Dry Building Mix Plant Design

Contents

Content    of pages

Introduction. Feasibility study for the reconstruction of the industry enterprise      Characteristics of the designed enterprise                                Nomenclature of manufactured products                 1.1.2The characteristics of local conditions         1.1.3Soil          base     and transport              1.1.4The composition of the       plant                1.1.5The operating mode of the enterprise                                                                                                                                                                                                                                                                    

2. Manufacturing technology of building materials, products, structures       

2.1 Main production technology 2.1.1 Main provisions of workshop        technology 2.2 Demand of                   main           production                materials 2.3 Selection of composition 2.4 Calculation of demand for production      areas               2.5 Calculation     of quantity of    materials,        Compressed Air         and Electric Power               2.6    Factory                  Laboratory                        and Product          Quality Control 2.6.1   Factory Laboratory and Product     Quality Control 2.6.2                  Process      Control Map 2.6.3 Acceptance Rules 2.7 Storage Facilities and Cargo Turnover of the Enterprise 2.7.1 Storage Facilities   2.7.2 Calculation  of Cargo Flows              3.  Organization of production                                                                                                                                                                                                                                                                                                                                                                                                 

3.1 Substantiation of production method                                    

3.2 Development of the organizational and technological structure of the production           process

3.3 Calculation of process lines quantity and equipment selection

3.4 Calculation and statement of manpower                                                                        

3.5 Calculation of process mode norms                                                          

3.6 Organization of auxiliary services of the workshop

3.7 Calculation of production load and employment factor of main workers

3.8 Organization of auxiliary areas of the main enterprise

3.9 Technical and economic parameters of production process organization         

4.    Heat engineering part                                                                              

5.   Automation of production                                                                     

6.   Architectural and construction part                                                            

7.   Design and structural part.                                                                

8.  Economic part                                                                                   

8.1 Calculation of raw materials, materials and electricity costs    

8.2 Calculation of labor costs

8.3 Calculation of general production costs 

8.4 Determination of cost of production

8.5 Technical and economic indicators                        

9.   Health and Safety                                                      

10.  Environmental  protection 11         . Research                       Part                                                                                                   

          List of sources used                                                           

1 Introduction. Feasibility Study for Design or Refurbishment of an Industry Enterprise

1.1 Characteristics of the designed enterprise.

1.1.1 Nomenclature of manufactured products

Produced dry solution mixtures are designed for: 

- laying of bricks, concrete and cellular concrete blocks; 

- preparation of assembly mixtures ;

- performance of facing works, gluing of gypsum board and sealing of interplate seams for gypsum board; 

- finishing works with plaster solutions inside and outside buildings; 

- repair of walls ;

-screens for floor (self-driving filling floor) 

1.1.4 Plant composition

The designed dry building mix plant consists of main and auxiliary workshops. The main workshops include:

- Sand drying shop;

- Mixing workshop for production of dry building mixtures of selected nomenclature;

-The finished product warehouse is intended for storage of finished products before their export to the consumer. Storage is carried out at closed sites;

- Cement (silo type), lime (silo type), gypsum (silo type ) and fillers.

Auxiliary production includes:

-Mechanical repair shop designed for repair and maintenance of production equipment and vehicles of the enterprise;

Compressor room designed to supply compressed air for production needs;

Boiler room used for heating of premises in winter, as well as for steam production;

- Transport boxes representing auto, rail and intra-plant transport;

 Fuel and lubricant warehouse;

-Transformator;

-Fire pond.

Manufacturing technology of building materials, products, structures

2.1 Main Production Technology

2.1.1 Main provisions of workshop technology

The main stages in the production of dry building mixtures are:

acceptance, drying and transportation of sand

-Installation and loading of additives

-Receiving and loading binders

-process stock storage

- dispensing

- mixing

packing and loading works

- dust removal

-preparation and supply of compressed air

-management of production

Acceptance, drying and grading of sand.

The loader supplies sand from the factory site of temporary storage to the receiving bin. Two vibration feeders ensure uniform uninterrupted supply of sand to the receiving pocket of the bucket elevator, which transports sand to the drying drum. This drum is equipped with an automatic gas burner. It has seven speeds of rotation, which ensures maintenance of the specified temperature in the drum drying chamber and uniform drying of sand to the specified percent humidity regardless of weather conditions. Humidity of dried sand. The automatic hose self-cleaning flue gas filter is equipped with a counter-blowing system providing an air cleaning coefficient of 0.99. The temperature of the flue gases, the degree of contamination of the flue filters, the speed of rotation of the drying drum and the output of the vibration feeders are controlled by the factory processor and can be adjusted automatically or manually. The vibration feeder supplies dried sand to the receiving pocket of the bucket elevator.

The sand is fed by a bucket elevator to the highest point of the mixing tower, where the control screen is located. The control sieve is made in the form of a vibration rochot and is equipped with a productivity regulator that allows influencing the quality of sand sowing. The dispersed sand fractions are fed to the filler tanks. Sand fractions above 1.5 mm are discharged into containers and can be used in the production of special compositions.

Bucket elevator, control screen and filling tanks are equipped with local ventilation system. Exhaust fan with hose self-cleaning filter removes sand dust; The filter is equipped with a cell feeder supplying collected dust to the tank with sand fraction up to 0.25 mm.

Acceptance and loading of raw materials (additives).

The various additives used in the recipes are stored in the factory warehouse. Daily, in accordance with the daily production plan, additives are fed by means of a chain hoist to the service site of additive silos and filled into them.

Acceptance and loading of raw materials (binders).

Tanker trucks deliver cement, dolomite to the plant from a rail warehouse (raw material base). The supply of binders, fillers, additives by road is also carried out. Transport pipeline of binders is equipped with receiving branch pipes allowing connection to system of flexible hoses of tanker truck. Air pumped by a tank truck compressor or a factory pneumatic system, binders are pumped into silos.

Storage of process stock of raw materials.

