JPH0542297B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is directed to static mixing and transfer of highly viscous fluids under laminar flow conditions in the manufacturing and processing processes of polymer compounds, etc. The present invention relates to a heat exchange type mixing reactor that simultaneously generates heat and heat.

(Prior art) In recent years, the polymerization reaction operations of various polymer compounds have rapidly developed, and a stirring tank with a heat transfer jacket and an internal heat transfer coil attached thereto are used singly or in a plurality. It is widely used in this condition.

However, in any case, these stirred tank type reactors cannot avoid back-mixing phenomena in the tank due to the short pass of the fluid serving as the starting material or conversely due to long residence time, and the reaction time of the solution in the tank is unavoidable. The history of temperature and time is not uniform, and the degree of polymerization of the reaction product tends to vary widely. Furthermore, since the shear rate is different between the outer circumferential portion and the central portion of the stirring blade, there is a drawback that the quality of the reaction product tends to vary widely due to this as well.

In addition, in polymerization reaction operations, as the reaction progresses, its physical properties, such as viscosity, density, specific heat, and thermal conductivity, change. In order to achieve the desired heat transfer and mass transfer, it is necessary to change the rotational speed of the stirring blade to match the progress of the reaction, or to transfer the contents to a reactor with a different stirring blade shape. This requires complicated operations, such as having the user perform the following operations.

On the other hand, in a continuous reactor, multiple rows of heat transfer tubes are bent into a meandering path shape and arranged in parallel and crossing each other in order to perform heat transfer and static mixing at the same time. A continuous tubular reactor is used in which only both ends of the reactor are connected to a heat transfer section on the outer periphery by passing through the channel wall, or are connected to a header.

However, such tubular reactors have the disadvantage that only non-condensable flow pairs can be used as heat transfer medium. This is because, in the case of a heat medium that involves condensation, the condensate generated by condensation accumulates in the curved portion of the meandering pipe, and this condensate cannot be sufficiently extracted. Furthermore, even when using a non-condensable heat medium, if air bubbles get into the heat transfer tube during injection, or if the heat transfer medium changes in quality and generates gas or steam during use, meandering may occur. There is a drawback that the flow of the heat medium in the pipe is significantly blocked at the curved portion, that is, the expected heat transfer ability is not achieved due to the paper locking phenomenon. Furthermore, because it is structurally unavoidable to provide a slight gap between the meandering pipe and the inner wall of the flow path, some of the fluid in the flow path passes through this gap, preventing sufficient mixing and heat transfer. There is also the drawback that the quality of the reaction products varies.

(Problems to be Solved by the Invention) As mentioned above, in a stirred tank type reactor, the quality of the reaction product tends to vary due to the back mixing phenomenon and the difference in shear rate, and the progress of the reaction is likely to vary. There is a problem in that the efficiency of heat transfer and mass transfer decreases due to the accompanying change in physical properties.

In addition, in conventional continuous tubular reactors, there are restrictions on the types of heat transfer medium that can be used, and air bubbles mixed when the heat transfer medium is injected, as well as gas and steam generated due to deterioration during use, can cause the heat transfer tubes to curve. There is a problem that the desired heat transfer ability is not exhibited due to stagnation in the inner wall of the pipe, and there is also a problem that variations in mixing, heat transfer, and reaction are likely to occur due to the short pass phenomenon in the vicinity of the inner wall of the pipe.

The present invention has been made to address the problems of the prior art, and is intended to improve the mixing, heat transfer, and
It aims to homogenize reaction operations and prevent the efficiency of mass transfer and heat transfer from decreasing due to changes in physical properties, and also enables the use of various heat carriers, as well as ensuring that the fluid in the flow path is always under constant shearing action without having to short pass. The object of the present invention is to provide a heat exchange type tubular mixing reactor capable of processing.

