Mixer bladed two-shaft. Double shaft mixer. Calculations of the main parameters

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http://www.allbest.ru

INTRODUCTION

For mixing clay during semi-dry and plastic molding of ceramic products, single-shaft and twin-shaft paddle mixers of continuous and cyclic action are widely used.

Mixers of this group are used both for the preparation of a mixture of several components, and for the preparation of a homogeneous homogeneous mass in dry form or with moisture. Humidification can be done with water or low pressure steam. In the latter case, a higher quality of products is achieved, since the steam heats up the mass and then, condensing, moistens it. The main parameter of paddle mixers is their productivity.

In continuous blade mixers, the blades are fixed on the shaft along a helical line, which ensures simultaneous mixing and movement of the product along the shaft.

To ensure the required quality of mixing of bulk products in a continuous paddle mixer, the optimal mixing time is experimentally established, which should correspond to the time of movement of bulk products in the mixer from the place of loading to the place of unloading. This time can be changed by changing the number of revolutions of the shaft with the blades, as well as the angle of rotation of the blades relative to the shaft. paddle mixer ceramic mixing

The SMK-18 mixer is used in factories manufacturing bricks, tiles and other building ceramics products with initial indicators of clay raw materials:

Humidity 5-20%;

Temperature - not less than + 3 0 С.

1. TECHNICAL DATA

Productivity (at mixture density of 1700 kg/m3)
Working shaft speed
The diameter described by the blades	750 mm
Installed capacity	30 kW
dimensions		5400 mm
		1800 mm
		1620 mm
Mixer weight	3500 kg

2. ESSENCE AND PURPOSE OF THE MIXING PROCESS

The twin-shaft paddle mixer is designed to create a homogeneous and evenly moistened mass. Two paddle shafts rotating in the trough. The blades are arranged in a helical line. In a direct-flow mixer, both shafts move the material in one direction during rotation and mix. Steam is fed into the mass from below through a scaly bottom so that the holes are not clogged with clay. At the same time, part of the clay turns into slip, which is collected in containers (mud collectors) located under the scaly bottom.

The trajectory of the mixed mass: feed opening, trough, shaft blades, humidification with steam and / or water. Used in the production of clay bricks by the plastic method.

Advantages:

Continuous equipment;

The presence of steam humidification;

Warming up, increasing the plasticity of the mass.

The disadvantage is the complex design.

The mixer consists of a trough-shaped welded body, driven and driven shafts with blades and a drive. The rotation of the shafts is transmitted from the electric motor through a friction clutch, a gearbox, a coupling and a spur gear located in a closed box. Steam is supplied through the bottom of the housing and condensate is discharged. The lower part of the case is protected by thermal insulation and a casing to retain heat. In the upper part of the body there is a perforated pipe for irrigating the mass with water. The clay mass is fed through the loading opening in the upper part of the body, and then mixed with blades rotating towards each other, which advance the mass to the discharge opening located at the bottom of the body. During stirring, the mass can be moistened with water or steam. The speed of movement of the mass to the unloading hatch, and hence the performance of the mixer depends on the angle of rotation of the blades of the mixing shafts. With an increase in the angle of rotation, the productivity of the mixer also increases. At the same time, the quality of mass mixing also depends on the angle of rotation of the blades. With a decrease in the angle of rotation of the blades, the quality of mixing of the mass improves.

The mixer is used in factories producing bricks, tiles and other building ceramic products.

3. TECHNOLOGICAL PROCESS FOR PRODUCTION FROM GRAtFIGHT CERAMICS

The production of ceramic wall materials is mainly based on the use of plastic molding and semi-dry pressing technology. Last years the technology of plastic molding from low-moisture ceramic masses using coal enrichment waste is gaining popularity.

The traditional technology of plastic molding from clay mass with a moisture content of 18-24% assumes the following main stages in brick production: preparation and processing of clay mass with additives (leaning and burning out), molding, cutting timber and laying raw materials on vehicles for drying, firing and packaging finished products (Fig. 1.1).

In the extraction and processing of clay mass, a bucket-wheel excavator, a clay loosener, a box feeder, runners, rollers, and mixers are used.

The sequence of installation of the listed machines depends on the type of products, the rheological and structural properties of the raw materials. The stable operation of the entire line is ensured by the use of mechanized charge stores, which make the operation of the equipment complex independent of the supply of raw materials from the quarry and improve the quality of products. For molding products, screw belt presses are used, and for cutting timber, single-string and multi-string cutting machines are used. Thin-walled, high-quality clay products requiring vacuum processing are formed by vacuum presses, which are usually combined with a mixer. Vacuum-free presses are usually used to form solid bricks.

The equipment that ensures the laying of raw materials on vehicles for drying and firing depends largely on the type of dryers and kilns. The most common are chamber, tunnel and conveyor dryers. When using dryers of low productivity, the raw material is placed on rails and frames (wooden and aluminum) or on pallets. Depending on the type of dryer, various types of trolleys are used, on which the products are dried. To transfer drying trolleys from dryers to kilns and return empty trolleys to their original position, electric transfer trolleys of various designs are used. The design of the machines that unload the drying trolleys and load the dried products onto the kiln trolleys, as well as the shape and number of stacks on it, depend on the size and type of furnaces. Pushers and trolleys are used to move loaded and empty drying and kiln trolleys both outside the dryers and kilns and inside them. Finished products are unloaded from the kiln cars 15 and packaged using automatic unloaders and baggers, which provide bandaging of the transport package with tapes for transportation to the construction site.

A variety of plastic molding of wall materials is molding from a clay mass of low humidity. It is provided by screw presses with a drive power that is much higher than the drive power of presses that form products from clay mass of normal molding moisture. If the mechanical strength of the raw material allows, then the raw material is placed on a kiln car to combine drying and firing.

