Design of clay gravel plant with density of 250-300 kg/m3

Contents

Contents

Introduction

Regulatory References

Special terminology

Reductions

1. Technological part

Justification of the need to release expanded clay gravel

Selection and substantiation of the method of production of expanded clay gravel

Ceramic gravel nomenclature on this process line

Selection of equipment for the production of expanded clay gravel

Development of clay gravel production line diagram

Description of clay gravel production technology on the developed process line

Development of the plot plan of the enterprise

2. Design part

Calculation of clay gravel production on the process line

 Calculation of line operation mode

Calculate Requirements for Source Components

List of main process equipment

Calculation of the quantity of the main process equipment

Calculation of storage capacity of finished products. 

Technical and economic indicators of the general plan

3. Technical and economic part

. Personnel list for shop floor or process line

. Calculation of the cost of production of expanded clay gravel

4. Control at all production limits

5. Documents developed at the enterprise, which are regulatory for the production of expanded clay gravel

6. Safety and Environmental Friendliness

Conclusion

List of sources used

Project Description

Graduation qualification work: 64 p., 6 Fig., 14 Table, 11 sources.

The illustrative part of the thesis contains: 5 sheets of A1 format.

CERAMSITE, CERAMSITE GRAVEL, GAS FORMATION, POROUS FILLERS, ROASTING, PLASTIC MOULDING

The purpose of this diploma project is to design an enterprise for the production of ceramzite graphics with a density of 250300 kg/m3

The substantiation of the need to design the plant, the nomenclature of the manufactured products is given. Product production schemes have been developed. Process description is given. Equipment is selected and calculation of energy resources is given. Control of technological processes and qualities of finished products is described, technical and economic indicators and a standard list of the workshop are given, health and safety issues are considered.

Introduction

Materials of the ceramic structure are a new group of heat-insulating ceramic construction products. In the production of all products by classical methods of ceramic technology, they tend to achieve a certain degree of sintering of the ceramic tile in firing, and ceramzite-type materials are obtained by swelling during firing of the clay mixture. Swelling is an increase in the volume of the material due to the formation of an internal, mainly closed porosity.. In fracture, expanded material has structure of frozen foam. Thus, we will call ceramic materials those that are obtained by swelling clay rocks when they are fired.

Ceramzite type materials are ceramzite gravel, ceramzite sand and unit ceramzite. Unit ceramsite is known as cellular ceramics and foam ceralite. The most developed was the production of expanded clay gravel, which is usually called expanded clay. Clay gravel with a low density of 250300 kg/m3 has a great demand in the construction materials market. The production of such expanded clay with good thermal insulation qualities is very relevant for our time.

Regulatory documents

GOST 975790 "Gravel, gravel and sand artificial porous. Specifications. "

GOST 12.200391 Occupational Safety Standards System. Production equipment. General safety requirements. "

GOST 975889 "Porous inorganic fillers for construction works. Test methods "

SP 56.13330.2011 Production buildings. Updated version of SNiP 31-03-2001

SanPin 2.2.3.138503 "Hygienic requirements for enterprises producing building materials and structures."

SNiP 2.04.1488 "Thermal insulation of equipment."

Special terminology

Grove is a loose large-fragmented (psephite) sedimentary rock composed of rolled rock fragments (sometimes contains fragments of minerals measuring 110 mm) formed as a result of the natural destruction (weathering) of solid rocks.

Expandability - The intumescence of clays is estimated by the coefficient and density of the expanded granule, which can be obtained from this clay.

The value of the swelling coefficient depends on the porosity of the rock, the size of its particles, homogeneity and chemical composition.

Shungit is a Precambrian rock that occupies an intermediate position between graphite and anthracites in composition and properties. There are varieties of shugnite, dark-skinned, black and brown.

Water absorption - the ability of a material or product to absorb, as well as retain water in pores and capillaries. Weight water absorption is numerically expressed as the ratio of the weight of water absorbed by the sample at full saturation to the weight of the dry sample.

Clay plasticity is the ability to change and maintain shape when sculpted without cracking. It is directly dependent on the physical structure of the clay particles, which is determined by the structure of the rock that formed the clay, and the time when the clay particles are transferred by water.

Abbreviations and abbreviations

GOST - State Standard.

SNiP - Building Codes and Regulations.

SanPin - Sanitary - epidemiological standards and rules.

SP - Code of Rules

QoC - Technical Control Department

Plot Plan - Master Plan

PPE - Personal protective equipment.

