Development of welding technology and flaw detection methods for a carbon filter V = 21m3.

Contents

INTRODUCTION

1. PROCESS PART

1.1 Description of welded structure

1.2 Characteristics of the article

1.3 Fabrication and Acceptance Specifications

1.4 Strength calculation

1.5 Characteristics of materials and their weldability

1.6 Selection of welding method and welding equipment

1.6.1 Welding in protective gas

1.6.2 Flux Welding

1.6.3 Selection of welding materials

1.6.4 Selection of welding modes

1.6.5 Modes for automatic welding

1.6.6 Modes for mechanical welding

1.7 Selection of welding equipment

1.7.1 Welding equipment for semi-automatic welding

1.7.2 Welding equipment for automatic welding

1.8 Selection of standard equipment

1.8.1 Process Description

1.8.2 Product manufacturing process diagram

1.8.3 Characteristics of procurement operations

1.8.4 Technical rationing

1.9 Quality control of welded joints

2. DESIGN PART

2.1 Selection of process equipment

2.2 Calculation of roller support reduction gear box

3. ECONOMIC PART

3.1 Calculation of process and total cost of the article

for basic and projected versions

3.2 Calculation of the item price according to the basic and projected version

3.3 Calculation of capital investments related to implementation of new welding process

3.4 Calculation of economic effect and efficiency indicators

Welding Technology Replacement Project

3.5 Summary technical and economic indicators of the project

4. Analysis of hazardous and harmful production factors. Measures to improve working conditions

4.1 Microclimate

4.2 Electrical Safety

4.3 Noise

4.4 Radiation

4.5 Emergency Resilience

CONCLUSION

LIST OF LITERATURE

Summary

In thesis on "Development of welding technology and methods

defectoscopy of the coal filter V = 21m3., "The issue of assembly technology, welding and methods of flaw detection is being considered.

The diploma project contains 139 sheets of explanatory note, 10 drawings and posters, 25 tables, 12 drawings.

The project presents solutions to the process of welding of the item, calculations of the process modes of mechanized and automated welding, selection of welding equipment, modern methods of control of welded joints are presented.

The diploma proposes non-destructive testing methods and equipment that accelerate the process of searching for defects and reduce the harmful effects of ionizing radiation on personnel.

To increase productivity and improve working conditions for workers, as well as improve the quality of welds, mechanized welding in the environment of protective gas was replaced by automatic welding under a flux layer. At the same time, material resources are saved due to the use of less qualified personnel and faster productivity.

The calculations given in the diploma project showed the economic efficiency of technical solutions when they were introduced into production.

Economic efficiency is 868731rub.

Introduction

The development of the gas, oil, chemical industry requires the creation of new highly efficient, safe and reliable technological devices. The use of substances having explosion, fire hazard and harmful properties, the conduct of technological processes at high temperature and under high excessive pressure makes it necessary to study in detail the issues related to the strength and reliability of the units and parts of the devices, with the choice of protective means for maintenance personnel. Petrochemical engineering is tasked with designing, creating and producing high-performance equipment. Petrochemical engineering makes a great contribution to the development of the fuel and energy complex of our country. In accordance with the development plan of the Ministry of Energy of Russia for the development of gas chemistry and petrochemicals until 2030, a significant increase in Russian production is expected, aimed at increasing domestic demand. The volume of investments until 2030 in the development of oil and gas chemistry will exceed 1 trillion rubles. Russian petrochemical companies are implementing large investment projects, accompanied by large-scale purchases of industrial equipment. The products of domestic engineering are often either not produced or cannot withstand comparison with foreign analogues in terms of efficiency, energy intensity, reliability, cost and service life. Increasing the volume and quality of production of petrochemical equipment in Russia is an important task of machine builders.

Welding is the process of producing permanent compounds of materials by establishing interatomic bonds between welded parts during their local or plastic deformation, or the joint action of both. By welding, homogeneous and heterogeneous metals and their alloys are combined, metals with some non-metals (ceramics, graphite, glass, etc.), and even plastics.

Welding is an economically profitable, high-performance and largely mechanized technological process, widely used in almost all branches of mechanical engineering.

Physical essence of welding process consists in formation of strong bonds between atoms and molecules on joined surfaces of blanks. To form compounds, the following conditions must be met: cleaning welded surfaces from impurities, oxides and foreign atoms adsorbed on them; energetic activation of surface atoms, facilitating their interaction with each other; convergence of welded surfaces over distances comparable to interatomic distance in welded workpieces.

Depending on the form of energy used to form the weld joint, all types of welding are divided into three classes: mechanical, thermal and thermomechanical.

