Angled Rake Device for Sewage Fiber Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing computing systems for sewage treatment plants are complex and unsuitable for installation downstream of an aeration tank, as they fail to effectively remove fine fiber agglomerations that can cause equipment failure and require a simpler, lighter structure that can be installed later by wastewater treatment staff.
Innovation Solution
A computing system with a pivotable ramp flap at the upper end of the rails and a single pair of rails, where the carriage is supported by a scraper during upward travel and the rollers are guided back onto the rails through ramp and bridge flaps, allowing for efficient removal of screenings and easy installation with a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional screening system with two pairs of rails is used, then the rollers can be continuously guided, but the construction becomes more cumbersome and complex
Solution Approach 1:
The carriage is made tiltable about a tilting axis, allowing it to dynamically change its orientation between upward and downward travel phases. This dynamic adjustment enables the scraper to be positioned on or off the rake as needed, while the tilting mechanism itself provides the guidance function that would otherwise require a second pair of rails
Solution Approach 2:
The guidance function is extracted from the rail system and integrated into the carriage's tilting mechanism. By making the carriage itself capable of tilting and positioning, the patent eliminates the need for the second pair of guidance rails, simplifying the overall structure while maintaining reliable roller guidance
2Productivity
If the scraper rests on the rake during upward travel, then screenings can be removed, but the rollers cannot pass over the open end of the rails
Solution Approach 1:
The system operates in periodic cycles, alternating between two distinct phases: during downward travel, the scraper rests on the rake to collect screenings, and during upward travel, the carriage tilts to lift the scraper off the rake while the rollers pass over the open rail ends. This periodic switching of positions resolves the conflict between screening removal and roller travel
Solution Approach 2:
The carriage's ability to tilt dynamically about its tilting axis allows it to switch between the two required configurations. The tilting mechanism is actuated at appropriate moments in the cycle, enabling the scraper to be in contact with the rake during downward travel and elevated during upward travel, thus accommodating both functional requirements
3Productivity
If existing screening systems are installed, then coarse contaminants are removed, but fine fiber agglomerates are not removed and cause equipment blockages
Solution Approach 1:
The screening system is installed at an angle in the open channel, creating a local screening zone with optimized geometry. The angled installation and the specific configuration of the rake and scraper create local conditions that are particularly effective at capturing fine fiber agglomerates that would otherwise pass through conventional horizontal screening systems
Solution Approach 2:
The patent applies the screening principle to a new context - installing the system downstream of an aeration tank rather than at the inlet. This creates a secondary screening function that copies the contaminant removal capability at a different location in the treatment process, specifically targeting agglomerates formed during aeration
Data Source
Figure 1
Figure 2~4
AI summary
A screening plant, particularly suitable for installation downstream of a settling tank to filter out agglomerated fibers, consists of a machine frame in which a carriage (10), on which the drive motor (15) is mounted, moves up and down. A scraper (14) is located on the carriage (10). During the upward movement, a pair of rollers (12) of the carriage (10) is positioned below rails (11), so that the scraper (14) rests on the screen (4) of the screening plant. At the upper end of each rail (11) is a switch (20) by which the rollers are raised back onto the rails (11) for the return journey after the collected screenings have been discharged.Since the motor (15) is mounted on the sled (10), a compact assembly can be realized which can be delivered ready for assembly and only needs to be inserted into a water-bearing channel by the personnel of a sewage treatment plant without any further adjustment work being necessary.