Production of gas silicate plates

Contents

INTRODUCTION

1 Process Part

1.1. Nomenclature of products produced

1.2 Raw Materials

1.3 Production Flow Chart

1.4 Operating mode of the designed enterprise

1.5 Design Enterprise Performance Calculation

1.6 Calculation of requirements for raw materials and semi-finished products

1.7 Selection of main process and transport equipment

1.8 Process and quality control of finished products

2 Occupational safety and safety at the enterprise

3 Environmental Engineering Measures

CONCLUSION

List of sources used

Appendix A. Patent № 2018438 of the Russian Federation

Appendix B. Patent No. 2264777 of the Russian Federation

Task

for coursework in the discipline:

"Technology of heat insulation and acoustic materials"

1Thema: "Plant for the production of heat insulation plates from gas silicate

2 Initial data for course work:

2.1 Plant capacity - 65 thousand m3 per year

2.1 Raw materials: calcium lime, quartz sand, gasifier.

3 Content of coursework

3.1 According to the guidelines for performance and execution of the course work

4 List of graphic materials:

4.1Sheet of A1 format showing the process diagram of production of heat insulation plates from gas silicate

5 Due date for protection: December 2014

Introduction

The development of high-comfort housing, which meets modern heat engineering standards for the design of enclosing structures, involves the creation of more efficient compared to traditional building materials and new structures with improved heat engineering properties.

One of the most promising areas of solving these problems is the production of wall materials using cellular concrete. The use of cellular concrete as wall and heat insulation materials allows, compared to traditional products, to increase the thermal resistance of enclosing structures from 1.5 to 2 times and reduce the heat consumption for heating buildings from 20 to 40%.

In the current energy crisis, high heat-shielding properties for construction material are of paramount importance, since the costs of maintaining buildings at an ever-increasing cost of energy are increasingly determined by the costs of heating and air conditioning. Cellular concrete, having high heat-protecting properties and heat-accumulating capacity, prevents significant heat loss in winter and avoids too high temperatures in the room in summer, eliminates a sharp fluctuation in temperature in the rooms, which causes a favorable microclimate, both for normal life activities of people and for the operation of devices and installations sensitive to changes in temperature and relative humidity of air.

The developed advanced technology and modern equipment make it possible to produce gas concrete with a density of 300 to 1200 kg/m3, hardening at atmospheric pressure with high physical, mechanical and thermal performance.

For a number of important indicators, such as low density, high heat insulation capacity, etc., cellular concrete products are superior to traditional building materials. They have significant advantages over brick and other wall materials. The walls of their houses are three times lighter compared to brick walls and therefore cheaper and warmer. Labor costs in the production of this material and in the laying of residential buildings from it, respectively, are two to three times less than in the construction of brick buildings.

The development of the construction industry in recent years in our country has entailed an increase in the number of gas silicate manufacturing plants. The Government's affordable housing programme has also played an important role. In the city, as well as in rural areas, the number of low-rise objects has increased.

The purpose of the course work is to design a technological scheme for the production of gas silicate plates taking into account modern quality management requirements.

Process Part

1.3 Production Flow Chart

Due to the wide variety of technological schemes for the production of building materials and products, it is necessary to determine possible methods of production, variants of production lines.

Gas silicate plates are manufactured using casting and vibration technologies. In accordance with this, production process diagrams are assembled.

According to the casting technology of production, the gas silicate mixture is poured into metal molds with given cell sizes. The shape for gas silicate consists of a pallet, four folding sides, locks and dividing partitions. Gas silicate is poured into molds without vibration with subsequent leveling of the surface with a metal ruler.

The main disadvantages of casting technology are:

- labour and metal capacity;

- low performance;

- plate divergence in geometric dimensions ± 5 mm (especially at height) and difference in surface quality;

- Other metal molds are required for the production of gas silicate plates with different dimensions.

Therefore, many domestic firms use vibration manufacturing technology, which provides a higher level of mechanization and productivity.

Vibration manufacturing technology provides for pouring of gas silicate mixture into molds without cells with easy-to-remove formwork. After filling the moulds with a gas silicate mass and achieving the required plastic strength, the mass is fed to a cutting machine, where a special string is cut in three planes into products of a given size. The design of the gas silicate cutting complex ensures the manufacture of plates with an accuracy of ± 5 mm and surface quality that meets the requirements of standards.

