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newsDistiller DIY floor construction
The previous post, construction of the wood frame:
https://bkhome.org/news/201912/distiller-diy-assembling-the-frame.html
Now for the plywood floor. I decide to increase the thickness of the
floor insulation from 60mm to 66mm. This is a consequence of deciding
not to indent the glass into the wood, rather to just sit it on top,
with silicone foam strip between glass and wood frame. This gives a bit
more height under the glass at the front, so the floor can be raised a
bit.
I purchased marine plywood, 6mm thick, so marked out a height of 60mm
from the bottom of the distiller, for affixing framework to hold the
ply. I also put framework along the bottom, as it is intended to affix
6mm ply on the bottom of the distiller also.
As I had some 42x19mm pine, I cut it lengthwise into three strips
about 13mm wide each. This was done with the rotary saw. The strips were
then screwed to the distiller frame, using 6G 30mm screws, predrilled
with 2mm drill bit and 3.5mm into the top 19mm, and countersunk by hand
using a 7mm drill bit. This is what it looks like:
A straightforward operation, no need for detailed plans, anyone can
do this just by seeing this photo. One detail though: the back wall is
vertical, so no problem, however the front wall is 20 degrees off
vertical. Therefore, the strip of wood that I used along the front, I
cut with an angle of 20 degrees (my rotary saw has angle adjustment,
making that operation easy). This photo shows the strips looking from
the top, so that you can see the 20 degree cut on the front strip:
...the wide-angle lense on the phone distorts the image -- the back wall is actually vertical.
I cut the plywood with a handsaw, a tenon saw actually, 654x531mm,
with a slight angle to front, and it fitted in snuggly. I then used 6G
20mm screws, predrilled with a 2mm drill bit and countersunk by hand
with a 7mm drill bit.
| 6Gx20mm zinc-plated countersunk-head, 40pk |
AU$3.98 |
EDIT 2020-01-11:
The 6Gx20mm screws were purchased from Bunnings, Zenith zinc-plated
countersunk-head. Looking at Bunnings website now, can't see any
zinc-plated, but there are brass-plated:
https://www.bunnings.com.au/zenith-6g-x-20mm-brass-plated-hinge-long-threads-countersunk-head-timber-screws-40-pack_p2420082
...there are 6G 15mm zinc-plated, which would have enough reach.
Assembled view:
That was when I made an "interesting" discovery: While brushing wood
particles off the surface of the basin floor, tiny wood hairs lifted off
the surface of the plywood, and stuck up. I looked on the other side,
and the surface is more consolidated, wood hairs do not lift up.
This is a concern. Now that it is screwed in place, I really don't
want to lift it up and flip over. Besides, I chose that orientation as
the plywood sheet had a very slight bow -- only slight -- which I want
to to have the convex side on top. now that it is in place, it is very
flat.
I will probably give a fine sandpaper, but not if it is going to lift
up more hairs. Anyway, will try and get rid of the hairs, and hope that
when spreading the silicone sealant none of the hairs stand up.
EDIT 2020-01-11:
I used 120grit (fine) wood sandpaper on the plywood surface, and it took
off the wood "hairs". Looks good, ready for the sealant to be applied.
A construction detail that is not in the above photos: the distilled
water runoff pipe will be on the right side, coming out underneath in
the extreme right corner. So I left a gap in the floor support strips,
of about 15mm in the front right corner (as viewed standing in front of
the distiller). I could have cut out the corner of the plywood also,
however decided to drill it after the silicone has been spread.
There will also be inlet and drain holes.
Tags: nomad
Distiller DIY assembling the frame
I posted yesterday, the start of constructing the simple
basin-type solar water distiller, for which it is intended to publish
DIY plans:
https://bkhome.org/news/201912/start-of-diy-plans-for-solar-water-distiller.html
Today I cut the pieces for the wood frame, and screwed them together.
I mentioned yesterday that the frame could be cut with just a
handsaw. However, I mostly used a rotary (circular) saw, as this made it
easier to cut nice straight lines, and vertical cuts -- what I mean
about "vertical cuts" is when cutting the wood want the cut to be 90
degrees to the plane of the wood -- I have trouble with this with a hand
saw, usually end up with a slight slant to the right.
Of course, it would be nice to have a wood-working bench, but as I
only have a table, have to improvise. For example, this is the setup to
cut across the 235x19mm pine:
...three g-clamps were used, and the metal square is extremely
helpful. I quickly learnt exactly where to put the wood guide for the
rotary saw to cut along the desired line.
