DIY Tesla Impulse Turbine

[The Ignoble Troll]

Those couplers should have an rpm/temp rating for the spiders iirc. Unless they are random internet ones

 

[Toymaker]

Those couplers should have an rpm/temp rating for the spiders iirc. Unless they are random internet ones

The couplers were purchased via AliExpress :Plum Coupler
The only specs given are diameter, length, and shaft size,....and the spider is Polyurethane.

 

[The Ignoble Troll]

The couplers were purchased via AliExpress :Plum Coupler
The only specs given are diameter, length, and shaft size,....and the spider is Polyurethane.

@nerd100 probably has the right idea then, going all metal.

 

[Richard Hed]

Steam flow rate was 0.83 LPM (Liters Per Minute) at just over 100 C and at nearly zero pressure. The coupler melted before I had a chance to measure RPMs and the voltage reading was made after RPMs had already dropped off. This test ended too quickly to have provided adequate data.

I THINK the coupler melted from heat created by friction as the stainless steel TT drive shaft spun inside the aluminum coupler, after the steam heat loosened the connection. I don't believe the steam heat alone melted the coupler's plastic spider. I'll tighten the coupler onto the shaft a bit tighter for the next test,...hopefully, that will be enough.

Both TT bearings are full ceramic which run "dry" (no grease or oil).

Wait a minute, wait a minute. .83 LPM? you must mean .083 LPM? at .83 you would have a veritable explosion. You'd need a huge boiler.

 

[Toymaker]

Wait a minute, wait a minute. .83 LPM? you must mean .083 LPM? at .83 you would have a veritable explosion. You'd need a huge boiler.

Compared to most boilers found on HMEM, my 10" diameter x 13" long monotube flash boiler, containing 30 feet of 5/8" diameter copper tube, is huge.

The following video was taken just before I redirected steam flow into the Tesla turbine via a 3-way valve. Midway through the video I focus in on the K24 flow rate meter (Blue face plate) which measures feed water into the boiler and is displaying 6.0XX liters total flow (big number) and 00.83 to 00.86 LPM (bottom smaller numbers). So, unless the K24 flow meter is off by a factor of 10, which seems unlikely, the boiler is indeed making 0.83 LPM steam at a 53% power setting.

 

[Steamchick]

Hi, Can you explain Boiler temp out at "91", and 31psi? - sounds like hot water, not steam. If inlet pressure is 35psi, and outlet 31psi, then the inlet pump is providing the pressure, not the burner "adding enthalpy"(or something...??) if my thermodynamics is right? - SO I am not sure what this is telling me. (I stopped video at 15 seconds run-time).

Thanks,
K2

 

[Toymaker]

Hi, Can you explain Boiler temp out at "91", and 31psi? - sounds like hot water, not steam. If inlet pressure is 35psi, and outlet 31psi, then the inlet pump is providing the pressure, not the burner "adding enthalpy"(or something...??) if my thermodynamics is right? - SO I am not sure what this is telling me. (I stopped video at 15 seconds run-time).

Thanks,
K2

I still haven't been able to set the temp and pressure sensors to display accurate readings; view them as +/- 30.
The video clearly shows steam shooting out of the 16mm copper tube at the end of the video, which shows open flow steam with no pressure and no water sputtering out along with the steam. After the boiler reaches this level of steam output, using a manual 3-way valve, I redirect the steam flow from the copper tube, into the Tesla turbine.

BTW, I didn't have a problem with water building up inside the housing; the turbine spun up quickly with little to no hesitation,...before the coupler failed.

Luck permitting, the steam gods will shine upon me during the next test and allow me to get some good results and good video

 

[Steamchick]

Thanks, I understand!
Do you have a mechanical pressure gauge you can affix? - may be within a few %...
And maybe rest some soft solder on the pipe - when it reaches melt temperature you have a control standard for resetting your fancy digital thing?
K2

 

[The Ignoble Troll]

The couplers were purchased via AliExpress :Plum Coupler
The only specs given are diameter, length, and shaft size,....and the spider is Polyurethane.

Probably a working temp around 75°c according to some generalized data sheets.

 

[Toymaker]

Thanks, I understand!
Do you have a mechanical pressure gauge you can affix? - may be within a few %...
And maybe rest some soft solder on the pipe - when it reaches melt temperature you have a control standard for resetting your fancy digital thing?
K2

I have the liquid filled dial guage shown in the video in post #305 at 11 sec in, and I have been using that guage as my "gold standard" for pressure values, for adjusting pressure sensor values. But the real problems are electrical noise generated by the 3 motors, the two DC to DC power supplies I use to drop the 36 vdc down to 12 vdc and 5 vdc, and the very small voltages from the sensors which represent pressure and temperature.
The Arduino micro computer I'm using as the ECU (Engine Control Unit) can only use 0 to 5 volts dc to read the full pressure range of 0 to 500 psi. The range on the pressure sensors is 0 to 1000 psi, meaning their 5 volt output indicates a 1000 psi pressure, a 2.5 volt reading represents 500 psi, and 0.5 volt reading represents 100 psi.

The 35 & 31 psi readings seen on the display during the test run meant the two pressure sensors were sending out 0.175 and 0.155 volts respectively. Reading those small values accurately when the electrical noise level is 0.200 to 0.300 volts is challenging at best, and impossible at worst.

 

[Toymaker]

Probably a working temp around 75°c according to some generalized data sheets.

Well, that's not good,... as I suspect the stainless shaft will always rise to at least 100° C.

The next test run will be interesting,...I replaced the melted spider with quick-set epoxy, essentially making a replacement spider using epoxy. If this too fails, I will use either a high temp epoxy or high temp silicone.

 

[Nerd1000]

I have the liquid filled dial guage shown in the video in post #305 at 11 sec in, and I have been using that guage as my "gold standard" for pressure values, for adjusting pressure sensor values. But the real problems are electrical noise generated by the 3 motors, the two DC to DC power supplies I use to drop the 36 vdc down to 12 vdc and 5 vdc, and the very small voltages from the sensors which represent pressure and temperature.
The Arduino micro computer I'm using as the ECU (Engine Control Unit) can only use 0 to 5 volts dc to read the full pressure range of 0 to 500 psi. The range on the pressure sensors is 0 to 1000 psi, meaning their 5 volt output indicates a 1000 psi pressure, a 2.5 volt reading represents 500 psi, and 0.5 volt reading represents 100 psi.

The 35 & 31 psi readings seen on the display during the test run meant the two pressure sensors were sending out 0.175 and 0.155 volts respectively. Reading those small values accurately when the electrical noise level is 0.200 to 0.300 volts is challenging at best, and impossible at worst.

You can use some RC filters to get rid of the noise.

 

[Toymaker]

You can use some RC filters to get rid of the noise.

I've already tried hanging 1000uf caps and various resistor values onto the power supply outputs with very little success. I've just ordered some LC filters made for power supply noise suppression,...hopefully these will work