Machinery Lubrication

52 Reliable Plant | www . reliableplant.com Machinery Lubrication | www . machinerylubrication.com 2025 Annual CONTAMINATION CONTROL approach. Dissolved water is the hardest to remove and likely requires vacuum dehydration or similar, more aggressive removal strategies. Heat Heat is the catalyst that increases the rate of oxidation and other chemical degradation processes within the oil. Often cited is the Arrhenius rate rule, which says that chemical reactions double every 10°C increase in temperature. is applied to oxidation means the rate of oxidation doubles with the same step in temperature, so the oil life is effectively cut in half. We want lubricants to operate as cool as possible. In most cases, heat is difficult to avoid and is present due to the nature of the operation (friction) or because of the environment (ambient heat, close proximity to ovens, etc.). In either case, we try to guard the equipment against excessive heat. is may include shading for equipment exposed to direct sunlight or heat shields for equipment installed close to hot areas of the process. Controlling heat is largely a task for heat exchangers and housekeeping. You want to ensure the equipment is kept clean to promote the dissipation of heat from the case of the equipment to the environment. Heat exchangers are used when passive cooling isn't adequate. ese devices may utilize fans or cooling fluids to promote faster removal of heat from the systems. For smaller pieces of equipment where these may not be economi- cally feasible, we should ensure we are using the correct viscosity and fluid volume so as not to unnecessarily create more drag and fluid friction that would compound the issue. Air Of course, for oxidation to occur, there must be oxygen present. e air that exists within the system is the source of most of this oxygen. Our equipment typically operates at atmospheric pressure, especially splash-lubricated machines and most fluid reservoirs. At these conditions, oil holds air in a dissolved state, up to 10% by volume. As oil experiences turbulence and movement through a system, bubbles can form and start to suspend through the fluid volume. is is entrained air and represents one of the areas of most concern with air contamination. Suction lea k s, turbulent reser voir conditions, and impaired surface tension of the oil are all mechanisms that can lead to entrained air. Once these bubbles are in the system, they hang out in the oil volume and increase the area of the oil in contact with air. is further promotes oxidation and the byproducts mentioned earlier. To control this, we need to ensure the oil stays healthy, which in turn ensures the oil's air release properties remain intact. We want the air to rapidly separate from the oil. To further aid in this, we want reservoirs to be as calm as possible, so the addition of baffles, diffusers, and other devices to slow down the movement of the oil can make a huge impact on the amount of entrained air that is allowed to move throughout the system. Metal Catalysts Like microscopic spark plugs, the metal particles suspended in the oil greatly impact the rate of oxidation. ese particles can react with the air in the system, creating more reactive oxygen species that then attack the oil. ey can also react with hydroperoxides in the oil, making more reactive molecules that increase the rate of oxidation and acid formation. Also, the metal surfaces provide a site for oxidation reactions to occur, allowing oxidation to occur more rapidly. Most of our equipment is comprised of metal, so its presence is not uncommon. However, it is the small wear particles that can cause us great concern. ese particles are released from the machine surfaces during operation and then allowed to move throughout the system, coming into contact with more of the lubricant. As their concentration grows, the more surface area is present through the system, which increases the rate of oxidation. To reduce these impacts, we must ensure that our equipment is mechanically sound and operating well. is includes maintenance activities such as alignment, balancing, and solid mounting to ensure that the equipment isn't unnecessarily producing wear. Correct viscosity and additive packages to minimize wear are crucial from a lubrication aspect. We pair this with proper filtration to remove these fine particles and other wear-producing particles, such as dirt, to minimize the wear- particle population. Keeping the metal particles low helps slow down the oxidative process. While you may not have the greatest opinion on the band or the song, it doesn't mean that there aren't lessons to learn here. Keep in mind that WHAM is largely controllable, and if we focus on it, we can greatly increase the life of our lubricants. Much like the song says, "I'm not planning on going solo." Get your team involved in these improvements, as everyone involved in the lubrication program has a role to play in keeping these contaminants out of the equipment. ML " While you may not have the greatest opinion on the band or the song, it doesn't mean that there aren't lessons to learn here. Keep in mind that WHAM is largely controllable, and if we focus on it, we can greatly increase the life of our lubricants. "

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