Mechanical filter is also called pressure test filter, which is mainly used to reduce the turbidity of water and remove suspended matter and impurities in water.

This equipment is an oval container, with elliptical pressed heads on the top and bottom. There are three pillars at the bottom. Its body and the inner wall of the pipe are coated with high-strength anti-corrosion protection. For filter materials, there is a water inlet distribution device on the upper part and a dome-shaped perforated plate on the lower part. A compressed air pipe is also installed on it to loosen the filter layer during back washing.

On the outside, there are water inlet, outlet, backwash water inlet and drainage, and accessories include pipes, valves and pressure gauges.

Ultrafiltration technology is an advanced membrane separation technology, a kind of membrane filtration between microfiltration and nanofiltration. Ultrafiltration membrane technology, based on sieving and taking pressure as the driving force, is a membrane separation process for separating machines.

Particles, colloid, bacteria, heat sources, organic matters and the like in water can be effectively removed by an ultrafiltration membrane. The technology is suitable for various production processes for the purpose of separation and concentration as well as purification. It is widely applied to industries such as light textile, chemical engineering, medicine, food, green-electronics.

The ultrafiltration process avoids phase change, adopts normal-temperature operation and is particularly suitable for separation of thermosensitive substances; and furthermore, it has high temperature resistance, acid and alkali resistance and oxidation resistance and can be used continuously for a long time under the condition that the PH is 2 to 11.

Semi-osmosis using a reverse osmosis membrane, namely a water-permeable and salt-impermeable principle, is to overcome the osmotic pressure that freshwater in the water is concentrated into saline water after permeating the membrane by external pressure and enable the water to permeate the membrane. The water is divided into two parts, wherein one part is the saline water containing a large amount of salt; and the reverse osmosis system is to separate out inorganic salt in the water through the reverse osmosis membrane by the high-pressure action, remove organic pollutants and bacteria and intercept pollutants in the water. The reverse osmosis technology is applied to a water treatment industry; and by the reverse osmosis technology, impurities such as organic matters, viruses, bacteria and microorganisms in the raw water can be effectively removed, so that more pure and more stable water quality can be achieved, and the operation level and the automation degree of the whole process can be increased.

DTRO is one type of DT, a DTRO membrane technology, namely a disk tube module technology, is divided into three types of DTRO (disc tube reverse osmosis), DTNF (disc tube nano-filtration) and DTUF (disc tube ultrafiltration), and it is a patent type membrane separation module. The technology is developed specially for filtration and separation of high-concentration material liquid and has been successfully applied for nearly 30 years.

The disk tube membrane module mainly comprises an RO membrane, a flow guide disc, a center pull rod, a shell, flanges at two ends, various sealing pieces, connecting bolts and the like. A filter membrane and the flow guide disk are stacked together, are fixed by the center pull rod and the end cover flanges and then are placed into the pressure-resistant shell to form the disc tube membrane module.

The material liquid enters the flow guide disc at the bottom through a flow guide channel after passing through a gap between the membrane stack and the shell (as shown in figure), the treated liquid rapidly flows through the filter membrane in the shortest distance, is reversed by 180o to another membrane surface and flows into the next filter membrane so as to form tangential flow filtration from the circumference to the circle center of the flow guide disc, to the circumference and then to the circle center, and the concentrated liquid flows out of the flange at the feeding end. While the material liquid flows through the filter membrane, permeated liquid is discharged continuously through a center collection tube. The concentrated liquid and the permeated liquid are isolated by an O-shaped sealing ring arranged on the flow guide disc.

The DTRO module adopts open type flow channel design and the effective flow channel of the material liquid is wide, so that physical blockage is avoided.

•Minimal scaling and pollution phenomena

The flow guide disc with convex point support is adopted, and the material liquid forms a turbulent flow state in the filtering process, so that membrane surface scaling, pollution and concentration polarization phenomena are reduced maximally, and it is allowed that the highly polluted water sources with SDI value being up to 20 are still free from the risk of contamination.

• The membrane has long service life.

The DTRO membrane module effectively reduces the membrane scaling, reduces membrane pollution and has long cleaning period; meanwhile, based on the special structure and the hydraulic design of the DT, the membrane module is easy to clean and the flux restoring ability after cleaning is very high, so that the life of the membrane is prolonged. Project practice indicates that even if in direct treatment of the permeated liquid stock solution, the life of the DT membrane can reach to more than 3 years, which cannot be realized for the general membrane treatment system.

• High cycles of concentration

The operation pressure of the DTRO module has three optional grades (75 bar, 150 bar and 200 bar), and the DTRO module is the membrane module with the highest pressure grade in the current industrialized application; in some application with high cycles of concentration, the solid content can reach to more than 30% and the concentration cycles are high.

• The module is easy to maintain.

The DTRO membrane module adopts standardized design and the module is easy to disassemble and maintain; any one filter membrane and other parts can be inspected and maintained easily by opening the DT module; the module is simple to maintain; when there are not enough parts, less membranes and flow guide discs are allowed to be installed without affecting the use of the DT membrane module; and all the maintenance work can be completed on site.

The EDI technology is also named as a continuous electric desalination technology, which scientifically integrates an electroosmosis technology and an ion exchange technology; directed migration of ions in the water is realized under the electronic effect through the selective permeation action of anionic and cationic membranes on anions and cations as well as the exchange action of ion exchange resin on the ions in the water, so that the water is deeply purified and desalted; and filling resin is continuously regenerated through H+ and OH- generated through electrolysis, therefore in the process of treating water by EDI, the resin can be regenerated without acid and alkali, and a combined process combined with secondary reverse osmosis can be operated continuously for a long time. The water quality of the produced water can reach to 10 to 15 MΩ.cm, or can reach to higher water quality which high-purity water has. Stable deionized water can be produced by the EDI instead of the traditional mixed ion exchange technology (MB-DI).

• The produced water has the best stability and higher water quality.

• Through modularized production, PLC fully-automatic control can be realized.

• High-purity water meeting the requirements of users can be produced continuously.

• The concentrated water can be recycled without acid-alkali regeneration.

It is convenient to apply, operation and maintain and halt caused by regeneration is avoided.

Ion exchange is that oxygen ions and anions in the water are exchanged with H+ of cationic resin and OH- of anionic resin in an exchange column when the water passes through the ion exchange column, so that the desalination aim is fulfilled.

Through different combination of anionic and cationic mixed columns, the water quality can reach to a higher requirement, and it is the current mature device for commonly preparing pure water and ultrapure water. Ion exchangers can be divided into a cation exchanger (softener), an anion exchanger and a mixed ion exchanger.

The series of ion exchange equipment is to fill the same exchange equipment with cation exchange resin and anion exchange resin which are mixed according to a certain ratio and completely mix the anion resin and the cation ion by nitrogen.

The two kinds of resin particles are arranged mutually tightly, equivalently, countless level cation and anion exchange equipment is connected in series to operate. In the mixed bed, anion and cation exchange is conducted simultaneously, so it is favorable for balance of exchange reaction; and the reaction speed is high and the exchange reaction is conducted completely, so pure water with very high purity can be prepared.