CN220026989U - Reaction equipment capable of being used for high-viscosity system - Google Patents

Abstract

The reaction equipment comprises a feed inlet, a discharge outlet, a reaction equipment shell and a reactor, wherein a bracket and the reactor are arranged in the reaction equipment, the reactor is positioned between the feed inlet and the discharge outlet, and a thermometer is arranged in the central area of the reactor to better control the reaction temperature; an auxiliary stirrer is arranged in the area, close to the center of the circle, of the reactor to enhance the stirring effect. The reaction equipment can timely bring materials from the bottom of the reaction equipment to the top of the reaction container, timely take away heat, fully react the materials in the two reactors, uniformly and thoroughly react, have high efficiency and short time, reduce equipment detection and maintenance times, reduce production cost and obviously improve the quality of products.

Description

Reaction equipment capable of being used for high-viscosity system

Technical Field

The utility model belongs to the field of chemical industry, and relates to reaction equipment, in particular to reaction equipment used in a high-viscosity system.

Background

The vinegar tablet production process adopts the traditional low-temperature acetification process, and the process has higher energy consumption and material consumption. The low-temperature acetification process adopts a vertical reactor. The stirrer of the vertical stirrer mainly comprises a motor, a speed reducer, a stirring shaft, paddles and the like. Stirring blades have various forms, but no matter what type of blade is adopted, the shaft power consumption of the stirring machine generates two parts of effects when the stirring machine is operated, one part is the liquid discharge amount generated by the blade, and the other part is the pressure head generated by the blade. The pressure head generated by the blade can be divided into two parts, namely a static pressure head and a shearing force; when the stirrer blade is operated, the static pressure head must be overcome, and the shearing force causes the materials to be dispersed and mixed. Therefore, all paddles can be classified into three basic types, namely, a flow type, a head type and a shear type, depending on the amount of liquid discharge generated by the paddles, overcoming the magnitude of static head and the capability of generating shear force.

Another common reactor is an internal anchored reactor. Typically, a slow speed stirrer is often used for the processes of medium-high viscosity liquid mixing, heat transfer reaction and the like. Specifically, the method comprises anchor frame (MKS), anchor belt type (MDS), square frame type (FKS), square grid type (FSS), plate frame type (BKS) and the like. The anchor frame can obtain large shearing force along the wall surface when rotating at low speed, can prevent sedimentation and wall surface adhesion, and the bottom shape is attached to the elliptical tank and the bottom bearing in the middle. The anchor belt is a combination of a screw belt and a frame, and combines the functions of the screw belt and the frame stirrer. Fang Kuangshi and square grid type are simple in shape and easy to manufacture, and the efficiency is the same as that of a frame type, so that the mixing and dissolving of medium viscosity are more suitable. The plate frame type efficient mixing impeller with wide viscosity range is simple in structure, and the projection area of the impeller on the longitudinal section of the stirring tank occupies a large proportion of the longitudinal section area of the tank. Has high mixing efficiency and large shearing force, and is suitable for solid-liquid suspension, liquid-liquid dispersion, and gas-liquid mass transfer and heat transfer operation for sucking gas from the surface of liquid.

The stirring uniformity of the two types of reaction equipment needs to be improved, and particularly, when the stirring uniformity is applied to the mixing of a high-viscosity heterogeneous system in the production of similar vinegar slices, the mass transfer and heat transfer effects are poor.

In the production of cellulose acetate, cellulose acetylation is the core reaction. The cellulose acetylation reaction is a solid-liquid heterogeneous reaction and rapidly releases heat severely, and the system belongs to a high-viscosity system after the reaction process and the reaction are finished, so that the stirring uniformity of the reaction system and the control of the temperature are two important points of the reaction. The stirring uniformity directly relates to whether the reaction is uniform, thorough and complete; the heat released by the reaction cannot be taken away from the system in time, which is the key to control the temperature.

The conventional heterogeneous reactor is of a vertical main structure and an internal anchor stirrer, the reaction equipment is more applied to a homogeneous reaction system, and for cellulose acetylation, the special reaction stirring uniformity is general, the material feeding amount is required to be reduced, the reaction time is prolonged, and the reaction uniformity is improved thoroughly; poor heat dissipation effect, the system heat is absorbed together by introducing dichloromethane with the temperature of minus 50 ℃ and freezing and crystallizing the reactant through a jacket of a vertical stirrer, and the energy consumption is extremely high.

Disclosure of Invention

The utility model aims to solve the technical problem of providing novel reaction equipment, so that the high-viscosity system is uniformly and thoroughly mixed and reacted with high efficiency; in addition, the temperature in the system can be known in time so as to better control the reaction.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the reaction equipment comprises a feed inlet, a discharge outlet, a reaction equipment shell and a reactor, wherein a bracket and the reactor are arranged in the reaction equipment, the reactor is positioned between the feed inlet and the discharge outlet, and a thermometer is arranged in the central area of the reactor to better control the reaction temperature; an auxiliary stirrer is arranged in the area, close to the center of the circle, of the reactor to enhance the stirring effect.

Further, a first thermometer is arranged in the central area of one side of the reactor, and a second thermometer is arranged in the central area of the other side of the reactor.

Optionally, a first auxiliary stirrer is arranged in a region, close to the center of a circle, of one side of the reactor, and a second auxiliary stirrer is arranged in a region, close to the center of a circle, of the other side of the reactor.

Optionally, the auxiliary stirrer is provided with a stirring end consisting of a plurality of sawtooth-shaped units, and the tips of the sawtooth units face away from the axis.

Optionally, the orthographic projection of the sawtooth unit on a plane is an equilateral triangle.

Optionally, the thermometer is spaced from the hub by a distance of 5-10cm.

