Issue link: https://www.e-digitaleditions.com/i/1344205
18 / March 2021 powderbulk.com PBE PNEUMATIC POINTS TO PONDER Jack D. Hilbert, SME, Hatch, and Colin Barbeau, BMH Lead, guest co-author, Hatch Reader questions – A good source of information review and getting back to the basics! F rom time to time, we take the opportunity to answer questions we receive from readers, webinar participants, and conference and trade show par- ticipants (from the pre-COVID-19 times, that is). Typically, if we receive a question from one person, there are many other people with the same or sim- ilar questions as well. Plus, we're finding that more and more new people are getting involved in the field of pneumatic conveying and bulk solids handling in general, and a summary of questions like this can serve as a basic primer for those readers as well. As you know, pneumatic convey- ing relates to the transport of solids, using primarily airflow (although there are applications where other gases such as nitrogen are used) from a source point, through a con- veying line or pipeline, and into a receiver of some form at the solids' destination. A flow diagram of this is shown in Figure 1. In this article, we will look at some recent questions that relate to each of the pneumatic convey- ing system's five main elements: material feed, line charger, gas mover, conveying line, and mate- rial receiver. Material feed The pneumatic conveying's material feed is the source from which the material to be conveyed is received. Q: I mostly see information about pneumatic conveying from a storage silo to use points, such as another silo or a downstream process line, in a plant – can other sources of the material to be con- veyed be used? A: Absolutely, the material feed can be a production line where material is picked up on a continu- ous basis or a weigh hopper where several individual elements have been combined as a batch. In plants where raw materials are received in bulk from trucks or railcars, those areas can be the material feedpoints. There are applications where small quantities of materials are handled in 25-kilogram paper sacks, bulk bags, or flexible inter- mediate bulk containers, which can also be the material source point at the beginning of a pneu- matic conveying system. The way the material enters the pneumatic conveying system to con- trol the material flowrate and deal with specific material properties, along with the conveying system type and mode selected, will vary based on case-specific parameters. FIGURE 1 This flow diagram illustrates a basic pneumatic conveying system. Material feed Material receiver Line charger Gas mover Conveying line