Stillthe1 Posted April 13, 2016 Share Posted April 13, 2016 No waiting around for a Still Ladies & Gents! "Can be on your floor in a week! Start making the money, your already talented right?" - We will ship this anywhere in the USA Free! Price: $79,900.- NEW - 250 Lt. 3 Column Type Still: Please direct inquires to romesburg@gmail.com or just give us a ring. (810)794-8077 Cheer's, Scott D. Romesburg Romesburg International, LLC. 250 Lt. Type -3 Column Still NEW.pdf Link to comment Share on other sites More sharing options...
ebstauffer Posted April 13, 2016 Share Posted April 13, 2016 25 psi? I call bullshit. Link to comment Share on other sites More sharing options...
HedgeBird Posted April 14, 2016 Share Posted April 14, 2016 25 psi? I call bullshit. A 25 psi max on a steam jacket does not seem that crazy.. Most low pressure boilers/systems are running with 15 psi relief valves so designing/building/rating a steal appliance (the jacket on the still kettle) at 25 seems reasonable. Link to comment Share on other sites More sharing options...
PeteB Posted April 15, 2016 Share Posted April 15, 2016 I don't know exactly how steam jackets are constructed so please educate me if I am wrong. Is the jacket a second "skin" welded on the outside of the pot? If such a jacket held 25 PSI of steam then that would be pushing the pot inwards and probably cause it to collapse. A vacuum is about 15 PSI and that collapses stills. !!! Link to comment Share on other sites More sharing options...
HedgeBird Posted April 15, 2016 Share Posted April 15, 2016 I don't know exactly how steam jackets are constructed so please educate me if I am wrong. Is the jacket a second "skin" welded on the outside of the pot? If such a jacket held 25 PSI of steam then that would be pushing the pot inwards and probably cause it to collapse. A vacuum is about 15 PSI and that collapses stills. !!! Most commercial steam heated (jacketed) kitchen kettles are actually rated much higher than 25 psi and they do not collapse. Here is one example of a steam jacketed kettle that is designed to operate at 50 psi: http://www.webstaurantstore.com/cleveland-kdl-200-200-gallon-stationary-2-3-steam-jacketed-direct-steam-kettle/390KDL200.html I think if its rated above 15 psi then it might need to be ASME certified. One would think a 15 psi vacuum pulling from the inside would be the same as a 15 psi pressure pushing from the outside, but it seems that is not the case: http://sache.org/beacon/files/2007/02/en/read/2007-02-beacon-s.pdf Link to comment Share on other sites More sharing options...
meerkat Posted April 15, 2016 Share Posted April 15, 2016 One would think a 15 psi vacuum pulling from the inside would be the same as a 15 psi pressure pushing from the outside, but it seems that is not the case: http://sache.org/beacon/files/2007/02/en/read/2007-02-beacon-s.pdf For all practical purposes, 15 psi of vacuum in the tank is the same as 15 psi of pressure in the jacket. The inner shell only "sees" the difference in pressure between the inside and the outside. A clever variant of the external jacket is the dimple jacket. The outer shell is dimpled at about 6" centers and each dimple is welded to the inner shell. This dramatically reduces the unsupported area and allows the use of much thinner inner shells. Google will show you pictures. One of the less predictable failures I have seen with a jacketed vessel was one where only low pressure cooling water was put through the jacket. Unfortunately the inlet and outlet water valves were closed and when hot resin was dumped into the tank the trapped cooling water tried to boil with nowhere to go and totally destroyed the inner shell. For this reason even cooling jackets often have pressure relief valves. Link to comment Share on other sites More sharing options...
mendodistilling Posted April 15, 2016 Share Posted April 15, 2016 No way its the same. I have crushed tanks with vacuums. Not ever exploded a tank with low pressure. Link to comment Share on other sites More sharing options...
mendodistilling Posted April 15, 2016 Share Posted April 15, 2016 You have a convex strength when it's pressurized. Link to comment Share on other sites More sharing options...
mendodistilling Posted April 15, 2016 Share Posted April 15, 2016 I can put an atmosphere of vacuum on your tanks or stills and scrap them into junk in under 3 minutes of vacuum with my vacuum pump @ 100torr. Enough pressure to where if I used a keg instead of heavy metal it would just crush it like a soda can. I do a lot of vacuum distillation and my Haskell pump will eat your still for lunch. Link to comment Share on other sites More sharing options...
PeteB Posted April 16, 2016 Share Posted April 16, 2016 For all practical purposes, 15 psi of vacuum in the tank is the same as 15 psi of pressure in the jacket. The inner shell only "sees" the difference in pressure between the inside and the outside........ No way its the same. I have crushed tanks with vacuums. Not ever exploded a tank with low pressure. mendo and hedgebird, read the above by meerkat I think you both agree that if you pull a vacuum in the pot of a still it could easily collapse, (I have seen one) unless it was built for a vacuum. Or if you leave the inside of the pot open to atmosphere and have a jacket at 15 psi around the outside of the pot, the inward forces on the pot wall are the same as in the line above. (The welded jacket would probably strengthen the pot walls a bit) To run the jacket of a pot at 25 psi without crushing the pot would require much thicker pot walls than if it was just a few PSI. Thicker walls mean slower heat up. Link to comment Share on other sites More sharing options...
meerkat Posted April 16, 2016 Share Posted April 16, 2016 You have a convex strength when it's pressurized (internally). {italic added by meerkat} This is correct and is the reason why the failure is often not quickly detected. The pressure in the jacket does not distort the outer part of the jacket, while the inner wall of the jacket (i.e. the shell of the actual tank) can be bulging inwards or even ruptured but it is not visible from outside the tank. I remember one instance where we only discovered the problem when the distorted tank wall fouled and stalled the agitator. My previous post was referring to the pressure in the jacket destroying the shell of the tank from the outside. I agree with you that a cylindrical vessel can withstand a much greater internal pressure than external pressure. The larger the tank diameter the more susceptible it is to this type of damage from the outside, but I have seen relatively small bore (2") jacketed piping where the inner pipe was crushed almost flat by steam in the jacket. Link to comment Share on other sites More sharing options...
HedgeBird Posted April 16, 2016 Share Posted April 16, 2016 Really the only argument that I am making is that it is both possible and practical to design and build a steam jacketed kettle that operates at 25 psi; and that its not in anyway unbelievable or shocking to think that the still in question may well have been designed to operate with steam at that pressure. Link to comment Share on other sites More sharing options...
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