Filler tanks serve for temporary storage of fractional sand. The tanks are equipped with continuous level gauges that allow the processor to control the volume of fractional sand reserve. The aeration system protects sand from caking and eliminates the possibility of formation of "dead zones" in containers.

Binder containers are used for temporary storage of grey gypsum, cement, lime and dolomite. They are equipped with continuous level gauges and aeration system. Exhaust filters-fans are installed on the tank covers.

Additive silos are filled with additives daily. Due to the properties of the additives, the silos are not intended for storage. They are mobile, it is possible to quickly replace empty bins with pre-filled ones. Additive silos are equipped with aeration system.

Dosing.

In accordance with the recipe introduced into the factory control computer, the processor, controlling automatic pneumatic valves, doses all components for the necessary replacement on the scale.

A manual dosage system is provided for additives used in small quantities.

From the filler and binder weights, additive weights, manual dosing weights by means of the automatic valve system, suspended components are supplied to the mixer.

The dosing system provides dosing with an accuracy of 0.5%.

Mixing.

The dosages fed to the mixer are mixed according to a predetermined program. The program of work of the mixer for each recipe includes mixing time, the possibility of using additional mixers installed in the side walls of the mixer. The mixed finished product from the mixer is fed into a buffer tank, from where it is supplied to bags of 30 kg by means of a packing machine.

Packing and loading works.

After filling the bag of finished products, it is discounted to the conveyor line and moved to the robot stacker, passing the control scales and the printer, which sets the date of manufacture of the products. During transportation, excess air is removed from the bags, they are cleaned from dust. Bags are laid in the slab-laying device according to the specified program on wooden pallets. Then pallets with bags are packed in heat-shrinking film and taken by forklift to warehouse or to place of loading in motor transport.

Dust removal.

The exhaust fan with automatic self-cleaning hose filter of the vacuum cleaner removes dust from additive silos, filler scales and binders, additive scales, mixer, buffer tank, container of packing and loading line. Packaging machines, paper bag cleaning systems. Dust collected by the filter of the vacuum cleaner is loaded into the container and taken to a landfill.

Preparation and supply of compressed air.

Compressed air is provided by screw compressors, air cooler, moisture oil separator, air receivers.

Production control.

The plant installs control and production computers, a central processor, and local logical systems. The dispatcher computer monitors compliance with selected recipes, order execution sequence, and sends commands to the production computer.

The central production computer controls the process of drying, transporting and sorting sand, dosing filler, binders and additives, mixing, supplying finished products to packing and loading lines, a ventilation and dust removal system, and provides control over technical and technological parameters of production. 

4.2.2 Material requirements of main production

The following components are used as binders for preparation of dry building mixtures:

-Portland cement PC 500D0 as per GOST 10178 - 85. The cement should show uniformity of volume change when the samples are tested by boiling in water, and if the MgO content in the clinker is more than 5% - in the autoclave. Cement setting should begin no earlier than 45 minutes, and the end - no later than 10 hours from the beginning of the closure. The grinding fineness of the cement should be such that when screening a sample of cement through a screen with mesh N 008 according to GOST 661386, at least 85% of the weight of the screened sample passes.

- Gypsum construction G-3 as per GOST 12579. For the production of binders, gypsum stone is used according to GOST 401382 or phosphogypsum according to the current regulatory and technical documentation .

Strength is model-balochek the sizes of 40х40х160 mm at the age of 2 h, not less: 

under compression: G-3 - 3 MPa.

in bending: G-3 - 1,8 MPa.

The volume expansion of the binder must be no more than 0.2%. Content of impurities insoluble in hydrochloric acid is not more than 1.0%. The content of metal impurities in 1 kg of gypsum should not be more than 8  mg.

 hydrate lime of grade 1, in accordance with the requirements of GOST 9179 and additional requirements: the content of active (CaO + MgO) should be at least 67%, without additives 50%. The active CO2 shall be not more than 3%, with additions of 2%;

The strength of samples, MPa after 28 days of hardening must be at least: 

a) at bending:

0.4 - for weakly hydraulic lime;

1.0 - for heavily hydraulic.

b) under compression:

1.7 - for weakly hydraulic lime;

5.0 - for heavily hydraulic.  

The degree of dispersion of powdered air and hydraulic lime should be such that when sieving a sample of lime through a sieve with nets No. 02 and No. 008 according to GOST 6613, at least 98.5 and 85% of the weight of the sieved sample, respectively, passes.

The following fillers are used as fillers:

quartz sand meeting the requirements of STB 1727, with content of quartz not less than 70%, mica - not more than 0.5%, clay impurities - not more than 5%.

- perlite expanded sand M75, which meets the requirements of GOST 10832. The bulk density of perlite expanded grade M75 sand is up to 75 kg/m3 inclusive. Thermal conductivity at temperature (25 ± 5) ° С is not more than 0.043 W/( m· °  С).

Total specific effective activity of natural radionuclides in expanded sand should be not more than 370 Bq/kg.

- dolomite flour DT1, which meets the requirements of GOST 14050. The total weight fraction of calcium and magnesium carbonates is at least 80%;

- Calcium formate as per GOST 45077. The complex anti-frost additive is introduced into the mixture in the form of an aqueous solution of working concentration. The working concentration of the used solution is chosen by the consumer based on the requirements of the technology, the conditions of use and convenience of use. It is not recommended to use the additive in dry form, since the efficiency of its use in this case does not exceed 30%. It is recommended to introduce the complex additive with anti-frost effect into the mixture composition simultaneously with the first portions of closure water. During production, the distribution of the additive should be evenly distributed in accordance with regulatory requirements . Dosing of the additive shall be carried out with an accuracy of ± 2% of its calculated amount.

4.2.6.1 Factory laboratory and product quality control

The objectives and objectives of the factory laboratory are to control the quality of the concrete mixture and its components; control of those indicators of finished products (strength, frost resistance and crack resistance, etc.), which are determined by various tests. The plant laboratory shall be in direct communication with the relevant plant and quarry services.

