JPS626844B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a fluid mixing device, and more particularly to a fluid mixing device comprising a static fluid mixer element and a perforated plate. Conventionally, fluid mixing devices include stirrers, extruders,
Dynamic mixers such as pumps, static mixers without driving parts, or combinations thereof are generally known and are widely used industrially. The fluid mixing device is appropriately selected depending on the physical properties and chemical properties of the substances to be mixed and the purpose of mixing. The purposes of mixing are fluid homogenization, dispersion, chemical reactions, extraction,
There are a wide variety of fluid mixing devices, including mass transfer such as absorption and dissolution, and promotion of heat transfer.Therefore, there are a wide variety of types of fluid mixing devices. In order to achieve these mixing purposes, various improvements have been made to the device structure and mixing conditions such as rotation speed in dynamic mixers. On the other hand, in a static mixer,
It is generally considered difficult to mix materials with significantly different viscosities, and the current solution is to increase the number of elements in a static fluid mixer or to combine a static mixer and a dynamic mixer. This is the only method available, and it requires excessive equipment to achieve the desired mixing purpose, and the construction cost is enormous, which is a major obstacle to making full use of the features of static mixers in terms of applications. . Particularly in the mixing of highly viscous materials, an increase in the number of static fluid mixer elements can significantly increase the pressure drop within the mixing device, creating limitations in device strength and operation, making it virtually impossible to improve mixing efficiency. No method provided. As a result of intensive efforts by the present inventors to solve this problem, they discovered that it could be solved by combining a static fluid mixer element and a perforated plate, and completed the present invention. That is, the present invention provides a fluid mixing device in which a static fluid mixer element and a perforated plate are arranged in a pipe through which a fluid flows, in which the number of static fluid mixer elements (m) is 4≦
Mixing made by sequentially arranging a series of static fluid mixer elements with m≦10 and a perforated plate with a ratio of the sum of all pore cross-sectional areas to the plate cross-sectional area of 0.55 or less along the fluid flow direction. A series of static mixer elements are arranged in the tube so that the number of mixing units is 1 or more and 3 or less, and the number of static mixer elements (m') is 5≦m'≦30. This fluid mixing device is characterized in that it is disposed facing the fluid outlet of the fluid mixing device. In the perforated plate used in the present invention, the ratio of the sum of all pore cross-sectional areas to the plate cross-sectional area is 0.55 or less, and the ratio of the cross-sectional area of one hole to the sum of all pore cross-sectional areas is 0.005 or less. In addition, the static fluid mixer element mixes a high viscosity fluid and a low viscosity fluid, and the total number of disposed elements is preferably 40 or less. The fluid mixing device of the present invention described above mixes a highly viscous fluid with a viscosity in the range of 5000 to 300000 poise at a shear rate of 1 sec ^-1 at the temperature at which mixing is carried out, and a high viscosity fluid with a viscosity in the range of 5000 to 300000 poise at a shear rate of 1 sec -1 and a viscosity at 20°C or a solid at 20°C. It is particularly suitable for mixing with low viscosity fluids having a viscosity in the range of 0.2 to 500 centipoise, measured at a temperature of 5 DEG C. above the melting point of the material. The static mixer elements used in the present invention are mixers without moving parts, such as "chemical equipment".
