

- energizing a pre-separator disposed upstream of the air filter; - generating an electromagnetic field having an effect in the airflow in the air system such that ferromagnetic particles are captured from the airflow;

- interrupting the energization of the pre-separator, whereupon no electromagnetic field is generated to act on the airflow, whereupon at least a portion of the ferromagnetic particles captured by said electromagnetic field end up, under the effect of gravitation, in a collection unit.

According to the method, ferromagnetic particles can be captured by the electromagnetic field and are then collected when the electromagnetic field is shut off and the ferromagnetic particles fall, under the effect of gravitation, into a collection unit. The collection unit can subsequently be emptied of ferromagnetic particles.

According to a third aspect, the object is achieved at least partially by means of a computer program P associated with a control unit, wherein said computer program P includes program code that causes the control unit to perform any of the steps according to the method.

According to a fourth aspect, the object is achieved at least partially by means of a computer program product that includes a program code stored on a computer- readable medium so as to perform any of the method steps described herein.

Preferred embodiments are described in the independent claims and in the detailed description.

Brief description of the accompanying figures

The invention will now be described with reference to the accompanying figures, in which:

Figure 1 shows a vehicle comprising an air system for supplying an engine with air.

Figure 2 shows an example of an arrangement according to the invention disposed in connection with a pipe in the air system of Fig. 1 . Figure 3A shows an example of an air filter canister containing an air filter.

Figure 3B shows an additional example of an arrangement according to the invention disposed in connection with an air canister in the air system in Fig. 1 . Figure 3C shows yet another example of an arrangement according to the invention disposed in connection with an air canister in the air system in Fig. 1 . Figure 4A shows an example of a pre-separator according to one embodiment of the invention.

Figure 4B shows the pre-separator in Fig. 4A when disposed inside an air pipe. Figure 4C shows an additional example of a pre-separator comprising a plurality of pre-separators of the kind illustrated in Fig. 4A and Fig. 4B according to one embodiment of the invention.

Figure 5 shows a flow chart for the method according to one embodiment of the invention. Detailed description of preferred embodiments of the invention

Figure 1 shows a vehicle 1 with a cab 2 and an air system for supplying an internal combustion engine 8 in the vehicle 1 with air. The air system here includes two distinct air intakes 3A, 3B, one air intake 3A in the front of the vehicle and one air intake 3B disposed in the roof of the vehicle. The placement of the air intakes 3A, 3B can, however, be different than that shown; for example, an air intake can be disposed in the side of the vehicle 1 . The air system can also comprise only one air intake. The vehicle 1 is depicted here as a goods vehicle 1 , but it can instead be a car, a tractor or another industrial vehicle. Air from the vehicle environment is conducted from the air intakes 3A, 3B through the pipes 4A, 4B for further routing to one or more air filters 5A, 5B. The vehicle 1 in Fig. 1 is equipped with two air filters 5A, 5B, one air filter 5A for an airflow that is conducted from the air intake 3A at the front of the vehicle via pipe 4A to the air filter 5A, and an additional air filter 5B for an additional airflow that is conducted from air intake 3B in the roof of the vehicle via pipe 4B to the air filter 5B. The air filters 5A, 5B are each housed in a respective air filter canister 6A, 6B, for example in the form of replaceable filter cartridges. The air filters 5A, 5B can, for example, consist of paper filters that capture particles exceeding a given size. From the air filters 5A, 5B the filtered air is then conducted through pipe 7A and on through a common pipe 7B before reaching the engine 8. The direction of the airflow is illustrated by means of the arrows in the pipes 4A, 4B, 7A, 7B. The air system is shown here only as an example, and can be varied in different ways.

