White Papers

Effect of varnish on the performance and stability of journal bearings

Abstract
This paper is dedicated to characterizing the steady-state and dynamic behavior of journal bearings with the provision for varnishing. Degraded base oils and additives cause varnish at high temperatures. Once the varnishing initiates, the oil flow is restricted due to the reduction in film thickness, which leads to an increase in the operating temperature and further accelerated varnishing. The effect of the varnish on the bearing performances is predicted by solving the Reynolds equation for the pressure distributions with the mass conservation algorithm coupled with the energy equation through the viscosity. The solution of the Reynolds equation with the perturbations of the displacement and the velocity is used to calculate the stiffness and damping coefficients and determine the dynamic behavior of the bearing. At a given eccentricity ratio, the maximum pressure and temperature with the varnish become considerably higher than those without the varnish due to the reduced film thickness. Results are presented for both single and double axially grooved journal bearings. Results show that the maximum pressure decreases when the varnish size extends circumferentially at a given varnish thickness, but the maximum temperature still remains relatively constant. For both single and double-grooved bearings, the critical speed decreases considerably, leading to the reduction of the stability of the system.

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Innovative Technology to Improve the Efficiency of Heat Transfer Systems

Discover how advanced technology is revolutionizing Heat Transfer Systems (HTS), also known as thermal fluid heating systems or hot oil systems. These systems are essential for industries requiring precise temperature control and high-temperature operations without high pressure.

The Journey To Fill4Life

This whitepaper will teach you how to increase the life of your Turbine and Compressor oils, perhaps indefinitely… Sacrificial antioxidants play a critical role in determining the life and performance of turbine oils. The vast majority of the time when these oils are changed.

Why Hydraulic Fluids Fail

The annual global demand for hydraulic oils is approaching 5 billion liters, approximately 10% of all lubricants sold. Hydraulic oils are used in a wide variety of applications; however most of these applications have one thing in common: more severe operating conditions are resulting in accelerated fluid failure.

One of the most important properties measured in operating hydraulic fluids is its cleanliness. Although measuring contamination is an important aspect, contaminants cause equipment failure but not necessarily fluid failure. This presentation will explore the various mechanisms causing hydraulic fluid degradation and suggest methods to detect and avoid premature fluid failure.

 

Innovative Solutions to Address Lube Varnish in Hydrogen Seals

There is a plethora of varnish mitigation technologies available for mitigating varnish in large-volume lube oil sumps. These technologies are commonly installed on turbine oil reservoirs. However, there are so many other applications where varnish and deposits create reliability concerns, such as hydraulic units, gearboxes, and compressors. Even wind turbines can have performance problems due to deposit formations.

 

 

 

Managing Rotating Equipment Lube Oils in the Ammonia & Nitric Acid Industry

Compressors are an important machinery asset in the production of fertilizers and are integral in their ammonia and nitric acid production lines. Reliable compressor performance is dependent upon having a high quality, well maintained lubricant. These compressor lubricants are placed under a lot of thermal stress and may be exposed to process gases, which can cause rapid fluid deterioration. These chemical changes in the lubricant manifest themselves into mechanical challenges in the compressor set, such as vibration, bearing temperature increases and valve sticking in hydraulically manipulated controls. This paper examines the nexus between these chemical changes in the fluid and mechanical impacts to the machinery. Furthermore, best-practice condition monitoring strategies and maintenance actions are suggested for integration into a fertilizer plant’s reliability program.

New Approach for Controlling Varnish in Lube and Hydraulic Systems

This whitepaper reveals that after treating the client’s in-service hydraulic oil with Solvancer™, clients witnessed noticeable and immediate improvements in clamp speed and cycle time. Furthermore, significantly less time was required during their next shutdown to facilitate a mold change-over.

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