Tiny Might skimmer rockin'

[BeanAnimal]

Man your just keep going.... HAHN I WAS CORRECTING YOUR COMMENTS.



Once again you stated EXTRUDED in several different contexts. Extruded and COLD ROLLED are 2 very differnet process. Niether matter to the thread or the argument, other than the fact that once again you spouted off as an expert in something in an attempt to show I was wrong, and just didn't get it right.

If you only point was that glued up aluminum may be easier than cast, you could have said that. You DIDNT... it took you 5 posts and half a science book.

Hahn you keep getting stuck in useless details and dragging this thread through the mud. You know enough about heatsinks to be dangerous and that it. I am getting tired of showing you why and where you are wrong. You just keep going in circles like a broken record.

BUT ONCE AGAIN: A heatsinks ability to remove heat is not a sole function of the fin thickness. It is a function of the overall design and the way it handles airflow and distributes the heat from it's source.

Why are you stuck in irrelavant points. Pleae go back and read your first post and get it through your head that this conversation is a result of those comments.

Assuming too much? Sorry again dude, given the same base, thicker thins will conduct more heat than the same number of thinner fins. It is a simple matter of MASS. Like I said, your in over your head again. Please stop trying to explain things that you don't fully understand.

Of course we could use a small fan. We could use solid gold and a ducted turbine too. Your all over the place... and again this is all about your original comments CANT YOU SEE THAT YET?

I have not spun anything. I am just replying to your initial comments and the ever growing list of technology and terms you are bring into your responses that really have nothing to do with the original post or comments.

Shall I repeat what you said?

heatsinks are best if they are extruded from copper or aluminum.... casts or mixed materials usually have poor heat transfer.

I then replied:

Well lets look into this.

1) Alloys are used for heatsinks on a regular basis. What in the world do you think aluminum is? It is an alloy in the form we use it, not a pure element. It contains a fair amount of Iron, Silicon and Copper (among many other lesser quantits of metals).

2) Cast heatsinks are very common. VERY COMMON. Cost is a major factor. Needles to say, the thermal capacity between a cast and extruded part is dictated by much more than the base material or process.

3) We are certainly not out to engineer a heatsink to eeek every watt out of our pumps. The idea is for a general design that will remove some heat and help the pump run a bit cooler.
4) MOST COPPER heatsinks are either CAST or BONDED.

So in a nutshell, your statements are not really valid. There may be some truth to the statements (other than the comment about extruded copper), but they just has no bearing here. It is like saying "gold is a better conductor than copper, so you should not use copper for wire, you should look into Gold" The statement has some truth but is useless in most cases... I hope you see the point here.

Please re-read those 2 posts until you understand. Then tell me why we are talking about grains, and boundries?

 

[BeanAnimal]

<a href=showthread.php?s=&postid=7903702#post7903702 target=_blank>Originally posted</a> by smjtkj
OK guys, we had some strange occurances today on the tiny might, This morning the wattage rose to 78 watts for no apparent reason. It remained that way for the hour before I left for work. I just left it that way and went to work. There was no obvious ill effects that I could see. When I returned home this evening thepump is running at 68-69 watts! Still rockin'! I know someone has a reason why this happened.

Voltage? Not sure what you using to read the watts (kill-a-watt) and how it measure watts.

Back pressure? due to slight change in foam level or surfactants. Maybe trapped air?

Does the current draw change with the PH or other water chemistry.

What about the density of the air in the house (humidity)?

 

[BeanAnimal]

Or for that matter the temperature in the pump room. Higher temps will mean more current draw due to resistance increasing. This may be a stretch for that many watts... but then again a slight temp change in the room could cause a somewhat larger change in the pumps operating temp.

 

[spazz]

i think you two guys need a time out in the corner. lol lets just wait and see what the experts say on the subject. that company has tones of experts that are way over my pay grade that will wip up a good design that will work for many different applications and pump housings. i would like to get a design that can be mounted to different sized pumps so people can reduce the heat that is transfered tothe water in the tank. im hoping they can come up with a flexable design that will wrap around the motor housings.
so can we just wait to see what they come up with guys. truse for now????
i would like to figure out what would cause the jump in wattage for 1 hour and then the wattage dropped right back down again. this is perplexing and needs to be figured out.
also i would like ideas for a totaly different designed needle wheel. what do people think of square pins??? or rectangle pins???triangle pins???? do you see any advantages to any of those and what would be the best position for them. im looking to reduce the wattage and increase water/air flow.
ideas with drawings would be great. i have a small sheet of 1" thick acrylic i want to play with and see if i can machine out the pins right into the wheel. that way i can have any design i want for the pins.

 

[hahnmeister]

"Assuming too much? Sorry again dude, given the same base, thicker thins will conduct more heat than the same number of thinner fins. It is a simple matter of MASS. Like I said, your in over your head again. Please stop trying to explain things that you don't fully understand."
-BeanAnimal

if the surface area of both are the same then the thicker fin can absorb more heat, but the thinner fin is used to get more surface area in the same space. Thats how they are able to perform better. If this wasnt the case, now that computer CPU's are making more heat than ever, why have HSF companies quit making cast heatsinks in favor of methods that give them thinner fins? Besides, with the pump shroud, we already have a good deal of mass to work with as a base for the sink... I dont know that we need to add anymore with all that already... we need more surface area.

