RU2470776C2 - Activator and method of its application - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of mortars. Proposed device comprises housing, communication pipes, drain branch pipe, drive vaned rotor, discs arranged one above the other and aligned to make the set of alternating grinding rotary and stationary discs with compression springs fitted on pins between said discs. Rotary grinding discs have their slots engaged with rotor vanes. Ledges of stationary discs are engaged with housing. Extreme stationary disc of said set is thrusted by flexible pressure element with union to feed compressed air. Continuous-action plant for making heavy concrete and nano-concrete comprises bins for crushed stone, coarse and fine sand, fine sand screw feeder, cement feed system, water and ground sand feed system, weight proportioner with strain gages, cyclic mixer, intake bin of hydraulic concrete pump, two above described activators and two cyclic mixers. Bins of crushed stone, coarse and fine sand are communicated with said proportioner, its outlet branch pipe being communicated via gate with both mixers. Outlet branch pipes of cyclic mixers are connected with hydraulic pump bin. Cement, ground sand and water feed systems are communicated with activators while activator drain branch pipes are connected with cyclic mixers arranged there under.

EFFECT: perfected design.

5 cl, 6 dwg

Description

The invention relates to grinding equipment and is intended for wet activation of cement paste, as well as for bringing grains of cement and ground sand to a nanosize of the order of 100-200 nm, necessary for the preparation of concrete mixtures, nanobeton, foam concrete, nanofoam concrete.

There is a method of separate technology for the preparation of concrete mix (S. Ataev, "Technology of industrial construction from monolithic concrete", Moscow, "Stroyizdat", 1989). This technology for producing concrete mix allows to save cement by 25-30%. The mechanism of saving cement is explained by the fact that in the process of preparing a concrete mixture, due to incomplete hydration, up to 30-50% of cement grains are used as a regular finely ground inert filler. That is, when preparing the concrete mixture in the usual way, part of the cement grains does not mix with the rest of the ingredients and forms "flocs", which is economically disadvantageous and reduces the quality of the concrete mixture. If you replace this part of unhydrated grains with another fine-ground filler with the addition of some part of ordinary silica sand, you can save the corresponding amount of cement.

Planetary mills, which are high-voltage grinding equipment, are presented on the Russian market. For example, CJSC Activator mastered the production of planetary ball mills Activator, (WWW.activator.ru, 630056, Russia, Novosibirsk 56, PO Box 141). "Activator" is a series of high-speed planetary mills with different capacities, designed specifically for scientific research and production. In such mills, there are usually 3-4 discs installed in the housing. Communication pipes for feeding ingredients are brought to the mill. The disks are connected with the rotor of the drive and rotate around the central axis and simultaneously around their own axes in the opposite direction (similar to the movement of the planets around the sun). In this case, the particles of the crushed material undergo many collisions with the grinding bodies and the walls of the drum. At high accelerations of rotation of the drums, as a result of intensive machining, particles are crushed, and the physicochemical properties of the obtained powders change. Such mechanically activated powders have a high reactivity and enter chemical reactions more easily.

The drawback of ball and other types of mills is that the nanopowders obtained by grinding with a particle size of less than 100 nm are extremely inconvenient to use: they occupy a large volume, dust when working with them and form a fairly stable suspension, their effect on human health has been little studied . The grinding process is carried out in dry form (dry grinding), which is accompanied by the release of a large amount of heat during friction; therefore, a cooling system should be provided in the mills. Since mills are structurally complex autonomous devices, the finished product must be delivered to the consumer, and in the meantime, the shelf life of the nanopowder is limited (no more than 3 months). After its expiration, re-grinding is required.

Known cyclic dish-type mixers SB-142 or SB-133 (K.M. Korolev. "Mobile concrete-mortar and concrete pumping plants", Higher school, Moscow, 1986, p. 36). Mixers consist of a bowl (body), paddle mixing mechanism, gearbox and drive. The constituent mixtures are loaded in separate portions through an opening in the lid. The disadvantages of these mixers are the cyclical nature, incomplete hydration of cement grains, the inability to obtain nanoscale grains of cement and, as a consequence, the inability to obtain nanoconcrete.

The technical task of this invention is divided into technologically related tasks:

1. The creation of the design of the activator to obtain activated cement paste from cement and ground sand in the presence of water with bringing their particles to nanoscale sizes of the order of 100-200 nm.

2. Creating a continuous installation for the preparation of heavy concrete and nano-concrete using an activator in its design. Moreover, the design is based on the technology for separate preparation of concrete mix described above. In this case, maximum hydration of the cement paste is achieved.

