CONTINUOUS BULK DENSITY MEASUREMENT

The CentriFeeder line of feeders allow for both an accurate, real-time flow measurement, as well as near perfect control of flow rate and total. For blending applications, control the flow rate of an individual ingredient, or combine several CentriFeeders for near perfect recipe control. If you are controlling ingredients entering a batching process, use the CentriFeeder for controlling the total of one or more ingredients entered into the batch.

The CentriFeeder can be used for continuous bulk density measurement without cumbersome sampling or the stopping of flow. Continuous bulk density measurement allows you the option of measuring the bulk density of the entire flow of a product while in process which can lead to tighter control of the density by accepting and rejecting material based on the near instantaneous output of the CentriFeeder. This feedback as to accepted and rejected bulk density can be used to perform upstream checks on equipment or process procedures as well. Moreover, the CentriFeeder is typically repeatable to within +/-1.0 lb/ft³.

Below, are just a few of the ways that the Continuous Bulk Density Meter has been employed in the past. If you have your own application or if you would like to see if a Continuous Bulk Density Meter would be right for your process, contact us today.

If positioned after a large holding tank, silo or bin of stored material, a Continuous Bulk Density Meter can maintain the bulk density of a flow of product within a predetermined range. This range can be set by determining the upper and lower bulk density limits for the process. As product from the silo or bin is discharged, the material will flow through the Continuous Bulk Density Meter, which will output the real-time bulk density of the flow of product. When out of spec material passes through the meter, an alarm would be triggered that would actuate a downstream diverter, thus diverting off-spec material. When the bulk density of the flow of material returns within specification, product would again be channeled to the proper location. Because the response time is nearly instantaneous, the Continuous Bulk Density Meter will ensure that nearly all of the rejected material will be kept isolated from the accepted material.

For situations where product is in process and not stored in silos or bins, a Continuous Bulk Density Meter can be used in conjunction with a maintained level hopper. The size of the hopper would be determined by the required speed of the bulk density feedback (smaller hopper volume) or by the smoothness of the flow signal required (larger hopper volume). When installed in this type of application a level set point for the hopper would be set and, in order to maintain this level, the system would continually adjust the flow set point for the continuous bulk density meter in order to maintain the level in the hopper. Although the Continuous Bulk Density Meter would not be controlling the flow rate, the bulk density measurement would still typically be within +/-1.0 lb/ft³ Because the size of the hopper can be greatly reduced, the ability to signal upstream disturbances in the process is greatly increased by using the Continuous Bulk Density Meter in this way.

When control of the full stream of product is not practical or possible, the Continuous Bulk Density Meter can be used to measure the bulk density of a continuous stream of diverted product that would be measured and then immediately diverted back to the original product stream. In such a case, only a fraction of the full flow of product would be measured, however, due to the small amount of "stored" product - (the stored product is only the amount of product that collects above the continuous bulk density measurement device) - the density feedback that is received from the device is fairly indicative of the current upstream process conditions and can thus, be used to make determinations about the upstream process nearly immediately. The rejection of out of spec material would come, in some instances, in less than a second so the amount of out of spec material that could pass into the process would be nearly 0.

For processes that measure bulk density, one of the byproducts is volumes of out of spec material. This material could be considered waste, or it could be blended back into the main process or blended with in-spec material in a predetermined ratio. With two continuous bulk density feeders the accepted and rejected materials could be re-blended for packaging. A Bulk Density Controller would determine the flow set point for each of the two flows of materials, which, when blended, will maintain the bulk density set-point. With the bulk density controlled, each of the resulting packages would be filled to their proper weight and proper volume for near perfect package filling.