Repair of scrap magnets
The company “Ecoforce” is equipped with specialized equipment, instruments, and technology to guarantee high-quality repairs of round electromagnetic lifting magnets of light and medium series with diameters up to 1200 mm and weight up to 1600 kg.
At “Ecoforce”, specialists work with excellent theoretical and practical training and accumulated experience in the repair of electromagnetic lifting magnets.
Our failure analysis shows that they are mainly due to the following reasons: insulation breakdown between turns and between sections of the excitation winding; electrical insulation breakdown between the winding and the housing components; interruption of electrical connections.
In over 90% of failures, the repair of electromagnetic lifting magnets involves dismantling the protective plate, the outer and inner pole, and removing the excitation winding.
Depending on the condition of the winding, repairs are carried out by recycling the winding conductor (partial repair) or, when recycling is not possible, by using a new conductor (complete repair).
In the complete repair of the excitation winding, we offer design modifications aimed at increasing the lifting force of the electromagnetic lifting magnet.
During repairs of the excitation winding of electromagnetic lifting magnets, we use modern electrical insulation materials with thermal resistance class F (155°C) and C (200°C).
The repair of the electromagnetic lifting magnet includes the following activities:
- Dismantling of the inner and outer pole pieces and the non-magnetic protective plate.
For electromagnetic lifting magnets with welded structures, the weld seam between the outer pole piece and the housing is machined on a vertical lathe, after which the electromagnetic lifting magnet is disassembled.
The pole pieces and the protective plate of electromagnetic lifting magnets assembled with bolted connections are dismantled after loosening the fastening elements.
- Removal
of the excitation winding and cleaning of the internal space..
In modern electromagnetic lifting magnets, the excitation windings (most often coreless) are encapsulated with compounds. To facilitate removal of the winding, in many cases the housing of the electromagnetic lifting magnet is heated in a furnace at a temperature of 190–200°C for a duration of 6–10 h. The internal surfaces of the housing and the protective plate are cleaned and painted.
- Repair
of the excitation winding.
Depending on the condition of the excitation winding, a partial or complete repair is performed.
Partial repair (restoration of: electrical connections; terminal box; part of the winding sections) is carried out after assessing the condition of the conductor and the electrical insulation materials. In this case, their reuse after recycling is possible.
In the case of a complete repair, from a technical and economic standpoint it is advisable for the excitation winding to be manufactured using modern materials.
Mandatory activities in a complete repair of the excitation winding include:
winding new winding sections; drying, impregnation, and subsequent drying of the sections; application of housing and inter-section insulation; testing the electrical characteristics of the sections; connecting the sections and testing the electrical characteristics of the winding.
- Sealing and gasketting of the internal space
The service life of the electromagnetic lifting magnet is directly dependent on the quality of the electrical insulation compound, the technology used for casting the excitation winding, and the degree of sealing of the internal space.
- Assembly
of the electromagnetic lifting magnet
After installation of the non-magnetic protective plate, the inner and outer pole pieces are connected to the housing by welding. To ensure high quality, we apply welding in a protective gas environment.
- Type testing of the electromagnetic lifting magnet.