Spazz, your interest in different pins for NW's interests me greatly. I have been thinking about this as well... Without boring you, I was thinking that using the same size, a square pin might be a good idea. Round pins are more aerodynamic than flat sided shapes (unless they are positioned on edge to slice), and slice through the air & water mix easier.

I was thinking that square pins might mean getting some of the lost head-pressure and flow back that is lost from the regular pump impeller because a flat faced paddle works better than a round one...

Just a thought... I was waiting to make one to test first and see.

 

[smjtkj]

<a href=showthread.php?s=&postid=7903839#post7903839 target=_blank>Originally posted</a> by BeanAnimal
Voltage? Not sure what you using to read the watts (kill-a-watt) and how it measure watts.

Back pressure? due to slight change in foam level or surfactants. Maybe trapped air?

Does the current draw change with the PH or other water chemistry.

What about the density of the air in the house (humidity)?

I look in the bubble diffuser chamber to see if there was anything that was dislodged from the needlewheel. Nothing there! It's being measured by a kill o watt meter. I don't know if the current draw changes or not with ph. my pH is pretty steady. It is controlled by a PH controller. I am kind of leaning towards trapped air. I am just not sure.

 

[hahnmeister]

Maybe a pin came lose or was rubbing on the shroud? The main disk shifted position? It could be as simple as the static charge of the plastic/carbon reacting with the water or perhaps even the regular 'breaking in' of composites in tank water on their way to developing a nice layer of tank scum. :bum:

 

[smjtkj]

The room temp is pretty consistent too. Actually cooler by a degree or so. I am not seeing any foriegn matter but I can't help thinking something was dragging the nw down some.

 

[smjtkj]

<a href=showthread.php?s=&postid=7903952#post7903952 target=_blank>Originally posted</a> by hahnmeister
Maybe a pin came lose or was rubbing on the shroud? The main disk shifted position?

What main disk are you referring to? The pins are all still in tact.

 

[hahnmeister]

The disk that the pins all fit into... they are in a flat disk, arent they?

 

[BeanAnimal]

Hahn of course you can get more thin fins in the same space as thick fins. I never said anything any different. I said that surface area can not be looked at without flow, and that the mass of the heatsink is imortant as well as the fin size and placement. Can we just get off the subject? I will ask you once again to read those first 2 posts and ponder just why we are here.

I welcome your input on the acatual design of the heatsinks for a motor and don't doubt for a minute that you have some good ideas, I never said you didn't. (back to the first two posts if you are in doubt about what my point was).

The radial fins are exactly what we are looking to do. The use of a fan is something that I think we want to avoid. It makes the design more complicated (fan mounts, shrouds, drilling, power supplies, bearings, noise... etc).

A simple passive heatsink ring with a clamp is likely going to be the most cost effective and functional in terms of varied pump sizes. Radial fins will not provide the best convection cooling, but again we are looking at <100 of disipation over a fairly large area. In reality, at 80 degree room temperatures, 20 watts of disipation are likely to bring about a dramatic change in heat transfer of the pump. Like I said my soda can proof of concept got me close to 1 degree. I did not measure my copper prototype yet (at least with any confidence), but know it is not much better ($20 worth of epoxy and copper later). It simply does not make good contact with the pump.

 

[BeanAnimal]

Spazz, I have an engineering request in for the thermoplastic heatsinks. I got one started several months ago but did not follow up with the engineer due to the lack of interest from the other people involved. I even purchased in injection molding book in hopes of building a small unit (likely something else to sit on the shelf, beside my casting oven plans, CNC mill plans, vacuum press parts, DIY jointer parts, unfinished power amps, arc welder plans... and whatever else sits on my unfinished projects shelf).

Bean

 

[smjtkj]

Oh OK, yeah but it is a solid piece . No way to shift without breaking.

 

[hahnmeister]

So you are sure that nothing in the pump can shift... the disk isnt unscrewing, the disk cant shift from front to back, etc.... thats all Im getting at. I wonder if you opened up the pump to take a look... I wouldnt worry too much at that unless something is coming lose.

 

[smjtkj]

Yeah I opened the wet end and all is well.

 

[BeanAnimal]

smj, can you get a diameter on that pump and a decent measurement of the room for a heatsink from front to back on the body?

 

[ChemE]

Spazz -- You really want to try something different, radical, and potentially groundbreaking? Do a single row of tightly packed square pins close to the outside of the impeller and then put another row of tightly packed square pins on the volute. The closer the clearance between the NW and the stators the better. You're basically making a poor man's ultra high shear mixer. My gut tells me that would cope with monster amounts of air and would chop it into nanobubbles, forget microbubbles.

 

[smjtkj]

It is about 3 1/2 diam and 5 long.

 

[smjtkj]

<a href=showthread.php?s=&postid=7904374#post7904374 target=_blank>Originally posted</a> by ChemE
Spazz -- You really want to try something different, radical, and potentially groundbreaking? Do a single row of tightly packed square pins close to the outside of the impeller and then put another row of tightly packed square pins on the volute. The closer the clearance between the NW and the stators the better. You're basically making a poor man's ultra high shear mixer. My gut tells me that would cope with monster amounts of air and would chop it into nanobubbles, forget microbubbles.

The only problem is attaching the pins to the volute. It is glass filled nylon.

 

[hahnmeister]

Yeah, that was somewhat was I was thinking too. I think that the idea has some validity. The pins could be arranged with their flat surfaces to both increase centrifugal force and bubble chopping. If nothing else, the square pins (or triangle, or whatever, as long as it has a flat face) would be interesting and could increase throughput.