Tiny Might skimmer rockin'
- Thread starter smjtkj
- Start date
BeanAnimal
Premium Member
You can pour acrylic (I think even TAP has some compounds).
A simple latex mold would likely do the trick, and that could be done rather easily. On the other hand it would be rather easy to mill an new volute using solid PVC (pretty cheap) and CNC for the bolt holes and flange seals and needle seats, as they are directly opposite the impeller. The rest of the cavity could be done by hand and a die grinder.
Or of you wanted the part could be made in 2n layeres and then glued up. That way you could CNC the inner profile in a 3 axis machine.
A simple latex mold would likely do the trick, and that could be done rather easily. On the other hand it would be rather easy to mill an new volute using solid PVC (pretty cheap) and CNC for the bolt holes and flange seals and needle seats, as they are directly opposite the impeller. The rest of the cavity could be done by hand and a die grinder.
Or of you wanted the part could be made in 2n layeres and then glued up. That way you could CNC the inner profile in a 3 axis machine.
Spazz and I have talked about cutting a new cover out of acrylic to see what is going on in there and also have more space in the housing for air water mixture. They could actually be mounted in the cover having them long enough to reach the back of the volute housing. That way the back that holds the bearing seal would be intact. Maybe he wouldn't mind doing two. One with and one without.
hahnmeister
In Memoriam
How do you mean? Perforations?
spazz
New member
keep the ideas comming guys. all of these ideas have some good value to them. the only concern we have is wattage increase here. we dont want to increase the wattage of the pump at all. so we need to look at it from that angle too. i think i might go with a square puned wheel to start and them a triangle one. but the pns cant be too close together. other wise the wattage draw will increase. the pins in the housing is also a good idea but will that slow donw the flow of water in the housing? or will it just shread the water better. we dont want any restriction.
also we need to think about a new air injection system. i think the current way of injecting air is not working as well as it could. seeing the air pump is cheaper to run than the water pump im wondering if there is a way to increase the velocity of the air water mix using the air pump to push the water along faster at the point of injection. kind of like a reverse venturi. where the air would suck more water into the pump. by increasing the air tothe pump and sucking the water with it your force feeding it. and it dont need to "draw" the water air mix into the pump. this would increase the air water mix going to the pump and you wouldnt cavitate the pump. then you only using the pump to chop up the air water mix.
any ideas?????
also we need to think about a new air injection system. i think the current way of injecting air is not working as well as it could. seeing the air pump is cheaper to run than the water pump im wondering if there is a way to increase the velocity of the air water mix using the air pump to push the water along faster at the point of injection. kind of like a reverse venturi. where the air would suck more water into the pump. by increasing the air tothe pump and sucking the water with it your force feeding it. and it dont need to "draw" the water air mix into the pump. this would increase the air water mix going to the pump and you wouldnt cavitate the pump. then you only using the pump to chop up the air water mix.
any ideas?????
Well, the impeller has been chopped up to permit more active thrashing of the air/water mixing so perforations in each individual rod may encourage even more micro thrashing.
Imagine tiny holes drilled in each of the rods parallel to the back plate of the impeller or perpendicular to the length of the rod. They might be arranged in a random pattern, cross hatched or even in line or counter to the direction of rotation. NOT down the center of the rod.
Another consideration might be making the rods wavy or perhaps ringed similar to the corrugations on a flexible tube. Or maybe even flexible so they bend with the rotation of the impeller.
I worked for some time in an industry that built large fans for cleanrooms for the semi-conductor industry. Because of the extremely high volumes of air required for maintaining the cleanliness of the space, noise became a huge concern. We began experimenting with feathering the trailing edge of the blades of the fan wheels about the time the industry was hit by an abundance of manufacturing space so the work died off. But during the brain storming phase of the process to improve the efficiency of the fans, many ideas concerning the shape of the blades were discussed. Of course we were looking for efficiency of the wheel not the ability to thrash. :eek2:
Just some random thoughts.
spazz, some of the ideas suggested in the previous post(s) may very well increase the power consumption of the pump. However they might also increase the mixing of the air/water and/or increase the efficiency of the pump's ability to move the air water mixture.
From my perspective I just wanted to throw some ideas out for consideration or maybe help spark some other ideas. I appreciate the ideas presented concerning the shape of the cone (head) relative to bubble flow as well as the width-height ratio discussion.