PISOD - Personal Respiratory Protection

Selection and substantiation of the method of production of expanded clay gravel

Depending on the methods of clay treatment and granule preparation, three methods are distinguished: a) dry, b) plastic, c) slip. Method of granules dry production.

In this method, clay granules are not formed, but are formed by crushing and sowing quarry clay. It can and should be used when working with stone-like brittle clay rocks (clay shales, argillites), which are difficult to wash in water. When crushing, such clays should give a volumetric crumb with a relatively small yield of fines - up to 15%. If the clays have a pronounced solidity and when crushed give a large amount of "bream" - thin plates, then they are not suitable for the production of expanded clay, since the bream practically does not swell. In addition, in this method of preparing granules, the rock should not contain limestone inclusions, since in this method it is not possible to remove them from clay. Granules are dried at quarry moisture content of clay of more than 8%, in connection with which the drying drum is placed with the possibility of its bypassing .

When screening crushed clay, it is necessary to disperse it according to fractions in order to subsequently burn each fraction in a separate furnace, because the firing mode should be differentiated depending on the size of the fraction. A fraction with a grain size of more than 20 mm is returned to the crusher for repeated crushing, and a fraction of less than 5 mm is burned separately to obtain expanded clay sand. The co-firing of the coarse fine fraction may result in welding of the calcined pellets into a conglomerate .

The arrangement of the equipment is greatly simplified when used for crushing and sorting pellets of the SM739/740 grading plant.

The dry method is most economical in terms of investment and operating costs. However, the possibility of its use is limited, since deposits of stone-like high-emission clays are relatively rare in our country, and it is impossible to increase the intumescence of clays by adding additives in this method.

In the United States, shale clay deposits are widespread, and therefore the dry method has gained preferential use there. In recent years, according to the technology of the dry method of producing expanded clay in the USSR, the production of shungisite has been mastered, the raw materials for which are shungite shales mined in the Karelian Autonomous Soviet Socialist Republic .

Method of plastic molding of granules.

In this method, raw granules are formed from plastic clay mass. It is useful for loose and dense clays that wash in water when their quarry humidity is equal to or lower than normal moulding humidity. The content of stony inclusions in clay should not exceed 10%, and limestone inclusions should be not more than 1 mm in size.

It is preferable to have a covered mechanized clay reserve, which provides stable moisture of clay entering production, eliminates equipment interruptions due to transport difficulties and weather conditions and makes it possible to operate the quarry in one shift with three-shift operation of the rest of the equipment. In its absence, the open clay warehouse still provides better operating conditions for the equipment than when working with the direct supply of quarry clay to the production.

The presence of two clay beads is quite rare, although the double processing of clay in clay mixers significantly improves the quality of expanded clay .

In many operating plants, one hole rolls are installed, which are both processing and forming. However, practice has shown that in this case granules are obtained with a cut surface and, as a result, heavier and lower strength. The productivity of the hole rolls depends on the diameter of the pellets to be formed and varies from 8m3/h at d = 7mm to 25m3/h at d = 18mm .

The first ceramzite enterprises in our country used tape presses as a forming machine, not hole rollers. Some of them work until now. To avoid clogging the press grid, they decided to replace it with a tape press with hole rollers. In addition, hole rollers are a more compact and lightweight machine. They can be mounted on floor floors and on floor floors, while tape presses require a massive foundation. However, at present, a significant drawback of hole rollers as a forming machine has also been revealed - the length of the granules is formed spontaneously in them and it cannot be adjusted. As a rule, they give granules with a large value of the shape coefficient that reduces the strength of expanded clay. Tape depressants have a certain advantage in this regard - on them you can obtain granules of a given length and thereby adjust the shape coefficient of expanded clay. However, due to the fact that the size of the shape coefficient was not regulated in GOST 975961, most ceramsite enterprises continue to work with the formation of granules on hole rollers. In addition, tape presses provide a more intensive study of clay, as a result of which light expanded clay is obtained. Some factories replaced the hole rolls with belt presses, while improving the quality of the expanded clay produced.

When assigning the diameter of the molded granules, it should be borne in mind that the curve of dependence of the volume mass of the expanded granule on its diameter in the raw material is extreme and, therefore, each clay corresponds to a certain diameter of the crude granules, giving expanded clay with a minimum density .

