Damages of burner pipes due to the working conditions and its repair welding

Repair welding represents the activity that restores the working capability of machine or construction caused by some damage due to working or environmental condition. Damages of burner pipes, part of the facility "Cold Rolling Mill" Steelwork in Smederevo, which appeared on welded joints during the manufacturing of the burner, and its repairing are presented in this paper. The damages occurred on welded joints along the weld as a result of the working conditions that burner was exposed to. Due to high temperatures that can reach up to 850 degrees C and "explosion" during gas burning, a crack may appear on the inner side of the burner. The base material of the burner pipes is stainless steel X12NiCrSi35-16. Repair welding is preceded by a series of operations, and one of them is the selection of an electrode. It turned out that inadequate selection of the electrode for repair welding had contributed to the occurrence of cracks on welded joints. Selecting a new electrode and examining its characteristics, as well as performing test welding of pipe that is still in exploitation, had confirmed the importance of proper selection of materials for repairing of burner pipes

Repair welding procedure and techno-economic analysis of burner pipe

The selection of the electrode for repair welding is one of the activities needed before repairing machine parts. In this case, damages that have occurred in a burner pipe welded joint during manufacture or previous repair welding have resulted in the need to replace the previously used electrodes with more suitable ones for the exploitation conditions to which the burner is subjected. For this purpose, 2 specimens welded with 2 different electrodes (Castolin and 6825 and PIVA 25/20 B) are cut from the pipes and tested. Micro- and macro-analyses of these specimens are performed, along with hardness testing. It is concluded that the Castolin 6825 electrode is better suited for burner pipe repair welding. Following this, the test repair welding of the burner pipe is performed. In addition to penetrant tests of the welded pipe, a short overview of the techno-economic analysis of the repaired pipe is given, including the ratio of repair price to the price of manufacturing a new burner

Repair welding procedure and techno-economic analysis of burner pipe

The selection of the electrode for repair welding is one of the activities needed before repairing machine parts. In this case, damages that have occurred in a burner pipe welded joint during manufacture or previous repair welding have resulted in the need to replace the previously used electrodes with more suitable ones for the exploitation conditions to which the burner is subjected. For this purpose, 2 specimens welded with 2 different electrodes (Castolin and 6825 and PIVA 25/20 B) are cut from the pipes and tested. Micro- and macro-analyses of these specimens are performed, along with hardness testing. It is concluded that the Castolin 6825 electrode is better suited for burner pipe repair welding. Following this, the test repair welding of the burner pipe is performed. In addition to penetrant tests of the welded pipe, a short overview of the techno-economic analysis of the repaired pipe is given, including the ratio of repair price to the price of manufacturing a new burner

The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors

The research presents an experiment with a model of an electronic generator for energy injection into the plasma of a fusion reactor. By recording a non-ionizing field in the vicinity of a fusion reactor, it was determined that this field has an extremely high growth rate. At the site of the maximum intensity of the field of non-ionizing radiation, commercial surge arresters with a flexible model of surge arresters were used for experimentation. It has been found that the commercial surge arresters have an efficiency of about 20%. For the efficiency of the flexible model, it was found to be slightly less than 40% (and to be achieved by the application of alpha particle radiation). Since neither of these efficiencies guarantee reliable operation of the gas-filled surge arrester, it was concluded that essential electronics in the vicinity of the fusion generator must be protected. However, since this protection can only be implemented in a fusion reactor, the fact remains that the environment of such a reactor is extremely contaminated with non-ionizing radiation. Commercial surge voltages are isolated for testing since the protection of electronic circuits from fast overvoltages is a critical point for the functioning of modern electronics

Influence of gamma radiation on measurement fast pulse voltages by Kerr electro-optic effect

In this paper, the possibility of measuring the electronic pulse from an electronic generator for plasma heating by electro-optical method is considered. The experiments are performed by applying the Kerr effect on an electronic generator model. Kerr effect shows very good characteristics for measuring nanosecond pulse rate. However, the results obtained show that these characteristics are significantly spoiled by gamma radiation in a dynamic state as well as by the absorbed dose of gamma radiation. When the simplicity of measuring with a capacitive probe is added to that, it can be concluded that the Kerr electro-optical effect is not recommended for measurement in fusion experiments

Comparison of Measurement Reliability of Nanosecond Rectangular Voltage Pulses by Kerr Effect and by High-Speed Voltage Probe

Recently, the idea of injecting energy with electromagnetic radiation in order to heat the plasma to achieve controlled fusion has been abandoned. This initially favored mechanism was rejected because it has been shown that after a certain temperature the plasma glows and acts as a mirror that reflects electromagnetic radiation. For that reason, today the energy is injected into the plasma by electrons. For this purpose, pulses from several electron beam generators, based on a Marx generator, are synchronously fired into the plasma. In addition to economic problems, the biggest problem of this method is the appearance of jitter, i.e., pulses with a width of about 5 ns are not simply added up but propagated in time due to the impossibility of synchronizing simultaneous triggering of the multiple electronic generators. In order to avoid this, the possibility of monitoring the pulses from an individual electron beam generator for the purpose of online synchronization is investigated in this paper. The voltage pulse monitoring of the electron beam generator was measured by instruments with the fastest response—the electro-optical Kerr effect and a fast capacitive probe. The obtained results showed that the electro-optical Kerr response is somewhat faster but much more complicated, so the use of fast capacitive probes is recommended for practice

Repair welding procedure and techno-economic analysis of burner pipe

The selection of the electrode for repair welding is one of the activities needed before repairing machine parts. In this case, damages that have occurred in a burner pipe welded joint during manufacture or previous repair welding have resulted in the need to replace the previously used electrodes with more suitable ones for the exploitation conditions to which the burner is subjected. For this purpose, 2 specimens welded with 2 different electrodes (Castolin and 6825 and PIVA 25/20 B) are cut from the pipes and tested. Micro- and macro-analyses of these specimens are performed, along with hardness testing. It is concluded that the Castolin 6825 electrode is better suited for burner pipe repair welding. Following this, the test repair welding of the burner pipe is performed. In addition to penetrant tests of the welded pipe, a short overview of the techno-economic analysis of the repaired pipe is given, including the ratio of repair price to the price of manufacturing a new burner