The present invention relates to a reaction system, and particularly to a reaction system for conducting one or more reactions.
In materials research, a great deal of screening research is often needed to determine suitable material synthesis reactions and various properties of materials. For example, to select a catalyst for use in a particular application, a large number of potential catalysts are screened to determine which catalysts have the most desirable rate of reaction at specified conditions, the conditions at which the rate of reaction is maximized, and the proportion by which a given catalyst favors a desired reaction compared to other possible undesirable reactions.
In one conventional screening process, potential catalysts are evaluated sequentially. First of all, different catalysts are evaluated under the same conditions. A micro reactor or pilot plant is used to evaluate a catalyst at specified conditions. Upon completion of an experiment, the catalyst involved is removed and the experiment is repeated with the next catalyst, until a suitable catalyst is found. The experiments can then be repeated at varying conditions until optimal conditions for that suitable catalyst are found. Sequential testing in this manner can be very time-consuming and require significant resources.
To solve the above problem, in another conventional process, multiple reactions are performed in parallel perform in multiple reactors. Using this process, a large number of reactions can be simultaneously performed to synthesize, screen and evaluate catalysts, so that efficiency is enhanced. For the evaluation to be useful, however, the conditions across the multiple reactors must be substantially the same. One of the important conditions is reaction temperature.
Various methods can be used to control temperature. One conventional method is to independently control the temperature for each one of the multiple reactors. A drawback of this method is the high cost for constructing, monitoring and controlling separate reactors. Moreover, particularly in more temperature sensitive reactions, slight variation across different reactors may cause variance in the multiple reactions. Therefore, this method is not suitable to temperature sensitive reactions.
To ensure substantially same temperature across multiple reactors, attempts have been made in the art to construct multiple reactors from a single block of metal or similar conducting material. The temperature of the entire block of multiple reactors can then be controlled by heating or cooling the block as a whole, and allowing the block to reach equilibrium to ensure temperature uniformity across the multiple reactors. However, drawbacks with constructing multiple reactors from a single block of metal include the expense of machining multiple reactors in the block and the large weight of the final apparatus. Moreover, as the size of the individual reactors increases and the block weight increases accordingly, this method becomes more and more difficult in practice. Moreover, more energy is required for the heating and cooling of whole block of metal. Finally, since heat may be lost through conduction, convection or radiation, it is difficult to accurately control the temperature during heating and cooling.
Therefore, there is a need to provide a system that is able to precisely control the temperature and the uniformity of temperature across multiple reactors and to minimize heat loss or gain or fluctuation among the reactors.
An object of the present invention is to provide a reaction system which requires less energy and shorter time to reach equilibrium.
Another object of the present invention is to provide a reaction system which is able to ensure that temperature is uniformly distributed across reaction chambers.
Yet another object of the present invention is to provide a reaction system which is able to reduce heat loss, gain or fluctuation among reaction chambers.
Yet another object of the present invention is to provide a reaction system with a relatively smaller total weight.
In order to achieve the above objects, a reaction system is provided and the system includes reaction chambers, a temperature controller thermally coupled to the reaction chambers, an insulator thermally coupled to the reaction chambers, and a heat radiation shield. The insulator includes a vacuum environment.
Compared with existing technologies, the reaction system is provided with a heat radiation shield and an insulator including a vacuum environment and therefore has the advantages of requiring less energy and shorter time in reaching equilibrium, ensuring uniform temperature distribution, and reducing heat loss, gain or fluctuation among reaction chambers.
In the above system, the temperature controller includes first temperature control elements thermally coupled to a first side and a second side, respectively, of the reaction chambers. The reaction system may further include a temperature sensor. Multiple reaction chambers in the system may be placed in parallel with each other, and each substantially equidistant from the reaction chambers adjacent to it, and all equidistant from a shell of the system. The reaction system may further include an opening to selectively replace the vacuum environment with a fluid to rapidly change the temperature of the system.
In order to achieve the above objects, a reaction system is provided and the reaction system includes at least one reaction chamber, temperature control elements thermally coupled to two sides, respectively, of the at least one reaction chamber, and an insulator thermally coupled to the at least one reaction chamber.
