Nested Conical Tray Separator Grit Re-Entrainment
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Solution Overview
Problem
Existing separators for removing grit from wastewater face efficiency issues due to upward flow agitation, which re-entrains settled grit, reducing separation efficiency.
Innovation Solution
A separator tray assembly with nested, substantially conical trays and baffles that restrict flow through apertures, creating an annular passage with a flow area not greater than the aperture, to inhibit upward flow and enhance grit retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If upward flow is allowed through the tray assembly, then de-gritted water can be discharged, but settled grit is agitated and re-entrained in the flow
Solution Approach 1:
The patent applies different flow restriction characteristics to different locations: the annular passage between adjacent trays has a flow area not greater than the aperture flow area, creating localized flow control at critical interfaces where grit settlement occurs. This selective restriction allows water to pass while preventing upward flow that would disturb settled grit.
Solution Approach 2:
The tray assembly is segmented into multiple nested trays with spaced-apart configuration, creating multiple separation zones. Each tray unit with its aperture and annular passage acts as an independent flow control stage, allowing progressive water discharge while maintaining grit settlement in each zone.
2Quantity of substance
If flow area of annular passage is increased, then water flow is improved, but grit re-entrainment increases
Solution Approach 1:
The patent precisely controls the flow area parameter of the annular passage to be not greater than the aperture flow area. This parameter constraint creates optimal flow conditions where water can discharge through the annular passage without generating upward velocities sufficient to re-entrain settled grit.
3Device complexity
If conventional tray design is used, then结构简单性 is maintained, but grit re-entrainment occurs reducing separation efficiency
Solution Approach 1:
The patent employs nested trays where smaller diameter trays are positioned within larger diameter trays, all sharing a common separator axis. This nested configuration achieves effective flow control and grit separation without requiring complex external structures, maintaining relative simplicity while improving performance.
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 solution effectively reduces grit re-entrainment, improving separation efficiency by obstructing upward flow and retaining de-gritted water, thereby increasing the amount of grit collected at the bottom of the separator.
Implementation Method 1
The low energy vortex allows grit particles entrained by the flow to settle on the sloping inner surface of each tray whereupon the particles gravitate towards and pass through the openings in the trays
Implementation Method 2
The influent duct is arranged to provide a tangential inlet such that a low energy vortex flow is established between adjacent trays
Implementation Method 3
a low energy vortex flow is established between adjacent trays. The low energy vortex allows grit particles entrained by the flow to settle on the sloping inner surface of each tray
Data Source
AI summary
A separator 2 for separating solids, such as grit, from an influent, such as water, the tray assembly 4 comprising a plurality of nested tray units 14 which are spaced apart from one another along a vertical separator axis 16. Each tray unit 14 comprises a substantially conical tray 18, an aperture 20 in the apex of the tray 18, and a means for restricting flow through the respective aperture 20, such as a baffle 22 disposed at or adjacent the aperture 20. In use, grit is separated from water circulating among the trays 18 and falls through successive apertures 20 in each of the trays to exit through the bottom of the tray assembly 4. The baffles 22 restrict upward flow through the apertures 20 in the trays 18 thereby reducing agitation of the grit.