When cutting gas silicate plates compared to casting technology:

- improved quality of manufactured slabs;

- the number of labor-intensive operations is reduced;

- the number of workers is reduced;

- the cost of the slabs is reduced;

Taking into account all the characteristics, the designed enterprise has adopted an aggregate-flow production method according to the vibration technology of producing gas silicate plates [7].

The process of producing gas silicate plates includes the following operations:

a) storage, preparation and supply of raw materials;

b) joint grinding of lime and sand;

c) preparation of suspension;

d) preparation and dosing of concrete mixture;

e) forming the massif in shapes - massifs;

f) forming and preparation of molds (cleaning, lubrication, assembly);

g) cutting the massif into products of a given size;

h) autoclave processing of articles on pallets;

and) removing the plates from the pallets;

k) marking and packing of finished products.

Quartz sand by rail enters the sand warehouse. The conveyor then enters the mixer feed bin.

The quicklime powder comes in cars where it is in containers. Lime is discharged from containers into silos.

The gasifier is delivered by road in tanks and stored in a warehouse.

Lime and sand from the service hoppers are fed alternately to the ball mill, where the raw materials are ground to a specific surface area of 300 to 400 m2/kg.

After grinding, the raw material enters the dry components weighing dispenser, water is supplied through the liquid weighing dispenser. The weighing dispensers installed on the line are combined with a control system providing the set of the required number of raw components and unloading the dispensers to the mixer according to the specified program.

The components loaded into the mixer are mixed until a homogeneous solution is obtained, after which an aluminum slurry is supplied to the mixer. The technology uses a 1.4 m3 mixer, which provides filling of the mold with a volume of up to 1.1 m3. The finished mixture is discharged into a metal mould through the lower neck of the mixer.

The mold consists of a tray on four wheels moved along rails and a removable cap. The pallet is a trolley on four steel wheels with a wooden base protruding above the metal frame. The removable cap consists of two parts "g" - shaped and in assembled form forms four faces forming a massif. Before filling the gas silicate mixture, the removable formwork is collected, lubricated with a special solution or laid with oiled paper and placed on a tray. Caps are fixed on pallets by wedge locks. Rubber seals are provided along the contour of cap contact with the tray.

Prepared mold is installed on vibration platform rails. The time of cyclic action of the vibration platform during filling and swelling of the mixture is from 3 to 10 minutes, depending on the type of binder.

After filling with the gas silicate mixture, the mould is delivered by means of the mould pusher to the point of decay strength. Mold displacement pusher is located under molds between rails and consists of rod with stops moved along rollers. The movement drive is electromechanical. The pusher moves the mold through the pouring position, the holding area and the cutting machine, pushing the tray onto the transfer trolley.

In order to ensure high strength characteristics of the material, it is very important to provide a rigid temperature regime at the time of strength gain. The retention time of the massif in shapes before cutting is from 1.5 to 2 hours.

After the decompression strength has been gained, the sides are removed from the tray and the gripper mounted on the telfere is transferred to the formwork return trolley, which moves along the rails parallel to the forming line .

The formwork is cleaned, collected, lubricated, installed on a free tray and supplied to the pouring.

The tray with the massif after removal of the formwork is pushed onto the cutting complex. At the cutting position, the tray-car is clamped and a frame with longitudinal and transverse cutting mechanisms installed on it is lowered onto the array. Massif is cut by oscillating strings simultaneously in transverse and longitudinal directions. String oscillation frequency 80 double strokes per min. String oscillation amplitude 14 mm. Lowering and lifting of frame with strings is performed by electromechanical drive. Drives of the product cutting complex are powered by a frequency converter, which provides control of the rate of oscillation of the strings of transverse and longitudinal cutting, accurate stopping of the lifting frame in the final positions, allows reducing the rate of lowering and lifting of the frame at the moment of the strings entering and leaving the array .

After the massif is trimmed from the sides, waste remains that is collected on the tray and collided by the pusher onto the belt conveyor. Waste from cutting by conveyor is fed into mixer of waste processing. Mixer for collection and processing of wastes consists of housing with mixing device. The cuttings from the massif are mixed with water to obtain a uniform mass, which is pumped by a centrifugal pump to the sludge basin. The collected sludge is dosed and supplied to a gas silicate blender.

After cutting, the tray is unlocked and pushed onto the power transmission bridge. The bridge operates automatically and transfers the array tray to the autoclave chamber.