Compared with existing technologies, the reaction system is provided with a temperature controller thermally coupled to two sides of the at least one reaction chamber and an insulator and therefore has the advantages of requiring less energy and shorter time in reaching equilibrium, ensuring uniform temperature distribution, and reducing heat loss, gain or fluctuation among reaction chambers, and having a smaller weight.
The reaction system may further include a heat radiation shield and/or a temperature sensor. The insulator may include a vacuum environment. The temperature control elements thermally coupled to two sides of the reaction chamber may be part of a same temperature control element. Similarly, the reaction system may further include an opening to selectively replace the vacuum environment with a fluid to rapidly heat or cool the system.
In order to achieve the above objects, the present invention further provides another reaction system that includes a multiple of the above reaction systems arranged in arrays.
A detailed description of specific embodiments of the invention will be rendered hereafter with reference to the drawings. But the specific embodiments do not constitute any limitation on the scope of the claims.
a) is a view of a cross-section of a reaction system containing reaction tubes according the present invention.
b) is a structural view of a reaction tube and a holder, the reaction tube being partially omitted in the drawing along its longitudinal direction.
c) is a structural view of another reaction tube and holder, the reaction tube being partially omitted in the drawing along its longitudinal direction.
d) is a structural view of yet another reaction tube and holder.
e)-6(h) are schematic views of hanging style holders, respectively.
Referring to
The system includes a plurality of reaction chambers 25. In this embodiment, the system has sixteen reaction chambers 25. The reaction chambers 25 are hollow cylindrical containers used to receive catalysts, reactants or other materials. Each reaction chamber 25 has a top 35 and a bottom 40. The top is placed at the top plate 5 of the shell 20 and the bottom 40 is placed at the bottom plate 10 of the shell 20. The top 35 and bottom 40 may be fastened to the top plate 5 and the bottom plate 10, respectively, of the shell 20 by way of welding, meshing or other connection methods, or may be integrally formed with the top plate 5 and bottom plate 10, respectively, of the shell 20. Each reaction chamber 25 is parallel with a center axis 30 of the shell 20, and the reaction chambers 25 are in a circular arrangement within the shell 20 such that each reaction chamber 25 is equidistant from the reaction chambers 25 adjacent to it and all of the reaction chambers 25 are equidistant from the center axis 30 of the shell 20 and/or from an outer wall 15 of the shell 20.
Referring to
Additionally, the reaction system may be provided with a thermal buffer member between the temperature control elements and the reaction chambers. For example, in a reaction system as shown in
In the current embodiment, the first temperature control elements 45 and 50 are single elements thermally coupled to the top plate 5 and the bottom plate 10 respectively, therefore by heating or cooling the top plate 5 and the bottom plate 10 temperature of each reaction chamber 25 may be caused to change (become hotter or cooler) such that the reaction chambers 25 can carry out same or different reactions in a same temperature. Alternatively, the temperature controller may be configured in other manners, such as configured as a plurality of separate pairs of temperature control elements 45 and 50, each thermally coupled to the top 35 and the bottom 40 of a respective reaction chamber 25. The temperature monitor may separately or wholly monitor the temperatures of the temperature control elements 45 and 50 according to actual needs, such that one or some or all of the reaction chambers 25 may be independently controlled. The temperature control element 45 or 50 as used herein may include, without limitation, one or more temperature control elements, heating elements, cooling elements or any elements may cause a change in temperature of anything to which it is thermally coupled, such as automatic temperature controllers, manual temperature controllers, heaters, and refrigeration units.
Referring to
In the current embodiment, the top plates 5, the bottom plates 10, the outer wall 15, the top 35, the bottom 40, and the one or more reaction chambers 25 are made from materials with high thermal conductivity.
The reaction system may be wholly placed in a housing. The housing may have temperature control function such that the outer wall 15, the top plate 5 and the bottom plate 10 of the system are heated or cooled to a desired temperature. The housing may have heat preservation function to reduce heat exchange between the system and an outside environment.
The reaction system further includes several elements to prevent unintended heat loss or gain through conduction, convection, or radiation and ensure the thermal stability of the system. In the current embodiment, the reaction system uses a cylindraceous outer shield 55 as shown in
Further, the reaction system may employ an inner shield (not shown). The inner shield is placed inside of the reaction chambers 25 to prevent radiation towards the inner section of the shell 20.