There were five pieces cut, and I put four of them together on the table prior to screwing:
...that is of course upside-down.
When constructing the previous prototype, I used some silicone
sealant to hold the corners in-place and left it to set overnight, then
screwed it the next day. I received an email from Rick about this:
With regards to holding the sides together for screwing. You could just use a block of wood, or even the thicker side of a set square, together with two clamps (G or sliding), align until satisfied and screw together. No waiting for silicone to dry.
Yes, I did one corner with two g-clamps, after that used just one clamp, like this:
...that provided enough alignment, and used one hand to press the corners together and the other hand to hold drill. Worked OK.
Regarding the insertion of the screws, I have watched those house
restoration shows on TV, where they just bung the screws in, no
pre-drilling. Well, I pre-drilled. I do this from prior experience with
MDF, that de-laminates very easily. Pine is much better, however as
screwing into the end of the wood, I decided to play-safe and pre-drill.
I used 6G 40mm countersunk zinc-plated wood screws. I firstly drilled
the full 40mm depth with a 2.5mm drill bit, followed by a 3.5mm drill
bit drilled only 19mm deep (I put a pen mark on the drill bit to get
this right). Finally, used a 7mm drill bit, held by hand, to gouge for
the countersunk head.
Todays shopping list, from Bunnings:
| 6G 40mm, zinc countersunk wood screws, 25 pk |
AU$3.98 |
| 6G 30mm, zinc, countersunk wood screws, 25 pk |
AU$3.98 |
...one small detail, the Zenith 40mm screws have recently been rebranded as 38mm.
EDIT 2020-01-11:
A clarification: the screws I used are self-tapping wood screws,
actually designed to be used without pre-drilling in soft wood. Example
link:
https://www.bunnings.com.au/zenith-6g-x-30mm-zinc-plated-hinge-long-threads-countersunk-head-timber-screws-35-pack_p2420068
The five pieces are now screwed together. Tomorrow, the plan is to install a mounting frame for the plywood floor.
Tags: nomad
Start of DIY plans for solar water distiller
Hopefully, anyway. Posting in stages to my blog, and if the end
result is good, then will put the plans together in a single page.
The basis of this is the "simple basin-type prototype #2", with some
further refinements, named as "prototype #3", as posted here:
https://bkhome.org/news/201912/designing-distiller-basin-type-proto3.html
I have refined the design in SolveSpace. Here is the diagram exported as a PNG:
The wood is dressed pine, 19mm thick. The two side pieces are to be cut from a single 235x19mm 1.2m piece of pine.
EDIT 2020-01-11:
Here is the SolveSpace file for the above picture. It is for SolveSpace v2.3 and will need to be uncompressed first:
https://bkhome.org/news/201912/files/basin3-frame3b.slvs.gz
For construction to be as simple as possible, I want the wood surface
on which the glass will lay, to be perfectly flat, hence the unusual
proportions on the back side. Along the back side, there will be a
64x19mm piece of wood, at 90 degrees to the plane of the glass. Then
there will be a 182x19mm (actually, Bunnings sell 184x19mm) piece
oriented vertical -- cut with a 20 slope on the top so as to fit against
the piece above it.
At the front, there will be a 94x19mm (will use 89x19mm from
Bunnings) piece, oriented at 90 degrees from the plane of the glass.
I will use 572x672mm glass, 3mm thick. You can see that the length of
the side piece is 592mm. That is to allow the glass to sit on top of
the wood frame, with 10mm wood outside of the glass, all around. I was
planning to use a router to cut an indent in the wood, so that the glass
can sit flush with the wood surface, however, to keep construction as
simple as possible, won't use a router.
Instead, the glass will just sit on top of the wood frame, held down
with aluminium brackets. There will be silicone sponge between glass and
wood.
Ideally, I would like these DIY plans to require absolute minimum of tools, perhaps even just a hand saw. So, the router is out.
My piece of glass is 572x672mm, taking off 9mm all round where it
sits on the wood frame, that leaves active dimensions of 554x654mm,
which is a surface area of 0.362 metre-squared. If you want to build a
bigger distiller, aiming for more than 1.8 - 2.0 litres per day in
summer, you can keep the wood dimensions that I have shown above, just
make the front and back pieces longer (in my case, they will be 672 -9
-9, which is 654mm). For example, if you use 572x872mm glass, that will
give you an active surface area of 0.473 metre-squared, upping the water
output to around 2.4 - 2.6 litres. However, you might then want to
consider using 4mm thick glass, for the strength.