[Structure of the Invention] (Means for Solving the Problems) The heat exchange type tubular mixing reaction device of the present invention passes one or more fluid substances through a flow path in which a group of heat transfer tubes is arranged. The device includes a heat transfer section main body having a flow path having a substantially rectangular cross section, and a heat transfer section main body having a flow path that is adjacent to the heat transfer section main body in a plane parallel to opposing inner walls of the heat transfer section main body. a group of heat transfer tubes arranged in a lattice pattern such that they are inclined in different directions and their intersections are close to each other; a guide fin having a width reaching
A single tube structure or a plurality of tube structures each having an extrusion section provided on the outer periphery of the heat transfer section main body so as to supply a heat medium to the heat transfer tube group and to exchange heat through the wall surface of the heat transfer section main body. The feature is that the devices are connected in series.

(Function) In the heat exchange type tubular mixing reactor of the present invention,
The fluid passing through the flow path of the heat transfer section main body undergoes static mixing and heat exchange at the same time as the fluid is repeatedly divided and recombined by a group of grid-shaped heat transfer tubes provided within the flow path. In addition, heat exchange is also performed by the external extraction section. During this process, reactions or heat transfer of the fluid progress, and the physical properties of the fluid (viscosity, density,
Even as changes in specific heat and thermal conductivity progress,
Under constant shear action, the heat transfer tubes and guide fins maintain a plug flow state that does not cause back-mixing, so the conditions are optimal for reaction or heat exchange (temperatures between difference, width of variation in residence time of fluid in the device, etc.)
It becomes possible to drive in As a result, it becomes possible to precisely control the temperature and residence time of the fluid within the apparatus, minimizing undesirable side reactions and deterioration, and improving yield and quality.

(Example) Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a side cross-sectional view of a tube structure that is a constituent unit of a heat exchange type tubular mixing reactor according to an embodiment of the present invention, and FIG. It is a diagram. Moreover, FIGS. 3, 4, and 5 are a front view, a side view, and a plan view thereof.
This tube structure 1 has a flow path 11 with a square cross section, and a group of heat transfer tubes 12 installed in this flow path 11 statically mixes the processing fluid passing through the flow path 11. The heat transfer unit main body 10 performs heat exchange operation with respect to the heat transfer unit main body 10, and a heat medium is supplied into each heat transfer tube of the heat transfer tube group 12, and the heat transfer unit main body 10
It is mainly composed of an external extraction section 20 that performs heat exchange operation through the wall surface of the.

Each heat exchanger tube of the heat exchanger tube group 12 includes a plurality of heat exchanger tube rows 121 parallel to the side wall surface of the heat exchanger main body 10,
122, 123, 124, 125, 126, 12
7, 128, and 129 are installed in the heat transfer part main body 10 so as to be arranged in parallel in the flow path direction shown by the arrow in the figure. Each of these heat transfer tubes penetrates the upper and lower wall surfaces 10a and 10b of the heat transfer section main body 10 and is connected to the external portion 20. In addition, each heat exchanger tube is inclined at a predetermined angle with respect to the flow path direction, each adjacent heat exchanger tube row has an inclination angle in a different direction, and each intersection is arranged in a lattice shape so as to be in contact with each other. . Moreover, in the heat exchanger tubes of each heat exchanger tube row, as shown in FIG.
The heat exchanger tubes 121 at both ends are directly inserted into the
a, 121d are once passed through the coupling tubes 13a and 13b, and are connected to the heat exchanger tubes 122a, 122d at both ends of the adjacent heat exchanger tube row 122 coupled to the coupling tubes 13a and 13b. distribution will take place.

Here, it is preferable that the inclination angle of each heat exchanger tube with respect to the flow path axis is determined based on the following matters.

That is, the pressure loss of the processing fluid passing through the flow path is expressed by the following equation.

