JPH09309329A - Air purifying device for automobile and regenerating method of absorbent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air purifying device for an automobile capable of regenerating an absorbent at proper timing and a regenerating method of the absorbent. SOLUTION: Removal capacity of an activated carbon filter 32 is monitored by detecting a pollution level of air before passing the activated carbon filter 32 by an upstream odor sensor 46, detecting a pollution level of air after passing it by a downstream odor sensor 48 and comparing the pollution levels before and after passing the activated carbon filter 32 with each other. Hereby, desorption of a material to be absorbed is started at the time when absorbing capacity is lowered and a difference of the pollution levels before and after the activated carbon filter 32 becomes small. Consequently, it is possible to start regenerating motion at the time when the absorbing capacity of the activated carbon filter 32 is actually lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air purifying apparatus for purifying air inside a vehicle by regenerating the adsorbent and a method for regenerating the adsorbent.

[0002]

2. Description of the Related Art An air purifying apparatus for an automobile has been put into practical use in which activated carbon or the like is housed in a cartridge and air in the vehicle is pressure-fed to the cartridge to purify the air. Here, in an automobile air purifying apparatus, a disposable type adsorbent such as activated carbon has been used. For this reason,
It is uneconomical because the adsorbent needs to be replaced frequently, and if the replacement time is delayed, the air cannot be properly purified.

[0003]

The present applicant has filed a patent application for a purifying device for purifying the air inside a vehicle by adsorbing NO _X discharged from other vehicles using an adsorbent composed of activated carbon. Proposed in No. 7-350606. In the present invention, the activated carbon is heated to absorb the adsorbed NO _x.
Is desorbed and the activated carbon can be reused.

[0004] Here, there is a problem in which timing the activated carbon is regenerated. The present inventor has studied a method of integrating the operating time of the purifying device and performing a regenerating operation when the integrated value reaches a predetermined value. However, the purification device for a motor vehicle, unlike the degree of adsorption of the NO _X into the activated carbon by the use environment, for example, running a vehicle mainly running high industrial zone of degree of contamination of the atmosphere, a low degree of contamination of air suburban and the drive to, for nO _X adsorption amount of activated carbon, even the same operating time are different, the integration time is not be a indicator of the start of reproduction. Furthermore, the characteristics of activated carbon change with repeated regeneration. That is, the NO _x adsorption performance gradually decreases each time regeneration is performed, and therefore the regeneration start interval cannot be made constant. A method of shortening the interval until the next regeneration can be considered in accordance with the deterioration of the adsorption performance at each regeneration, but since this reduction rate changes due to various factors, it is only possible to shorten the interval uniquely. Then, it turned out that we could not deal with it.

Further, when reproducing, there has been a problem in which timing the reproduction is completed. That is, since the characteristics of the activated carbon change each time the regeneration is repeated, if the heating time is kept constant, the activated carbon which has been completely regenerated will continue to be heated, or conversely, the regeneration will not be completed. It was predicted that heating would be cut off for the activated carbon.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an automobile air purification apparatus and an adsorbent regeneration method capable of regenerating the adsorbent at an appropriate timing. To provide.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to regenerate an adsorbent of an air purifying apparatus for an automobile capable of completing the regeneration of the adsorbent at an appropriate timing. To provide a method.

[0008]

In order to achieve the above-mentioned object, an automobile air purification apparatus for purifying air according to claim 1 is an adsorbent for air purification and air before passing through the adsorbent. Upstream detecting means for detecting the degree of pollution of the adsorbent, downstream detecting means for detecting the degree of pollution of the air after passing through the adsorbent, and before and after passage of the adsorbent detected by the upstream detecting means and the downstream detecting means. Decontamination means for starting the desorption of the substance to be adsorbed from the adsorbent based on the comparison result after comparing the degree of contamination.
Is a technical feature.

According to a second aspect of the present invention, in the first aspect, the desorption means compares the contamination degree before and after the adsorbent has passed, and when the difference or ratio of the contamination degrees is smaller than a predetermined value, The technical feature is to start desorption of the substance to be adsorbed from the adsorbent.

A third aspect of the present invention is characterized in that, in the first or second aspect, the upstream detecting means and the downstream detecting means share one sensor to detect the degree of contamination.