Optionally, the distance of the auxiliary stirrer from the shaft center is 30-50cm.

In one embodiment, the reaction equipment of the high-viscosity system comprises a feed inlet, a discharge outlet, a reaction equipment shell and a reactor. A bracket and at least two reactors are arranged in the reaction equipment, the two reactors are positioned between the feed inlet and the discharge outlet, and the bracket is fixed on the kettle wall of the reaction equipment; at least two central roll shafts are fixed on the support, the first central roll shaft and the second central roll shaft are respectively positioned at the symmetrical centers of the first reactor and the second reactor, the plane of the reactor is vertical to the direction of the central roll shaft, and the reactors rotate around the central roll shaft but do not contact or collide with each other; the distance between the feed inlet and the discharge outlet is larger than the diameter of any one reactor, and a gas phase space of the reaction equipment is reserved between the reactor and the feed inlet.

Optionally, each reactor is in a central symmetry shape, the first reactor and the second reactor are not completely separated, and the distance between the first central roller shaft and the second central roller shaft is smaller than the sum of the radiuses of the first reactor and the second reactor; the first central roll shaft and the second central roll shaft are perpendicular to the connecting line from the feed inlet to the discharge outlet; at least one stirring sheet is arranged in each reactor, and the stirring sheets form a reactor plane and rotate along with the central roll shaft; each stirring plate is provided with at least one wedge-shaped or trapezoid stirring plate; the stirring piece is at a fixed angle.

Alternatively, each reactor is identical in shape and is centrally symmetrical, the two reactors are not completely separated, and the distance between the central roll shafts is smaller than the distance from the shafts to the edges of the reactors.

Optionally, at least one stirring piece is arranged in each reactor, each stirring piece is respectively provided with two wedge-shaped stirring pieces, and the stirring pieces are closely adjacent to the kettle wall of the reaction equipment, so that the stirring pieces extrude or scrape the mixed material adhered to the kettle wall to mix with other materials. The exact meaning of "immediately adjacent" is: the gap between the stirring blades is 0.1mm-1mm under the condition of not influencing the movement of the stirring blades relative to the kettle wall. Too large space has limited scraping effect, and is not beneficial to stirring and heat transfer; the thermal expansion and contraction in the reaction process with too small interval can possibly cause the stirring sheet to collide with the wall to damage equipment.

Optionally, the reactor profile is selected from, but not limited to: cylindrical, elliptic cylindrical, triangular, square, polygonal, or rounded triangular, square, polygonal, etc. In general, the two reactors are identical in appearance and relatively simple to manufacture. Alternatively, the reactor central roll axis is perpendicular to the reactor plane. In general, the reactor uses the central roll shaft as a symmetrical center, the angle between the reactor and the central roll shaft is fixed, and more modes that the central roll shaft is perpendicular to the plane of the reactor are adopted in practice, so that the space is saved relatively. The difference in the angle of the reactor plane to the central roll axis results in different forces.

Alternatively, the two reactors have an intersection of 30-110 degrees with each other. The intersection refers to an included angle of a connecting line formed by the axis of the central roll shaft and the intersection point of the circular contour lines of the two reactors.

Alternatively, the reactors are two cylindrical reactors, a single cylindrical reactor having a length L, a single cylindrical diameter R, a single stirring vane length L1, a headspace height H in the range of 1.4-1.8, and a L/L1 in the range of 1.3-1.7. Alternatively, the two reactors have a certain cross area, and when the mixture enters the cross area, the two reactors are combined to increase the collision reaction probability of the components. For example, when both reactors are cylindrical, the angle of the intersection region is in the range of 30-110 degrees. The term "30-110 degrees" refers to the included angle of the connecting line formed by the intersection point of the axis of the central roll shaft and the circular contour lines of the two reactors.

Alternatively, in one embodiment employing two cylindrical reactors, the two cylindrical reactors are of equal radius.

The distance between the two central rollers is 10% -70% of the sum of the radius of the two reactors.

Optionally, the extension of the reactor edge extends in a direction closer to the central roll axis or further from the central roll axis. The reactor edge may extend in the direction of the other reactor or both reactor edges may extend in the direction of the other reactor. When the edge of the reactor extends towards the other reactor, the edges of the two reactors are gradually close to each other and gather together, and when the reaction system or the mixture is stirred, the part thrown out by the centrifugal force is slightly less, and part of the mixture falls back into the stirring range of the reactor, so that the mixture can be stirred more uniformly.

Alternatively, the extending manner may be a step type or a curve type, a groove type, or the like. The extension of the reactor edge towards the other reactor may be streamlined. When the step type or groove type is adopted, the reaction system or the mixture is stirred, and part of the mixture falls back into the stirring range of the reactor due to the gathering shape of the edge, so that the mixture can be stirred more uniformly. When streamline is adopted, the mixture is not easy to remain or adhere to the reactor, so that the frequency of cleaning dirt and overhauling is reduced.

Alternatively, the direction of rotation of the reactors is different or the same. When the rotation directions of the reactors are the same, the mixed materials in the reaction system are influenced by the rotation of the two reactors, and the mixture components are continuously stirred to promote the reaction. When the rotation directions of the reactors are different, the mixed materials are subjected to different directional acting forces of the two reactors, the collision and impact among the two reactors are increased, the reaction efficiency can be improved, and the materials can be improved.

