China builds ‘world’s biggest air purifier’ and it seems to be working • Hacker News Board

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#71

Post by seanmcdirmid » Tue, Jan 16, 2018, 7:19 PM UTC

darethas wrote: post #67

seanmcdirmid wrote: post #46

Earlier quoted context omitted.

Trees can help with carbon, but we are talking about small particles here. I guess they could trap them or something, but not on the scale of a typical polluted day in say Beijing. Anyways, in northern china, this wouldn’t be very workable as the pollution season corresponds to leafless tree season (and the trees turn a dreary brownish grey due to dust).

Correct my understanding here where I am wrong - In my mind, if a leaf of a tree or any vegetation photosynthesizes, it is pulling in air (dirty air by your account which is why those leaves are brown) By the very virtue of that fact, it would be pulling in those small particles as well. The paper I referenced states that this happens to an extent, which is why trees during the leafy season are more effective at redu…

You are probably right, but a better solution would be to create breeze ways that would allow wind to blow out the pollution more easily. These could be coupled with forests, of course. These cities have plenty of trees, but they aren’t newrly enough and anyways winter is the worst season.

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#72

Post by LeifCarrotson » Tue, Jan 16, 2018, 7:44 PM UTC

kragen wrote: post #56

LeifCarrotson wrote: post #37

Earlier quoted context omitted.

> many many tons of particulate matter every day Let's do the math. Guidelines state that the limit on PM2.5 particulates is approximately 10 micrograms per cubic meter for an annual average. Xian, where the tower was installed, is currently ( http://aqicn.org/city/xian/ ) under 231 ug/m^3 of pollution. The tower is supposed to process 10 million cubic meters of air per day. 10^7 m^3 x 231 x 10^-6 g/m^3 x 10^-3 g/kg…

0.35 kg of particulate contamination removed per day; you rounded incorrectly, but the rest of your math is right. There's the issue that it's probably removing nearly all of the particulates from the air it actually processes, say over 90%, which works out to 2.1 kg. It doesn't reduce the PM2.5 level in the area by 90%, but only by 15%, because it's only able to process some 16% of the air in its area during whateve…

Thanks for verifying my result and catching my mistake. You're right, it's a volume of 10 x 10⁸ cubic meters, which is 10⁹.

That's what I get for interweaving a mantissa of 10 with scientific notation! Too late to edit now, but people should see this comment thread.

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#73

Post by fenwick67 » Tue, Jan 16, 2018, 9:39 PM UTC

Something1234 wrote: post #25

pcx wrote: post #23

Earlier quoted context omitted.

Isn't AMP open source? How is it bad, and an abuse by Google?

I believe that it routes them into a proprietary cache by google. Taking page views from the provider or at least that is my understanding of it.

I can't speak for everyone, but my objection to the AMP cache is that it's just another way for Google to collect your browsing data.

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#74

Post by sangnoir » Tue, Jan 16, 2018, 10:15 PM UTC

quadcore wrote: post #10

Side node: is China doing ok in terms of innovation? If yes, how come in such a regime? I would expect everything to be stuck in bureaucracy.

> Side node: is China doing ok in terms of innovation?

Despite that the HN consensus saying otherwise - I'll say yes, China is innovating just fine. Just a few days back, I got downvoted for stating that DJI was forcing competitors to exit the drone market by out-innovating them.

> If yes, how come in such a regime?

Perhaps because innovation and governance model aren't as coupled as some would assume/like?

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#75

Post by Robotbeat » Tue, Jan 16, 2018, 11:23 PM UTC

quadcore wrote: post #10

Side node: is China doing ok in terms of innovation? If yes, how come in such a regime? I would expect everything to be stuck in bureaucracy.

Perhaps by having 5 times the population of the US, they can accomplish quite a lot even if the authoritarianism hinders innovation.

More brains, more dreams, more ideas.

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#76

Post by AstralStorm » Wed, Jan 17, 2018, 9:24 AM UTC

kragen wrote: post #56

LeifCarrotson wrote: post #37

Earlier quoted context omitted.

> many many tons of particulate matter every day Let's do the math. Guidelines state that the limit on PM2.5 particulates is approximately 10 micrograms per cubic meter for an annual average. Xian, where the tower was installed, is currently ( http://aqicn.org/city/xian/ ) under 231 ug/m^3 of pollution. The tower is supposed to process 10 million cubic meters of air per day. 10^7 m^3 x 231 x 10^-6 g/m^3 x 10^-3 g/kg…

0.35 kg of particulate contamination removed per day; you rounded incorrectly, but the rest of your math is right. There's the issue that it's probably removing nearly all of the particulates from the air it actually processes, say over 90%, which works out to 2.1 kg. It doesn't reduce the PM2.5 level in the area by 90%, but only by 15%, because it's only able to process some 16% of the air in its area during whateve…

Considering how a lot of China electricity is generated by coal plants, electroscrubbing the filters might not be the best way.

Three are alternative chemical processes to clean up such filters.

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#77

Post by chrismcb » Sat, Jan 20, 2018, 5:54 AM UTC

moron4hire wrote: post #51

captainmuon wrote: post #33

Earlier quoted context omitted.

Devil's advocate: Google is generous by caching AMP sites on their own servers. The only thing you can't do is to include your own invasive third party tracking (ok, you can use Google's of course), which is bad anyway. But you can still include your ad just as a in the page, no JS and tracking. Like a dumb print ad. I don't really have a problem with that.

There is no such thing as a generous corporation. It goes completely against maximizing shareholder value. Google gets something out of AMP, something they can quantify monetarily.

You do know that a corporation does not maximize shareholder value, nor is that their purpose. A company can do something generous. Sometimes something that helps the customer also helps the company.

Re: China builds ‘world’s biggest air purifier’ and it seems to be working

#78

Post by kragen » Tue, Jan 23, 2018, 12:48 AM UTC

nullbyte wrote: post #65

kragen wrote: post #56

Earlier quoted context omitted.

0.35 kg of particulate contamination removed per day; you rounded incorrectly, but the rest of your math is right. There's the issue that it's probably removing nearly all of the particulates from the air it actually processes, say over 90%, which works out to 2.1 kg. It doesn't reduce the PM2.5 level in the area by 90%, but only by 15%, because it's only able to process some 16% of the air in its area during whateve…

I love HN comment like this. Seems like there's an expert in everything here!

I am not an expert in air pollution control systems, or even an amateur. I don't even have an air filter installed in my house. I read some Wikipedia articles over the last couple of years, Googled, and watched some videos on YouTube (including "how-to" videos on the care and feeding of electronic air cleaners.) That doesn't make me an expert. That makes me some sort of approximation of a journalist — and if you've ever read those people writing about something you know about, you know how much they get wrong.