Researchers Create Air Filter Designed to Trap and Kill the Coronavirus

Nickel Foam Filter is Designed to Catch, Heat and Kill the Virus and other Pathogens

By Jeannie Kever 713-743-0778

July 14, 2020


Researchers from the University of Houston, in collaboration with others, have designed a “catch and kill” air filter that can trap the virus responsible for COVID-19, killing it instantly.

Zhifeng Ren, director of the Texas Center for Superconductivity at UH, collaborated with Monzer Hourani, CEO of Medistar, a Houston-based medical real estate development firm, and other researchers to design the filter, which is described in a paper published in Materials Today Physics.

The researchers reported that virus tests at the Galveston National Laboratory found 99.8% of the novel SARS-CoV-2, the virus that causes COVID-19, was killed in a single pass through a filter made from commercially available nickel foam heated to 200 degrees Centigrade, or about 392 degrees Fahrenheit. It also killed 99.9% of the anthrax spores in testing at the national lab, which is run by the University of Texas Medical Branch.

“This filter could be useful in airports and in airplanes, in office buildings, schools and cruise ships to stop the spread of COVID-19,” said Ren, MD Anderson Chair Professor of Physics at UH and co-corresponding author for the paper. “Its ability to help control the spread of the virus could be very useful for society.” Medistar executives are is also proposing a desk-top model, capable of purifying the air in an office worker’s immediate surroundings, he said.

Ren said the Texas Center for Superconductivity at the University of Houston (TcSUH) was approached by Medistar on March 31, as the pandemic was spreading throughout the United States, for help in developing the concept of a virus-trapping air filter.

Luo Yu of the UH Department of Physics and TcSUH along with Dr. Garrett K. Peel of Medistar and Dr. Faisal Cheema at the UH College of Medicine are co-first authors on the paper.

The researchers knew the virus can remain in the air for about three hours, meaning a filter that could remove it quickly was a viable plan. With businesses reopening, controlling the spread in air conditioned spaces was urgent.

And Medistar knew the virus can’t survive temperatures above 70 degrees Centigrade, about 158 degrees Fahrenheit, so the researchers decided to use a heated filter. By making the filter temperature far hotter – about 200 C – they were able to kill the virus almost instantly.

Ren suggested using nickel foam, saying it met several key requirements: It is porous, allowing the flow of air, and electrically conductive, which allowed it to be heated. It is also flexible.

But nickel foam has low resistivity, making it difficult to raise the temperature high enough to quickly kill the virus. The researchers solved that problem by folding the foam, connecting multiple compartments with electrical wires to increase the resistance high enough to raise the temperature as high as 250 degrees C.

By making the filter electrically heated, rather than heating it from an external source, the researchers said they minimized the amount of heat that escaped from the filter, allowing air conditioning to function with minimal strain.

A prototype was built by a local workshop and first tested at Ren’s lab for the relationship between voltage/current and temperature; it then went to the Galveston lab to be tested for its ability to kill the virus. Ren said it satisfies the requirements for conventional heating, ventilation and air conditioning (HVAC) systems.

“This novel biodefense indoor air protection technology offers the first-in-line prevention against environmentally mediated transmission of airborne SARS-CoV-2 and will be on the forefront of technologies available to combat the current pandemic and any future airborne biothreats in indoor environments," Cheema said.

Hourani and Peel have called for a phased roll-out of the device, “beginning with high-priority venues, where essential workers are at elevated risk of exposure (particularly schools, hospitals and health care facilities, as well as public transit environs such as airplanes).”

That will both improve safety for frontline workers in essential industries and allow nonessential workers to return to public work spaces, they said.

 

Simple, direct, done.

 

It sounds promising, especially as the pathogen is considered airborne. Droplet spray has a relatively short range, but some of the viral load has the capacity to piggyback on dust motes for some time. Thiis airfilter system would be useful for scrubbing and destroying pathogens that are airborne...not just Covid 19.

Undoubtedly industrial and commercial systems are likely to be developed initially, but there may be scope for developning domestic systems...which on a large scale is likely to reduce the unit price.

 

It does look promising for some applications, say like clean rooms. As a general volume treatment, open to the courtyard (so to say) I have some doubts, mostly due to expense. Worth watching.

 

Not as I read it.
"By making the filter electrically heated, rather than heating it from an external source, the researchers said they minimized the amount of heat that escaped from the filter, allowing air conditioning to function with minimal strain.

A prototype was built by a local workshop and first tested at Ren’s lab for the relationship between voltage/current and temperature; it then went to the Galveston lab to be tested for its ability to kill the virus. Ren said it satisfies the requirements for conventional heating, ventilation and air conditioning (HVAC) systems."

This would mean tip over shut off and high temp shut off and what ever was in the code for fixed or portable units.

 

@$400 I'd be a buyer, after all I have a super good UV C unit with Hepa Filters for half that much.

 

I know people that could use a ''step-in'' model...Might need a spark arrestor on the discharge side?

 

The heat is contained due to the insulation and the low air flow volume.

We used electrostatic participators in the Navy to keep our air clean, don't get me wrong it is not the same Technology but it may be one of the reasons our Subs are able to operate in a safer manner than surface ships. Just sayin.
An electrostatic precipitator (ESP) is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit.
Electrostatic precipitator - Wikipedia

 

Yup I was on on one those old boats.

 

I think the main concern is for enclosed spaces where people tend to congregate and the virus rides the convection currents in the room / building. Rooms which are open to the weather where the wind and weather would dilute the concentration of pathogens would be much less of a concern, though masking and social distancing would still be prudent precutions in limiting pathogen spread..

Most modern portable electrical heating appliances have, as @HK_User points out, 'tip-over' and other safety features which will kill the current to the appliance. However yes, there may be some risk involved as there is with any electrical device, if not properly maintained or if operated contrary to the device's operating / safety instructions. Benefits would have to be evaluated against risks.

I realise that it was suggested as a droll commentary on some of your associates, however the notion is not completely absurd.

I think that a good showering with a liberal application of soap / hair shampoo would be adequate for decontamination, as well as stripping off and laundering clothes that were worn in the 'hot zone' before entering the safe zone of one's dwelling. Keeping footwear worn outside of one's home separate from footwear worn inside the home would also be a good idea. One option might be to adapt a laundry with internal and external access to the home for additional use as a mud room / decontamination room. What is Mud Room? 7 Design Ideas

 

Was that the Monitor or the Merrimack??

 

Those were the two oldest I could remember SM
Capt. MAY have influenced the aforementioned post?

 

You see this Ghrit? SM is calling you old...

 

You're a braver, (or more foolhardy) man than I, SM....hope your medical insurance is up to date.