For example, the present utility model exploits the simultaneous, anisotropic cylindrical reactors, which have an intersection of 30-90 degrees with each other and sufficient gas phase space in the upper part of the two cylindrical reactors, each having at least one stirring blade. Preferably, each stirring piece is provided with two stirring pieces similar to a wedge structure and clung to the similar cylindrical kettle wall, so that materials on the kettle wall can be scraped off conveniently. The two stirring sheets are in a 90-degree angle, the rotating speeds are the same, and the rotating directions are different. The stirring type can timely bring materials from the bottom of the reaction equipment to the top of the reaction equipment, and meanwhile, the top has enough gas phase space, so that heat can be timely taken away through vacuumizing flash evaporation. Because the two circles have 90-degree intersection, the materials have the opportunity to fully react in the two cylindrical reactors, and the reaction is uniform and thorough, the efficiency is high, and the time is short.

To ensure uniform stirring and thorough reaction, for simplicity of illustration, a single cylindrical reactor length L, a single cylindrical diameter R, a single stirring vane length L1, a headspace height H, L/R should be in the range of 1.4-1.8, and L/L1 should be in the range of 1.3-1.7 is defined. The angle of the two circular interdigitated areas is in the range of 30-110 degrees and the R/H should be in the range of 1.4-1.8. The stirring phase difference of the two stirring sheets is in the range of 60-120 degrees.

The motor drives the first central roll shaft and the second central roll shaft to rotate so as to drive the respective bracket and the stirring piece to rotate; at least one reactor is arranged on both sides of the other reactor.

The reaction equipment of the high-viscosity system can be used for high-efficiency mixing reaction of the high-viscosity system, and can promote the uniform stirring or full reaction of the high-viscosity heterogeneous system.

Optionally, the reaction device is used for cellulose derivatization reaction. In the cellulose derivatization reaction, reactants are in a viscous slurry shape, so that uneven stirring is easy, and particularly, the materials at the bottom prevent the cellulose reaction system from being too viscous or blocked.

Optionally, the reaction equipment is used for cellulose production, and the using method comprises the following steps:

(a) Starting the reaction equipment to stabilize the stirring of the reactor;

(b) Opening a feed inlet to enable the reaction mixture to enter the reaction equipment and fully mix under the drive of a stirring sheet;

(c) And opening the discharge hole to enable the mixed reaction product to enter the next working procedure through the discharge hole.

Optionally, the reaction device is used for cellulose production, and comprises the following steps:

(1) Adding pure acetic acid into the ground acetified wood pulp cellulose, and stirring at room temperature for pretreatment to enhance the reactivity;

(2) Adding the mixture of acetic anhydride and acetic acid into the reaction equipment after preliminary precooling;

(3) Adding catalyst concentrated sulfuric acid into the wood pulp reaction equipment after pretreatment, heating the system after the reaction starts to cause the temperature of the system to rise, starting a vacuum pump, and flash evaporating and volatilizing acetic acid in the reaction system;

(4) After the acetification reaction is finished, adding hot water and magnesium acetate into the acetification product, and recovering acetic acid in the hydrolysate; and (3) pumping out the recovered acetic acid aqueous solution, adding an ion-free water product, separating out vinegar slices, and washing the vinegar slices until the washing water is neutral.

In a preferred embodiment of the utility model, the specific application method is as follows:

(1) Adding 80kg of pure acetic acid with the concentration of more than 99% into 200kg of ground acetified wood pulp cellulose, and stirring at room temperature for pretreatment for 30min to enhance the reactivity.

(2) 1130kg of a mixture of acetic anhydride and acetic acid (mixed acid) was cooled to 4.5℃in a reaction apparatus, wherein acetic anhydride was 45% by mass.

(3) The pretreated wood pulp is added into the cooled mixed acid, then 6kg of catalyst sulfuric acid is added, the amount of sulfuric acid is 3% of the mass of cellulose, the pH of the system is-0.30, and the reaction starts. After the reaction starts, the system releases heat to cause the temperature of the system to rise to 60 ℃ within 30min, a vacuum pump is started to vacuumize while the temperature rises, the absolute pressure is 5.5kPa, and acetic acid in the reaction system is flash evaporated. After the temperature reaches 60 ℃, stopping a vacuum pump, continuing the reaction for 13min, and ending the acetification reaction, wherein 48kg of flash evaporation volatilized acetic acid is collected in the process, and the concentration of the obtained acetic acid solution is 95.8wt%.

(4) 76kg of hot water was added to the acetified product, the hot water accounting for 5.2% of the acetified product by mass, heating was started from about 50 ℃, heating was started to 95 ℃ in about 30 minutes, maintaining 95 ℃ for about 40 minutes, then 40kg of a magnesium acetate solution was added, the mass ratio of the magnesium acetate solution to the acetified product was 2.8%, maintaining 95 ℃ for about 20 minutes was continued, and then the reaction was ended. Recovering acetic acid from the hydrolysate under reduced pressure by using a vacuum pump, wherein the absolute pressure is 12kPa, pumping for 14min, and recovering about 5.6kg of acetic acid aqueous solution, wherein the concentration of the acetic acid solution is 65%; adding a large amount of deionized water product vinegar slices into the reaction products after the pumping is finished to start precipitation, continuously washing vinegar slice particles with deionized water, and detecting the washing water until the washing water is neutral; drying the product vinegar tablet at 120 ℃ for 8 hours, and detecting.

(5) The obtained product had a filter plug value of 45, an acetylation value of 55.0%, an intrinsic viscosity of 1.52, a whiteness of 2.7,5 μm particle number 6100.

Optionally, when the reaction device is constructed, the upper parts of the two reactors are provided with enough gas phase spaces, each reactor is provided with a stirring sheet, and each reactor is respectively provided with two stirring sheets similar to a wedge structure and closely attached to the kettle wall of the reaction device, so that materials on the kettle wall can be scraped off conveniently; the reactor is in a stirring form, so that materials can be timely brought to the top of the reaction equipment from the bottom of the reaction equipment, and meanwhile, the top has enough gas phase space, and heat can be timely taken away through vacuumizing flash evaporation.

