Coal-containing water purifier ZJ/DH-II type sewage filter cyclone multi-layer purifier

Coal Water Purifier ZJ/DH-II Type Sewage Filter Cyclone Multi-Layer Purifier

1. Overview

In the treatment of high-suspended solids sewage, the ZJ/DH-II sewage purifier demonstrates significant technical advantages. It does not require a pre-sedimentation tank and can rapidly and continuously purify sewage with SS ≤ 30000 mg/L to 5–50 mg/L. This technology can handle sewage with SS up to ≤ 90000 mg/L, providing a new approach for treating high-concentration ash slurry water and solving the challenges of ash slurry water reuse.
2. Scope of Application
Suitable for the treatment and reuse of concentrated ash slurry water (including coal-containing wastewater) in thermal power plants;
Suitable for water treatment plants in towns, industrial, and mining enterprises using various rivers, lakes, reservoirs, etc., with water turbidity less than 3000 mg/L as the water source, serving as the main water purification device;
For lake water sources with low temperature, low turbidity, and seasonal algae;
Used in the circulating water systems of the metallurgical industry to significantly improve the quality of recycled water;
3. Main Features
Short process flow, low failure rate, stable and reliable operation;
Strong processing capacity and high efficiency. The equipment can handle loads up to SS ≤ 3000 mg/L, with a maximum of SS ≤ 9000 mg/L;
High design load, wastewater retention time ≤ 30 minutes;
Small equipment footprint. The system does not require pre-sedimentation tanks, sewage regulation tanks, sludge tanks, or clean water tanks, and can be designed as a conventional transition pool to save space;
High-quality treated water with SS = 5–50 mg/L, preventing ash accumulation in cooling towers and water seal tanks, and enabling reuse for furnace sealing;
PLC-controlled with a high degree of automation, reducing labor intensity for workers;
Low equipment sludge discharge volume, high sludge concentration, and low moisture content;
Easy operation, long filter media life, backwashing cycle of 0.5–1 month, offering significant water and energy savings, as well as environmental, social, and economic benefits;
Maintenance-free equipment body, reducing maintenance workload;
Single lift operation for equipment, saving investment in supporting electromechanical equipment and reducing power consumption;
Factory production mode ensures high precision, quality, and aesthetics of the equipment, improving water production quality;
Factory production mode allows for batch production, shortening construction time.
4. Working Principle and Structure
The ZJ/DH-II sewage purifier is an improved version of the original DH-type sewage purifier. It integrates physical and chemical reactions, combining direct current coagulation, critical flocculation, centrifugal separation, shallow sedimentation, dynamic filtration, and sludge concentration technologies. It is a compact combined device that completes rapid multi-stage purification of wastewater in a single tank within a short time (25–30 minutes).
The purifier is a steel tank with a cylindrical upper-middle section and a conical lower section. From bottom to top, it consists of the sludge concentration zone, coagulation zone, centrifugal separation zone, dynamic filtration zone, and clean water zone. Direct current coagulation and critical flocculation technologies replace the coagulation reaction tank. Flocculants and coagulant aids are added before and after the pump, utilizing the pump, pipelines, and water flow to complete hydrolysis, mixing, compression of the double electric layer, and adsorption neutralization. The wastewater then enters the tank at high speed along the tangential direction to quickly complete adsorption bridging and floc formation.
Centrifugal separation uses the high-speed swirl generated by the tangential entry of wastewater into the tank to create centrifugal force. Under this force, suspended particles and flocs are thrown against the tank wall and slide down along the inner wall to the conical sludge concentration zone under the action of the downward swirl and gravity. The wastewater spirals downward to a certain extent before converging toward the center, forming an upward swirl of clearer water that flows to the upper dynamic filtration zone. In the centrifugal separation zone, suspended particles (flocs) with a general particle size greater than 20 μm are separated into the sludge concentration zone. The wastewater enters the shallow sedimentation zone after centrifugal separation. The inclined tube sedimentation zone is designed based on shallow pool sedimentation theory. Dense inclined tubes are installed in the sedimentation area, allowing suspended impurities to settle along the inclined plates or tubes. The water flows upward along the inclined plates or tubes, while the separated sludge slides down to the bottom under gravity and is discharged collectively. This design increases sedimentation efficiency by 50–60% and treatment capacity by 3–5 times per unit area. The effluent from the upper part of the shallow sedimentation zone enters the dynamic filtration zone for further adsorption and filtration. The filtration zone uses suspended filter media with high surface area and strong adsorption capacity, capable of intercepting suspended particles larger than 5 μm. Filtration occurs in a dynamic state, preventing filter media clogging, and allowing adsorbed particles to detach and settle back into the separation zone, resulting in a long backwashing cycle (0.5–1 month). The wastewater is discharged after multi-stage solid-liquid separation and purification.
Suspended particles separated by centrifugal force, shallow sedimentation, and filtration enter the sludge concentration zone under centrifugal force and gravity. In the upper-middle part of the conical sludge hopper, particles aggregate into a whole under cohesive force, maintaining relative positions and settling together. In the lower-middle part of the sludge hopper, the SS is very high, and the liquid between particles is squeezed out, resulting in concentrated and compacted solid particles discharged from the bottom of the cone. The general sludge moisture content is ≤ 90% (sludge discharge volume is only 1/6 of traditional processes).
5. Typical Application Process
Used for retrofitting and new projects of ash slurry water treatment in power plants. The specific process varies slightly depending on the existing facilities and site conditions, but the basic process system remains consistent.

Overflow water from the slag conveyor flows by gravity into the drainage tank, which serves as a regulation tank. The regulated sewage is lifted by a slurry pump, and flocculants and coagulant aids are added before and after the pipeline mixer. Direct current coagulation reaction is completed in the mixer, and the wastewater then enters the (cyclone) sewage purifier. After processes such as centrifugal separation, gravity sedimentation, dynamic adsorption filtration, and sludge concentration, clean water is discharged from the top of the purifier and flows by gravity into the cooling tower. After cooling, the water temperature is 30–35°C, and it enters the clean water tank before being pumped to reuse points for furnace sealing and slag conveyor chain cooling. The concentrated sludge generated from ash water treatment is discharged into the sludge tank and then pumped to the slag conveyor for cyclic treatment.

6. Equipment Specifications and Models