RU2473421C1 - Method of forming man-made materials and roll press to this end - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to construction, particularly, to making compacted bodies from loose and viscous loose materials. Proposed method comprises several parallel stages of material compaction; at first stage, excess moisture is removed during loading by elastic rolls via webs of endless conveyor runs. Displaced material is divided into three flows, central flow and two lateral flows to compact material jaw compactor by pressure rolls and arc-like compactors leveling layer thickness over roll width.

EFFECT: decreased viscosity, increased initial density of material.

3 cl, 5 dwg

Description

The invention relates to methods for manufacturing pressed bodies from bulk and visco-plastic materials, in particular from production waste sold in press-roll aggregates, and can be used in various industries: building materials, chemical, energy, woodworking, and also in agricultural production.

There are various methods for the manufacture of compressed bodies obtained in press units, for example with preliminary compaction of the charge, applying binders to the surface of the rolls by irrigation and spraying on their upper part, heating the binder, etc. Patents No. 2185420, Mcl. C10L 5/44; publ. 07/20/2002; No. 2100204, Ml. B30B 11/00; publ. 12/27/1997.

However, the aforementioned pressing methods are not universal, which is especially important for the manufacture of briquettes from technogenic materials with a low bulk density: pulverization of drying and calcining units; ashes of thermal power station; waste of perlite, vermiculite production, woodworking industry, etc.

Closest to the proposed is the method described in ed. St. No. 742133, Ml. B28and 3/12, publ. 06/25/1980, according to which the pressing is carried out in a press-roll assembly using an increase in the initial bulk density of the mixture by means of vibration-absorbing action and its preliminary compaction by the roll method. However, this method does not allow to produce high-quality compressed briquettes from visco-plastic and moisture-saturated materials, thus it has limited technological capabilities due to the insufficient density of the material during its preparation, i.e. the method is also not universal.

There are also various units for the manufacture of compressed bodies (briquettes), for example, using preliminary compaction of the mixture: screw, roller and other prepress, for example patent No. 2028950, publ. 02.20.1995 g., Ml. B30B 11/26. In the aforementioned technical solution, local injection of the pressed material into the roll space of the press roll assembly is ensured, which does not allow uniformly distributing the material across the width of the rolls; or they do not provide the necessary coefficient of preliminary compaction of the mixture (the ratio of the density of the compacted material to its initial bulk density), which ultimately does not allow to obtain high-quality products (especially for technogenic materials with a low bulk density ρ ₀ ≤600 kg / m ² ).

The closest technical solution to the proposed is the prepress mechanism for the patent No. 213673, Mcl. B30B 11/18; B22F 3/02, publ. 07/27/1999, containing two parallel mounted cheeks with hollow housings connected in its lower part with traverses fixed in the central parts on the drive axles. The traverses, in turn, are pivotally connected to arcuate seals located above the pressing rollers.

However, this technical solution also has limited technical capabilities, is not universal and cannot be used for pressing technogenic materials with various physical and mechanical properties, for example, moisture-saturated materials (moistened cellulose-paper wastes, peat, shredded plant materials of agricultural production, moisture-resistant phosphogypsum and etc.), loose, low-flowing technogenic materials with a low initial bulk density (fine-grained woodworking waste minutes industry, thermally treated manmade materials - dust discharge drying and firing the aggregates of the cement and lime production, reducing its original bulk density due to hydration of CaO being in _{communication} mixture when it is wetted, highly porous materials, perlite and vermiculite waste production and etc.)..

The invention is aimed at solving the problem of expanding the technological capabilities of pressing mixtures with low bulk density, which consists in the possibility of pressing moisture-saturated and viscous-plastic materials by means of a press roll unit, as well as in expanding the range of materials used and improving the quality of the obtained products by ensuring a given density of the obtained briquettes and increasing productivity .

The specified problem is solved as follows.