Pressure drop △p=C・μ・u・L/d ² (where C is a constant determined by the structure, μ is the viscosity of the fluid, u is the space velocity of the fluid, L is the flow rate, and d
indicates the outside diameter of the heat transfer tube. ) The constant C is related to the inclination angle of the heat exchanger tube. As the inclination angle increases, pressure loss increases, but the heat transfer area per effective unit volume within the flow path increases. Conversely, if the inclination angle is made smaller, the pressure loss will be lowered, but the heat transfer area per effective unit volume in the flow path will be reduced. Further, the effective volume ratio and heat transfer area ratio in such a tubular mixing reactor are determined by the following formulas.

Effective volume ratio: V _A /V (In the formula, V _A is the actual volume excluding the volume occupied by heat exchanger tubes etc. from the internal volume of the flow path, and V is the empty volume within the flow path. The same applies hereinafter. ) Heat transfer area ratio: A _A /V _A (In the formula, A _A indicates the actual heat transfer area in the flow path.) In addition, it is usually preferable that these values be within the following ranges.

V _A /V = 0.75 to 0.90 A _A /V _A = 50 to 90 It is preferable to refer to these values to determine the inclination angle of the heat exchanger tubes, and in normal operation it is approximately in the range of 30 degrees to 60 degrees. Inside is better.

In addition, it is possible to change the values of V _A /V and A _A /V _A depending on the number of heat transfer tube rows and the heat transfer tube diameter. If the diameter of the heat tube is reduced and the number of heat transfer tube rows is increased, the value of V _A /V increases and the value of A _A /V _A decreases.

In this example, the value of V _A /V is 0.78,
The value of V _A /V _A is 80, the inclination angle of the heat exchanger tube is approximately 45 degrees,
The number of heat exchanger tube rows was nine, and the number of heat exchanger tubes in each heat exchanger tube row was four.

Furthermore, as shown in FIG.
A semicircular guide fin 14a having a width reaching each of the heat exchanger tubes 1,129 and inclined in the same direction as each heat exchanger tube of the heat exchanger tube rows 121, 129 at both ends,
These guide fins 14a, 14b, 14c, and 14d prevent the processing fluid from passing near the inner wall of the main body, thereby achieving more uniform mixing.

Furthermore, flanges 15 are installed at each end of the heat transfer section main body 10 in the flow path direction when the tube structures 1 are used in series connection.

The extrinsic part 20 is constituted by an extrinsic pipe 21 installed between the flanges 15 so as to surround the heat transfer part main body 10, and as shown in FIG. Partition plates 22a, 22b, 22 provided between the outer wall of 10 and the inner wall of outer pipe 21
It is separated into an upper extrusion section 20a, a lower excursion section 20b, and side excursion sections 20c and 20d by c and 22d.

The upper exfiltration section 20a includes partition plates 23a, 23b, and It is separated into each chamber by 23c, and each of these chambers is penetrated by a heat medium inflow pipe 25a, 25b, 25c, and 25d, respectively. Similarly, the lower part 20b also has a partition plate 24.
a, 24b, and 24c, each of which has a heat medium outflow pipe 26.
a, 26b, 26c, and 26d are penetrated.

In addition, a flow path 1 is provided in the side external parts 20c and 20d through the wall surface of the heat transfer part main body 10 inscribed therein.
In order to enable a heat exchange operation for the processing fluid passing through the heating medium inflow pipes 27a and 27b,
and outflow pipes 28a, 28b are inserted therethrough.

These heat medium inflow pipes 25a, 25b, 25
c, 25d, 27a, 27b and each outflow pipe 26
a, 26b, 26c, 26d, 28a, 28b
is connected to a heat medium supply facility (not shown), which supplies the heat medium, and exchanges heat with the processing fluid passing through the flow path 11 through each heat transfer tube and the extraction section. An operation, ie heating or heat removal, is performed.

Depending on the treatment operation, one or more of the tube structures 1 having the above structure are connected in series through the flange 15 of the heat transfer section main body 10 to constitute a heat exchange type tubular mixing reaction apparatus. When using a plurality of tube structures 1, as shown in Fig. 6, connect the rows of each heat transfer tube group so that they intersect at 90 degrees, and Preferably, the connections are made such that the forces are applied alternately and repeatedly. This results in more uniform mixing.

