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  • buenijo's Avatar
    Yesterday, 05:53 PM
    I came upon a video of someone testing the same alternator that I selected for my steam engine project. This is the 48v model. There is another unit with different windings suitable for a 24v battery. Both units will operate at around 1500 rpm while charging. Based on comments, the amp rating is likely generous. He suggests no more than 1500 watts continuous and likely 1000 watts to ensure no overheating. Not terribly surprised. China is very bad about inflating specs.
    44 replies | 24417 view(s)
  • buenijo's Avatar
    02-03-2025, 04:47 PM
    I recently came across several compact car conversions on YouTube where the stock engine was replaced with a 670cc V Twin Predator engine via a centrifugal clutch. The result is essentially a large go cart. A subcompact car is able to reach modest highway speeds on level ground - with 40-50 seconds required to get up to speed. Adding a drive motor in a parallel hybrid configuration to significantly boost torque would not be terribly difficult. This configuration can provide several benefits. First, the vehicle can be driven by the motor, the engine, or BOTH. The battery capacity required is modest, and this relatively small battery system could fit in the engine compartment. The engine could power the vehicle on level ground up to modest highway speeds with the motor available for torque boosts as required for more rapid acceleration and/or hill climbing. Furthermore, the motor can be configured to act as a generator to charge the battery. For example, assume the drive motor alone is capable of driving the vehicle up to 60 mph when provided with full battery pack voltage. With the engine geared to exceed this speed, then the motor rpm can increase to cause the motor to act as a generator to recharge the battery (this is inherent in this motor design). (*) Cost for parts for the drive system would be on the order of $5000-7000. The main benefits in my mind are the ability to eliminate fuel consumption on short trips, and the ability to maintain the vehicle indefinitely with relatively trivial maintenance (small engine maintenance is straightforward and the EV drive components are highly reliable). Also, such a conversion has the potential to show impressive fuel economy in highway driving as the engine would have near wide open throttle during operation (most of the time). NOTE: A Honda engine with similar performance costs about 2X the Predator. I would go with the Honda in this case. If it were 3X or 4X, then I might stick with the cheaper engine. But the Honda is worth the extra $ in this case. VIDEO This video is part of a series describing an EV conversion of a Geo Metro.
    1 replies | 339 view(s)
  • buenijo's Avatar
    02-01-2025, 10:15 PM
    I fired the steam generator today. The burner was not working well at all. I shut down after a short period and ordered a second blower fan. Previously, when I had the blower on the burner head to force primary air, the burner worked well at LOW outputs. Increasing the output would cause soot to be produced. I could literally see some black soot blowing out of the exhaust port. I also verified soot accumulation on the steam generator tubing. With the blower moved to the underside to provide only secondary air (bypassing the burner head), what I witnessed was a white haze in the exhaust and strong smell of propane. What I believe is happening is the increased pressure in the combustion chamber due to the new blower position is preventing the burner venturi from providing sufficient primary air. So, propane gas is getting forced UP into the combustion chamber from the burner head with the vast majority not mixing with primary air. So, much of the propane gas is just moving through the unit, getting blown out the exhaust ports, and condensing in air to cause the white haze. Makes sense. So, I need to provide a blower for BOTH primary air (on the burner head as before) AND secondary air (on the underside bypassing the burner head). This seems reasonable. Good news is I don't have to do additional fabrication. I just need to keep the blower on the underside, then add a second blower to the burner head as before (I already have the attachment). (02-02-25) The fan arrived this evening. I'll fire it up when I get a chance - hopefully this weekend. I will also enlarge the exhaust port as removing the steam generator and re-installing is not difficult. (02-04-25) Nothing material to share. Just thoughts. So far, I can see a final prototype as not terribly difficult to assemble for small production runs. Yeah, of course this assumes I can get the damned thing to even work! So far so good. But the deck is stacked against me. I have no illusions. I'll just keep plugging away slowly and see what unfolds. That noted, I'm liking the basic design right now. (02/07/25) Not gonna fire the unit today as it's raining. I removed the steam generator yesterday and added an additional exhaust port. I also placed some ceramic fiber on the base of the combustion chamber, then reinforced the seal for the secondary blower (the one on the underside). Everything appears to be ready for the next test. (02/08/25) Gonna wait till next week for next test. No time this weekend.
    44 replies | 24417 view(s)
  • buenijo's Avatar
    01-29-2025, 02:10 PM
    A TALE OF TWO BOILERS The first video depicts a large monotube steam generator with all safety systems disabled and low (or NO) water flow. The burner was allowed to continue firing until the tube ruptured. The second video shows a firetube boiler that exploded due to operator error. The lesson here is the monotube steam generator is VASTLY safer than traditional boilers. Indeed, I argue a monotube steam generator with all pressure contained within small diameter tubing does NOT present a material explosion hazard. The tube can rupture, but only at a localized point. The pressurized contents of the tube must move through the long tube before escaping. So there is no explosion. Furthermore, the mass of saturated water in a monotube steam generator is VASTLY lower than a traditional firetube boiler of the same power rating. So the quantity of energy contained in a monotube steam generator is a small fraction of the energy contained in a firetube boiler of the same power rating. A firetube boiler heats a large mass of water contained within a large pressure vessel. During a catastrophic failure, the pressure vessel shell rips apart to expose the large mass of saturated water to atmospheric pressure. Much of the water flashes to steam almost instantly. BOOM! Personally, I would NEVER build a steam engine system that uses a large pressure vessel to heat water for steam generation. This is why I designed my engine to operate at a constant output. A large mass of saturated water is very useful for meeting transients in engine output. This is very difficult for a monotube steam generator. So I just sidestepped the problem. The alternative I will try is using the engine-driven alternator to maintain charge on a small battery system, then either operate the engine ON/OFF or HIGH/LOW to meet variable energy demands.