One or more arrangements for separating ferromagnetic particles from the airflow or airflows can be arranged in connection with the air system shown in Fig. 1 . A number of different examples of such arrangements will now be described with reference to Figures 2-3C. With regard to all the embodiments in general, the arrangement thus comprises a pre-separator 9 disposed upstream of the air filter 5A, 5B, hence between an air intake 3A, 3B and the air filter 5A, 5B. The pre- separator 9 is configured so as to generate an electromagnetic field that causes the airflow in the air system to capture ferromagnetic particles from the airflow. The pre-separator 9 is further configured so as to be energized by an existing electrical system in the vehicle 1 . The pre-separator 9 can, for example, be designed as a layer, a coating, one or more coils, one or more windings, one or more solenoids, or a combination of two or more of these embodiments. The pre- separator 9 also comprises a form of electromagnet. An electromagnet is produced, for example, from a wire of electrically conductive material that is wound helically. When current is conducted by means of these helical wires, a magnetic field is generated that captures ferromagnetic particles. The helical wire is made from one or more ferromagnetic materials, such as iron, cobalt or nickel.

According to one embodiment, the pre-separator 9 is thus disposed in connection with a collection unit 1 3, 6B for the ferromagnetic particles, so that at least a portion of the ferromagnetic particles that are captured by the electromagnetic field end up, under the effect of gravitation, in the collection unit 13, 6B when the pre-separator 9 is not energized and thus is not generating an electromagnetic field. According to one embodiment, the collection unit 13 can be removed from the air system so that the collection unit 1 3 can be emptied. Figure 2 shows a section of the pipe 4A that conducts an airflow from the air intake 3A to the air filter 6A (Fig. 1 ), here divided into two pipes. A pre-separator 9 is disposed in the respective pipe 4A of the air system in the form of a felt 27 having two layers 24 and a pair 23 of windings (Fig. 4C), plus a coil 25 on the inner face 14 of pipes 4A. The arrangement here includes the control unit 10 that is connected to the existing electrical system in the vehicle 1 . As illustrated in Fig. 2, the control unit 10 is thus connected to the pre-separator 9, i.e. the layers 24 and the coils 25, in order to energize the pre-separator 9. The pre-separator 9 is disposed inside the pipe 4A above or at least partially above the collection unit 13. When the pre-separator 9 is energized, an electromagnetic field is thus generated in the airflow in the pipe 4A, i.e. from one inner face 14 of pipe 4A to an opposite inner face 14 of the pipe 4A. The ferromagnetic particles drop down into the collection unit 1 3 as soon as the electromagnetic field ceases. The collection unit 13 can, for example, be combined with an existing bleeder valve in the pipe 4A. In this way, the ferromagnetic particles can be collected by means of the bleed valve downwardly in the collection unit 1 3.

According to one embodiment, the arrangement thus comprises a control unit 10 that is connected to the existing electrical system (not shown) in the vehicle 1 . The control unit 10 comprises a processor unit 1 1 plus a memory unit 12. The processor unit 1 1 can, for example, comprise a CPU (Central Processing Unit). The memory unit 12 can contain one or more memories, for example a nonvolatile memory such as, for example, a flash drive or F-RAM. The memory unit 12 can have a program P stored, which computer program P contains program code that causes the control unit 10 to perform the method that will be described hereinafter. The control unit 10 is further connected to the pre-separator 9 in order to energize the pre-separator and is configured so as to regulate the energization of the pre-separator 9 according to rules for the use of the pre-separator 9. The rules for the use of the pre-separator 9 are based, according to one embodiment, on at least one of: the driving status of the vehicle, the engine capacity of the vehicle, the topography of the road and the energy demand of the vehicle. The energy demand of the vehicle under different loads can be described by means of a chart showing the engine capacity under various conditions, for example different loads and velocities. This chart is normally accessible in the vehicle 1 and accessible by the control unit 10. The driving status of the vehicle can, for example, include that the vehicle is traveling at a given speed, that the vehicle engine 8 is not running or that the vehicle engine 8 is running. The driving status of the vehicle can be determined by receiving data from other units in the vehicle 1 . The rules include, for example, interrupting the energization of the pre- separator 9 when the vehicle engine 8 is turned off. In the event that the vehicle engine 8 is running, energy is generated so that the pre-separator 9 can be energized. In the event that the vehicle 1 has a heavy energy demand for any period of time, the pre-separator 9 can be activated for that period, so that the vehicle engine 8 receives all the available energy. This can occur when driving on an uphill slope, for example. By knowing the topography of the road in advance, the control unit 10 can deactivate or activate the pre-separator 9. The future topography of the road can be made known by using cartographic data, and by knowing the position and future route of the vehicle on the map. For example, data from a cartographic data unit 19 and a positioning unit 20 can be sent to the control unit 10, which derives information concerning the topography of the future route on the basis thereof. When the vehicle 1 comes to an uphill slope, the control unit 10 can then regulate the energy supply to the pre-separator 9, for example, throttling the energy supply completely. During travel on a downhill slope, the control unit 10 can thus, in similar fashion, determine where the uphill slope begins and ends, and can deactivate the pre-separator 9, since the airflow to the engine 8 is lower when the vehicle 1 is being engine-braked. Data concerning the velocity of the vehicle can be obtained from a speedometer. If the velocity is high, it means that the vehicle 1 has a heavy energy demand, and the control unit 9 can then deactivate the pre-separator 9 so that the vehicle 1 can receive all the energy that is available. If the engine 8 of the vehicle is idling, then the airflow to the engine 8 is low. The pre-separator 9 can then be deactivated to save on fuel. Data can be exchanged among the various units in the vehicle 1 by means of an internal network comprising, for example, a CAN (Controller Area Network) bus that uses a message-based protocol. Other types of buses and protocols are also conceivable, however, for example a LIN (Local Interconnect Network). According to one embodiment, the control unit 10 includes an energy supply part 16, which is configured so as to supply energy to the pre-separator 9 when the control unit 10 issues instructions to the energy supply part 16 to supply energy. The energy supply part 16 is, in that case, connected to the pre-separator 9 by one or more lines.

