Also known as: coarse grate, rain grate, bar grating cleaner, reverse-pull grate cleaner

A reverse-rake格栅 is a large coarse格栅 equipment used for removing heavier solid suspended particles from water bodies. This device can continuously remove solid suspended particles from liquids, featuring reasonable design, simple structure, safe and reliable operation, and high degree of automation. It is widely applicable in water treatment facilities with large flow rates, such as urban sewage treatment plants, water intake of waterworks, stormwater pumping stations, and cooling water intake of power plants.

Section II: Features and Applications of Reverse-Flow Grating

During operation, debris may enter the traction chain, causing it to jam. Therefore, a sealed traction chain has been designed. It is mainly composed of chain plates, pins, and roller wheels. In operation, it is guided by the guide rails on the frame, with the roller wheels rolling on the rails, offering low resistance and smooth operation.

The underwater swivel wheel is made of stainless steel, equipped with wear-resistant copper bushes and self-lubricating bearings, eliminating daily maintenance for underwater components.

The slag-guard section features fixed bars, offering strong impact resistance and the ability to withstand significant water level differences.

Based on these advantages, the reverse-screen格栅 is applied in large water treatment facilities with high flow rates, such as wide river pollution control, stormwater pumping stations, river intake ports, and coarse格栅 in wastewater treatment plants.

Section 3: Anti-siphon Grating Structure Diagram

IV. Principle of the Counterflow Grating:

The dredging grate consists of a frame, a drive unit, transmission guide wheels, a rake chain assembly, and rake teeth, as well as slag baffles and slag boards. Under motor power, the traction chain rotates from bottom to top on the upstream side. When the rake teeth on the traction chain reach the upstream side of the baffles, the teeth are inserted into the gaps of the baffles and perform a cleaning action from bottom to top, scraping off the debris caught on the baffles into the rake, achieving high efficiency. As the rake teeth rotate to the machine, the debris falls off by gravity into the container or conveyor, effectively removing the debris.

V. Selection of Reverse Lift Grating

1. There are two types of格栅 separators: manual格栅 and recovery格栅. To minimize the harm of pollutants to humans, reduce labor intensity, improve efficiency, and achieve automatic control, mechanical equipment should be used as much as possible. When wastewater contains oils that can release volatile flammable gases, the power unit of the mechanical equipment should be equipped with explosion-proof facilities.

2. Determine the specific design and material of the grille based on the characteristics of the wastewater, such as the pH level and the size of the solids.

3. Large-scale wastewater treatment plants typically require two sets of grates and one screen. The spacing of the bars should be determined based on factors such as the type of wastewater, flow rate, representative debris type, and size. This ensures compliance with the requirements of the pump structure as well as subsequent water treatment structures and equipment. The first set uses coarse grates (50 ~ 100mm) or medium grates (20 ~ 40mm), the second set uses medium or fine grates (4 ~ 10mm), and the third set is a screen (<4mm).

4. Common cross-sectional shapes of grille bars include 20mm square, 20mm diameter circular, 10mm x 50mm rectangular, 10mm x 50mm rectangular with one semicircular end, and 10mm x 50mm rectangular with both ends semicircular. Circular grille bars have good hydraulic conditions and low water flow resistance, but poor rigidity and are prone to deformation under external forces. Therefore, it is preferable to use rectangular sections unless there is a specific requirement.

5. Typically installed at the head of the process line or at the intake of pump stations, this location is a bottleneck. To ensure safety, a backup unit or other means should be in place to facilitate maintenance of the product without interruption of water supply.

6. To protect power equipment, machinery and equipment are generally installed in well-ventilated grating rooms. Large and medium-sized grating rooms should be equipped with hoisting equipment for ease of equipment maintenance and daily cleaning of the grid waste.

6. Reverse Extraction Grating Maintenance:

Retrieval-style grates require maintenance for asymptomatic operations. Every three months, apply lubricant with a grease gun to the clean areas of the nozzles, introducing calcium-based grease. Quarterly or as needed, inspect and tighten all anchor bolts and alignment pins; if loose, they should be secured first. Machinery components should be free from foreign objects to prevent equipment failure. It is mandatory to replace clean oil in the oxidizer every quarter. Generally, when the clean oil spots are small to large, the function of the gearbox is affected as follows: temperature rise (the higher the line speed, the greater the rise); thermal efficiency reduction (the more significant the value); noise reduction; improved sealing effect; increased load-bearing capacity for the worm gear or shaft.

All operators of the reverse rake grates are often trained in basic principles and self-learning. Functions and layout standards, operation manuals, etc. Before starting, consider the following: Is the reducer smooth, is the oil fully filled, is the electrical appliance well connected, and is the motor's rotation direction correct? Then start listening to the unobjectionable operation, maintenance strategies for reverse rake grates. If abnormal operation is detected: stop the inspection, use a hard object to generally try to immediately clear obstacles, the system maintenance view should not affect the mechanical load, and should be repaired immediately, and the rake teeth should not pass over the pressure protection device.