The previous prototype used expanding foam for floor insulation, with
black silicone sealant spread directly on top of the foam. It was very
light, but the method needs improvement, as there were "waves" in the
floor. This time, I propose to use a piece of 6mm plywood:
...by "deep", I mean 527mm will be the measurement of the plywood
from front to back, and it will be 654mm long (or wide, depending on
your point of view). It will require some framing underneath. The floor
of the basin will be 60mm above the bottom of the distiller.
EDIT 2020-01-11:
When I got to actually constructing the distiller, I decided to raise
the basin floor by 6mm, so the "54mm" in the above photo has become
60mm. Also, the plywood now measures 530.7x654mm. The corrected
SolveSpace v2.3 file (uncompress it first):
https://bkhome.org/news/201912/files/basin3-frame3b-internal2.slvs.gz
I have not yet decided what insulation to use. I am now wary of
expanded foam! Might use fibreglass insulation -- Bunnings do not sell
individual batts, so maybe I can use the leftover batts somewhere else.
Fibreglass insulation does have one advantage -- I can take it out if
want to mess around with the plumbing underneath. Also, if the plywood
gases due to the heat, the gas can escape.
There is proposed to be plywood on the bottom of the distiller.
I have toyed with various ideas for the floor and sides of the basin,
such as black silicone sheet stuck onto the floor. However, have
decided to stay with what has already been tested, and used in the
previous prototype, spreading silicone sealant onto the wood.
Here is the shopping list for the pine:
| Section (mm) |
Length (m) |
Price (AU$) |
| 42x19 |
2.4 |
7.65 |
| 64x19 |
1.2 |
5.00 |
| 89x19 |
1.2 |
6.00 |
| 184x19 |
1.2 |
13.00 |
| 235x19 |
1.2 |
21.00 |
And marine plywood:
| Dimension (mm) |
Price (AU$) |
| 1220x810x6 |
34.60 |
A grand total of AU$87.25.
EDIT 2020-02-13:
Bunnings doesn't seem to have that size of marine plywood any more. You
need sufficient for the floor of the basin and underneath the distiller.
You may have to buy a bigger piece, or two smaller pieces. Not online
anyway -- you could check in-store.
If I was to rummage around in scrap yards, I am sure that suitable
wood could be found, at a fraction of that price. For me, it is a matter
of convenience, as the Bunnings store is only a 5 minute drive from my
home. Also, I want pine for the light weight, but if that was not a
concern then a hardwood would be OK, and more durable. Perhaps also,
marine plywood is not needed, a cheaper plywood should be OK - or a
sheet of aluminium or steel.
Tags: nomad
Designing distiller basin-type proto3
This is intended to be the "final" design, for which I will
create DIY plans. I have ideas about a collapsible design, however,
think it better to stay with the latest basin-type that is working very
well, with some tweaks.
The simple basin-type, prototype #2, was evaluated here:
https://bkhome.org/news/201912/further-analysis-of-basin-type-distiller-test.html
...it achieved efficiency 87% relative to the F-Cubed C1000, and 47% absolute efficiency.
Note: F-Cubed claim 55% for the C1000, but 65% for the C3000. The latter is the same width, but 3 metres long, and apparently the longer air rotation path improves the efficiency.
I am proposing that the DIY plans be basically the same as proto-2, except for:
- Thicker insulation in base, 60mm instead of 35mm
- Thicker side walls, 19mm instead of 12mm
- 3mm glass instead of 4mm
- 20 degrees glass angle, instead of 10 degrees
I did two tests of prototype #2, the second with the distiller
sitting on extra insulating plywood and a towel, and got higher water
output, 2.06 litres up from 1.86 litres.
The thinner glass is expected to improve efficiency. The higher angle
of the glass will decrease efficiency, however, the distiller will work
better in winter.
I will use a 572x672mm sheet of glass, 3mm thick, one of the pieces that was used in the sloping wick-type prototype #4.
I constructed a side-view in SolveSpace:
https://bkhome.org/files/basin-proto3a.slvs.gz
Note: SolveSpace hangs on my laptop. This is a known problem with intel video. In my case, the fix was to exit X to the commandline, and run "xorgwizard", and change from "sna" acceleration to "uxa" acceleration.
