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Recent content by JEFF1

  1. JEFF1

    Unsteady Flow in Chilled Water Piping

    Has anyone witnessed unstable (unsteady) flow in a chilled water system, where GPM surges are observed?  I know of two situations where flowmeters indicate a cyclic change in flow of large magnitude in a period of seconds.  For one of the two locations, the cyclic nature of...
  2. JEFF1

    Flow measurement - water and water/glycol

    The only non-intrusive flow measurement technology that I know of that might have a chance of measuring flow in a hose "in situ" is magnetic flow measurement.
  3. JEFF1

    Chilled water evaporative cooling?

    I do not have practical experience with this, but I think that I remember that what you are describing can be done. This is a variation of an adiabatic saturation process. If I remember right, an adiabatic saturation process moves along a line of constant wet bulb temperature along the...
  4. JEFF1

    Pressurized Water Reactors

    I know that for highest thermal efficiencies, nuclear reactors will run at high temperatures. But I thought that there might be subsystems that operate at lower temperatures and pressures.<br> <br> The district heating system where I work handles thermal expansion and contraction with an...
  5. JEFF1

    Anyone Interested in a District Energy Forum?

    I work at a facility with a good sized district heating and cooling system, but it is not of the variety that avoids outside sources of energy. It does have a 2.2 million gallon chilled water storage tank to avoid electrical demand charge. I'd be interested in tuning in to such a forum, but...
  6. JEFF1

    Moisture on Final Filters in Blow-through AHU's

    The first explanation (bypass air condensing on cold filter media) sounds like a more probable explanation to me, especially if the construction is poor and there is a lot of bypass air. Condensate could even be forming in the cold air downstream of the coil before it reaches the filters. I've...
  7. JEFF1

    Magnetic Refrigeration

    Mechanical Engineering magazine had an interesting article in December '94 r.e. the future of magnetic refrigeration. I'm interested in knowing whether this is moving anywhere with respect to conventional HVAC equipment. There was some speculation at the time that it might be applicable to...
  8. JEFF1

    Chilled Water Systems for Building HVAC - Achieving High Temp. Rise

    Our facility is pretty well completed, and our primary interest is in making what we have work. I'd still be interested. I'm assuming that they would have to be mailed, as opposed to e-mailed. If you let me know, I'll send a mailing address if required.<br> <br> My experience has been that...
  9. JEFF1

    Chilled Water Systems for Building HVAC - Achieving High Temp. Rise

    R.e. dehumdification, yes, when the supply water temperature gets high enough, you can lose control of humidity in the buildings served by the system. Some buildings and some rooms require more dehumidification than others. So chilled water flow cannot be limited as much in these areas...
  10. JEFF1

    Chilled Water Systems for Building HVAC - Achieving High Temp. Rise

    The fins on typical air handler chilled water coils are either circular (older style, infrequently sold today)or "plate-fin", meaning that many tubes pass through large fins that are in the shape of a plate. The"plate-fins" are sometimes enhanced in geometry so that the create turbulence and...
  11. JEFF1

    Chilled Water Systems for Building HVAC - Achieving High Temp. Rise

    The only heat exchangers in this system are the heat exchangers in the chillers themselves and the heat exchangers in the air handling equipment. The air handling equipment is, essentially, air conditioners that used chilled water to cool the air. When you're speaking of heat exchangers, I...
  12. JEFF1

    Pressurized Water Reactors

    I do not work in the nuclear industry. However, I work with a district heating system that uses pressurized hot water. I would like to know if there is a similar experience base in the two industries. Specifically, in a typical district heating system, one might be dealing with 380 F...
  13. JEFF1

    Looking for fastener slide computer

    Try Holo-Krome Co., W. Hartford Connecticut 06110, 203-523-5235, division of Western Pacific Industries. They also had an address in Anaheim, CA, 4890 E. LaPalma Ave., 92807. I hope they're still around, I obtained this over ten years ago. This one was for socket head cap screws, flat head...
  14. JEFF1

    Leaking head gaskets in a large heat exchanger with high delta-T's

    We are working with a consultant, and the calculations thus far show no design problems. The head is to be shipped out for measurement of trueness of the face shortly. However, three identical exchangers have all leaked in the same quadrant of the head (where the hot fluid enters), so trueness...
  15. JEFF1

    Leaking head gaskets in a large heat exchanger with high delta-T's

    The studs are 193B7. We do three star pattern torque sequences, followed by a sequential pass, and then a second sequential pass going the opposite direction. The bolts are 3/4"-NC 10, and final torque is 220 lb-ft. We do not retorque, because we were concerned that the studs could be yielding...

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