Friction Steam Boiler

[Alana]

@ Jetijs

thanks for sharing your very impressive video. I think I must revoke my scepticism about Tesla turbines.
As I have seen in your video the engine runs on 60 PSI and about 26000 RPM. But how many cfm does the engine needs? Have you ever mesured the ft lb?

Alana

[rickoff]

Re: Second Tesla Turbine test

Hi Rick
My tachometer works also without a reflective tape, it just detects when the laser beam goes right through the turbine and when it is hindered by the spokes. Also the spokes are rather shiny already by themselves. So far looks like it is showing the RPM's correctly.

here is the new video:
YouTube - Tesla turbine. Test 2

Thanks for the second test video, Jetijs. The turbine really does spin up quickly now from a standstill. The torque looks to be quite substantial, as shown by the force needed to stop rotation after the air supply was cut off. Best to be careful in using your fingers that way!

I assume that you performed this test after installing the rubber spacers, but before eliminating the wobble that you noticed, is that correct?

Was there any particular reason why you doubled the air pressure for this test? Was the 26,000 rpm reading the actual shaft rpm, or a divide by three spoke reading as in your previous test? I assume that you only brought the turbine up to what you felt was a safe rpm level, and that it could go considerably higher if vibration was not a worry.

Like you say, there is still room for improvement, but the results thus far are very encouraging.

Thanks again,

Rick

[Jetijs]

Thanks Rick
You are right, this test was done with the rubber spacers and the vlbbling was still there. This made the whole table vibrate at max speed in the video. That tacho reading needs to be divided by 3, because of the three spokes, so in the video tha max speed was just under 10k RPM. There was no special reason for using 60PSI, my friend just turned it that way, but I am able to get the same RPM's even with 30 PSI, it just takes a little longer. I am sure that with correct spacers and perfectly aligned blades, there wont be any considerable vbibrations and I will be able to get higher speeds. Aso the air intake is still far from perfect, because the air is still not distributed evenly, it is flowing mostly to the middle part of the blades. The torque is quite good, because it is impossible to stop the shaft by hand at those speeds. The shaft gets hot very fast and you can burn your fingers. I think that gearing the speed down to some usable RPM's could be advisable, as we don't need that much speed for the frictiol steam boiler, also reduced speed will increase the torque. So far it seems that this thing has quite a potential and it is well worth to build a serious model with metal casing.


Alana, I don't have any equipment to measure the torque of this turbine. Will need to figure something out

[rickoff]

Re: Turbine torque

I think that gearing the speed down to some usable RPM's could be advisable, as we don't need that much speed for the frictiol steam boiler, also reduced speed will increase the torque. So far it seems that this thing has quite a potential and it is well worth to build a serious model with metal casing.


Alana, I don't have any equipment to measure the torque of this turbine. Will need to figure something out

Jetijs - you might take a look at post #306, where I showed a method for figuring horsepower and torque. Basically, it simply amounts to bringing the turbine up to speed, and then using a braking device to apply a constant anti-rotational force just enough to bring the rotational speed down to a steady 5252 rpm, which is the standard used for dyno tests. Leaving the braking force at the applied level, you then cut the air supply and allow the turbine to stop. Once stopped, place a torque wrench on a bolt at the center of the turbine shaft and measure the force required to begin rotating the shaft. Convert this reading to ft/lbs, and the result will equal both braking horsepower and torque for the 5200 rpm standard. Of course the 5200 standard is better suited to ICE's, where that rpm level, on average, is right about where you would be putting out best torque per rpm. In an ICE, torque increases as rpm increases between zero and 6,000, but typically (for the average automobile on the road today) will reach a high point in a graphed torque curve somewhat below 6,000 rpm, and thus the reason for the 5200 standard. Conversely, in a steam engine or turbine, torque per rpm is greatest when closest to the zero rpm level, and that is why a Tesla Turbine could be used to power an automobile without need of a transmission. This same factor works in our favor when turning Lloyd's friction roller at relatively low rpm's. This, of course, doesn't mean that the turbine will have low overall torque at high rpm. It just means that the torque curve is backwards from an ICE. With the turbine, torque gain diminishes as speed increases, but there is still gain. There will be higher overall torque at 10,000 rpm than there is at 1,000 rpm, for example, but not 10 times as much.