Resource-saving molding technology using coal enrichment waste (the degree of waste utilization is up to 100%) is gaining popularity. In this case, the technological line includes, along with the traditional set of equipment, special machines for processing coal preparation waste and screw vacuum presses of a special design with an increased power drive.

Distinguish plastic molding with clay powder obtained by semi-dry pressing technology. The powder is mixed in a mixer with additives, moistened and fed into a screw press.

An analysis of the work of domestic and foreign equipment complexes shows that the technical level and the main design and technological features of the equipment are determined by the method of laying raw material on drying and oven vehicles. Various technological lines of plastic molding, equipped with various equipment, can be divided into four groups according to the laying method: rack (frame), pallet, rack, stack drying.

Rice. 1.1. Technological scheme for the production of ceramic bricks by plastic molding:

1 -- bucket-wheel excavator; 2 - tipping trolley; 3 - electric locomotive or dump truck; 4 - crusher; 5 - screen; 6 - feeder; 7 - clay mixer; 8 - mixer; 9 -- belt screw press; 10 - automatic cutting and stacking of raw materials on drying trolleys; 11 -- drying trolley; 12, 17 -- power transmission trolley; 13, 18 - pushers; 14 - dried; 15 -- kiln trolley; 16 - automatic reloading of dried bricks on a kiln trolley; 19 - tunnel oven; 20 - automatic unloading of kiln cars and baling; 21 - wet grinders; 22 -- stone-releasing rollers; 23 -- box feeder; 24 - clay loosener.

Comparison of complexes based on various ways drying and firing, indicates that the transition from low-capacity drying trolleys (rails and frames) to more capacious ones (pallets) creates favorable conditions for the operation of transport systems, ensures the achievement of a higher technical level of equipment and better technical and economic performance of the complex as a whole .

On fig. 1.2 shows a diagram of the production of bricks by semi-dry pressing. The technological line ensures the sequential execution of the following operations: extraction of clay, its drying, grinding, preparation of additives, mixing and moistening of the mass. The powder is pressed in the mold of a mechanical or hydraulic press, and the raw material is stacked in piles on a kiln trolley for firing, and, if necessary, for drying. Fired products are unloaded, packaged and sent to the construction site.

A variation of the semi-dry pressing method is a resource-saving method of pressing using coal preparation waste, in which waste preparation machines are included in the production line.

In addition, semi-dry pressing is used using the slip method for preparing press powder. In this case, a spray dryer is introduced into the production line, which ensures the production of clay powder with a moisture content of 8.5-9.5%. The powder is prepared by dissolving quarry clay, cleaning the obtained slurry from foreign inclusions and spraying the slurry with drying.

Rice. 1.2 Technological scheme for the production of ceramic bricks by semi-dry pressing:

1 - trolley or dump truck; 2 -- box feeder; 3 - stone-revealing rollers; 4,6,9 - conveyors; 5 - drying drum; 7 -- lamellar feeder; 8 - clay store; 10 - dry grinding runners (disintegrator or mill); 11 - elevator; 12 - vibrating sieve; 13 -- bunker; 14 - feeder; 15 -- mixer (humidifier); 16 - a press with a raw stacker on a kiln trolley; 17 -- kiln trolley; 18 - dried; 19 -- electric transmission trolley; 20 -- pusher; 21 - tunnel oven; 22 -- automatic unloader and bagger.

4. DESCRIPTION OF THE DESIGN OF THE TWIN SHAFT PANE MIXER

Clay and additives in a predetermined proportion are continuously loaded into the mixers and mixed by rotating blades mounted on shafts, which simultaneously advance the mixture to the discharge opening. Mixing speed and mass processing are regulated by changing the angle of inclination of the blades.

If the productivity of the mixer exceeds the productivity of the clay-working and forming machines that follow it, then to eliminate frequent stops, the number of shaft revolutions is reduced.

The best mixing and processing of plastic masses is obtained when the mass filling the mixer body covers the shafts, but not more than 1/3 of the height of the blades in the upper position. The distance between the end of the blade and the wall of the mixer trough should not be more than 2-3 cm. The mixer must not be overloaded.

The body of the mixer must be covered with a metal grate. Standing on it, as well as pushing the mass through the grate with any object is prohibited. It is possible to take a sample of clay from the mixer during its operation only with a special scoop. During operation, it is not allowed to open the lid and remove the grate.

Before stopping work, the machines that feed the material into the mixer are first turned off, and after the entire mass has been worked out, the electric motor and the device transporting the processed material are turned off.

At the end of the shift, the shaft with knives and the mixer body must be cleaned of adhering mixture from the inside and outside. When the mixer blades are worn out, it is necessary to replace them or weld them with wear-resistant alloys OI-15 and OI-7. The use of these alloys increases the service life of the blades by more than 5 times.

5. COMPARATIVE CHARACTERISTICS OF MACHINES AND EQUIPMENT FOR MIXING CLAY MASS

Equipment characteristic	NAME EQUIPMENT
	Two-shaft paddle mixer SMK 125A	Two-shaft paddle mixer SMK 126A	Double-shaft paddle mixer SMK 125B	High-speed paddle mixer SMS 95A-1 (with rubber housing)	High-speed paddle mixer SMS 95A-1 (with metal body)	Twin-shaft mixer SM 727A	Two-shaft paddle mixer SMK 125B
Productivity, t/h
The diameter of the circle described by the blades, mm
Distance between axes of paddle shafts, mm
Aggregate size, mm, no more
Shaft (drum) rotation frequency, s-1
Power, kW, no more than the drive (rotor) of the skip hoist
Rotation frequency, rpm, no more
Overall dimensions, mm length width	5250 1670	5900 1700	3642 1600	6830 1700	6830 1700	3165 975	3470 1460
Overall dimensions without drive, mm length width	3670 1252	4260 1392		5000 1612	5000 1612	2770 740
Weight, kg general without drive	3200	4400	3000	7750	7400	1000	2650

6. DESCRIPTION OF THE INSTALLATION OPERATION

A two-shaft continuous paddle mixer consists of a trough-shaped body 2, closed by a lid 1, in which horizontal shafts 3 are placed, with blades 5 mounted on them. The shafts are driven towards one another by an engine 10, through a friction clutch 9, a gearbox 8 and a gear pair 7 .

