Matt Matt Posted December 10, 2019 Share Posted December 10, 2019 What is the highest pressure blower before becoming a pump? I want to deliver more CFM through a smaller line. There are centrifugal, then the roots blower, Then there is turbine, then there is the mixture of centrifugal with a prop intake. Then there is the good old regular vacuum fan. If higher psi is required to overcome static pressure, which fan would you use? Ideally, I’d like to pull/push 200-300 CFM through a garden hose 10 foot long. Link to comment Share on other sites More sharing options...
Glenn Posted December 10, 2019 Share Posted December 10, 2019 How much CFM and pressure is needed on the output end of the hose? What are the dimensions of the hose you are using, both ID and length? Link to comment Share on other sites More sharing options...
timgunn1962 Posted December 10, 2019 Share Posted December 10, 2019 It sounds to me like you probably don't understand the physics well enough to be asking the right questions. The lines between blowers and pumps can be blurry at best.It's certainly not as simple as changing from one to the other at a defined pressure. "200-300 CFM" is a very wide range when considering the pressures needed to drive flow through a tube. I'd suggest an online search to find the catalog for "Rotron Regenerative Blowers" and read the technical stuff near the back. It'll either give you some answers or will give you a better idea of the appropriate questions. There is a "friction loss per foot of tubing" chart that should prove particularly instructive. Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted December 10, 2019 Share Posted December 10, 2019 Another thing, what do you intend to use the blower for? Link to comment Share on other sites More sharing options...
Latticino Posted December 10, 2019 Share Posted December 10, 2019 Lets assume you are discharging into "free air" at the end of a 10' long standard 3/4" garden hose. If you are attempting to move 250 CFM of standard temperature and pressure air (for density and viscosity) through said hose, the friction loss will be on the order of 2,620 inches of water gauge (or around 95 PSI). That is not including entry and exit losses, which will certainly be present, or any residual pressure you might need at the termination (for blasting through a coal grate or pile of fuel and clinker). I believe the term you are looking for is an air compressor, not a pump, but finding one with those unusual flow characteristics may be problematic (a typical 5 HP dual stage compressor will move around 15 CFM at 95 PSI, you are talking about a bank of large compressors). High pressure blowers exist that will move 250 CFM, but will struggle greatly with the over 260" of loss. Unfortunately I don't deal with compressed air design all that much, so can't advise you further, but my instincts say that it will be a remarkably inefficient and costly method of transporting air for a forge, not to mention issues with water vapor. Why are you considering this method of air transport? Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted December 10, 2019 Share Posted December 10, 2019 Matt Matt, we still have no idea where in the world you are located, hence the suggestion to edit your profile to show your location. You may be surprised how many members are near you to help with your problem. Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 10, 2019 Share Posted December 10, 2019 I worry about the strength of the hose! Link to comment Share on other sites More sharing options...
Latticino Posted December 10, 2019 Share Posted December 10, 2019 OK, I used a different sizing tool, for air at higher pressure in pipe rather than very small diameter duct (25 PSI instead of standard temperature and pressure). Air is compressible, so it makes a big difference. Using this calculator, and air at 25 psig, I get a loss for a 10' section of 3/4" pipe of only 14 psi. Like I said, I don't do much with compressed air design. Might be feasible with a compressor, though I also would be concerned about the strength of the hose, and stand by my statement that it is a extremely inefficient option. Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 10, 2019 Share Posted December 10, 2019 As air is compressible; long runs of hose/pipe store energy and failure tends to be messy . Also hose that is fine brand new out of the box can fail catastrophically after exposure to sun and having the car drive over it. Link to comment Share on other sites More sharing options...
Matt Matt Posted December 10, 2019 Author Share Posted December 10, 2019 OK, I thought it might’ve been a little easier. I am in Ontario Canada. I am currently using a small four stage turbine. Pumping through three-quarter(ID) garden hose 25 foot long then teeing into two 10 foot half-inch (ID) flexible food grade hose nylon reinforced. These feed my burners. Currently I am getting 45ish CFM from each burner. At the exit of the turbine I’m getting 150 CFM. With all that hose, I have lost 60cfm. My turbine creates 7 psi measuring it as a closed system. I could remove the 25 foot of garden hose. But, I wanted to start to keep an eye on the used market for something more powerful. It does look like a ring compressors might be what I need. Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 10, 2019 Share Posted December 10, 2019 Or build naturally aspirated burners and skip the compressor purchase and run expense. Link to comment Share on other sites More sharing options...
timgunn1962 Posted December 10, 2019 Share Posted December 10, 2019 Try increasing the size of the hoses. If you can double the diameter of the long section, the area will increase by a factor of 4 and the pressure loss will go down dramatically (the physics gets complicated, but a first approximation is that the pressure loss varies as the square of the velocity, so you'd get something of the order of one sixteenth of the pressure loss along the same length at the same flowrate). Shorten the hose and the pressure loss will vary with the length (as a first approximation). Ten feet of 1 1/2" hose will give "about" one fortieth of the pressure loss of your twenty-five feet of 3/4" hose. If you go for 1 1/2" hose upstream of the tee, get the tee as close as possible to the burners and use the 3/4" hose (that you already have) between the tee and the burners, things will probably get a lot more manageable. Link to comment Share on other sites More sharing options...
