A customer in the Oil and Gas industry needed a new dust collector to replace their old one. The old collector was inefficient and creating workplace hazards. The customer needed a more efficient solution that would properly gather the dust created by their tumble blasters while reclaiming the shot for later use.
The Situation
This major supplier to the Oil and Gas industry needed to replace an aging dust collector installed on three tumble blasters, their surface preparation machines. A new dust collector was needed because the system was not sized properly. Further, it was pulling too much air in certain places and not enough in others. Their dust collector and ductwork were also just completely worn out. The customer had shot media falling on the floor due to holes in the duct. This was causing slip and fall hazards.
Tumble blasters use a process of tumbling parts within a housing that spins to expose all sides of a part. On the side of the housing, there are typically multiple wheels. They rotate at high speeds and sling abrasive shot media into the housing. This is how they clean or prep the outside edge of a part. The shot creates dust from the part and the blast media breaking down.
A dust collector is needed in the process to ensure the dust is removed and allows the reusable shot to flow through and back to the wheel. When done properly, this process saves the end-user a significant amount of money on replacement shot media. They also get a more desirable surface on their part.
The Evaluations
The company contacted Tri-State Industrial Contractors, a local contractor, to specify the best dust collection system for the project. They in turn brought in Scott Davis of Air Solutions, Inc., an independent manufacturers’ rep firm. They specialize in industrial ventilation solutions and represent Imperial Systems. When he arrived on site, he learned that they already had been quoted a 9,000 CFM Donaldson Torit replacement system.
Instead of taking that Donaldson Torit quote and offering a similar size dust collector, Scott reviewed the system to ensure that Air Solutions was providing the right equipment for the job. While reviewing the system requirements, it was determined that Donaldson’s quote did not include enough air for all the drops. This system required 11,000 CFM. When selecting and sizing a new dust collector, it is very important to give the system adjustability. There must be enough air to clean the dust from the shot, but not too much suction that reusable shot is pulled through the system to the dust collector.
The Solution
Air Solutions did the most thorough evaluation of the customer’s needs including replacement ductwork and a new dust collector. Education was provided for the customer regarding the blast machine dust collectors and included a review of several requirements for a successful blast filtration project:
- All drops should be balanced with air bleed-in fittings. This allows the end-user to reduce the air at the blast machine by bleeding air into the duct. This process maintains the duct velocity in the trunk line to ensure settling of dust does not occur.
- The conveying velocity in the duct needs to be high enough that the dust and spent shot do not settle in the duct. This is a significant safety concern. If conveying velocity is not maintained and materials do settle in the ducting, the ductwork could collapse or fall due to excessive weight endangering personnel and processes below.
- Energy savings are realized by using a VFD airflow controller. The VFD allows the dust collector to run at a consistent designed static pressure in the ductwork to maintain the same airflow when the filters load and the pressure drop increases through those filters. When the filters are new, the customer saves energy because the fan does not have to consume as much electricity to draw the required air volume.
Dust Collection Masters for Those Tumble Blasters
Ultimately, the customer selected Air Solutions and Imperial Systems to provide a CMAXX Dust & Fume Collector. The CMAXX is a perfect fit for multiple reasons. The absence of external hardware and the domed roof offers a leak-free design. These features combined with the lifetime warranty gave the customer the peace of mind to install the dust collector outside. Robust, heavy-duty construction also ensures a long life for the machine in an abrasive blast application.
The CM012 model was selected for this project. The CMAXX was sized for 11,000 CFM with an air-to-media ratio (AMR) of 2.62:1. An integral 40 HP, top-mounted fan was used to provide the design air volume at 12” w.g. static pressure. This dust collector was installed during the summer of 2018 and at publication has only required one filter change.