According to a fourth aspect of the present invention, there is provided a method for regenerating an adsorbent of an air purifying apparatus for an automobile, which purifies air by using the adsorbent for air purification while regenerating the adsorbent. The step of detecting the degree of pollution, the step of detecting the degree of pollution of the air after passing through the adsorbent, and the degree of pollution of the air before and after passing through the adsorbent are compared to obtain a difference or ratio of the degree of pollution. Is to be smaller than a predetermined value, reproduction is started.

According to a fifth aspect of the present invention, there is provided a method of regenerating an adsorbent in an air purifying apparatus for an automobile, which purifies air by regenerating the adsorbent for air purification.
Detecting the degree of air pollution before passing through the adsorbent; detecting the degree of air pollution after passing through the adsorbent during regeneration of the adsorbent; and before and after passing through the adsorbent. And the step of terminating the regeneration of the adsorbent based on the comparison result.

According to a sixth aspect of the present invention, in the step of terminating the regeneration of the adsorbent according to the fifth aspect, the pollution degree of air before and after passing through the adsorbent is compared, and the difference or ratio of the pollution degrees is a predetermined value. The technical feature is that the regeneration of the adsorbent is terminated when it becomes larger than the above.

[0014]

According to the first aspect of the present invention, the upstream detecting means detects the pollution degree of air before passing through the adsorbent, and the downstream detecting means detects the pollution degree of air after passing through the adsorbent. Then, the desorption unit compares the contamination levels before and after the adsorbent detected by the upstream detection unit and the downstream detection unit, and starts desorption of the adsorbed substance based on the comparison result.

In the second aspect of the present invention, the desorption means compares the degree of contamination of the adsorbent detected by the upstream detection means and the downstream detection means before and after the passage, and the adsorbing ability of the adsorbent decreases. Desorption of the adsorbed substance is started when the difference or ratio in the degree of contamination before and after the adsorbent becomes small. Therefore, the regeneration of the adsorbent can be started when the adsorption capacity of the adsorbent actually decreases.

Here, the sensors for measuring the degree of contamination have different output characteristics, and if two sensors measure the same degree of contamination, different values will be detected. Therefore,
When separate sensors are used for the upstream detection means and the downstream detection means, it is difficult to perform accurate measurement. On the other hand, according to the third aspect of the present invention, the upstream detecting means and the downstream detecting means share the same sensor to detect the degree of contamination, so that the degree of contamination can be accurately detected.

In the invention of claim 4, the degree of contamination of air before and after passing through the adsorbent is compared, the adsorption capacity of the adsorbent is reduced, and the difference or ratio of the degree of contamination before and after the adsorbent is small. When this happens, desorption of the substance to be adsorbed is started. Therefore, the regeneration of the adsorbent can be started when the adsorption capacity of the adsorbent actually decreases.

According to the fifth aspect of the invention, when the adsorbent is regenerated, the degree of contamination of air before and after passing through the adsorbent is compared, and regeneration of the adsorbent is completed based on the comparison result. Therefore, the regeneration of the adsorbent can be completed when the adsorption capacity of the adsorbent is actually recovered.

According to the sixth aspect of the present invention, at the time of regeneration of the adsorbent, the degree of contamination of air before and after passing through the adsorbent is compared, the adsorbing ability of the adsorbent is recovered, and the contamination before and after the adsorbent is recovered. When the difference or ratio in degrees becomes large, desorption of the adsorbed substance is completed. Therefore, the regeneration of the adsorbent can be completed when the adsorption capacity of the adsorbent is actually recovered.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments embodying the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an automobile air purification device 10 according to a first embodiment of the present invention. The air purification device 10 is housed in a trunk room (not shown) of a vehicle, and an intake port 22 and an outlet port 24 formed in an upper portion of the housing 20 are arranged so as to open to the inside of the vehicle. That is, the air in the vehicle taken in through the suction port 22 is purified by the activated carbon filter 32 and the CO oxidation filter 34, and is discharged into the vehicle through the air outlet 24. Below the outlet 24, an exhaust port 26 is formed for exhausting NO _{x and the} like desorbed from the activated carbon filter 32 to the trunk room side when the activated carbon filter 32 is regenerated. That is, the trunk room is formed so that the air inside the vehicle escapes to the outside of the vehicle and a negative pressure is applied to perform ventilation.Therefore, by connecting the exhaust port to the trunk room, the exhaust air is discharged to the outside of the vehicle through the trunk room. It is configured to discharge.