This is the side view, outside dimensions:
...the yellow-filled area is insulation, mostly 60mm thick, but tapering down to 18mm at the back (to keep the width to 235mm).
I managed to constrain the thickness so that a 235x19mm, 1.2m, piece
of pine, will do the job for the sides. Although the glass short-side is
572mm, another 10mm is added on each end for the pine sides. It is
proposed to use the router to indent the glass into the wood frame.
The right side of the above snapshot is messy, so here it is expanded:
...only 30mm between floor of basin and top-outside of the glass, but
that is enough. The water depth is only going to be about 5-10mm.
The design looks reasonable, so a trip to Bunnings is coming soon...
Tags: nomad
Further analysis of basin-type distiller test
I posted a couple of days ago, a showdown between three solar water distillers:
https://bkhome.org/news/201912/solar-distiller-showdown-take-2.html
That was a very hot day, the ambient temperature peaking at 41
degrees C (106 Fahrenheit), with a slight breeze (11-23km/h, as reported
by the Bureau of Meteorology for my suburb), and the distillers
gave their best. My simple basin-type was measured to be 87% as
efficient as the F-Cubed c1000 distiller.
So what is the absolute efficiency of my basin-type? Well, taking the
claim by F-Cubed that the C1000 is 55%, that works out that the
basin-type is 0.87*55, which is 47.8%. But, can I calculate it myself,
from basic principles?
Interesting question. I looked at some research papers, and the
formulae given are complicated, or confusing (for me anyway). However, I did find some web pages with basic explanations...
From basic principles, for a day test, we want the energy of the sun
coming in, the water output, and a conversion constant which is the
energy required to convert the water to distilled water. That constant
is called "the latent heat of vaporization".
This is not my field. I was a solar energy researcher for awhile, in
1979-80, but that was in photovoltaics. Besides, I was an electronic
engineer. Anyway, from online reading, this seems to be the appropriate formula:
Efficiency (%) |
= |
Water-out (kg) x latent-heat-of-vaporization (kJ/kg) Energy-input (kJ) |
x 100 |
Latent-heat-of-vaporization is a constant, 2260.
Distiller water output is shown as kilograms, but 1 kilogram equals 1 litre. My basin-type gave 2.06kg.
That leaves energy input, in kilojoules. This is the awkward one to
calculate. The sun was pouring energy into the distiller, and I took
hourly measurements of the instantaneous power input, in watts per
metre-squared.
1 joule is 1 watt times 1 second. Joule is an energy figure, so if I
break the day into 1 hour chunks, I can just multiply the watts hitting
the distiller times 3600 seconds (1 hour), to calculate the energy.
The problem though, is that the sun is hitting the distiller at an
angle, quite an acute angle early in the morning and late afternoon. I
need to calculate the distiller surface area that is perpendicular to
the sun, at each hour of the day. To help with that, there is a graph
here:
http://www.see.murdoch.edu.au/resources/info/Tech/house/index.html
This is mid-summer here in Perth, Australia, and the glass angle is
10 degrees, so at midday the sun is directly perpendicular to the glass
-- so that one is easy, the area is just the area of the glass -- well,
less the thickness of the wood frame it is sitting on.
There needs to be a start-time and end-time for the analysis. I took
8.00am as the start-time, as the distiller was mostly in shade earlier
than that, and hadn't even started to warm up at 8.00am. I set the
end-time as 5.00pm, as virtually no water was coming out after that.
With the help of the above link, I constructed this table:
| Time (am,pm) |
8.00 |
9.00 |
10.00 |
12.00 |
2.00 |
3.00 |
4.00-5.00 |
| Irradiance (W/m2) |
840 |
970 |
960 |
1012 |
1005 |
970 |
917 |
| Perpendicular area (m2) |
0.216 |
0.27 |
0.317 |
0.352 |
0.317 |
0.27 |
0.216 |
| Power into distiller (W) |
181 |
262 |
304 |
456 |
318 |
262 |
198 |
| Energy into distiller (kJ) |
651.6 |
943.2 |
2188.8 |
3283.2 |
1144.8 |
943.2 |
712.8 |
...the energy is the power times seconds, divided by 1000, giving kilojoules.