The main functions of the technical control department are:

 control of product accuracy and surface quality;

 control of physical and technical properties of concrete, conformity of reinforcement, strength, crack resistance, stiffness of articles, etc.

 control of the level of factory readiness and quality of finishing of the surface of products;

 control over ensuring the safety of finished products;

  Product labelling control.

To ensure the quality of products in production, there are three types of control: input, operational, finished products. 

Incoming control.

Input quality control means the control of the supplier's products that have come to the consumer and are intended for use in the manufacture, repair or operation of products. Its main objective is the exception of a possibility of penetration into production of raw materials, materials, semi-finished products, components, the tool with derogations from the parameters of quality provided by standard documentation.

Main tasks of incoming quality control units:

- carrying out incoming quality control of products coming to the enterprise, execution of documents based on the results of control; monitoring of process tests of products in workshops, laboratories, test stations and other units;

- control over compliance of warehouse employees with the rules of storage and delivery to production of incoming products; calling supplier representatives to participate in drawing up an act on defects detected at the entrance inspection; analysis of causes of defects in the supplied products; preparation of statistical information on defects, their characteristics for its use in the product quality management system at the supplying plant.

All incoming raw materials and materials must be monitored. Control is carried out by the laboratory engineer and the obtained results are recorded in the technical passport and on the basis of these data determine whether raw materials and materials are subject to all requirements.

Operational control.

The Quality Assurance Service posts checklists for each production process. These cards are often placed at the equipment, and can be maintained by the operators or technologists themselves. The control card allows you to establish changes in the processing process over time caused by tool wear, fatigue phenomena of the metal, weakening of the attachment of the treated material, etc.

The control method is carried out according to TNPA, calculations, instructions, as well as visually.

Control of finished products.

Final product control shall be performed by laboratory engineer and quality engineer. Several samples of finished products are taken from each batch and tested.

Then, all data are entered in the test log and based on this log, conclusions are made about the quality of the finished product.

4.2.6.3 Acceptance Rules

Solution mixtures shall be accepted by the manufacturer's technical control. The solution mixtures are taken in batches. The batch includes a solution mixture of one composition prepared on one material according to one process mode. 

The volume of the lot is set depending on the requirements of the consumer, but not more than the daily production of the enterprise. Each batch of solution mixture (at the end of delivery of the whole batch), issued to one address, must be accompanied by a quality document, which indicates: 

- name or trademark and address of the manufacturer; 

- batch number and document issue date; 

- symbol of the solution mixture; 

- class of materials used for preparation of solution mixture , by  specific effective activity of natural radionuclides and numerical value of Aeff; 

- grade of solution by compressive strength; 

- grade of solution mixture by mobility;  

- design application temperature, ° С (at air temperature below 0 ° С );

- warranty shelf life (for dry solution mixtures), months; 

- weight (for dry solution mixtures), kg; 

- for RSGP - volume, m3; for RSPI - the volume of RPGP, m3, obtained after the addition of water necessary for the preparation of the solution mixture of the required mobility, and, if necessary, other components; for IPS - volume, m3, set taking into account the solution mixture compaction during its transportation ;

- date of preparation (for dry solution mixtures).  

If necessary, additional data can be entered in the quality document. The quality document must be signed by the official of the manufacturer responsible for technical control. 

The part of the RSGP and RSPI batch released in one vehicle shall be accompanied by a document indicating: 

- name or trademark and address of the manufacturer; 

- document number and issue date; 

- date and time of preparation of the solution mixture; 

- symbol of the solution mixture; 

- for RSPI - approximate amount of water required to prepare the solution mixture of the required mobility, and, if necessary, other components, kg/m3; 

- type of added chemical additives according to STB 1112; 

- design application temperature, ° С (at air temperature below 0 ° С );

- mass of the solution mixture in the vehicle, kg (volume of RCGP, m3, which can be obtained after the addition of water necessary for the preparation of the solution mixture of the required mobility).      Acceptance of solution mixtures is carried out according to the results of acceptance and periodic tests. Each batch of solution mixture is subjected to acceptance tests.  

During acceptance tests,   the following is determined:

a) when controlling water-containing solution mixtures  :

- mobility;  

- spreadability; 

average density of the solution (for light solutions); 

- compression strength of the solution  ;

b) at control of dry solution mixtures: 

- bulk density; 

- humidity; 

- spreadability; 

average density of the solution (for light solutions); 

- compression strength of the solution (except for heat resistant  solutions).

 During acceptance tests  , the presence of markings    is determined and the integrity of the package is checked. 

Acceptance and delivery of batches of solution mixture is performed before completion of tests on compression strength and average density of solution .

 The manufacturer shall ensure that the required  compressive  strength and average  density of the solutions are achieved when tested at the design age.  

Periodic tests determine: 

- consistency (for solution mixtures with grain size not more than 0.63 mm); 

- viability of the solution mixture;  

- water retention capacity; 

- relaxability; 

-   shrinkage;

- shrinkage deformations; 

- tensile strength in bending; 

- average density of solution (for heavy solutions); 

- strength of adhesion to the base; 

- strength of adhesive joint at uniform separation; 

- frost resistance; 

- specific effective activity of natural radionuclides;  

- design temperature of solution mixture application; 

- steam permeability coefficient; 

- thermal conductivity coefficient; 

- waterproof;  

- self-stress or linear expansion;  

Periodic tests shall be carried out within the period agreed with the consumer, at change of characteristics of initial materials, composition of solution and technological mode of preparation , but at least:

- 1 time in 3 months - when determining the compression strength of heat-resistant  solutions;

- 1 time in 6 months - when determining the water-retaining capacity of water-containing solution mixtures, consistency (for solution mixtures with a grain size of not more than 0.63 mm), shrinkage of solutions for self-melting ties, self-stress or linear expansion ;

- 1 time per year - in determination of delamination of water-containing solution mixtures, tensile strength at bending, strength of adhesion with base, strength of glue joint at uniform separation. 