The surface of the outer shield 55 or inner shield may be coated with a material or may be constructed of a material that prevents or reduces radiation such as a reflective material or reflective insulation. Reflective materials include radiant barriers and reflective insulations. A radiant barrier is a single sheet of reflective materials. Reflective insulation is an insulating system of reflective sheets and insulator designed together act as insulation. Thus, reflective insulation would consist of a number of layers insulator and reflective sheets. Examples of reflective materials include without limitation, reflective foils, stainless steel, high-temperature metal alloy, and other metal or non-metal materials known in the art that can be made to have a smooth surface and are reflective to infra-red or visible light.
Referring to
The outer shield 55 may be used in combination with the insulator 65 and the outer shield 55 may be placed inside the cavity containing the insulator 65. Further, several inner and/or outer shields 55 may be employed in combination with or without an insulator 65 consisting of several cavities to reduce heat loss or gain in the reaction system. The outer shield 55 may be provided with through holes 550 to connect insulators 65 inside and outside the outer shield 55.
Optionally, the reaction system may comprise one or more guiding portions adapted to introduce or remove reactants, catalysts or any other material to or from the reaction chambers 25. Said guiding portion may be configured in any manner, such as may be configured as guiding pipes, channels or openings, if only the guiding portions may not substantially interfere with the heat conserving aspects of the embodiment or that the system may return rapidly to equilibrium after introduction or removal of the guiding portions. Additionally, the guiding portions could be used to alter the temperature of the system by providing the guiding portions at a desired temperature, for example by preheating or precooling the guiding portions. The guiding portions may be at the top 35 and/or bottom 40 of each reaction chamber 25 and may be a single guiding portion for each reaction chamber 25 or multiple guiding portions for each reaction chamber 25 or any variance thereof. Moreover, the guiding portions may include a preheater or precooler to preheat or precool the material prior to the material's introduction to the reaction chambers 25. Through the use of such guiding portions the system may be configured to be a batch or continuous process or any combination thereof, such as a semi-batch or semi-continuous process.
Referring to
Referring to
As shown in
Materials suitable for use in constructing the reaction chambers 25 or other parts of the system include any that can withstand the temperatures, pressures and chemicals, such as acids, bases, or other reactive compounds. Examples of said materials include metals and their alloys, including but not limited to various grades of steel and stainless steel, super alloys, engineering plastics, ceramics, composite materials, polymers, or a combination of any of the foregoing.
Temperature ranges for use in the present embodiment include from about ambient temperature to about 600° C., from about ambient temperature to about 800° C., and from about ambient temperature to about 1000° C., from about ambient temperature to about 1200° C., from about ambient temperature to about 1400° C. In addition, it is contemplated that the present embodiment may also be used for temperature ranges from well below ambient temperature to well above ambient temperature depending on the particular application.
Advantages of the current configuration include a reduction in energy to heat the system to equilibrium, a reduction in the time for the system to come to equilibrium or to cool down, improved uniformity of temperature throughout the system and in particular in each reaction chamber, and a decrease in the weight of the overall system.
Because the rate of heat transfer, whether through conduction, convection or radiation, is dependent on the temperature difference between the higher temperature area and the lower temperature area, another embodiment of the current invention is provided to reduce said temperature difference and thus reduce the rate of heat transfer, either loss or gain.
A relationship between temperature and a rate of heat transfer through conduction can be seen in the following formula:
wherein:
A relationship between temperature and a rate of heat transfer through convection can be seen in the following formula:
q=KA(Thot−Tcold) (2)
wherein:
A relationship between temperature and a rate of heat transfer through radiation can be seen in the following formula:
P=eσA(Trad4−Tcold4) (3)
wherein:
In another embodiment, the system as shown in
In the reaction system, catalysts, reactants or other materials may be directly loaded in the reaction chamber 25. Or maybe a reaction tube is added, and the catalysts, reactants or other materials are firstly loaded in the reaction tube and then the reaction tube is assembled in the reaction chamber 25. Where the reaction tube is added, front-end pipeline and back-end pipeline of the system may be connected to the reaction tube via couplings and connectors, and compared with direct connection with the reaction chamber 25, such a connection with the reaction tube is more convenient and reliable. Moreover, by using the reaction tube, different experiment request may be satisfied by replacing the reaction tube with another one, but replacing of the reaction chambers 25 or the system is no longer needed, and therefore applications of the system become more flexible. Further, the use of the reaction tube also can make loading and cleaning of the catalysts or the likes become more conveniently.
