RU2347167C2 - Clayware kiln - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention relates to kilns for clayware, mainly bricks. The kiln comprises a lined bulk, conveyors, loading and unloading devices, heating devices. The conveyors are made as frameworks for products, they are connected to each other by chain links which are coupled to the stars on the drive shafts fixed on the bulk bearing beam. The conveyors are mounted vertically in rows within the whole kiln volume. Each row consists of several conveyors mounted on a separate shaft which is fixed on the bearing beam. Loading and unloading devices are made analogous to the kiln conveyors and are placed on the shaft of each conveyor row at the input and output of the kiln. A pusher which can be moved back-and-forth is mounted before a loading device at the level of each upper row of frameworks. The heaters are placed on the kiln bulk floor on both sides of the conveyors in each row. Air ducts are mounted in the upper kiln part on both sides of the conveyors in each row.

EFFECT: high reliability of the kiln operation.

3 dwg

Description

The invention relates to kilns for firing ceramic products, mainly for firing bricks.

Known furnace described in the patent of the Russian Federation No. 2105257, class. F27B 9/02.

The furnace is a single-channel heat-insulated tunnel with two ends at the ends of the tunnel. There are several zones along the length of the tunnel, with a brick burning zone in the middle, and heating-cooling, loading-unloading zones symmetrically located to the left and right of it, and the heating-cooling zones in general consist of drying zones and heating-cooling proper. Electric heaters are located inside the firing zone to create a temperature of about 900-1000 ° C in this zone and to burn bricks laid in several continuous rows several bricks high. In this case, there are no partitions between the rows, and any two adjacent rows move on the conveyors in opposite directions, i.e. half of the bricks loaded in the kiln move in one direction, and the other in the opposite direction, and in a straight line. In practice, this nature of the movement of bricks can be accomplished by using two independent drives. At each end of the tunnel furnace, bricks are loaded only simultaneously, laying bricks in rows that move in the direction of the firing zone, and unloading from those rows that move from the firing zone.

The disadvantages of the furnace are:

- inefficiency of using the surface of the brick in heat transfer during firing and drying due to the laying of bricks on each other;

- uneven heating of bricks due to laying it in vertical rows;

- use for heating bricks only electric heaters;

- low productivity of the furnace due to its small volume;

- bilateral loading and unloading of bricks;

- lack of ventilation, adversely affecting heat transfer.

Closest to the proposed is a kiln for firing ceramic products, mainly building ceramics (RF patent No. 2027965, class F27B 9/02), containing a lined body, parallel channels arranged in several rows, with heating, firing, cooling zones and with the possibility of moving products in adjacent channels in opposite directions, conveyors, heating devices, loading and unloading devices installed from both ends of the furnace; the channels are separated from each other by non-continuous partitions and are arranged in several rows along the height and (or) along the width of the furnace, non-continuous partitions separating the channels are installed in contact with products or flaps moving along the channel with products of one or both channels. The disadvantages of the furnace are:

- insufficiently high reliability of the furnace due to bending loads on the conveyor parts during operation of the furnace, splinters of brick falling onto the conveyor rollers;

- use for heating bricks only electric heaters located in the rollers themselves or between them, which overheat and fail due to the presence of dust from the brick;

- bilateral loading and unloading of bricks;

- lack of ventilation, adversely affecting heat transfer;

- the technical complexity of operation due to the presence of roller conveyors with a large number of rollers, which often fail due to high temperatures, dust, fragments of brick and require a systematic straightening.

The objective of the invention is to increase the reliability of the furnace.

The task is achieved in that in the kiln for firing ceramic products containing a lined body, devices that are in contact with moving products with the ability to move in rows of the working volume of the furnace along the height of the furnace and having directions of movement in adjacent rows towards each other, conveyors, loading and unloading devices, heating devices, according to the invention, the conveyors are made in the form of frames for products, interconnected by chain links that are hooked laziness with asterisks located on the drive shafts, mounted on the supporting beams of the housing with rotation; conveyors are arranged vertically in rows along the entire working volume of the furnace, each row includes conveyors located on a separate shaft mounted on a carrier beam with rotation; loading devices are located at the inlet of the furnace, and unloading devices are located at the outlet of the furnace; a pusher is mounted in front of the loading device at the level of each upper row of frames, mounted on a supporting beam with the possibility of reciprocating movement along a number of frames; heating devices are located on the floor of the furnace body on both sides of the conveyors of each row, and in the upper part of the furnace on both sides of the conveyors of each row there are air ducts with holes on the side walls.

This embodiment of the device makes it possible to eliminate bending loads on the parts of the conveyor during the entire cycle of heat treatment of bricks, which significantly increases the reliability of the furnace.