 Specific effective activity of natural radionuclides is determined  in the absence of raw material supplier data on value of specific effective activity of natural radionuclides in supplied materials, but at least 1 times a year. 

Design temperature of application for solutions containing anti-frost additives, limit temperature of application of heat-resistant solutions , viability, relaxability (for solutions from dry solution mixtures), deformation of shrinkage of waterproofing solutions and average density of heavy solutions are determined when selecting solution compositions. 

During acceptance and periodic tests of PCC, RSPI, IPS, the determination of quality indicators should be carried out when the amount of water and components specified in the accompanying document is added to the test solution mixture.  

RSGP is released and accepted by volume. The volume of the solution mixture established during loading shall be adjusted to take into account the sealing factor during its transportation, established by agreement of the manufacturer with the consumer.  

RSPI  is released and taken by  weight.  The amount of RPVs obtained from    the RPVs delivered in the vehicle shall be determined in accordance with Annex B, taking into account the estimated amount of water to be added to the RPVs to prepare the RPVs of the required mobility and density agreed between the user and the manufacturer. 

IPS mixtures are accepted by volume taking into account the coefficient of compaction during their transportation, established by agreement of the manufacturer with the consumer. Dry solution mixtures are released and taken by weight .

The consumer has the right to check the quantity and quality of the solution mixture in accordance with the requirements of this standard, as well as to demand from the manufacturer of the solution mixture the results of control tests in case   of technically justified controversial issues. 

The manufacturer shall inform the consumer of the results of the control tests in case of non-confirmation of the regulated values ​ ​ of the indicators no later than 3 days after their receipt.   [1].

Warehouse and cargo turnover of the enterprise

4.2.7.1 Warehousing

Sand warehouse.

The design of filler warehouses should be carried out taking into account the following conditions: acceptance and unloading of fillers from vehicles; submitting them to the warehouse; Storage in stock during the stock period delivery of aggregates to the mixing shop.

Sand enters the plant by road.

The design of binder warehouses should be carried out taking into account the following conditions: acceptance and unloading of binder from vehicles; submitting them to the warehouse; Storage in stock during the stock period delivery of aggregates to the mixing shop.

Lime arrives at the plant in car cement locomotives. Pneumatic unloaders are used to unload car cement locomotives, the most successful are suction pneumatic unloaders, which receive lime from car cement locomotives and supply it at a distance of 12 m to the pneumatic pump with a pneumatic hoist.

Pneumatic screw hoists are used to supply lime from the receiving bin to the silos of the warehouse.

Lime is unloaded via a wire to the warehouse bunker. Filters and cyclones are used to clean the air leaving the silos when they are loaded with lime, reception and delivery silos, under which collectors of dust sucked periodically by the pneumatic discharger are installed.

Level indicators are provided in silos for monitoring and automatic control of lime loading and unloading. Bottom of silos is equipped with aeration coarsening device. Lime is released from silos by means of bottom unloaders. The pneumatic screw pump carries out a continuous transportation process.

Silo warehouses provide protection of lime from humidification both during precipitation and at high air humidity. Elimination of drain is achieved by pumping lime in the form of aerosol from one compartment to another, for which one free compartment is always provided.  

Cement warehouse.

The design of binder warehouses should be carried out taking into account the following conditions: acceptance and unloading of binder from vehicles; submitting them to the warehouse; Storage in stock during the stock period delivery of aggregates to the mixing shop.

Cement comes to the plant in covered cars. Pneumatic unloaders are used to unload covered railway cars, the most successful are suction pneumatic unloaders, which receive cement from covered cars and supply it at a distance of 12 m to the pneumatic pump with a pneumatic hoist.

Pneumatic screw hoists are used to supply cement from the receiving bin to the silos of the warehouse.

Cement is unloaded via cement pipeline into storage silo. Filters and cyclones are used to clean the air exiting the silos when they are loaded with cement, reception and delivery silos, under which collectors of dust sucked periodically by the pneumatic discharger are installed.

Level indicators are provided in silos for monitoring and automatic control of cement loading and unloading. Bottom of silos is equipped with aeration coarsening device. Cement is discharged from silos by means of bottom unloaders. The pneumatic screw pump carries out a continuous transportation process.

Silo warehouses provide protection of cement from humidification both during precipitation and at high air humidity. Elimination of drain is achieved by pumping cement in the form of aerosol from one compartment to another, for which one free compartment is always provided. By reference to transport communications, the warehouse is rail.

Finished goods warehouse.

For the warehouse of dry building mixtures we design a closed non-heated building with lightweight construction structures.

The stock of finished products in the warehouse is 10 working days or 1406.25 tons.

The volume of products placed per 1 m2 of area, excluding passages, is 0.3 tons  . The warehouse area without trips is 4687.5 m2; coefficient taking into account passes between stacks 1.4. The area of ​ ​ the warehouse with passages is 6562.5 m2. The size of the warehouse is 72 × 96 m. Therefore, the area of ​ ​ the warehouse is 6912 m2.

4.2.7.2 Calculation of cargo flows

Calculations for cargo turnover and cargo flows of the enterprise and its workshops are drawn up in the form of a chess list (table). It shows all movements of goods carried out in the plant, which allows you to determine the external cargo turnover and the corresponding external cargo flows of arrival and departure, all internal (inter-company) cargo flows and the total cargo turnover of the plant .

Organization of production

3.1 Substantiation of production method

The production of dry mixtures is concentrated in a workshop measuring 24 x 36 m with a height of 13 m. At the top of the building there are 6 bunkers of raw components: 2 for cement, 2 for fractionated sand , 1 bunker for C3 addition, 1 for dump of non-fractional sand.

Cement silos are equipped with bag filters for dust collection during their pneumatic loading.

Main components are metered by weight, for which bunker scales are selected. From the hoppers, the components enter the scales sequentially one after the other with the help of two-speed screws. All supply paths are manufactured in a closed version, the bunker scales are equipped with an independent pressure filter, which allows returning the caught dust back to the process.

