RU2435664C1 - Plastic material grinder - Google Patents

Abstract

FIELD: process technologies.

SUBSTANCE: invention refers to manufacturing of building materials and is applicable in processing lines of ceramic paste preparation. A grinder comprised sequenced in-built screw and actuator accommodating shaft-mounted blade knifes and rigidly fixed in-built alternating cross grids. It is a stone-separating knife that goes first along the material path, and the grid has slot openings directed from the centre out where at least a portion of the openings are transformed into stone removal grooves. The slot openings are bent through a curve approached to a spiral, and extended from the centre out and along a thickness of the grid - towards a product output hole. A blade of the stone-separating knife has an active face tangential to the shaft and forming an angle 60-90° with a tangent to any crossed partition between the grid holes.

EFFECT: invention provides higher throughput, grinding power, performance and efficiency of the device, reduced probability of self-locking and higher performance reliability.

4 cl, 6 dwg

Description

The technical field to which the invention relates.

The invention relates to the production of building materials and is intended primarily for use in technological lines for the preparation of ceramic mass.

State of the art

The most famous grinding device that performs the function of removing stony and other inclusions is stone-separating rollers, characterized by the presence of two rolls: a fast-rotating ribbed or helical roller and a slow-moving smooth one (see, for example, Prince Zolotarsky A.Z., Sheinman E.Sh. Production ceramic brick: textbook, Moscow: Higher school, 1989, pages 59-60, 76, or patent SU No. 1447398, IPC: B28C 1/20, publ. 30.12.88). Due to the large difference in the frequency of rotation of the rolls, conditions are created for the effective grinding of clods of material and the allocation of stones. However, stone-separating rollers carry out coarse preliminary grinding and make it possible to isolate only large stony fractions with a size of 30 mm or more.

The removal of smaller stony inclusions is carried out in devices such as an clay mixer with an end filter grill, as described in RU patent No. 2081746, IPC: B28C 1/14, publ. 1997.06.20.

Known clay mixer for cleaning clay from solid inclusions, containing a housing in which a pressure screw is installed and a filter grate placed across the material flow (see patent SU No. 624792, IPC: B28C 1/04, publ. 25.09.78). Material under the pressure of the screw is forced through the grate, while stones or other solid inclusions are directed outwardly to the lower container located under the grate, due to the inclined position of the latter.

Both of the above devices are characterized by a low degree of grinding of the material, increased energy consumption, and can be used only for ceramic masses, previously cleaned of large foreign impurities.

A device for grinding plastic material (see patent for invention RU No. 17800800, IPC: B28C 1/14, publ. 1992.11.30), comprising a housing with a feeding screw and a drive connected to the housing, in which a block of filtering transverse gratings is installed, for each of which, in the direction of movement of the material, is placed on a knife that cuts off chips through the holes of the gratings. The device is characterized by a high grinding intensity, however, it does not provide for the possibility of removing stony inclusions, and to prevent breakage in the event that particularly hard impurities get into the knife system, a safety key is used, which is cut off in case of jamming.

As the closest, by the presence of similar structural features, analogue to the claimed solution, a device for grinding and mixing plastic materials, mainly clay (see patent No. 2297324, IPC: B28C 1/14, published on 04/20/2007), containing a housing with a loading hopper, a screw and an actuator sequentially mounted in the housing, including knives mounted on the shaft, alternating with grids in the form of perforated disks with a central hole fixed in the housing. The first from the side of the incoming material is a stone-cutting knife, interacting with a stone-cutting lattice, which has slit-like openings directed to the periphery and turning into grooves. The body is equipped with a nozzle for removing stones.

A disadvantage of the known solution is the low efficiency due to the poor throughput of the stone-cutting lattice, which together with the four-leaf stone-cutting knife contributes to the creation of a plug at the inlet of the device.

Disclosure of invention

The task of the invention is to eliminate the above disadvantages and increase the efficiency of the device.

The problem is solved by the claimed device for grinding plastic materials, mainly clay, containing a screw sequentially mounted in the housing and an actuator, including blade knives mounted on the shaft and alternating transverse grids fixed in the housing, in which the stone-cutting knife is installed first in the direction of movement of the material and the lattice behind it is made with slit-like openings directed from the center to the periphery, where at least a part of the holes Step goes into grooves to remove stones.

What is new in the device is that the slit-like openings of the grating designed for stone extraction are bent along a curve close to the spiral and are made expanding from the center to the periphery of the grating, and along the thickness of the grating in the direction of the product outlet. In this case, the blade of the stone-cutting knife is made with a working face located tangentially relative to the shaft and forming with an tangent to any partition intersected by it between the holes of the grate an angle of 60 ÷ 90 °.

The above set of essential features of the claimed invention allowed to obtain the following positive technical results.

