Regarding steam-jet vacuum systems
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What is the highest vacuum level that a steam jet vacuum pump can achieve? It is said to be able to reach -0.0995 MPa. Is such a high level of vacuum actually needed?
This post was last edited by Myth/ty Taotao on 2017-12-20 at 15:02. It does exist, but the drawback is that its suction capacity is very low; it should be around 300 M3/H, which would be considered high. It’s far inferior to fans, and the vacuum level achieved by these fans is also poor.
This post was last edited by 402122290 on 2017-12-20 at 15:13. -0.0995 MPa corresponds to a gauge pressure of 500 Pa; using multiple stages in sequence can result in a lower value, with the gauge pressure being around a few dozen Pa. This information was found online and has not been verified
The vacuum pump manufacturers also claim that such a high level of vacuum can be achieved, but it’s not clear what the actual performance is like in practice, what the stability levels are, and how high the energy consumption will be
Our old workshop used a three-stage system with a pressure of around 2000 Pa; it’s no longer in use now. The new equipment employs water-ring–Roots vacuum pumps. It is no longer allowed to use homemade boilers to generate steam; the energy consumption is much higher than that of mechanical pumps, and there is too much wastewater which makes treatment difficult and results in high costs. It’s likely that such systems are used very rarely these days
The current water ring–Roots vacuum pump system achieves an absolute pressure of 10 Pa when idle, and its operating pressure is only 2000 Pa. What’s important is its low energy consumption – the operating current is around 50 amps only, so the electricity cost for a day is less than 1000 yuan. Meanwhile, the external steam we use costs 230 yuan per ton; I heard that previously more than 2 tons of steam were used per hour, so there’s no comparison in terms of energy consumption
-0.0995 MPa – this value seems difficult to work with; 500 Pa may not be achievable using a simple water ring pump, but it can be achieved by adding a Roots pump
Turbogenerators use this level of vacuum