Strong chemical tolerance
Strong resistance to acid, alkali and oxidants Concentrate acids & alkalis, e.g., sulfuric acid, hydrochloric acid, sodium hydroxide, and oxidants, e.g., ferric chloride, high chlorine reagents, without neutralization, even till crystallizes.
Low-temperature & multi-effect design
CSRE MD adopts mult-effect, heat-recirculating and modular design. CSRE MD is driven by low-temperature heat sources.
CSRE MD effectively utilizes low-grade waste heats and energy consumption can be lower than 2-5kWh/ t of water.
MD work flow diagram
Utilizing residue/waste heat in plant, according to different components in waste water, MD concentrates waste water to a concentration close to saturated state for maximizing volume reduction and reducing total volume of subsequent crystallization, leading to low OpEx of whole process.
In ZLD process, the concentration and crystallization are two key steps. The choice of suitable technology and process can decrease total CapEx and OpEx. However, the existing multi-effect evaporation/MVR-crystallizs is high in CapEx, OpEx and maintenance cost. To resolve issues, CSRE develops MD crystallizer in house.
MD crystallizer, a combination technology of CSRE MD and proprietary non-metallic crystallizer, is constructed with non-metallic materials, modular and internal-channel design, operated at low temperature and negative pressure, and seamlessly integrated with CSRE MD. After concentrated to a subsaturated state, the saline water directly enters non-metallic crystallizer to carry out forced circulation crystallization at low temperature; the generated steam during crystallization can pre-heat feed of MD to promote heat efficiency.
The technology overcomes technical drawbacks of that traditionl MD cannot do crystallization and low anti-corrosion performance of metallic crystallizers. The MD crystallizer can be driven by electricity, steam, and low-grade heat, e.g., hot water, low-grade steam, solar energy, which broadens application areas of concentration and crystallization.
With the development of ZLD technology, MVR is attracting more and more concerns due to very less steam consumption and lower OpEx than multi-effect evaporator, and suitable for applications in the areas without steam/surplus heat or with high steam price. The same, MD can be integrated with mechanical vapor compressor to promote working efficiency. Thus, CSRE developed MVR-MD in house, which is a combination process of CSRE MD and MVR.
The temperature of flash steam generated by MD is increased by compression to promote efficiency of recycling and heating. Thus, the MVR-MD system can utilize generated flash steam by self to keep system running and just needs less steam for make-up after starting up, which substantially decrease energy consumption. Furthermore, the MVR-MD system is operated at negative pressure with high safety coefficient and suitable for clients in short of steam/surplus heat or having low price of electricity, e.g., coal-fired power plants. CSRE adopts non-metallic materials to construct system with modular and internal-channel design for promoting chemical-resistance and flexibility of system.
MD based ammonia extractor
With the developmenet of membrane technology, ammonia extraction from waste water through membrane processes absorbs more and more attention. CSRE is developing MD based ammonia extractor, MD extractor, for ammonia extraction at low temprature; the equipment adopts PTFE hydrophobic membrane as a barrier to isolate water containing ammonia from absorbent solution; volatile ammonia passes through membrane under ammonia partial pressure at the both side of membrane and is absorbed by absorbent solution.
The equipment with modular and internal-channel design is constructed by welding plastic materials, strong tolerance to chemicals and operated at low temperature and pressure with low OpEx and high safety. Feed and absorbent can be in-situ heated and cooled, respectively, which greatly promotes ammonia extraction efficiency.