A holder may be provided in the reaction tube or the reaction chamber to hold the catalysts, reactants or other materials that are loaded into the reaction tube or the reaction chamber. The holder may include a holding element that is substantially perpendicular to the extending direction of the reaction tube or the reaction chamber, and a supporting element that is used to support, fasten, or hang the holding element.
Since situations are similar whether the holder is mounted in the reaction tube or in the reaction chamber, hereafter only a situation that the holder is mounted in the reaction tube is described.
An embodiment of holder is shown in
If the reaction tube 27 is a reducing tube having different cross sections, the step portion 272 may be formed at boundary between tube portions with different cross sections (as shown in
The holding element 274 may be net sieves, sand cores, or any other elements which can be used to hold catalysts, reactants or other solid materials but allow fluids (gases or liquids) to pass over. The supporting element 275 may be a length of pipe (as shown in
In another embodiment, the holder may be hung in the reaction tube by the supporting element. The supporting element may include at least one hanging limb and a rod (as shown in
In the above two embodiments, The holder may further include a force receiving portion for receiving forces from an outside of the reaction tube, so as to facilitate taking the holding element and (or) the supporting element out of the reaction tube after the reaction is finished.
The force receiving portion may be located at the holding element. For example, as shown in
The force receiving portion also may be located at the supporting element. For example, as shown in
Particularly, the force receiving portion may be located at a joint of the holding element and the supporting element. For example, as to the hanging holders as shown in
The force receiving portion also can be formed separately from the holding element and the supporting element. For example, as shown in
Additionally, as shown in
The connector 29 at the end of the smaller tube 271 is relatively smaller and it may be configured smaller than the inside diameter of the reaction chamber 25 and therefore is allowed to pass through the reaction chamber 25, such that the reaction tube 27 can be conveniently assembled and detached. Referring to
Materials suitable for use in constructing the reaction tube 27, the holding element 274 or the supporting element 275 include any that can withstand the high temperatures, pressures and chemicals, such as acids, bases, or other reactive compounds. Examples of said materials include metals and their alloys, including but not limited to various grades of steel and stainless steel, super alloys, engineering plastics, ceramics, composite materials, polymers, or a combination of any of the foregoing.
In the current embodiment, the reaction system includes sixteen reaction chambers 25. However, any number of reaction chambers 25 may be employed. For example, a second embodiment as shown in
In the above embodiments, the reaction chambers 25 may be configured such that they are equidistant from one another as set forth above in the embodiment of
It is contemplated that in any system configuration, all reactor chambers need not be in use at the same time.
As described in the above embodiments, by setting the insulator 65 around the reaction chamber 25, heat exchange through conduction or convection is prevented. For example, where a vacuum is used as an insulator, there is almost no heat convection and also the heat conduction is very little because the heat conductivity of the vacuum is very low. By setting the outer shield 55 and/or the inner shield, heat exchange through radiation is prevented.
Therefore, in the system of the present invention, three ways of heat transfer, i.e., conduction, convection and radiation, is greatly prevented. Thus heat exchange between the reaction system and the outside environment is reduced, heat stability of the system is ensured, and reaction temperature is prevented form changing over time. Furthermore, since temperature effect to the system from the outside environment is almost eliminated, temperature distribution along each reaction chamber 25 mainly depends on the temperatures of the temperature control elements 45 and 50 and heat conductivity of the reaction chamber 25. In a case that the top 35 of each reaction chamber 25 is at a same temperature, the bottom 40 of each reaction chamber 25 is also at a same temperature, and all the reaction chambers 25 are configured to have a same structure, configured from the same material and have a same heat conductivity, the reaction chambers 25 may have a substantially same temperature within a cross section of the system taken perpendicular to the extending directions of the reaction chambers 25. That ensures the reaction chambers 25 have a substantially same temperature at corresponding positions, such that the reaction chambers 25 are ensured to have a substantially same reaction temperature.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CN06/02436 | 9/18/2006 | WO | 00 | 7/1/2009 |