Loose mixer element strands and twisted ribbon
PRIMIX manufactures and supplies products that vastly improve the heat transfer in heat exchangers. Pipe heat exchangers are applied in the industry for cooling or heating products, however, with a viscous product the heat exchanging ability of this type of heat exchanger can deteriorate significantly and therefore usage becomes uneconomical. By using mixer element strands the capacity of these systems can be improved. PRIMIX manufactures mixer element strands but also twisted tapes or ribbons.
Mixer element strands
When cooling or heating highly viscous products, the risk of tunnel effects is high. Because of the formation of a boundary layer, the product near the inner wall almost comes to a stand still; the consequence is that the heat transfer is restricted. There is a real chance that because of fouling the exchanger will continue to clog up with product. Due to the occurring differences in speed, there will also be a large residence time spread.
By applying PRIMIX mixer elements strands, the resulting boundary layer is reduced to a minimum; the result is that the stationary boundary layer is broken and there is a continuous replenishment and addition of new product, which will have a positive effect on the heat transfer. Also, the residence time spread will be better because the mixing improves. By using PRIMIX mixer elements strands the system pressure drop becomes larger; your feed pump must be suited for this naturally. Heat transfer improvements of 40 % with respect to an empty pipe are no exception.
PRIMIX manufactures mixer element strands from 4 mm diameter, and in the usual materials, such as the various types of stainless steel. Special versions, for which the inlet and outlet side of each mixing element is made with a sharp or rounded edge, are possible. Also, various surface treatments can be used.
Turned ribbon or Twisted tape
Twisted tape is a long strip of material of a defined diameter which is turned up into a spiral; it can be turned both left or right; this in contrast to PRIMIX mixer elements strands of which the rotation changes in fact after every 180 degrees. Also, the twisted tapes can be applied in order to increase the heat transfer, and can be supplied for both existing and new exchangers. Twisted tapes are manufactured to client specifications in our own production facility to a diameter of 100 mm in the standard types of material. Ask our specialists about the possibilities.