In the heat exchange type tubular mixing reactor of this embodiment configured in this way, the heat transfer tube group provided in the flow path and the external A heat exchange operation is performed on the processing fluid from the heat transfer tube group, and a mixing operation is performed by the heat transfer tube group.

Here, due to the lattice-shaped heat transfer tube group provided in the flow path and the guide fins provided on the inner wall of the heat transfer section main body, the flow of the processing fluid becomes a divided flow that intersects the flow path axis at a certain angle, and the flow path The processing fluid within the apparatus always forms a prog flow that is subjected to a constant shearing action, and the residence time of the fluid within the apparatus is maintained in a state with little variation.

In addition, since the boundary layer between the heat transfer tube group surface and the inner wall surface of the heat transfer section main body and the processing fluid is constantly updated due to the effect of the split flow described above, the film heat transfer coefficient in the flow path is This increases significantly compared to the case of empty tubes without groups. Therefore, compared to the case of empty tubes having the same heat transfer area and the same temperature difference, the heat transfer capacity of the heat exchange type tubular mixing reactor of the present invention is significantly increased. Furthermore, since the heat transfer area per effective unit volume within the device can be designed to be a constant value regardless of the size of the device, highly reliable design is possible when scaling up.

Furthermore, because the reactor of this embodiment has a single flow path, the problem of uneven distribution of fluid to each heat exchanger tube, which is often experienced with shell-and-tube heat exchanger types, is completely eliminated.

The reactor of this example can be installed either horizontally or vertically, since the shape of the heat transfer tube is relatively simple and there are no meandering curved parts, so the heat transfer medium used can be drained, degassed, and vented. is easily possible. Therefore, it is possible to use either condensing or non-condensing heat medium as a heat transfer medium, and there is no vapor lock phenomenon caused by gas or steam generated during use, and the desired heat transfer ability is always maintained. is demonstrated.

[Effects of the Invention] As explained above, according to the heat exchange type tubular mixing reaction apparatus of the present invention, the mixing and heat exchange of processing fluids can be performed uniformly, and the efficiency of heat transfer and mass transfer is improved by changing the physical properties of the processing fluid. This can be done without reducing the Therefore, a reaction product with excellent yield and quality can be obtained. Furthermore, there are no restrictions on the heat medium to be used, and there is no reduction in heat transfer ability due to generated gas or steam, so the reactor is highly efficient.

[Brief explanation of the drawing]

FIG. 1 is a side cross-sectional view showing the structure of a tube structure that is a constituent unit of a heat exchange type tubular mixing reactor according to an embodiment of the present invention, and FIG. 2 is a planar direction along the - line in FIG. 1. The sectional views, FIGS. 3, 4, and 5 are a front view, side view, and plan view of FIG. 1, and FIG. 6 is a diagram showing an example of a method of connecting the pipe structure shown in FIG. 1. 1... Pipe structure body, 10... Heat transfer part body, 11...
Channel, 12... Heat transfer tube group, 14... Guide fin,
20... Outer club.

Claims (1)

[Scope of Claims] 1. In an apparatus for mixing and heat exchange by passing one or more types of fluid substances through a flow path in which a group of heat transfer tubes is arranged, the flow has a substantially rectangular cross section. A heat transfer section main body having a channel, and adjacent heat transfer tubes arranged in a lattice shape in a plane parallel to opposing inner walls of the heat transfer section body in the flow channel so as to be inclined in different directions from each other and intersecting portions are close to each other. a group of heat transfer tubes, a guide fin protruding from an inner wall of the heat transfer section main body and having a width substantially reaching heat transfer tubes at both ends of the group of heat transfer tubes, and supplying a heat medium to the group of heat transfer tubes. and an extrusion section provided on the outer periphery of the heat transfer section main body so as to exchange heat through the wall surface of the heat transfer section main body. Heat exchange type tubular mixing reactor.