Optionally, the two stirring sheets are in an angle of 30-90 degrees, the rotating speeds are the same, and the rotating directions are different; the materials are fully reacted in the two reactors, the reaction is uniform and thorough, the efficiency is high, and the time is short.

The reaction equipment is suitable for the reaction process of a high-viscosity reaction system. The reactor and the stirring blade thereof arranged aiming at a heterogeneous reaction system, particularly a high-viscosity heterogeneous system with larger viscosity, can improve the stirring frequency in the reaction, tear the viscous reactant, increase the mixing and stirring of each component and the possibility of mutual reaction, promote the release of heat in the reaction, facilitate the smooth proceeding of the reaction, reduce the damage to the machine equipment, reduce the frequency of maintenance and detection and promote the improvement of productivity.

Optionally, the viscosity of the high viscosity reaction system is 5000-15000 centipoise. The reaction equipment is used for the cellulose reaction process of vinegar tablet production, can improve the reaction efficiency, and also remarkably improves the quality of products, and the obtained products have improved filtration blocking value, increased acetylation value and increased whiteness.

Due to the adoption of the technical scheme, the beneficial effects obtained by the utility model include:

the high-efficiency mixing reaction equipment for the high-viscosity system can timely bring materials from the bottom of the reaction equipment to the top of the reaction equipment, and meanwhile, the top has enough gas phase space, so that heat can be timely taken away through vacuumizing flash evaporation. For the reaction in which the mixed material is in a viscous state, the material is easy to stir unevenly, and particularly, the material at the bottom is deposited at the lower part of the mixing reaction device and cannot be effectively stirred. According to the utility model, the reactors have intersection, the stirring probability of materials in the intersection area of two reactors is increased by 1 time, and the stirring effect and the heat dissipation effect are obviously improved. The difference of the rotating direction and the rotating speed between every two reactors produces pulling and shearing force on viscous materials, the materials can fully react in the two reactors, the reaction is uniform and thorough, the efficiency is high, the time is short, the energy consumption is low, and the requirements of double control and double carbon in future countries are met. The reaction equipment is applied to the derivatization reaction process of the cellulose acetate flake, can timely take away the heat released by the reaction from the system, greatly reduces the energy consumption, reduces the equipment detection and maintenance times, and reduces the production cost.

Drawings

FIG. 1 is a schematic axial structural view of an embodiment of a high-efficiency mixing reaction apparatus usable in a high-viscosity system according to the present utility model.

FIG. 2 is a radial cross-sectional view of an embodiment of the reaction apparatus of the present utility model.

Fig. 3 is a top view of a first reactor core component of an embodiment of the utility model.

FIG. 4 is a front view of the core components and stirring sheet of the reaction apparatus of the present utility model.

FIG. 5 is a side view of the core components and stirring plate of the reaction apparatus shown in FIG. 4.

The icons in the drawings are: 1-a feed inlet, 2-a first discharge outlet, 3-a second discharge outlet, 4-a reaction equipment shell, 5-a first reactor, 6-a reaction equipment gas phase space, 7-a second reactor, 81-a first support, 82-a second support, 9-a kettle wall, 51-a first central roll shaft, 521-a first stirring sheet and 522-a second stirring sheet; 71-second central roll shaft, 721-third stirring blade, 722-fourth stirring blade. A first thermometer 111, a second thermometer 112; a first auxiliary stirrer 101 and a second auxiliary stirrer 102.

Detailed Description

The utility model is further described below with reference to the drawings and examples.

The definition or test method of the parameter indicators mentioned in the comparative examples and examples is as follows:

filter plug value: dissolving vinegar tablet in acetone to obtain 9.5% concentration solution, and filtering the slurry with filter paper under 1.5 atm, according to the filtering amount;

the acetylation value% = 6000 x substitution/(162+42 x substitution), wherein the substitution is obtained according to acid-base titration;

intrinsic viscosity: dissolving vinegar tablet in acetone to obtain 0.25% concentration solution, and testing with Ubbelohde viscometer;

whiteness: and testing the color b value by using a spectrocolorimeter.

Comparative example 1

The most widely used vertical agitators are currently available. The conventional cellulose production process includes:

(1) 80kg of pure acetic acid with the concentration of more than 99% is added into 200kg of ground acetified cellulose, and the mixture is stirred and pretreated for 40min at room temperature to enhance the reactivity.

(2) 1100kg of a mixture of acetic anhydride and acetic acid (mixed acid) was cooled in the reaction apparatus to-18℃with acetic anhydride accounting for 45%.

(3) The pretreated wood pulp is added into the cooled mixed acid, then 26kg of catalyst sulfuric acid is added, the dosage of the sulfuric acid is 13% of the mass of cellulose, and the reaction is started. The exothermic heat of the system after the start of the reaction caused the temperature of the system to rise to 46 ℃ within 30min, and the vertical reactor jacket freezing medium circulation was required to be started while the temperature was rising so as to take away the heat released by the reaction. After reaching the peak temperature, the reaction is continued for 23min, and then the acetification reaction is finished.

(4) 91kg of hot water is added into the acetification product, the hot water accounts for 4.6% of the mass ratio of the acetification product, heating is started from about 40 ℃, the temperature is raised to 82 ℃ within about 48 minutes, the temperature is maintained at 82 ℃ for about 100 minutes, 90kg of magnesium acetate solution is added, the mass ratio of the magnesium acetate solution to the acetification product is 6.0%, and the reaction is finished after stirring for 5 minutes. Adding a large amount of deionized water into the reaction product to start precipitation, continuously washing vinegar tablet particles with deionized water, and detecting washing water until the washing water is neutral; the resultant vinegar tablet was dried at 120℃for 8 hours.

