How to control the MVR pressure
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Could someone who is an expert in MVR please help answer this: in the MVR process, how is the pressure in the separation chamber controlled?
Someone told me before that the pressure in the separation chamber is controlled by variable frequency of the compressor; I don’t quite understand it. For example, the pressure at the top of a distillation tower is controlled by the outlet vapor phase or by a vacuum pump; however, since an compressor is involved in the MVR process, it’s not entirely clear.
The pressure in the separation chamber is at the level of the compressor inlet pressure, and it is primarily controlled by a vacuum pump. An automatic control valve can be installed on the pipeline leading from the vacuum plate exchanger to the vacuum pump; by setting the appropriate vacuum pressure corresponding to the evaporation temperature, this system can also be used in applications involving thermosensitive low-temperature evaporation, with stable operation of the system
The pressure in the separation chamber is controlled by the system, that is, by controlling the evaporation temperature, depending on the value you specify in your design
Thank you for your reply; you are referring to the situation of negative pressure evaporation. What about at normal pressure?
Thank you for your reply; you are referring to the situation of negative pressure evaporation. What about at normal pressure?
Control schemes are diverse; generally, control is achieved by adding supplementary steam.
If the heat balance of the entire system results in a surplus, a condenser can also be installed after the separator, with the amount of condensation used for control. All of these need to be reflected in the process flow diagram.
First, it is necessary to understand the principles behind pressure fluctuations, and then take appropriate actions; one cannot act randomly. Otherwise, you will end up in trouble.
Controlled by a turbine steam compressor. Generally, there is an inverter, with automation via PLC or DCS.
The pressure in the separation chamber is determined by your evaporation temperature, while the stability of operation depends on the suitability between your compressor and the heat exchange area; if the area is too small, the centrifugal compressor is prone to surge, while the rotary vane compressor will experience overcurrent.