Rewinding and Reinsulation
The electrical equipment of many old power stations and Industries i.e. Generators, Motors, Auxiliary equipment etc. have reached their expected Life span or are about to reach their limit of useful life. These old, over-burdened electrical machines have started showing signs of ageing has resulted in frequent faults, breakdowns, reduced outputs and lower efficiencies. All this has resulted in deterioration of old equipment leading to critical situation for power companies.
It is in this crucial area of rehabilitation of old Electrical machines, that the Winding and Insulation Division of Yashmun offers specialized engineering know-how and services. Advance technology and availability of high quality rewinding and insulation materials have made it possible to reverse the ageing process of old electrical equipment.
Our team is backed by the world famous American Group, MagneTek National Electric Coil of U.S.A. MNEC have a track record of rewinding hydro and thermal generator sets, unparalleled in number and quality, anywhere in the world.
It is in this crucial area of rehabilitation of old Electrical machines, that the Winding and Insulation Division of Yashmun offers specialized engineering know-how and services. Advance technology and availability of high quality rewinding and insulation materials have made it possible to reverse the ageing process of old electrical equipment. Not only does it help to rehabilitate but it also upgrades the capacity of these machines, besides enhancing its life span.
The economical aspect of this vital service need not be emphasized. In today’s inflationary economic conditions, the capital cost of new electrical equipment has become prohibitive. In this context Yashmun specialised services assume greater importance. Yashmun’s team is backed by the world famous American Group, MagneTek National Electric Coil of U.S.A. MNEC have a track record of rewinding hydro and thermal generator sets, unparalleled in number and quality, anywhere in the world. They are responsible for almost 50% of all large generator rewinding done in the U.S.A. during the last 30 years. Customers can now tap Yashmun for this international experience and high technology and expertise in the rewinding field.
Already Tata Power Company have utilized coils from MNEC for all of their generators at Bhira, Bhivpuri, Khopoli, and Trombay power stations.
The Yashmun team is made up of highly skilled and experienced engineers hand picked from the “Tata Electric Cos”. They have extensive experience and knowledge in the fields of power generation, maintenance, major repairs and rehabilitation of electric machines.
Our team carries out all assignments under rigid conventional and unconventional conditions with strict quality control checks at every stage. e.g. They have rebuilt sector cores of 62.5MW thermal generators in a horizontal position , which is normally done in a vertical position, a unique achivement reflecting the expertise and capabilities of the team. Yashmun have total rebuilding capabilities for HV generators, motors and condensers.
Yashmun also undertakes overhauling / repairs and rewinding of power and distribution transformers and the rewinding and reinsulation of Slip Ring Induction Motors i.e wire or strip winding.
Special care is taken while rewinding the rotor winding by using a mica base insulation suitable to withstand temperatures upto 160°c. Windings are normally impregnated with a synthetic resin varnish that has a high insulation resistance and excellent resistance to moisture.
Cryogenic cleaning is a process in which particles of solid carbon dioxide are propelled at a high velocity to impact and clean a surface. Traditional cleaning methods like bead blasting and sand blasting clean through a chisseling action, much like using an ice pick often damaging the substrate. Cryogenic cleaning on the other hand might be compared to a spatula as it lifts the contaminant away.
Credibly reintermediate backend ideas for cross-platform models. Continually reintermediate integrated processes through technically sound intellectual capital. Holistically foster superior methodologies without market-driven best practices.
REPAIR OF ONE SWLP MOTOR (P-2611-B) OF BPA AND ONE CONDENSATE PUMP-C MOTOR OF BPB PLATFORM” against Tender No. ONGC/S/OMG/ELC/ B&S/HT-MC/04/2007 dated 03.10.2007
Overhauling of 4 Nos. of MIP Motors of SHW Platform. TENDER No. ONGC/OMG/S/ELC/ MIP/SHW/06/2007 dated 25.05.2007
OVERHAULING & REPAIR OF 05 Nos. 6.6 KV MOTORS: MK-102A/B (850KW EACH) OF LPG-1 & MP-204 A/B/C (1350 KW EACH) OF OBPH, ONGC, URAN PLANT against Tender No. UP/11C07027.