(5) The resulting product had a filter plug value of 35, an acetylation value of 55.7%, an intrinsic viscosity of 1.59, and a whiteness of 9.9.

Referring to fig. 1 for a structure of an embodiment of the present utility model, a reaction apparatus of a high viscosity system is provided with at least two reactors, wherein the two reactors are located between a feed inlet (1) and a discharge outlet (2), and a first bracket (81) and a second bracket (82) are respectively fixed at two ends of a kettle of the two reaction apparatus; the first central roll shaft (51) and the second central roll shaft (71) are respectively positioned at the symmetrical centers of the first reactor (5) and the second reactor (7), the plane of the reactor is vertical to the direction of the central roll shaft, and the reactors rotate around the central roll shaft but do not contact or collide with each other; the distance between the feed inlet (1) and the first discharge outlet (2) and the distance between the feed inlet and the second discharge outlet (3) are larger than the diameter of any one reactor, and a gas phase space of reaction equipment is reserved between the reactor and the feed inlet (1);

each reactor is in a central symmetry shape, the first reactor (5) and the second reactor (7) are not completely separated, and the distance between the first central roll shaft (51) and the second central roll shaft (71) is smaller than the sum of the radiuses of the first reactor (5) and the second reactor (7); the first central roll shaft (51) and the second central roll shaft (71) are perpendicular to the connecting line from the feed inlet (1) to the discharge outlet (2);

at least one stirring piece is arranged in each reactor, and the stirring piece is connected with the first central roll shaft and the second central roll shaft through the first support and the second support respectively and rotates along with the central roll shafts.

The two reactors are the same in size or shape, the peripheral outline of the two reactors is cylindrical, the two reactors are mutually intersected at an angle of 90 degrees, the upper parts of the two cylindrical reactors are provided with enough gas phase spaces, each reactor is provided with a support, and each support is respectively provided with two stirring sheets similar to a wedge structure and closely attached to the kettle wall of the cylindrical reaction equipment, so that materials on the kettle wall can be scraped off conveniently. The two brackets are at an angle of 60 degrees, the rotating speeds are the same, and the rotating directions are different. The length of the single cylindrical reactor is L. The reaction system enters the reaction equipment from the feed inlet, and is discharged from the discharge outlet after mixed reaction.

In fig. 2, L represents the length of the cylindrical reactor.

In FIG. 3, the reactor has a single stirring vane length L1.

Example 1

The synchronous heterogeneous reaction equipment comprises a first reactor 5 and a second reactor 7, wherein the outer outlines of the first reactor 5 and the second reactor 7 are cylindrical and are mutually intersected, as shown in fig. 1, circles respectively representing the first reactor 5 and the second reactor 7 are provided with two intersecting points, and an included angle theta is formed between the axle center 71 of a second central roll shaft and a connecting line of the two intersecting points, and in the embodiment, the theta is a 90-degree angle.

As shown in fig. 3, the first bracket 81 is fixed to the first center roller shaft 51, and the first center roller shaft 51 is fixed to both ends of the apparatus. The first bracket 81 is made of common stainless steel material, and plays a role in fixing connection between the roll shaft and the stirring blade, and the fixing mode can be welding, bolt fixing and the like. The two ends of the first bracket 81 are respectively connected with the first stirring blade 521 and the second stirring blade 522, the first roller shaft 51 drives the first bracket 81 to rotate, and the first bracket 81 drives the first stirring blade 521 and the second stirring blade 522 to rotate.

The first reactor 5 and the second reactor 7 have the same structure, the upper parts of the first reactor 5 and the second reactor 7 are respectively provided with a sufficient gas phase space 6, the center of the first reactor 5 is provided with a first central roll shaft 51, the first central roll shaft 51 is provided with a first bracket 81, the first bracket 81 is provided with two first stirring sheets 521 and second stirring sheets 522 which are symmetrical about the center of the first central roll shaft 51 and have the same structure, the first stirring sheets 521 and the second stirring sheets 522 are similar to wedge structures, the surfaces of the first stirring sheets 521 and the second stirring sheets 522 are smooth, and the cross section is detailed in the accompanying drawings. The outer edges of the first stirring blade 521 and the second stirring blade 522 are closely adjacent to the kettle wall 9, and the intervals thereof are 0.1mm-1mm. Too large space has limited scraping effect, and is not beneficial to stirring and heat transfer; the thermal expansion and contraction in the reaction process with too small interval can possibly cause the stirring sheet to collide with the wall to damage equipment. On the cylindrical kettle wall 9, the materials on the kettle wall 9 are convenient to scrape off.

Similarly, a second center roller 71 is provided at the center of the second reactor 7, and a second bracket 82 is mounted on the second center roller 71.

The second bracket 82 is provided with two third stirring sheets 721 and 722 which are symmetrical about the center of the second center roller shaft 71 and have the same structure, and the third stirring sheets 721 and 722 are similar to wedge structures.

In order to avoid collision of the stirring sheets of the first reactor 5 and the second reactor 7 and obtain better stirring effect, the first support 81 and the second support 82 respectively form an angle of 90 degrees between the central lines passing through the stirring axes of the first support and the second support, so that the first stirring sheet 521, the third stirring sheet 721, the second stirring sheet 522 and the fourth stirring sheet 722 sequentially pass through an intersection area of the first reactor 5 and the second reactor 7 at equal intervals (a quarter period) to stir reactants in the intersection area.

The rotation speeds of the first reactor 5 and the second reactor 7 are the same, and the rotation directions are different. As shown in fig. 1, the first reactor 5 rotates clockwise and the second reactor 7 rotates counterclockwise.

For better control of the reaction temperature, a first thermometer 111 is provided in the left central region of the reactor and a second thermometer 112 is provided in the right central region of the reactor.