In the air purification device 10, the air purified by the activated carbon filter 32 and the CO oxidation filter 34 is discharged from the outlet 24 via the exhaust switching hole 28 during the purification of air. On the other hand, during the regeneration of the activated carbon filter 32, the exhaust switching hole 28 is closed by the exhaust switching valve 30, so that the N separated from the activated carbon filter 32 is removed.
O _{X and the} like are discharged from the exhaust port 26 to the trunk room.

A fan 40 for feeding air under pressure and a motor 42 for rotating the fan 40 are disposed below the suction port 22. On the other hand, a metal halide lamp 36 that irradiates the activated carbon filter 32 with ultraviolet rays is disposed near the activated carbon filter 32. A temperature sensor 38 is attached to the activated carbon filter 32. Then, on the upstream side of the activated carbon filter 32, CO
CO sensor 44 for detecting the concentration, smell of cigarettes,
An upstream odor sensor 46 for detecting NO _{X and the} like is provided, and a downstream odor sensor 48 is provided downstream of the activated carbon filter 32. That is, the upstream odor sensor 46 detects the odor of cigarettes in the air before passing the activated carbon filter 32, and the downstream odor sensor 48 detects the odor after passing the activated carbon filter 32. As the upstream odor sensor 46 and the downstream odor sensor 48, for example, an n-type semiconductor gas sensor that detects the oxidation reaction rate of the gas adsorbed on the surface of the porous semiconductor can be used.

The motor 42 has a PWM (Pulse Width Modulation) from a motor control circuit 52.
n) The speed is controlled by the signal. Further, the metal halide lamp 36 is adapted so that a voltage is applied by the ballast 50 so that the metal halide lamp 36 is extinguished / lit and the illuminance is adjusted. The motor control circuit 52 and the ballast 50
Are configured to be controlled by the control device 60. The control device 60 uses the signals from the upstream odor sensor 46 and the downstream odor sensor 48 to determine the rotation speed of the motor 42,
Illuminance of the metal halide lamp 36 and the exhaust switching valve 3
Control 0.

The adsorption filter 32 includes a metal filter, activated carbon for adsorbing odorous components such as NO _X , and a photocatalyst made of TiO ₂ which oxidizes and decomposes aldehydes, ammonia, etc. which are difficult to adsorb with activated carbon. Is loaded with an adsorbent. The photocatalyst is activated by ultraviolet rays from the metal halide lamp 36, and oxidizes and decomposes aldehydes, ammonia, etc., which are the main components of the tobacco odor that are difficult to be adsorbed by the activated carbon filter 32, by a photocatalytic reaction, and finally water. , Carbon dioxide, nitric acid. In addition, this photocatalyst is NO which is difficult to be adsorbed by activated carbon.
And also it has the action to oxidize to easily NO _X adsorbed in the activated carbon.

The filter is formed by stacking members obtained by folding stainless thin plates in a honeycomb shape. Here, by using a filter obtained by folding a thin plate in a honeycomb shape as a filter for supporting the adsorbent, it is possible to reduce the pressure loss, increase the surface area of the adsorbent, and efficiently irradiate ultraviolet rays. I have to.

The photocatalyst for the oxidation and decomposition in substances more like HNO ₃ and NO _X adsorbed in the adsorbent, NO _X is suppressed the rate at which accumulated in the activated carbon by supporting a photocatalyst. In addition to this, since various organic substances (odorous components) other than NO _x that actually exist inside and outside the vehicle are oxidized and decomposed, the rate at which the organic substances accumulate can be suppressed,
Organic substances once adsorbed by the adsorbent can also be oxidized and decomposed.

[0027] At the photocatalyst even while degradation such as NO _X, continues to be adsorbed to NO _X such as activated carbon decreases the adsorption performance. Therefore, in the air purification device 10 of the first embodiment, the surface temperature of the adsorption filter 32 is increased by increasing the intensity of the ultraviolet light emitted from the metal halide lamp 36,
Desorb the adsorbed material to regenerate the adsorbent,
By increasing the activity of the photocatalyst, oxidation by the photocatalyst
Further decomposed to promote, and allowed removing odor components of the NO _X or the like which is adsorbed on activated carbon.

On the other hand, the CO oxidation filter 34 comprises a carrier such as activated carbon fiber or alumina carrying a noble metal oxidation catalyst such as Pd for oxidizing CO into CO ₂ .

