Integrated water purifier

　　1. Overview

　　Our company has developed and manufactured the FA‑type integrated, high‑efficiency, fully automatic water purification system, which boasts a simple process, eliminates the need for dedicated operator supervision, occupies a small footprint, requires low capital investment, and can be commissioned quickly.

　　This unit comprises seven major subsystems: water distribution, reaction, sedimentation, filtration, water collection, sludge collection, and automatic backwashing. It is equipped with inclined-tube packing and refined filter media of various specifications. The main vessel is fabricated from carbon steel, with both internal and external surfaces treated with a special anti-corrosion coating, ensuring a long service life, broad applicability, and outstanding performance. It is widely employed in the construction and renovation of large, medium, and small water treatment plants (stations).

　　The design treatment capacity of the project is 50 t/h.

　　2. Characteristics of Process Equipment:

　　2.1 During operation, the equipment automatically performs all processes—including reaction, coagulation, sedimentation, filtration, backwashing, and sludge discharge—using its own hydraulic action, eliminating the need for manual intervention.

　　2.2 Strong adaptability: Whether the source water has high turbidity or low turbidity, this equipment demonstrates exceptional adaptability, with effluent turbidity consistently below 3 mg/L.

　　2.3 Low operating costs.

　　3. Process Flow Diagram of Equipment Purification

　　(Note: The portion enclosed by the dashed line is the FA-type integrated fully automatic water purification unit.)

　　4. Process Description

　　After the coagulation reaction, the water enters the fully automatic water purification unit and first flows into the distribution zone at the bottom of the unit, where it is evenly distributed, its flow velocity is reduced, and it slowly moves into the high‑concentration flocculation zone for thorough coagulation. Under the guiding action of the inclined tube diversion section, the wastewater rises along the inclined tubes and enters the sedimentation zone. The settled sludge, acted upon by gravity, slides downward along the inclined tubes, while the descending flocs are carried by the hydraulic action of the diversion tubes into the sludge discharge hopper of the purification unit. Meanwhile, the clarified water that has passed through the inclined tubes flows from the upper part of the unit into the filtration chamber, percolating downward through the filter media; the flocs in the water are intercepted and removed by the filter layer. The filtered clean water collects at the bottom of the unit in the clear water zone and is returned via a connecting pipe to the clear water layer at the top of the unit. After being purified within the water treatment unit, the raw water flows into the intermediate water tank, from which a pump delivers it to the activated carbon deodorization and odor‑removal unit; following disinfection, it is then pumped to the points of use.

　　Sludge discharge and backwash wastewater disposal: The sludge settled in the high-efficiency, fully automatic water purification unit is automatically removed at scheduled intervals by the sludge‑discharge system. The discharged sludge and the filtered backwash water are conveyed to the sewer or a sludge pit for dewatering and further treatment.

　　① Sludge Discharge: After the water purification unit has been in operation for a specified period, the solenoid valve automatically initiates a sludge discharge cycle upon receiving a signal from the central control cabinet. Simultaneously with the opening of the electric drain valve, the pressurized‑water backwash valve also opens to provide auxiliary backwashing. (When the raw water turbidity is below 500 mg/L, a sludge discharge interval of T = 12 hours is recommended; the discharge interval is adjustable.)

　　② Backwashing and sludge discharge: After wastewater has been filtered through the filter bed for a certain period, the resistance of the filter bed gradually increases. When the water level rises to a specified height, automatic backwashing is initiated in the filtration zone.

　　Under the hydrostatic pressure of the clear water layer at the top, the backwash water is rapidly accelerated, and the clear water within the unit flows as usual.

　　The system operates in the reverse flow direction; when clear water passes through the filtration zone, backwashing of the filter bed is initiated. After a backwash duration of 3 to 5 minutes, the backwashing process automatically ceases once the water level in the clear‑water zone drops to a predetermined level. The backwash wastewater is discharged into a drainage tank and conveyed via a discharge pipe to the sewer or a sludge pit.