Figure 3A shows the air filter canister 6A, 6B in greater detail. The air flows in through the pipe 4A, 4B, in through the air filter 5A, 5B, and out through the middle of the air filter 5A, 5B. A collection unit 13 in the form of a removable cover on the air filter canister 6A, 6B for enabling replacement of the air filter cartridge is also shown.

Figures 3B and 3C show the air filter canister 6A, 6B in cross-section in an upright position (6A), and in a horizontal position (6B). The direction of the flow of air through the pipe 4A, 4B and the air filter 5A, 5B is indicated by arrows. The pre- separator 9 is shown here in the form of a helical wire 25, which is arranged along the inside face 15A, 15B of the air filter canister 6A, 6B. The pre-separator 9 is also disposed in the air filter canister 6A, 6B that surrounds the air filter 5A, 5B. More specifically, the pre-separator 9 is thus disposed between the air filter 5A, 5B and the inner face 15A, 15B of the air filter canister. The pre-separator 9 is depicted here as the helical wire 25, but it can instead be a coating or a layer 24 on the inner face 15A, 15B. Thus, as shown in the figures, the pre-separator 9, i.e. the helical wire 25, is electrically connected to the control unit 10 for energizing the pre-separator 9. The pre-separator 9 can be connected to the energy supply part 16 in the control unit 10, which is configured so as to supply energy to the pre-separator 9 when the control unit 10 issues instructions to the energy supply part 16 to supply energy. The airflow thus enters the filter canister 6A, 6B through the pipe 4A, 4B, which empties into the filter canister 6A, 6B. Once the pre- separator 9 is energized, it then generates an electromagnetic field in the space between the air filter 5A, 5B and the inner face 1 5A, 15B of the air filter canister 6A, 6B. The field captures ferromagnetic particles from the airflow before the airflow reaches the air filter 5A, 5B and draws them to the inner face 15A, 15B of the air filter canister 6A, 6B. The airflow continues on through the air filter 5A, 5B, which captures additional particles before the filtered airflow passes on out of the air filter canister 5A, 5B.

When the pre-separator 9 is deactivated, for example when the vehicle engine 8 is turned off and the pre-separator 9 is no longer being energized, the

ferromagnetic particles that have been captured thus drop downward under the effect of gravitation. Figure 3B shows an upright air filter canister 6A, which entails that the ferromagnetic particles will drop into the collection unit 13, which is here the lower part 1 3 of the filter canister. Said lower part 13 can be removed from the filter canister 6A and can then be emptied of ferromagnetic particles and put back again. The lower part 13 is here disposed on the air filter 5A via an intermediate part 17. The air filter 5A can be in the form of a replaceable air filter cartridge. In Fig. 3C, which shows a horizontal air filter canister 6B, deactivation of the pre- separator 9 thus entails that at least some of the ferromagnetic particles will drop onto the inner face 15B of the filter canister. Opening up the filter canister 6B, for example by opening the lower part 18 of the air filter canister 6B, and taking out the air filter 5B makes it possible to access the collected ferromagnetic particles and gather them. The filter canister 6B here constitutes the collection unit. It can be vacuumed out or blown out, for example.