Firstly, to increase the throughput of the device at the input of the actuator, more specifically, at the stage of stone separation, which became possible due to the holes of the lattice with longitudinal and transverse expansion: from the center in the direction of the periphery, and along the thickness of the lattice in the direction of the product exit.

Another technical result was to obtain the effect of redistribution in the working volume of the material transferred from the stone separation section to the grinding section, in accordance with its particle size distribution (particle size), which led to an increase in the intensity of grinding of material at subsequent processing stages carried out in sections of the actuator located behind stone-cutting.

The slit-like openings of the lattice are curved in a curve close in shape to the portion of the spiral extending from the center of the lattice. In this case, the stone-cutting lattice and knife are installed in such a way that the bend of the holes of the lattice is directed in the same direction where the knife rotates and, therefore, the material moves. The shape of the holes of the lattice, the shape of the blade of the knife and their relative position provide an angle of 60 ÷ 90 ° between the working face of the knife and tangent to any partition it intersects between the holes of the lattice.

Such a constructive solution of the stone-releasing pair (grate / knife) provided the best conditions for removing stony inclusions that move along the surface of the grate and along spiral-curved holes to the periphery, without being crushed or cut, they simply “drive out” of the working space.

At the same time, the wedge-shaped expanding shape of the holes ensures that, simultaneously with the process of removing large stony inclusions, the so-called fractionation of the moved material occurs: small lumps of clay pass through the holes of the grate already near the shaft on which the knife is mounted. The clay material of the middle fractions is pressed through holes in the middle of the lattice. Larger pieces of clay move along the hole and are pushed through it at the periphery, i.e. in the zone of maximum expansion of the hole. Even larger inclusions are moved with a knife along the surface of the grate to the location of the grooves, along which they are displayed in a stone collector or pipe to remove stones.

Thus, the separation of stony inclusions occurs with the simultaneous fractionation of clay material and its redistribution in the working volume of the device in accordance with the size, so that in the next section, intended for grinding, clay material comes in a strictly defined way. Small fractions of the material are located closer to the shaft on which the knife is mounted, and larger in the middle part of the volume and closer to the periphery.

As is known, at the same angular velocity of rotation, the upper part of the blade of the knife that is farthest from the shaft has a much higher linear speed of movement than its lower part, which increases in proportion to the radius of removal from the center of rotation, due to which it has a stronger and impact effect on the material being ground .

The fractional redistribution of the material transferred from the stone separation section to the grinding section has led to the fact that larger fractions of clay material fall into the zone of stronger and more intense impact, where they are subjected to more intense, not only cutting, but also impact impacts of the blade blades, thereby increasing grinding intensity as a whole and grinding efficiency increases.

Increasing the throughput of the device and increasing the intensity of grinding material in the aggregate provided a significant increase in the productivity of the device and its efficiency.

At the same time, the aforementioned redistribution of the material made it possible to reduce the likelihood of jamming of the mechanism near the rotating shaft, thereby increasing the reliability of the device.

The housing in the installation area of the stone extraction pair is preferably made with expansion. The expansion of the working volume contributes to loosening of the material falling from the auger zone to the stone separation zone, which facilitates the removal of stony inclusions from it.

The working face of the stone-cutting knife is preferably made with a bevel that provides an acute angle between this face and the surface of the stone-cutting lattice. In other words, the working edge of the knife is inclined to the surface of the grate so that its upper part hangs over the surface of the grate. This design of the knife contributes to a better direction of the material to the periphery and facilitates its forcing through the holes of the lattice.

The working face of the knife is preferably straight along the entire length, which is the most technologically advanced. However, this does not limit another design of the working face, for example with a bend. In this case, it is only necessary to observe the condition that the angle between the working surface of the knife and the tangent to any partition it intersects between the holes (at the intersection point) is more than 60 °.

From the point of view of the throughput of the device, it is preferable to use a two-blade stone-cutting knife or a knife with a single blade.

The knives of the actuator, including the stone-cutting knife, are preferably mounted on the same shaft with a screw blade.

The design of the device is illustrated by drawings, where:

figure 1 shows a device, a General view;

figure 2 is a section aa from figure 1, shows a stone-making unit;

figure 3 is the same, view a from figure 2;

figure 4 is a section bB from figure 2, a cross section of a stone lattice;

figure 5 - stone excrement pair, isometry;

figure 6 - stone grating made by laser cutting.

The implementation of the invention

The device for grinding clay materials, shown in the drawings, contains a loading hopper 1 and a housing 2 connected to it, along the longitudinal axis of which a shaft 3 is connected, connected with a rotation drive 4.

The shaft 3 in the initial, in the direction of movement of the material zone of the body, and located under the loading hopper, is made with a screw blade 5, behind which further in the direction of movement of the material, the blade knives 6 of the actuator are rigidly mounted on the shaft, alternating with transverse grids fixed in the case 7. The first in the direction of movement of the material is a two-blade stone-cutting knife 6 ', which interacts with the stone-grating 7'.

