Project description: bio-pharmaceutical wastewater treatment;
Equipment: MVR evaporator, with centrifugal compressor;
Main composition of feedstock: sodium chloride, sodium sulfate, organics and etc;
PH of feedstock: slightly alkaline;
Evaporation capacity: 3,000.00kg/hr;
Construction material: product wetted parts adopt 2205, non wetted parts adopt SS 304 or carbons steel per actual need.
Project Description
The bio-pharmaceutical wastewater was of complicated composition, containing inorganic salts, eg. Sodium chloride, sodium sulfate and others, and a certain content of organics. After evaporation trial, the MVR evaporator was proved to be workable with this bio-pharmaceutical wastewater. MVR evaporator, is an evaporation and concentration equipment with mechanical vapor recompression (thereinafter abbreviated MVR), recycling the secondary steam completely with compression.
Because there was chlorides contained in the feedstock, which is corrosive to stainless steel. In consideration of long term operation, the product wetted parts adopted 2205, and other non wetted parts adopted SS304 and carbon steel separately for less investment.
According to the characteristics of feedstock, a MVR evaporator is adopted to treat the bio-pharmaceutical wastewater. The feedstock was pumped into a condensate preheater and an exhaust preheater to be heated up before evaporation, and to take full advantage of talent heat of the condensate and the exhaust. After preheating, the feedstock entered the forced circulation evaporator to be concentrated till oversaturated, and then the oversaturated liquor was delivered into a centrifuge to be solid-liquor separated, the filtered salts was discharged or recycled, and the mother liquor was returned to the evaporator system to be concentrated again.
Secondary steam from the separator flowed into the compressor, it was compressed by the compressor and became high-temp and high-pressure steam, and entered into the evaporator to act as heating source again.
1 set of MVR and forced circulation evaporator is adopted for bio-pharmaceutical wastewater treatment, is able to meet the following demands:
1). the bio-pharmaceutical wastewater was concentrated to oversaturated, and then was filtered by a centrifuge to separate crystal salts from mother liquor, and the mother liquor was returned to evaporator system;
2). All components in the plant are well designed to ensure safety in production;
3). The forced circulation evaporator system can effectively prevent the blocking risk of heat exchange tubes caused by high concentration, and can slow the formation of scaling on the heat exchange surface at the mean time, improve the heat transfer efficiency, increase the continuous operation time of equipment, and reduce the cleaning frequency;
4). Two-stage heaters connecting in series, one was before the axial flow pump and the other one was after the axial flow pump, reducing the circulation flow of the pump, and is contribute to crystal growing.
5). The main configuration of the plant is as below:
a. One set of preheating system;
b. One set of forced circulation evaporator;
c. One set of MVR unit;
d. One set of demister system for ensure the quality of secondary steam entering the MVR device, to ensure the service life of the MVR device;
e. One set of PLC control system.
