overview
HF rotary grid cleaning machine, also known as circulating tooth rake grid cleaning machine or rotary solid-liquid separator, is a specialized water treatment equipment that can continuously and automatically intercept and remove various shapes of debris in the fluid. It can be widely used in urban sewage treatment, water supply industry, power plant inlet, and can also be used as a front-end screening equipment in wastewater treatment processes in industries such as textile, food processing, papermaking, leather, etc. It is currently one of the effective solid-liquid screening equipment.

Working principle
The HF type rotary grid cleaning machine is composed of a unique set of rake teeth assembled into a rotary grid chain. Driven by a motor reducer, the rake teeth chain rotates in the opposite direction of water flow.
When the rake chain is moved to the upper part of the equipment, it is guided by a plum blossom wheel and a curved rail, causing relative self-cleaning movement between each set of rake teeth. The vast majority of solid matter falls freely under the action of gravity, while the other part relies on the reverse movement of the cleaner to clean up the debris stuck to the rake teeth.
According to the direction of water flow, the rake chain is similar to a grid. The clearance between the rake teeth assembled on the rake chain shaft can be selected according to the usage conditions. When the rake teeth separate solid suspended and floating objects in the fluid, it can ensure smooth water flow. The entire process can be continuous or intermittent.

characteristics and application
The advantages of this device are as follows:
(1) Has a certain degree of self-cleaning ability, moves smoothly and without noise;
(2) There is no blockage phenomenon, which is very suitable for making fine grid cleaning machines with a spacing of 1-10mm. In actual production, using medium coarse grid cleaning machines with a spacing of 10-20mm also yields satisfactory results;
(3) Due to the support of the rake teeth and hooks, the trapped dirt will not fall down, and when flipped at the top, it is easy to remove the dirt;
(4) High degree of automation, high separation efficiency, low power consumption, no noise, good corrosion resistance, can ensure continuous and stable operation without supervision, equipped with overload protection device. At the same time, the equipment operation interval can be adjusted as needed to achieve periodic operation; It can also be automatically controlled based on the liquid level difference before and after the grille, and has a manual control function for easy maintenance, with minimal daily maintenance workload.
Given the above advantages, it can be widely applied in the screening of impurities in municipal pipelines, pre screening of sewage treatment, water intake points of water supply plants and cooling water inlets of power plants, pre screening of wastewater treatment in textile, printing and dyeing, chemical, leather, papermaking, brewing and other industries to prevent water pump blockage.

Equipment parameters
The equipment specifications are divided into HF300-3600 according to the size of the machine model. If the machine width exceeds 1800mm, it will be made into a parallel machine. The rake teeth gap is divided into various specifications such as 1mm, 3mm, 5mm, 10mm, 20mm, 30mm, 40mm, 50mm, etc. The selection is based on the water flow rate, lifting height, solid-liquid separation total amount, and the shape and particle size of the separated material. Different materials are also selected, and the equipment length is customized according to the design channel size.

Outline schematic diagram

B=machine width (channel width B1-100);
Rake tooth working face=machine width -160;
H=Canal depth; H1=slag discharge height;
H2=H+H1+1400, α=installation angle (65 °~80 °), specific parameters are shown in Table 1-2 HF grid equipment parameter table.

Calculation of water flow rate
Hourly water flow rate of grille: Q=K * (B-160) * h * V * 3600, where:
Q=water flow rate (m/h);
K=flow coefficient related to grille gap (see coefficient table);
B=width of the grille machine (m);
H=water depth in front of the fence (m), generally set at 1m or 0.3m below the channel depth;
V=overcurrent velocity, generally taken as 0.6~1m/s.

Main technical parameters

Table 1-1 Overcurrent Coefficient K

Grid gap (mm)	0.5	1	2	3	5	15	20	30
Flow coefficient K	0.08	0.1	0.12	0.27	0.36	0.42	0.5	0.6

control system
The control system can be selected or provided by the user, and can be used by connecting it to a three-phase power supply on site.
The on-site control box adopts on-site start stop control buttons, and the on-site electrical control box is equipped with equipment start and stop buttons, as well as start, stop, and accident signal lights. To save energy consumption, all signal lights are energy-saving. A motor protector is installed in the electrical control box, and the control cabinet can be equipped with a PLC remote control interface. This electrical control box adopts carbon steel anti-corrosion or stainless steel shell, and is rainproof outdoors.

Table 1-2 HF Equipment Parameters

model	HF300	HF400	HF500	HF600	HF700	HF800	HF900	HF1000	HF1100	HF1200	HF1300
Installation angle α	65~80°
Motor power (KW)	0.75	0.75~1.1					1.1~1.5			1.5~2.2
Rake running speed (m/min)	About 2
Machine width B (mm)	300	400	500	600	700	800	900	1000	1100	1200	1300
Rake tooth working surface (mm)	140	240	340	440	540	640	740	840	940	1040	1140
Canal width B1 (mm)	400	500	600	700	800	900	1000	1100	1200	1300	1400
Canal depth H (mm)	1500~12000 user-defined
Slag height H1	600~1200 user-defined (default 800)

Ordering parameters
1. Channel (equipment) width; 2. Channel depth; 3. Discharge height; 4. Rake tooth clearance; 5. Installation angle; 6. Rack material; 7. Rake tooth material; 8. Other requirements
explain:
1. The rack material is available in carbon steel and stainless steel options;
2. The rake teeth are available in stainless steel and nylon (ordinary nylon is not resistant to low temperatures, northern users should choose carefully).