The total energy input is the sum of the entries in the bottom row, which is 9867.6 kilojoules. Putting it into the formula:
Efficiency |
= |
2.06 x 2260 9867.6 |
x 100 |
| = |
47 |
The basin-type distiller has an absolute efficiency of 47%
This agrees closely with the earlier estimate of 47.8% ...I kid you
not, I did not fiddle with those figures. There is some approximation
involved calculating the energy input, but seems to be pretty close to
the actual energy input.
This is very pleasing. Various researchers have given different
estimates of the maximum efficiency obtainable from a simple basin type,
from 30% to 45% (and higher for a "non simple" design, such as
ribbed-floor in basin, or a stepped-basin, up to around 60%), so I am at
the top for the simple basin-type.
There were a couple papers that I read, where I could not agree with
the logic of the efficiency calculations. For example, one paper claimed
a seasonal efficiency variation from 14.8% to 31.1%, but it did not
consider the angle of the sun, that is, the actual energy hitting the
distiller. I thought that the meaning that they had given to the word "efficiency" was wrong, but I won't post
links to those papers, as, as I have stated, this is not my field.
Further thoughts on tilted wick-type versus simple basin
I have already indicated that I am now favouring the simple basin-type, due to simple construction and easy-of-use.
There is another point to consider: the survival of pathogens, even the possibility of them breeding inside the distiller.
The simple basin-type exposes almost every part of the interior to UV
radiation -- the exception would be just behind the distilled-water
runoff at the front of the distiller -- however, I think that the
white-painted walls would be reflecting UV into every shaded area. On
the other hand, the tilted
wick-type has a lot of places where pathogens can hide from UV light. In
particular the F-Cubed design, where air rotates around the underside,
but even a simpler conventional design would allow pathogens to hide in
the wicking material.
Then there is internal temperature, the higher the better. Again, the
basin-type wins. An internal temperature of 80 degC might not
immediately kill some pathogens, but they are bound to be killed
eventually.
My recent tests highlighted the need to have sufficient water flow
through the tilted wick-type, to avoid dry patches. This can result in a
lot of waste water. With the C1000, There was about 15 litres in the
container, and I had to refill it early in the afternoon. So,
mid-summer, rough estimate is to have at least 25 litres in the
container, and also mounted high enough, about 1.4 metres above the
ground.
With the simple basin-type, there is no worry about water delivery
rate. You just put in enough at start of day -- which could be governed
by an overflow outlet inside the distiller. In my test, I put in 5
litres, and got 2 litres of distilled water. The left-over water then
needs to be flushed out at end of day, to avoid build-up of sediments.
Well, probably more importantly, left-over water is required so that
there are no dry-spots on the basin floor, which would cause sediments
to become baked-on to the floor.
Perhaps running some extra water through the distiller at end of day
would help with flushing. The design could quite easily cater for this.
So perhaps comparing the two types of distiller from the water-maintenance side of things is a 50-50 situation.
Well, no, I think that the basin-type wins, as in a campsite
situation I don't really want to have to provide something 1.4 metres
high on which to place the water container. The alternative is a small
water pump, but that is getting too complicated.
Tags: nomad
Solar distiller showdown take-2
Yesterday I tested three solar water distillers side-by-side:
https://bkhome.org/news/201912/solar-distiller-showdown.html
There was a hiccup with the F-Cubed panel, the cloth becoming partly
dry, so have repeated the test today. Friday, 13 December, 2019, in
Perth, Australia.
Two changes from yesterday. This time I lowered the water container
for the F-Cubed panel, down one rung on the ladder -- so the water
container went from 1430mm above ground, down to 1120mm. Secondly, put a
bit more insulation under the basin-type distiller -- previously had
one 12mm MDF, this time added a 16mm plywood sheet and a towel:
The test proceeded same as yesterday, here are the results:
| Time am/pm |
Sun W/m2 |
Amb. degC |
Top, degC C1000, wick, basin |
Comments |
||
| 8.00 |
840 |
34.7 |
38.3 |
39.7 |
33.8 |
|
| 9.00 |
970 |
35.4 |
58.2 |
49.5 |
44.8 |
Official: 34degC, 23km/h |
| 10.00 |
960 |
36.9 |
67.2 |
59.1 |
58.4 |
Official: 36degC, 23km/h |
| 11.00 |
1030 |
38.7 |
72.4 |
66.0 |
70.9 |
|
| 12.00 |
1012 |
39.9 |
74.5 |
72.0 |
79.2 |
Dry patches in C1000 |
| 1.00 |
960 |
40.8 |
69.1 |
70.8 |
81.5 |
Official: 39degC, 13km/h |
| 2.00 |
1005 |
40.0 |
73.5 |
69.8 |
79.6 |
Official: 40degC, 11km/h |
| 3.00 |
970 |
40.9 |
68.3 |
63.9 |
75.3 |
Official: 41degC, 14km/h |
| 4.30 |
890 |
38.7 |
49.6 |
47.9 |
61.7 |
Official: 39degC, 26km/h |
Stopped at 5.30pm.
