Drainage Stack Air Reservoir for Pressure Surge Attenuation
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Solution Overview
Problem
Existing solutions for suppressing and alleviating pressure transients in building drainage systems, particularly in high-rise buildings, are inadequate as they require additional space and extra junctions, and are not suitable for integration within the drainage stack, failing to effectively manage air pressure transients and negative reflections.
Innovation Solution
A positive air pressure attenuation device integrated within the main drainage stack, featuring an elastic flexible inflatable reservoir that can withstand high pressures and is designed to be part of the vertical drainage pipe, with a housing structure and openings that allow atmospheric air contact, enabling effective attenuation of both positive and negative pressure transients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing pressure attenuation devices are mounted adjacent to air admittance valves, then air pressure transients can be suppressed, but extra space and extra junctions are required
Solution Approach 1:
The patent combines the pressure attenuation function with the drainage stack itself by integrating a flexible reservoir directly into the stack structure. The reservoir is positioned within the stack and connected to the drainage pipe, eliminating the need for separate external devices and reducing installation complexity while maintaining pressure suppression effectiveness.
Solution Approach 2:
The flexible reservoir is nested within the drainage stack structure, with the reservoir chamber formed inside the stack walls. This nesting approach allows the pressure attenuation device to occupy space already allocated for the drainage system, avoiding additional space requirements and junctions that would be needed for external mounting.
2Reliability
If existing surge tanks are used, then pressure surges can be controlled, but they are not suitable for integration within the drainage stack and require parallel placement
Solution Approach 1:
The patent merges the surge control function with the drainage stack by forming the reservoir chamber within the stack structure itself. The stack walls enclose the reservoir chamber, and the drainage pipe passes through the stack to connect to the reservoir, creating an integrated system that provides both drainage and pressure surge control functions within a single structure.
Solution Approach 2:
The drainage stack is designed to serve multiple functions simultaneously: it acts as both the drainage conduit and the housing for the pressure attenuation reservoir. The stack structure provides structural support for the reservoir, defines the reservoir chamber boundaries, and facilitates the connection between the drainage pipe and reservoir, making the system adaptable to various building drainage configurations.
3Device complexity
If a flexible reservoir is integrated within the drainage stack, then space is saved and the device becomes compact, but the reservoir must withstand high positive air pressure transients
Solution Approach 1:
The patent employs a flexible reservoir made of elastomeric material that can expand and contract to accommodate pressure transients. The flexible nature of the reservoir allows it to withstand high positive air pressure by deforming elastically, while the elastomeric material provides the necessary strength and durability to handle repeated pressure cycles without failure.
Solution Approach 2:
The reservoir is designed with variable volume capability, allowing it to change its physical parameters (volume, shape) in response to pressure transients. During positive pressure events, the reservoir expands to absorb the pressure surge; during negative pressure events, it contracts. This dynamic parameter change enables the reservoir to withstand high pressures while maintaining a compact integrated design within the stack.
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 reduces air pressure transients by up to 90% and safely dissipates large air volumes, while being compact enough to be installed within the drainage stack, effectively managing pressure surges and reflections in high-rise buildings.
Implementation Method 1
an elastic flexible inflatable reservoir (8) associated to the inner central portion (6) of the pipe (3A), the reservoir (8) being operable on a positive air pressure transient within the drainage system (D)
Implementation Method 2
said plurality of openings (61) defining a total open surface such that the ratio total open surface of the openings (61) / total closed surface of the wall (60) is comprised from 1 : 100 to 1 : 4
Data Source
Figure 1
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AI summary
A positive air pressure attenuation device (1) comprising: - a housing (3) with an inner central portion (6) forming a channel (7); and an elastic flexible inflatable reservoir (8) associated to the inner central portion (6), whereby the inner central portion (6) has a wall portion (60) with a plurality of openings (61) forming passages between the channel (7) and the reservoir chamber (8A).