Problems with double-vessel vacuum dryers
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The materials produced by our company are dried using twin-cone vacuum dryers, with the moisture content required to be below 0.1; the melting point of these materials is 63.5 degrees. Hot water circulation is used for heating, with a water temperature of 52 degrees and a vacuum level of -0.08. The moisture level always stays around 0.2; in some cases, the situation even gets worse the more attempts are made to reduce it. What’s going on? The vacuum pipeline has been cleaned using steam, and the filter cloth inside the dryer has also been replaced. I seek advice. . . .
The materials produced by our company are dried using twin-cone vacuum dryers, with the moisture content required to be below 0.1; the melting point of these materials is 63.5 degrees. Hot water circulation is used for heating, with a water temperature of 52 degrees and a vacuum level of -0.08. The moisture level always stays around 0.2; sometimes it even increases. What’s going on? The vacuum pipeline has been cleaned using steam, and the filter cloth inside the dryer has also been replaced. I seek advice. . . . If you make a mistake earlier, it will only get worse the more you try to appease it
Check the steam pressure gauge for water – what is the steam pressure at 52 degrees? It should be around 10 thousand pascals. You have set the pressure too high
52 degrees of hot water – the temperature you manage to achieve must be lower than that! If it's behind the dryer wall, 45 degrees shouldn't be enough to provide heating. The corresponding saturated vapor pressure is only 10 kPa absolute pressure. Moreover, your material seems to be in a solid state; furthermore, you have only achieved a pressure of -0.08 MPa gauge (20 kPa absolute pressure) – how can evaporation occur from a solid-state material? ? ! !
Replace it with another pump that has a higher ultimate pressure, or use a pump with a higher pumping speed. However, be sure to check whether your heating system is compatible; it’s best to consult a reputable dryer manufacturer to develop a suitable solution