When pressing products with the proposed method, designed for molding products from technogenic materials, consisting of several parallel stages of compaction in a jaw seal, when pressing products from low-flowing moisture-saturated materials: during the first stage, during the loading process, excess moisture is removed, and the material is simultaneously moved into three streams, then in parallel continue to produce compaction of the material moving further by discharge rollers and an arcuate seal carrier leveling the thickness of the layer across the width of the rolls, while if the material has excessive viscosity or low density, reduce and increase these indicators by vibration or heating.

To implement the described method, the press roll unit is equipped with a loading hopper composed of two vertically sequentially arranged blocks (in the upper of which there are a pair of elastic (rubberized) rollers, each of which is mated, with the possibility of changing the gap, with an endless branch, and in the lower block there is a jaw seal, the loading part of which contains hollow chambers, and the discharge part is connected to the bodies of the eccentrics. faces and connected in its turn to the arcuate seal secured to the side plates of the rolls).

The essence of the invention lies in the fact that low-flowing technogenic materials with a low bulk density are subjected to successive repeated pre-compaction in a press-roll assembly with a loading hopper, consisting of two blocks, one of which is equipped with a pair of elastic rollers mated to an endless branch, and in the second a jaw seal is installed with hollow chambers on the sides and connected to the bodies of the eccentrics, due to which a significant increase in the coefficient is achieved solid seal of the charge, its uniform distribution across the width of the forming rolls of the press-roll unit, which ultimately increases the productivity of the unit and the density of the formed briquettes. When molding technogenic materials with high humidity at the first stage (during the loading process), excess moisture is extracted by prepressing the material between the cylindrical surfaces of the elastic rollers and an endless branch, simultaneously with the prepress of the loaded mass, the material is divided into three streams, then the mass is further compacted in a jaw seal at the same time with discharge rollers and arcuate seals. With increased viscosity or low flowability of the material, it is heated by means of heating elements installed in the hollow chambers of the sealant and the side walls of the hopper, or by vibration exposure using vibrators placed on the side walls of the sealant.

The invention is illustrated in graphic materials.

Figure 1 presents a diagram of increasing the density of the compacted material according to the stages of its processing.

Figure 2 - General view of the unit for forming briquettes.

Figure 3 is a section along aa.

Figure 4 - view And on the inclined side surfaces of the hollow chambers of the jaw seal.

Figure 5 - view In on the attachment unit of the eccentrics to the jaw seal and discharge roller on the drive shaft of the device.

The press-roll assembly for molding technogenic materials contains two blocks 1 and 2 sequentially arranged vertically (FIGS. 2, 3). In the upper block 1, in a plane perpendicular to the axes of the rolls 3, 4 pairs of elastic (rubberized) rollers 5 and 6 are installed under the distribution plates 4. The distribution plates are installed horizontally at an angle β greater than the angle of repose of the material. Each of the rollers (5 and 6) is interfaced, with the possibility of changing the gap, with infinite branches (moving tapes) 7 and 8 of the loading device. In the lower block 2, in a plane parallel to the axes of the rolls, a jaw seal 9 is installed above them, the boot part of which contains hollow chambers 10 and 11 adjacent to the side walls of the hopper. The unloading part of the jaw seal is connected laterally to the bodies of eccentrics 12 and 13 (Fig. 3 eccentricity - e). The eccentrics are mounted on the shafts 14 and 15 of the discharge rollers 16 and 17 rigidly, with the possibility of transferring forces through the eccentric bodies to the cheeks of the sealant. The cases of the eccentrics 12 and 13 are connected by means of adjustable earrings pivotally sealed at the bottom of the arcuate seals 18 and 19. The hollow chamber of the screw seal in the upper part is connected using the earrings 20 and 21 to the walls of the hopper.

Above the jaw seal in the housing of the upper block on its sides (Fig. 3), movable gates 22 and 23 are fixed at an angle Ψ = 60 ° to the horizontal.

On the inclined side surface of the hollow chambers of the jaw seal, chevron-shaped protrusions 24 are installed, located at an angle γ = 45 ° to the horizontal (Figs. 2, 4). The discharge rollers 16 and 17, located between the eccentrics 12 and 13, are fixed on the drive shafts freely, with the possibility of rotation from external friction forces (figure 5).

