JP2003047839A - Micro reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro reactor capable of stably achieving a chemical reaction (micro chemical reaction) in a micro channel according to the velocity and flow rate of a fluid that flows through the micro channel. SOLUTION: A plurality of micro heaters 4 are disposed in a micro channel 1 forming a fluid conduction passage along the fluid conduction direction and a prescribed number of micro heaters sequential in the fluid conduction direction in the micro channel among the micro heaters are selectively electrified with a heater control section 7. Each of the micro heaters has a length equal to integral multiples of a previously set unit length and the micro heaters are arranged in the order of increasing length along the fluid conduction direction of the micro channel.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a microreactor capable of stably realizing a chemical reaction (microchemical reaction) in a minute space under predetermined reaction conditions.

[0002]

2. Related Background Art A microreactor introduces two or more kinds of reactive fluids (liquid or gas) into a microchannel forming a fluid passage having a minute passage cross-sectional area, and these fluids are mutually introduced. When brought into contact with each other, a microchemical reaction occurs. Such a microreactor is used, for example, for detection of a specific substance accompanied by biochemical reaction, analysis of chemical reaction mechanism in a micro region (microspace), and further production of chemical substance.

[0003]

By the way, a plurality of microreactors used in a microchemical plant are generally incorporated in a flow system for controlling the reaction system. Incidentally, the control of the flow system is realized, for example, by controlling the fluid pressure generated by a pump or the like while monitoring the flow rate of the entire system. Therefore,
Although the flow rate of the entire system is determined, it is difficult to individually set the flow rate (flow velocity) of the fluid flowing through each of the plurality of microreactors. In other words, the flow rate (flow velocity) in each microreactor is determined exclusively by other constraints in the entire flow system.

Then, it cannot be denied that the microchemical reactions in a plurality of microreactors differ from each other depending on their flow rates (flow velocities). That is, if the flow rate (flow velocity) in each microreactor is different, the residence time of the fluid in each microreactor changes. For example, if the velocity of the fluid flowing in the microchannel is high, the residence time of the fluid in the microchannel is short. Therefore, it becomes impossible to cause a sufficient microchemical reaction. In particular, when a microchemical reaction is generated while heating a fluid supplied to the micro-micro channel using a heater incorporated in the micro-channel, the heating amount (heating time) of the fluid by the heater changes depending on its flow rate, There is a risk that a sufficient reaction will not occur.

Therefore, it is conceivable to individually design each microreactor according to the specifications (flow rate) of each part in the flow system. However, it is unrealistic from the viewpoint of cost to design and manufacture a plurality of types of microreactors according to the flow rate (flow velocity) in each part of the flow system. It is also conceivable that a problem such as clogging of the microreactor (microchannel) may occur and flow of the fluid may be hindered, and the flow velocity may change. Therefore, there is a demand for the development of a microreactor suitable for causing a chemical reaction of a fluid to occur sufficiently stably regardless of the speed and flow rate of the fluid supplied to the microchannel, and further, the residence time of the fluid in the microchannel. .

The present invention has been made in consideration of such circumstances, and an object thereof is to make a chemical reaction time of a fluid (a chemical reaction occur in a micro heater) in accordance with a velocity and a flow rate of a fluid flowing through a microchannel. It is an object of the present invention to provide a microreactor capable of controlling a region length to be controlled) and stably realizing a chemical reaction (microchemical reaction) in the microchannel.

[0007]

In order to achieve the above-mentioned object, the present invention changes the length of a heating region in a microchannel so that the time required for a fluid to pass through the heating region of the microchannel. In other words, the characteristic feature is that the residence time of the fluid in the chemical reaction region (heating region) is made constant, and thereby a stable microchemical reaction environment is realized regardless of the velocity or flow rate of the fluid flowing through the microchannel.

Therefore, the microreactor according to the present invention is
A plurality of micro-heaters are arranged along the fluid flow direction of the micro-channel forming a fluid flow path, and in the heater control section, the micro-heater is continuous in the fluid flow direction of the micro-channel among the plurality of micro-heaters. It is characterized by selectively energizing a predetermined number of micro heaters.