From my perspective I just wanted to throw some ideas out for consideration or maybe help spark some other ideas. I appreciate the ideas presented concerning the shape of the cone (head) relative to bubble flow as well as the width-height ratio discussion.
BeanAnimal
Premium Member
Spazz, a couple of thoughts.
Firstly we don't want to increse the water flow to the pump. We want to handle a higher ratio of air.
You really can't "force" more water into the pump, as it would disturb the balance the the impeller is capable of handling.
These are not fixed displacement units, but they still do maintain a somewhat linear equillibrium with regards to the amount of "anything" that they can throughput.
That said, the smoother the water path into the pump, the better it will operate and the better the air will mix without turbulance. The key is laminar flow into the pump volute, as the volute (nw or not) works in the same basic principles of the venturi. The smoother the flow (even with the bubble chopping) the higher the output.
Firstly we don't want to increse the water flow to the pump. We want to handle a higher ratio of air.
You really can't "force" more water into the pump, as it would disturb the balance the the impeller is capable of handling.
These are not fixed displacement units, but they still do maintain a somewhat linear equillibrium with regards to the amount of "anything" that they can throughput.
That said, the smoother the water path into the pump, the better it will operate and the better the air will mix without turbulance. The key is laminar flow into the pump volute, as the volute (nw or not) works in the same basic principles of the venturi. The smoother the flow (even with the bubble chopping) the higher the output.
hahnmeister
In Memoriam
The more water we get into the pump, the more air gets in... these values may not be proportional, but in general, if we want to increase the air intake by say... 20%, we might have to do it with a water increase of something like 5%. I just dont see how we could increase the air intake w/o increasing the water intake w/o choking the pump or something.... I mean, using the intake valves/restriction on the venturi we should already be at the peak air capacity for the water volume throughputs. I could see making the pump draw more water/air with different pins, or a mix of blades and pins, and then re-tweaking it so it sucks the most amount of air... but it comes down to the intake venturi, no? If you want more air, you are going to need more suction... which means more water... right?
smjtkj, I dont think the angle of the air intake matters much. The air coming in just doesnt flow fast enough to act like its being injected... it being sucked in from a relative static source. If it was an issue, I think we would see more (I cant think of any at all) venturis (both intake and mazzei/output ones) that used angled air inputs.
smjtkj, I dont think the angle of the air intake matters much. The air coming in just doesnt flow fast enough to act like its being injected... it being sucked in from a relative static source. If it was an issue, I think we would see more (I cant think of any at all) venturis (both intake and mazzei/output ones) that used angled air inputs.
hahnmeister
In Memoriam
true, but in that case, the amount of air is only determined by the amount your air pump pushes... you dont even need a venturi or valve tweaking really or anything... the air pump does everything. I suppose you could put a valve on the water intake of the pump... that way you could turn down the water throughput to the bare minimum before the pump chokes to reduce turbulence from the water running through. I could see that being of value (more value than a venturi on the intake even) in the case of a forced air system... you could really turn the water intake down then because who cares how low the water flow is... as long as you have just enough for bubbles. Know what I mean?
You really have no need to tweak anything with regards to the needlewheel, venturi, etc on your skimmer... the air volume is determined by your pump, and the water volume is up to you if you use a valve on the intake... many skimmer owners would love to have that kind of control.
You really have no need to tweak anything with regards to the needlewheel, venturi, etc on your skimmer... the air volume is determined by your pump, and the water volume is up to you if you use a valve on the intake... many skimmer owners would love to have that kind of control.
BeanAnimal
Premium Member
han, you keep refering to "seeing more" of this or that. Though it is a nice thought, it just does not happen as the norm. You keep assuming that manufacturers refine every (or for that matter ANY) aspect of their designs. They in fact do very little refining of anything. They do the bare minumum that works to get products moved off the shelf.
How many blenders and food processors have you seen with sharp corners that are hard to clean, or the drip plate for your Mr Coffee... try cleaning that sometime. Look at any everyday object and you can instantly come up with refinements that would make it perform better, be more ergonomic, cheaper to produce, etc.
Not saying you are wrong, just that you are looking at products through the wrong lens.
How many blenders and food processors have you seen with sharp corners that are hard to clean, or the drip plate for your Mr Coffee... try cleaning that sometime. Look at any everyday object and you can instantly come up with refinements that would make it perform better, be more ergonomic, cheaper to produce, etc.
Not saying you are wrong, just that you are looking at products through the wrong lens.