Next, the operation of the air purifying device 10 will be described with reference to the flow charts of FIGS. First, the control device 60 determines whether or not a start-up switch (not shown) provided on the instrument panel on the driver side has been operated (S12). Here, when the start switch is operated (Yes in S12), the upstream odor sensor 46 measures the degree of pollution of the air before passing through the activated carbon filter 32 (S14), and then the activated carbon filter 32 is passed. The degree of pollution of the subsequent air is measured by the downstream odor sensor 48 (S16).

After that, the process proceeds to the reproducing process (S30). FIG. 3 shows a subroutine of the reproducing process.
This will be described with reference to FIG. First, the control device 60 determines whether internal air circulation is set or external air introduction is set in an air control device (not shown) of the vehicle in which the air purification device 10 is mounted. That is,
Prior to determining the odor removal capability of the activated carbon filter 32, it is necessary when the outside air introduction that introduces air from the outside is set and when the inside air circulation is set and the limited air in the vehicle is circulated. Since the removal capacities are different, it is first determined in step 32 whether or not the inside air is circulated.

Here, when the inside air circulation is set (Yes in S32), the pollution degree of the air before passing through the activated carbon filter 32 measured in the above step 14,
It is determined whether or not the difference between the pollution degree of the air after passing through the activated carbon filter 32 measured in step 16 and the second value set in advance is larger (S34). This difference in pollution degree will be described with reference to FIG. In FIG.
The output voltage of the upstream odor sensor 46 is shown in the curve A, the output voltage of the downstream odor sensor 48 is shown in the curve B, and the horizontal axis represents elapsed time. For example, at time t1, the removal capability of the activated carbon filter 32 remains sufficient to strongly remove the odor, so the difference between before and after passage is large. On the other hand, NO _{X and the} like are adsorbed to the activated carbon filter 32 over time,
When the adsorption rate decreases due to saturation, the difference between before and after passing decreases. As described above, in the first embodiment, the removal capability of the activated carbon filter 32, that is, the necessity of regeneration is determined based on the difference before and after passage.

At time t1, the removal capacity of the activated carbon filter 32 remains sufficient and the odor is strongly removed, so that the difference between before and after passage becomes larger than the second value (S34: No), it is determined that the reproduction is not necessary, the subroutine is terminated, and the process proceeds to step 70 shown in FIG.
Start the air purification process. In addition, when the outside air introduction is set, the determination in step 32 is No, the process proceeds to step 36, and the difference between the contamination degree of air before and after passing through the activated carbon filter 32 is set to a preset value. It is determined whether or not it is larger than the value of 1 (a value larger than the second value is set). Here, when the value is larger than the first value (Yes in S36), it is determined that the reproduction is not necessary, the subroutine is terminated, and step 70 shown in FIG.
Go to and start the air purification process.

Prior to the description of the purification process in step 70, the removal rate of the activated carbon filter 32 will be described with reference to FIG. In the graph of FIG. 6, the vertical axis represents the removal rate of the activated carbon filter 32, and the horizontal axis represents the air flow rate. The pattern (a) represents the removal rate of the new activated carbon filter 32, and the patterns (b) and (c). ), (D), and (e) show the activated carbon filter 32 in which the removal rate is gradually decreased by repeating the regeneration. As shown in the graph, the activated carbon filter 32 shows a constant removal rate when the amount of air blown is below a certain level (for example, 70% removal up to 0 to 300 L / min for new products shown in pattern (a)). The air flow rate is a certain amount (300 L for a new product)
/ Min), it gradually decreases. Here, by repeating the regeneration, the amount of air blown showing a constant removal rate decreases and the constant removal rate decreases (for example,
The activated carbon filter 32 shown in the pattern (e) in which the regeneration is repeated most times has a constant removal rate (30%) up to 160 L / min).

That is, the characteristics of the activated carbon filter 32 gradually deteriorate. Here, the amount of contamination (odor) removed X is a value obtained by multiplying the removal rate η by the air flow rate Q (X = η × Q), but as described above, when the removal rate becomes a certain value or more, It is inversely proportional to the air volume. Therefore, if the maximum air flow rate of the fan 40 is, for example, 600 L / min, the removal rate η will decrease when the air having the maximum air flow rate is passed through the activated carbon filter 32, and therefore the removal amount X of the pollution (odor) is not necessarily the same. It does not reach the maximum. Therefore, in the first embodiment, the characteristics of the patterns (a) to (e) of the activated carbon filter 32 shown in FIG. 6 are shown in FIG.
As shown in FIG. 3, the map is held as a map, and the optimum air volume that maximizes the removal amount X is obtained from this map. That is, in the first embodiment, the air is efficiently purified by selecting the optimum air flow rate according to the change in the characteristics of the activated carbon filter 32.