    44 replies | 24417 view(s)
  • buenijo's Avatar
    01-24-2025, 06:15 PM
    https://flic.kr/p/2qGXzc7 I made the necessary changes (see attached pic - for reference, the steam generator casing is 8" diameter). I removed the steam generator and cut a hole in the base next to where the burner head mounts. I then replaced the steam generator. I did not have to disconnect the feed water or steam fittings because the feed water line is a flex hose, and the steam line connects to the condenser coil inside the pot still. I then adhered a PVC fitting to the underside on which the blower fan will connect. I removed the steam generator lid for inspection, and sure enough there is a lot of soot on the tubing. This is a consequence of a rich propane mixture (i.e. insufficient air). During the next run, I intend to run it very lean and hot to burn off the soot. Then I will see how high the burn rate will go. I need 5 gallons of condensate vaporized each hour. ADDENDUM: The adhesive I used didn't work out. So, I just put a coupling nut on the bolt that secures the burner head to the base of the roll cage, then used a second bolt to secure the PVC fitting along with gasket material. It's not going anywhere now. NOTE: If you reference the pic, you can see the pot still in the background along with the needle valve and pressure gage I use to set system pressure. The water enters the steam generator coil at the base of the coil via the check valve seen in the pic. Steam leaves the coil at the top, and this section of the tube is surrounded with three layers of ceramic fiber sleeve. The steam line then connects to the top of a separate SS coil that is INSIDE the pot still and submerged in water. The steam line penetrates a hole in a stainless steel bowl placed on top of the pot still. This bowl shields the steam line fitting underneath to provide protection in case of a steam leak (I also wear safety goggles, a face shield, and high temperature gloves). All steam condenses as it passes through the condenser coil, then the condensate leaves through the needle valve. The position of the needle valve sets the pressure. The steam temperature is controlled by varying the speed of the feed pump (steam line has a temperature probe connected via a copper tee fitting clamped onto the steam line and insulated with ceramic fiber). This configuration is set up only for steam generator testing. When the steam expander is installed, then all steam will move through the steam cylinder. The pressure in that case will be set by a combination of the clearance volume in the steam cylinder head and the load on the crankshaft which will be an alternator connected to a heating element installed in the pot still.
    44 replies | 24417 view(s)
  • buenijo's Avatar
    01-20-2025, 05:29 PM
    I fired the steam generator again today. It held around 700F at around 800 psig for about an hour. Took about 20 minutes to get it dialed in. I took the temperature over 800F for a while. I also took pressure to 1200 psig for a while as well. No leaks in the steam and condensate systems. No leaks in combustion chamber plug. No leaks in the burner. The main problem is LOW burner output. I previously considered this is caused by the combustion chamber being too small. But I am now convinced it is caused by insufficient air. I am forcing all air through the burner head. But I realized these burners are designed to burn in open air where a rich flame can mix with plenty of excess air. I know what I have to do to fix this - and it's gonna be a pain. Basically, I need to reconfigure the blower to force air into the combustion chamber bypassing the burner head. Yeah, I have no doubt I can do this. But I need to remove the steam generator. Good news is it seems to work well (albeit at half the output that I would like). ADDENDUM: I figured out a clever way to fix the burner problem. Should be a bit easier. I might not even have to remove the steam generator. We'll see.
    44 replies | 24417 view(s)
  • buenijo's Avatar
    01-10-2025, 10:55 PM
    I tested the steam generator again on 01/10/25 after replacing the steam fitting and modifying the plug on top of the combustion chamber. It took nearly 10 minutes to start generating superheated steam. There was a lot of hysteresis (temperature was all over the place - but no higher than 800F). Once I got it dialed in, it held pressure from 600-650 psig with steam line temperature of 650-700F for approximately 30 minutes. Unfortunately, a rubber attachment on the propane burner (used to direct air from a blower fan into the burner head to overcome back pressure from the steam generator) melted a bit and I saw some flames escaping. So, that's a good reason to shut down. I may try sealing with silicone tape or rtv. Based on testing, it seems like the combustion chamber is too small to achieve my originally desired power (see next post, I concluded the problem is insufficient air to the burner). But that's not a problem because the main purpose of this test rig is to develop the expander. The plan is to load the engine with an alternator connected to a heating element in my pot still. I can adjust the resistance to set the cut in speed low, and this will allow me to operate the engine at reduced power while keeping the rated pressure. A later prototype would be designed for higher steam production and higher rpm. For example, I'm looking at about 1500 rpm for the final prototype. But I can operate at lower rpm during development (hopefully, I can fix the problem and operate at full power).
    44 replies | 24417 view(s)
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  1. I began studying politics in 2002 after returning from Afghanistan on active duty military service. I quickly discovered Ron Paul. I started studying economics in 2005. By late 2005 I was buying gold and silver bullion for long term savings. Few individuals today have a clear understanding of economics. What remains of the U.S. Republic is in constant danger of destruction as long as this condition persists. As the economic collapse continues, the ignorant public will blame what they incorrectly believed to be a "free market" and "capitalism". They will then likely abandon what liberty remains for greater central control.
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Alternative energy. Economics. Political philosophy. Exotic reptiles.
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