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#51 2021-07-18 12:28:29

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,297

Re: Practical Water Extraction Methods for Starship Missions

In contrast to the grand vision offered by Void in Post #50, what I am planning for this post must seem modest.

It might even quality as pedestrian, in comparison.

The purpose of ** this ** post is to describe an experiment that might be performed on Earth, by persons of modest means, to see if unclean (or undrinkable) water might be made drinkable through a modification of the MIT passive energy design reported by SpaceNut in the not-too-distant past in the forum.

For SpaceNut ... as you read this, please consider if you think it might be achievable within your budget and time constraints. You have already demonstrated mechanical skills far in excess of what I ** think ** is required for this demonstration.

The objection you raised, to the difficulty of using the original MIT design in a cold, frozen environment such as the East coast of the US in winter, has been playing on my mind.  The design I am about to offer ** should ** meet the winter challenge.

It ** should ** also work in summer, during rainy weather, or at any other climate condition I can think of, short of earthquake or firestorm.

Start with the basic MIT idea .... this consists (as I understand it) of a clear window (glass or plastic) enclosing a sealed volume with a pan of (dirty) water in the bottom.  To allow the system to operate with least possible maintenance, some modest mechanical filtering of the incoming water would make sense. An example of such a filter would be sand through which the incoming water would percolate at a rate matched to the production rate of the distiller.

Sunlight would be admitted to the volume through the window as in the MIT design.  However, from ** there **, I offer the following amendments:

1) Using components of an old but still working refrigerator...

  a. Install the cooling coils above a metal back plate arranged at an angle over the water bath, so that distilled water is drawn by gravity into a trough for egress to a collection container.

b. Install the heat exchanger under the water bath so that heat extracted from the cooling plate is fed into the water bath.

Thus, the solar input would be supplemented by the thermal energy moved by the mechanical system.

In addition, the default cooling to atmosphere of the MIT design (as I understand it) would be supplemented by the mechanical thermal movement of the mechanical system.

The system would be constructed with sensors to accurately measure the operating conditions of the experiment, to deliver useful information for evaluation.

The energy input to the system would consist of electrical energy that can be measured by inexpensive devices, and by solar energy that can be measured indirectly by another set of inexpensive devices (small solar cells designed for the purpose).

The water flowing into the system should match that coming out, less solids that are left in the heating tray.

The solids in the heating tray would include iron atoms (in the case of SpaceNut's situation) and other atom types in other situations.

The water flowing out of the system would consist of water molecules and molecules light enough to be launched into the air by thermal energy. For that reason, the water would not be pure H2O, but it ** should ** be potable.

I'm hoping there may be suggestions forthcoming from members with posting privileges for further separation of water molecules from any other molecules that may be present in the distillate.

***
2. This topic is written with the qualification "for Starship missions".

it seems conceivable to me that the method(s) of water purification described here might be applicable to space craft where gravity is present, such as the Large Ship.  Gravity is needed to provide a way for molecules liberated from the warming tray by thermal energy to flow to a collection point on the cooling surface. 

The suggestion of OF1939, for scraping of the water collection surface also has merit, although it does increase the complexity of the system modestly.

(th)

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#52 2021-07-18 13:07:44

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,078

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#53 2021-07-18 13:26:36

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,297

Re: Practical Water Extraction Methods for Starship Missions

For SpaceNut re #52

SearchTerm:books on distillation of water for survival or regular home use
SearchTerm:distill water for survival or regular home use

I'm leaning toward adding the book you linked to my budget for next month.  It looks like a helpful guide to have on the shelf.

***
One of the links mentioned that alcohol is one of the molecules that is light enough to lift up with water molecules in the heated pan.

There is a TV cable show about American distillers (moonshiners) that illustrates practical application of this principle of physics. 

The fact that aromatic carbon molecules are light enough to join water molecules in escape is evident when a cook sets a pot on the stove to simmer.  The house (or habitat) fills up with the (hopefully pleasant) aroma of whatever is in the pot.

However, water from a swamp is unlikely to be generate pleasant aromas.

That is where the recommendation of OF1939 for activated charcoal might seem helpful.  However, my experience does not include working with activated charcoal, except as a consumer using disposable items.  For a regular water purification system, it would be nice to have a self-cleaning subsystem to detect and remove any molecules that contain carbon.

This is the province of nanotechnology.  Activated charcoal is a good example of nanotechnology at work in bulk form.  I'm interested in dynamic nanotechnology that completes the full cycle, from detecting and capturing the unwanted molecule, to routing it to an exit point for removal.

The alternative is to be able to identify, capture and remove water molecules, but the ideal would be to do both at once, so the volume of the distiller does not load up with aromatic carbon molecules.

(th)

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#54 2021-07-18 13:32:59

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,078

Re: Practical Water Extraction Methods for Starship Missions

Passing tap water or other through the activated charcoal filters like Britter or others are commonly used where water is a problem for metals and other such nasty aspects of taste.