Now, the purification processing subroutine of step 70 will be described with reference to FIG. First, the control device 60 divides the pollution degree of the air before passing through the activated carbon filter 32, measured in step 14 described above with reference to FIG. 2, by the pollution degree after passing, measured in step 16. Thus, the removal rate η by the activated carbon filter 32 is calculated (S71). Then, it is specified which of the patterns (a) to (e) in the map shown in FIG. 7 the characteristic of the activated carbon filter 32 belongs to, from the amount of air blown when the removal rate is measured (S72). For example, if the blowing rate is 200 L / min when the removal rate is 60%, it is determined that the activated carbon filter 32 has the pattern (b) characteristics. Further, if the blowing rate is 350 L / min at the same removal rate of 60%, it is determined that the activated carbon filter 32 has the characteristics of pattern (a).

Subsequently, whether or not the degree of pollution is high is determined by checking the present degree of pollution (measured in step 14 by the activated carbon filter 3).
The judgment is made by comparing the air pollution degree before passing 2) with a predetermined value (S74). Here, when the degree of pollution is higher than a predetermined value (Yes in S74), the air flow rate (optimal air flow rate) Q that maximizes the amount of pollution (odor) removed is shown in FIG.
(S76). Here, assuming that the ability of the activated carbon filter 32 is the pattern (a),
It is assumed that the optimum air flow rate is 500 L / min. After that, a command value is set in the motor control device 52 so that the air flow rate becomes 500 L / min (S78),
Based on the command value, the motor control device 52 PWM-controls the motor 42 to obtain a target value of 500 L /
The air is blown for min (S86) to achieve the maximum removal amount. Then, the activated carbon filter 32 is irradiated with relatively weak ultraviolet rays from the metal halide lamp 36 (S8).
8), thereby oxidizing and decomposing the components of the NO _X and odor at photocatalyst.

In the above-described determination of whether the pollution degree is high in step 74, when it is determined that the pollution degree is low (No in S74), the process proceeds to step 80, and it is determined whether the internal air circulation. . Here, when the outside air introduction is set and a large amount of air has to be purified (S80 is N
o), the pattern (a) of the activated carbon filter 32 shown in FIG.
In each of the characteristics (e) to (e), the maximum air flow rate is set by searching the map shown in FIG. 7 in the range where the removal rate is the highest (S82). For example, when it is determined that the characteristic is the pattern (b), the maximum air flow rate 270 L / min capable of exhibiting the maximum removal rate of 60% is set. On the other hand, when it is determined in step 80 that the inside air circulation is set and only the air in the vehicle needs to be purified (S80 returns Yes.
s), in each characteristic of the activated carbon filter 32 shown in FIG. 6, the amount of air blown is set within the range in which the removal rate is maximum (S8).
4). For example, 100 L / min that can exhibit the maximum removal rate even if the characteristic is the pattern (e) is set for the characteristic patterns (a) to (d). Then, based on the set value, the motor controller 52 PWM-controls the motor 42 to blow the target value (S86). Through the above process, the purification process subroutine shown in step 70 of FIG. 2 is terminated and it is determined whether the start switch has been turned off (S90 shown in FIG. 2). Unless the switch is turned off, the process returns to step 14 and the process described above is performed. Repeat the procedure to continue purifying the air.

If the adsorbing performance of the activated carbon filter 32 is saturated by continuing to purify the air, for example, if the internal air circulation is set at the time t3 shown in FIG. 5 (FIG. 3).
(Yes in S32), the difference in the degree of pollution of the air before and after passing through the activated carbon filter 32 becomes smaller than the second value (No in S34). Alternatively, if the outside air introduction is set at the time t2 shown in FIG.
o), the difference in pollution degree before and after the activated carbon filter 32 becomes smaller than the first value (No in S36). As a result, the regeneration operation of the activated carbon filter 32 is started.