To achieve this goal, an activator of a special design has been created. The function of the activator is to obtain a cement paste from cement particles ground to nanoscale and ground sand in a medium of water (wet grinding).

The activator includes a set of coaxially mounted rotating and fixed disks. Rotating grinding discs with their grooves are mounted on the rotor blades, and stationary grinding discs with protrusions are fixed. Each grinding disc is provided with rings on one or two sides. Radial channels are made on the rings, expanding toward the center of the disk. The material of the rings can be an abrasive with a smaller structure, diamond rings with a structure of 4-60 microns, self-grinding metal-ceramic rings with a special relief, etc., which greatly increases the life of the activator.

The design of the activator and its applications in various devices are shown in the drawings.

Figure 1 shows the assembly drawing of the activator.

Figure 2 shows the assembly drawing of a set of grinding discs.

Figure 3 and 4 shows the design of the rotating and stationary grinding disks of the activator.

Figure 5 shows the design of a continuous installation for the preparation of heavy concrete and nano-concrete using an activator.

The activator (see Fig. 1) includes a set of 1 alternating grinding rotating and fixed disks installed in the housing 2 (the Set is installed with a stationary grinding disk down), and a drive 3 with a rotor 4 equipped with blades 5. Communication pipes 6 are connected to the activator housing 2 , 7 and 8 for the supply of cement, ground sand and water. A drain pipe 9 is installed at the bottom of the body. Pipes 6, 7 and 8, as well as a drain pipe 9 are equipped with automatic gates (not shown in the drawing). The extreme stationary grinding disc of the kit (in this case the lower one) is supported by a flexible clamping element 10 (for example, a rubber hose), into which compressed air is supplied through the nozzle. The set of grinding discs 1 is fixed to the housing 2 with jibs 11, provided with grooves 12. The set of discs (Fig. 2, in the drawing is rotated 180 °) includes coaxially milled rotating 13 and stationary 14 discs. Between the disks on the pins 15, compression springs are installed 16. The rotating grinding disk is provided with a groove 17 from the inside, and the stationary grinding disk is provided with an overhang 18 on the outside. Each grinding disk is provided with rings 19 on one or two sides. Radial channels 20 are made on the rings and extend to the center of the disk . The material of the rings can be an abrasive with inclusions of diamond chips, cermets, etc., which will significantly increase its abrasion resource. In the initial position, the disks 13 and 14 of the set 1 under the influence of the efforts of the springs 16 are removed from each other, i.e. between the adjacent disk rings a small gap is formed, sufficient for the unimpeded circulation of the particles of the ingredients of the prepared mixture. When compressed air is supplied to the flexible pressing element 10, it is inflated and presses against each other the surfaces of the rings 19 of adjacent disks. In this case, the upper stationary grinding disk in the set 1 abuts against the cutouts of the blades 5 (not visible in the drawing), providing a clamp. Between the flexible clamping element 10 and the bottom of the housing 2, as well as between the set of disks and the inner wall of the housing, a gap is provided to ensure circulation of the prepared mixture. The blades 5 of the rotor 4 enter the grooves 17 of the rotating grinding disks, and the protrusions 18 of the stationary grinding disks enter the grooves 12 of the jib 11. Thus, when the rotor 4 is rotated, the disks 13 rotate and the disks 14 remain fixed. The activator works as follows.

To prepare a conventional cement dough, the rotor 4 of the installation is rotated and fed into the housing 2 through the pipe 8 with the gate open, the calculated portion of water. After this, the gate is closed, and in the same way a portion of cement is fed through the pipe 6 and 7 and, after activation, ground sand is fed. Next, cement and sand are mixed together with water, forming a cement paste. After a predetermined time of rotation of the rotor, the finished cement paste through the drain pipe 9 is fed to the destination for use or to continue the process. For example, they are fed to other plants for foam concrete, nanofoam concrete, ordinary concrete or nanobeton, etc.

To prepare the nano-cement dough, they perform the same steps as for the preparation of a conventional cement dough, but supply compressed air to the flexible pressing element 10 (hose). A flexible clamping element is inflated and presses against each other the surfaces of the rings 19 of the adjacent disks, overcoming the resistance of the springs 16. In this case, the blades 5 mix the ingredients, forming a cement paste, which, under the influence of centrifugal forces of the rotating rotor 4 and the blades, rises along the inner wall of the housing 2 and enters the internal cavity of the set of disks 1. From there, the cement paste enters the radial channels 20 and, falling between the friction surfaces of the rings 19, is ground to the required nanoscale. The amount of cement dough ground to nanoscale is determined empirically and depends on the volume of the mixture being prepared, the pressing force of the disc rings, the duration of rotation, the number of discs, rotor speed, etc. After reaching the desired parameters of the nano-cement test, air is blown out of the hose 10, the springs 16 move apart the disks. The grinding process stops.

