A device for separating solid elements from wastewater, in which the liquid is fed to a rotating drum consisting a slotted screen, and the impurities are torn off by a scraper. Ttreated water flows through the drum to the drain, and a lance with sprays washes the drum; device is used in many industries
A device for separating solid elements from a wastewater stream.
The liquid to be cleaned enters the device through connections built into its body and flows onto a rotating working drum made of a slotted sieve. Solid contaminants larger than the screen slot remain on the surface of the drum, from where they are then torn off by a scraper and discharged outside the device. Treated water flows through the drum and goes to the drain built into the lower part of the machine body.
Additionally, the device is equipped with a lance with clean water sprays, the task of which is to wash the drum of contaminants.
Screens with an external inflow are used in almost every industry.
Larger screen models are equipped with a drive with a compensating clutch, which ensures smooth operation and eliminates stress between the drive and the screen's drum, thanks to which the operating time can be significantly extended.
EMI screens are started with minimal revolutions and slowly accelerate to the operating speed. Soft start increases the life of the gear, the most important mechanical component.
Screen housing has a door, the opening of which stops the device. The operator can also force movement with the door open, making operation comfortable and safe at the same time. The set is completed by inspection windows providing access to key elements of the device.
The flushing system with a pressure-boosting pump allows the screen to be connected to the water mains without worrying about providing the pressure required to effectively flush the screen.
The complete mechanical pre-treatment station consists of a screen, a conveyor and screenings press. Combining the devices already at the design stage allows you to create a set that is easy to use while respecting the available space.
Mechanical separation, i.e. separating solid elements from the wastewater stream
Most industrial wastewater streams contain solids that must be removed before wastewater reaches the treatment plant equipment. Removal of solids is necessary to protect pumps, mixers, sensors and other system components from blocking or even damage. In EMI installations, we use two stages of mechanical pre-treatment: coarse and fine. Coarse pre-treatment removes the largest elements, with a cross-section above 20 mm, and is carried out at the inlet to the first pumping station, before wastewater comes into contact with any pump. Coarse separation devices include vertical screens, basket screens and step/hook screens. The purpose of fine mechanical pre-treatment is to further remove solids, with their cross-section dropping below 3 mm, most often to 1 mm, although in some cases it is appropriate to use even smaller cross-sections (up to 0.25 mm). At this stage, rundown and rotary screens are used. The latter type of screen is used in a system with external or internal inflow. Mechanical pre-treatment involves very low costs, mainly resulting from the consumption of water rinsing the screens. No reagents are used, and energy consumption is minimal. Mechanically pre-treated wastewater is suitable for further treatment by physico-chemical and biological means.