Just some food for thought......

Rick

[InstrumentGuy]

Hi Paul,

...
We could regulate speed of the prime mover simply by closing the intake as necessary, and the drop in speed would reduce the amount of frictional heating. That seems easy enough, but it would cause the vessel to go much higher with internal pressure until the temperature can drop, and you would then need to release that overpressure quickly, or have a dangerous situation. Of course you would have pressure relief valving in your system to handle that scenario, but it would result in wasting of steam potential.
...
Rick

Hi Rick, I've been following the discussion on the friction steam boiler for a while and plan to try it out myself soon. I'm an instrument mechanic in the oil patch and could use different devices to control the intake of the prime mover, but I was thinking that the simplest may be to control vessel steam pressure instead of temperature. Connect the steam pressure to a cylinder in which a piston works against an adjustable spring, with the stem connected to a valve. As steam pressure increases, it overcomes the spring, pinching the valve which is inline with prime mover supply. Automation!

[rickoff]

Reply to Instrument Guy:

I was thinking that the simplest may be to control vessel steam pressure instead of temperature. Connect the steam pressure to a cylinder in which a piston works against an adjustable spring, with the stem connected to a valve. As steam pressure increases, it overcomes the spring, pinching the valve which is inline with prime mover supply. Automation!

Hi Instrument Guy, and welcome to our thread. Your idea does have some merit as a steam regulation means, and will definitely work (initially, at least) to maintain an even speed of the prime mover even though vessel pressure increases. There will be a limit as to how much overpressure the cylinder can take in, and unless the speed of the prime mover is reduced, or the frictional force reduced, then the overpressure problem will continue. Our primary objective is to maintain a constant rpm level of the prime mover, so we don't want to slow rotation down in order to control steam pressure. Another concern is that the piston would have to be of sufficient diameter, and the cylinder of sufficent length, to contain any overpressure created in the vessel. Pinching off flow to the prime mover will initially mean that the cylinder will also have to be sufficient to accept the flow rate that had been going to the prime mover, but which has now been reduced. Of course a waste port could be incorporated in the cylinder so that it would act as a pressure relief if the piston was pushed to a defined limit within the cylinder. We do want to avoid any wasting, though, unless necessary as an emergency measure.

I do like your idea, and would suggest adopting it as a momentary means of regulating the speed of the turbine at a constant level during slight variations in steam pressure. This could work beautifully in conjunction with a system to relieve frictional force.

Thanks for your input, and best regards to you,

Rick

[rickoff]

Instead of having a water dripper used for the steam, couldn't we build the roller with paths for direct water circulation and then use a rotating joint to deliver/retrieve water to/from the roller? This would have the effect of capturing the heat being created in the roller while simultaneously keeping the roller and bearings from overheating. Being that there would be no air gaps to lose heat or steam pressure, wouldn't we be able to make it more efficient?

Hi everwiser,

Yes, you could certainly circulate water through the friction roller, or through a hollow pipe shaft on the original vertical rotor design, and this method was discussed as an option in post #45. You will find a link near the bottom of that post that shows rotary union couplers of the type that would be needed. I do believe however, that this method would best be used in a hot water only system, for creating domestic hot water and/or baseboard heating, where steam isn't needed. It is going to be very difficult to beat Lloyd's drip system of creating on-demand steam, which is already super efficient.

As to bearing overheating, this won't be a problem if you circulate cooled oil through the bearings by means of a system such as shown in the diagram of my post #93. That diagram shows the oil circulated through a radiator to provide cooling while also providing heat to the room where the friction device is located. Alternatively (if one does pursue steam generation), the radiator could be a heat exchanger within the cool water hopper tank to preheat the water before it is released to the water reservoir tank. If you do go with a hot water only system, and rotary unions, I believe that you will find it quite efficient. Just remember that the water used for baseboard heating must not have any potential to mix with and contaminate your domestic hot water storage.