Further, in order to enhance the stirring effect, a first auxiliary stirrer 101 is provided at one end of the reactor near the center of the circle, and a second auxiliary stirrer 102 is provided at the other end of the reactor near the center of the circle.

The thermometer and the auxiliary stirrer are welded at both ends of the cylindrical reactor.

The saw teeth of the first auxiliary stirrer 101 and the second auxiliary stirrer 102 are equilateral triangles, the side length is 5-15cm, the whole length of the auxiliary stirrers is 40-60cm, 4 auxiliary stirrers are arranged on two circles, so that the deep crushing of reaction materials is facilitated, the reaction uniformity is improved, the quick heat dissipation is facilitated, the saw teeth face in the direction away from the circle center, the circle center is on a horizontal line, and the distance from the circle center is 30-50cm; the distance between the thermometer and the center of the circle is 5-10cm, the closer the thermometer is to the center of the circle, the closer the thermometer is to the actual temperature of the material, and the two circles are provided with two temperature measuring points, and the two circles are provided with 4 temperature measuring points, so that the reaction temperature can be controlled accurately.

The stirring type can timely bring materials from the bottom of the reaction equipment to the gas-phase space 6 at the top of the reaction equipment, and meanwhile, the top of the stirring type has enough gas-phase space, so that heat can be timely taken away through vacuumizing flash evaporation. Because the first reactor 5 and the second reactor 7 have 90-degree intersection, materials can be fully reacted in the two cylindrical reactors 5 and 7, and the reaction is uniform and thorough, the efficiency is high, and the time is short; the stirring speed of the materials in the intersection area of the two reactors is increased by 1 time, so that the reaction effect is obviously improved.

To ensure uniform stirring and thorough reaction, for simplicity of illustration, a single cylindrical reactor length L of 240cm, a single cylindrical diameter R of 150cm, a single stirring vane length L1 of 160cm, a top gas phase space height H of 94cm, L/R of 1.6 and L/L1 of 1.5 was defined. The angular extent of the two circular interdigitated areas is 90 degrees and R/H is 1.6. The stirring phase difference of the two brackets is 90 degrees. The resulting product had a filter plug value of 70, an acetylation value of 55.1%, an intrinsic viscosity of 1.50, and a whiteness of 2.2,5 μm particle count of 3700.

Example 2

A synchronous anisotropic reaction device is characterized in that two cylindrical reactors are mutually intersected at an angle of 60 degrees, the upper parts of the two cylindrical reactors are provided with enough gas phase spaces, each reactor is provided with a support, and each support is respectively provided with two stirring sheets similar to a wedge structure and clung to the wall of a similar cylindrical kettle so as to be convenient for scraping materials on the wall of the kettle. The two brackets are at an angle of 60 degrees, the rotating speeds are the same, and the rotating directions are different. The stirring type can timely bring materials from the bottom of the reaction equipment to the top of the reaction equipment, and meanwhile, the top has enough gas phase space, so that heat can be timely taken away through vacuumizing flash evaporation.

The length L of the single cylindrical reactor was 240cm, the diameter R of the single cylinder was 171cm, the length L1 of the single stirring blade was 185cm, the height H of the headspace was 122cm, L/R was 1.4, and L/L1 was 1.3. The angle of the two circular interdigitated areas is 100 degrees and R/H is 1.4. The stirring phase difference of the two brackets is 100 degrees. The resulting product had a filter plug value of 90, an acetylation value of 55.3%, an intrinsic viscosity of 1.50, and a whiteness of 2.2,5 μm particle count of 3500.

Example 3

A synchronous heterogeneous reaction device is characterized in that two cylindrical reactors are mutually intersected at an angle of 90 degrees, the upper parts of the two cylindrical reactors are provided with enough gas phase spaces, each reactor is provided with a support, and each support is respectively provided with two stirring sheets similar to a wedge structure and closely attached to the cylindrical kettle wall, so that materials on the kettle wall can be scraped off conveniently. The two brackets are at an angle of 90 degrees, the rotating speeds are the same, and the rotating directions are different. The stirring type can timely bring materials from the bottom of the reaction equipment to the top of the reaction equipment, and meanwhile, the top has enough gas phase space, so that heat can be timely taken away through vacuumizing flash evaporation. Because the two circles have 90-degree intersection, materials can be fully reacted in the two cylindrical reactors, and the reaction is uniform and thorough, the efficiency is high, and the time is short.

The length L of the single cylindrical reactor was 240cm, the reactor diameter R was 133cm, the length L1 of the single stirring vane was 141cm, the height H of the headspace was 74cm, L/R was 1.8, and L/L1 was 1.7. The angle of the two circular interdigitated areas was 70 degrees and R/H was 1.8. The stirring phase difference of the two brackets is 120 degrees. The resulting product had a filter plug value of 90, an acetylation value of 55.2%, an intrinsic viscosity of 1.51, and a whiteness of 3.9,5 μm particle count of 5600.

Example 4

The synchronous homodromous reaction equipment comprises two cylindrical reactors, wherein the two cylindrical reactors are mutually intersected at an angle of 90 degrees, the upper parts of the two cylindrical reactors are provided with enough gas phase spaces, each reactor is provided with a support, and each support is respectively provided with two stirring sheets similar to a wedge structure and clung to the cylindrical kettle wall, so that materials on the kettle wall are scraped off conveniently. The two brackets are at an angle of 90 degrees, the rotating speeds are the same, and the rotating directions are different. The stirring type can timely bring materials from the bottom of the reaction equipment to the top of the reaction equipment, and meanwhile, the top has enough gas phase space, so that heat can be timely taken away through vacuumizing flash evaporation. Because the two circles have 90-degree intersection, the materials can be fully reacted in the two cylindrical reaction devices, and the reaction is uniform and thorough, the efficiency is high, and the time is short.