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#55 2021-07-18 16:20:54

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,297

Re: Practical Water Extraction Methods for Starship Missions

For SpaceNut re #54

Your mention of activated charcoal is interesting, and it stimulated the question... how does activated charcoal work?

It appears that more than a few folks have had the same question:

Per Google:

Activated charcoal works by trapping toxins and chemicals in the gut, preventing their absorption ( 2 ). The charcoal's porous texture has a negative electrical charge, which causes it to attract positively charged molecules, such as toxins and gases. This helps it trap toxins and chemicals in the gut ( 2 , 3).Jun 29, 2017

What Is Activated Charcoal Good For? Benefits and Uses
https://www.healthline.com
About featured snippets

Feedback

Debunking the Hype Surrounding Activated Charcoal ...
https://integrisok.com
Dec 3, 2019 — How does activated charcoal work? ... Activated charcoal binds to toxins and chemicals to keep your body from absorbing them. Adsorption occurs ...

The Truth About Activated Charcoal: How and When It Works
https://www.webmd.com
Dec 21, 2019 — How It Works ... The charcoal is “activated” when it's heated to a very high temperature. This changes its structure. Heating gives the fine ...

Activated charcoal: 8 uses and what the science says
https://www.medicalnewstoday.com
Superheating natural sources of carbon, such as wood, produces activated charcoal. The black powder stops toxins from being absorbed in the stomach by binding ...
What is activated charcoal? · Possible uses · Medical uses · Risks and takeaway

Activated Charcoal: The Powerful Detox Ingredient You Don't ...
https://www.goodrx.com
Feb 7, 2019 — So, the sooner activated charcoal is taken after swallowing the drug or poison, the better it works—generally within 30 to 60 minutes. The toxic ...

10 Ways To Use Activated Charcoal For Health And Beauty ...
https://www.chiropractor-schaumburg.com
Working to eliminate toxins and chemicals that linger in our bodies, taking a few capsules of activated charcoal per day can flush your system. (3) This can ...

Activated charcoal benefits and how to use the product safely
https://www.singlecare.com
Feb 27, 2020 — Activated charcoal works through the digestive tract by trapping toxins in the gut and preventing them from being absorbed. Activated charcoal ...

Activated charcoal works by trapping toxins and chemicals in the gut, preventing their absorption ( 2 ). The charcoal's porous texture has a negative electrical charge, which causes it to attract positively charged molecules, such as toxins and gases. This helps it trap toxins and chemicals in the gut ( 2 , 3).Jun 29, 2017

What Is Activated Charcoal Good For? Benefits and Uses
https://www.healthline.com
About featured snippets

Feedback

Debunking the Hype Surrounding Activated Charcoal ...
https://integrisok.com
Dec 3, 2019 — How does activated charcoal work? ... Activated charcoal binds to toxins and chemicals to keep your body from absorbing them. Adsorption occurs ...

The Truth About Activated Charcoal: How and When It Works
https://www.webmd.com
Dec 21, 2019 — How It Works ... The charcoal is “activated” when it's heated to a very high temperature. This changes its structure. Heating gives the fine ...

Activated charcoal: 8 uses and what the science says
https://www.medicalnewstoday.com
Superheating natural sources of carbon, such as wood, produces activated charcoal. The black powder stops toxins from being absorbed in the stomach by binding ...
What is activated charcoal? · Possible uses · Medical uses · Risks and takeaway

Activated Charcoal: The Powerful Detox Ingredient You Don't ...
https://www.goodrx.com
Feb 7, 2019 — So, the sooner activated charcoal is taken after swallowing the drug or poison, the better it works—generally within 30 to 60 minutes. The toxic ...

10 Ways To Use Activated Charcoal For Health And Beauty ...
https://www.chiropractor-schaumburg.com
Working to eliminate toxins and chemicals that linger in our bodies, taking a few capsules of activated charcoal per day can flush your system. (3) This can ...

Activated charcoal benefits and how to use the product safely
https://www.singlecare.com
Feb 27, 2020 — Activated charcoal works through the digestive tract by trapping toxins in the gut and preventing them from being absorbed. Activated charcoal ...

I deduce that if you were to plan to use activated charcoal to remove non-water molecules from a vapor in a solar still, you would need to plan to heat the material periodically to drive off the trapped molecules.

That would certainly appear to be a way to accomplish the task.

However, what I'm looking for is a solution that operates at the nanotechnology level (as activated charcoal certainly does) but with the wrinkle that the trapped molecules are transported to a collection point continuously, so the active component does not hold onto the trapped molecules.

Thanks again for adding to the topic.

(th)

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#56 2021-09-09 11:22:38

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 884

Re: Practical Water Extraction Methods for Starship Missions

Safeguarding clean water for spaceflight missions
https://www.spacedaily.com/reports/Safe … s_999.html

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