Oil Degradation
The function of lubricants is to remove contaminants, reduce friction, improve efficiency, minimize wear, and distribute the engine’s heat. Oil degradation can negatively affect your lubricating oil and hydraulic oil systems. Lubricant degradation occurs throughout the service life of the lubricants, depending on the oil type, the temperature, the operational conditions, and the environment. The baseline for change occurs when further deterioration leads to a level whereby the lubricant can no longer protect the system. When oil degrades, it changes composition and functional properties, and unwanted products are formed: acid compounds, soft contaminants (also called sludge/resins (dissolves in warm oil)), and varnish (deposit formation).
Oil conditions are to be monitored regularly to make sure the oil is used within its performance specification. Oil degradation products (or soft contaminants) are widespread problems in most industries. They are precursors of deposits, often referred to as varnish. Oxidation and thermal breakdown are among the causes of varnish formation, but the major reasons are micodieseling and static electric discharge. Varnish is known to cause issues in hydraulic and lube oil systems. Varnish products form a sticky layer on metal surfaces and will easily block fine tolerances. Hard particles of all sizes get caught in the sticky layer, creating a sandpaper-like grinding surface, which radically speeds up machine wear.
Oil degradation is seen more often today because oil systems are more stressed due to oil reservoirs being smaller, the oil temperature being higher, and service oil change intervals being prolonged. Varnish can be dissolved, insoluble, or cured, and its state is very dependent on the temperature and contact with air:
– Varnish is dissolved in its base fluid (for example, mineral base oil).
– Varnish will precipitate out immediately when it becomes insoluble (the portion above the saturation point at a given temperature).
– Varnish is cured and no longer solvable with its base fluid when in contact with air/oxygen or “baked” on hot surfaces (for example, lacquer on cylinder liners in diesel engines).
The fluid temperature has a huge impact on almost any given solubility. The “varnish generating spots” are usually the “hot spots,” while the “varnish deposit spots” are usually the “cold spots.”
Varnish has many consequences within your hydraulic oil, compressor oil, or lube oil system. Valve sticking causes loss of control, filter plugging, and restricted oil flow. The “sandpaper surface” increases component wear. Varnish causes ineffective cooling (poor heat transfer), increasing the oil temperature. The lacquer baked onto bearings causes poor flow, increased temperature, and vibrations. All of these lead to a loss in equipment availability, loss in revenue, frequent oil changes, and increased maintenance costs.
How can you identify oil degradation?
Top Six (6) Lubrication Degradation Modes
Oil Oxidation Products:
– Loss of antioxidants
– Producing varnish, sludge, and sediment
Thermal Degradation (Thermal Breakdown):
– Increase in temperature over 200°C
– Producing coke (carbon deposits)
Microdieseling:
– Entrained air – antifoaming property
– Producing varnish, carbon insoluble, soot, sludge, tars, coke, and resins
Electrostatic Spark Discharge:
– Increase in conductivity of the oil
– Producing varnish, sludge, or insoluble materials
Additive Depletion:
– Loss of additives
– Producing deposits
Contamination:
– Foreign particles present
– Producing various deposits
What causes accelerated oil degradation? Many causes can accelerate the oil degradation process. The key is to remove oil degradation products before they have the time to react further and form insoluble sludge and varnish deposits. An oil system free of varnish deposits has a longer oil life, increased oil performance, lower energy consumption, increased productivity and uptime, less maintenance and breakdown, maintained additive performance, maintained oil viscosity and acidity, and is environmentally friendly.
Resolve Varnish Challenges
What are the varnish removal methods?
1. Physical Filtration (including absorption and adsorption)
– Depth cellulose filters
– Electrostatic filters
– Balanced Charged Agglomeration (BCA)
2. Chemical Filtration: Cartridges with chemical bead compositions of different mixtures that are adjusted for increased efficiency on different oil brands and machine types.
3. Depth Filter Absorption/Adsorption with advanced varnish agglomeration: Systems that effectively precondition the oil so that all soft contaminants fall out of solution, agglomerate, and are removed by depth filter inserts with high dirt holding capacity.
Which of the three (3) different methods should you choose to remove the varnish?
This entirely depends on the efficiency of the system in different applications. Systems with oil operating temperatures around 40°C (100°F) and below can be treated with any of the above removal methods. Systems with oil operating temperatures of 40°C (104°F) and above can also be treated but are more difficult as the solubility and varnish ‘production’ increases. Another factor is runtime vs. downtime, which affects varnish removal. As the oil cools down and you continue running the filter, it will collect anything coming out of the solution.
Oil Degradation Solutions: CJC Oil Degradation Treatment
– The CJC Fine Filter and Filter Separator retain varnish if the oil temperature gets below 40°C (104°F).
– The CJC Varnish Removal Unit VRU (CJC VRU) is designed for the removal of varnish and soft contaminations – dissolved and in suspension (oil temperatures always +60°C (140°F)).
CJC Oil Degradation Solutions: CJC Varnish Removal Unit VRU 27/108
Varnish removal systems provide continuous kidney-loop filtration and circulation of the turbine oil in the reservoir. Varnish removal systems enable you to effectively maintain very low varnish content in your turbine lube oil, as measured by MPC (Membrane Patch Colimetry).
CJC Varnish Removal Unit VRU 27/108
CJC Varnish Removal Unit VRU 27/108
The CJC Varnish Removal Unit (VRU 27/108) has an unheard high efficiency in removing soft contaminants from oil (dissolved and suspended), even from hot operating natural gas and steam turbines. Oxidation and varnish are known to cause problems in many industries, resulting in costly production stops, turbine trips, loss of revenue, etc.
