Drying equipment solids feeders

The machine should have the screw diameter D > 30 mm, with length to diameter ratio L/D > 40. The extmder must provide an easy access to the reactive medium as well as the quenching capability with either screw or barrel removal. It must be fully instrumented with temperature and pressure sensors all along the barrel. It should offer the possibility of working under dry inert atmosphere, and have the capability of closed-loop control operation with an appropriate set of sensors. The machine should be equipped with a minimum of three feeders for solid and two for liquid ingredients. At least one vacuum system with cold trap is necessary. 

Christianson Scientific Equipment supply the Fritsch Analysette 22 laser particle sizer which operates over the particle size range 0.16-1250 pm. This is a universally applicable instrument for determining particle size distributions of all kinds of solids which can be analysed either in suspension in a measuring cell or dry by feeding through a solid particle feeder. In the Fritsch Analysette 22, laser diffraction apparatus the measured particle size distribution is displayed on the monitor in various forms, either as a frequency distribution or as a summary curve in tabular form, and can be subsequently recorded on a plotter, stored on hard disk, or transferred to a central computer via an interface. The time required for one measurement is approximately two minutes. 

Solid (or dry) chemicals are sometimes used to prepare solutions for feeding. Many operators prefer to feed chemicals with metering pumps rather than dry feed equipment. Also, mixing liquid chemicals into the process water stream usually is more efficient. A weighted amount (using a continuous dry chemical feeder or a batch preparation approach) of the dry chemical is mixed with water to prepare the desired solution strength. Then the liquid is metered into the process water in the usual way. 

---