Transformer Accessories
Oil Purifier for Transformer Insulating Oil Treatment
Oil Purifier for Transformer Insulating Oil Treatment
1. What Is an Oil Purifier?
An oil purifier, also widely known as oil filtration machine, is a specialized industrial equipment designed to clean and regenerate industrial oil liquids. For power transmission industry, the most commonly used type is transformer oil purifier, which targets insulating oil inside oil-immersed transformers, reactors, high-voltage switches and capacitors.
During long-term operation, transformer insulating oil gradually absorbs moisture, air, solid particle impurities. Under thermal stress and electric field, oil will oxidize, produce acid substances and sludge. These contaminants sharply reduce the dielectric strength of insulating oil, accelerate the aging of transformer internal paper insulation, and raise risks of partial discharge, internal breakdown and transformer failure.
The oil purifier removes water, dissolved gas, solid dirt and oxidation products from oil, restoring the insulation performance of aged oil. It supports new oil pretreatment before transformer filling, and on-site oil maintenance during transformer overhaul. Instead of directly replacing expensive transformer oil, regular purification greatly cuts operation costs and reduces waste.
2. Working Principle of Vacuum Oil Purifier
Vacuum oil purifier is the mainstream model for power industry. The purification process includes multiple continuous steps:
- Primary Filtration: Raw oil first passes coarse filters to trap large solid particles, protecting subsequent heating and vacuum components.
- Temperature Heating: Oil is heated to a stable working temperature to lower oil viscosity and accelerate separation of water and gas.
- Vacuum Separation: Oil enters high-vacuum separation chamber. Under negative pressure, dissolved water vaporizes and dissolved air escapes from oil. Water vapor and gas are extracted out by vacuum pump.
- Precision Filtration: Fine filter cartridges capture micro solid pollutants and oxidation sludge.
- Circulating Treatment: Oil can run through repeated cycles until all testing indicators meet IEC standard requirements.
Advanced two-stage vacuum oil purifiers adopt dual vacuum chambers to achieve deeper dehydration and degassing, suitable for high-voltage transformer projects of 220kV, 500kV and above.
3. Main Functions of Transformer Oil Purifier
- Dehydration: Remove free water and trace dissolved water in insulating oil. Water seriously lowers oil breakdown voltage.
- Degassing: Eliminate dissolved air and combustible gas inside oil, avoiding bubble discharge inside transformer.
- Solid Impurity Removal: Filter metal powder, fiber and oxidized sediment.
- Oil Regeneration (Optional): Equipped with adsorbent filter elements to reduce acid value, decolor severely aged oil.
On-Line Vacuum Oil Filling: Complete vacuum pumping and oil injection for transformers during maintenance.
4. Main Classifications of Oil Purifiers
4.1 By Vacuum Structure
- Single-stage vacuum oil purifier: Cost-effective, suitable for distribution transformers below 110kV, daily routine oil treatment.
- Two-stage vacuum oil purifier: Higher ultimate vacuum, deeper purification effect, designed for high voltage main transformers in substations and new energy power stations.
4.2 By Mobility
- Fixed oil purifier: Installed in workshop for centralized oil processing.
- Mobile / Portable oil purifier: Equipped with wheels, convenient for outdoor on-site transformer maintenance.
4.3 By Function Configuration
- Basic filtration type: Dehydration, degassing and particle removal.
- Oil regeneration type: Add adsorption system to treat heavily oxidized, acidified waste insulating oil.
5. Universal Technical Specification Reference Table
| Parameter Item | Standard Range | Remarks |
|---|---|---|
| Processing Flow Rate | 300 ~ 18000 L/H | Multiple models to match different project scale |
| Ultimate Vacuum | ≤5 Pa (Two-stage); ≤50 Pa (Single-stage) | Core index of purification capacity |
| Working Temperature | 40 ~ 70 ℃ | Adjustable constant temperature control |
| Filtration Precision | 1 ~ 5 μm | Multi-stage gradient filter system |
| Power Supply | 380V 3 Phase / Custom Voltage | Global power grid compatible |
| After-Treatment Breakdown Voltage | ≥70kV | Meet IEC standard for transformer insulating oil |
| Control Mode | Automatic / Manual Operation | Optional PLC intelligent control system |
| Compliance Standard | IEC 60422, GB/T 7595 | Insulating oil quality management standards |
6. Single-Stage vs Two-Stage Vacuum Oil Purifier
| Comparison Item | Single-Stage Vacuum Oil Purifier | Two-Stage Vacuum Oil Purifier |
|---|---|---|
| Vacuum Performance | Medium | Ultra-high deep vacuum |
| Water & Gas Removal Capacity | Conventional purification | Deep removal of trace moisture and gas |
| Applicable Transformer Voltage | ≤110kV distribution transformers | 220kV, 330kV, 500kV high voltage transformers |
| Equipment Cost | Economical | Higher investment |
| Working Scene | Workshop oil treatment, simple maintenance | Substation overhaul, wind & solar station projects |
7. Core Advantages of Oil Purifier
- Extend Transformer Service LifePurified insulating oil reduces insulation aging speed, effectively delaying equipment replacement cycle.
- Reduce Operating ExpenseReuse treated oil instead of purchasing brand-new insulating oil, save raw material cost and waste disposal expense.
- Improve Power Supply SafetyStable oil dielectric strength minimizes partial discharge and internal fault risks of oil immersed equipment.
- Flexible Mobile OperationPortable models support outdoor field service, no need to transport large volume transformer oil back to factory.
- Intelligent Stable OperationAutomatic temperature protection, overpressure and overload alarm functions prevent equipment failure.
Environment-Friendly SolutionReduce waste oil discharge, conform to industrial environmental protection requirements.
8. Typical Application Scenarios
- Urban & rural power grid oil immersed distribution transformers
- High voltage main transformers in power substations
- Wind farm and photovoltaic power station step-up transformers
- Oil immersed reactors, high voltage oil circuit breakers, capacitors
- Mining, steel, chemical industrial power supply transformers
Power engineering companies providing transformer maintenance service
9. Operation & Maintenance Recommendations
- Check filter pressure gauge regularly. Replace filter cartridges when pressure difference rises to warning value.
- Inspect vacuum pump oil level every week; replace vacuum pump oil periodically.
- Avoid running the machine without oil; prevent dry heating to protect heating elements.
- After long time storage, fully drain residual liquid inside pipelines before restarting.
Keep equipment ventilated; regularly clean dust on radiator and electrical cabinet.
10. Frequently Asked Questions
Q1: How long does purification treatment take?
A1: It depends on oil volume and pollution degree. Generally, full circulation 2~4 times can reach qualified insulating oil standard.
Q2: Can oil purifier fully restore seriously aged oil?
A2: Standard vacuum purifier removes water, gas and particles. For oil with very high acid value, regeneration type purifier with adsorbent is required.
Q3: Can the machine work continuously 24 hours?
A3: Qualified industrial oil purifier supports long-time continuous operation under normal working conditions.
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Contact Us
Contact: Tianjin Delda Trading Co., Ltd
WhatsApp: +86 13662056855
Tel:
E-mail: solomon20210701@tjxddq.com
Add: Unit‑101, Workshop 3, Bozhong Automobile Industrial Park, No.5 Xianghui Road, Intersection of Xianghui Road and Gaoying Road, Beizhakou Town, Jinnan District, Tianjin, China