Best wishes to you,

Rick

[brenie]

Hello Jetijs, just watched 2nd tela test, great.
Many thanks, will nominate you for next years Osca awards!

Regards Bren.

[Jetijs]

Thanks Bren

[rileydad48]

Rick...
Lloyd's response to your questions, reguarding HP and torque.. 8lbs of torque using 14 pieces of wood.. that is amazing.. seems like it will be difficult to slow a Tesla turbine's speed down enough to spin the 8"roller in my idea to the correct rpm's.. I think My design may have to change.. Might have to sepperate the generator and the turbine from the Boiler and use a belt system to obtain the correct rpms for both. I can see the boiler producing an excess of steam.. at these figures.. my estimation of 12-15hp to run the whole thing ..might be somewhat high.. or as Rick said earlier" over kill"

Paul

[rickoff]

A note about editing posts:

Hi everyone,

I notice that some of you have had trouble when attempting to edit a post. Of course the best way to avoid an edit is to click the "Preview this message" button, and proofread it before you post it by clicking the "Save" button. There are times, though, as I can well attest to, that you still may find a misspelled word or typo later, or find that you need to add some further information to clarify something you have stated. Clicking the Edit button will allow you to perform an edit, but you will probably run into problems when you try to save your edit. This is particularly true if anyone has already posted a message after the one you are trying to edit, or if someone is reading the message you are attempting to edit. To avoid these problems, do the following:
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4. Once you have everything as you want it, click the Save button.

The Advanced mode forces the system to immediately accept your changes upon saving them. If you should want to Delete a post for any reason, just use the Advanced mode, then scroll up above the Edit Post window and you will see a smaller Delete This Message area. Click to bullet the "Delete Message" option, then click the Delete This Message button below that. Note that the default bulleting is "Do Not Delete Message," which pevents a message from being accidentally deleted if you click the Delete This Message button by mistake. To actually delete the post, the bullet must be in the Delete Message option. Some reasons for deletion may be to remove a duplicate post, to remove a post that may be off topic or irrelevant, or to withdraw a statement which may be incorrect and may tend to confuse readers.

So there you have it, and I hope this will be helpful to everyone.

Best wishes to all,

Rick

[rickoff]

Reply to paul:

Rick...
Lloyd's response to your questions, reguarding HP and torque.. 8lbs of torque using 14 pieces of wood.. that is amazing.. seems like it will be difficult to slow a Tesla turbine's speed down enough to spin the 8"roller in my idea to the correct rpm's.. I think My design may have to change.. Might have to sepperate the generator and the turbine from the Boiler and use a belt system to obtain the correct rpms for both. I can see the boiler producing an excess of steam.. at these figures.. my estimation of 12-15hp to run the whole thing ..might be somewhat high.. or as Rick said earlier" over kill"

Paul

Hi Paul,

One thing to keep in mind is that the Tesla turbine can run well at any speed between minimal and maximum. You don't have to utilize any more steam pressure and volume than is absolutely necessary to maintain the roller speed if using a direct drive, and this would probably prove to be the most efficient drive method. If you have a surplus of steam, or the capacity to produce it, you can add on a motor-generator using either of these methods:
1. If you use an induction motor-generator rated at 1800 rpm, you can run it, and the friction roller, in direct drive mode at 1855 rpm and generate the full hp rating of the motor in electric production, or 746 watts per horsepower. Since the motor-generator is about 85% efficient at producing power, that means you will be using 1.18 hp of the turbine's total hp output to drive a 1 hp generator. Adding that power requirement to the turbine's output will create drag, just as the friction roller will, and the turbine's output rpm will want to drop. So you compensate by increasing steam pressure and volume to keep the shaft rpm at 1855.
2. You could run your turbine at a higher speed, and drive the friction roller and generator separately using drive reduction ratios. This would be accomplished either with reduction gearing, or with appropriately sized pulleys and drive belts. Both these methods add additional expense vs the direct drive method, and they also add some undesired attributes. The belt and pulley method, because of the belt tension, places high loads on the adjacent bearings of both the turbine shaft and the generator. Gearing produces noise and creates drag. The turbine can breeze along at 5565 rpm while driving the frictional roller and generator with relative ease using 3 to 1 reductions that produce high torque, but will this be the most economical and efficient means of operating the turbine? Maybe not. Keep in mind that the turbine creates the greatest torque per rpm at relatively low shaft speeds, which tends to negate the need for high rpm and reduction driving. Unlike an ICE, the turbine does not "strain" to turn the driven accessories when load nears capacity. The turbine either turns or it doesn't, and no damage results from it slowing down or not turning. That in itself is a huge plus over an ICE.