21 (3) 20 (1979)", the product names are: Static Mixer (manufactured by Kenix), Static Mixing Element (manufactured by Sulzer), Ross ISG mixer, Ross LPD mixer (manufactured by Charles Ross). , the same square mixer (manufactured by Sakura Seisakusho), the same honeycomb mixer, the same Imstat mixer (manufactured by Tatsumi Kogyo), the Shimazaki pipe mixer (manufactured by Koritsu Kogyo), the same high mixer (manufactured by Toray Industries), etc. I can do it. A plurality of these mixer elements are usually installed in the flow direction of the mixed fluid in the pipe. The perforated plate used in the present invention is a plate having independent pores and having an arbitrary cross-sectional area and thickness, and is inserted into a pipe or integrated with the pipe or integrated with a static fluid mixer element. installed as a thing. The pores referred to here are channels through which fluid passes, regardless of the manufacturing method, and the plate shape may have irregularities on the plate surface. Further, for example, a shell-and-tube type heat exchanger in which fine holes are connected by thin tubes can also be used as the perforated plate. The pore shape in the perforated plate is arbitrary, but the ratio of the sum of all pore cross-sectional areas to the plate cross-sectional area (hereinafter abbreviated as pore size ratio) must be 0.55 or less, and one pore It is necessary that the ratio of the cross-sectional area to the sum of all pore cross-sectional areas (hereinafter abbreviated as distribution ratio) is 0.005 or less. The optimum opening ratio is in the range of 0.1 to 0.35, and when it is larger than 0.55, the pore spacing on the perforated plate becomes small, and when mixing a low viscosity fluid that is incompatible with a high viscosity fluid, etc. Although the particles are once dispersed in the pores of the perforated plate, reaggregation occurs at the outlet of the perforated plate, making it impossible to achieve the mixing improvement effect of the present invention. Moreover, it is more preferable that the distribution ratio is 0.001 or less,
When it is larger than 0.005, the mixing improvement effect becomes poor. The arrangement of the static fluid mixer elements and the perforated plate in the fluid mixing device of the present invention is a series of static fluid mixer elements (hereinafter referred to as static It is necessary to arrange a static fluid mixer block (abbreviated as a fluid mixer block) and one or more perforated plates from the upstream side to the downstream side in a pipe through which fluid flows, and to form a static fluid mixer block-perforated plate. By premixing the mixed fluid in the static fluid mixer block and then supplying it to the perforated plate, the mixing effect in the perforated plate becomes more pronounced. The relationship between the number of static fluid mixer elements per block and premixing performance shows that as the number of elements increases, the improvement in mixing performance is significant up to 10 elements, but beyond that, the improvement in mixing performance is minimal. In order to further increase the premixing performance, it is preferable to repeatedly install the static fluid mixer block-perforated plate combination (hereinafter abbreviated as mixing unit). The number of repetitions of the mixing unit is preferably 1 or more and 3 or less, and a repetition number of 3 is sufficient for premixing all high-viscosity fluids and low-viscosity fluids. In order to make the mixing effect of the present invention remarkable, the static fluid mixer block and the perforated plate are arranged alternately (for example, the static fluid mixer block - perforated plate - static fluid mixer block - perforated plate arrangement). ) is preferable. If the number of static fluid mixer elements per block is three or less, the mixing effect of the perforated plate will not be sufficiently exerted. In the fluid mixing device of the present invention, the above-mentioned 5 points are located downstream of the mixing unit and facing the outlet of the fluid mixing device.
Static fluid mixer elements with a number of <m<30 elements are provided, in which finishing mixing takes place. When the number of elements is 4 or less, the effect of finishing mixing is poor, and on the other hand, even if it exceeds 30, the effect of finishing mixing does not change. It is preferable that the sum of the static fluid mixer elements and the number of finishing mixing zone elements in the mixing unit (hereinafter abbreviated as the total number of installed elements) is 40 or less, and if it exceeds 40, the pressure loss may be excessive. and cannot be put to practical use. A highly viscous fluid suitable for use in the mixing device of the present invention has a viscosity of 5,000 poise or more, preferably 10,000 poise or more at a shear rate of 1 sec ^-1 at the temperature at which the mixing is carried out. It is. Examples of these high viscosity fluids include thermoplastic resins such as polypropylene, polyethylene, polystyrene, impact-resistant polystyrene, AS resin, polyvinyl chloride, polyester, polyimide, polyamide, polyether sulfon, starch syrup, water glass, etc. A solution is given. High viscosity fluid is 5000
In the case of fluids exhibiting a viscosity lower than poise, the effect of installing a perforated plate is not significant, and mixing of fluids exhibiting a viscosity exceeding 300,000 poise is practically not carried out industrially. On the other hand, low viscosity fluids suitable for use in the mixing apparatus of the present invention desirably have a viscosity in the range of 0.2 centipoise to 500 centipoise at the temperature at which the mixing is carried out. Examples of these low viscosity fluids include mineral oil, higher alcohols, higher fatty acids and their solutions, water, methyl, ethyl ketone, acetone, methanol, styrene,