The thermal class includes types of welding carried out by melting using thermal energy (arc, plasma, electric slag, electron beam, laser, gas, etc.).

Thermomechanical class includes types of welding performed using thermal energy and pressure (contact, diffusion, etc.).

The mechanical class includes types of welding carried out using mechanical energy and pressure (ultrasonic, explosion, friction, cold, etc.).

Welding is a leading technological process in mechanical engineering. Metals of any thickness can be welded. The strength of welded joints is not inferior to the strength of the base metal, but in many ways exceeds it. Thermal processes combine all methods of melting welding.

The inventor of electric arc welding is the outstanding Russian inventor Nikolai Nikolaevich Benardos (18421905) in 1882. In his invention N.N. Benardos used the idea laid down in the works of the Russian physicist Vasily Vladimirovich Petrov (17611834), who in 1802 discovered the phenomenon of an electric arc and pointed out the possibility of its use for melting metals. N.N. Benardos focused on the development of a method of welding with a non-consumable electrode. Such welding is called welding according to the Benardos method. The essence of the method was that current was passed between the welded article and the carbon rod (electrode) from the accumulator battery and an electric arc arose. The arc melted the edges to be welded, and additional metal in the form of a rod was introduced into the arc and, melting in it, filled the gap.

Further development of arc welding is associated with its mechanization. Already in the early 20s. special mechanisms are being created to automate the welding and surfacing process. A new stage in the development of automatic arc welding began in the late 30s, when, under the leadership of E.O. Paton, automatic welding under a flux layer was developed in its modern form. The initial idea of ​ ​ flux welding was proposed by N.G. Slavyanov, but as any idea that overtakes its time, it did not receive recognition and development during the lifetime of the inventor.

In the late 40s. industrial application received the method of arc welding in protective gases. The idea of ​ ​ using gases to protect the welding zone was first carried out by the American scientist Alexander in 1928. But then, due to the difficulty of producing protective gases, this welding method did not receive industrial use.

An outstanding achievement of welding technology was the development at the IES named after E.O. Paton in collaboration with a number of industrial enterprises in 1949 of a fundamentally new type of welding, called electric slag welding. The use of electric slag welding has introduced fundamental changes in the technology of producing drums, boilers, heavy presses, shafts of large hydraulic turbines and other large-sized products. The development of welding is associated with the emergence of new sources of heat for melting metals. Concentrated electron flow in a vacuum, on the basis of which electron-beam welding appeared in the late 50s. It is used for welding refractory chemically active metals and alloys and special parts.

Selection of welding equipment

The main welding equipment is the welding arc power supply, which shall meet the following requirements:

- provide the arc current and arc voltage required for this welding process;

- have the necessary appearance of external characteristic to fulfill the condition of stable arc burning;

- have such dynamic parameters that normal arc excitation and minimum spray ratio can be ensured.

Process Description

Features of assembly and welding. After procurement operations, the structure parts are delivered to the assembly. An assembly is a process of sequentially connecting parts to each other in the order provided for by the process and drawing, for subsequent welding.

Depending on the design, type of production and process conditions for assembly, it can be carried out in various ways: by templates or the first product, by markings, by assembly holes in devices (universal, specialized and special). Assembly by marking is carried out without devices.

The highest assembly accuracy at minimum labor consumption can be ensured when using assembly and assembly welding equipment.

The main task of the assembly process is to determine the most advantageous sequence of assembly of individual parts, ensuring that the technical requirements for the manufacture of this product are met at the minimum cost of time, labor and auxiliary materials. Before assembly, the parts meet the drawing and process requirements visually.

Mating surfaces and adjacent areas of assembled parts with a width of at least 20 mm shall be thoroughly cleaned from rust, oil, dirt, scale and moisture in order to avoid the appearance of pores and other defects in the weld metal.

When assembling welded structures, the parts of the assembled welded assembly are arranged in such a way that they are located in the finished assembly. Assembly clearances shall be strictly in accordance with the drawing. Exceeding the edge of one of the butt joint elements above the other, if it is not provided and is not specified specifically in the drawing, it is allowed over the entire length of the weld not more than 0.2 of the element thickness (up to 4 mm) and 0.15 of the element thickness (over 4 mm, but not less than 1.5 mm).

Local edge excesses are monitored prior to welding.

During assembly, parts of welded structures are connected to each other by means of tacks, which are located in places of future welds. Tacks are made with coated electrodes or mechanized welding in protective gases. The cross-sectional area of the grips shall not exceed 2/3 of the cross-sectional area of the future seam and shall not exceed 2530 mm2. The length of each tack must be equal to 4-5 thicknesses of the parts to be connected, but not less than 15 mm and not more than 30 mm. The smaller the thickness of the parts to be welded, the smaller the distance between the tacks.