In the hollow chambers of the jaw seal, on the side walls, vibrators 25 are installed, and on the vertical walls and in the side hollow chambers of the hopper, heating elements 26 are installed.

The method of pressing technogenic materials in a press roll unit is implemented as follows.

Technogenic material with a low bulk density, for example, dust extraction from cement, lime, perlite, and vermiculite production; wood processing industry wastes (sawdust) or moisture-saturated materials, such as phosphogypsum, peat, etc., with the initial bulk density p ₀ (Fig. 1), are loaded into the upper block 1 of the feed hopper, in which through distribution plates 4 (Fig. 2) ) it comes under elastic rollers 5 and 6, conjugated with endless branches - (moving tapes) 7 and 8. For uniform flow of material through the distribution plates, the angle of inclination to the horizontal must exceed the angle of repose of the loaded material, and for it evenly th distribution across the width of elastic rollers 5 and 6 are arranged on the working surface "elochnoobraznye" projections. The material moves in the directions K (Fig.2, 3).

After preliminary compaction of the material with elastic rollers, its density increases from ρ ₀ to ρ ₁ (figure 1). Identified empirically.

When using moisture-saturated materials and the force acting on them of elastic rollers, excess moisture is squeezed through the canvases of endless branches. The squeezed moisture is discharged through the side nozzles in the N directions (Fig. 2).

A pre-compacted material with a density ρ ₁ from the upper block 1 enters the lower block 2, while the material is not in a loose state with low flowability, but in the form of compacted plates with greater flowability.

Further, in the lower block, the material enters the jaw seal 9, which provides an increase in the density of the material from ρ ₁ to ρ ₂ (figure 1). The highest values are achieved in the parallelism zone of the jaw seal, in its lower part. To ensure uniform distribution of the compacted material across the width of the rolls 3 of the press roll unit, chevron-shaped protrusions located to the horizontal at an angle γ = 45-60 ° are located on the inclined surface of the jaw seal (Fig. 4). It was experimentally found that at γ <45 ° the required flowability along the protruding plates in the S directions is not ensured (Fig. 2), and at γ> 60 ° the material is concentrated in the central part of the rollers 5 and 6, not being distributed over their width. The movement of the seal cheeks along an ellipsoidal trajectory, which increases the flowability and compaction of the material, is achieved through the transfer of forces from the eccentrics 12 and 13. The latter are rigidly fixed to the drive shafts 14 and 15 and transmit the motion to it by means of eccentric housings mounted on the vertical walls of the jaw seal.

When using technogenic materials with a low bulk density, for example, perlite waste from the woodworking industry (sawdust), etc., separation of the material compacted in the upper block into flows is ensured:

I - the central, which feeds into the jaw seal, and two side - II and III.

The separation of the flows is carried out using the slide devices 22 and 23, mounted in the guides of the side walls of the hopper.

The angle of inclination of the gates to the horizontal is Ψ = 50-80 °. At Ψ <50 °, material hangs on gates, at Ψ> 80 ° the flow in directions II and III is limited (experimentally detected).

The material flows moving in directions II and III enter the sealing zones of the pressure rolls 16 and 17, which ensure the injection of the partially compacted material into the cells of the rolls 3 and its additional sealing (Figs. 3, 5) to a density ρ ₂ (Fig. 1) . The rotation of the rollers 16 and 17 is due to friction forces arising from the material being compacted between the rollers. The direction of rotation of the rollers 16 and 17 is opposite to the direction of the drive rolls 3 operating from the main drive. The seating of the sealing rollers on the supporting surfaces of the drive shafts 14 and 15 is sliding, which allows to provide the specified directions of rotation of the rollers 16 and 17. At the same time, the specified direction of rotation of the shafts 14 and 15 is from the additional drive and is opposite to the direction of rotation of the rollers 16 and 17. This ensures injection of material to be sealed in the jaw seal into the roll space (between the rollers 3) “from top to bottom” (Figs. 3, 5). Due to the parallel compaction of materials in the jaw seal (zone I) and discharge rollers (zone II and III), the material reaches a density ρ ₃ (FIG. 1). The presence of a jaw seal in its upper part of the hollow chambers 10 and 11 provides additional advantages:

- additional compaction of the material in the compartments during the movement of the cheeks, as well as the elimination of freezing of the material in the compartments;

- additional compaction of the material and optimization of its density and viscosity is achieved by vibration and thermal effects using vibrators and thermal heaters installed in hollow chambers.

