Joseph Marinelli of Solids Handling Technologies Inc. has provided consulting services to the bulk solids handling industry since the 1970s. Through his company, Marinelli evaluates bulk solids flow properties and provides recommendations for bin and feeder design. At this year’s International Powder & Bulk Solids Conference and Exhibition, the bulk solids veteran is leading presentations on Particle segregation, volumetric and gravimetric feeder design, and other topics. In advance of his appearance at the Powder Show, Powder & Bulk Solids spoke with Marinelli about on-going issues in the industry that he will discuss at the conference.
Powder & Bulk Solids: What kinds of industries have problems with particle segregation?
Marinelli: Separation of particles is critical to the following industries:
- Pharmaceutical: Separation of active ingredients from the rest (sugar, cellulose) causes major problems with quality control. Large quantities of fine, active ingredient, or conversely, the lack of active ingredient, will prevent a drug from coming to market.
- Roofing shingles are dependent on a range the deposition of stones and colors with a range of particle sizes, in order to provide the 50-year shingle warranties being offered today.
- Batteries are filled volumetrically. If there are density variations due to segregation, the battery will not last as long as required.
Powder & Bulk Solids: Are there emerging technologies or pieces of equipment that are helping to resolve these issues? If so, please name some examples.
Marinelli: One approach being used is called a cone-in-cone design, whereby a shallow outer cone that would by itself flow in funnel flow is modified with the installation of an inner cone (open at the top and bottom) that will ensure mass flow through the inner cone, and force material to flow along the walls of the formerly too shallow outer cone.
Powder & Bulk Solids: Is it challenging for businesses to interpret and use data from flow properties reports? If so, why?
Marinelli: Sometimes it is a challenge as solids flow is typically not taught at the universities. Engineers are not aware of the science of bulk solids flow. Only through conferences such as given at the Chicago Powder Show are they introduced to the topics and science.
Powder & Bulk Solids: What is the benefit of learning to use this data more efficiently?
Marinelli: Flow properties testing is the basis for all work to identify a flow problem and to provide solutions to those problems. Modifications to hoppers that exhibit poor flow can only be provided with knowledge of solids flow properties.
Powder & Bulk Solids: How has feeder design changed over the decades? Have any recent designs made a major impact?
Marinelli: The feeder design is as important as the bin design. An improperly designed feeder will destroy the required flow pattern of the bin above. Mass flow screws and interfaces to belt feeders have been in use for years to ensure flow from bins and hoppers.
To learn more, come to the International Powder & Bulk Solids Conference & Exhibition this year and attend Joe Marinelli's presentations on May 4 and 5.