The length L of the single cylindrical reactor was 240cm, the reactor diameter R was 150cm, the length L1 of the single stirring vane was 160cm, the height H of the headspace was 94cm, L/R was 1.6, and L/L1 was 1.5. The angle of the two circular interdigitated areas is 90 degrees and R/H is 1.6. The stirring phase difference range of the two brackets is 90 degrees. The resulting product had a filter plug value of 40, an acetylation value of 55.5%, an intrinsic viscosity of 1.49, a whiteness of 5.5,2,5 μm particle count 7200.

Example 5

The novel reaction equipment is used in the vinegar slice production process, can fully react the mixture in the reaction equipment, and has the advantages of uniform and thorough reaction, high efficiency and short time. The reaction product can better reach the expected reaction efficiency, and the influence of the product impurities on the subsequent reaction and instruments and equipment is reduced. Heat can be taken away in time in the reaction process, damage to machine equipment is reduced, and energy consumption is reduced.

Taking the synchronous heterogeneous reaction device of example 1 as an example, when in use, the reaction device is started first, and after preheating and reaching a stable operation state, the feed inlet is opened to allow the mixture of acetic anhydride and acetic acid to enter the reaction device. The two circular reactors have an intersection of 90 degrees with each other and the upper parts of the two cylindrical reactors have sufficient gas phase space to provide sufficient space for stirring of the mixture. Each reactor is provided with a bracket, and each bracket is respectively provided with two stirring sheets similar to a wedge structure and clings to the cylindrical kettle wall. The mixture of acetic anhydride and acetic acid has high viscosity, is easy to adhere to the kettle wall, reduces the probability of reaction and affects the stirring of other materials. The two supports are in a 90-degree angle, the rotating speeds are the same, the rotating directions are different, and the materials collide with each other under the driving of the supports, so that the stirring and reaction efficiency is improved.

The stirring type can timely bring materials from the bottom of the reaction equipment to the top of the reaction equipment, and meanwhile, the top has enough gas phase space, so that heat can be timely taken away through vacuumizing flash evaporation. Because the two circles have 90-degree intersection, materials can be fully reacted in the two cylindrical reactors, and the reaction is uniform and thorough, the efficiency is high, and the time is short. The mixture is reacted for a preset time, fully reacted and then enters the next working procedure through a discharge hole.

As shown in fig. 2 and 3, the two reactors are not closely spaced apart. For example, when the reactors are cylindrical, the distance separating the two reactors may be 10%, 20%, 30%, 40%, 50%, 60%, 70% of the sum of the two reactor radii, etc.

As shown in fig. 3, the extension of the reactor edge in the direction of the other reactor may be streamlined.

The utility model relates to high-efficiency mixing reaction equipment which is used for cellulose derivatization reaction and comprises the following steps:

(1) Adding 8kg of pure acetic acid with the concentration of more than 99% into 200kg of ground acetified wood pulp cellulose, and stirring at room temperature for pretreatment for 30min to enhance the reactivity.

(2) 1130kg of a mixture of acetic anhydride and acetic acid (mixed acid) was cooled to 4.5℃in a reaction apparatus, wherein acetic anhydride was 45% by mass.

(3) The pretreated wood pulp is added into the cooled mixed acid, then 6kg of catalyst sulfuric acid is added, the amount of sulfuric acid is 3% of the mass of cellulose, the pH of the system is-0.30, and the reaction starts. After the reaction starts, the temperature of the system is raised to 57 ℃ within 30min due to the exothermic heat of the system, a vacuum pump is started to vacuumize while the temperature is raised, the absolute pressure is 5.5kPa, and acetic acid in the reaction system is flash evaporated. After the temperature reaches 57 ℃, stopping a vacuum pump, continuing the reaction for 13min, and ending the acetification reaction, wherein 48kg of flash evaporation volatilized acetic acid is collected in the process, and the concentration of the obtained acetic acid solution is 95.8wt%.

(4) 76kg of hot water was added to the acetified product, the hot water accounting for 5.2% of the acetified product by mass, heating was started from about 50 ℃, heating was started to 95 ℃ in about 30 minutes, maintaining 95 ℃ for about 40 minutes, then 40kg of a magnesium acetate solution was added, the mass ratio of the magnesium acetate solution to the acetified product was 2.8%, maintaining 95 ℃ for about 20 minutes was continued, and then the reaction was ended. Recovering acetic acid from the hydrolysate under reduced pressure by using a vacuum pump, wherein the absolute pressure is 12kPa, pumping for 14min, and recovering about 5.6kg of acetic acid aqueous solution, wherein the concentration of the acetic acid solution is 65%; adding a large amount of deionized water product vinegar slices into the reaction products after the pumping is finished to start precipitation, continuously washing vinegar slice particles with deionized water, and detecting the washing water until the washing water is neutral; drying the product vinegar tablet at 120 ℃ for 8 hours, and detecting.

(5) The filter clogging value of the obtained product is increased, the acetylation value is increased, and the whiteness is increased.

Taking the reaction apparatus of example 1 as an example, the obtained product had a filter plug value of 45, an acetylation value of 55.0%, an intrinsic viscosity of 1.52 and a whiteness of 2.7. Compared with the comparative example, the novel acetification device has high reaction efficiency, does not need to cool and crystallize cellulose reaction, greatly saves energy, obviously reduces the consumption of catalyst sulfuric acid and neutralizer magnesium oxide, greatly saves material consumption, and greatly improves indexes such as quality, filtering and blocking value, whiteness and the like of vinegar tablet products.