In a preferred aspect of the present invention, a plurality of micro-heaters provided in each of the micro-channels have a length that is an integral multiple of a preset unit length. The micro heaters are arranged along the fluid flow direction of the micro channels so that their lengths become longer in order. Further, as described in claim 3, in the heater control unit, the microheater that selectively energizes according to the flow velocity of the fluid guided to the microchannel is controlled, and the heating region length by the microheater and its heat generation are controlled. It is configured to vary the amount.

The microreactor according to the present invention is further characterized by further comprising a micro temperature sensor arranged in the microchannel. The heater control unit controls the amount of heat generated by the micro-heater according to the temperature of the micro-channel detected by the micro-temperature sensor.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A microreactor according to an embodiment of the present invention will be described below with reference to the drawings. Figure 1
FIG. 2 is a diagram showing a basic schematic configuration of a microreactor according to this embodiment. This microreactor is realized by, for example, using a Si semiconductor substrate as a base and forming microchannels 1 forming a fluid flow path on the Si semiconductor substrate by using a micromachining technique. This micro channel 1 has, for example, two inlets 2a and 2b.
And a single outlet 3 are connected to each other to form a liquid flow passage having a predetermined flow passage cross-sectional area. The fluids to be detected respectively input from the inlets 2a and 2b are mixed with a reaction reagent to cause a micro reaction. After that, it plays a role of discharging the reaction solution from the outlet 3.

In this microchannel 1, however, a plurality of microheaters 4 (4a, 4b, to 4n) are arranged along the fluid flow direction. These micro heaters 4a, 4b, to 4n are formed on the Si semiconductor substrate by Si.
For example, a platinum (Pt) thin film having a thickness of about 1 μm, which is provided through an insulating thin film made of O ₂ or the like, and has a length that is an integral multiple of a preset unit length. It plays the role of heating the flowing fluid. In particular, these micro heaters 4a, 4b, to 4n
Are arranged along the fluid flow direction of the microchannel 1, for example, from the upstream side to the downstream side so that the length thereof becomes longer in order.

Incidentally, each of the micro heaters 4a, 4b, to 4n
Specifically, as illustrated in FIG. 2, platinum (P
t) consists of a thin-film conductor meandering in a meander shape,
By taking out the electrode lead for each predetermined folded portion,
It has a structure divided into a plurality of micro heaters 4a, 4b, to 4n having different heater lengths (heat generation area lengths). And, for these micro heaters 4a, 4b, to 4n, the energization section is specified by selecting two of the electrode leads,
As will be described later, only a predetermined number of micro heaters 4 which are continuous in the fluid flow direction in the micro channel 1 are selectively driven to generate heat.

A micro temperature sensor 5 made of platinum (Pt) is arranged in the micro channel 1, and the micro temperature sensor 5 allows the micro channel 1 to flow through the micro channel 1 and the micro heaters 4a, 4b ,. 4n
The temperature of the fluid heated by is monitored. Also in this micro temperature sensor 5, a platinum (Pt) thin film conductor having a predetermined width is meandered in a meandering shape, similarly to the above-described micro heaters 4a, 4b, to 4n, and an electrode lead is provided at each predetermined folding portion. The structure may be divided into a plurality of micro temperature sensors 5a, 5b, to 5n having different temperature detection regions by taking them out.

More specifically, as shown in FIG. 3, platinum (P) having a predetermined width (width) is meandered in a meandering shape as described above.
t) The micro temperature sensor 5 may be arranged along the micro heater 4 on which the thin film conductor is arranged. Then, the temperature of the region where the micro heaters 4a, 4b, to 4n are respectively provided is adjusted to a plurality of micro temperature sensors 5a and 5n.
It suffices to detect each of b and 5n.