The blades are set at angles at which the optimal ratio of circumferential and axial particle velocities is achieved, which ensures the required time for the components to pass from the window 6 to the discharge hatch 15 and, consequently, the quality of mixing.

To moisten the mixture through the gaps in the scaly bottom 14, steam enters, which is supplied through the pipe 13 through the distributors 12. To reduce heat loss, the lower part of the body is closed by a casing 11 filled with mineral wool. The mass can also be moistened with water supplied through the collector 4.

The mixing process in continuous mixers is carried out by mechanical action on the components of the mixture of rotating blades while moving the mixed mass from the place of loading to the place of unloading.

The working body of the mixers are one or two horizontal shafts rotating towards each other with blades fixed on them along a helical line. Mixing is carried out inside a metal fixed body with a grooved shape.

7. CALCULATIONS OF MAIN PARAMETERS

The performance of continuous mixers with horizontal paddle shafts is determined by the speed of movement of materials along the axis of the body and its cross-sectional area and in general can be written as follows:

where Q v- speed of material movement along the mixer body, m/s; BUT- cross-sectional area of the material flow, m 2 .

With some assumption, the working body of such a mixer can be considered as an auger with an intermittent screw. In this case, the axial velocity of the material can be determined from the expression

where k vz - coefficient of return of the mixture for the blade, equal to 0.6 ... 0.75; d- the number of blades within one helical pitch; S- pitch of the helix of the blades, m; b - angle between the plane of the blade and the plane normal to the axis of the mixer shaft, b = 10…45 0 ; n- shaft rotation, s -1 ; R n- outer radius of the blade, m.

Area BUT, m 2 , the cross section of the material flow with a sufficient degree of accuracy:

where c- filling factor of the mixer body, equal to 0.5 ... 0.8.

Substituting the values A And v into the formula, we get the following expression to determine the performance Q, m 3 / h:

In continuous mixers with horizontal shaft blades, the power is expended to overcome the following resistances: 1) frictional resistance of the mixture against the housing walls; 2) transportation of the mixture to the place of unloading; 3) cutting the mass of the mixture during its mixing; 4) friction resistance in drive parts and assemblies.

Power , to overcome the frictional resistance of the mixture against the walls of the housing during mixing and transportation can be determined with sufficient reliability by the formula, kW,

where Q- mixer capacity, m 3 /h; R- volumetric mass of the mixture, kg / m 3; g- free fall acceleration, m/s 2 ; w is the coefficient of resistance to the movement of the mixture, it is recommended within 4 ... 5.5; / - working length of the mixer body, m.

Power R 2 , kW required to cut the mass of the mixture by the blades during their rotation is determined by the expression:

where to p - specific resistance of the mixture to cutting, for cement concrete mixtures k = (3.0 ... 6.0) -100 2 Pa; b- average blade width, m; i - the number of blades, simultaneously immersed in the mass of the mixture on one shaft; z is the number of bladed shafts; R„, R b - outer and inner radius of the blade; m; - angular velocity of the bladed shaft, rad/s, \u003d 2Pp.

The power consumption for determining the friction resistance in the units and parts of the drive is taken into account with the calculation of the efficiency factors, which is either calculated or taken within 0.65 ... 0.85.

Then the required engine power R dv for this mixer:

The performance and power figures are almost the same. The tabular value for SMK-18 performance is 50 m 3 / h, and according to our calculations it turned out 46 m 3 / h. The tabular value for the SMK-18 power is 30 kW, and according to our calculations, it turned out to be 26 kW. This is due to the fact that we cannot take into account all factors and take accurate data for calculation.

Let us determine the annual productivity of the mixer with two shifts of eight hours and 247 working days a year.

8. HEALTH AND ENVIRONMENTAL MEASURES

Pollutants coming from the enterprises for the production of ceramic products, depending on specific technological processes, can get into the air with emissions, with effluents into water bodies and accumulate on the surface of the earth in the form of waste. Impact on environment also make noise and unpleasant odors. The nature and level of air pollution, the amount of solid waste and Wastewater depend on various factors, in particular, on the type of raw materials used, excipients, fuel, as well as on the method of production:

* air emissions: during the production of ceramics, dust / particulate matter, soot, gaseous substances (oxides of carbon, nitrogen, sulfur, inorganic compounds of fluorine and chlorine, organic compounds, heavy metals) can be released

* wastewater discharges: mostly contain mineral (suspended particles) and other inorganic components, a small amount of various organic substances, as well as heavy metals

* technological losses / production waste: waste in the production of ceramic products mainly consists of various sediments, broken products, used gypsum molds and sorbing agents, dry residue (dust, ash) and packaging waste

* energy consumption/CO2 emissions: all sectors of the ceramics industry consume a significant amount of energy, since the main stages of the process include drying and subsequent firing at a temperature of 800 to 2000 °C. Currently, in the EU member states, mainly natural and natural materials are used for firing. liquefied gas(propane and butane), EL brand fuel oil, in addition, heavy fuel oil, liquefied natural gas, biogas / biomass, electricity and different kinds solid fuel(coal, petroleum coke).

From this it follows that in the production of ceramics, all kinds of pollution occur. There are many ways to clean them.