The foregoing description of the embodiments is provided to facilitate the understanding and appreciation of the utility model by those skilled in the art. It will be apparent to those skilled in the art that various modifications can be readily made to these teachings and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the utility model is not limited to the above description and the description of the embodiments, and those skilled in the art, based on the disclosure of the utility model, should make improvements and modifications without departing from the scope of the utility model.

Claims (17)

1. The utility model provides a reaction equipment that can be used to high viscosity system, includes feed inlet, bin outlet, reaction equipment shell, reactor, sets up support and reactor in the reaction equipment, the reactor is located between feed inlet and the bin outlet, its characterized in that: a thermometer is arranged in the central area of the reactor to better control the reaction temperature; an auxiliary stirrer is arranged in the area, close to the center of the circle, of the reactor to enhance the stirring effect.

2. The reaction apparatus usable in a highly viscous system as claimed in claim 1, wherein: a first thermometer is arranged in the central area of one side of the reactor, and a second thermometer is arranged in the central area of the other side of the reactor.

3. The reaction apparatus usable in a highly viscous system as claimed in claim 1, wherein: a first auxiliary stirrer is arranged in a region, close to the center of the circle, of one side of the reactor, and a second auxiliary stirrer is arranged in a region, close to the center of the circle, of the other side of the reactor.

4. The reaction apparatus usable in a highly viscous system as claimed in claim 1, wherein: the auxiliary stirrer is provided with a stirring end consisting of a plurality of sawtooth-shaped units, and the tips of the sawtooth-shaped units face to the direction far away from the axle center.

5. The reaction apparatus usable in a highly viscous system as claimed in claim 4, wherein: the orthographic projection of the sawtooth-shaped units on a plane is an equilateral triangle.

6. The reaction apparatus usable in a highly viscous system as claimed in claim 1, wherein: the distance between the thermometer and the axle center is 5-10cm.

7. The reaction apparatus usable in a highly viscous system as claimed in claim 1, wherein: the distance between the auxiliary stirrer and the axle center is 30-50cm.

8. The reaction apparatus usable in a highly viscous system as claimed in claim 1, wherein: the reactor is provided with at least two reactors, the two reactors are positioned between a feed inlet (1) and a discharge outlet (2), and a first bracket (81) and a second bracket (82) are respectively fixed at two ends of two reaction equipment kettles; the first central roll shaft (51) and the second central roll shaft (71) are respectively positioned at the symmetrical centers of the first reactor (5) and the second reactor (7), the plane of the reactor is vertical to the direction of the central roll shaft, and the reactors rotate around the central roll shaft but do not contact or collide with each other; the distance between the feed inlet (1) and the first discharge outlet (2) and the distance between the feed inlet and the second discharge outlet (3) are larger than the diameter of any one reactor, and a gas phase space of reaction equipment is reserved between the reactor and the feed inlet (1);

each reactor is in a central symmetry shape, the first reactor (5) and the second reactor (7) are not completely separated, and the distance between the first central roll shaft (51) and the second central roll shaft (71) is smaller than the sum of the radiuses of the first reactor (5) and the second reactor (7); the first central roll shaft (51) and the second central roll shaft (71) are perpendicular to the connecting line from the feed inlet (1) to the discharge outlet (2);

at least one stirring piece is arranged in each reactor, and the stirring piece is connected with the first central roll shaft and the second central roll shaft through the first support and the second support respectively and rotates along with the central roll shafts.

9. The reaction apparatus usable in a highly viscous system as claimed in claim 8, wherein: the cross section of the stirring piece is wedge-shaped or trapezoid.

10. The reaction apparatus usable in a highly viscous system as claimed in claim 8, wherein: the stirring sheets are closely adjacent to the kettle wall of the reaction equipment, and the gap between the stirring sheets and the kettle wall is 0.1mm-1mm under the condition that the movement of the stirring sheets relative to the kettle wall is not influenced.

11. The reaction apparatus usable in a highly viscous system as claimed in claim 8, wherein: the two reactors are the same in size or shape, and the peripheral outline of the two reactors is cylindrical.

12. The reaction apparatus usable in a highly viscous system as claimed in claim 8, wherein: the first reactor (5) and the second reactor (7) mutually have an intersection of an angle of 30-110 degrees, wherein the intersection refers to an included angle of a connecting line formed by the axis of the central roll shaft and the intersection point of the circular contour lines of the two reactors.

13. The reaction apparatus usable in a highly viscous system as claimed in claim 12, wherein: the first reactor (5) and the second reactor (7) are each cylindrical reactors, the length of the single cylindrical reactor is L, the diameter of the single cylinder is R, the length of the single stirring vane is L1, the height H of the headspace is in the range of 1.4-1.8, and L/L1 is in the range of 1.3-1.7, and R/H is in the range of 1.4-1.8.

14. The reaction apparatus usable in a highly viscous system as claimed in claim 13, wherein: the angle of the intersection area of the first reactor (5) and the second reactor (7) is in the range of 30-110 degrees.

15. The reaction apparatus usable in a highly viscous system as claimed in claim 8, wherein: the stirring phase difference of the stirring sheets of the first reactor (5) and the second reactor (7) is in the range of 60-120 degrees.

16. The reaction apparatus usable in a highly viscous system as claimed in claim 8, wherein: the distance between the first center roll shaft (51) and the second center roll shaft (71) is 10% -70% of the sum of the radii of the first reactor (5) and the second reactor (7).

17. The reaction apparatus usable in a highly viscous system as claimed in claim 8, wherein: the first central roll shaft (51) and the second central roll shaft (71) are communicated with a motor, and the motor drives the respective bracket and stirring piece to rotate by driving the first central roll shaft (51) and the second central roll shaft (71) to rotate; the first reactor (5) and the second reactor (7) are respectively arranged at two sides of the bracket (8).