As explained above, the pre-separator 9 can comprise a helical wire of electrically conductive material. The helical wire, also called a solenoid, can be insulated and wrapped around a core of metallic material to form a coil, which strengthens the magnetic field generated by the helical wire. The term "coil" thus signifies here an insulated, helical wire or solenoid wound around a core of metallic material. Figure 4A shows an additional embodiment of a pre-separator 9, wherein the pre- separator 9 includes at least two coils 22A, 22B, respectively constituting a north pole and a south pole, in a sort of horseshoe magnet. The two coils 22A, 22B having, respectively, a north pole and a south pole constitute a coil pair 23. The helical wires of the respective coils 22A, 22B are connected to each other and to a control unit 10 for energization. The two coils 22A, 22B can be disposed on the inner face 14 of pipe 4A (Fig. 2) or on the inner face 15A, 15B of the air filter canister 6A, 6B (Figs. 3B, 3C). The coils 22A, 22B can be fastened to a backing piece 21 so that they can more easily be fastened to any inner face 14, 15A, 1 5B. Figure 4B shows how the coils 22A, 22B are arranged on the inner face 14 of air pipe 4A (Fig. 2) so that the plane of the direction of the windings in the coils 22A, 22B is mainly vertical to the direction of the airflow in air pipe 4A. The direction of the airflow is indicated by arrows in the air pipe 4A. When the pre-separator 9 is energized, an electromagnetic field 26 is generated vertically in relation to the airflow in air pipe 4A.

Figure 4C illustrates an additional embodiment of a the pre-separator 9. The pre- separator 9 here includes a plurality of coil pairs 23, which are disposed between two flexible layers 24 and form a kind of felt 27. According to another

embodiment, the pre-separator 9 comprises only one flexible layer 24 on which the coil pairs 23 are disposed. The layer 24 is flexible, so that it can be bent and thus fitted into an air pipe 4A or air canister 6A, 6B without being broken. A layer 24 can, for example, be fashioned of plastic film, or consist of a plate of plastic. Figure 4C depicts 96 coils 22A, 22B, which together constitute 48 coil pairs 23. The coil pairs 23 are connected to one other, for example in series, and are energized by means of the control unit 10. In this embodiment, the pre-separator 9 can be disposed on the inner face 14 of pipe 4A, as illustrated in Fig. 2, or on the inner face 1 5A, 1 5B of the air canister 6A, 6B (Figs. 3B-3C). The pre- separator 9 can be fastened to any inner face 14, 15A, 15B with glue, or by being securely riveted to any inner face 14, 15A, 15B by means of rivets.

According to one embodiment, the arrangement also wholly or partially comprises the air pipe 4A or the air filter canister 6A, 6B. Illustrated in Fig. 5 is a flow chart for a method for separating ferromagnetic particles from an airflow flowing through the air system in the vehicle 1 , as described in connection with Fig. 1 . The method will now be described with reference to the flow chart. The method comprises energizing the pre-separator 9 disposed upstream of the air filter 5A, 5B (A1 ) and generating an electromagnetic field having an effect in the airflow in the air system such that ferromagnetic particles are captured from the airflow (A2). The method then comprises interrupting the energization of the pre-separator 9 so that no electromagnetic field having an effect on the airflow is generated. At least a portion of the ferromagnetic particles captured from the electromagnetic field end up, under the effect of gravitation, in the collection unit 13, 6B. The interruption of the energization can involve, for example, interrupting the energization of the pre- separator 9 when the vehicle engine 8 is turned off.