The main conditions for improving the ecology in the country are: rational use, protection and spending of natural reserves, ensuring environmental safety and anti-radiation measures, increasing and shaping environmental thinking among the population, as well as controlling the environment in industry. Environmental protection at the enterprise has identified a number of measures to reduce the level of pollution generated by enterprises:

Identification, assessment, constant monitoring and limitation of the emission of harmful elements into the atmosphere, as well as the creation of technologies and equipment that protect and conserve nature and its resources. Development of legal laws aimed at environmental protection measures and material incentives for meeting the requirements and preventing a set of environmental measures. Prevention of the environmental situation by allocating specially designated areas (zones). In addition to the environmental safety of the facility (environmental protection at the enterprise), life safety (BZD) at the enterprise is no less important. This concept includes a complex of organizational enterprises and technical means to prevent the negative impact of production factors on a person. To begin with, all employees of the enterprise attend a safety course, which is instructed by the immediate supervisor or labor protection worker. In addition to simple safety precautions, workers must also comply with a number of rules on the technical requirements and regulations of the enterprise, as well as maintain sanitary and hygienic standards and the microclimate in the workplace. All norms and rules of environmental and work safety must be defined and recorded in a specific document. The environmental passport of an enterprise is a comprehensive statistics of data that reflects the degree of use of natural resources by a given enterprise and its level of pollution of adjacent territories. The environmental passport of the enterprise is developed at the expense of the company after agreement with the relevant authorized body and is subject to constant adjustment due to re-profiling, changes in technology, equipment, materials, etc. For the correct preparation of the passport of the enterprise and in order to avoid fraud, the control of the content of harmful substances in the nature surrounding the enterprise is carried out by a special environmental control service. Service employees are involved in filling out and processing all columns of the environmental passport, taking into account the total impact of harmful emissions into the environment. At the same time, the permissible concentration levels of harmful substances in the territories adjacent to the enterprise, air, surface layers of soil and water bodies are taken into account.

CONCLUSION

The invention relates to equipment for the production of building ceramics (bricks, tiles), and in particular to devices for preparing ceramic mass for molding by mixing, processing and, if necessary, cleaning from foreign inclusions.

To prepare the ceramic mass for molding, two devices installed in series one after another are usually used: a mixer for mixing the components at the macro level (evenly distributing them over the volume), a screw blower with a filter grid for processing the ceramic mass and cleaning it from foreign inclusions. Moreover, mixing is carried out in a twin-shaft paddle mixer, which is significantly superior in efficiency to a single-shaft mixer.

This division of the process makes it possible to provide rational technological and design parameters for each device, but the presence of two devices with drives, control systems, frames, etc. reduces the technical and economic indicators of this stage of the technological process, increasing the dimensions of the equipment, metal consumption, labor intensity of maintenance and repair.

LIST OF USED LITERATURE

1. Construction machines T.2. Equipment for the production of building materials and products. M.N. Gorbovets, 1991. - 496 p.

2. Technology of building ceramics. I.I. Frost, 1972. - 416 p.

3. Mechanical equipment enterprises of building materials, products and structures. M.Ya. Sapozhnikov, 1976. - 384 p.

4. Machinery and equipment for ceramics and refractory factories. A.P. Ilyevich, 1968. - 355 p.

5. Construction machines. Directory. In 2 vols. F.A. Lapir, 1977.-491 p.

Hosted on Allbest.ru

...

Description

The WTS twin-shaft paddle mixers are counter-rotating double-shaft, parallel drum mixers equipped with paddles to ensure a homogeneous mixture regardless of the particle size and bulk density of the blended products. The high quality of the mixture is achieved due to the efficiency of the multidirectional rotation of the blades overlapping each other.

This design provides gentle mixing in a short time, as well as low energy consumption.

In the intensive mixing process, even fragile product particles are not destroyed.

The mixer can be started under load.

Function

Due to the special design and arrangement of the mixing paddles on both shafts, the WTS batch paddle mixer allows you to create a fluidized bed.

This is made possible by two different mixing technologies: turbulent motion and displacement. In combination with low load, free movement of the mass of the product occurs. In the fluidized bed, powders and granular materials are optimally distributed in a very short time. Therefore, the WTS Twin Shaft Paddle Mixer offers a high level of uniformity and a high mixing speed.

The mixing process on the WTS twin-shaft paddle mixer is particularly efficient due to the overlapping rotation of the paddles in opposite directions. This ensures the homogeneity of the mixture, regardless of the particle size and bulk density of the mixed products. This design provides gentle mixing in a short time, as well as low energy consumption. Twin-shaft mixers WTS are used for mixing dry bulk materials (powders, granules, short-fiber products), dry bulk materials with liquids (humidification, granulation), as well as low viscosity pastes.

Peculiarities

Productivity: from 48 to 5000 liters per batch
Coefficient of variation: less than 3%
Mixing ratio: 1/100,000
End bearings with different types shaft seals purged with air/gas
Large double bomb bay
Mixing chamber made of carbon steel or 304L stainless steel

Advantages

Excellent mix reproducibility
Lowest possible loss (0–0.5% volume)
Minimum unloading time thanks to double bomb bay
Durable Equipment
Easy cleaning and access to all internal parts of the faucet
Combination of production experience and test equipment

Options

316L stainless steel mixer chamber and shaft
Painting for use in the food industry
Rotating liquid spray bar
Fluid supply equipment
Mixing chamber with heating/cooling mantle
Removable paddles

The owners of the patent RU 2622131:

The invention relates to equipment for mixing bulk products and can be used in the feed industry, at the enterprises of the agro-industrial complex and in other industries.

Known mixer high-speed single-shaft paddle periodic action DFML "SPEEDMIX" company "Buhler", Switzerland (magazine "Feed internation". - No. 8. - 1996. - S. 25-26) for mixing bulk products, including a mixing chamber, a shaft with four blades that provide countercurrent movement of products with a mixing time of 90 s. The quality and time of mixing the components of the mixture are directly proportional to the number of blades and the frequency of their rotation.