Matt Matt Posted December 10, 2019 Author Share Posted December 10, 2019 1 hour ago, ThomasPowers said: Or build naturally aspirated burners and skip the compressor purchase and run expense. I’m using Diesel then switching to vegetable oil. The air atomizes the oil’s and for combustion. Thanks Timgunn for your suggestions. I’ll try them out. Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 10, 2019 Share Posted December 10, 2019 OK then it's the pressure that's important! Can you add extra air from a more easily sourced blower to the atomized spray produced by a lower amount of high pressure air in a regular air hose?? Don't forget that regular hose will degrade from the oils used in the compressor. Link to comment Share on other sites More sharing options...
Matt Matt Posted December 11, 2019 Author Share Posted December 11, 2019 After timgunn first post I started searching the local classifieds for ring compressors and Regenerative Blowers. A guy just emailed me back saying “I could come pick up for free, one of his damaged ones”. He mentioned to rebuild it would cost $800 to $900. It has a 4.6 kW motor which is close to 6 hp. Maybe I have a rebuild in my near future. I’ll keep my fingers crossed. Link to comment Share on other sites More sharing options...
Matt Matt Posted December 11, 2019 Author Share Posted December 11, 2019 Hopefully it’s not a burnt out motor. Link to comment Share on other sites More sharing options...
Latticino Posted December 11, 2019 Share Posted December 11, 2019 13 hours ago, ThomasPowers said: Can you add extra air from a more easily sourced blower to the atomized spray produced by a lower amount of high pressure air in a regular air hose? That is an excellent suggestion. Pretty easy to get a small pancake compressor to use to atomize the fuel source then tie in a small "squirrel cage" blower to bring in the required combustion air. And running electric 25' is easy as well. You can even keep your oil storage tank remote if you elevate it and gravity feed the feed line. 15 hours ago, Matt Matt said: At the exit of the turbine I’m getting 150 CFM How are you measuring that accurately? Did you do a multipoint traverse of a fixed size chamber with a hot wire anemometer or pitot-static probe and manometer gauge? Link to comment Share on other sites More sharing options...
Buzzkill Posted December 11, 2019 Share Posted December 11, 2019 As others have indicated, use low volume high pressure air (i.e. air compressor) to atomize the fuel and use high volume low pressure (blower) to provide combustion air. For a short time I ran a used oil system which I started up on diesel or kerosene and then switched to the oil when the forge was hot. I hooked up the compressor to run the siphon nozzle which both pulled in the fuel and atomized it and I used an old blower off a power vent hot water heater to provide combustion air. That's a much easier and more effective solution than trying to use one air source for both purposes. Link to comment Share on other sites More sharing options...
Matt Matt Posted December 14, 2019 Author Share Posted December 14, 2019 Is there a replacement for displacement??? What is it? Is there a happy medium? I picked up the blower today and it looks like it needs a new bearing, or two and and maybe a new winding. anyone want to help with windings??? I’m sure there’s probably a motor guy here? If I rewind the motor, is there an easy DIY? Link to comment Share on other sites More sharing options...
Anachronist58 Posted December 14, 2019 Share Posted December 14, 2019 How about a picture of this blower? I have never heard of an "easy" rewind. Was the blower free, and if not, can you get your money back? 10 hours ago, Matt Matt said: Is there a replacement for displacement??? What is it? Is there a happy medium? Not sure what you are asking here, but if you are asking if you can bypass the above two-system advice (high pressure/low volume + low pressure/high volume), the answer would be no. Robert Taylor Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted December 15, 2019 Share Posted December 15, 2019 17 hours ago, Matt Matt said: is there an easy DIY? Nope... Link to comment Share on other sites More sharing options...
Matt Matt Posted December 15, 2019 Author Share Posted December 15, 2019 10 hours ago, Anachronist58 said: How about a picture of this blower? I have never heard of an "easy" rewind. Was the blower free, and if not, can you get your money back? Not sure what you are asking here, but if you are asking if you can bypass the above two-system advice (high pressure/low volume + low pressure/high volume), the answer would be no. Robert Taylor Sure thing. Here is the broken blower. I got it for free. I am currently using two mini torches. I have a mini 4 stage turbine that seems to do the trick. You can see it in the background of this video (it is blue). What I referred to as the little pipe bomb air compressor in the video, it is just giving head pressure to the vegetable oil tank and diesel oil tank. I am burning about 2.8 gallons per hour with the flame just slightly creeping out the top. I am currently using the turbine to deliver combustion air, Which seems to do a decent job atomizing too. Link to comment Share on other sites More sharing options...
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