The housing 2 in the installation area of the stone-cutting pair is made with an extension of 8 and is equipped with a pipe 9 for removing stones.

In the drawings, see FIGS. 2-5, a stone-producing assembly of the device is shown.

The holes 10 of the stone grating 7 'are bent along a smooth curve close in shape to the portion of the spiral, and are made with expansion from the center to the periphery of the grating (see Fig. 2), and with expansion s along the thickness of the grating in the direction of the product exit (cm Fig. 4). Part of the holes of the lattice 7 'located in the area of the pipe 9, made passing into the grooves 11 to remove stones.

Each blade of the stone-cutting knife 6 'has a working face 12, located tangentially with respect to the shaft 3, and made with a bevel that ensures the formation of an acute angle α between this face and the surface of the grating 7' (see Fig. 3).

The stone grating 7 'can be made by any known method. Figure 6 shows a lattice made by laser cutting, which allows you to cut holes of a given shape and parameters directly from the disk blank.

The prototype of the inventive lattice (Fig.2-5) was made by assembling from individual elements, including the supporting inner ring, the outer rim, and the strip elements placed between them, forming partitions between the holes of the lattice and made of blanks in the form of a pipe segment. In each such blank, a taper was preliminarily formed, after which the blanks were cut into 4 parts and cut at the ends at a given angle. The assembly of the lattice elements was carried out by welding.

This method of manufacturing the inventive lattice is also possible, however, the first mentioned method is preferable, as the most technological and productive, and allowing to manufacture the lattice in the form of a solid product, which ensures high reliability of the device.

The device operates as follows.

The initial plastic material, in particular clay, is poured into the hopper, from where it enters the working area of the screw 5, which primarily grinds and mixes the material, moving it to the actuator, more specifically to the first stone-releasing pair located along the material: knife 6 'and grate 7 '. The working surface 12 of the knife 6 'acts on the material, moving it along the surface of the grating 7 and at the same time pushing through the holes 10 of the grating.

The design of the stone-separating grating 7 'and the stone-cutting knife 6' ensures that at any time the angle γ between the working face 12 of the knife 6 'and the tangent to the partition 13 intersected by this face between the holes 10 of the grating 7' is 60 ÷ 90 °, due to which lumps are not cut, but expelled along these holes to the periphery.

Clay material with a grain size of 4-5 mm passes through the holes of the grate near the shaft 3. Lumps of 8-10 mm in size are pressed through holes in the middle of the grate. Larger pieces of clay up to 19-20 mm move along the holes and are pushed through it at the periphery, i.e. in the zone of maximum expansion of the openings 10. Larger inclusions are moved with a knife 6 'along the surface 14 of the grating 7' to the zone of location of the stone extraction pipe 9, where along the grooves 11 are discharged outside the grating into the volume of the pipe.

It should be noted that the specific limit values of the size of the pressed material, or in other words, the minimum dimensions of the removed inclusions, depend on the specific design parameters of the holes of the stone grating, which are calculated by the designer based on the tasks.

In the part of the device where grinding and mixing occurs through a sequence of transverse grids 7 and knives 6, the clay mass comes not only cleaned of solid large inclusions, but also redistributed in the volume of the working chamber. Larger pieces of material located closer to the peripheral part of the working area are subjected to more intense, not only cutting, but also impact impact of the blade blades. Small fractions of clay are crushed and cut with a knife closer to the shaft.

As a result of the above transformations, an increase in the productivity of the device and a qualitative improvement in the finished material were noticed at the output of the device.

The inventive stone extraction grate can be used for grinding, for example, in subsequent sections of the actuator, which will also increase the throughput of the device. In this case, the grill is set so that the bend of the holes is directed towards the rotating knife. In this case, the angle between the working edge of the knife and the partition it intersects will be sharp, less than 60 °, which will facilitate cutting.

Claims (4)

1. A device for grinding plastic materials, comprising a screw sequentially mounted in the housing and an actuator, including blade knives mounted on the shaft and alternating transverse grids fixedly mounted in the housing, with the first stone cutting knife and the grating located behind it made with slit-like holes directed from the center to the periphery, where at least part of the holes goes into the grooves to remove stones, characterized in that then the slit-like openings are curved along a curve close to the spiral, and made with expansion from the center to the periphery and along the thickness of the grating — in the direction of the product outlet, while the blade of the stone-cutting knife is made with a working face located tangentially relative to the shaft and forming tangent to any the partition it intersects between the lattice openings is an angle of 60 ÷ 90 °. 2. The device according to claim 1, characterized in that the working face of the stone-cutting knife is made with a bevel, which ensures the formation of an acute angle between this face and the surface of the stone-cutting lattice. 3. The device according to claim 1, characterized in that the stone-cutting knife is made of two-bladed. 4. The device according to claim 1, characterized in that the housing in the installation area of the stone-cutting pair is made with the extension.

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