Water sieve thermodynamics? (Or: sieving ph2o with hot regolith)

[myxal]

Apologies if this was discussed (the forum's search isn't great, google finds me only results from the days when water sieve was temperature-clamped, and the wiki doesn't mention this on the water sieve or the regolith page).

Can someone give me a run-down of heat flow of a water sieve? I'm thinking of using it in space biome (base game), denying dupe access and using only shipping-delivered regolith to filter the water.

In particular:

• Is the heat (produced by the machine) deposited into the output, the cell(s) of interest, or will I need the usual space biome cooling? (ie. layer of liquid on the floor, or drywall-backed, gas-filled room and a piped medium to carry the heat away)
• What happens to the hot regolith? Is the polluted dirt spit out at the same temperature as the delivered regolith, or are the temps. equalised between p.water and regolith before the transformation? (Will the sieve spit the water out hotter than what it took?)

 

[Neotuck]

Without checking, It's my understanding that materials (p-water and regolith) that are stored within the sieve will exchange temp with it but I don't know at what rate.

However I do know that the sieve can only hold 20kg p-water and 1200kg regolith so it's unlikely the incoming liquid will be enough to cool the hot regolith

Additionally if you are planning on using an auto-sweeper in a vacuum to load the sieve, those WILL overheat

[myxal]

1 hour ago, Neotuck said:

materials (p-water and regolith) that are stored within the sieve

Damn, at those masses the heat capacity ratio is ~2.86 in regolith's favour, ie for every °C the regolith cools down the water heats up 2.86°C, so for 30°C water to output < 100°C the regolith should be no more than 124°C, oof..) I wonder if this heat transfer is facilitated by CoI not being in vacuum, and could simply be avoided (flood the machine as usual, then remove drywall behind CoI)

 

1 hour ago, Neotuck said:

Additionally if you are planning on using an auto-sweeper in a vacuum to load the sieve those WILL overheat in a vacuum

Yeah, already aware of that - i'm thinking of building something like this.

The initial batch of regolith will need a bit of manually-managed cooling, perhaps running the conveyor rail through U-shaped arrangement of metal tiles with a polluted ice tempshift plate in the middle?

Crucially, I wonder about the supply logistics of water sieve - when does it request more filtration medium? The larger the batch, the more annoying it will be to cool it. Perhaps a metal tile under a liquid reservoir which I need to keep sufficiently full? 

[Neotuck]

56 minutes ago, myxal said:

The initial batch of regolith will need a bit of manually-managed cooling, perhaps running the conveyor rail through U-shaped arrangement of metal tiles with a polluted ice tempshift plate in the middle?

Perhaps setting up a steam turbine to delete heat from the regolith?  Conveyor rail though metal tiles that heat up the steam?

[myxal]

15 hours ago, Neotuck said:

Perhaps setting up a steam turbine to delete heat from the regolith?  Conveyor rail though metal tiles that heat up the steam?

Steam turbine would be overkill, at least for me - I'm running a heat harvesting loop through my bunker doors/tiles, so my regolith is already down to ~220°C

Checking the math:

• polluted ice tempshift plate: 800 kg x 4.179 (SHC) x 117 (temp. delta between highest build temperature -17°C and 100°C) = 285 MDTU
• 8 copper metal tiles: 700kg x 0.385 * 55 = 14.8 MDTU

This much heat capacity can cool down almost 6 tonnes of 350°C regolith to 100°C, or almost 10 tonnes of 250°C regolith.. Hell, I might skip the rail system (too fiddly not to "overchill" the initial run of regolith) and just build a storage container in a trough made of metal tiles.

 

[Neotuck]

4 hours ago, myxal said:

Steam turbine would be overkill

I agree they are overkill which is why I like to build them with multiple uses in mind

[blakemw]

You can safely use hot regoloth with cool pwater. The temperature increase is very little.

Cool the water sieve using a puddle in just one corner only, that way the hot regolith inside the sieve is not sitting in the puddle of liquid and will not exchange heat (until combined with pwater). Same goes with the Conveyor Loader, have the non-arrow tile in the liquid, and the arrow tile in vacuum so the regolith doesn't exchange heat. It is good practice whenever buildings are holding hot stuff, to have the actual location of the hot stuff in vacuum, just less problems.

 

[Jann5s]

Or, boil the pwater with the regolith and get sand free sieving

[myxal]

12 hours ago, blakemw said:

Same goes with the Conveyor Loader, have the non-arrow tile in the liquid, and the arrow tile in vacuum so the regolith doesn't exchange heat.

The loader would be used for (polluted) dirt - would that be hot coming out of the sieve to cause problems? But yeah, good point, put cell of interest in vacuum.

 

12 hours ago, Jann5s said:

Or, boil the pwater with the regolith and get sand free sieving

I actually have a similar setup - boiling ph2o (map spawn, cool-slush-powered base cooling loop discharge, and cool slush directly feeding into it). I don't feed bathroom water into it (yet) - too worried it might not cool down sufficiently, and I'm NOT replacing all bathroom plumbing with insulated pipes...

Thing is, though - I'd actually like to get more dirt and polluted dirt. I'm below 100t on the first one (and have yet to build a pip ranch) and I'm worried my plastic dreko ranch might not produce enough plastic eggs on bristle berries alone. And having polluted dirt to sustain a bigger, maintenance-free population of pokeshells is always a plus. (More lime ingredients -> MOAR STEEL!)