Dosing of additives is carried out manually in order to save money. Additives are weighed on trade scales, packed in bags and at the required moment they are introduced into the mixer through a funnel located a floor above. Additives are transported and stored in bigbags - soft containers with a bottom valve. One of the advantages of this package is that bigbag can play the role of a consumable bin from which the additive is fed to the scales.

2 circular blade mixers are selected as mixers. It ensures high-quality mixing of the mixture in the shortest time, the possibility of unloading without residue, ease of cleaning and is a recognized standard in the production of dry mixtures. Since it is planned to produce only three types of mixtures, it is recommended to use a mixer with an unloading valve. However, in this case, complete unloading is not achieved and the transition from a larger aggregate mixture to a fine aggregate mixture must be accompanied by cleaning. To minimize downtime, cleaning is carried out in the morning, and mixtures with coarse aggregate are carried out in the third stage.

Finished dry mixtures are packed by means of packing machines. They differ in material supply systems: aeration, pneumatic chamber and turbine. Aeration supply is not recommended for dry mixtures, as it causes segregation of their components. Pneumatic chamber supply is universal, however, when packing together with the product, a large amount of air enters the bag. This leads to the use of expensive perforated bags and a powerful aspiration system. Turbine supply is most widespread. Injection of the product is carried out by a turbine providing a high filling speed. The packaged products contain less air and occupy a correspondingly smaller volume.

Dry mixtures can be packed in bags of 1050 kg, bigbags of 5002000 kg, small packing of 1-5 kg. Bags are transported in packaged form. Automation of the process of palletizing and packaging products allows: to abandon the use of manual high-paid labor; significantly reduce transport downtime during loading and unloading operations; ensure the safety of bags in almost any number of overloads.

The plant is controlled by a computer control system, which usually has a two-level structure. The upper level, implemented on the basis of a personal computer, is intended for creating databases on recipes and components, generating reports on the production and consumption of components, displaying a mnemonic diagram on the monitor, displaying a message about failures and operation and acknowledging them, setting process parameters. The lower level is implemented on the basis of programmable controllers. Operators are designed to interrogate sensors and output control signals to actuators.

3.2 Development of the organizational and technological structure of the production process 3.6 Organization of auxiliary services of the workshop

The most important condition for the normal functioning of production, along with the provision of its materials, electricity, water, steam, etc., is the stable, uninterrupted operation of technological equipment. It is achieved by clear planning and well-organized implementation of the planned preventive repair system. The basis of the system is an annual schedule for the maintenance and repair of equipment, which is formed by the service of the chief mechanic of the enterprise. The organization of repair services, the determination of labor costs, the duration of repairs is based on the standards of the unified planned preventive repair system (ESPPR).

Labor intensity and duration of equipment repairs depend on their repair complexity. One unit of repair complexity of the equipment of the construction industry enterprises is accepted equal to 40 people for the mechanical part and 12 people for the electrical part, assigned to the SP as the tariff grid of the maker.

Heat engineering calculation of drum dryer for sand drying

In furnaces and dryers, very complex, responsible technological processes are carried out related to the drying and burning of materials and products, as well as to the melting of charge materials. Therefore, the issues of technological progress are inextricably linked to the improvement of the design of furnaces and dryers and their thermal work.

The design of the dryer depends on its technical purpose. For drying loose fine powder materials, various designs of continuous dryers are used - drum, pneumatic. They are selected depending on the properties of the material to be dried (humidity, particle size, density, the nature of the moisture connection with the material), as well as the requirements for the material to be dried, productivity, taking into account the technique - economic indicators of the selected apparatus. Drum dryers are most common. They are characterized by reliability in operation, ease of control using automation, the ability to use a variety of fuels.

It is a welded cylinder - a drum, on the outer surface of which bandage supports, stiffening rings and a drive toothed rim are fixed. The axis of the drum can be inclined to the horizon by 40-60.

Inside the drum, nozzles are installed, the design of which depends on the properties of the material to be dried. On the side of the loading chamber, a multi-lock screw nozzle, with a number of spiral blades from six to sixteen, depending on the diameter of the drum. When drying the material with high adhesion to the surface, chains are fixed at the initial section of the latter, with the help of which the cams are destroyed and the drum walls are cleaned. Percussion devices located on the outside of the drum can be used for the same purpose.

In dryers with diameter 1000-1600mm for material with good looseness and average particle size up to 8mm, a sector nozzle is installed. In the same dryers, for materials having increased adhesion or loose materials with an average particle size of more than 8 mm, lift-blade devices are installed. In dryers with a diameter of 1000-3500 mm for materials that are prone to sticking, but restore loose properties during drying, lift-blade transshipment devices and then sector nozzles are first installed.

The main material for the manufacture of dryers, loading and unloading chambers is carbonaceous steel. In technically justified cases, additional production of drums, loading and unloading chambers is partially or completely made of heat-resistant steels of special grades.

Automation of continuous dosing processes

The dosing process in the production of dry building mixtures is one of the main operations. The quality of the final product depends mainly on the correctness of the ratio between the starting components, i.e. the quality of the dosing equipment. Among the reasons that make it difficult to produce dry building mixtures with given properties are dosing errors of raw materials. 

For continuous production of mixtures, continuous dispensers are used, which consist of a control object - a feeder supplying material to the belt of the weighing conveyor and elements forming the main negative feedback. Dispensers can be referred to systems for automatically stabilizing the mass of material on the belt of a weighing conveyor, due to a change in the feeder capacity, or stabilizing the flow rate, due to a change in the belt speed.

Flow-controlled dispensers have a number of advantages over mass-controlled dispensers. Flow control has higher accuracy in steady-state mode, allows to apply optimal type of control action by means of change of belt speed of weighing conveyor and, as a result, to obtain even outflow of material, wide range of control and possibility to use standard devices of general industrial purpose as regulators.

The great potential for obtaining high accuracy and quality dosing has resulted in this type of dispenser being the most promising at present.

Based on the consideration of the dynamic properties of the structural elements of the dosers with flow control, Figure 5.1 shows their diagram reflecting the fundamental features of the dosing process.

