1. Overview

The rake type scraper is usually used for mechanical discharge of sludge from horizontal sedimentation tanks. It can be divided into two forms: same flow scraping and reverse flow scraping.

2. Main parameters:

Pool width 3000mm

Pool length 14000mm

Driving mechanism motor power 0.75kW

Increase the motor power of the mechanism by 0.55kW

3. Main structure and working principle of scraper

3.1 Structure:

The machine is mainly composed of a platform, transmission device, rake plate hanger, guide rail, collision block, mud scraping device, slag scraping device, rake lifting device, electrical control system, and stroke control device.

The transmission device and scraper lifting mechanism are located on water, making maintenance and repair convenient. The rake plate hanger and scraper device are underwater and coated with anti-corrosion materials on the surface.

3.2 Working principle

When the equipment is running, the scraper plate falls down, and at this time, the scraper plate lifts up. The whole machine drives the scraper plate to scrape and collect the settled sludge at the bottom of the pool into the sludge collection tank at a certain speed; On the return journey, the scraper plate is lifted while the slag scraper plate falls down to collect the floating slag on the surface of the tank into the slag collection tank at a certain speed. The scraper plate does not disturb the sludge in the tank during the return journey, which is beneficial for the sedimentation of sludge. When returning to the starting position of scraping mud, the scraper rake plate automatically falls down, the scraper rake plate automatically lifts up, and proceeds to the next cycle.

4. Installation and acceptance

4.1 Track and laying requirements:

4.1.1 During installation, it is required that the top surface of the pool platform be flat, and the embedded iron of the installation track should be in the same plane.

4.1.2 The longitudinal straight deviation of the track shall not exceed ± 5mm.

4.1.3 The longitudinal levelness of the track shall not exceed 1/1000.

4.1.4 The relative height of two parallel tracks shall not exceed 5mm.

4.1.5 The joint positions of two parallel tracks should be staggered, and the distance between them should be greater than the wheelbase. 4.1.6 The track joints shall be connected with fishplates, and the deviation of the left, right, and upper surfaces of the joints shall not exceed 1mm, and the gap between the joints shall not exceed 3mm.

4.2 Equipment installation instructions:

4.2.1 First, place the platform and walking device on the steel rail, dismantle the transmission chain, and push the platform from one end of the pool body along the track to the other end to check for any jamming and correct the track.

4.2.2 Assemble the rake plate hanger, floating slag scraper hanger, scraper device, etc. in sequence according to the assembly diagram.

4.2.3 Place the whole machine at the end of the mud collection pit, lower the scraper to the bottom of the pit, and determine the position of the limit switch and limit plate of the crane at the end of the mud collection pit. Then push the scraper to the other end and determine the position of the limit switch and limit plate when the scraper rake plate starts working. Connect the steel wire rope to the hanger based on the lifting height of the rake plate.

4.2.4 Install strong iron limit devices at both ends of the track to prevent the travel switch from malfunctioning and causing the train to derail from both ends.

5. Maintenance and trial operation

5.1 Trial operation

After the installation of each component is completed, each part can only be driven for trial operation after being checked for firmness, reliability, and no faults. After there are no issues, fill the pool with clean water and press the start button for trial operation. When the mud scraper runs continuously for more than 24 hours and there are no abnormalities after inspection, sewage can be injected.

5.2 Maintenance and upkeep

During maintenance and repair, the following should be done:

5.2.1 Lubricate the seat bearing 1-2 times a month.

5.2.2 Before starting up, check whether there is any dirt on the lifting wire rope and whether the lifting limit screw is firm to avoid misoperation.

5.2.2 Check if the connections of water components are loose.

5.2.3 If the rubber scraper is severely worn and corroded, it should be replaced.

5.2.4 Conduct major repairs once a year.