The continuous installation for the preparation of heavy concrete and nano-concrete (see Fig. 6) includes a weight batcher 27, activators 28, a crushed stone hopper 29, coarse sand hopper 30, cyclic mixers 31, 32 and a receiving hopper 33 of a hydraulic concrete pump. The dispenser and activator are equipped with strain gauges. Two cyclic mixers are used to ensure continuous production of concrete. The bins 29 and 30 are equipped with automatic gates 34 and 35 for feeding crushed stone and coarse sand. The dispenser 27 is equipped with a switching gate 36, designed to send measured by weight portions of gravel or sand in a 31 or 32 cyclic mixer. 37 - hopper for fine sand. Ready concrete from the mixers through the open gates of the outlet pipes (not shown in the drawing) is poured into the receiving hopper 33 and from there it is fed to the destination. To the housing 2 of the activator (see figure 1) summed up pipes 6, 7 and 8 for supplying, respectively, cement, ground sand and water. The pipes at the entrance to the activator are equipped with automatic gates and a valve. The drain pipes of the activators are equipped with gates (not shown in Fig. 6), through which cement paste prepared in the activators is supplied to the cyclic mixers placed under them.

Installation for continuous operation for the preparation of heavy concrete and nano-concrete works as follows.

Crushed stone and coarse sand from the bins 29 and 30 fall into the weight batcher 27 by alternately opening the gates 34 and 35. Fine sand is fed from the separate hopper (not shown) by a screw feeder there. Loading and total weighing of the dispenser is carried out according to the program, depending on the concrete received. Through pipes 6 in the case of the activator 28 serves cement. Then, in the presence of water, with stirring, the wet activation of the cement paste is carried out to nanoscale. Next, ground sand (20-70 μm) is fed through the pipes 7 to the activator and the resulting cement paste with ground sand and plasticizing additives is activated, which makes it possible to intensify the grinding and activate the surface of the filler particles. At the same time, particles of ground sand by grinding are also brought to nanoscale. The activated nanocement dough thus prepared from the activator is discharged through a drain pipe with an open lower gate (not shown in the drawing) into the downstream cyclic mixer 31. Fillers from the dispenser 27 are then unloaded there. The concrete mix prepared in the mixer is discharged into the downstream hydraulic concrete receiving hopper 33 . At the same time, according to the technology described above, the next batch of concrete mix is being prepared in the mixer 32 by the time the concrete is pumped from the hopper 33 of the concrete pump. Thus, using two batch mixers, a continuous process for preparing a nano-concrete (concrete) mixture is ensured. Ready concrete (nano-concrete) mix is fed from the receiving hopper to its destination.

Claims (5)

1. The activator, comprising a housing, communication pipes, drain pipe, disks, rotor drive with blades, characterized in that the disks are mounted coaxially above each other and form a set of alternating grinding rotating and fixed disks, between which compression springs are mounted on the pins, while the rotating grinding discs are engaged with their grooves with the blades of the drive rotor, and the stationary grinding discs are engaged with their projections on the housing, the extreme stationary grinding disc of the set being supported by a flexible clamping element with Utsera for supplying compressed air. 2. The activator according to claim 1, characterized in that the grinding discs are provided with rings on the surface of which radial channels are made, expanding toward the center of the discs. 3. The activator according to claim 2, characterized in that the rings are made of abrasive material with inclusions of diamond chips or cermet. 4. The activator according to claim 1, characterized in that the extreme rotating disk of a set of alternating grinding rotating and stationary disks is facing the rotor. 5. A continuous installation for the preparation of heavy concrete and nano-concrete, including hoppers for crushed stone, coarse fine and ground sand, a screw feeder of fine sand, a cement, water and ground sand feed system, a weight batcher with load cells, an activator, a batch mixer, automatic gates , a receiving hopper of a hydraulic concrete pump, characterized in that it contains two activators, made according to claim 1, and two batch mixers, and the hoppers of crushed stone, coarse and fine sand are connected to the dispenser, the outlet pipe of which is connected through the gate to both mixers, and the outlet pipes of the cyclic mixers are connected to the hopper of the hydraulic pump, the cement, ground sand and water supply systems are connected to the activators, and the drain pipes of the activators are connected to the cyclic mixers located below them.

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