The disadvantage of this mixer is the high rotational speed of the paddle shaft, due to the small number of blades, which leads to significant energy costs.

Known twin-shaft paddle batch mixer company "Forberg", Norway (Norwegian Patent No. 143519, B01P 7/04 dated 09/15/76), including a mixing bath, two horizontal paddle shafts that rotate in opposite directions. The working body of the mixer has 24 blades, 12 on each shaft with different angles rotation about the axis of the shaft. At the end walls there are four blades with a rotation angle of 0 degrees and four blades with a rotation angle of 55°, the remaining 16 blades have a rotation angle of 45°. The trajectories of rotation of the blades of one shaft intersect with the trajectories of rotation of the blades of another shaft.

During the operation of the mixer, the paddle shafts move the product in four different directions with the formation of a homogeneous mixture within 40 seconds.

The disadvantage of the design of this mixer is: the complexity of the design of the working body, due to the presence a large number blades, which significantly increase the consumption of energy expended to overcome the large forces that occur in each blade when they enter and leave the product during the mixing process; obligatory synchronization of the rotation of the blade shafts, in which each row of blades of one shaft enters between two adjacent rows of blades of another shaft. Failure to synchronize the rotation of the blade shafts causes jamming of the working body of the mixer, in which the blades, shaft and drive break.

The closest in technical essence and achieved effect is the mixer (Patent for utility model No. 61588, B01F 7/04. Mixer. Afanasyev V.A., Shcheblykin V.V., Kortunov L.A. Applicant JSC "All-Russian Research Institute feed industry"), including a mixing bath, two shafts with blades, a drive, characterized in that in order to simplify the design, reduce metal consumption and increase the reliability of operation, 12 blades are installed on the blade shafts with rotation angles of 45 ° relative to the shaft axis, while on the first six blades are located on the shaft along a helical spiral through 120 °, three blades with the right direction of the helix, and three others - with the left, on the second shaft there are also six blades along similar helical spirals with left and right directions. The blade shafts are installed at a distance equal to the double height of the blade with the rack, at which the rotation paths of the blades of each shaft do not intersect.

The disadvantages of the known mixer is the significant energy consumption required to overcome the great effort at the entrance of the blades into the product; long mixing times due to the low turbulent flow of the components to be mixed.

The technical objective of the invention is to increase mixing efficiency and reduce specific energy consumption while achieving the best mixing uniformity due to the implementation of a progressive mixing method based on mechanical fluidization in combination with cross counterflow, as well as reducing the duration of the mixing process.

This goal is achieved by the fact that in a twin-shaft mixer, including a mixing bath, two shafts with blades, a drive, while the blades mounted on the shafts are rotated 45 ° relative to their axis, and on the first shaft the even blades are located in a helical spiral through 120 ° with the right the direction of the helix, and the odd blades - with the left, on the second shaft there are also even and odd blades along similar helical spirals with left and right directions, inside each hollow bladed shaft a fixed axis is coaxially mounted, on which, with a pitch equal to the pitch of the blades on the bladed shaft, cams are installed, with the outer surface of which the rollers installed at the ends of the racks of the blades interact, and springs are put on the racks located between the inner diameter of the bladed shaft and the rollers, top part the body of the mixing bath is made along a complex line corresponding to the trajectory of the blades, due to the outer surface of the cams, the upper edge of the blade in contact with the inner surface of the mixing bath is made of elastic material, nozzles for supplying liquid and viscous components are installed in the end walls of the upper part of the body of the mixing bath .

In FIG. 1 shows a frontal view of a twin-shaft mixer; in fig. 2 is a top view of a twin-shaft mixer; in fig. 3 is a side view (left) of a twin-shaft mixer; in fig. 4 - section A-A frontal view of a twin-shaft mixer; in fig. 5 - section of the paddle shaft and view A of the paddle shaft; in fig. 6 - photo of a twin-shaft mixer; in fig. 7 - computer version general view twin shaft mixer; in fig. 8 - three-dimensional image of the left and right shafts of a two-shaft mixer; in fig. 9 - scheme of rotation of the left and right shafts of a two-shaft mixer.

The twin-shaft mixer (Fig. 1-3) contains a mixing bath 1 with end walls 2 and 3, a loading pipe 16, an unloading pipe 17, horizontal hollow bladed shafts 4 and 5 rotating in the opposite direction, a drive 6 for rotating the bladed shafts 4 and 5 and a drive 7 for unloading the finished mixture from the mixing bath. The proposed design of the drive 6 of the shafts 4 and 5 from one electric motor using a belt drive and two parallel gears ensures the rotation of the bladed shafts 4 and 5 is synchronized. In this case, the shaft 4 rotates clockwise, and the shaft 5 rotates counterclockwise (Fig. 9).

On shafts 4 and 5, blades 10 are installed with racks 12, at the ends of which there are rollers 13 (Fig. 5). On the racks 12, located between the inner diameter of the hollow bladed shaft and the rollers 13, springs 11 are put on. For ease of installation and maintenance of the springs 11 and rollers 13, holes are drilled in the shafts 4 and 5, into which the bushings 14 are screwed (Fig. 5).

Inside each hollow bladed shaft 4 and 5, fixed axles 8 are installed coaxially, on which cams 9 are installed with a pitch equal to the pitch of the blades 10 on the bladed shaft.

The outer surface of the cams 9 interact with the rollers 13 mounted on the ends of the racks 12 of the blades 10.

The upper part of the body of the mixing bath 1 is made along a complex line corresponding to the trajectory of the blades 10, due to the outer surface of the Cams 9 (Fig. 4).

The upper edge of the blade 10, which is in contact with the inner surface of the mixing bath 1, is made of an elastic material.