It is permitted to apply tacks outside the seams location for temporary attachment of assembly parts. Such tacks are removed after, and their locations are cleaned. It is rational to replace tacks with a continuous seam of a small section (process seam). Assembly tacks are made with the same welding materials as for welding of the whole structure.

The requirements for the quality of assembly tacks are set in the same way as for welding seams. Tacks and process seams are digested during welding of the main seam.

When welding longitudinal seams to insert the electrode into the seam and remove it from the seam outside the article, at the end of welding, the lead and lead bars must be welded to the edges. The shape of the strip preparation shall correspond to the preparation of the edges of the main seam.

Radiations

Ionizing radiation.

Ionizing radiation is used in industry for automatic control and control of technological operations, determination of wear of parts, quality of welds, metal structure, etc. Working with radioactive substances and sources of ionizing radiation poses a potential threat to the health and life of people who participate in their use.

During industrial flaw detection, different parts of the body of the flaw detector are at different distances from the radiation source and the hands are exposed to the most often increased radiation levels. With acute radiation burns of the hands, edema, bubbles and tissue deaths are observed, long-term non-healing radiation ulcers may also appear, at the site of the formation of which cancers are possible.

Hard X-rays and rays can be fatal without causing skin changes during external radiation.

Currently, the maximum permissible levels of ionizing radiation are determined by the RADIATION SAFETY STANDARDS (NRB99/2009). These norms define SDA as "the largest value of the individual equivalent dose for a calendar year, at which uniform exposure for 50 years cannot cause adverse changes in the state of health detected by modern methods."

BASIC SANITARY REGULATIONS FOR ENSURING RADIATION SAFETY (OSPORB99/2010) establish requirements for the protection of people from harmful radiation exposure under all conditions of exposure from sources of ionizing radiation, which are subject to the actions of NRB99/2009.

Ensuring safe working conditions during radiation flaw detection is directly related to the organization of protective measures, the main of which are: protection by time, distance and screens.

Protection by time (such a work schedule in which the dose received during the performance of work does not exceed the maximum permissible dose). In our case, "time protection" is supplemented by technological solutions: the use of reinforcing fluorescent screens (significantly reducing the transmission time), and the use of rational transmission schemes (the location of the device inside or outside the tank, pipe ).

Distance protection: we use devices with remote mechanical controls.

Screen protection: use weakening collimators of directional action.

The safety of working with ionizing radiation sources is also ensured by systematic dosimetric control. All defectoscopists working with sources are equipped with individual dosimeters (dl01) to control the radiation dose received by each employee.

On a quarterly basis, individual dosimeters are submitted for treatment to read the individual equivalent dose.

All defectoscopists are familiarized (under painting) with the instructions developed in the department: on safe work with sources of ionizing radiation; prevention of emergency situations and cases of theft of X-rays of devices during monitoring; personnel action in emergency situations with sources of ionizing radiation; radiation safety during radiographic inspection by flaw detector.

The means of collective protection are: radiation danger signs, light and sound alarms that weaken collimators.

The following are used as personal protective equipment: remote control panels, dosimetric devices, weakening collimators, lead screens.

Non-ionizing radiation.

In addition to aerosols and gases, a number of phenomena that are not eliminated by ventilation, but in combination with harmful substances that worsen working conditions, have an adverse effect on workers during installation work. This is the radiant energy of the welding arc, ultraviolet and infrared radiation, which causes burns to open parts of the body and sometimes (especially in summer) overheating of the body.

UV sources are: electric arc, autogenous welding, plasma cutting and spraying, laser installations, gas discharge lamps, radio tubes, mercury rectifiers, etc.

To protect against UV radiation, collective and individual methods and means are used: shielding radiation sources and workplaces; removal of maintenance personnel from UV radiation sources (distance protection - remote control); rational placement of jobs; special painting of premises; PPE and safety devices (pastes and ointments).

Infrared radiation is characterized by electromagnetic waves with a wavelength within 0.76... 420 μm. It is generated by any heated body whose temperature determines the intensity and spectrum of emitted electromagnetic energy. Heated bodies having a temperature above 100 ° C are sources of short-wave infrared radiation (0.7... 9 μm). With a decrease in the temperature of the heated body (50... 100 ° C) infrared radiation is characterized mainly by a long-wave spectrum.