Overhauling and Repair of HT motors at EPRU plant and LPG-CSU area, ONGC, Uran Plant, Uran. Ref: TENDER No.UP15C09013.
OVERHAULING 1- EMERGENCY GENERATOR OF SA, 2-BOOSTER MOTORS & 1-SWLP MOTOR OF ICW AND REWINDING OF 1 BOOSTER MOTOR OF WIS against TENDER No. MR/ES/MH/OH & REPAIR OF HT-MC/EG-BP-SWLP/2006 DATED 06.02.2007.
Repairs of 280 KW MIP-1160 Motor of Sagar Laxmi Platform.
Neelam & Heera Platform: Two years contract for Repairs and overhauling of various HT motors.
Repairing and overhauling of 3 Nos. PMG at SLQ platform.
Repairs and overhauling of 3 Booster SHW & SWLP of WIN platform.
Overhauling of 3 SWLP motors of SHW Platform.
Overhauling of 1.2 MW Alternator at SCA Platform.
Hard Bearing Horizontal Dynamic balancing Machine Model KH-3K with.
Maximum length accommodate between bearing center 4000 mm.
Maximum Dia. 2500 mm.
Balancing speed up to 800 RPM.
Microprocessor based Precision Electronics type MP-102
A stirrer located in the secondary cooling zone creates an equiaxed structure in the liquid pool. The width of the equiaxed zone mainly depends on the width of the pool at the structure is desired, the width of the pool at the stirring level. So, if a large equiaxed structure is desired, the S. Stirrer should be located as high as possible along the strand sometimes just below the mould.
The stirrers are designed in order to provide a rotative or a linear stirring movement, rotative stirrers are more suitable for small sizes, linear stirrers are more suitable for big sizes.FMS applied for casting of medium carbon steels, low-alloyed steels and stainless steels.
Design Technology of FMS
We distinguish between rotative and linear stirrers. Both are acting according to the principle of an electrical asynchronous AC- motor.
A rotative stirrer acts like the stator of an electrical AC motor. It is fed by a three phases or sometimes two-phase electrical power supply and creates a rotating magnetic field within its pole gap. This rotating magnetic field induces a torque in the liquid steel of the billet or bloom passing through the stirrer. The liquid steel consequently acts as the rotor of an AC motor and rotates around the axis of the cast product in a plane perpendicular to the casting direction.
A linear stirrer can be understood as the transformation of cylindrical inductor, which has been cut open on one side and unrolled to a flat size. One obtains a stator creating a traveling magnetic field. This traveling magnetic field induces a force in the liquid steel which points in the liquid steel which points in the traveling direction.
Choice of rotative or linear stirrers
There is a basic difference between rotative and linear stirrers: The rotative stirrer induces axial-symmetrical forces creating a torque over the whole section of the liquid pool whatever the size of the liquid pool is and even if the strand is not centered inside the stirrer. It follows that all the forces induced within the whole section of the liquid pool and consequently the full power induced inside the liquid pool contribute to the rotation of the liquid steel.
Performance of stirrers
The performance of a stirrer is given by the effective stirring force acting on the luquid steel and by the effective stirring power induced inside the liquid steel. Both have to be above a minimum value in order to produce the required metallurgical improvements. The performance of a stirrer are the magnetic flux produced by the stirrer and the frequency of the electrical power feeding. Increase of the magnetic flux always increase of the magnetic flux always increase the performance.
Design parameters of FMS
The stirrer surrounds the copper mold and induces a rotating magnetic field since the magnetic field must cross the copper walls, the stirrer is operated at low frequency 2 to 10 Hz depending on the mold size and the copper thickness) All pieces between the copper mold and the stirrer inner surface must be made with non-magnetic stainless steel.