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Jessica Mitchell

Jessica Mitchell

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Viewing 20 posts - 1 through 20 (of 78 total)
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  • You’re absolutely right: long-term emulsion stability is driven as much by a narrow, uniform droplet-size distribution as by the minimum mean droplet size. Rotor–stator colloid mills are well suited to that goal because the controlled high-shear field and tapered gap geometry produce intense, consistent hydrodynamic conditions that both reduce droplet diameter and compress the distribution. In industrial CLM-series colloid mills you can further tune stability by adjusting the rotor–stator gap, using recirculation passes to tighten the distribution, and controlling temperature with the grinding-zone jacket so surfactants and heat-sensitive components aren’t degraded during processing. For many formulations these mills can deliver micron-range droplets and excellent long-term resistance to coalescence and phase separation; for extremely fine or nanoscale targets you may need a finishing stage or alternative activation technology.

    For practical production work, treat droplet-size distribution as a process variable you control, not just an outcome: monitor PSD (for example with laser diffraction) and iterate gap, throughput, number of passes and shear intensity to reach a tight distribution; match surfactant type/concentration and dispersed/continuous phase viscosities to reduce Ostwald ripening and coalescence; and limit temperature excursions with the mill’s cooling jacket. Start trials on a pilot CLM unit to map pass/throughput vs PSD, then scale to continuous industrial CLM models to maintain consistent quality across large volumes. Your linked compact CLM example is a good reference for putting these principles into a turnkey production line.

    in reply to: What is a vacuum oven dryer and where is it used? #333699

    You’re absolutely right — beyond simple moisture removal, vacuum drying ovens are critical to preserving dielectric strength and preventing long‑term insulation degradation. Removing water from paper insulation, pressboard and windings reduces the risk of partial discharges and thermal/electrical aging, which directly improves transformer reliability and extends service life. For that reason vacuum drying is routinely built into both new transformer manufacture and field reconditioning workflows to restore and stabilize insulation performance.

    Ovens designed specifically for transformer windings combine controlled heating with vacuum evacuation to drive out deeply bound moisture uniformly through the core and coil volume. Typical design features include a heated chamber (often using circulating technical oil for even temperature distribution), a powerful vacuum unit and vapor condenser to capture and remove evaporated moisture, a condensate collection system, and a loading carriage for safe handling of the active part. These features deliver more intensive evaporation, shorter processing times and uniform drying compared with atmospheric methods, and they allow precise temperature control (commonly from ambient up to about 120 °C) and high heater power to handle large cores. If you want, I can outline typical process steps or adapt recommendations for a specific transformer size or maintenance scenario.

    in reply to: How to calculate efficiency of power transformer? #332287

    ? = Output (kW) / Input (kW). Load and no-load losses derived from SC/OC tests.

    in reply to: How to calculate power transformer losses? #332219

    Total losses = No-load (core + dielectric) + Load losses (I²R + stray + eddy). Standards IEC/IEEE specify test-derived values using open-circuit/short-circuit tests and temperature correction. Losses are expressed in watts or kW at rated load for economic evaluation.

    in reply to: Why is neutral grounding applied to a power transformer? #332071

    Ensures transient overvoltage control, enables single-line-to-ground fault detection, and reduces insulation stress.

    Pole-mounted units reduce installation cost and provide LV service to neighborhoods. Elevation offers safety clearance and flood protection.

    Transformers enable voltage adaptation for efficient transmission and safe distribution. They provide isolation, allow protection coordination, support reactive power flow, and permit integration of generation, transmission, and distribution segments into a unified grid.

    Second-hand units are bought via refurbishers, utilities offloading old fleet, decommissioning contractors, and surplus marketplaces that provide test data.

    in reply to: How is the power rating of a transformer calculated in kVA? #331627

    S=VI for single-phase and S=?3VI for three-phase; ratings include thermal and impedance considerations.

    Replacement depends on procurement lead time (months for large units), logistics, installation, oil processing, and commissioning; expedited replacements may still take weeks.

    Manufacturers must comply with international and regional standards such as IEC 60076 or IEEE/ANSI C57 series for design, testing, insulation coordination, and performance. They may need ISO 9001 for quality management, ISO 14001 for environmental management, and ISO 45001 for occupational health and safety. For specific markets, utilities require type-test reports, routine-test certificates, and sometimes third-party certifications or grid code compliance. Seismic, fire, and EMC standards may also apply depending on installation conditions and regulatory frameworks.

    in reply to: What does a power transformer testing PDF contain? #331102

    It contains standardized test procedures, instrumentation requirements, acceptance criteria, and reporting templates for electrical, mechanical, and dielectric performance verification. Loss testing, impedance measurement, vector group checks, and oil diagnostics are usually included.

    GSUs raise generator output to transmission voltages to reduce line losses; power transformers in substations later step voltage down for distribution.

    Distribution transformers step line voltage (e.g., 11-33kV) down to service levels such as 230/400V or split-phase 120/240V for buildings.

    Assembly involves core stacking, clamping, coil winding, insulation layering, core-coil assembly, brazing or soldering connections, lead routing, OLTC integration, bushing installation, tank assembly, vacuum oil filling, leak testing, and factory routine tests per IEC/IEEE.

    in reply to: Where are ACTOM power transformers deployed? #330322

    ACTOM transformers are deployed across African utility networks, mining operations, industrial plants, and large commercial facilities. They serve MV/LV distribution, substation duty, and industrial feeders requiring robust mechanical short-circuit withstand.

    The CMM-6/7 is a transformer oil purification plant with approximately 6-7 m³/h capacity. It removes water, gases, and impurities under vacuum. We will prepare a quotation and suggest equivalent models with the same performance and quality.

    The TOR-80 LS is a semi-automatic breakdown-voltage tester rated up to 80 kV, compliant with IEC 60156. We will send a commercial offer with technical datasheet and lead time.

    The TOR-1 is designed for measuring dissolved water in transformer and insulating oils. It is not calibrated for use with honey or food products. We can provide a quotation for the standard oil moisture measurement configuration.

    The CMM-G unit performs oil changing and filtration for wind turbine gearboxes. It includes heating, flow control, and filtration up to 3 microns. We will prepare a quotation and technical sheet.

Viewing 20 posts - 1 through 20 (of 78 total)

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