The micro temperature sensor 5 having such a structure
According to (5a, 5b, to 5n), the overall temperature (average temperature) in the micro channel 1 and the micro heater 4
It is possible to easily detect the temperatures of the regions provided with a, 4b, and 4n, respectively. It is also possible to provide the micro temperature sensor 5 on the downstream side or the upstream side of the micro channel 1 so as to detect the temperatures of the inlet side and the outlet side of the fluid introduced into the micro channel 1, respectively.

On the other hand, in this microreactor,
A flow sensor 6 is provided so as to be connected to the outlet 3, and the flow sensor 6 monitors the speed and flow rate of the fluid flowing through the microchannel 1. The heating control unit (heater control unit) 7 responds to the temperature of the fluid detected by the micro temperature sensor 5 (5a, 5b, to 5n), and the speed and flow rate of the fluid detected by the flow sensor 6. The plurality of microheaters 4a, 4b, to 4n described above are selectively energized to drive heat generation, thereby controlling the amount of heat applied to the fluid flowing through the microchannel 1.

Although the micro channel 1 is formed on the basis of the Si semiconductor substrate here,
It is also possible to form the microchannel 1 with a metal or a metal base such as SUS steel. However, in this case, the plurality of micro-heaters 4a, 4b, to 4n and the micro-temperature sensor 5 described above are arranged and formed on the metal base via the thin-film insulator layer so as to be integrated in the micro-channel 1. Just do it.

As described above, the microchannel 1
, A plurality of micro-heaters 4a, 4b, to 4n arranged along the fluid flow direction, and these micro-heaters 4
The heat generation drive by the selective energization by the heating control section 7 of a, 4b, to 4n will now be described in some detail. The plurality of microheaters 4a, 4b, to 4n described above are set to a length that is an integral multiple of the unit length of the heat generation region as [1],
For example, two microheaters 4a and 4b having a length [1], two microheaters 4c and 4d having a length [2], two microheaters 4e and 4f having a length [4], and a length [8] Two
It consists of one micro-heater 4g and 4h. These eight micro-heaters 4a, 4b, to 4h are linearly formed so that their lengths gradually increase from the upstream side to the downstream side along the fluid flow direction of the micro-channel 1. It is arranged. The heating control unit 7 selectively energizes each of the micro heaters 4a, 4b, to 4h in units of a predetermined number of micro heaters 4 continuous in the fluid flow direction in the micro channel 1. By this, the length of the heating region (heating zone) by the micro heater 4 in the micro channel 1 is adjusted. Incidentally, the plurality of micro heaters 4a, 4 described above
It is also possible to arrange b, 4 h from the upstream side to the downstream side of the microchannel 1 in a linear fashion so that the length thereof becomes shorter in order.

Specifically, the heating control section 7 is continuous in the fluid flow direction of the microchannel 1 from the eight microheaters 4a, 4b, to 4h arranged in a line in a straight line. The group of 1 to 8 micro-heaters 4 is shown in FIG.
(a) to (v) are selectively extracted as shown by hatching,
The length of the heating region in the micro-channel 1 is changed by energizing the group of the micro-heaters 4 collectively.

And two micro heaters 4 of length [1]
By energizing only one of a and 4b, the length of the heating region is set to [1] as shown in FIG. 4 (a), and only one of the two micro heaters 4c and 4d having the length [2] is set. By energizing, the length of the heating region is set to [2] as shown in FIG. 4 (b). Further, two micro heaters 4b having a length [1] and a micro heater 4c having a length [2] that are adjacent to each other are integrated into one unit, and the micro heaters 4b and 4c are collectively energized, As shown in FIG. 4 (c), the length of the heating region is [3], and two micro heaters 4c and 4d having a length [2] adjacent to each other are made into one unit, and these micro heaters 4c and 4d are provided. As shown in FIG. 4 (d), the length of the heating region is set to [4] by energizing all at once.