Here, first, after turning on a display lamp (not shown) provided on the instrument panel of the driver's seat for indicating the regenerating operation (S38), ultraviolet rays emitted from the metal halide lamp (ultraviolet lamp) 36 shown in FIG. 1 are irradiated. By increasing the surface temperature of the adsorption filter 32 (S40), the adsorbed substance is desorbed to regenerate the activated carbon filter 32,
Moreover, by increasing the activity of the photocatalyst, the oxidation / decomposition by the photocatalyst is further promoted, and NO _X adsorbed on the activated carbon is increased.
Remove odorous components such as. At this time, the temperature sensor 3
It is judged from the signal from 8 whether the surface temperature of the activated carbon filter 32 has reached the set temperature (for example, 80 ° C) (S4).
2) Until the set temperature is reached (No in S42), the surface temperature is increased by stopping the fan 40 so as not to blow air. When the set temperature is exceeded (Yes in S46), the fan 40 is rotated at a low speed (S4).
6) Cool the activated carbon filter 32. That is, in steps 42, 44 and 46, the fan 40 is intermittently operated to keep the surface temperature of the activated carbon filter 32 at the set temperature and prevent the activated carbon filter 32 from being deteriorated due to overheating. At this time, it is determined in steps 48 to 60 whether the regeneration of the activated carbon filter 32 is completed.

In the determination operation in steps 48 to 60, the blowing air is stopped to heat the activated carbon filter 32, and the downstream odor sensor 48 detects the contamination concentration on the outlet side of the activated carbon filter 32, and this value is set. When the maximum value DMAX is exceeded, or when the maximum value DMAX is not exceeded even if the set heating time tMAX is exceeded, the air is restarted to temporarily stop the heating and the activated carbon filter 32 is adsorbed. Determine if performance has recovered. Then, when the adsorption performance is not recovered, the desorption operation by heating is started again.

This process will be described with reference to the flow charts of FIGS. 8 and 3 showing the output voltages of the upstream odor sensor 46 and the downstream odor sensor 48 during the operation. First, as described above, the ventilation is stopped in step 44 (time t3 in FIG. 8 (A)) to start heating the activated carbon filter 32, and the downstream odor sensor 48 controls the outlet side of the activated carbon filter 32. The contamination concentration is detected (S47). Here, at time t4 shown in FIG. 8 (A), when the pollution concentration exceeds the set maximum value DMAX (S50 is Yes), the ventilation is restarted (S52), and the upstream odor sensor 46 activates the activated carbon filter 32. The contamination concentration on the inlet side of the
6) The downstream odor sensor 48 detects the contamination concentration on the output side (S58). Then, it is determined whether or not the ratio of the contamination concentrations on the inlet side and the outlet side is larger than a preset third value (S60). When the adsorption performance of the activated carbon filter 32 is not sufficiently recovered and the ratio of the pollution concentrations is smaller than the preset third value (No in S60), the process returns to step 42 and the activated carbon filter 32 starts at time t5. To resume heating. This heat treatment is repeated, for example, three times, and the adsorption performance of the activated carbon filter 32 is restored so that the ratio of the pollution concentration becomes
When it becomes larger than the preset third value (S60 is Y
es), after turning off the above-described display lamp indicating the reproducing operation (S62), weakening the ultraviolet light emitted from the metal halide lamp (ultraviolet lamp) 36 (S6).
4), the reproduction process shown in FIG. 3 ends.

Here, FIG. 8B shows a case where the contamination degree does not exceed the maximum value DMAX even when the preset maximum heating time tMAX is reached. Start heating from time t1,
If heating is continued for the maximum heating time tMAX (time t
12), the determination as to whether or not the predetermined time has elapsed in step 48 described above is Yes, the process proceeds to step 52, and the ventilation is restarted as described above, and the contamination concentrations on the inlet side and the outlet side are detected (S56, S58). , It is determined whether or not the regeneration is completed depending on whether or not the density ratio exceeds the third value.

In the first embodiment, the degree of pollution before and after passing through the activated carbon filter 32 detected by the upstream odor sensor 46 and the downstream odor sensor 48 is compared, and the adsorption capacity is lowered and the activated carbon filter 32 is reduced. Since the desorption of the adsorbed substance is started when the difference in the degree of contamination before and after the reduction becomes small, the activated carbon filter 3
2 playback can be started. Similarly, at the time of regeneration, the degree of contamination before and after passing through the activated carbon filter 32 is compared, and regeneration of the activated carbon filter 32 is completed based on the comparison result. Therefore, when the adsorption capacity is actually restored, the activated carbon filter 32 Playback of 32 can be terminated.

