 Bob Kolatac Metalfab Technology Manager Visit Website |
Bob Kolatac has been Metalfab’s Technology Manager since 2001, and first started in the materials’ handling business in May 1968 as a Laboratory and Field Service Technician testing and developing discharging and metering equipment for a wide range of customer applications. Today, he is involved in research and development and is responsible for pre-sales equipment selection and sizing, lab testing, and field service projects worldwide.
Bob received a Certificate of Industrial Chemical Technology from Newark College of Engineering (1970); a BS in Industrial Engineering (1977); and a MS in Management Science from New Jersey Institute of Technology (1981). He has written and published numerous articles on feeding and conveying of dry bulk materials, is a contributing chapter author in the “Bulk Materials Handling Handbook”, and has led numerous engineering seminars on metering of bulk solids materials in the US and abroad.
Metalfab, Inc. has more that 35 years of experience as a manufacturer of dry bulk material handling systems and equipment inclusive of their proprietary MetaTech™ Volumetric Feeders and Better-Weigh® Gravimetric Feeders, Posibin™ Storage Bins, Bin Activators, Bulk Bag Loaders and Unloaders, Convey-All™ Flexible Screw and Vibrating Tube Conveyors, and other specialized equipment including PAC Storage and Handling Systems for the Power Generation industry.
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Feeders Q&A
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We are considering installing a sample thief in order to sample and characterize powder flowing through our system. The line in which we intend to install the thief is a 16-in diameter aluminum line orientated vertically and in some locations 65 degrees from horizontal. Powder is fed into the line via a rotary feeder at about 50,000 lb/hr. The density of the power is 25 lb/cu ft. Internal pressure in the line is 10in. WC of Nitrogen. Do you have any recommended installation tips and manufacturers of such devices?Answered March 29th, 2010 by Expert:There are various methods and techniques used for sampling in order to obtain a representative sample for evaluation, testing, quality control, etc. Guidelines for sampling solids [liquids and gases as well] have been established and can be sourced through ASME, MIL STD’s, ANSI/ASQC, ISO 9000 Quality Control Procedures, even the National Institute of Oilseed Products have established sampling procedures!
Books have been written on the statistical relevance of sampling and how results affect certification of final product quality or in the evaluation of production efficiency. Physical sampling is one method of statistical quality control.
Sample size and sample frequency will be dictated by process and individual plant QC standards.
Generally, sampling standards are divided into three types of inspection: normal; tightened, and reduced inspection. Normal cycles are based on initial production runs and process, similar to start up phases in a typical plant; tightened sampling is incorporated if a history of plant problems or quality control issues have occurred, basically more frequent and detailed sampling; reduced sampling is used when sampling is required for QC issues but do not occur frequently because historical data has proven the plant production to meet specification.
We assume you have a Sampling Plan in place, including the frequency of sampling, the methodology of how the sample will be extracted, and any specific guidelines you intend to use.
Obtaining a representative Sample can be accomplished through various means, either a portion of product flow or a complete cross section of product flow by means of a suitable sample device, often call a sample thief.
As you have noted, you are already considering installation of a sample thief. A question a supplier will ask is if you are going to do a point of entry type sample or an entire cross sectional sample, which would require a full diverter installed in the transport line.
As far as sample sources, you need to look no further than Powder/Bulk Solids for a complete list of companies that manufacture ALL types of samplers and have engineering expertise specific to your needs.