Organic solvents such as ethylbenzene and acrylonitrile, organic peroxides and their solutions such as lauroyl peroxide and benzoyl peroxide,
Examples include antioxidants, antistatic agents, dyes, plasticizers, and solutions thereof. At 20°C or, in the case of a substance that is solid at 20°C, at a temperature 5°C higher than its melting point, it is industrially difficult to mix fluids with a viscosity of 0.2 centipoise or less with the above-mentioned high viscosity fluids, excluding gases. Impossible. Gas and highly viscous fluids are usually mixed using a dynamic mixer or a mixing device that combines a dynamic mixer and a static mixer, and in this case, even if a perforated plate is installed, there is no noticeable No effect was observed. In addition, if the viscosity of the low-viscosity fluid exceeds 500 centipoise, the mixing performance by installing a perforated plate can be improved by increasing the number of static mixer elements so that the pressure loss in the mixing device is the same as when installing a perforated plate. The result is the same as when installing a perforated plate, and the effect of installing a perforated plate cannot be recognized. Next, regarding a perforated plate suitable for implementing the present invention and the arrangement of the static fluid mixer element and the perforated plate,
This will be explained with reference to FIGS. 1 and 2. FIG. 1 shows a perforated plate 1 used in the present invention having pores 2. Each pore 2 is arranged on the perforated plate 1 with an appropriate distance from each other, and the inside of each pore 2 is mixed. Fluid passes through it. The shape of the pores 2 is arbitrary, and any suitable shape can be selected. The thickness of the perforated plate is
Appropriate selection is made taking into consideration pressure, pressure loss, etc. during mixing. FIG. 2 is a schematic diagram showing an example of a mixing device of the present invention in which a perforated plate 1 is installed between static fluid mixer elements 3. The static fluid mixer element 3 and the perforated plate 1 are connected to the tube 4
The fluids to be mixed enter through the inlet section 5, undergo mixing while passing through each static fluid mixer element 3 and the perforated plate 1, and reach the outlet section 6. According to the device of the present invention, the mixing performance is dramatically improved compared to the case of only a static mixer, so the number of static fluid mixer elements can be significantly reduced, and especially for mixing highly viscous substances. In this way, it is possible to solve the conventional disadvantages of the device and operational limitations due to an increase in the number of static fluid mixer elements and an increase in pressure loss within the device. This point is so remarkable that it could not be predicted from the conventional technology, and is an epoch-making feature that dramatically expands the applications of static mixers that contribute to energy savings. Next, the present invention will be specifically explained with reference to Examples. Examples 1 to 4, Comparative Examples 1 to 5 A perforated plate (diameter
A fluid mixing device was used in which static mixing elements (trade name: SMX type) manufactured by Sulzer were arranged in various ways according to the arrangement format shown in Table 2. Then, polystyrene resin and mineral oil were mixed and dissolved. The mixing device was equipped with a jacket and maintained at 220°C using a heating medium. This polystyrene resin has a viscosity of 50,000 poise at 220°C and a shear rate of 1 sec ^-1 .
Maintain at 220℃ and transfer to mixing device using gear pump10
It was supplied at a rate of Kg/h. On the other hand, mineral oil at 20℃
It was 100 centipoise, and was injected into the mixing device at a rate of 0.2 kg/h using a metering pump through a thin tube introduced into the inlet of the mixing device. The degree of mixing and dissolution is determined by stretching 5 kg of the mixture of polystyrene resin and mineral oil taken out from the mixing device outlet into a thin plate with a thickness of 1 mm, and observing it using an optical microscope at 100x magnification. of mineral oil droplets. In addition, the difference in the readings of the remote pressure gauges installed at the inlet and outlet of the mixing device was taken as the pressure loss inside the mixing device. These results are shown in Table 2.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is an example of a plan view of a perforated plate arranged in a mixing device of the present invention, and FIG. 2 is a schematic diagram showing a cross section of a mixing device formed by disposing a static fluid mixer element and a perforated plate. This is an example. DESCRIPTION OF SYMBOLS 1... Perforated plate, 2... Pore, 3... Static fluid mixer element, 4... Pipe, 5... Mixing device inlet part,
6...Mixing device outlet section.

Claims (1)

[Claims] 1. A series of stationary fluid mixer elements having a static fluid mixer element and a perforated plate in a pipe through which a fluid flows, and in which the number (m) of static fluid mixer elements is 4≦m≦10. A mixing unit formed by sequentially arranging a fluid mixer element and a perforated plate in which the ratio of the sum of all pore cross-sectional areas to the plate cross-sectional area (opening ratio) is 0.55 or less along the fluid flow direction, A series of static fluid mixer elements arranged such that the number of mixing units is 1 or more and 3 or less and the number of static fluid mixer elements (m') is 5≦m'≦30 is connected to the fluid in the pipe. A fluid mixing device arranged facing the outlet, characterized in that the ratio (distribution ratio) between the cross-sectional area of one hole and the sum of the cross-sectional areas of all the holes in the perforated plate is 0.005 or less. Mixing equipment. 2. The fluid mixing device according to claim 1, wherein the total number of the static fluid mixer elements is 40 or less.