Figure 1 shows a longitudinal section of a furnace;

Figure 2 - section aa (cross section of the furnace);

Figure 3 is a fragment of the conveyor in an enlarged view.

The brick kiln (FIG. 1, FIG. 2) has a lined casing, consisting of load-bearing beams 1, columns 2 and insulation 3. Inside the furnace casing, furnace conveyors 4 are located throughout the furnace’s working volume. Conveyors are made (FIG. 3) in the form of brick frames 5, interconnected by chain links that are meshed with sprockets 6 located on drive shafts 7, mounted on carrier beams 1 of the housing on bearing bearings. The shaft 7 is driven by a drive 8. The conveyors 4 are arranged vertically in rows (Figure 2) throughout the working volume of the furnace. Each row (Figure 1) includes conveyors 4 located on a separate shaft 7, mounted on a supporting beam 1. In front of the loading device 9, a pusher 11 is mounted at the level of each upper row of frames, mounted on the supporting beam 1 with the possibility of reciprocating movement along a row frameworks. The loading device 9 has a separate drive 12 and drive sprockets 14. The unloading device 10 has a separate drive 13 and drive sprockets 15. Heating devices 16 are located on the floor of the furnace body on both sides of the conveyors 4 of each row. In the upper part of the furnace, ducts 17 with openings on the side walls are arranged in tiers on both sides of the conveyors of each row. The furnace operates as follows.

In the initial state, the frames of the furnace conveyors 4 are empty. The brick is loaded into the upper frames of the furnace conveyors. The furnace conveyors are stationary during loading. The drive 12 of the loading device rotates the sprockets 14 by one step. Thus, the raw brick moves piece by piece up. After each step, the pusher 11 is activated, which moves the raw brick from the upper frame of the loading device through the platform or the intermediate roller table to the upper frame of the first furnace conveyor. When all the upper frames of the furnace conveyors are filled with raw material, the drive 8 is turned on, which, with the help of the shaft, rotates the sprockets 6 of the furnace conveyors by one step.

Thus, the raw brick goes down to the furnace, where it enters the convective drying zone formed by the air ducts 17. A temperature and humidity are maintained in each tier of the air ducts in accordance with the technology. These ducts also serve to remove fumes and gases from the furnace.

As it moves down, the brick dries, heats up. The brick reaches the highest temperature at the very bottom of the furnace, where firing takes place. After that, the brick rises. In this case, a brick moving upwards gives off heat through radiation and convection to bricks moving down. The direction of gas movement between the ducts periodically changes. For the separation of zones with predominant convection and predominantly radiant heat transfer, dampers 18 are used. When the fired cooled brick is at the top, that is, in the upper frames of the furnace conveyors, the fired brick is replaced by raw material by pushing it in the direction of the unloading device 10. After each reciprocating movement of the pusher 11 in the upper frame of the unloading device is burnt brick. After that, the drive 13 of the discharge device rotates the sprockets of the discharge device one step. Thus, the burnt brick moves step by step down.

The advantage of the invention in comparison with the known are:

- improving the reliability of the furnace by eliminating bending loads on the parts of the conveyor during the entire cycle of heat treatment of bricks;

- simplification of the operation of the furnace due to the exclusion from the heat treatment zone of roller conveyors with a large number of rollers, which often fail due to high temperatures, ingress of brick fragments and require systematic straightening;

- the use for heating bricks not only electric, but also other types of heaters, for example, gas;

- simplification of loading and unloading of bricks due to the location of the loading and unloading devices on opposite sides of the furnace;

- the presence of ventilation, positively affecting heat transfer.

Claims (1)

A kiln for firing ceramic products containing a lined body, devices that are in contact with moving products with the ability to move in rows of the working volume of the furnace along the height of the furnace and having directions of movement in adjacent rows towards each other, conveyors, loading and unloading devices, heating devices, characterized in that the conveyors are made in the form of frames for products, interconnected by chain links that are engaged with sprockets located on -period shafts fixed to the carrier beams body rotatably; conveyors are arranged vertically in rows along the entire working volume of the furnace, each row includes conveyors located on a separate shaft mounted on a carrier beam with rotation; loading devices are located at the inlet of the furnace, and unloading devices are located at the outlet of the furnace; a pusher is mounted in front of the loading device at the level of each upper row of frames, mounted on a supporting beam with the possibility of reciprocating movement along a number of frames; heating devices are located on the floor of the furnace body on both sides of the conveyors of each row, and in the upper part of the furnace on both sides of the conveyors of each row there are air ducts with holes on the side walls.

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