In the dosing circuit, the power meter D measures the moment from the mass of material M. The signal from the output of the power meter is supplied to the EC multiplication element, which also receives the signal from the speed sensor of the TG tachogenerator. The comparison element subtracts the signals of the EP and the setter Z. The resulting mismatch signal is reduced by the RO regulator to zero due to a change in the speed of the conveyor belt V. The dispensers use general-purpose regulators, which reduces the task of ensuring high-quality dosing to the determination of their optimal settings.

The presence of a multiplier element and a variable lag link in the control loop does not allow using the developed analytical methods of automatic control theory to calculate the system in a general form. Therefore, it is necessary to identify a number of tasks that will allow to make fuller use of the potential of the dosing systems under consideration.

Architectural and construction part

7.1 General Part

The diploma project was developed for the construction of a plant for the production of dry building mixtures. The place of construction is the city of Mozyr.

Construction decisions of the project were made on the basis of technological tasks, a master plan with housed buildings and structures, and taking into account the nomenclature of construction products used in the construction region.

Design temperature of external air is minus of 29 wasps (temperature of the coldest day security 0.92).

The standard value of wind pressure is 23 kg/m2 for the first region of Belarus, and the standard value of snow cover weight is 120 kg/m2 for the IIB region of the country.

No groundwater was found.

7.2 Plot Plan

The construction of the facility is planned in the industrial district of the city of Mogilev. The layout and design scheme are as close as possible to the requirements set by modern standards, taking into account the purpose of the building, its location, features of groundwater, meteorological and other conditions that directly affect the duration of suitability of the building for normal operation.

The layout of the plot plan is made taking into account the specifics of the terrain, rational use of the allotted territory, requirements [12,13]

The general plan of the enterprise reflects the spatial placement of buildings, structures, transport and engineering communications on the territory allocated for the enterprise, taking into account the terrain.

The general principles for developing master plans are:

- Effective use of the territory;

- reducing the length of flows;

- elimination of flow crossing;

- ensuring the clarity of production links;

Calculation of the master plan area.

7.3 Volumetric planning solutions

The designed workshop for the production of dry building mixtures has dimensions of 24x36 meters. Production premises are selected depending on the size of the process lines located in the workshop, the size of the equipment and the conditions for its placement in compliance with the required passages and passages.

  The main type of industrial building is frame, this is due to the presence in many industrial buildings of large concentrated loads, shocks and shocks from technological and crane equipment.

2 entrances are designed in the shop.

7.4 Structural Part

Design solutions were developed taking into account the existing nomenclature of prefabricated reinforced concrete products and standard design solutions.

The selection of the main load-bearing and enclosing structures is carried out taking into account the unification of spans in order to reduce the number of types.

Reinforced concrete structures are characterized by high durability and incombustible and insignificant deformability .

Overall diagrams of the main workshop building: 

the pitch of the columns is 12 meters;

span width is set depending on dimensions of process equipment taking into account passages and passages. We choose a span - 24 meters.

The foundations for the bearing elements are designed monolithic glass-type. 

7.5 External and internal networks

Water supply system

The source of centralized water supply is the existing networks. Water quality in the underground source meets the requirements [16].

The water supply network, to which the design building is to be connected in accordance with the specifications, is laid along the construction site from cast iron pipes with a diameter of 100 mm. The network has fire hydrants.

Rain sewer

The rain sewer system, according to the project, is connected to the city.

Technical solutions for heating and ventilation provide the microclimate parameters in the premises within the permissible limits, in accordance with [16, 17].

Heating of buildings is mainly provided by water heating systems.

Ventilation

All rooms are provided with plenum ventilation with mechanical and natural motivation.

In the rooms, as a rule, a balance is provided between the flow rate of supply and exhaust air.

Automatic control is provided for ventilation systems and heat supply systems of heaters.

Noise protection of premises

Ventilation system is equipped with silencers. Fan casing and air ducts within ventilation chambers are covered with vibration absorbing mastic. Fans are connected to the duct network by flexible inserts. Ventilation units are installed on vibration base.

Light sources. Lighting fixtures

Two types of lighting are accepted: evacuation and local. Power distribution is provided through power and lighting boards with circuit breakers.

Evacuation lighting is separated from the number of general lighting lamps and is fed by independent groups regardless of the working lighting network.

Luminaires are selected according to existing nomenclature types, environment characteristics and space assignments.

Economic part

8.1 Calculation of raw materials, materials and electricity costs

The requirements for raw materials and materials will be calculated in accordance with the calculations carried out in the process section. Calculation of demand for raw materials and materials

Environmental protection

The environmental management system ensures that the organization addresses environmental issues by managing available resources, allocating responsibilities and continuously assessing performance. The environmental service of an enterprise must competently monitor and direct its activities in order to comply with environmental legislation, educate and involve all units of the enterprise in its work. This can be either one person or a bureau (department), in which each employee is responsible for his/her area of work.

The environmental service has to have: the provision on security service of the environment (OOS) of the enterprise, duty regulations of workers where their powers and duties and also the necessary legal and regulatory base which constantly is updated and replenished are defined. The environmental service reports directly to the head of the enterprise or to the chief engineer.

Environmental policy is determined by the top management of the organization, and the service should develop a program to achieve target and planned environmental indicators (use of water resources, reduction of emissions, discharges, reduction of waste generation, minimization of environmental impact). But it cannot be considered that the responsibility for environmental protection lies only with the environmental service, and other parts of the organization should also be responsible for this.

The duties, responsibilities and powers of all employees must be defined, documented (by order of the enterprise) and communicated to those concerned. Officials are obliged to know that they bear property, disciplinary, administrative and criminal liability for environmental offences, causing harm to the environment and human health.

It is necessary that all employees whose work can significantly affect the environment receive appropriate training and understand what the real or potential impact of their activities on the environment is. They should have the necessary knowledge, techniques and skills required to carry out their tasks competently, as well as an understanding of the negative environmental impacts that their activities may have if they do not perform correctly.

