Granulator - diploma project

Contents

Introduction

1. Literary Search:

1.1. Theoretical foundations of granulation;

1.2. Elastic-viscous properties of feedstuffs;

1.3. Friction of feedstuffs;

1.4. The pressing equation;

1.5. Physical and mechanical properties of feedstuffs during granulation;

1.6. Increased durability of ring dies of feedstock pelletizing presses;

1.7. Wear of working surfaces of annular dies;

1.8. Wear of inlet cavity and cylindrical part of dies of annular dies;

1.9. Conclusions

2. Analysis of design features of pelletizers produced by various countries of the world:

2.1. Conclusions

3. Patent study of the object

4. Description of the designed object

5. Calculations confirming the operability of the structure:

5.1. Initial granulator data;

5.2. Technological calculation of granulator matrix;

5.3. Power calculation of die shaft-pipe;

5.4. Power calculation of roller support axis;

5.5. Calculation of the most loaded rollers;

5.6. Calculation of section of cut stud;

5.7. Calculation of compression spring for blades;

5.8. Calculation of V-belt matrix transmission;

5.9. Calculation of the press-granulator on the computer, its results and analysis of dependencies detected as a result of the calculation

6. Automation of the press granulator:

6.1. Description of operation of electrical control circuit

7. Calculation of economic efficiency when introducing a pelletizer into production:

7.1. Purpose, field of application, design features of the designed machine;

7.2. Technical and economic indicators of the modernization project;

8. Occupational safety and safety during operation of the pelletizer:

8.1. Substantiation of the need to work out labor protection issues;

8.2. Ensuring safety, automation of technological processes and equipment;

8.3. Electrical safety, protection against static electricity;

8.4. Safety of pressure equipment;

8.5. Ensuring safety of installation, commissioning and repair works;

8.6. Noise and vibration control;

8.7. Explosion and fire safety;

8.8. Provision of standard meteorological conditions at workplaces;

8.9. Control of air dust content in the working area;

8.10. Provision of standard level of illumination at workplaces

Literature

Applications:

Appendix No. 1- "Assignment to the diploma project";

Appendix No. 2- "Specifications";

Introduction.

When creating a strong feed base for the development of livestock and poultry farming, along with the expansion of fodder crops and their growth in yields, it is very important to expand the production of compound feed.

The rational feeding of farm animals, birds and fish largely determines their growth, development and productivity. Each feed product has both advantages and disadvantages. There are practically no products in which there are all the nutrients necessary for the animal body and in the right amount. Therefore, feeding such products is unproductive and requires excessive consumption of feed. However, knowing the characteristics of individual products, you can make a mixture in which the main nutrients, vitamins, etc., will be in a favorable ratio. Such a mixture is called a combination feed, or feed combination.

Increasing the production of feedstuffs is thus the most important task of the feedstuff industry. With an increase in the production of feedstuffs, it is necessary to improve their quality and expand the range. In particular, it is necessary to increase the production of granular feedstuffs that mechanize the feeding process of birds and animals, improve the loading, storage and transportation conditions of feedstuffs, improve the safety of nutrients, vitamins and other biologically active substances in them, as well as reduce the races of dust and self-sorting. In this regard, feed mills are equipped with special granulation equipment.

In our country, plants are manufactured and used: DG1; B6-DHA; B6DGE; E8-DGB having different capacity and drive power. Despite these facilities, there is a need to develop new equipment for feed pelletizing. This is due to the fact that the press granulators currently used in the country's feed mills no longer meet the increased requirements for the quality of granular feed, are morally outdated, have insufficient productivity, high material consumption and, therefore, large dimensions and mass, they do not have, or control and control of the operation of the press granulator in automatic mode is difficult.

This thesis addresses both theoretical issues of granulation and issues of practical importance for the calculation and possible further production of the line equipment.

1. Literary search.

1.1. Theoretical foundations of feedstuff granulation.

Enterprises of the feed industry produce feed feed, which is a homogeneous mixture of various types of purified and crushed to the necessary extent raw materials of vegetable, animal and mineral origin. The combination of components in feedstuffs provides the most efficient absorption of nutrients contained in the feedstock. Crumbling feedstuffs have disadvantages, especially when transported over long distances. If the composition of fodders includes products such as meat or fish flour, then their mold and rot begin quite quickly. The most effective means of combating these disadvantages is the granulation of feedstuffs in special machines.

Granules from feedstuffs are obtained on presses in the form of cylindrical columns or cubes. They are a pressed compound feed with a diameter of 2 mm to 20 mm and a height of 1.5 to 2 diameters (Fig. 1). Size of granules is chosen by type and age of animals and birds, for feeding of which feed is used.