Beads are not always dried prior to firing. In some cases, there is increased intumescence of the pellets when they enter the furnace directly from the molding machine without prior drying. However, such a scheme is only applicable with high crack resistance of the clays in drying and high intumescency thereof. In the latter case, if the pellets in the furnace even break down, then their fragments will still swell, giving light expanded clay. Fragments of granules from medium and weakly entangling clays in firing hardly swell and noticeably weigh the expanded clay. Work without preliminary drying of pellets is also inconvenient because in this case the molding compartment should work in three shifts, and interruptions in the operation of the molding equipment immediately cause disruptions in the operation of the furnace. But even in the absence of visible interruptions in the operation of the clay processing equipment, fluctuations in the supply of the furnace with the semi-finished product in the absence of a buffer stock of dry granules are quite large due to the uneven operation of the box feeder. Fluctuations in its productivity according to studies of the Research Institute of Ceramsite are (in%): daily ± 19, hourly ± 70, minute ± 100 with ± 7.5 permissible for normal operation of the furnace. Therefore, the presence of a drying drum and a buffer reserve of granules is the most important prerequisite for normal operation of the furnace .

The moisture content of granules leaving the drying drum is 12-14%. Storage silos of dried pellets reliably work only if there is supply and supply ventilation to evacuate water vapors emitted from hot pellets. In the absence of such ventilation, the pellet hangs in the hoppers.

Emptying raw granules with refractory clay or kaolin makes it possible to burn granules at a higher temperature and thereby reduce the density of expanded clay and increase the volumetric productivity of the furnace. The approximate flow rate of the dusting powder is 3-5% by weight of the crude granules.

The dusting powder can be prepared according to the scheme: The thonin of the dusting powder must correspond to the full passage through a screen with holes measuring 0.315mm. Emptying is carried out in a drum installed after the forming machine .

The plastic method is more complex and expensive than dry, but it allows the use of clays of more common varieties and makes it possible to introduce additives into clay that increase its intumescence. As a result, it has gained priority distribution in our country.

Slip method of granules preparation.

It is mouldless. Clay slip is fed into the rotary furnace, and granules are formed spontaneously in the furnace itself. This method is useful when the quarry moisture of the clays is higher than molded, as well as for clays whose natural structure is difficult to destroy by plastic processing, with high viscosity clays and with a significant content of stony inclusions in the clay (more than 10%). For the primary crushing of clay, disintegrator rolls, roll-toothed crushers and disc clay cutters of the Obukhovsky DSK structure can be used.

Clay slip is prepared in loot-type clays. Their diameter reaches 12 m, and productivity - 60 t by dry weight. Their advantage is the accident-free work with clays clogged with rocky inclusions, including large flint ones. Large stony inclusions are delayed by the exhaust grate of the clay thimble, remain in it and are periodically removed. Small inclusions with a size of 0, 5-10 mm must be separated on an arc sieve, to which the slip is supplied under a pressure of 0.2-0.3 mPa. Prepared slip should have flowability of 10 sec and spreadability of 65 -75mm; it is determined on the MKhTI-2 device.

To reduce moisture content of slip, electrolytes are introduced into slip. The stock of slip is stored in special tanks - sludge pools. They are vertical with a diameter of 8m, a capacity of 1000m3 with pneumatic mixing, as well as horizontal round with a diameter of 35m, a capacity of 6000m3 with crane stirrers and pneumatic mixing .

The slip method has serious advantages: it is the most versatile and allows the use of clays with a wider range of properties. The solution of the problem of cleaning clay from rocky and carbonate inclusions is significantly simplified in this method. Clay can be thawed in clays. Therefore, there is no need to insulate the supply of clay for work in winter. Ceramsite is lighter and smaller than in the plastic method.

The disadvantages of this method include increased fuel consumption and a decrease in furnace productivity of about 25-30% due to the need to evaporate a large amount of moisture.

The intermediate between the plastic and slip production method is a moulding method, in which a viscous-flowing molded clay mass with an approximate moisture content of 30-35%, pre-treated on runners or smooth rollers, is not supplied to the furnace. Such a mass is granulated in the drying zone of the furnace under the influence of chain curtains. This method has become widespread in Western Europe.

In the production of expanded clay, two types of roasting furnaces are used: 1) single-drum, 2) two drum.

At the beginning, single-drum furnaces were indicated in the projects. Then, as knowledge of the essence of the processes occurring in clay in the process of temperature treatment of it in furnaces accumulated, especially when it was accurately established that after heating the clay granules to the transition of the surface of the granules, the temperature should be sharply raised, then two drum furnaces were designed. Most plants producing expanded clay have single-drum furnaces.

After analyzing the three methods of preparation of raw clay granules for our project, we choose a plastic method of forming granules. Taking this method of forming pellets, you need to make a choice of several options.

