Machinery Configuration: Quick Wins that Optimize Machine Performance

The landscape of manufacturing and industrial processes is constantly changing. Historically, titans of industry capitalized on large, cumbersome, overbuilt, sluggish equipment that had to be continuously maintained by a labor force that was paid an incredibly low wage. Modern industry is stressed to operate in a leaner landscape with fewer workers, purpose-built equipment and margins that, in many cases, are razor thin. This leads to improvement activities that get more and more out of less and less: more product and profit out of fewer people and with fewer failures or disruptions to business. In order to do this, practices and equipment both have to evolve to maintain pace with demands.

Fewer items are more scrutinized than the facility's physical assets; we have to make sure they perform how they are supposed to, when they are supposed to, and for however long they are supposed to. For this to happen, many factors have to be balanced, and often the equipment may not be capable of performing to this level in its current state. A higher state of configuration must be achieved - an optimum state that allows maintenance, operations and reliability to perform all necessary checks on the equipment without interrupting its service, all while maintaining or improving the inherent reliability of the piece of equipment.

Changing the configuration of assets or modifying them to improve performance is not a task that should be taken on lightly. To best modify the equipment for performance, we would first have to define how we want the equipment to improve. You can define optimized performance in many areas, and depending on your organizational goals, the changes to the equipment would have to follow suit. What follows are some of the most common reasons for modifying equipment to increase performance.

Increased Energy Efficiency

You can save money and improve performance by focusing on how much energy the equipment consumes. This energy can be electricity, diesel, gas, etc.; as such, we have a level of control in optimizing energy consumption compared to work produced. If we are focusing just on the lubrication realm of control, there are a few ways we can improve energy efficiency.

Lubricant selection is the first step in this process. We need to carefully and deliberately pick which lubricant to use based on the equipment’s needs and environment. A lubricant slightly too thick, too thin or without an appropriate additive package can translate into huge frictional losses, wear and temperature increases. Factors include the viscosity of the lubricant at operating temperature when compared to the required viscosity of the component; NLGI grade of greases to help minimize churning losses; viscosity index of the lubricant to maintain suitable film size at all in-service temperatures; friction modifier additive packages to minimize losses during start-up conditions. Lubricant selection can be a challenge for some equipment subjected to frequent operational changes and wide changing environmental conditions such as temperature swings.

In addition to selecting the proper lubricant, we must also ensure that we are operating the machine at the appropriate lubricant level. This is most critical in splash-lubricated or bath-lubricated machines, and doesn't just apply to under-lubrication. An excessive amount of lubricant inside the housing can create a condition of parasitic drag that will greatly increase the workload of the driving component, leading to increased heat and energy consumption.

Machines are designed to move through the lubricant at a certain level; variations in that level can impact the lubricant film being generated. We have to be able to splash or lift the appropriate volume at operating speeds. This is true for grease-lubricated components as well. It is common to see greased bearing overfilled with grease purging out of the seal. This puts a drag on the system and should be avoided.

Keeping lubricant volumes at the right level is just as much about inspection as it is application methods. We need to be able to add lubricants slowly so as not to bog down the system. This is most critical in greasing and ties to the previously mentioned condition of housings being over filled. Grease should be added slowly while the machine is in motion. This helps distribute the fresh grease while pushing the old grease out of the way. If grease is added quickly, the component operates in an over-pressured condition, leading to increased energy consumption. With oils, we must maintain the proper oil level in all environments, so being able to top-up or purge based upon any fluctuations is important.

Equipment Life Extension

One way to impact total life cycle cost is to keep equipment running at an acceptable level for longer. If we can reduce the failure rate, we can expect the machine to be able to perform longer with fewer issues. This is very much the root of proactive maintenance. To make this happen, we have to focus on the root cause of equipment failure. Oftentimes, contamination is one of the leading causes of equipment failure, and this serves as one of the most common places to start in terms of equipment configuration to enhance reliability.

Contamination control has two sides: exclusion and removal. Excluding contaminants means keeping them out before they can impact the equipment; removal is getting them out once they find their way in. Ideally, the asset will be modified to assist in both of these areas, and our maintenance practices will be changed to help maintain the cleanliness that the machine requires. It is much cheaper to exclude contaminants than to remove them once they get in.

To exclude contaminants, we tend to focus on all the areas of the machine that could possibly ingest contaminants. The most common culprits are shaft seals, breather ports and fill ports. All of these can be upgraded to some degree to lessen the risk of contamination. Seals can be better selected for compatibility with fluid, temperature and even aggressiveness of contaminants, such as utilizing a labyrinth-style seal.

Breathers have long been employed, and it is very common to find desiccant breathers on many pieces of equipment and even lubricants in storage. These are a great solution for minimizing incoming particles and reducing moisture ingression. A good desiccant breather will dehumidify incoming air and dry the headspace inside the equipment. These should be employed anywhere there are large temperature swings and with equipment that may be at risk of water contamination.

Quick-connects allow the lubricant to be added, drained, and even recirculated within the system without opening it up to the environment. The goal should be to get the machine in a hermetic state where all lubrication, inspections and standard operational checks can be done without exposing the inside of the equipment to the atmosphere. Each time the equipment is opened, it is an opportunity for contamination and the introduction of a failure mode.

Removing contaminants has to complement any exclusion activities that are underway. Lubricants and equipment can be contaminated easily and quickly. The biggest tool in the removal arsenal is filtration. Filters can be added to equipment permanently (portable methods exist for more periodic decontamination). There is a vast array of options regarding filters, including filter types, locations, ratings, materials, etc. Each of these criteria must be scrutinized to match the optimum filter to our application.

While a particle filter is the most common form of contaminant removal, it is far from the only one. Systems that focus on removing other problems such as water, heat and varnish are also readily available and, in many cases, relatively easy to connect to equipment for use. Vacuum dehydrators, ion-exchange resin skids and heat exchanger packages can be customized and purposefully built to match your equipment's exact conditions. This more targeted approach yields longer life not only for the equipment but for the lubricant itself. This means fewer failures and fewer oil changes.