Granular feedstuffs belong to the group of full-feed feeds, which can be used without the addition of other feeds. The use of this food product contributes to the growth of livestock and poultry productivity. Granular feed is widely used to feed poultry, pigs, cattle, sheep, etc. They are also very effective for feeding fish, but in this case the granules should have increased water resistance, ensuring the swelling of feed in water for at least 15 minutes, instead of 3 minutes for ordinary granules.

Advantages of granular feedstuffs over loose feedstuffs:

- high nutritional value, because in them are evenly distributed and concentrated various nutritional components included in the composition of feedstuffs, as well as necessary additives that increase the value of granules (molasses, vitamins, etc.);

- the ability to fully mechanize the feeding process, which increases the productivity of labor, maintenance personnel on farms;

- reduction of feed consumption as a result of reduction of losses of powdery part of combined feed during transportation and distribution;

- absence of self-sorting of individual components included in feed mix;

- better safety as a result of reduction of the surface of contact of the product with the external environment.

Granulation eliminates the separation of the mixture - in this is the main importance of the process. In addition, granular combined food is well absorbed during feeding. It has low losses on spraying, promotes the introduction of all constituent feed into the body of animals. Granular combined feed has greater air access, so when stored, it is less threatened by the occurrence of self-heating foci.

Conclusions.

1. Literature on problems and theory covers almost all issues that arise in the design and operation of press granulators.

2. The loose feed produced by the feed industry has disadvantages, the most effective means of combating which is the granulation of feed.

3. The granulation process is based on four main operations: conditioning or hydrothermal treatment of the mixture, granulation of the mixture, cooling of the granules, classification of the product by size. In the feed mill industry, two granulation methods are used: dry and wet. Most granular feedstuffs are produced by a dry method.

4. The greatest effect of conditioning is obtained at a steam pressure of 0.6-0.8 MPa and a temperature of 160170 ° C, so the mixture is heated to 7080 ° C. The optimum moisture content for the granulation process is 1518%.

5. For pellets obtained on matrix presses, the coefficient of elastic expansion equal to the ratio of the volume of pellets after complete expansion to its volume under pressure is 1.1-1.25.

6. As a result of dissipation of energy during granulation, stresses in the pressed material are reduced, that is, stress relaxation occurs. According to the theory, the effects of Boltzmann's stress during relaxation change according to equation (1.5) and for optimal granulation conditions at a pressing pressure of 7.050 MPa, the relaxation time is 1532 seconds, and the residual voltage is 2.8-1.2 MPa.

7. For optimal granulation conditions, the values ​ ​ of the external friction coefficients of the combined feed for steel should be taken within the limits of: static-0.2-0.5, dynamic-0.1-0.3, and the values ​ ​ of the coefficients of the internal static-0.4-1.0, dynamic-0.25-0.7.

8. The main indicator characterizing the forage pressing process is the density of the obtained granules. Equation (1.10) is the basic equation or the law of forage pressing, reflecting the physical nature of the process and determining the dependence of the normal pressing pressure on the density of the pellets.

9. The matrix is the most important part of the pelletizer, but its durability is insufficient and should be increased.

10. The wear of the contact surfaces of the die is due to the granulation process itself and occurs along the working surface of the die, the inlet cavities and the cylindrical part of the dies. At the same time, the smaller the diameter of the dies, the less durable the matrix.

11. The feedstock granulation process is characterized by the lowest energy consumption (100130 A load at a press capacity of 711 t/h) and the obtained quality of the produced pellets when the surface of the inlet cavities of the dies assumes a geometric shape close to the surface of the torus part during natural wear.

6. Automate the operation of the pelletizer.

Automation is a branch of science and technology that covers the theory and principles of building means and systems for managing production processes that operate without the direct participation of a person. Automation is the basis of automation.

Automation is called the stage of development of machine production, characterized by freeing a person from direct performance of functions by a technical device.

The feed industry is faced with the tasks of increasing labor productivity and production efficiency, increasing production of products of consistently high quality. To accomplish these tasks, it is necessary to widely implement automation devices and tools, to create efficient automatic and automated process control systems (APCS). The use of microprocessors and microcomputers to control the process of headlining feedstuffs opens up new possibilities for high-efficiency automation of feedstuff production. The use of microprocessors and microcomputers extends the functionality of equipment, control systems, significantly improves the reliability of their operation and ultimately positively affects the quality of products.

The successful functioning of technological processes, including the process of pelletizing feedstuffs, the production of high-quality products can be ensured only with the large-scale implementation of the automation of feedstuff production, in which the control and control functions are transferred to instruments and automatic systems.