BeanAnimal
Premium Member
With regards to the air water:
You can certainly get more air with the same amount of water throughput. These pumps are very simple flow devices, the smoother the fluid path, the more efficient the design. Turbulant flow into the body causes a performance hit right off the bat.
By decreasing the turbulance into the pump, it will be able to move (change the velocity) of more fluid more efficiently.
We are pushing more air into the pump than it can draw in on it's own. That air is displacing water that would otherwise be drawn in. The idea is to inject smaller bubbles into the intake, instead of large blobs of air.
The intake of the pump is certainly at a high enough velocity to entrain air. Moving the air injection point in relation to the pumps impeller may make a difference and is certainly something to look into.
You may also want to look into using several small diameter lower pressure air injectors instead of one large high pressure injector. It may or may not help.
You have already gone a long way into making the pump work better by working in the inside of the volute and housing. Smooth is what counts.
You can certainly get more air with the same amount of water throughput. These pumps are very simple flow devices, the smoother the fluid path, the more efficient the design. Turbulant flow into the body causes a performance hit right off the bat.
By decreasing the turbulance into the pump, it will be able to move (change the velocity) of more fluid more efficiently.
We are pushing more air into the pump than it can draw in on it's own. That air is displacing water that would otherwise be drawn in. The idea is to inject smaller bubbles into the intake, instead of large blobs of air.
The intake of the pump is certainly at a high enough velocity to entrain air. Moving the air injection point in relation to the pumps impeller may make a difference and is certainly something to look into.
You may also want to look into using several small diameter lower pressure air injectors instead of one large high pressure injector. It may or may not help.
You have already gone a long way into making the pump work better by working in the inside of the volute and housing. Smooth is what counts.
BeanAnimal
Premium Member
Yes a valve to restrict the water intake would be a good place to start trying to see what the max ratio of water to air is.
The valve will cause turbulance so it should be a good distance from the actual impeller and air intake. You can then replace it with a suitable size reducer (orifice) if it really needs to be close to the pump body.
The valve will cause turbulance so it should be a good distance from the actual impeller and air intake. You can then replace it with a suitable size reducer (orifice) if it really needs to be close to the pump body.
ChemE
New member
I think Bean has hit on something here. What about feeding air into the pump via one or more of the AES extra fine pore air stones? They only put modest back pressure on the air pump and the bubbles they create aren't quite as fine as those that a NW will generate but they are still pretty fine. Might allow you to feed air at a higher flow rate without choking the pump. Or it might allow you to feed the same amount of air and get finer bubbles since the Tiny Might has less chopping to do.
Guys this is getting good! Maybe a manifold shaped like a UV sterilizer with a couple of air stones in line. I have got to think about this. Maybe fit a 2 in diameter section of pipe with the air stones in it. We may have something here. As some of you may know, I had a pretty large airstone skimmer with 6 3 inch AES fine air stones before this skimmer. I added a OR 3700 to RC the water in the chamber from a suggestion here on ReefCentral. It improved the bubble quality tremendously, almost night and day!
hahnmeister
In Memoriam
":han, you keep refering to "seeing more" of this or that. Though it is a nice thought, it just does not happen as the norm. You keep assuming that manufacturers refine every (or for that matter ANY) aspect of their designs. They in fact do very little refining of anything. They do the bare minumum that works to get products moved off the shelf."
-BeanAnimal
Hey, what ever happened to the 'idea' that the venturis that came with the pumps were the best possible design for the intake?!?! Lol. I would assume that the maximum mixture was already achieved with the pump and venturi... and even if not, a simple valve on the water intake would hemp maximize air intake while minimizing water intake (in a non-forced air system). This is all just in reference to the venturi on the intake of course... but aside from tampering with the pump's impeller design, boring out shrouds, enlarging inlets/outlets... the intake venturi/valve setup is what is going to determine the maximum intake mixture of water or air (what else possibl y is there?). In another thread I was told I was wrong for suggesting that there were better options (adjustable intake valve options) for mixing pump intakes other than the ones that have been designed for eheims, oceanrunners, etc.