The transfer bridge consists of a platform with rails on which a tray with a massif is located, while the platform moves in the transverse direction by an electric drive. Drive consists of electric motor, brake, reduction gear and chain transmission. The engine control system slows down the speed of the trolley when approaching the rails.

Pushers are installed in front of autoclave for pushing trays with arrays. The pusher of the cars ensures that the composition of the cars is dragged through the autoclave chamber. Rod travel 2.5 m. Motor drive through reduction gear and chain gear. The chambers are closed on both sides by lifting doors, which ensures maintenance of the required mode of thermal moisture treatment due to heat from cement hydration, without additional energy supply.

The heat treatment process takes from 70 to 80% of the time of the entire production cycle of gas silicate plates. Heat treatment of obtained articles takes place in autoclaves at temperature of saturated water vapour from 174 to 191 ° C for 1214 hours, pressure from 0.9 to 1.3 MPa. Heat treatment of heat insulation products is performed until they achieve the required tempering strength.

Thermophysical properties of concrete during thermal moisture treatment vary depending on temperature, pressure and humidity of the environment and accordingly the process of thermal moisture treatment in the autoclave can be conditionally divided into the following stages:

The 1st stage proceeds at a pressure in the autoclave of 0.1 MPa and a temperature not higher than 100 ° C with intense condensation of steam due to its cooling when in contact with cold surfaces of the articles, which contributes to the rapid heating of the latter.

The 2nd stage is characterized by intensification of heat exchange caused by an increase in pressure and temperature of the medium in the autoclave. Condensation of saturated steam continues. Heat exchange is also facilitated by increasing the temperature difference between the surface and internal layers of concrete and the thermal conductivity of concrete due to physical-chemical and structural transformations occurring in it.

Stage 3 is characterized in that when a maximum pressure of 0.8, 1.0 or 1.2 MPa is reached depending on the selected treatment mode and, accordingly, the temperature of 174.5; 183; 190.7 ° С is the period of isothermal holding. Internal heat exchange continues, spreading from the surface deep into the product.

The 4th stage proceeds with a decrease in pressure to atmospheric and, accordingly, temperature, which is accompanied by rapid evaporation of moisture accumulated in concrete and cooling of concrete. During this period, a large pressure drop across the cross section of large-sized articles made of heavy silicate concrete can lead to cracks. In cellular concretes, due to the rapid equalization of pressure, a large difference is not observed.

The 5th stage is characterized by the fact that in order to reduce the retention period of articles in the autoclave at atmospheric pressure, it is recommended to vacuum the autoclave to reduce the temperature difference in the weight of concrete. Vacuumization also facilitates rapid evaporation of moisture from concrete pores.

After opening the autoclave cover, the cooling of the surface of the articles to the shop temperature occurs slowly even further due to the continued evaporation of moisture from the surface of the articles and the presence of their higher temperature in the center [8].

After autoclave treatment, the array is cooled to a surface temperature of 40 to 65 ° C and a polymer mineral coating of the following composition is applied by means of a nozzle, wt%:

butadiene-styrene latex 11 to 18;

- bone glue from 0.055 to 0.065;

- mineral filler of fraction not more than 2.5 mm from 41.8 to 80.0;

- water.

Finishing composition of mineral coating polymer type is applied on open faces until massif is divided onto plates, then at least one horizontal or vertical row of plates with finishing composition is separated from massif and finishing composition is applied onto released faces of the next row of plates in massif.

Gas silicate plates, the surface of which is treated by the proposed method, acquire the following physical and mechanical qualities of the protective coating:

- coating adhesion to gas silicate from 2.2 to 2.3 MPa ;

- water permeability, not less than 500 h;

- weather resistance not less than 81 cycles ;

- frost resistance is not less than 100 cycles [9].

Having passed a stage of heatmoist processing, finished products have to be maintained within 2 hours indoors with a temperature not less than 18 wasps .

Then, by gripping the article, they are mounted on a transport tray and bound with a packing belt using a hand-held packing machine. Then the products are sent to the finished product warehouse. The boards removed from the arrays return to the beginning of the line, are lubricated, gripped on the telphere are installed on pallets, which, after removing products from them, return to the molding line

1.8 Organization of production control

Quality management of manufactured products shall comply with the requirements of GOST R ISO 9001 [15]. In accordance with these requirements, the organization must develop, document, implement and maintain a quality management system, constantly improve its performance in accordance with the requirements of the state standard.