Each employee of the enterprise must know and comply with environmental legislation (within his/her competence), his/her job descriptions and be held liable in case of violations. Requirements and regulations of environmental legislation may also be included in a separate section in technological processes. The enterprise may have special instructions on certain aspects of air and water protection, waste collection and disposal.

For each unit, annual action plans should be developed that are aimed at improving the environmental situation, and the implementation of the planned work should be constantly monitored. Internal communication between different levels and business units is needed. Each subdivision shall submit to the environmental service monthly reports on waste generation and disposal, confirmed by delivery certificates, consignment notes or other documents, reports on the operation of stationary emission sources, PSG, water consumption, etc. This is necessary to draw up payments, state reports, control the generation and disposal of waste.

The ecologist needs to constantly monitor the work of the units to comply with environmental legislation. These checks should be carried out with the involvement of other specialists responsible for this area of ​ ​ work (heads of departments, technologists, etc.). If violations are identified, measures are planned to eliminate them.

Control of atmospheric air, sanitary protection zone, discharges of pollutants, waste composition should be carried out by a certified laboratory (own or under contract) in accordance with plans and schedules. Environmental service personnel shall be present during sampling. All analysis results should be sent to the Environmental Service to summarize and analyse the implementation of maximum allowable discharges (PDS) and emissions (IPA) standards. According to the consolidated data, reports and proposals for improving environmental protection are submitted to management.

The environmental service should also monitor the timely development of PDS, MPA standards, limits for the placement of production and household wastes of the enterprise, as well as the availability of permits, obtaining the necessary licenses on time (for waste management, water use, etc.). The standards of PDS, IPA, limits for the placement of industrial and household waste of the enterprise can be developed by the environmental service itself or by the competent organization (under the contract).

The enterprise needs to make export, utilization, placement of industrial and consumption waste under the contract with the organizations which have licenses for this type of activity. This will help avoid trouble with regulatory authorities. The main provisions given in GOST 17.2.3.02 were taken into account when designing and organizing the production of dry building mixtures.

Placeholders:

- Equipment transporting dust materials shall be equipped with aspiration systems.

- Open loading openings of hoppers shall be enclosed along the perimeter.

- On the side of loading with hoppers, a baffle bar with a height of at least 0.4 m shall be provided by road vehicles.

- Conveyor service passage width shall be not less than 0.7 m.

- Width of passes for assembly and repair of conveyors shall be not less than 0.7 m

- Height of passages along conveyors shall be not less than 1.8 m.

Mixing compartment:

- Equipment transporting dust materials shall be equipped with aspiration systems.

- Control of all processes shall be remote.

Finished goods and production waste warehouses:

- Height of stacking of articles and materials during storage in horizontal position must not be less than 2.5 m.

- Minimum width of passages between stacks shall be not less than 1.0 m.

- The width of the passages between the rows of stacks and the dimensions of the vehicle shall be at least 1.5 m.

- Transverse passages, not less than 1.0 m wide, shall be provided at least every 25 m, between stacks breaks of width 02 -0.4 are accepted.

- For warehousing and shipping of products in stacks, with a height of 1.6 m or more, inventory stairs shall be provided that meet the requirements of GOST 12.2.012.

General requirements for electrical equipment and automation:

- All starting equipment and protection equipment shall be installed on open panels located in closed, dust-free and insulated shield rooms, to which clean air is supplied from special ventilation chambers. It is allowed to install the starting equipment in the production premises, provided that the requirements of the relevant regulatory documents are met.

- Complex low-voltage electrical control devices shall comply with the requirements of GOST 22783.

- Inside the sections, the mechanisms must be connected to each other by dependent units in the direction opposite to the technological process.

- To improve the reliability of the CAT operation on belt conveyors, a speed relay shall be provided.

- Operator rooms shall be located taking into account ensuring maximum review of process equipment operation, ease of its management, shortest distance to equipment and electric trails, as well as compliance with labor protection rules. The operating rooms shall be equipped with double-sided loudspeaker communication with service areas..

- The automation project establishes remote control of technological processes, as well as operating and emergency alarms.

Sanitary and hygienic requirements for working conditions at workplaces:

- Measures as per GOST 12.1.003 and SNiP P1277 shall be provided for reduction of noise level at roadblocks during equipment operation.

- The general vibration levels at the roadblocks during operation of process equipment generating vibrations shall comply with the requirements of GOST 12.1.012 and shall not exceed 87101 dB.

- To eliminate the harmful effect of vibration at workplaces, design and technological operations specified in the documents should be provided.

- Levels of local vibration transmitted to the hands of pneumatic and electric hand tools shall comply with the regulations.

Measures for dusting and aspiration of process and transport equipment:

- Transportation of powdered materials should be provided in closed transport devices.

- In tanks - hoppers, silos provide automatic indicators of the upper and lower level in order to exclude emergency.

 When loading hoppers using pneumatic conveying, it is necessary to provide cyclones - unloaders with their subsequent connection to the aspiration system:

- Discharge cyclones shall be equipped with gates preventing air discharge into the hopper cavity.

- Dust collecting and aspiration systems shall be blocked with process equipment starters

- All process equipment, the operation of which is accompanied by dust release, shall be equipped with hermetic shelters, having funnels for connection to aspiration and dusting units.

- In order to prevent the departure of the saw from the shelter, it is necessary to provide in it a vacuum of at least 2 Pa.

For a group of hoppers loaded with different materials by means of belt conveyors, individual aspiration shall be provided by connecting each hopper to an aspiration system.

 The aspiration air must be 99% cleaned before being released into the atmosphere.

Also, as a measure limiting the content of pollutants in the environment, the maximum permissible concentration (MPC) is adopted. In the practice of rationing and for the sanitary assessment of the degree of pollution of the air and water medium, the maximum permissible concentration of harmful substance in the air of the working zone (PDKrz, mg/m3) is used. This is such a concentration of substance in the air that does not cause diseases or abnormalities in the state of health found by modern research methods directly in the process of work or in the long term for those working during daily inhalation for 8 hours. A working area is considered to be a space up to 2 m high above the level of the floor or platform on which there are places of permanent or temporary stay of workers.