About midday, dry patches were starting to appear in the cloth of the
C1000, at the bottom. I moved the water container back up to the higher
rung, and that fixed it, quite quickly. Lesson: better to have more
water flowing through than not enough!
Notice how hot the basin-type got! One good thing -- that will kill any pathogens inside the distiller.
Here are the results:
| C1000 |
wick |
basin |
|
| Tally (litres) |
6.77 |
1.53 |
2.06 |
| Normalized (litres/m2) |
6.77 |
4.60 |
5.89 |
Wow, stellar performance! So, the simple basin-type is 87% as efficient as the F-Cubed C1000 distiller. Pretty good.
I am wondering if my wick-type distiller might have performed better
with more water flow through it. Waste water output reduced to just
about nothing in the afternoon, but I could not see if the cloth was
drying out. Although I very much like the basin-type because of it's
simplicity, both in construction and usage, I might do one more test
with the wick-type, with the water container higher up ....maybe.
Tags: nomad
Solar distiller showdown
Today, Thursday, December 12, 2019, in Perth, Western Australia,
latitude 31 degrees in the Southern Hemisphere, it is mid-summer. The
prediction for today is 40 deg C (104 Fahrenheit) and sunny. I decided
it is time for a showdown, a "shootout" between the F-Cubed Carocell
1000, my tilted wicking-type prototype #4, and my simple basin-type
prototype #2.
There were individual tests done on these:
https://bkhome.org/news/201906/testing-f-cubed-carocell-1000-solar-distiller.html
https://bkhome.org/news/201911/solar-distiller-prototype-4-first-test.html
https://bkhome.org/news/201912/testing-basin-type-solar-distiller-prototype-2.html
In those tests, I published comparative efficiency figures, however,
they were based on tests taken at different times of the year, different
weather conditions, and also some figures published by the F-Cubed
company.
The only way to accurately compare them is to test them together. Which I have done today.
I started putting them out in my backyard about 7.00am. A gusty
breeze. They are in the shade of my garage, but that is only a temporary
situation. This photo shows the shading:
...which does put the F-Cubed panel at a disadvantage, however, none
of them were producing any output at this time, and the shade rapidly
disappeared. By 8.00am, there was just a bit of shade in the bottom
corner of the F-Cubed panel.
One good thing, the placement, and being mid-summer, avoids the
afternoon shade from the patio, so I was able to run the test until late
afternoon.
There was some haziness in the sky, which persisted for most of the
day, though still got fairly high sun intensity readings -- but perhaps,
the distilled water output might not be quite as high as if the sky was
clear blue.
Here are the tabulated readings. The "Top" temperature measurements
are taken with the IR meter, held about 3 inches above the glass, about
3/4 of the way up. Ambient readings were obtained by pointing the IR
meter into the patio.
| Time am/pm |
Sun W/m2 |
Amb. degC |
Top, degC C1000, wick, basin |
Comments |
||
| 8.00 |
840 |
26.5 |
30.7 |
29.1 |
25.7 |
No water o/p yet |
| 9.00 |
900 |
29.4 |
50.3 |
44.5 |
40.1 |
Official: 28degC, 23km/h |
| 10.00 |
950 |
30.8 |
63.3 |
54.8 |
53.8 |
Official: 31degC, 21km/h |
| 11.00 |
910 |
34.1 |
70.2 |
62.5 |
64.1 |
Official: 34degC, 26km/h |
| 12.30 |
750 |
36.4 |
66.8 |
61.9 |
70.7 |
Problem with C1000 panel |
| 1.00 |
1005 |
37.2 |
66.8 |
61.9 |
70.7 |
C1000 almost recovered |
| 2.20 |
965 |
37.0 |
66.0 |
62.3 |
73.4 |
Official: 38degC at 2.00pm |
| 3.15 |
960 |
36.8 |
65.8 |
59.1 |
71.0 |
|
| 4.00 |
950 |
36.0 |
58.9 |
53.2 |
65.5 |
Official: 39degC, 16km/h |
| 5.00 |
855 |
36.6 |
45 |
46.8 |
56.8 |
Official: 39degC, 18km/h |
The test was stopped at 5.45pm.
