Maintain secondary equipment via IIoT
An area of strong potential for IIoT is secondary equipment – devices essential for plant operation, but that do not directly generate revenue. These assets are good IIoT candidates for two reasons: They’re typically not connected to a plant’s existing control network; and maintenance teams – often challenged with labor or experience gaps – may be more focused on the production line.
Dust and fume collectors fall into this category (see Figure 1). While most facilities need to filter and ventilate various air streams, dust collection equipment often functions in the background and may compete for attention. However, issues such as clogged filters or worn valves can impact efficiency and could escalate into equipment failure without timely intervention.
In a recent independent survey by Plant Engineering magazine, sponsored by Donaldson Co., 38% of plant engineers said when their dust collector fails, their operation has to shut down. However, nearly half admitted the equipment hadn’t been evaluated in the past three years – or they were unsure when the last evaluation had been.
Real-world case studies
The benefits of monitoring nonproduction equipment with connectivity are becoming evident. In late 2018, Donaldson Co. introduced technology that monitors certain aspects of dust and fume collectors remotely and is launching a subscription service that provides this capability.
Using cloud connectivity, the connected solution gathers sensor data from operating equipment, applies filtration analytics and sends meaningful information back to the owner via a web-based dashboard, email alerts and weekly status reports (see Figure 2).
Between pilot- and early-adopter customers, more than nine facilities have used the solution, representing a range of industries from grain milling to metal fabrication. Multiple early users have reported positive results in three main categories:
- Reduced downtime for dust collection equipment
- Lower maintenance costs, including filter replacement costs
- Better management of dust-related risks and tasks.
Operations with multiple dust collectors have experienced the greatest benefits, but even smaller manufacturers have reduced the total costs of owning and maintaining this essential equipment. Here are two examples:
Feed processor. An animal feed processor in Minnesota generates high volumes of dust as it grinds and mixes grain with additives. The dust’s sticky properties posed a challenge for the dust collection equipment. During humid seasons, the material congealed and plugged the collector hopper, causing the particulate to back up in the dust collector.
A standard pressure gauge on the equipment measures differential pressure across the filters but is not designed to detect a hopper issue. So, the first sign of trouble was dust backing up into plant air. Maintenance crews had to shut down the collector, remove a large dust accumulation from the hopper and clean dirty surfaces throughout the plant. This unplanned maintenance took two hours per incident and, during one peak month, racked up 14 hours in additional plant cleaning time and costs.
For good reason, the plant manager was receptive to connected technology. Donaldson customized the IIoT installation for this facility by placing a sensor at the lowest point in the hopper. Now, that sensor detects early signs of plugging (see Figure 3).
The system alerts the maintenance manager through the dashboard and email alerts on his smartphone. Personnel can quickly remedy the issue before it escalates. Early detection reduced the corrective action to just 15 minutes and prevents dust backup into plant air.
In this example, a relatively simple improvement – earlier alerts – was a game-changer for the maintenance team. The cost of the IIoT installation was recouped in the first incident and has continued saving many hours of costly labor time each month.
Metal fabricator. In the metal fabrication industry, dust and fume control is important not only for hazard control, but also because airborne particulates can damage adjacent, expensive machinery such as laser cutters. When dust collection is interrupted for unplanned maintenance, production shuts down.
Unfortunately, this was a frequent occurrence at a metal fabrication shop in the Midwest. The plant had a cartridge-style dust collector with a self-cleaning feature designed to clean the filters with pulses of compressed air. However, the filters were prematurely plugging anyway. Elements designed to last one year under the plant’s demands were clogged and required changing in just six weeks, triggering additional downtime and filter replacement costs. The standard differential pressure gauge on the collector indicated the filters were quickly fouling, but could not pinpoint a cause.
Donaldson installed its IIoT technology, including a sensor on the compressed air lines entering the dust collector, and then the company technicians reviewed the data. For the first time, the cause of filter wear became apparent: There was inadequate compressed air pressure to clean the filters during times of high dust-loading. Although the problem was intermittent, it damaged filters enough that a normal pulse could not effectively regenerate them.
The key IIoT benefit in this example was not just a sensor in a new location. It was the capability of tracking and viewing compressed air pressure over time. Pressure changes are a valuable clue in isolating equipment problems. With this new information, the plant manager was able to make adjustments in the compressed air system that helped restore expected filter life.
ROI: Filter life is extended from six weeks to approximately one year, reducing production downtime and filter replacement costs.
Added benefit: Efficient use of time
Even when filters last a normal life span, changing them can be disruptive for many plants. If filters reach terminal pressure drop before the replacement is on hand, the wait can mean a day or more of unplanned downtime. But with sensors and an Internet connection, maintenance personnel can track differential pressure and anticipate a filter change in advance. The change-out can then be scheduled during planned downtime.
Not reported in these scenarios was the time maintenance supervisors saved by not having to monitor the dust collectors manually. Walking around with a clipboard and visually observing equipment is inconvenient and not as reliable. With a connected solution, detailed equipment status is accessible almost anywhere, which curbs time and travel costs. This is especially valuable for managers in charge of multiple dust collectors across many locations.
Early experience with connected dust collectors suggests that secondary equipment management is a promising application of IIoT. So far, the solution from Donaldson has supported filter life, helped improve production uptime and contributed to reduced labor costs. Plants in a wide range of industries have seen a drop in total cost of equipment ownership and time freed up for personnel to focus on higher-value production tasks.
Connectivity holds significant promise. Machines typically getting less attention, like industrial dust collectors, may be the best place to start.