RU2304043C1 - Conveyer line for manufacture of cellular concrete articles - Google Patents

Abstract

FIELD: manufacture of building materials and cellular concrete articles.

SUBSTANCE: proposed conveyer line includes metering feeder, two-chain conveyer with L-shaped trays-sides mounted on it, longitudinal sides, vibrator, steel laminated electrodes for forced heating of mix, heat treatment chamber, drive and piler. Line is also provided with chamber for magnetic treatment of hardening concrete mounted behind the mix electric heating zone; its length ranges from 1.5-2.0 m and magnetic field intensity ranges from 10 to 12 kA/m. Proposed line enhances strength, durability and frost resistance by 15-20% and reduces duration of technological cycle, saves technological and operational expenses by 20% per cubic meter of product.

EFFECT: enhanced efficiency, strength and durability.

5 dwg

Description

The invention relates to the building materials industry, and in particular to equipment for the manufacture of small wall blocks of non-autoclaved aerated concrete, which can be used both for the erection of external walling and for providing thermal insulation of existing buildings and structures.

The technical result obtained by carrying out the invention is to optimize the substances of the cellular concrete mixture by adding additional processing of the mixture in the magnetic treatment chamber, which provides whiter high strength, durability, frost resistance by 15-20% [1], the duration of the technological cycle is reduced, due to this saving of technological and operating costs up to 20% per 1 m ^{3 of} finished products.

Closest to the claimed is a conveyor line for the manufacture of cellular concrete products [2]. Its disadvantages are: low strength, durability, frost resistance and increased heat treatment time of manufactured cellular concrete products, which leads to a decrease in the productivity of the conveyor line.

The problem solved by the invention is to increase the productivity of the conveyor line due to the magnetic treatment of hardening concrete, the intensification of the processes of structure formation.

To achieve the result provided by the invention, the conveyor line is equipped with a magnetic processing chamber for hardening concrete with a length of 1.5-2.0 m with a magnetic field of 10-12 kA / m.

The essence of the claimed invention consists of a magnetic treatment chamber for hardening concrete installed behind the zone of electric heating of the mixture.

The conveyor line for the manufacture of cellular concrete products contains a feeder-feeder, a double-chain carrier conveyor with L-shaped side pallets, longitudinal sides, a vibrator, a magnetic processing chamber and a heat treatment chamber mounted on it, a drive and a stacker of products.

The chamber of magnetic processing of hardening concrete 1.5–2.0 m long with a magnetic field strength of 10–12 kA / m installed behind the zone of electric heating of the mixture is new.

L-shaped pallets-sides are made of fiberglass, fixed steel longitudinal sides in the pouring and swelling zone of the mixture are simultaneously plate electrodes for forced electric heating of the mixture, and in the initial zone of the heat treatment chamber, the longitudinal sides are made of fiberglass, and in the zone of electric heating of the mixture and the initial zone of the chamber a fiberglass pressure shield is installed above the compartments of the conveyor to seal the hump and form a concrete structure in a closed volume. The pressure shield is spring-loaded with elastic gaskets and insulated outside the chamber. The vibrator is mounted on the conveyor frame in the mixture filling zone. The heat treatment chamber is equipped with electric heaters.

Figure 1 shows the proposed line, a General view; figure 2 is the same plan; figure 3 is a section aa in figure 1; figure 4 is a section bB in figure 1; figure 5 - section bb in figure 1.

The conveyor line consists of a feeder-feeder 1 for the portioned supply of aerated concrete mixture into the compartments (cells) of the conveyor, a double-chain carrier conveyor in the form of connecting plates 2, pivotally connected to the rollers 3, drive sprockets 4, tension sprockets 5, guides 6, the drive in the form of an electric motor 7 and gearboxes 8.

The guides 6 and racks 9 constitute the supporting frame of the conveyor. L-shaped fiberglass (dielectric) side pallets 10 using holders 11 and bolts 12 with fiberglass bushings and washers are rigidly fixed to the shafts 13 of the conveyor. Steel plates-electrodes 14, which serve for electric heating of the mixture, are simultaneously longitudinal sides, forming compartments for products, and are mounted on brackets 15 with bolts 16, insulated with fiberglass bushings and washers from metal parts of the conveyor. The plate-electrodes 14 contain terminals 17 for connection with current-carrying wires coming from a step-down transformer 18.

A vibrator 19 is installed on the conveyor frame in the pouring zone of the mixture. The conveyor line is equipped with a fiberglass clamping plate 20, which is fixed to the brackets 21 and insulated from above by a heater 22. The shield 20 is spring-loaded on the brackets 21 with elastic gaskets 23. The clamping plate 20 is located above the conveyor compartments in the magnetic zone processing and electric heating of the mixture, then in the initial zone of the magnetic processing chamber of the mixture 24 and creates a closed volume compartment in this section of the conveyor. The plate-electrodes 14 in the initial zone of the chamber 24 are continued with fiberglass boards 26, also to create a closed volume of the compartments.