Further, in this embodiment, the removal rate of the activated carbon filter 32 is calculated from the contamination degree before and after passing through the activated carbon filter 32 detected by the upstream odor sensor 46 and the downstream odor sensor 48, and the removal rate is calculated. Based on the above, the characteristics of the activated carbon filter 32 are judged, and the air flow rate is determined so as to maximize the removal amount according to the characteristic. Therefore, the air flow rate should be adjusted according to the deterioration of the characteristics of the activated carbon filter 32 due to aging. Thus, it is possible to control the removal amount to be the largest.

In the above embodiment, step 3
In step 6 and step 38, it is determined whether or not the regeneration operation is started based on the density difference between the input side and the output side. Instead, the density ratio between the input side and the output side is calculated and It is also possible to determine whether to start the reproduction operation based on the ratio. Similarly, in step 60, based on the density ratio between the input side and the output side, it is determined whether or not to end the reproducing operation. Instead, the density difference between the input side and the output side is calculated, and It is also possible to end the reproducing operation based on the difference. Further, the adsorption capacity (removal rate) of the activated carbon filter 32 can be obtained by performing calculation such as calculus rather than obtaining the difference or ratio of the sensor outputs before and after the activated carbon filter 32.

Further, in the first embodiment, the activated carbon filter 32 is irradiated with relatively weak ultraviolet light from the metal halide lamp 36 even during the cleaning process, but the ultraviolet light from the metal halide lamp 36 is irradiated only in the regeneration process. Can also be configured.

Next, a second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 4, the air purification device 110 according to the second embodiment includes a blow-out pipe 24 for blowing air into the vehicle and an exhaust pipe 26 for discharging exhaust gas.
A first damper 30 that switches between the blowing pipe 24 and the exhaust pipe 26; a turbo fan 40 for pumping air to the blowing pipe 24 or the exhaust pipe 26; and a DC motor 42 that drives the turbo fan 40. A motor controller 52 for stopping and operating the DC motor 42, and an N formed by supporting a photocatalyst on activated carbon fibers folded in pleats.
Activated carbon filter 32 for adsorbing O _X, CO oxidation catalyst 34 that oxidizes CO into CO ₂ , ultraviolet lamp 36 for irradiating the activated carbon filter 32 with ultraviolet light, and ultraviolet lamp 36 is turned on and irradiated with ultraviolet light. A ballast 50 for switching the amount, a temperature sensor 38 for measuring the temperature of the activated carbon filter 32, and a NO _X sensor 4 for detecting the NO _X concentration of air before and after passing through the activated carbon filter 32.
7, a third damper 63 for switching and sending the air before passing through the activated carbon filter 32 and the air after passing to the NO _X sensor 47, the intake pipe 22 for taking in air from the vehicle interior, The second damper 62 opens and closes the intake pipe 22. The vehicle air purification device 110 is controlled by the control device 60 in the same manner as the first embodiment described above with reference to the flowcharts of FIGS.

In the above-described first embodiment, two odor sensors 46 and 48 are arranged before and after the activated carbon filter 32. Here, the sensors for measuring the degree of contamination have different output characteristics, and output different detection signals (voltage values) in response to changes in the degree of contamination to be detected. Therefore, when separate sensors are used for the upstream and downstream of the activated carbon filter 32, it is necessary to adjust the characteristics of both sensors so that the output characteristics substantially match. On the other hand, in the configuration of the second embodiment, the upstream side and the downstream side of the activated carbon filter 32 are measured by using one NO _X sensor 47 and switching the air blown by the third damper 63. Therefore, the above-mentioned correction of the output characteristic is not necessary, the cost can be reduced, and the contamination degree can be accurately detected.

[0049] In the above embodiments, an automobile air purifier 10, NO _X, but purify harmful substances emitted from other vehicles or the like of the CO, but the present invention is hygroscopic, such as activated carbon or silica gel It goes without saying that the agent can also be used in an air purifying device of the type for purifying a bad smell such as cigarette smoke in a vehicle.

In this embodiment, since the activated carbon is used while desorbing the adsorbed substance, the air can be continuously purified for a long time without exchanging the activated carbon. Furthermore,
Since high heat is not applied during the desorption operation of the adsorbed material, the activated carbon is not deteriorated.