The source of infrared radiation in production conditions are; open flame: molten and heated metal; materials: heated wall surfaces, equipment: artificial lighting sources, various types of welding, etc.

The large penetrating ability of short-wave radiation causes a direct impact on vital human organs (brain membranes, brain tissue, etc.), so there is a danger of its impact up to the "solar impact."

When exposed to the eyes, shortwave radiation is the greatest danger. A possible consequence is the appearance of infrared cataracts.

The main measures aimed at reducing the risk of exposure to infrared radiation are as follows: reducing the intensity of the source, protective shielding of the source or workplace, the use of PPE, medical and preventive measures.

Medical and preventive measures provide for the organization of a rational regime of work and rest and the organization of regular periodic medical examinations.

Resilience to emergencies

The main task in the event of an emergency is to preserve the life and health of workers at the enterprise.

Understand ability as stability of functioning of the enterprise it in the emergency situations (ES) to turn out products in the planned volume and the nomenclature (to perform the functions according to purpose), and in case of accident (damage) to restore production in minimum short terms.

Of particular importance now are the requirements for the sustainability of industrial production in peacetime emergency situations and the protection of conflict-related emergencies (terrorist acts). To reduce the likelihood of a terrorist act, the territory of the enterprise has a continuous stone and metal fence, along the top of which barbed wire is stretched. The number of access points to the territory of the enterprise has been reduced to the minimum required number and is guarded around the clock.

The access mode of the enterprise is organized using an electronic access system. Employee pass is a plastic card with a magnetic plate hidden in it, which electronically records the employee's data, his photo and the employee's access time to the enterprise. The aisles are equipped with electronic terminals and automatic turnstiles. When the employee applies a pass to the reader, his photo is displayed on the security monitor and, if the employee is allowed access to the enterprise at that time, the turnstile opens. Inspection of things is carried out by security officers. In our case, when the work is carried out in the field, conditions close to the conditions for protecting production from emergencies at the enterprise are created, and in especially troubled areas the base personnel and the surrounding area are provided with protection.

In the welding area, an emergency may occur in the event of a fire. It is possible to ignite cabinets of electrical equipment, engine oil and wooden containers, as well as the explosion of cylinders with liquefied gas. Fire safety requirements are regulated by GOST 12.1.00485 .

LVW used for degreasing of edges before assembly, methods of their storage and transportation must meet the requirements set out in the "Fire Safety Rules" approved by the Ministry (CP5 of 03.01.1986).

In case of an emergency, at the command of the site management, and if there are clear signs of danger to the health of the workers, at the command of the foreman or foreman, evacuation of the workers on the site is carried out.

The project provides for the location of a fire department with fire extinguishing equipment and fire extinguishers on the site.

The OHP1 fire extinguisher, the foam chemical fire extinguisher can work during 60... 65 seconds. They can extinguish burning gasoline on an area of ​ ​ 0.75 square meters. The OU2 fire extinguisher the carbon dioxide fire extinguisher used to suppression of the burning electric equipment.

Conclusions

The solutions used in the design ensure the safety of workers in automatic flux welding, namely:

1.The equipment is designed according to electrical safety requirements.

2. Protection of workers from the effect of welding arc radiation is provided by installation of boards and cockpits of the required height.

3. Protection of workers from harmful substances released during welding is provided by application of local exhaust ventilation.

4. The noise level is reduced to permissible limits by using noise silencers in hydraulic systems.

5. A fire shield with fire extinguishers is installed on the site.

6. The environmental friendliness of the project is ensured by the use of harmful substances in the ventilation system of filters-absorbers and the use of equipment that does not use working and cooling liquids.

7. The stability of the enterprise to emergency situations is ensured by the proper protection of the enterprise and strict compliance with the access regime.

Conclusion

In accordance with the technical requirements for the welded structure, the design drawing, the production program, work was carried out on the assembly and welding technology of the Coal Filter (adsorber) and the requirements for the reliability and service life of the structure, the main materials for welding were selected; appropriate welding materials, equipment necessary for welding the structure are selected to ensure equal strength of welds with the main material; welding modes are calculated, methods of producing a non-loose joint are selected, information on methods of quality control of welded joints is given.

To increase productivity and improve working conditions for workers, as well as improve the quality of welds, mechanized welding in the environment of protective gas was replaced by automatic welding under a flux layer. At the same time, material resources are saved due to the use of less qualified personnel and faster productivity.

During welding of shell housing with bottoms the following technical and economic parameters are provided:

- stability of production;

- quality of welds;

- reduction of material costs;

When introduced into production, the proposed welding technology provides cost-effectiveness of 868731rub.