Production of bricks: equipment, technology
For many centuries, the history of building materials brick has established itself as a reliable universal material. The latest developments in the field of construction are not able to completely oust the brick from the market, and this situation will continue for a long time. Brick is great for the construction of capital buildings and structures due to its properties. The production of bricks from clay has not undergone significant technological changes over the past few centuries, but other methods have emerged for the manufacture of blocks for brick masonry. Among them, the most popular are the production technology of silicate bricks, as well as the use of high pressure as an alternative or addition to firing.
Types of bricks and their characteristics
Bricks are called solid blocks for laying structures of certain sizes. With a large deviation from the standards of length, width and height, the products are already called simply building blocks.A single, simple Russian-made brick is produced with a length of 250 mm, a width of 120 mm and 65 mm in height, there are also one-and-a-half and double variants with a height of 88 and 138 mm, respectively. Europe has adopted its own standard brick sizes, which is associated with the historical development of the measurement system. The material for the manufacture of bricks can be a large number of loose and crushed substances, but the most popular are clay and sand with lime. This is reflected in the name of the blocks; red ceramic bricks are made almost entirely of clay, while the production of silicate bricks is based on a mixture of sand and lime. Characteristics of such material are somewhat lower than ceramic, which is compensated by a relatively low price. The third type of hyperpressed blocks can consist of various materials, depending on the characteristics planned by the manufacturer. All three major types are subdivided into a large number of subtypes with different properties and uses.
Methods for the production of bricks vary, depending on the raw materials used.The technology for the production of bricks from clay using high-temperature calcination has remained unchanged for several thousand years, while the manufacture of silicate bricks began only at the end of the 19th century. Silicate brick does not require firing, as ceramic, instead, the mixture is exposed to water vapor under high pressure. Hyper presses for the manufacture of brick blocks generally arose relatively recently, this method does not use the effect of high temperatures in the formation of solid material. Nevertheless, hyper-pressed bricks are not inferior in their properties, and often surpass their “ancient brethren”. Experts compare this material with high-quality clinker bricks.
Ceramic brick production
Equipment for the production of bricks from clay by plastic or semi-dry methods should include the following mandatory units and rooms:
Raw material warehouse, where the clay is pre-“caked out” to the desired degree of moisture. It is also possible to add butiruyuschego material, sand or broken brick, in an amount of not more than 30%.Such additives allow the raw material to keep its shape easier and reduce the deformation during temperature processing.
The site of grinding and mixing of raw materials may include several devices for the gradual filtration, crushing and creating a homogeneous mass. For the ductile method, add installations of processing clay with water vapor.
The formation of raw products involved in the device based on vacuum or hydraulic presses. These devices produce a strip for cutting, from which raw brick is already formed. Compact garage and home-made options can form finished piece products without the need for cutting, but the speed of such installations is extremely small.
Furnaces for drying raw and roasting produce two types: chamber and tunnel. The second option requires solid construction, but allows streaming non-stop production. The semi-dry method of forming raw material can save drying time. Standard firing temperature for ceramic blocks is 1000
Warehouse of finished products, where baked bricks are received for storage and sale.
Transportation units between installations of varying degrees of mechanization of labor, from manual to conveyor type.
In the construction of furnaces and other refractory surfaces the use of ordinary bricks is unacceptable. Silicate brick is not able to withstand even the temperature of a conventional firewood burning flame, and a simple ceramic block loses its strength properties at temperatures above 800. Yes, and constant temperature fluctuations adversely affect the properties of ordinary bricks. Requires a material that can withstand periodic strong heat and subsequent cooling over a long period of operation. One of the most popular refractory materials is chamotte brick, the manufacture of which is based on the production of bricks from special clay - chamotte. Equipment for the production of bricks from it is similar to that described above, but the distinctive features of the technology of production of conventional ceramic blocks are two stages:
In the preparation of raw materials, refractory clay undergoes preliminary high-temperature processing, in order to improve the refractory properties of the finished product, mineral additives, in particular aluminum oxide, are used.