Further, the heating control unit 7 includes the microchannel 1
By selectively extracting a group of 2 to 8 micro-heaters 4 which are continuous in the fluid flowing direction of
As shown in FIGS. 4 (e) to 4 (v), the length of the heating region in the microchannel 1 is selectively set as [5], [6] to [30]. And as a whole, the heating control unit 7 changes the length of the heating region in the microchannel 1 to [1], [2], [3], [4], [5], [6], [8],
[9], [10], [12], [13], [14], [16], [18], [2]
0], [21], [22], [24], [26], [28], [29], [3]
0] is set as 22 patterns.

As shown in FIG. 4 (w), two micro heaters of length [1] are added next to the micro heaters 4a and 4b, and four micro heaters of length [1] are made continuous. If it is provided, it is easy to set the heating regions having the lengths [7], [11], [15], and [23]. Although not particularly shown in this example, if one micro heater of length [1] is added next to the micro heater 4h of length [8], heating of length [25], [27] It is also possible to set the area.

In this way, the plurality of micro-heaters 4 arranged along the fluid flow direction are selectively energized to the micro-channel 1 to adjust the length of the heating region in the micro-channel 1. According to the microreactor configured to obtain the heat quantity applied to the fluid supplied to the macro channel 1 can be easily adjusted only by selectively controlling the energization of the plurality of micro heaters 4.
In particular, by selectively energizing the plurality of micro-heaters 4 according to the velocity of the fluid flowing in the micro-channel 1 and the flow rate thereof, the amount of heat given to the fluid can be made constant.

Specifically, when the velocity of the fluid flowing through the microchannel 1 is slow and the residence time of the fluid in the microchannel 1 is long, the heating area by the microheater 4 is shortened and the velocity of the fluid is increased. When the residence time of the fluid in the microchannel 1 does not seem to be short, by setting the heating region by the microheater 4 to be long, the amount of heat given to the fluid per unit volume regardless of the flow velocity (residence time) thereof. Can be made constant.

Incidentally, by monitoring the flow rate of the fluid flowing through the microreactor (microchannel 1) and the pressure loss thereof, the actual flow velocity of the fluid (reactant) in the microchannel 1 can be obtained. Therefore, if the length of the heating region formed by the microheater 4 is adjusted as described above based on the actual flow velocity, the fluid (reactant) flowing through the microchannel 1 is retained in the heating region for a predetermined time. Will be. That is, since the fluid (reactant) passes through the heating region formed by the micro heater 4 over a predetermined time, it is possible to cause an optimum micro reaction here.

At this time, the heating control section 7 selectively energizes the fluid in accordance with the temperature of the fluid detected by the micro temperature sensor 5 provided on the downstream side of the micro channel 1 or along the micro heater 4. Micro heater 4
If feedback control is performed, the temperature of the fluid can be easily made constant. Further, even if the micro-heater 4 selectively energized by the heating control unit 7 is feed-forward controlled according to the temperature of the fluid detected by the micro temperature sensor provided on the upstream side of the micro channel 1, It can be easily stabilized.

By the way, a plurality of microchannels 1 (1
A, 1B, to 1N) are provided in parallel to form a microreactor, for example, as shown in FIG. 5, a plurality of microchannels 1 (1A, 1B, to 1N) are provided in the same manner as in the first embodiment. The micro heaters 4 (4a, 4b, to 4n) may be arranged along the fluid flow direction. In this case, for example, each micro channel 1 (1
A, 1B, to 1N), each of which has a predetermined number of microheaters 4 (4a, 4b, to 4n), particularly those having the same array position, are connected to the microchannels 1 (1).
A, 1B, to 1N) are commonly connected to form a predetermined number of microheater groups. And in the heating control unit 7,
By setting each of these micro heater groups as one energization unit, each micro channel 1 (1A, 1B, ...
1N), the plurality of micro-heaters 4 respectively arranged are commonly energized and controlled.