Blades 10 are mounted on shafts 4 and 5 with a rotation angle of 45° relative to the axis of the shafts (Fig. 5). Moreover, on shaft 4, even blades are located in a helical spiral through 120 ° with the right direction of the helix, and odd blades - with the left one, on the second shaft even and odd blades are also located along similar helical spirals with left and right directions (Fig. 8 and Fig. nine). Installation on the shaft 4 of the blades 10, rotating along a trajectory that does not intersect with the trajectory of rotation of the blades 10 of the shaft 5, increases operational reliability and additionally turbulizes the flow of the mixed components of the mixture (Fig. 8 and 9).

In the end walls 2 and 3 of the upper part of the mixing bath 1 nozzles 15 are installed for supplying liquid and viscous components.

The proposed mixer works as follows.

The initial bulk components are loaded into the mixer through the loading pipe 16. The drive 6 is turned on, and the shafts 4 and 5 are rotated towards each other.

Due to the arrangement of even blades on shafts 4 and 5 along a helical spiral through 120 ° with the right direction of the helix, and odd blades with the left one, the movement of the mixture components in the mixer bath 1 has the form of a cross counterflow, because they provide the direction of movement of the mixture flows towards each other in the direction from the end walls to the center of the mixer.

The blades 10 on the basis of experimental studies are recommended to be installed at an angle of 45° to the horizontal axis of the shafts 4 and 5, since the mixing intensity is created by the formation of powerful countercurrent mass flows of the mixed mixture. When the angle of rotation of the blades decreases to zero, the linear displacement of the mass of the mixture decreases and stops at 0°, the resistance of the medium and the circumferential rotational motion of particles increases, and when the angle of rotation of the blades increases to 90°, the resistance of the medium decreases, but the intensity of movement of the particles also decreases. It was also taken into account that at an angle of rotation of the blades of 45°, the most optimal consumption of electrical energy was ensured.

The defining parameter of the mixer is the blade span radius. The circumferential speed of the blades 10 on the shafts 4 and 5 depended on the value of the radius, and as our studies showed, it is better to make it variable, which directly affected the nature of the mixing of the mixture components.

Experimental studies of a twin-shaft mixer (Fig. 6), carried out at peripheral speeds from 1 to 2.1 m/s, show that the peripheral speed V p =1.31...1.45 m/s corresponds to the minimum power consumption. When using the equality of circumferential speeds, at which the circumferential speed of the extreme points of the blades 10 for a prototype mixer (Fig. 6 and 7) with a kinematic similarity is assumed to be 1.4 m/s, the rotational speed of the blade shafts 4 and 5 of the prototype mixers with a capacity of 2, 5, 10 and 20 t/h are 50, 37, 29 and 23 rpm.

The blades 10, rotating with a variable span radius, give a variable circumferential speed of movement of the mixture components. A variable span radius (the blades have a minimum span radius from the bottom point and a maximum through 90° along the direction of rotation) is created due to the movement of the rollers 13 along the surface of the cams 9 during the rotation of the blades 10. At the same time, they form a dusty mixture based on mechanical fluidization, which in in combination with the cross counterflow created by the arrangement of even blades on shafts 4 and 5 along a helical spiral through 120° with the right direction of the helix, and odd blades with the left one, creates the effect of mechanical fluidization of the mixture, into which it is convenient to introduce finely dispersed liquid components (Fig. .8 and 9). If necessary, liquid and viscous components are supplied from the spray nozzles 15 located in the end walls 2 and 3 of the upper part of the mixing bath 1.

Thus, a cause-and-effect relationship was revealed between the variable radius of the blades and the value of the rotational speed of the bladed shafts 4 and 5 of the mixer, which ensures the minimum consumption of electrical energy and obtaining a homogeneous mixture in a short time interval.

Then the drive 7 is turned on, which opens the flaps of the discharge pipe 17, and the finished mixture is unloaded from the mixing bath 1.

The test results of the experimental sample of the twin-shaft mixer showed that it provides the homogeneity of the mixture at a mixing time of 30 s (Fig. 6).

Thus, the use of the invention will allow:

Optimize the process of mixing feedstock with different particle size distribution and physical and mechanical properties by maintaining a variable span radius of the blades 10 and imparting a variable circumferential velocity of the mixture components;

Expand the scope of application due to the formation of a dusty mixture, due to the cross counterflow created due to the arrangement of even blades on the shafts 4 and 5 in a helical spiral through 120 ° with the right direction of the spiral, and odd blades - with the left;

Obtain homogeneous multi-component mixtures of high quality due to the effect of mechanical fluidization and uniform introduction of liquid and viscous components into a mixture of bulk materials.

A twin-shaft mixer, including a mixing bath, two shafts with blades, a drive, characterized in that, in order to increase the mixing efficiency and reduce the duration of the mixing process, the blades mounted on the shafts are rotated by 45º relative to their axis, and on the first shaft the even blades are arranged in a helical spiral through 120º with the right direction of the helix, and the odd blades - with the left, even and odd blades are also located on the second shaft along similar helical spirals with the left and right directions, inside each hollow bladed shaft a fixed axis is coaxially installed, on which, with a pitch equal to the pitch of the location blades on the blade shaft, cams are installed, with the outer surface of which rollers interact, installed at the ends of the racks of the blades, and springs are put on the racks located between the inner diameter of the blade shaft and the rollers, the upper part of the mixing bath body is made along a complex line corresponding to the trajectory of the lane displacement of the blades due to the outer surface of the cams, the upper edge of the blade in contact with the inner surface of the mixing bath is made of elastic material, nozzles for supplying liquid and viscous components are installed in the end walls of the upper part of the body of the mixing bath.