Im not disagreeing with you Bean, but even if some MFG hasnt achieved maximum performance/tweaking for a venturi intake, with these DIY skimmers, I would assume that there would be a valve on the air and the water intakes before the venturi... what more could you ask for assuming that the venturi is as 'fluiddynamic' as needed? Im just going with the idea that water is the independent variable (you can have less or more flow of air and still have the same amount of water with just the venturi.. of course more air means less water throughput), and air is the dependent variable (you cant turn down the water throughput and expect to get more suction of air). Going by this, I can see what you are saying... perhaps the venturis and intakes arent 'tweaked' 100%, but assuming that they have been, and for what we are trying to achieve here, we could assume that the only way we are going to get more air sucked in is with more water passing through that intake (increasing velocity, lowering pressure, etc... you cant create more suction in the venturi if you decrease the water volume/velocity assuming everything else it at its max).
On a side note... I tried that whole 'multiple small inlets' vs. 'large gulp of air' thing this afternoon because I had a hunch. With the air blower (a big old sweetwater from my african cichlid importing/breeding days) on the same setting (er, valve positioning), the amount of air that the pump could intake didnt change from one to the other. With a single larger intake, the water just sweeps away the air faster... with multiple inlets (I made 8 x 3/16" inlets every 45 degrees around the pipe, the air is just swept away from multiple points. I did the intake in acrylic so I could see. The maximum amount of air before my Oceanrunner choked didnt change... It seems that the amount of air is all that matters no matter how its fed when you have a forced air system. The water just flows too fast and once it gets to the impeller intake, it makes no difference... in a nanosecond, its all blended anyways. There might be some sort of relationship here, but it doesnt seem to be significant enough to notice.
Another thing to keep in mind... remember Deltec suggests turning back many of their eheim 1260 powered skimmers by 20-30%. Restricting the air intake increases performance in this case. Trying to get more air into some of skimmers might be overkill in the same respect. Im all for tinkering, but two OR3700s on my 8x8x48" tall skimmer is looking like its all I need. When I tried injecting more air, the turbulence went up.
-BeanAnimal
Hey, what ever happened to the 'idea' that the venturis that came with the pumps were the best possible design for the intake?!?! Lol. I would assume that the maximum mixture was already achieved with the pump and venturi... and even if not, a simple valve on the water intake would hemp maximize air intake while minimizing water intake (in a non-forced air system). This is all just in reference to the venturi on the intake of course... but aside from tampering with the pump's impeller design, boring out shrouds, enlarging inlets/outlets... the intake venturi/valve setup is what is going to determine the maximum intake mixture of water or air (what else possibl y is there?). In another thread I was told I was wrong for suggesting that there were better options (adjustable intake valve options) for mixing pump intakes other than the ones that have been designed for eheims, oceanrunners, etc.
Im not disagreeing with you Bean, but even if some MFG hasnt achieved maximum performance/tweaking for a venturi intake, with these DIY skimmers, I would assume that there would be a valve on the air and the water intakes before the venturi... what more could you ask for assuming that the venturi is as 'fluiddynamic' as needed? Im just going with the idea that water is the independent variable (you can have less or more flow of air and still have the same amount of water with just the venturi.. of course more air means less water throughput), and air is the dependent variable (you cant turn down the water throughput and expect to get more suction of air). Going by this, I can see what you are saying... perhaps the venturis and intakes arent 'tweaked' 100%, but assuming that they have been, and for what we are trying to achieve here, we could assume that the only way we are going to get more air sucked in is with more water passing through that intake (increasing velocity, lowering pressure, etc... you cant create more suction in the venturi if you decrease the water volume/velocity assuming everything else it at its max).
On a side note... I tried that whole 'multiple small inlets' vs. 'large gulp of air' thing this afternoon because I had a hunch. With the air blower (a big old sweetwater from my african cichlid importing/breeding days) on the same setting (er, valve positioning), the amount of air that the pump could intake didnt change from one to the other. With a single larger intake, the water just sweeps away the air faster... with multiple inlets (I made 8 x 3/16" inlets every 45 degrees around the pipe, the air is just swept away from multiple points. I did the intake in acrylic so I could see. The maximum amount of air before my Oceanrunner choked didnt change... It seems that the amount of air is all that matters no matter how its fed when you have a forced air system. The water just flows too fast and once it gets to the impeller intake, it makes no difference... in a nanosecond, its all blended anyways. There might be some sort of relationship here, but it doesnt seem to be significant enough to notice.
Another thing to keep in mind... remember Deltec suggests turning back many of their eheim 1260 powered skimmers by 20-30%. Restricting the air intake increases performance in this case. Trying to get more air into some of skimmers might be overkill in the same respect. Im all for tinkering, but two OR3700s on my 8x8x48" tall skimmer is looking like its all I need. When I tried injecting more air, the turbulence went up.
