Rotatable Surface Filter for Sewage Sludge Separation
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Solution Overview
Problem
Current methods for separating sewage sludge into liquid and solid phases are inefficient, particularly in small-scale wastewater treatment plants, where investment costs and operational complexities hinder effective thickening and dewatering processes, leading to high disposal costs and environmental challenges like eutrophication.
Innovation Solution
A device with a surface filter system, comprising an outer and inner perforated plate with a filter material in between, where a tube inserted axially between the plates allows fluid flow to create pressure differences for effective separation and flushing, enhancing the separation efficiency by up to 100% compared to traditional methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a stationary surface filter is used in sedimentation tanks, then the structure is simple and easy to operate, but the separation efficiency is low and the process is time-consuming
Solution Approach 1:
The patent transforms the stationary filter into a rotatable filter assembly that can rotate around a vertical axis. This dynamic element allows the filter to process larger volumes of suspension by continuously moving through different zones, thereby increasing separation efficiency while maintaining structural simplicity through a single rotating component design.
Solution Approach 2:
The sedimentation tank is divided into multiple functional zones (feeding zone, sedimentation zone, thickening zone, discharge zone) that the rotatable filter sequentially accesses. This segmentation allows different separation processes to occur simultaneously in different zones, improving overall productivity without complicating the filter structure itself.
2Quantity of substance
If large tanks are used for sedimentation of large volumes, then the separation capacity increases, but the investment costs and space requirements increase
Solution Approach 1:
The rotatable filter assembly increases the effective processing capacity within the same tank volume by continuously moving through all zones multiple times. This dynamic operation allows a single tank to handle larger volumes of suspension compared to static filters, effectively increasing separation capacity without requiring larger tanks.
Solution Approach 2:
The continuous rotation of the filter assembly ensures that all zones are constantly utilized, eliminating idle time and maximizing the productive use of the tank volume. This continuous operation increases the quantity of suspension that can be processed within the existing tank size.
3Device complexity
If the surface filter is stationary, then the device complexity is low, but the filter cake formation reduces separation speed
Solution Approach 1:
The rotatable filter prevents filter cake formation by continuously moving the filtration surface, preventing solids from accumulating in one location. This simple rotational motion maintains high separation speed throughout operation without requiring complex mechanisms, resolving the contradiction between device simplicity and productivity.
Solution Approach 2:
The filter assembly periodically returns to the feeding zone to be重新charged with fresh suspension, creating a cyclic operation that prevents filter cake buildup. This periodic regeneration of the filter surface maintains high separation speed while keeping the device structure simple.
4Productivity
If overpressure or vacuum is applied to accelerate separation, then the separation speed increases, but the energy consumption and operational complexity increase
Solution Approach 1:
The rotatable filter utilizes the natural flow of suspension and gravity-driven sedimentation processes, eliminating the need for additional energy-intensive pressure or vacuum systems. The mechanical rotation itself provides sufficient movement to prevent filter cake formation and maintain separation speed without extra energy input.
Solution Approach 2:
The system uses the inherent properties of the suspension (density differences, natural flow) to drive the separation process, with the rotatable filter simply providing the mechanical movement needed to maintain efficiency. No external energy sources beyond the basic rotation mechanism are required, keeping energy consumption low.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device significantly improves the separation of sewage sludge into sludge water and solids, reducing disposal costs and environmental impact by increasing the solids content and facilitating aerobic bacterial growth, thus improving thickening efficiency and reducing the strain on biological wastewater treatment stages.
Implementation Method 1
a surface filter (11, 17) inserted into the sedimentation tank (10)... the surface filter (11, 17) separates the sedimentation tank (10) into a first, outer chamber (10.1) and a second, inner chamber (10.2)... the solid particles settle in the bottom area of the first chamber (10.1)
Implementation Method 2
the solid particles settle in the bottom area of the first chamber (10.1)... Due to the pressure difference between the first chamber (10.1) and the second chamber (10.2), the sludge water is forced through the surface filter (11)
Implementation Method 3
Due to the pressure difference between the first chamber (10.1) and the second chamber (10.2), the sludge water is forced through the surface filter (11)
Implementation Method 4
A fourth embodiment of the device according to the invention shows... a tube (20), which is preferably inserted in the axial direction AR between the two perforated plates (11.1, 11.2)... This tube (20) has holes (21) in its wall through which flushing liquid or gas can be forced
Implementation Method 5
The surface filter is preferably ventilated so that more aerobic bacteria settle on the filter material and are supplied with sufficient oxygen
Data Source
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AI summary
The invention relates to an apparatus and to a method for if separating suspensions for covering sludge, in particular sewage sludge. The apparatus comprises a sedimentation basin (10), into which aqueous suspension provided with solid material particles can be supplied via a feed line (13), and from which thickened sludge (8) can be discharged from the first chamber (10.1) of the sedimentation basin (10) via a first drain line (7). The apparatus is characterized by a surface filter (11, 17) which can be immersed in the suspension and which comprises at least one outer perforated plate (11.1, 17.1), an inner perforated plate (11.2, 17.2) arranged at a distance therefrom, and a filter material (11.3, 17.3) inserted between the two perforated plates (11.1, 11.2; 17.1, 17.2), and also a pump (9) which faces the inner perforated plate (11.2, 17.2) and which cooperates with a second drain line (14), via which filtrate (3) can be discharged from the second chamber (10.2) of the sedimentation basin(10).