　　5. Operating Principle

　　Raw water and the coagulant are drawn by the feed pump, thoroughly mixed in a pipeline mixer, and then pumped into the reactor chamber of the unit. Within the reactor, coagulation takes place: suspended impurities, colloidal particles, and some microorganisms and bacteria in the water lose their stability under the action of the coagulant, forming larger flocs. These flocs settle in the sedimentation zone via inclined tubes, while the clarified water rises, achieving solid–liquid separation. After passing through the inclined-tube sedimentation section, most of the suspended solids, colloidal particles, microorganisms, and bacteria have been removed; however, the effluent still does not meet the required quality standards.

　　The FA‑type series water purification equipment employs a fully automatic, valveless filter as its filtration unit. After the settled water rises to a specified level, the resulting hydraulic head causes it to overflow into the filter bed, where it undergoes downward‑flow filtration through the filter media. The filtered water then overflows via the filter’s outlet pipe into the clear water tank for storage and subsequent use.

　　After operating for a certain period, the sedimentation tank accumulates settled solids, forming sludge. Once the sludge concentration reaches a specified level, the controller activates the solenoid valves on the sludge discharge lines to periodically remove excess sludge. The sludge‑discharge interval can be adjusted according to the turbidity of the influent; typically, each solenoid valve is set to discharge for one minute per hour.

　　After the filter bed has operated for a certain period, the continuous interception of suspended solids by the filter media leads to a gradual increase in filtration resistance, causing the water level in the siphon’s rising pipe to rise steadily. When the water level reaches the opening of the siphon‑assist pipe, water flows down through this pipe and, via the air‑removal pipe, carries away the air from the siphon’s descending pipe. Once the vacuum attains a specified value, siphoning is initiated: water from the reservoir flows upward through the filter media, performing backwashing. When the water level in the backwash tank drops to the elevation of the siphon‑break pipe opening, air enters the siphon, breaking the siphon action, thereby concluding the backwash cycle and allowing the filter bed to proceed to the next operational phase.

　　6. Performance Advantages

　　⑴ The water purification unit itself achieves fully automatic operation throughout its entire sequence of processes, including reaction, flocculation and sedimentation, water collection, water distribution, filtration, internal backwashing, and sludge discharge. The central control cabinet is equipped with a PLC interface, so operators need only perform periodic water quality monitoring; no further manual operation or management of the unit is required.

　　⑵ A high-concentration flocculation layer enables impurity particles in the raw water to undergo thorough collisions and contact, increasing the probability of adsorption. Consequently, it can adapt to a wide range of raw water temperatures and turbidity levels, achieving a high removal rate of particulate matter and, under certain operating conditions, also exhibiting algal‑removal capabilities.

　　⑶ The rapid sludge‑concentration chamber and the adjustable automatic sludge‑discharge system ensure that excess sludge is promptly removed, thereby maintaining a stable removal rate for particulate impurities.

　　⑷ High-efficiency flocculation and sedimentation ensure that the quality of the settled effluent remains consistently excellent.

　　⑸ The novel, original water-collection system and the most efficient collection head ensure more uniform and effective water collection, thereby not only enhancing the volumetric utilization coefficient but also minimizing the collection head loss.

　　⑹ The water purification system is fully automated, ensuring highly efficient filtration—when the raw water turbidity is below 1,000 mg/L, the filtered effluent turbidity can be maintained at approximately 3 mg/L—while also enabling automatic backwashing. This eliminates the need for separate electrical equipment such as backwash pumps or air compressors, thereby significantly reducing capital investment and lowering ongoing operating, maintenance, and repair costs.

　　⑺ The equipment has a low self‑consumption water rate of approximately 3%, which plays a positive role in conserving precious water resources.

　　⑻ It occupies a small footprint; compared with conventional water‑treatment structures, it can reduce the land area required by more than 50%, with an overall height of approximately 4.20 meters, and can be installed both indoors and outdoors.

　　⑼、Convenient for expansion, renovation, relocation, or repurposing at another site.

　　⑽ The construction period is short, amounting to one quarter of the typical construction cycle for conventional clarification and filtration facilities.

　　⑾ The clean water outlet shall be at a height of ≥2 m; the clear water tank may be constructed as a semi‑aboveground type, and the clear water pump may adopt a self‑priming suction method, which ensures more reliable operation.