There was a problem around midday with the C1000 panel. I had reduced
the water inlet flow, by turning the tap from the water container to
nearly off. This was because I thought too much water was flowing
through the still. I probably should have just lowered the water
container to reduce the head. Anyway, at 12.30pm discovered that most of
the wicking cloth had gone dry.
This is a bad situation, as it can take awhile for the cloth to wet
right through again. When dry, water tends to run over the surface,
instead of seeping into the cloth. Anyway, it recovered fairly quickly,
and the cloth looked Ok by about 1.00pm. It will be expected that this
will reduce the distilled water output.
Notice also the sun irradiance (intensity) was only 750 watts per
metre-squared. This was due to increased haziness in the sky around
midday.
Here are the results, the accumulated distilled water output for the day:
| C1000 |
Wick |
Basin |
|
| Tally (litres) |
5.32 |
1.27 |
1.86 |
| Normalized (litres/m2) |
5.32 |
3.817 |
5.314 |
There was only 5.32 litres from the C1000 panel, I would have
expected about 6 litres. This test will have to be repeated, probably
tomorrow.
The table shows the simple-basin-type giving almost as much output as
the C1000, and even higher than the previous test of 1.85 litres (see
previous test link at top of this page). That previous test was a hotter
day, and higher sun intensity -- so how come I got an extra 0.01 litres
today?
In the previous test of the basin-type, the distiller was sitting on a
small picnic table, same today, but I placed a 12mm thick sheet of MDF
on the table, so there was more insulation, which is known to be an
important factor for efficiency.
Note, the distillers were not moved all day. They were oriented facing due North.
My tilted wicking-type distiller gave very poor performance. It is
now eliminated. Though, will probably include it in tomorrow's showdown,
since it is setup.
Tags: nomad
Radical rethink of the basin-type distiller
I posted this morning some reflections on how the simple-basin
prototype #2 achieved a high efficiency, with thoughts to enhance even
further:
https://bkhome.org/news/201912/reflections-on-the-basin-type-proto-2-test.html
I have now got an idea how the frame can be collapsible, completely
flat, for easy transportation. That is one new thought, that will be
explained in a later blog post.
Another rethink is how to achieve a flat black floor for the basin.
So far, have been spreading black silicone sealant, two 300gm tubes
required for a 0.35 - 0.4 metre-cubed floor.
There are various problems with spreading silicone sealant. One is to
find all pin-head holes. Another is to get the surface smooth. Then
there is the messiness of the application.
A solution is a glass floor for the basin, with a thin black silicone
sheet stuck on it. This would give perfect flatness, that will not
warp, and suitable for very high temperatures.
The problem is to find a supplier of a large enough black silicone sheet. The exact dimensions yet to be determined, but somewhere around 700x550mm, 1mm thick. Last night I made some online enquiries to Australian suppliers, today only received one reply.
Reglin Rubber, based in Victoria, sent me a quote for a roll, 1200mm width, 10m long, sheet thickness 1mm. The quote is AU$148 including GST, and AU$40 postage. That would be enough for 28 distillers.
The biggest that I could find on eBay is 500x500mm, ditto Amazon. However, on Aliexpress I found this:
https://www.aliexpress.com/item/32910589054.html
...1m by 1m, 1mm thick, black silicone, AU$18.76 plus GST, and
AU$27.05 for EMS ePacket postage (13 - 20 days delivery to my home, from
China). Grand total AU$50.39. Rather a lot of money for a piece of
silicone sheet, but want it, so ordered it.
EDIT 2019-12-09:
Yikes! I have received another reply. From Complete Rubber, based in Victoria:
Thinnest Black Silicone we can offer is 1.5mm Thick
1000 x 1200mm piece costs $499.00 + GST + Freight
We can supply 0.5mm, or 1.0mm Thick in RED or Translucent colour if acceptable
0.5mm - 1000 x 1200mm Piece @ $441.00 + GST + Freight
1.0mm - 1000 x 1200mm Piece @ $385.00 + GST + Freight (Yes cheaper as is more common size purchased in the Market Place)
...a bit of a jump from $18.76 direct from China, and $148 for 10 metres from Reglin Rubber.
Tags: nomad