How Intelligent Controls can Boost Profitability and Sustainability

In today’s competitive economy a company must consider every competitive advantage. One area that many companies overlook is in regard to the performance of their air filtration devices. Historically, industries purchased a collector for a given task and did not have options for an intelligent system. However, with the rapid advancements of technology, it is now possible to add intelligent controls to an existing dust collector and see the following results: 

• Significant reduction in energy consumption, in excess of 50% reduction (see the case studies outlined in this article). 
• Improved performance. 
• Increased capacity. 
• Improved filter life. 
• Reduced fan noise. 
• Combining multiple collectors on one main controller. 
• Provide an easy-to-read dashboard to track and record data. 

These improvements have a positive impact to a company’s sustainability goals and increase exponentially with larger collection systems.  

An intelligent control system utilizes a main control box that connects with every aspect of the facility as it relates to the collector. For example, in any given facility, the actual percent of assets that are operational at any given time is between 50%-to-70%. This includes time for setup/teardown, maintenance, missing operator, breaks or shift change and many more reasons. Therefore, an intelligent system will only generate the necessary suction to accommodate the operating assets and therefore modulate the fan speed accordingly.  

In many cases, when a system truly functions on demand, additional capacity is released within the existing system. In addition, when a collection system operates more efficiently, the velocity of the air across the filter media is decreased, hence allowing for the filters to clean more completely and in turn, significantly increase filter life. While monitoring the filters, the control system only cleans the filters when it is truly necessary and saves compressed air.  When the fan is slowed down due to demand, the noise of the fan will decrease as well. 

Many companies claim to offer controls, VFD’s and automatic gates, but if all a control system accomplished was to open and close gates, it would not be a truly intelligent system. The control system needs to monitor duct pressure and velocity to ensure that the proper velocity is maintained to prevent particulate from falling out within the duct. An intelligent system will know when and where to open assist gates to ensure proper duct pressure and velocity.  Be cautious of installing a control system without a thorough evaluation of the duct sizing. In most cases, some ducts will need to be adjusted in diameter to provide the most efficient solution. This needs to be accomplished by a knowledgeable duct sizing expert. 

An intelligent system uses a variety of sensors to determine which workstation gate needs to be opened. These sensors options include: current sensing, pneumatic sensing, proximity switches, motions sensors, mat sensors and even a simple timer. An intelligent system does not rely on the operator to open and close the gates. In addition, delays can be added to a gate to allow for the system to fully evacuate the asset for seconds or minutes after the process is complete. In the event there are insufficient assets functioning, a truly intelligent control system will open assist gates to ensure the proper velocity and pressure is maintained with no human intervention. 

All of this data is fed back to a PLC dashboard that can be monitored from a workstation or a mobile device. The information gathered includes: fan speed, duct velocity, duct pressure, filter pressure, broken filter warning, energy saved, compressed air used, gate open tracking, system uptime, bin full warning, explosion vent fault, spark detection warning, rotary airlock status and more.  Additional items can be added for the control system to monitor and provide reports, as well as historical analysis.  

In addition to the financial benefits of an intelligent system, (reduced energy consumption, reduced compressed air usage, increased filter life, defined maintenance schedules) an intelligent system aids companies in achieving their sustainability goals. Each of these benefits has a direct correlation to a reduction in CO2 emissions, clean air, reduced energy consumption, industrial innovation and responsible usage of natural resources. 

Case Study 1

The first case study is of a musical instrument manufacturer with four dust collectors totaling 700 hp. The facility had more than 270 workstations with only 180 operational at the same time on average, with a maximum of 230 stations. The dust collected was wood dust which is explosive. Dust was escaping their current collector at the source. Therefore, people were employed to just sweep the floors. The explosive dust was settling on top and inside the ducts. 

The objectives requested from the customer were to eliminate explosive dust from settling and improve the performance of the collector at the dust source. The customer did not want to add any additional dust collectors. An additional desire was to reduce energy consumption and carbon emissions. After an engineering study, these objectives were agreed to and an estimated 1,075,000 kWh of energy savings was forecasted. The study showing energy savings secured an energy grant of $133,000. 

The result of installing an intelligent control system with servo driven gates, workstation sensors, velocity sensors in the duct and a sweep function to overcome any intermittent fallout exceeded the customer’s expectations. The performance of the existing system improved significantly, no longer requiring personnel to sweep the floor. The noise of the collector was reduced significantly and the collector’s capacity increased. The actual energy savings exceeded 1,400,000 kWh (40% higher than projected) resulting in an increase of the energy grant to $161,000. The energy bill decreased by $235,200 annually and eliminated approximately 1,750 tons of CO2. The return on the investment was 15 months. 

Case Study 2   

The second case study is of a metal processing facility with polishing, grinding and shot blasting equipment. The shop operated three shifts a day, five days a week.  The shop has one dust collector at 125 hp and two additional collectors 80 hp each.  The shop consists of 12 drops of varying size. The dust being collected is nonexplosive metal dust.  

By adding an intelligent ventilation control system, servo driven gates and modifying the ducting, the customer was able to eliminate both 80 hp collectors. Each of the 80 hp collectors cost nearly $25,000 annually in electrical, filters, compressed air and maintenance. The electrical savings alone on the two collectors were $50,000 annually. When adding in the natural gas savings from make-up air, the total amount saved annually increases to $72,396. 

The addition of the intelligent ventilation control system reduced the electrical usage of the remaining 125 hp collector by an additional $28,000 annually. With the confirmed energy savings, the customer qualified for a $52,845 grant from the local energy company. Combining the total savings and incentives, the company received a ROI of just over two years.  Despite the elimination of two dust collectors, the current 125 hp dust collector still has approximately 10% added capacity available and improved performance at the drops. 

In summary, dust collectors by nature are not efficient.  However, with new technology, even old dust collectors can become more efficient. The larger the collector the greater the opportunity for improved efficiency and cost savings. 

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