Double cone rotary vacuum dryer is a set of drying equipment, mixing, vacuum drying in one of its people, as the classical equipment application is simple, convenient and double features, it has a practical and economic, is difficult to substitute other equipment. But in the drying speed of drying under different double cone rotary vacuum dryer and time is also a gap. Below we look at it what disadvantage.
Material drying process, first of all is the material surface water is heated and vacuum equipment removal, material surface water from vaporization decreased, and the formation of the temperature difference between the internal and surface of material. Internal moisture in the temperature difference, continuously to the surface diffusion and vaporization, at the surface. In addition, in the vacuum drying process, at the same time there is a pressure difference, the water molecule vaporization accelerated moving to the vacuum of space. So in the vacuum drying process, factors affecting the drying speed vacuum dryers have:
One is the dry material situation (such as material shape, size, stacking method), moisture content, density, viscosity and other properties of the material itself. In general, fine and uniform particles, piled up loosely, thin thickness, internal moisture easily spread. If raising the initial temperature, material by vacuum filtration pretreatment, reducing the material moisture content and so on, can improve the speed of vacuum drying. [1]
Another is the vacuum degree is higher, more conducive to water at lower temperature vaporization, but vacuum through the Gogh Blize conduction, will affect the heating effect of the material. In order to improve the drying speed, should according to the material considering the characteristics of vacuum degree. Usually, the vacuum degree should not be less than 1 * 104Pa.
Double cone rotary vacuum dryer should pay attention to the correct mode of operation:
Before the operation to check the vacuum pump, pipe joints, stuffing for leaks, inlet, outlet seal is good, a vacuum gauge response is a sensitive. Open cooling water valve check heat pipe joints, stuffing for leaks, the pressure gauge response is a sensitive. Check the instrument cabinet, button, indicator light is normal, check the grounding wire is good, there is no leakage, short circuit phenomenon. Refill grease, starting motor run empty, listening to the noise is normal, if not normal, should check out the source of the noise, and to exclude.
After the examination will be required to dry materials into a container (powder, granular, small pulp material by vacuum feed), and then close the feeding hole. Close the vacuum valve, open the vacuum pump, the negative pressure of a double cone rotary vacuum dryer container (600 - 755 mmHg). Then turn on the power switch, start double cone rotary vacuum dryer machine, press the button to start work, rotary dryer. The valve opening heat carrier, let the heat carrier into the drying container interlayer, according to the process of testing.
Drying is completed, first turn off the heat carrier injection valve, and then to the interlayer cooling water, cooling to room temperature to be material, stop vacuum. Open exhaust vacuum valve, close the motor, stop the double cone rotary vacuum dryer rotary, open hole cover material. |