Similar patents:

The kneading device (2) has at least two shafts (12, 14), on which the tools (18, 22) located in the kneading chamber (6) are fixed. At least one of the tools (18, 22) is made to transport the dough from the loading zone (10) in the feed direction (20) to the discharge opening (8).

The invention relates to agriculture, in particular to devices for preparing feed on livestock farms and complexes. The device for mixing dry feed and dry additives consists of a dry feed hopper, in which an unloading auger is installed, made in the form of a spiral round section, in the unloading zone, the unloading auger is made in the form of U-shaped blades of circular cross section, made of a rod with a diameter of 4 ... 10 mm and rotated relative to the axis of rotation by an angle α = 5 ... blades of circular cross-section there is a mesh made in the form of a plate with rectangular punched holes with a width across the screw shaft of 15 ... 30 mm and a length of 30 ... 70 mm with jumpers of 2 ... 4 mm; in two to seven sections on a common shaft bladed drums with flat radial blades in the amount of 6 ... 20 pcs.

The invention relates to devices for mixing materials with poor flowability and differing in density, for example, for mixing prescription components of animal and vegetable origin, as well as products of microbial synthesis, and can be used for the preparation of feed in agriculture.

The present invention relates to a trapping device that traps powdered addition agent expelled from a pressure kneader. closed type for kneading a high-viscosity plasticizable material such as rubber, plastic, and ceramic; and a method for trapping a powdered addition agent using a trapping device.

The invention relates to the chemical industry and can be used for the processing of organic raw materials. The plant includes a feedstock supply system (1), an anaerobic bioreactor (2), a biomass heater, a biogas removal system (3), a biomass removal system (7), a control system technological process (6).

The invention relates to a mixer for the preparation of dental material and can be used in medicine. The mixer (10) for the preparation of dental material contains a mixing barrel (17) and a mixing rotor (16), inlet pipes (13, 14) of the mixer and an outlet pipe (15).

The invention relates to the field of obtaining spherical powders (SFP) for small arms. The method for producing spherical powder includes mixing the components in a reactor, preparing a powder varnish in ethyl acetate, dispersion in the presence of glue and distillation of the solvent, while dispersion of the powder varnish is carried out in a reactor with a volume of 6.5 m3 with variable-angle paddle mixers installed in the lower cantilever part of the shaft in 3-4 rows at an angle of 90 ° relative to the previous blade.

The invention relates to the processing of man-made materials and can be used in various industries: chemical, energy, fuel, as well as in the building materials industry for the preparation of composite mixtures with finely divided fibrous materials. Technological module for mixing technogenic fibrous materials consists of vertical 1 and horizontal 7 mixers with blades installed in series. The blades of the vertical mixer 4 are double-threaded helical, in the form of helicoidal surfaces of a unidirectional entry towards the material unloading. The blades 11, 13 of the horizontal mixer in the loading and unloading parts are made as single-threaded helical unidirectional towards the material unloading. Oppositely directed two-way helical blades 12 are installed between them. Horizontal mixer 7 contains a block for mechanical pre-compaction of the mixture, represented by external and internal cones made of two cones. The method of mixing technogenic fibrous materials includes mixing with an organic binder, steam humidification and mechanical compaction of the mixture. Mixing is carried out in two stages. At the first stage, turbulent-gyratory mixing takes place. At the second stage, recirculation mixing with steam humidification takes place. EFFECT: invention provides mixing of technogenic fibrous materials with different physical and mechanical characteristics and improving the quality of the mixture by stage-by-stage high-speed mixing of the mixture with the organization of internal recycling at each stage of their mixing and successive increase in its density by means of mechanical pre-compaction. 2 n.p. f-ly, 4 ill.

The invention relates to the field of mechanical engineering, where the initial components are mixed into a homogeneous mass, and can be used in agriculture and other industries. In a twin-shaft mixer, the blades are included in sets of assemblies that are mounted on each of the four sides along horizontal square shafts along the length of the mixer and have round ends mounted in cylindrical housings with sealed ball bearings. At the same time, at the upper end of each vertical end piece, a blade is fixed in the slots, which is made in the form of radial plates with a thickness of at least 10 mm, a width of no more than 80 mm, and the lower end of each shank is made in the form of a worm with milled involute teeth, which provide the ability to rotate shoulder blades in vertical plane by 30°, 45° and 60°, according to the results of the bulk density of bulk materials, respectively, 0.30, 0.55 and 0.75 t/m3, and the rotation of the horizontal round shafts of the drive for turning the blades and the square tube shafts of the mixer is carried out by electric motors. Mixing homogeneity of at least 98% is achieved. The invention provides an increase in the reliability of sets of assembly units and a reduction in metal consumption and energy consumption of the entire process, respectively, by more than 25% and 35%. 2 ill.

The invention relates to equipment for mixing bulk products and can be used in the feed industry, at the enterprises of the agro-industrial complex and in other industries. The twin-shaft mixer contains a mixing bath, two shafts with blades, a drive, while the blades mounted on the shafts are rotated by 45º relative to their axis, and on the first shaft the even blades are located in a helical spiral through 120º with the right direction of the helix, and the odd blades - with the left one, even and odd blades are also located on the second shaft along similar helical spirals with left and right directions, a fixed axis is coaxially installed inside each hollow bladed shaft, on which cams are installed with a pitch equal to the pitch of the blades on the bladed shaft, with the outer surface of which they interact rollers mounted on the ends of the racks of the blades, and on the racks located between the inner diameter of the bladed shaft and the rollers, springs are put on, the upper part of the body of the mixing bath is made along a complex line corresponding to the trajectory of the blades, due to the outer surface of the cams, the upper edge of the blade in contact with inside The front surface of the mixing bath is made of an elastic material; nozzles for supplying liquid and viscous components are installed in the end walls of the upper part of the mixing bath body. The technical result of the invention is to increase mixing efficiency and reduce specific energy consumption while achieving the best mixing uniformity due to the implementation of a progressive mixing method based on mechanical fluidization in combination with cross counterflow, as well as reducing the duration of the mixing process. 9 ill.

