They allow the effective drying of slurries, slurries, pastes and filter cakes with short residence time, low product hold-up and superior mixing efficiency. Horizontal thin film dryers are characterized by low power consumption, self-cleaning heating surfaces and good accessibility.
Horizontal thin film dryers consist of a horizontal externally heated shell with end covers, the inlet and outlet nozzles for feed, vapour and final product, nozzles for the heating medium and a rotor with screwed on elements supported in external bearings. The wet product fed through the inlet nozzle is conveyed steadily by the rotor elements along the heated dryer wall in a thin film, allowing an optimum heat transfer and a high evaporation performance.
Vapours pass counter-currently to the product flow and leave the dryer close to the feed nozzle. Entrained particles are removed in the wet zone. Moisture levels of a few tenth of a percent up to 5% and more can be achieved. The residence time of the product is typically between 5 and 15 minutes.
The CONTIVAC NDP processor was developed by Buss-SMS-Canzler for use in production processes with special hygienic requirements. This processor combines the advantages of continuous thin film drying with a special rotating spray nozzle that allows for CIP cleaning. The individually adjustable heating and cooling zones in the thin film dryer open up new opportunities for thin film drying technology to be used in complex processes. The basic operations of mixing, reacting, flashing and drying can be carried out in the same machine, with several different substance streams being fed into the processor simultaneously. The CONTIVAC NDP processor offers manufacturers in the pharmaceutical, fine chemical industries and in the food and pet food industries new possibilities for improvement, which are not available with conventional batch machines.
Batch operated dryers have problems with products, which pass through a sticky, viscous phase during drying. Such cases require very long residence times, which can cause unwanted side reactions, thermal damage to the product, and/or colour changes. Experience has proven that the residence time in the CONTIVAC NDP processor can be reduced up to 500 times. Further advantages compared to batch systems result from the low investment and operating costs.