It's not unlikely that you may be able to operate a 1 hp generator with the surplus steam available from Lloyd's friction device. As stated, in the #1 example above, 1 hp = 746 watts. Now 746 watts may not seem like a lot of power, but consider that you could produce that amount 24 hours a day, all month long. In kilowatt/hrs that would equal .746 x 24 x 30, or 537 kwh. Now I don't know about your electric usage, but mine for the period of mid November to mid December was 502 kwh. I know that someone reading this will start thinking, "well that looks fine in terms of the numbers, but your actual power needs vary quite a bit at certain times of the day. When you are sleeping, only your clocks and intermittent items, like your refrigerator, actually run, so your use would be lowest. What do you do with any excess power during the night? And what about mealtimes, when you may be using a toaster, a microwave, or an electric oven? And how about a clothes washer and dryer, a dishwasher, etc. The 746 watts wouldn't be enough to run a toaster, or even some hand held air dryers, let alone anything in addition to that." Well, that is quite true - but here's the solution that lets you make sense of it all. Just by plugging the induction motor generator into a household electric receptacle, the generated electricity becomes available for your needs. When needs are low, the excess will make your electric meter run backwards. It's like putting money into the bank - you put it in to draw it out only when you actually need it. It's just that instead of banking money, you are banking kilowatt hours that can be drawn and used whenever the need arises - like mealtimes, or laundry time, etc. Now does this make sense, or what?

You see, it really is possible to greatly reduce your monthly electric bill with just a 1 hp-motor generator while staying connected to the grid. Most electric companies do set a "minimum charge" of about $10 to $15 per month when you use less than the minimum kwh that would result in that fee. Therefore, it is normally not possible to entirely eliminate your electric bill by this method. You have to admit, though, that $10 to $15 a month to stay grid tied really does have its advantages, and is cheap insurance.

Good night, and best wishes,

Rick

[brenie]

Thanks Rick, good info as usual.
One message deleted, I shall now nominate Jetijs for only One Osca!

Regards, Bren.

[gene gene]

Hi Rick,
Thanks for all your help & sharing of your knowledge. (Great Forum)
My short time use of a computer has been mostly surfing the web and ridding the renewable & free energy wave. My posts here are my first.
I live in a small town in N. Wisconsin and being 1 1/2 hrs to a large town is hindering my 1/4 scale Lloyds heater build. However there are probably 12-15 sawmills within 10 miles of my home and green oak is plentiful. If anyone is close to finnish on a build, and has a need. I would like to offer to ship a few 1/4 or 1/2 scale 1x1x6" or 2x2x12" pieces for testing. Just pay shipping. I also travel to Ia. & Ill. a number of times every year, and could maybe hook up if someone needs full size for testing.I would like to see another build.
We have a good number of retired folks (on a fixed income) in our area, many who spend alot of the winter in one room with an electric heater just to save money on their gas or oil bill.
I believe I have finally found a solution to this need, at a fraction of the cost of solar or wind.
Rick, one question. Didn't Tesla latter have an adjustable steam inlet or jet for his turbine, and might that be used to control RPM's of turbine?
Thanks to all,
Gene Gene

[boguslaw]

What about resin from wood ? Did anobody checked the electrical properties of this substance ? Maybe the wood which Loyd is using has special electrical properties which add energy to friction by induction currents. Is there a way to measure induction currents inside metal from distance ? THAT would be a proof of overunity by additional energy of electrocstatic flux being a current in case of rotation around the same metal surface.