The Organization shall determine the processes required for the quality management system and their application throughout the organization; Define the sequence and interaction of these processes Identify the criteria and methods necessary to ensure performance, both in the implementation and in the management of these processes; Ensure that resources and information are available to support and monitor these processes; Monitor, measure and analyse these processes; Take the measures necessary to achieve the planned results and continuously improve those processes. The Organization shall manage these processes in accordance with the requirements of GOST R ISO 9004 [16].

In order to determine the necessary controls, a documented procedure should be developed, which includes: checking documents for adequacy before their release; Review and update as necessary and re-approve documents; ensuring identification of changes and status of revision of documents; Ensuring that relevant versions of documents are available at their locations of application; keeping documents clear and easily identifiable; Preventing the unintentional use of obsolete documents and applying appropriate identification of such documents left for any purpose.

Senior management should analyze the organization's quality management system through scheduled intervals in order to ensure its constant suitability, adequacy and effectiveness. The analysis should include an assessment of improvement opportunities and the need for changes in the organization's quality management system, including quality policies and goals.

The Organization shall identify and provide the resources required for: implementation and maintenance of the quality management system, as well as continuous improvement of its performance; Increase customer satisfaction by meeting their requirements.

The organization must create and manage the production environment needed to meet product requirements.

The organization must maintain product compliance during internal processing and during delivery to the destination. This shall include identification, handling, packaging, storage and protection. The Organization must resolve the issue of non-conforming products in one or more of the following ways: take actions to eliminate the detected non-conformance; Authorize its use, issue or acceptance if authorised to deviate from the relevant authority and consumer, where applicable; Act to prevent its original intended use or use.

When a non-conforming product has been fixed, it must be re-verified to verify compliance. If non-conforming products are identified after delivery or use, the organization shall take actions adequate to the consequences of the non-conformance.

Environmental Engineering Measures

Protection of the environment in modern conditions of production development is one of the most important tasks. It provides for the implementation of measures aimed at preventing environmental degradation from the work of the designed enterprise, in accordance with the requirements of GOST R ISO 14031 [18] and GOST R ISO 14001 [19]. These standards establish requirements for the environmental management system to assist the organization in defining its policies and targets, taking into account the requirements of laws and data on significant environmental impacts. Management should define the organization's environmental policies and ensure that these policies are consistent with the nature, scope and environmental impacts of the organization's activities, products or services, include an obligation to continuously improve the environment and prevent pollution, and comply with appropriate environmental legislation.

Environmental protection is addressed through measures to protect against air pollution, natural waters, soils and natural resources.

In the process of producing autoclave gas silicate, exclusively natural components such as quartz sand, lime, water are involved. Fine dispersion aluminium powder is used for blowing.

Gas silicate boards do not contain chemical additives and other harmful impurities, which makes it possible to classify the material as environmentally friendly products. At the same time, the performance is so high that it ensures the preservation of the material for many decades .

The process of producing cellular concrete does not require a lot of energy, since the material solidifies under the influence of steam at a temperature of only 180 ° C. Secondary application of spent steam and secondary processing ensure the return of energy and water in the production cycle. Production waste can be recycled, which is also a contribution to environmental protection. In addition, resources are saved in the production process, since five cubic meters of building material are obtained from one cubic meter of solid raw materials as a result of blowing. Production residues of materials are returned to the process cycle and processed into other products .

Production does not have wastewater. Construction debris from building materials does not emit gases or other substances polluting the environment

Conclusion

In this course work on the topic "Plant for the production of heat-insulating gas silicate plates," a brief overview of the state, development prospects, production technology and properties of gas silicate plates was made.

Course work consists of an explanatory note and a graphic part. The explanatory note includes 47 sheets, 14 tables and 27 information sources. The graphic part is represented by format A1, which shows the process diagram of the plant for the production of gas silicate plates.

The explanatory note contains the following main sections: introduction, technological part, health and safety at the designed enterprise, measures of environmental engineering protection, list of used sources of information and conclusion.

The process part presents the range of products, selected raw materials, selected main and auxiliary equipment. Justification of method of production of gas silicate plates is given. The operating mode of the designed enterprise and the production program are calculated. The quality management section provides quality control of raw materials, operational process and finished products in accordance with the requirements of regulatory and technical documentation.

The section on occupational safety and safety at the designed enterprise and environmental protection sets out the basic requirements for the working conditions at the enterprise with the adoption of organizational measures to improve them. Environmental engineering includes modern environmental protection and pollution control, as well as the development of environmental protection methods by the construction industry.