Factors of increasing the economic efficiency of automation include: improving the quality of products, reducing the costs of raw materials and various types of energy, reducing production waste, increasing labor productivity, increasing the volume of products produced, improving the working conditions of service personnel.

6.1. Description of the operation of the electrical control circuit for the operation of the pelletizer.

The electric motors connected to the circuit are powered from a three-phase AC network with a voltage of 380 V. The control circuit is powered from an AC network with a voltage of 220 V.

The following motors are included in the circuit diagram: M1 motor of the press drive; M2 mixer drive motor; MZ motor of feeder drive.

Electrical diagram provides for control of MKCH-10 press-granulator operation in manual and automatic modes. Manual control is used during testing and initial start-up of the plant. The main mode of operation is automatic.

Consider the manual operation of the plant. Switch SQ1.1 is set to "Manual control" position. Start of M1, M2, MZ motors is performed by pressing of corresponding push-button switches SB2.2, SB2.3, SB2.4. Voltage is applied to coils of magnetic starters KM1, KM2, KM4 and this leads to closure of their contacts. When the contacts KT2, KTZ, KT4 are closed, the corresponding motors M1, M2, MZ are started. The starting of the motors is indicated by the light signalling HL4, HL5, HL6, which is simultaneously switched on by contacts KM1, KM2, KMZ. Electric motors are stopped using push-button switches SB1.2, SB1.3, SB1.4.

In the automatic mode, the start of the press pelletizer motors occurs sequentially, with a delay in time after the start of the press motor. Press motor start-up is possible at steam pressure in steam line above 3.5 kg/cm2 (0.35 MPa) and closed door of press section. Stop in automatic mode is performed in reverse order with delay of time after stop of feeder drive motor required for production of remaining product.

Let's take a look at the installation in automatic mode. To operate in automatic mode, set the SQ1.1 switch to Automatic Control. Operation of the plant motors in automatic mode is performed in the following order. The motor M1 starts when the KTZ relay is closed, the mixer drive control circuit is closed and the motor M2 is turned on through the contact KM1, and the feeder drive control circuit is turned on through the contact KT4, which is closed by the contact KM2, which turns on the motor MK. The start of the motors is indicated by the light alarm HL4, HL5, HL6. Serviceability of light signalling is checked by pressing SB2.5.

During operation, if the steam pressure drops below 0.35 MPa, the feeder motor stops. Stop occurs after 4.5 minutes from the moment of descent. This is done by means of circuit-on and emergency disconnection of control circuit - through contacts of time relay KT1.

Control of air dust content in the working area.

During the process, for example, when loose feed is supplied for granulation, dust can be released into the production room. To remove it, the pelletizer has an aspiration nozzle with which it is connected to the aspiration network. According to GOST 12.1.00588, the maximum permissible dust concentration should be no more than 6 mg/m3; hazard class-4.

Dust-laden air is cleaned in filters or cyclones before being released into the atmosphere. To ensure dust tightness of the internal cavity of the electric cabinet, the consuming enterprise must supply clean air to the special connector, which generates overpressure of 20 kPa (0.2 kgf/cm2) through the filter reducer installed in the cabinet.

8.10. Provision of standard level of illumination at workplaces.

Lighting the workplace of maintenance personnel is an important factor in improving working conditions. Properly executed lighting reduces fatigue, as a result of which the quality of work is improved and safe conditions are created for it.

Lighting standards are adopted in accordance with SNiP 230595 "Natural and artificial lighting":

- characteristic of visual work - general observation of the progress of the production process (constant );

- category visual rabotyVIII;

- sub-stage of visual work-a;

- independent of background characteristic and object contrast with background;

- illumination (lux) at artificial general illumination 200;

- natural illumination coefficient (SEO) at natural lateral illumination - 0.3%;

-KEO at combined lateral illumination - 0.2%. Natural lighting is carried out at the expense of windows.

In order to illuminate the premises in the evening, luminescent lamps are the most hygienic and more economical.

We use luminaires in the moisture-blast-proof version for luminescent lamps of the PVL 2x40 type. Emergency lighting is provided, providing illumination of at least 5 lux. Because in case of emergency shutdown of working lighting, it is possible to evacuate people from the building, then evacuation lighting is provided, which provides illumination of at least 0.5 lux. For emergency and evacuation lighting, fluorescent lamps of the LSP18 type are used. Emergency and evacuation lighting luminaires are connected to a network independent of the working lighting network. Off-duty lighting shall be left at 35% of the working time. For on-duty lighting, we highlight part of the lighting fixtures of working lighting.