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  1. SREisme

    Thermal shocks in vertical falling thin film evaporators

    My guess is that the batch operation of the evaporator is more to blame for thermal cycling cracks (fatigue?) than the actual operating conditions. Assuming you run this equipment 4 hrs per day and shut it down for 20 hours per day, you are cycling the evaporator from approximately room...
  2. SREisme

    Triplex pump in series with a ... ?

    If you are just pumping from one tank to another in close vicinity, why not install a pump that can do 50gpm with a separate pipe run? Why do you need thousands of feet of pipe to go next door? What is the pressure at the outlet of your existing pipe with the 4000psi pump pressure? This...
  3. SREisme

    At what temperature is a wasteheat steam generator identical to a fired tube boiler?

    Thanks for the comments. My end goal is to determine the point at which a low water cutout must be installed on a waste heat boiler to prevent a steam explosion caused by reintroducing water to a dry boiler. We currently operate a number of waste heat steam generators with no low level safety...
  4. SREisme

    Forcemain sewer pipe mystery?

    If you are blowing water out of the top of your high point at ~100gpm, then you have a pressure drop in the line from your high point to your discharge equal to 100gpm of frictional losses plus the extra head in your standpipe. You say you have inspected the line in the past and not found...
  5. SREisme

    At what temperature is a wasteheat steam generator identical to a fired tube boiler?

    I sure can, Macmet. The boiler in question is a sulfur condenser in an oil refinery. It is a horizontal shell and tube steam generator with hot sulfur/ SO2/H2S vapors flowing through the tubes at 600-750F and ~10psig with boiler feedwater on the shell side making 70# saturated steam. This...
  6. SREisme

    At what temperature is a wasteheat steam generator identical to a fired tube boiler?

    A damaged boiler, ie twisted tubes, bent stays, minor leaks, etc are a problem but not my primary concern relating to the original post. My primary concern is the perceived risk of a boiler explosion resulting in flying debris and release of the hot process gases to atmosphere. I want to...
  7. SREisme

    At what temperature is a wasteheat steam generator identical to a fired tube boiler?

    Macmet- thanks for the reply. My application is in recovering heat from hot process gases or hot oils. We are well aware of the potential for a steam explosion due to injecting water into a hot oil pool due to a major tube leak. What we don't know is the potential for steam explosions caused...
  8. SREisme

    At what temperature is a wasteheat steam generator identical to a fired tube boiler?

    I am trying to understand the differences between unfired waste heat steam generators and fired boilers as it applies to a low water cutout requirement. NFPA requires a low water trip on all fired boilers, presumably due to the number of boilers that have exploded when water was lost. I can not...
  9. SREisme

    At what temperature should an unfired waste heat steam generator have a low water cutout?

    I am trying to understand the differences between unfired waste heat steam generators and fired boilers as it applies to a low water cutout requirement. NFPA requires a low water trip on all fired boilers, presumably due to the number of boilers that have exploded when water was lost. I can not...
  10. SREisme

    Set point of the minimum flow by-pass valve

    Preferably you would have a company standard of your own for minimum flow based on suction specific speed, specific speed, and BEP. Barring that I would ask the vendor what the minimum flow for long term reliable operation is, not short term failure, and set the flow rate at that. 40% of BEP...
  11. SREisme

    Sodium transport mechanisms in process streams

    We backflowed caustic (sodium hydroxide) into an amine system due to a loss of amine pressure. The sodium levels in the amine went through the roof. What I don't know is whether or not the sodium will leave the amine when the acid gas is stripped out in the regenerator tower. Conventional...
  12. SREisme

    Sodium transport mechanisms in process streams

    Can anyone tell me if there is a mechanism for sodium to migrate from a heat stable salt in an MEA solution to a liquid particle in an acid gas stream leaving an amine regenerator tower? More specifically, I am wondering if there is a connection between a caustic (sodium hydroxide)incursion...
  13. SREisme

    Silica and Alumina leaching from furnace refractory?

    Unclesyd- your reply makes me think you have seen this issue numerous times. Can you tell me what types of refractory you've seen it in, what services, what compositions, etc? Is this a start up issue due to whatever machanism is at work or can it continue to occur over the life of the...
  14. SREisme

    Silica and Alumina leaching from furnace refractory?

    Thanks, Unclesyd. Our refractory is installed in blocks, no guniting. We'll defintely be talking with our supplier. You call it dusting. I called it leaching as the deposit analysis was heavily weighted to Si, while the hotface brick is primarily Alumina. Do you see similar compositions? Is...
  15. SREisme

    Strange Fittings on Siemens Turbine Control Oil

    Try contacting Mr Jeff Painter at ABB in Richmond, VA. He is a field service engineer in their turbine division. They have some similarly funky fittings for control oil, although I don't remember them being exactly like yours.
  16. SREisme

    Fired Tube fouling and Refractory mineral relationships

    Has anyone experienced silica, alumina, or sodium leaching or volitizing out of newly installed hot face refractory in a fired furnace? We fouled a downstream waste heat boiler with a very fine, low density, thin ~1/32" coating that analyzes as Fe, Si, Al, Mn, Na, and other trace minerals. We...
  17. SREisme

    Silica and Alumina leaching from furnace refractory?

    Has anyone experienced silica, alumina, or sodium leaching or volitizing out of newly installed hot face refractory in a fired furnace? We fouled a downstream waste heat boiler with a very fine, low density, thin ~1/32" coating that analyzes as Fe, Si, Al, Mn, Na, and other trace minerals. We...
  18. SREisme

    water cooling jacket

    Controls SouthEast Inc (CSI) out of North Carolina makes bolt on valve jackets, jacketed pipe, and "contro trace" systems. Contro trace may be what you are looking for. It is often used in place of fully jacketed piping for high freeze point fluids. It's sort of a heavy duty steam tracing that...
  19. SREisme

    Recommend Mechanical Engineering Design Books

    Something else to consider in machine design is the ways the machinery will fail once put in service. They didn't teach it in school, but I recommend reviewing some of Heinz Bloch's books on machinery failure modes and troubleshooting for application on the user end. "Machinery Failure...
  20. SREisme

    Heat Transfer in Soil

    I agree that most of the heat from a fire will go to the atmosphere, especially a fast brush fire or tree top burn. However, I have seen the aftermath of forest fires where the ground is scorched to bare soil where the needle mat has been entirely consumed. I have heard other reports of major...

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