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18 / November 2020 powderbulk.com PNEUMATIC POINTS TO PONDER Jack Hilbert, SME, and Julien Mathieu Morel, guest author, Hatch How pneumatic conveying and filtration equipment can affect one another In this issue, guest author Julien Mathieu Morel, bulk material han- dling engineer at Hatch, offers his perspective and recommendations on the interactions between a pneumatic conveying system and the downstream particulate filtration device. W hen we think about a pneumatic conveying system, we typically think about process pieces such as blowers, piping, and rotary air- locks, but one piece of equipment that's often left out is the type of filtration equipment at the end of the conveying line. Pneumatic conveying systems and filtration equipment are often put together with less thought or planning and more so with cost as the driving consideration. This can lead to a range of issues including insuffi- cient system performance, excess energy consumption, material damage, equipment damage, operational downtime, or limited flexibility for process or associated system changes. The selection of the filtration equipment depends on certain factors: The pneumatic conveying system type, the overall layout, and the material receiver type as well as the number of equipment pieces that need to have an extraction point. Here's a typical descrip- tion of the most common filtration equipment that's used in conjunc- tion with a pneumatic conveying system. Dust collector. Typically, a dust collector is a self-contained, free-standing unit used when sev- eral equipment pieces need to be dedusted at the same time or the location of the final filtration point needs to be located away from the particulate source point. Filter-receiver. A filter- receiver is basically a receiver unit into which a pneumatic conveying system directly discharges both material and air. The material dis- charges from the filter- receiver's bottom via an airlock while an integral dust collector section in the filter-receiver's upper portion is used to capture the fine particulates before the conveying system air is discharged downstream to atmo- sphere (in the case of a pressure system) or to the vacuum blower (in the case of a vacuum system). Bin vent. A bin vent is a dust collector without a hopper that's installed on a bin, silo, or hopper into which the pneumatic convey- ing system discharges both material and air. All these equipment types need to be considered with the same level of importance during the pneumatic conveying sys- tem design. In this article, design considerations of both pneumatic PBE conveying systems and filtration equipment will be looked at to show how one can affect the other. Design considerations As previously presented in other "Pneumatic Points to Ponder" columns, a pneumatic convey- ing system design needs to follow design considerations regarding the system type, conveying mode, velocity profile, pressure drop, air- to-cloth ratio, and the conveyed material's physical and chemical properties with respect to the filtra- tion equipment to ensure that the entire system will operate ade- quately. All these considerations and design decisions could have an impact on the filtration equip- ment's design and performance. The final filtration selection and its installation can lead to pneumatic conveying system performance issues if not implemented correctly. For this reason, each consideration is important and needs to be care- fully evaluated before selecting the filtration equipment. System type. The first consid- eration is the pneumatic conveying system type. Will you choose a pressure system or vacuum system? The mix of air and material will go through the filtration equipment in both systems. For this reason, the same design parameters that deal with the filtration equipment