At this time, the heating control section 7 collectively energizes a predetermined number of microheaters 4 which are continuous in the fluid flow direction in each of the microchannels 1 (1A, 1B, to 1N). Therefore, a predetermined number of microheater groups formed by the microheaters 4 are selectively energized. This allows each microchannel 1 (1
A, 1B, to 1N) a predetermined number of micro-heaters 4 are energized as in the previous embodiment, and each micro-channel 1
The length of the heating region at (1A, 1B, to 1N) is set respectively.

Therefore, even in a microreactor in which a plurality of microchannels 1 (1A, 1B, to 1N) are provided in parallel in this way, each microchannel 1 (1A, 1B, to 1N).
Since the length of the heating area in N) can be adjusted,
For example, the heating time of the fluid by the micro heater 4 can be optimally adjusted according to the control operation of the flow control system such as a pump that controls the reaction system in the micro chemical plant. Therefore, even when a large number of microreactions of a fluid are generated by using a plurality of microchannels 1 (1A, 1B, ~ 1N) provided in parallel, each microchannel 1 (1A, 1B, ~ 1N) There is an advantage that the reaction environment of the fluid can be collectively and stably optimized.

Further, according to the microreactor constructed as described above, even if the microchannel 1 is clogged, the length of the heating region by the microheater 4 is changed according to the change in the flow velocity due to the clogging. Therefore, it is not necessary to replace the microreactor each time clogging occurs, and the microreactor can be operated for a long time. Therefore, the running cost in the micro chemical plant can be reduced,
Further, the degree of freedom in designing the micro chemical plant itself can be increased, and the design cost can be greatly reduced.

The present invention is not limited to the above embodiments. For example, a heating region (heater 4) set by dividing the microchannel 1 in the fluid flow direction
And the length of the heating area may be determined according to the specifications of the microreactor (microchannel). Further, the number of the plurality of microchannels 1 and the arrangement form thereof can be variously modified, and the point is that the present invention can be variously modified and implemented without departing from the scope of the invention.

[0033]

As described above, according to the present invention, a plurality of micro-heaters arranged along the fluid flow direction in the micro-channel are provided, and these micro-heaters are controlled to be energized and heated so that the micro-channel can be used. Since the length of the heating region is controlled, it is possible to stably realize a chemical reaction (microchemical reaction) in a minute space under predetermined reaction conditions. Moreover, it is possible to provide a microreactor having a high controllability of the heating region length and its heating amount with a simple configuration.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a microreactor according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a micro heater incorporated in a micro channel.

FIG. 3 is a diagram showing an example of a micro temperature sensor incorporated in a micro channel.

4 is a diagram showing a form of length control of a heating region in the microreactor shown in FIG.

FIG. 5 is a schematic configuration diagram of a microreactor according to a second embodiment of the present invention.

[Explanation of symbols]

1 (1A, 1B, ~ 1N) Micro Channel 2a, 2b inlet 3 outlets 4 (4a, 4b, ~ 4n) Micro heater 5 Micro temperature sensor 6 Flow sensor 7 Heating controller (heater controller)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G042 AA01 CB03 GA01 HA05 HA07                       HA10                 4G035 AC01 AE02 AE15                 4G037 CA11 CA18 EA01                 4G075 AA39 AA63 BA05 BD15 CA02                       DA03 EA05

Claims (4)

[Claims] 1. A microchannel forming a fluid flow path, a plurality of microheaters arranged along a fluid flow direction of the microchannel, and a fluid in the microchannel among the plurality of microheaters. A microreactor comprising: a heater control unit for selectively energizing a predetermined number of microheaters continuous in the flow direction. 2. The plurality of microheaters provided in each of the microchannels have a length that is an integral multiple of a preset unit length, and are arranged along the fluid flow direction of the microchannel. The microreactor according to claim 1, wherein the microreactors are arranged so that their lengths become longer in order. 3. The microreactor according to claim 1, wherein the heater control unit controls a microheater that is selectively energized according to a flow velocity of a fluid introduced into the microchannel. 4. The microreactor according to claim 1, further comprising a micro temperature sensor arranged in the microchannel.