The proposed design of the press roll unit allows you to expand its technological capabilities and implement the proposed method of pressing a wide range of technogenic materials.

The combination of the above technological methods: separation of the flows of movement of the mass of material, vibration, thermal heating, additional injection of material into the cells of the rolls and its compaction by rollers before feeding the material into the roll space allows to obtain an increase in the density of the material - dashed curve 2 in figure 1.

As a result of stepwise compaction of the material, the following technical results are achieved.

- The quality of the product’s seal is improved due to the fact that the material previously compacted in the upper part of the hopper, unlike loose, has greater mobility and ensures uniform distribution across the width of the working bodies (jaw seal, side compartments, working surface of the pressure rolls and press rolls). The required coefficient of preliminary compaction of technogenic materials is achieved before pressing them in the press rolls. The gaseous phase is removed from the powder material at the stage of its pretreatment, which eliminates the pressing of air into the pressed products and prevents the appearance of microcracks in them, which also favorably affects the quality.

- EFFECT: increased productivity of the press-roll aggregate due to increase in density and output of better briquettes.

- Technological capabilities (versatility) are expanding, consisting in the possibility of processing not only bulk, but also moisture-saturated, viscous-plastic materials, characterized by low flowability and increased adhesive ability (for example, waste from the woodworking industry - sawdust with oil bitumen binders for the production of alternative fuel sources - pressed pellets, for heating homes, heat generation of electric energy in autonomous heat and power generators). This is achieved through the use of vibratory devices and heat elements in the hollow chambers of the jaw seal.

- Strength properties of compressed bodies - (briquettes) increase due to obtaining a hardened surface layer during thermal heating of the pressed mass in zones II and III. Thus, the objective of the invention is solved.

Claims (3)

1. A method of molding technogenic materials, including several parallel stages of compaction, in the jaw seal, characterized in that during the preliminary compaction of the materials in the first stage, during the loading process, excess moisture is removed, then the material is divided into three streams and parallelly compacted the material in the jaw seal with discharge rollers and an arcuate seal that aligns the layer thickness with the width of the rolls, while reducing the viscosity and increasing the initial density nce material by heating or vibration feedback. 2. The press-roll assembly for implementing the method for forming technogenic materials according to claim 1, comprising a feed hopper mounted in the housing with the possibility of counter rotation of the rolls and a prepress mechanism made in the form of two hollow cheeks, with beveled working surfaces in the lower part that make up the jaw a gasket equipped with additional arcuate elastic gaskets mounted on the side plates of the rolls in the lower part, and in the upper part kinematically connected with the cheeks, characterized by that the loading hopper is made up of two blocks successively arranged vertically, in the upper of which, in the plane perpendicular to the axis of the rolls, a pair of elastic rollers is installed, each of which is coupled with the possibility of changing the clearance with an infinite branch, and in the lower block in a plane parallel to the axes rolls, a cheek seal is installed above the latter, the boot part of which contains hollow chambers located on the side walls of the hopper, and the discharge part on the sides is connected to the eccentric bodies s, rigidly fixed to the shafts of the discharge rollers, while the eccentric bodies are connected with the possibility of adjusting the gap with an arcuate seal, and the hollow chambers of the jaw seal are adjacent to the outer walls of the hopper, in addition, vibrators are placed on the side walls of the jaw seal, and the hollow chambers of the seal are installed heating elements. 3. The unit according to claim 2, characterized in that on the inclined surface of the jaw seal there are chevron-shaped protrusions located horizontally at an angle γ = 45-60 °, and the hollow chambers of the jaw seal are equipped with gate devices for overlapping the side compartments of the material loading, located in the plane of their inclined surfaces at an angle Ψ = 50-80 ° to the horizontal.

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