Details Created on 03/05/2012 22:28 Updated on 08/07/2012 16:52 Author: Admin

For mixing clay during semi-dry and plastic molding of ceramic products, as well as for preparing the charge in glass, silicate and other industries, single-shaft and twin-shaft paddle mixers of continuous and cyclic action are widely used.

In the latter case, a higher quality of products is achieved, since the steam heats up the mass and then, condensing, moistens it. The main parameter of paddle mixers is their productivity. The industry produces mixers with a productivity (for clay): 3, 5, 7, 18 and 35 m 3 / h with a blade diameter of 350, 600 and 750 mm, respectively.

The figure shows twin shaft paddle mixer continuous action. It consists of a trough-shaped body 2, closed by a lid 1, in which horizontal shafts 3 are placed, with blades 5 mounted on them. The shafts are driven towards one another by an engine 10, through a friction clutch 9, a gearbox 8 and a gear pair 7.

To ensure high quality mixing twin shaft countercurrent mixers. Structurally, they are identical to the mixer shown above, but the angles of the blades on the shafts are opposite in sign. This arrangement of the blades creates certain counter flows of particles, with the general direction of movement of the mixture towards the unloading window, since the angular velocity of shaft 1 is greater than the angular velocity of shaft 2.

The installation angles of the blades and the ratio of the angular velocities of the shafts for specific conditions are determined empirically. For preliminary mixing of dry mixtures, single-shaft paddle mixers are used. Most often, they perform two functions: they mix and move materials, for example, from bunkers to other units. Structurally, such mixers are similar to those discussed above, but have one paddle shaft.

For especially thorough mixing (hard-to-homogenize mixtures), batch mixers are used, for example, twin-shaft mixers with Z-shaped blades. Depending on the required homogeneity, the duration of mixing in such mixers can be 20-30 minutes.

Twin-shaft continuous paddle mixers can also operate in a cyclic mode if they are provided with a shutter and the blade installation pattern is changed.

A small twin-shaft paddle mixer visually (video):

The basis for calculating the performance of cyclic mixers:

where V is the volume of the mixer
z is the number of cycles per hour.

General performance of continuous mixers:

P \u003d 3600 F v os,

where F is the cross-sectional area of the material flow in the mixer, m 2 ;
v oc - axial speed of material movement, m/s.

With some assumption, the working elements of a paddle mixer can be considered as an auger with an intermittent screw. The axial velocity of the material (m/s) depends on the circumferential speed of the blades, their shape and installation pattern.

Twin Shaft Paddle Mixers WTS allow you to get high-quality mixtures in the shortest possible time with the lowest possible energy consumption. The processing of the product is carried out in the most delicate way without any damage to the product during the mixing process.

The WTS Twin Shaft Paddle Mixers are batch mixers with two parallel drums and two counter-rotating shafts, equipped with paddles to ensure uniformity of the mixture regardless of the particle size and bulk density of the products to be mixed. The high quality of the mixture is achieved due to the efficiency of the multidirectional rotation of the blades overlapping each other.

This design of the WTS mixer ensures gentle mixing in a short time as well as low energy consumption.

In the intensive mixing process, even fragile product particles are not destroyed.

The twin-shaft mixer WTS can be started under load.

Function of WTS Twin Shaft Paddle Mixer

Due to the special design and arrangement of the mixing paddles on both shafts, the WTS batch paddle mixer allows you to create a fluidized bed.

The mixing process on the WTS twin-shaft paddle batch mixer is particularly efficient due to the multidirectional rotation of the overlapping paddles. This ensures the homogeneity of the mixture, regardless of the particle size and bulk density of the mixed products. This design provides gentle mixing in a short time, as well as low energy consumption. Twin-shaft mixers WTS are used for mixing dry bulk materials (powders, granules, short-fiber products), dry bulk materials with liquids (humidification, granulation), as well as low viscosity pastes.

Features of WTS Twin Shaft Mixers

Productivity: from 48 to 5000 liters per batch;
Coefficient of variation: less than 3%;
Mixing ratio: 1/100,000;
End bearings with various types of shaft seals purged with air/gas;
Large double bomb bay;
Mixing chamber made of carbon steel or 304L stainless steel.

Benefits of WTS paddle mixers

Excellent reproducibility of mixtures;
Minimum possible losses (0–0.5% of the volume);
Minimum unloading time due to double bomb bay;
Durable equipment;
Easy cleaning and access to all internal parts of the mixer;
A combination of manufacturing experience and test equipment.

Options for WTS mixers

316L stainless steel mixer chamber and shaft;
Painting for use in the food industry;
Rotating rod for spraying liquid;
Liquid supply equipment;
Mixing chamber with heating/cooling jacket;
Removable blades.

Mixer bladed two-shaft. Double shaft mixer. Calculations of the main parameters

Send your good work in the knowledge base is simple. Use the form below

1. TECHNICAL DATA

2. ESSENCE AND PURPOSE OF THE MIXING PROCESS

5. COMPARATIVE CHARACTERISTICS OF MACHINES AND EQUIPMENT FOR MIXING CLAY MASS

Overall dimensions, mm

length

width

5250

1670

5900

1700

3642

1600

6830

1700

6830

1700

3165

975

3470

1460

Overall dimensions without drive, mm

length

width

3670

1252

4260

1392

5000

1612

5000

1612

2770

740

Weight, kg

general

3200

4400

3000

7750

7400

1000

2650

Similar Documents

Description

Function

Peculiarities

Advantages

Options

Function of WTS Twin Shaft Paddle Mixer

Features of WTS Twin Shaft Mixers

Benefits of WTS paddle mixers

Options for WTS mixers