Vegetable packaging plants always spend a lot of water. Often this entails high costs, as well as problems caused by a lack of fresh water and the need to dispose of waste water. Especially a lot of difficulties arise if the wastewater has a high salt content and is also characterized by a high solids content, providing high turbidity.
Many companies seek to reduce their water consumption and waste water disposal costs by reusing their process water. The main difficulty in this way is associated with the need to clean the liquid, and in particular, the separation of solid particles. As a rule, more than 90% of the particles in the stream have a minimum size - in the range of 2-50 microns, and it is very difficult to separate them, regardless of the method of separation or filtration.
Traditionally, water purification in packaging shops is performed using gravity separation (clarifiers). Despite their effectiveness, clarifiers require a large area and are relatively expensive. Although alternative solutions (apparatuses that remove particles using centrifugal force: for example, hydrocyclones) show worse results: they are able to separate only relatively large particles (more than 70 microns), and also quite dense (more than 1,9 g / cc) , and are mainly used for initial separation of sand (less than 2% of solid particles). In addition, the high speed of rotation of the flow in the hydrocyclone prevents the processes of coagulation and flocculation.
The newly created innovative hydrodynamic separator Naticadeveloped by the company AquaHD, free from the limitations of traditional particulate separation processes. Natica works by creating centripetal forces to separate particles under low pressure (1 bar).
В Natica water flows through a special round structure. The passage of water through a circular structure allows you to create high centrifugal forces (6-8 G) under low pressure. Due to the high centrifugal forces, the particles are concentrated in the outer perimeter of the separator. Due to the laminar flow, the particles remain in the outer layer of the perimeter and do not mix with pure water inside the separator. A specially marked outlet design separates a stream rich in particles (near the outer perimeter) and a stream of pure water. Particles that have been removed from the water will be further processed by thickening and dewatering the sediment, where water will be sent to the beginning of the process. The illustration below illustrates the principle of operation. Natica:
Due to high wastewater tariffs AquaHD recently installed a water purification and recycling system in a carrot packaging complex in Israel.
In the storage, water was continuously drained from the washer (several seconds every few minutes) into the designated pit and returned to the head of the washer for transporting food. When the solids content in the pit became too high (every few days), liquid was drained from the pit and fresh water was added.
System AquaHD was installed next to the pit and continuously pumped water out of the pit, cleaned it and sent clean water from the pit to the head of the washer. This configuration made it possible to continue the operation of the pit without the need for frequent replacement of water in the pit, which led to large flows of heavily loaded wastewater into the sewer lines.
The graph below shows the processing results:
The equipment was installed in the storage in a limited space (inside the existing complex) and without interfering with the daily operation of the packaging lines.
As you can see, the separation system AquaHD was able to achieve very high particle removal efficiency (over 90%) and produced high quality water regardless of the composition of the inlet liquid. The compactness and modularity of the system makes the hydrodynamic separator a very suitable solution for packaging shops who want to process the flow of water for discharge into sewers, into the environment or want to reuse water.