Varnish Removal Systems for Turbine Lubrication
Due to high operating temperatures, the oil in a gas turbine will suffer from an oxidation process which produces, among others, “varnish”-like substances in the oil system. If not removed, this will lead to the malfunctioning of the system. Adsorption filtration is a simple and cost-effective solution to remove varnish.
Function of CJC Varnish Removal Unit VRU 27/108
The CJC Varnish Removal Unit 27/108 is designed to remove dissolved and suspended soft contaminants by polar attraction in the optimized cellulose-based Varnish Removal inserts, VRi. The CJC Varnish Removal insert, VRi 27/27, is used in the CJC Varnish Removal Unit, which makes it possible to remove oil degradation products from oil in gas and steam turbines. The VRU contains 4 x VRi 27/27 Filter Inserts, specially designed for efficiently removing dissolved and suspended soft contaminants from turbine lube and hydraulic oils that operate at continuously high temperatures.
Varnish Removal Insert, VRi
It does this without any additional power, chemicals, or beads, which may harm the oil’s additive package. The warm system oil is drawn from the bottom of the tank to the VRU by its transfer pump. The oil is treated and filtered in the VRU before being returned to the system tank as varnish-free oil. The varnish-free oil will start cleaning all system components in contact with oil, ultimately resulting in a complete, varnish-free system. The varnish level in the oil will typically be cut in half within a few weeks of operating the VRU.
Benefits of CJC Filter Inserts
CJC Varnish Removal Insert VRi 27/27
The CJC filter inserts have a high dirt-holding capacity. The unique construction of the bonded discs creates a large filtration area, resulting in reduced ownership costs. The CJC filter inserts are a modular design, allowing them to fit any application and requirement. The specially designed CJC Varnish Removal inserts VRi, used in the CJC Varnish Removal Unit, make it possible to remove oil degradation products from oil in natural gas and steam turbines, up to 45,000 liters (11,900 gallons) that are dissolved and in suspension even from high-temperature operating turbines.
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- The CJC filter insert features a depth media of moulded cellulose with a high dirt-holding capacity. The CJC filter inserts are 100% natural cellulose fibres from sustainable resources; no plastic, no metal, no chemicals.
- Removal of Contaminants, 4-in-1:
- Particles: The lifetime of turbine lube oil and critical components has increased considerably.
- Oil Degradation Products: Avoid sticking valves, lacquering, and varnish on metal surfaces.
- Water: Reducing the risk of micro-pitting, oil degrading bacteria growth, sludge, etc.
- Acidity/TAN: Reducing oil aging and wear on equipment.
- OEM Requirements: C.C. Jensen’s experience and application knowledge ensure that CJC solutions meet OEMs’ oil cleanliness specifications.
All of these help to minimise further oil degradation. CJC oil filtration will maintain both oil and system cleanliness, leading to longer oil life, increased oil performance, lower energy consumption, increased productivity, and less maintenance.
The CJC VRi filter inserts can be used to maintain gas turbines, steam turbines, compressors, hydraulic systems, generators, and gearboxes. Remember to change your CJC Filter Inserts according to the pressure gauge or at least once a year in order to ensure clean and dry oil. For further information about the CJC Varnish Removal Unit VRU 27/107, visit C.C. Jensen’s website or contact Separator Spares & Equipment for pricing and delivery time period for a CJC VRU 27/108 varnish removal system. Let us help you resolve your varnish challenges.
Efficient and Easy to Use!
What are the benefits of a varnish-free oil system?
CJC VRi Varnish Removal Insert
A varnish-free oil system improves turbine performance and reduces maintenance issues. Here’s how:
– Better Reliability and Uptime: Turbines run more consistently without varnish buildup.
– Fewer Shutdowns: Prevents turbine trips and failure to start caused by varnish.
– Smooth Control: Keeps fuel and IGV valves from sticking, ensuring full control of the governor system.
– No Tank Cleaning or Flushing: Eliminates the need for regular deep cleaning.
– Longer Lifespan: Extends the life of both the lubricating oil and system components.
– Improved Cooling: Keeps the oil cooling system clear, preventing temperature spikes.
– Stable Varnish Levels: Maintains safe varnish levels (MPC < 15).
– Quick Varnish Reduction: Lowers varnish levels by over 50% within three hours (from VRU inlet to outlet).
– Easy maintenance: The CJC VRU can be serviced without shutting down the turbine.
Oil Degradation | The right solution for your application!
Oil degradation can have negative effects on your lubricating oil and hydraulic oil systems. Keeping the oil as cool as possible may increase lube oil life and reduce thermal breakdown. Do you need to slow down the degradation process in your oil reservoirs? We supply solutions for removing dissolved and suspended soft contaminants from oil in gas and steam turbine lube oil reservoirs. We can help significantly increase equipment uptime. The first step is to contact us for oil degradation and varnish removal case studies! Let us help you avoid varnish-related turbine trips, downtime, and expensive repairs.
We provide peace of mind and guard against unnecessary downtime!
To learn more about clean lubricating oil, visit our Clean Lubricating Oil will Maximize Equipment Lifespan blog.
To learn more about hydraulic oil cleaning, visit our Comprehensive Guide to Hydraulic Oil Cleaning blog.
To learn more about engine filtration, visit our Engine Filtration: Essential Fuel and Lube Oil Solutions for Peak Performance blog.