How a Fuel Cell Humidifier Safely Mixes Exhaust Gases
Hyundai's patent describes a fuel cell humidifier that not only adds moisture to incoming air but also intelligently mixes exhaust gases, including hydrogen, with fresh air using a special valve to make the exhaust safer before it leaves the system.
Original patent title: “Humidifier for fuel cell”
Hyundai's patent describes a fuel cell humidifier that not only adds moisture to incoming air but also intelligently mixes exhaust gases, including hydrogen, with fresh air using a special valve to make the exhaust safer before it leaves the system. Owned by Hyundai Motor with 15 claims and 6 forward citations, and it is expected to expire in 2039.
Coverage
What does this patent actually cover?
This humidifier prepares air for a fuel cell by passing "supply air" through a "humidifying membrane" (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1), which adds moisture. The humidified air then goes to the fuel cell's cathode. Crucially, the system includes a "first valve" (Claim 1) that can selectively connect the fresh air path with the exhaust gas path. This valve opens automatically when the "internal pressure of the second region" (Claim 2), where exhaust gas flows, reaches a certain level. When open, fresh "supply air" mixes with the "exhaust gas" (Claim 1) from the fuel cell, including "exhaust hydrogen" (Claim 2). This mixing reduces the "hydrogen concentration" (Claim 2) in the gas discharged to the exhaust system, enhancing safety. For example, if a fuel cell vehicle produces hydrogen-rich exhaust, this system can dilute it with fresh air before release.
The gap
What does this patent NOT cover?
- Humidifiers that do not include a valve for selective communication between the supply air region and the exhaust gas region (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Systems where the valve does not open due to the internal pressure of the exhaust gas region (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 2).
- Humidifiers that do not mix supply air with exhaust gas to specifically reduce hydrogen concentration (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 2).
- Humidifiers lacking a separate, pressure-operated valve for exhaust hydrogen introduced from the fuel cell anode (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 10).
- Humidifiers where the first valve is not installed between the first cap and the exhaust gas outlet (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 3).
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The core innovation is the "first valve" (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1) that provides selective communication between the fresh air supply and the exhaust gas path. This valve is designed to open automatically based on exhaust gas pressure (Claim 2), enabling the system to actively mix fresh air with exhaust to reduce hazardous hydrogen concentrations before discharge.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Hyundai NEXO fuel cell electric vehicle
Toyota Mirai fuel cell electric vehicle
Stationary fuel cell power generators
Hydrogen-powered buses
Why it matters
The bigger picture
Fuel cells require humidified air to operate efficiently and prevent their internal membranes from drying out. Beyond efficiency, managing exhaust gases, particularly hydrogen, is vital for safety in fuel cell applications like vehicles. This patent addresses both the performance need for humidification and the critical safety requirement of diluting potentially flammable hydrogen in the exhaust stream.
Filed
September 13, 2019
Market context
Who's building on this
Companies in this space
Hyundai Motor, as the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is a major developer of fuel cell technology, particularly for fuel cell electric vehicles (FCEVs) like the NEXO. Other automotive companies such as Toyota and Honda, along with specialized fuel cell system manufacturers like Ballard Power Systems and Plug Power, are also actively developing and refining similar humidifier and exhaust management technologies for their fuel cell products.
Market impact
This type of technology enhances the safety and efficiency of fuel cell systems, which is crucial for their broader adoption, especially in passenger vehicles and other consumer-facing applications. By providing a mechanism to actively manage and dilute hydrogen in exhaust, it helps address a significant safety concern, thereby supporting consumer acceptance and facilitating regulatory approvals for fuel cell products, contributing to the growth of the FCEV market.
Claim 1 — Plain English
What this patent covers
This humidifier prepares air for a fuel cell by passing "supply air" through a "humidifying membrane" (Claim 1), which adds moisture. The humidified air then goes to the fuel cell's cathode. Crucially, the system includes a "first valve" (Claim 1) that can selectively connect the fresh air path with the exhaust gas path. This valve opens automatically when the "internal pressure of the second region" (Claim 2), where exhaust gas flows, reaches a certain level. When open, fresh "supply air" mixes with the "exhaust gas" (Claim 1) from the fuel cell, including "exhaust hydrogen" (Claim 2). This mixing reduces the "hydrogen concentration" (Claim 2) in the gas discharged to the exhaust system, enhancing safety. For example, if a fuel cell vehicle produces hydrogen-rich exhaust, this system can dilute it with fresh air before release.
The clever bit
The core innovation is the "first valve" (Claim 1) that provides selective communication between the fresh air supply and the exhaust gas path. This valve is designed to open automatically based on exhaust gas pressure (Claim 2), enabling the system to actively mix fresh air with exhaust to reduce hazardous hydrogen concentrations before discharge.
What it does not cover
- Humidifiers that do not include a valve for selective communication between the supply air region and the exhaust gas region (Claim 1).
- Systems where the valve does not open due to the internal pressure of the exhaust gas region (Claim 2).
- Humidifiers that do not mix supply air with exhaust gas to specifically reduce hydrogen concentration (Claim 2).
- Humidifiers lacking a separate, pressure-operated valve for exhaust hydrogen introduced from the fuel cell anode (Claim 10).
- Humidifiers where the first valve is not installed between the first cap and the exhaust gas outlet (Claim 3).
Patent timeline
Application submitted to the patent office
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
17/40
Early citations
Claim breadth
10/20
Broad claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$67K – $215K
Midpoint $134K · 12.9 yr remaining · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
15 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Kim, J. S. How a Fuel Cell Humidifier Safely Mixes Exhaust Gases (U.S. Patent No. 20,200,266,464). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/20200266464/humidifier-for-fuel-cell-20200266464
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How a Fuel Cell Humidifier Safely Mixes Exhaust Gases cover?
Hyundai's patent describes a fuel cell humidifier that not only adds moisture to incoming air but also intelligently mixes exhaust gases, including hydrogen, with fresh air using a special valve to make the exhaust safer before it leaves the system.
Who owns patent US 20200266464?
This patent is owned by Hyundai Motor.
When does this patent expire?
This patent is expected to expire on September 13, 2039, when the invention enters the public domain.
What is patent US 20200266464 cited by?
This patent has been cited by 6 later patents that build on its ideas.
What problem does this patent solve?
Fuel cells require humidified air to operate efficiently and prevent their internal membranes from drying out. Beyond efficiency, managing exhaust gases, particularly hydrogen, is vital for safety in fuel cell applications like vehicles. This patent addresses both the performance need for humidification and the critical safety requirement of diluting potentially flammable hydrogen in the exhaust stream.
What does this patent NOT cover?
Humidifiers that do not include a valve for selective communication between the supply air region and the exhaust gas region (Claim 1).
Same assignee
More from Hyundai Motor
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