Various lamps can be used as the ultraviolet lamp as long as they can excite the photocatalyst. Furthermore, in the first and second embodiments, TiO ₂ is used as the photocatalyst, but various materials can be used as long as they can oxidize and decompose odorous components. For example, Ti, Cu, Zn, La, M
It can be composed of at least one selected from the group consisting of oxides of o, V, Sr, Ba, Ce, Sn, Fe, W, Mg, or Al, and a noble metal. Furthermore,
The photocatalyst can be supported on an adsorbent such as silica gel instead of activated carbon.

[0052]

[Effect] As described above, in the present invention, the adsorbing ability of the adsorbent is actually measured, and regeneration is performed when the adsorbing ability is lowered. It is possible to maintain high removal ability at all times. On the contrary, since the adsorbent having the remaining adsorbing power is not regenerated, the deterioration of the adsorbent due to the regeneration can be minimized.

Further, according to the present invention, the adsorption capacity of the adsorbent is actually measured, and the regeneration is stopped when the adsorption force is recovered. It can exert its removal ability. On the contrary, since it is not necessary to continue to apply heat to the adsorbent that has been regenerated, deterioration of the adsorbent can be minimized by minimizing the heating time during regeneration.

[Brief description of drawings]

FIG. 1 is a perspective view of an automobile air purification device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a main routine of a process by the automobile air purification device shown in FIG.

FIG. 3 is a flowchart showing a subroutine of reproduction processing shown in FIG.

FIG. 4 is a flowchart showing a sub-routine of the purification process shown in FIG.

FIG. 5 is a graph comparing outputs of an upstream odor sensor and a downstream odor sensor.

FIG. 6 is a graph showing changes over time in the removal rate of an activated carbon filter.

FIG. 7 is an explanatory diagram showing the contents of a correspondence map between the removal rate and the optimum air volume.

FIG. 8 is a graph showing outputs of the upstream odor sensor and the downstream odor sensor during reproduction.

FIG. 9 is a configuration diagram of an automobile air purification device according to a second embodiment of the present invention.

[Explanation of symbols]

 10 Air Purifier 20 Lid 32 Activated Carbon Filter 34 CO Oxidation Filter 40 Fan 42 Motor 46 Upstream Odor Sensor 48 Downstream Odor Sensor 60 Control Device 110 Air Purification Device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masako Sakai 2-19-12 Sotokanda, Chiyoda-ku, Tokyo Equus Research Co., Ltd.

Claims (6)

[Claims] 1. An automobile air purification apparatus for purifying air, comprising an adsorbent for air purification, upstream detection means for detecting the degree of pollution of air before passing through the adsorbent, and the adsorbent. Downstream detection means for detecting the pollution degree of the air after passing through, comparing the pollution degree before and after the passage of the adsorbent detected by the upstream detection means and the downstream detection means, the adsorption based on the comparison result An air purifying apparatus for an automobile, comprising: a desorption unit that starts desorption of the substance to be adsorbed from the agent. 2. The desorption means compares the degree of contamination before and after passing the adsorbent, and when the difference or the ratio of the degree of contamination is smaller than a predetermined value, desorbing the substance to be adsorbed from the adsorbent. The air purification apparatus for an automobile according to claim 1, wherein the air separation is started. 3. The air purification apparatus for an automobile according to claim 1, wherein the upstream detection means and the downstream detection means share one sensor to detect the degree of pollution. 4. A method of regenerating an adsorbent of an air purifying apparatus for an automobile, which purifies air by using an adsorbent for air purification while regenerating the adsorbent, the contamination degree of air before passing through the adsorbent. A step of detecting, a step of detecting the degree of pollution of the air after passing through the adsorbent, a step of comparing the degree of air pollution before and after passing through the adsorbent,
And a step of starting regeneration when a difference or a ratio of the pollution degrees is smaller than a predetermined value. 5. A method of regenerating an adsorbent for an automobile air purifying apparatus, which purifies air by using an adsorbent for air purification while regenerating the adsorbent, wherein the adsorbent is passed through in the regeneration of the adsorbent. The step of detecting the pollution degree of the air before, the step of detecting the pollution degree of the air after passing through the adsorbent in the regeneration of the adsorbent, and the pollution degree of the air before and after passing through the adsorbent And a step of terminating the regeneration of the adsorbent based on the comparison result. 6. The step of terminating the regeneration of the adsorbent compares the pollution degree of air before and after passing through the adsorbent,
The method for regenerating the adsorbent according to claim 5, wherein regeneration of the adsorbent is terminated when the difference or ratio of the pollution levels becomes larger than a predetermined value.