1). There are factories where clay brought from the quarry is immediately supplied to the production of granules. There is an opinion that clay must be first processed, then put in an clay reserve homogenizer where the thinnest plates of the clay structure are impregnated with water, swollen, that is, the homogenization process will take place and after that raw granules will be prepared from such clay. Accept the option - in the process line, provide an clay storage tank with a capacity of 14 days of operation of the process line.

2). Formation of raw granules. There is a method of forming pellets in a rotary drum. As the clay rotates and moves, granules are formed and fed into the kiln. There is a method of forming granules with hole rollers. There are results of research conducted at the Kazan University of Technology, which substantiated that raw granules must be compressed. We will accept for our project a method of pressing granules using a belt press, which is used in the production of bricks, only without vacuumizing clay. We need air inside the clay.

3) There are always stone-like inclusions in quarry clay. To separate them from clay, stone-separating rollers are used in some factories. Practice shows that one hundred of them work inefficiently. Today, wet milling runners are used at ceramzite gravel plants. They grind all the stones in the clay.

4) There are factories with single-drum roasting furnaces. When more carefully theoretically considered the production of expanded clay was designed and began to use two drum kilns.

So we decide that in the process line we provide:

1. Wet milling runners, 2) clay storage with capacity for line operation for 28 days, 3) method of plastic forming of granules using belt press.

4) two-drum kiln.

What documents should be developed in the enterprise that are regulatory for the production of these products. Process Regulations

Technological Regulation (TR) is a regulatory document of the enterprise for internal use, which establishes production methods, technical facilities, technological standards, conditions and a detailed procedure for the implementation of the technological process.

This document allows you to obtain finished products of quality that meet the requirements of Russian or international standards. The Technological Regulation also introduces the safest methods of conducting work, which at the same time contribute to achieving optimal technical and economic indicators of production.

The Process Regulations prescribe all production processes with a high degree of detail.

There is an AETD - Unified system of technological documentation, which is part of the AETPP - Unified system of technological preparation of production.

In accordance with the provisions defined in these systems, the development of technical documentation of the enterprise is provided by the organization itself. Specialists or third-party organizations may be involved in the creation of technical documentation. In cases established by law, technical documentation is registered with supervisory organizations.

Technical documentation is required to describe in detail the processes, methods and methods of manufacturing the product, the characteristics of production, and its control. Technical documentation may be required in the following cases:

When issuing certificates of conformity;

in the execution of contracts;

during inspection by supervisory bodies.

Technical documentation can be divided into three large groups. This is a technical document:

For technological processes;

for products;

quality management system.

The main process document of the AETD is the roadmap.

Process procedures are described in the Process Regulations. In addition to them, there are also enterprise standards, process maps, process and work instructions for processes, methods and other technical documentation. The Process Regulations are the main working document for engineering personnel and workers involved in the production process at the enterprise.

Process regulations can be of three types:

permanent ones intended for production according to the developed technological process;

temporary - for new developed products, when using new equipment or if major changes are made to the technology;

one-time - for research work or for the release of a one-time batch.

Industry-wide documents that are normative in the development of Technological Regulations are: Federal Law "On Industrial Safety of Hazardous Production Facilities" of July 21, 1997 and Decree of the State Gortekhnadzor of Russia No. 77 of December 18, 1998 - Regulations for the development of TR "Safe Operation of Production Facilities."

It is recommended to develop TR for the production of a specific product (product, semi-product) or groups of products that are of the same type according to the technological process.

The technological regulations contain the following sections:

General characteristics of production;

description of characteristics of materials, raw materials, reagents, semi-products;

description of the process and production flow chart;

norms of technology regimes;

description of process control;

description of start-up and production shutdown;

description of safe operation of production;

Description of wastes, wastewater, emissions to the atmosphere, indicating methods of their processing, disposal;

brief description of process and pump-compressor, control and safety equipment;

list of regulatory documents and mandatory instructions;

graphical Production Flow Chart.

The period of validity of the Technological Regulations is determined by law, but, as a rule, is 5 years. After which, if there are no significant changes in production, it is extended for another 5 years. If the company is going to launch the production of new products or put into operation new equipment, then TR is being developed for 2 years.

Conclusion

In this diploma project, a technological scheme for the production of expanded clay gravel was developed and proposed. This technology corresponds to the rational and optimal use of resources and raw materials, technological and thermal equipment and the modern level of industry development.

The criteria for selecting equipment were power consumption, energy consumption, equipment maintenance and operation costs, and productivity for the execution of the production program.

This process scheme is designed to ensure a reduction in the production cycle, a reduction in scrap, an increase in physical and mechanical indicators, the competitiveness of expanded clay, and, therefore, low cost, large production volumes and quality.

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