The limit values of MPC in accordance with the current GOST 12.1.00588 "General Sanitary and Hygienic Requirements for the Working Area Air" are indicated in Table 10.1.

Innovative solution for modification of dry building mixtures

Dry construction mixtures in a relatively short period of time won the recognition of builders on the domestic market and almost completely replaced the formed solution mixtures. Their consumption volumes increase annually, and the nomenclature is constantly expanding. The scope of application of the CCC is diverse and includes the following types of work: installation, masonry, tile, trellis, hydro and heat insulation works, flooring, etc.

The use of basic principles of physicochemical mechanics has led to the creation of polymer fibers having a reaction surface for building composites, which is important in the production of dry building mixtures. Polymer fibers are designed to obtain a denser solution at low binder consumption, to increase the physical and mechanical properties of the coating layers, to increase water retention and reduce intrinsic destructive stresses arising from hardening of the construction composite, etc. It will be appreciated that the 813 μm fibers produced at a length of 1.53 mm are components of adhesive compositions, pastes, patches and other materials.

The process developed by the company in the production of fiber involves directional physical, chemical and composite modification to impart mechanical strength to the fiber and chemical reactivity of the fiber surface to cement hydration products.

The result of research work was the development of a fiber of a coaxial structure, consisting of a strong and rigid core and an active shell, which enters into chemical interaction with hydration products.

Properties of cement-containing composite materials reinforced with polymer fibre are characterized by parameters of contact zone, which depend on specific surface area of fibre, and parameters related to chemical composition of modifying additives in fibre shell and uniformity of distribution of microfibers in volume of composite material.

This idea in the chemistry of a solid body, the formation of its structure should be attributed to the scientific concept of the twentieth century.

It is important not only because it explains the multifactorial interaction of dispersed phases in dispersion media, but also because it allows you to control the connections between the chemistry of the surface of solids and the physical chemistry of cement hydration, as well as the colloidal chemistry of its closers. In this aspect, the theory of hydration and hardening of binders by the donor-acceptor mechanism becomes relevant. It contains energy and thermodynamic conditions of interaction in binding systems, giving ideas about the driving forces that determine the meaning of modern concrete technologies.

The properties of the mixture should be controlled at the electronic level of the structure of matter, as well as its strength.

This theoretical position in recent years has received a convincing practical development in the technology of high-strength concrete, protective and finishing durable coatings of buildings and architectural monuments, in the production of dry construction mixtures for multifunctional purposes.

An important part of the problem of creating new cement composites is to obtain information about the interfacial physicochemical interaction of the cement matrix with the surface of the fiber filler, as well as the issue of the effect of this interaction on the mechanical characteristics of the cement composites as a whole.

Values of values of interfacial and contact energy of surfaces determine priority of micro-reinforcement technology. We consider the specific surface of polymer fibers, their acid-base centers as energy carriers as an intense feature of a hardening system, which is comparable to the concentration of structure-forming elements of this disperse system.

When placed on the fiber surface in an initiative state, the terminal functional groups and inorganic amorphous modifiers act on the hydration process to form crystallized splices of crystalline hydrates along the fiber extension.

It has been found that polymer fibers catalyze the reactions of formation of calcium hydrosilicates of group CSH (II).

These interphase systems form the basis of the resulting dense contact zones and the entire matrix portion of the mixture.

An increased concentration of crystalline hydrates near the fiber-cement stone phase interface strengthens the cement matrix.

The integral strength of the cement composite in the presence of polymer fibers is determined by a number of factors, where the value of adhesion of the matrix to the surface of the fiber and the value of cohesion of the interfacial layer of neoplasms take on significant importance. At a sufficiently high concentration and specific surface of the fibers, as well as at the appropriate thickness and a certain mineralogical composition of this layer, the third phase component begins to play a role with its dependence on stress-strain characteristics.

It is determined that the addition of activated fibers increases the dispersion of the cement paste and leads to an increase in its activity and adhesion properties. Active pozzolan centers on the surface of the fiber contribute to the rapid formation of plastic strength due to increased solubility of the SiO2 and subsequent intensification of the formation of calcium hydrosilicates.

The microarming and modifying properties of the polymer fiber ensure the shrinkability of materials manufactured using it in the production of CCC for various purposes, when drying which the problem of shrinkage and crack formation is especially relevant. Dry mixtures modified with polymer fibers make it possible to obtain the required properties of cement systems: fluidity, adhesion strength, necessary hardening kinetics, which, in turn, provides high operational properties of hardened cement stone - durability, frost, corrosion and water resistance.

A specific property of plaster solutions is slipping or draining from the surface, which is associated with the features of their use - on a vertical surface in layers of various thicknesses. During the time until the solution has lost its plastic properties, gravity can cause the layers of solution to shift relative to each other, resulting in deformation and discontinuity of the plaster coating. Solutions with reinforcing fibers have high cohesive connectivity of the structure, high adhesion to the base and rapid gain of plastic strength, which prevents the plaster mixture from sliding.

Modern construction technologies are focused on the use of dry mixtures, which are characterized by stability of properties. Introduction of polymer fibres as functional component of solution mixture significantly increases efficiency and efficiency of cement compositions, improves their construction and technical properties. The wide range of applications of these mixtures is mainly due to the presence of polymer fibers in their composition. On average, the dosage of polymer fibers in dry mixtures is about 0.25% by weight, varying in some ranges depending on their purpose. In closed form, they are very plastic, easy to apply and have good adhesion to various surfaces. Polymer fibers increase water-retaining capacity of closed mixtures, enhance their structure formation and eliminate shrinkage during hardening. Mixtures modified with polymer fibers are atmospheric and frost-resistant, which allows them to be successfully used both for external repair and finishing work, and for repair of facades.