The heat treatment chamber 25 is equipped with electric heaters 27 and is insulated from the environment by heat-insulating plates 28, 29. The entrance to the chamber 24 and the exit from the chamber 25 are covered with shutters 30. The line contains a storage table 31 for stacking products (the stacker is not shown).

The line works as follows.

The electric heaters 27 are preliminarily switched on, and the temperature in the chamber 25 rises to the set one. After turning on the drive of the conveyor, portions of the ready-mixed concrete mixture of a given constant volume (mass) are poured through the batcher-feeder 1 into the compartments (cells) of the conveyor at the moment of passage of the next compartment under its neck.

To evenly distribute the mixture in the compartments after filling each portion of it by 3/4, the vibrator 19 is automatically turned on. The second, more important, function of the vibrator 19, the effect of which extends to the zone of magnetic processing and electric heating of the mixture, is that during periodic vibration stress relieving (relaxation) in the mixture expanded upon heating, which improves the physicomechanical properties of concrete. Vibration parameters (amplitude, frequency) are assigned depending on the elastoplastic properties of the mixture.

The electrode plates (longitudinal sides) 14, which are under alternating current voltage, have a length corresponding to a predetermined time (3-5 minutes) of forced heating of the mixture due to its electrical conductivity from an initial temperature of 20-30 ° C to 90-100 ° C. Accordingly, the speed of the conveyor (5-15 mm / s) and voltage (36-127 V) are calculated and set. The indicated parameters are also determined depending on the electrical resistivity of the mixture (type and composition of cellular concrete). The length of the conveyor is determined depending on the required (given) strength of concrete at the time of removal of products from the conveyor, as well as on the intensity of hardening of concrete.

The compartments are filled with the mixture at the filling station to a predetermined (incomplete) height, and during electric heating it swells up (with the option of the foam method of porosity due to the thermal expansion of air bubbles, with the variant of the gas method of porosity additionally due to the chemical reaction of gas formation). In the position of the compartments in front of the pressure shield 20, a hump is formed above them (excess swollen mixture).

With further movement of the compartments with the mixture, crushing of the humpback with a shield occurs and smoothing of the faces of the blocks facing it. Since at the moment the compartments enter under the shield 20, the processes of gas formation and thermal expansion of gas (air) bubbles in the mixture still do not end, these processes are carried out in conditions of closed volume of the compartments. The overpressure created in this mixture in the mixture has a positive effect on the formation of the structure and properties of cellular concrete. A layer of compacted and smoothed-out hump (thickness 3-5 mm) performs protective and decorative functions during the operation of the products.

Rubber gaskets 23, spring-loaded pressure shield 20, firstly, reduce the friction of the shield on the surface of the products and, secondly, help to equalize the pressure in the mixture in different compartments.

The compartments with the mixture at the time of reaching the maximum temperature (90-100 ° C) pass through the magnetic treatment chambers 24 and enter the heated heat treatment chamber 25, the medium temperature in which is close to or identical with the temperature of the mixture, which is one of the factors ensuring the operability of the conveyor (in addition to important technological factor that improves the properties of the material). In this case, the total length of the pressure shield 20, as well as the lateral (longitudinal) electrode plates 14 and fiberglass boards 26 is determined by the mixture heating rate and the time required for concrete to acquire plastic strength sufficient for further transportation of the products along the conveyor without breaking on the pallets 10 .

The formation of the structure of cellular concrete before acquiring this strength in the manufacture of products on the proposed line takes place when three faces of the products (two side and top) slide on the surface of the structural elements of the conveyor. This fact eliminates the need for lubrication of these elements (shield 20 and sides 14, 26). The lack of adhesion of concrete to fiberglass also excludes the operation of lubricating the pallets-sides 10. However, due to the abrasiveness of the concrete components after a certain number of revolutions (100-150) of the pallets 10, their surface becomes rough. To prevent adhesion of the mixture and concrete, it is necessary periodically after cleaning the surface of the pallets 10 to apply a thin layer of hardening coating of synthetic resin to it.

At the stripping station, the product is pushed (not shown) to a storage table 31, from which they are removed by a stacker (not shown).

In the gap between the drive sprockets 4 of the conveyor and the floor is a special mobile cleaning mechanism for the pallets-sides 10 (not shown).

On the proposed conveyor line, it is possible to produce heat-insulating and structural-heat-insulating products with increased compressive strength from non-autoclave foam and aerated concrete compared to the prototype by 5-10% and productivity up to 20%.

Information sources

1. Udachkin NB Scientific and technical activities and the development of the cement industry in the context of new forms of management // Cement, No. 1-2, 1991. S. 7-8.

2. RF patent No. 2056282, cl. B28B 5/02, 1/50, BI No. 8, 1996 (prototype).

Claims (1)

A conveyor line for the manufacture of cellular concrete products, containing a batcher-feeder, a double-chain carrier conveyor with L-shaped pallets-sides installed on it, longitudinal sides, a vibrator, steel plate electrodes for forced heating of the mixture, a heat treatment chamber, a drive and a stacker, characterized in that the line is equipped with a magnetic treatment chamber for hardening concrete installed behind the zone of electric heating of the mixture, 1.5-2.0 m long with a magnetic field strength of 10-12 kA / m.

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