According to one embodiment, the method includes respectively energizing and interrupting the energization of the pre-separator 9 according to rules for the use of the pre-separator 9. The rules for the use of the pre-separator 9 are based on at least one of: the driving status of the vehicle, the engine capacity of the vehicle, the topography of the road and the energy demand of the vehicle.

The preceding invention is not limited to the embodiments described above.

Various alternatives, modifications and equivalents can be used. The

aforementioned embodiments of the invention thus do not limit the scope of the invention, which is defined in the accompanying claims.

Claims

1 . An arrangement for separating ferromagnetic particles from an airflow flowing through an air system in a vehicle (1 ), wherein said air system includes an air filter (5A, 5B), characterized in that said arrangement comprises a pre- separator (9) disposed upstream of said air filter (5A, 5B), wherein said pre- separator (9) is configured so as to generate an electromagnetic field having an effect in the airflow in said air system such that ferromagnetic particles are captured from said airflow, [wherein] said pre-separator (9) is further configured so as to be energized by means of an existing electrical system in said vehicle (1 ).

2. The arrangement according to claim 1 , comprising a control unit (10) that is connected to the existing electrical system in said vehicle (1 ), [wherein] said control unit (10) is further connected to said pre-separator (9) in order to energize said pre-separator and configured so as to regulate the energization of said pre-separator (9) according to rules for the use of said pre-separator (9).

3. The arrangement according to claim 2, wherein the rules for the use of said pre-separator (9) are based on at least one of: the driving status of the vehicle, the engine capacity of the vehicle, the topography of the road and the energy demand of the vehicle.

4. The arrangement according to claim 3, wherein said rules include interrupting the energization of said pre-separator (9) when the vehicle engine (8) is turned off.

5. The arrangement according to any of the preceding claims, wherein said pre-separator (9) is disposed in connection with a collection unit (13, 6B) for said ferromagnetic particles, so that at least a portion of the ferromagnetic particles captured by said electromagnetic field end up in said collection unit (1 3, 6B) under the effect of gravitation when said pre-separator (9) is not being energized and is thus not generating an electromagnetic field.

6. The arrangement according to claim 5, wherein said collection unit

(1 1 ) can be removed from the air system so that the collection unit (1 1 ) can be emptied.

7. The arrangement according to any of the preceding claims, wherein said pre-separator (9) comprises at least two coils (22A, 22B).

8. The arrangement according to claim 7, wherein said pre-separator (9) comprises at least one flexible layer (24) on which said coils (22A, 22B) are disposed.

9. The arrangement according to any of the preceding claims, wherein said pre-separator (9) is disposed in a pipe (7A) in said air system.

10. The arrangement according to any of the preceding claims, wherein said pre-separator (9) is disposed in an air filter canister (6A, 6B) that surrounds said air filter (5A, 5B).

1 1 . A method for separating ferromagnetic particles from an airflow flowing through an air system in a vehicle (1 ), wherein said air system comprises an air filter (5A, 5B), which method comprises

- energizing a pre-separator (9) disposed upstream of said air filter (5A, 5B);

- generating an electromagnetic field having an effect in the airflow in the air system such that ferromagnetic particles are captured from said airflow;

- interrupting the energization of said pre-separator (9), whereupon no

electromagnetic field having an effect in said airflow is generated, wherein at least a portion of the ferromagnetic particles captured by said electromagnetic field end up, under the effect of gravitation, in a collection unit (13, 6B).

12. The method according to claim 1 1 , which includes respectively energizing and interrupting the energization of said pre-separator (9) according to rules for the use of said pre-separator (9).

13. The method according to claim 1 1 , wherein said rules for the use of said pre-separator (9) are based on at least one of: the driving status of the vehicle, the engine capacity of the vehicle, the topography of the road and the energy demand of the vehicle.

14. The method according to any of claims 9 to 1 1 , wherein interrupting the energy supply includes includes interrupting the energization of said pre- separator (9) when the vehicle engine (8) is turned off.

15. A computer program (P) associated with a control unit (10), wherein said computer program (P) includes program code that causes said control unit (10) to perform any of the steps according to claims 1 1 to 14.

16. A computer program product comprising a program code stored on a computer-readable medium for performing the method steps according to any of claims 1 1 to 14.