Negative Pressure Envelop for Controlled Environment Rooms
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Solution Overview
Problem
Existing insulated and controlled environment rooms face challenges in achieving effective two-way isolation, as air leakage can occur both into and out of these rooms, compromising the integrity of the environment and potentially allowing contaminants to escape or enter.
Innovation Solution
The implementation of a Negative Pressure Envelope (NPE) surrounding the insulated room, which maintains air pressure substantially lower than both the atmosphere and the room's internal pressure, effectively captures and filters any leaking air, preventing contamination from entering or leaving the room.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If positive pressure is maintained in the clean room to prevent contaminated air infiltration from outside, then air leakage from outside into the room is prevented, but air leakage from inside the room to outside cannot be controlled
Solution Approach 1:
The wall structure is segmented into multiple layers including an outer wall, insulation layer, and inner wall, creating distinct pressure zones. The NPE is formed in the insulation space between these layers, allowing independent pressure control to address both infiltration and effluent air issues simultaneously.
Solution Approach 2:
The NPE acts as an intermediary pressure zone between the clean room and the external environment. By maintaining negative pressure in this intermediate layer, it captures both incoming contaminated air and outgoing effluent air, preventing both infiltration and uncontrolled discharge.
2Object-generated harmful factors
If the room is kept at negative pressure to prevent effluent air leakage to surroundings, then air leakage from inside to outside is prevented, but contaminated air infiltration from outside cannot be prevented
Solution Approach 1:
The wall structure is segmented into multiple layers including an outer wall, insulation layer, and inner wall, creating distinct pressure zones. The NPE is formed in the insulation space between these layers, allowing independent pressure control to address both infiltration and effluent air issues simultaneously.
Solution Approach 2:
The NPE acts as an intermediary pressure zone between the clean room and the external environment. By maintaining negative pressure in this intermediate layer, it captures both incoming contaminated air and outgoing effluent air, preventing both infiltration and uncontrolled discharge.
3Reliability
If sealing means are installed at wire and cable crossing points to maintain room integrity, then air leakage through walls is reduced, but these sealing means are prone to failure due to wear and mishandling
Solution Approach 1:
The sealing function is extracted from the wall structure itself and transferred to the NPE system. Instead of relying on seals at penetration points, the negative pressure envelope captures any air that leaks through these points, making the sealing requirements less critical and more reliable.
Solution Approach 2:
The NPE creates a virtual seal through pressure differential rather than physical sealing at each penetration point. This pressure-based sealing approach is more reliable as it doesn't depend on the condition of physical seals that can wear or fail.
4Object-affected harmful factors
If the room is designed as airtight to prevent air infiltration, then contaminated air entry is minimized, but achieving complete airtightness is difficult due to cracks and tiny holes in walls and ceilings
Solution Approach 1:
The sealing function is extracted from the wall structure itself and transferred to the NPE system. Instead of relying on seals at penetration points, the negative pressure envelope captures any air that leaks through these points, making the sealing requirements less critical and more reliable.
Solution Approach 2:
The NPE creates a virtual seal through pressure differential rather than physical sealing at each penetration point. This pressure-based sealing approach is more reliable as it doesn't depend on the condition of physical seals that can wear or fail.
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 NPE system ensures that any air leakage is directed into the low-pressure envelope, where it can be filtered and exhausted, thereby maintaining the room's internal environment and preventing the escape or infiltration of contaminants.
Implementation Method 1
the air pressure inside the NPE is maintained at some given value, appreciably below atmospheric pressure and the pressure inside the insulated room. As a result, any air that leaks from the surroundings through an outer panel or wall into the NPE will not proceed through the inner panel to infiltrate the insulated room, because of the higher pressure prevailing there
Implementation Method 2
any air that leaks from the insulated room through the inner panel into the NPE will not proceed through the outer panel or wall to the surrounding spaces. Thus all contaminants-whether from the surroundings or from inside the insulated room-that leak through the respective walls, floor or ceiling will automatically be captured in the low-pressure NPE space and may be filtered out by a suitable filter
Data Source
AI summary
A room insulation system, for preventing leakage of contaminants from an insulated room to its surroundings and/or from the surroundings into the insulated room, the insulated room being enclosed by any of a floor, a ceiling and one or more walls, the system comprising—an inner panel, disposed parallel to, and a given distance from, a corresponding floor, ceiling or wall, forming an insulation space between them, andan air extraction system, including a fan and a filter;wherein the insulation spaces are fluidly interconnected, to form a Negative Pressure Envelope (NPE),the intake port of the air extraction subsystem is fluidly connected to the NPE and the exhaust port of the air extraction subsystem is fluidly connected to the atmosphere andwherein the air extraction subsystem is configured and operative to extract air from the NPE into the atmosphere while maintaining an air pressure within the NPE substantially below the atmospheric pressure and the air pressure within the insulated room.