EXTRAPOLATED CONSISTENCY ‘CONTROL’

     Conventional consistency control has its shortcomings. In normal systems where ‘good’ control of consistency can be achieved, the following parameters have to be robust, available, repeatable and be controllable. Constants, such as water pressure, water volume, control valve accuracy and repeatability are at best of times non-existent. In almost all systems, there is a great deal of interactions among all the different components, especially with the sometimes unavailability of a consistent supply of water. Another general shortcoming is the fact that in all but a few rare cases, the actual consistency transmitter is subjected to variances in stock flow past the actual sensor. This in turn will actually shift the zero of the instrument, which in turn will also cause the incorrect amount of water necessary for accurate control. 

     While accuracy is an important attribute of any consistency transmitter, it’s been seen over and over that by far its repeatability is the most needed accurate feature. Almost all manufacturers will give their transmitter specifications based upon the user keeping the velocity of the sensed medium between min-max values. Another difficulty, especially in a recycling environment, is dealing with the ‘what’ the measured medium contains. This is perhaps the most difficult variable to address effectively since most primary recyclers deal with ‘whatever’ is available to be recycled. Blade transmitters can effectively deal with certain mediums but not with all and certainly not with a constantly changing makeup. A higher generation of non-intrusive transmitters based upon beta particles or radioactive materials is another extremely expensive option, but likewise not without needed minimum requirements.

     These faulty readings will have a compounding effect upon the loop in question as well as upon the whole of the cleaning and delivery system. Since some faulty additions have been carried out, further problems are brought to light. These variations will cause adverse measurements which in turn will cause further errors attributable to the operators seeing the accurate readings. Since different conditions cause different readings for the same consistency, each operator will make his own unique corrections. Most of these corrections could possibly be more a negative assistance rather than a positive one. The greatest encountered problem is the non-repeatability of stated accuracy of the transmitter in question. By utilizing some (or all) of the other features of our site, systems could be improved to a level previously unattainable without greater outlays.