Raw firing does not occur at 1000and at 1500 and above, the firing time is at least 5 hours.At such temperatures, sintering of the material and transformation of the chemical composition as a whole takes place.
The chamotte brick porosity determines its strength and thermal insulation properties.
Facing walls and other structural elements is not only a beautiful appearance of the material, but also its resistance to weathering and mechanical damage. Manufacturers of bricks since the 18th century produce a particularly durable material, comparable in wear resistance to natural stone. The name came from German for the resonant response of a brick when tapping, this is not surprising, because the clinker blocks are one of the most dense materials in their class. Clinker brick production places high demands on the quality of raw materials, requires monitoring the content of oxides of iron, calcium and magnesium, as well as a sufficient content of aluminum oxide. The firing temperature of the cladding material according to this technology is 1000-otherwiseProduction technology repeats the method of obtaining conventional ceramic bricks.One of the main disadvantages of clinker ceramic blocks is their good thermal conductivity, therefore, when facing the external walls of a building, additional thermal and acoustic insulation may be required. The bricks of this technology are produced in the most diverse designs,including with voids to the rearnoodles and glaze on the front.
Silicate brick production technology
The process of the formation of solid blocks from a mixture of lime and sand is based on the heat treatment of the finished solution and has emerged relatively recently, whereas the use of the mixture in construction has been going on for a couple of millennia. The production of silicate brick can be divided into 3 main stages: preparation of raw materials, lime slaking and the actual production of blocks. Preparation includes the following stages and devices:
Seeder for sand. The fraction of sandy raw materials should be no more than 2.5 mm, moreover, the sifting process allows you to clean the sand from organic inclusions.
Installations for crushing quicklime.
Installation of pre-slaking lime is possible.
The device dosing feed of raw materials to mix.A mixture of 90-92% consists of sand, the rest is slaked lime, color pigments and modifiers.
Installations for slaking lime are divided into 2 types:
Drum installations using water vapor allow you to quickly complete the quenching process in the mixture, but are energy-consuming.
Silage structures of several sections allow to obtain a continuous stream of the finished mixture, despite the fact that the reaction may take up to 10 hours.
At the last stage, the blocks are formed in pressing machines and the raw material is sent to an autoclave, where calcium hydrosilicate compounds are formed under pressure and high-temperature steam in a brick, which provides hardness to the building block. Autoclave processing lasts 10-20 hours, so the installation of several autoclaves will be required for continuous production.
This machine for the production of bricks and other blocks based on building mixtures is a fairly universal means, because the replacement of forms can be made without significant modifications of the entire installation. There are models with metering devices, mixers and even transporters of products to the place of drying or additional processing.
Hyper pressed brick blocks
This production version does not use temperature treatment at all, as it is based on the cement binding property. The production line is minimized, which allows you to place it in a small area. The structure of the equipment, in addition to the hyperpress itself, may include the following installations:
Filtering and crushing equipment for grinding raw materials and removing organic debris.
The batcher for automatic control over giving of components.
Mixer, can be built into the design of hyper press.
Installation of transportation of bricks to the place of storage
Ready options mini-plants
Despite the abundance of manufacturers, the building materials market is not oversaturated, according to experts, they also note a stable annual growth in demand and construction volumes. Therefore, its own mini-factory for the production of bricks can become a profitable family business. The payback period of such a business can be from one to two years, depending on the established production and skills of the workers, as well as the ways of marketing the finished material.The minimum investment in process equipment and commissioning can range from 3 million rubles. up to 1 billion. To this should be added the rent of suitable premises and the purchase of raw materials. Especially it is worth paying attention to the production of hyperpressed brick, which requires the least amount of space to accommodate installations.
Production in the garage
To open the production of bricks in the local area, it will be enough to spend money on hyperpress, then all other operations will have to be done manually. The cost price of such a brick will be the most minimal, but the labor costs are much higher.
The profitability of the brick business is confirmed by many examples.