Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: c2sco
  • Order by date
  1. c2sco

    high pressure restraints

    Dynamic load factor does come from cyclic loading as the load is taken up and released. Surge loads can ONLY be estimated when you know the surge pressures, and that comes from transient flow modelling of the system. I can send you a paper on the subject if you like.
  2. c2sco

    high pressure restraints

    Yes, that's correct in some situations. However you need to be aware of the amplifying effect of harmonic motion in the pipe and to represent this there is a so-called "Dynamic load factor", which can be up to 2. If unknown, the safe assumption is to multiply the answer from BigInch's method by...
  3. c2sco

    high pressure restraints

    PS I should also have said that these programs only work out pressure-time history, they don't calculate forces on pipes, but I can help with that if needed. Stuart
  4. c2sco

    high pressure restraints

    vodeni, Someone has obviously considered water hammer (also known as surge or transient flow) there since you refer to a "surge relief system". As eadwine states, such conditions occur whenever there are flow rate changes. Normally these are slow enough not to give much problem with pipe...
  5. c2sco

    Flash points in NFPA Haz-01

    Thanks, I'd have expected that too, and am presently making that asumption. I've got the flash points data from several hits using a search engine, but they don't mention this and I don't have a copy of the original document (and am having difficulty persuading my client to buy one!) which in...
  6. c2sco

    Flash points in NFPA Haz-01

    Please can anyone tell me if the flash points quoted in this document (previously NFPA 325) relate to closed cup values or open cup ones? Thanks.
  7. c2sco

    Redundancy / discrete systems in modern DCS systems

    Matt, Many thanks, it looks interesting. At 365 pages it's going to take a while to digest! Wilton / Billingham is a crying shame (as is most of British manufacturing industry). When ICI built it, it was a great complex, as was Runcorn, and we were proud to be part of one of the world's...
  8. c2sco

    Redundancy / discrete systems in modern DCS systems

    No, I live in Chester. I lived in Normanby until I was 18, Dad now lives in New Marske. I worked for ICI for 20 years in mid Cheshire and Runcorn, spending some time on project work at Wilton in the 90s. Since leaving ICI in 1998 I have done a few months' work for Invista (sadly plant now...
  9. c2sco

    Redundancy / discrete systems in modern DCS systems

    Thanks, I've sent an e-mail to Siemens, see what transpires. Curiously, Prosalus turn out to be a company whose office is about 10 miles from my father's house in Teesside, so I'll contact them and maybe get some customised help if I can call in some time. I don't really need a course, maybe a...
  10. c2sco

    Redundancy / discrete systems in modern DCS systems

    Thanks for your replies. What you are saying all sounds in agreement with what I thought. I don't know anything about data highways - but I can imagine. I seem to remember being told about various protocols for LANs many years ago which involved packets of data being sent around - I guess the...
  11. c2sco

    Redundancy / discrete systems in modern DCS systems

    Russell, Thanks for your reply. I did look through the various forums and thought this was my best bet! Maybe not, but if you are happy to try, so am I. PFD=probability of failure on demand, ie (say) the level gets higher than the trip point. PFD= probability that the system of level...
  12. c2sco

    Redundancy / discrete systems in modern DCS systems

    I'm a chemical engineer in England, involved with safety integrity assessments for chemical plants. I'm struggling with understanding the meaning of multiplicity, or redundancy, inside modern DCS systems, which is often relevent to these assessments. We work to BS EN 61511 / BS EN 61508, where...
  13. c2sco

    Heat transfer through a hollow cone

    mprice, Sorry, I gave a false "OK" to your re-arrangement which explains your problem with substituting numbers since. The correct re-arrangement of my equation is dT = [Q.L.ln(Xh/L)]/kpZD If you look at my worked example you'll see that's what I used to get the sensible answer of 24.92 degC...
  14. c2sco

    Can citric acid really form a dust explosion hazard?

    It depends very strongly on the particle size and dryness. If your particles are small, say substantially below 100microns, and dry, then yes it will be explosive at much lower concentrations than 70%! 20-40 g/m2 is a decent guess, and this is quite dense, enought to obscure a light bulb at say...
  15. c2sco

    Heat transfer through a hollow cone

    mprice, yes, you re-arranged the formula correctly. As sailoday28 pointed out I've omitted the minus sign - pure laziness! You can ignore convection, but beware ignoring radiation unless your temperature is similar to the surrounding temperature. If I substitute into this equation, I get for...
  16. c2sco

    Heat transfer through a hollow cone

    I'd assumed there is no heat loss from his comment "I am only interested in heat flow inside the walls of the cone." Convection could be built into the calculus treatment but it would get awfully complicated. My current knowledge of Bessel functions is close to that before I went to university...
  17. c2sco

    Heat transfer through a hollow cone

    Difficult without a diagram, but here goes... Consider a cone, length L, base diameter D, thickness Z Assume no heat losses other than heat flowing out of the base. Assume Z is constant. Assume that the hot boundary is a conic circle at a distance Xh from the apex, temperature Th. You have to...
  18. c2sco

    Low temperature refrigeration

    Thanks a lot everyone. I'm convinced! But so is the customer - and so he's gone away to sulk in his lab and consider other ways of purifying his raw materials!! Never mind, he'll be back with a new proposal soon I guess. If he can't find one, LN2 must be the way to go at this scale. Maybe next...
  19. c2sco

    Evaporator design criteria

    Hm, thanks for those. MJC. Actually I am a "wise, gray-haired older engineer" - well maybe not all that wise, as I've not come across this exact configuration before! I'm only looking for real experience hints. RMW. I'll try the sources you suggested - I've not seen the sugar one before. I'm...
  20. c2sco

    Evaporator design criteria

    Hi, I'm designing a new evaporator as part of a plant modification in the UK. It will replace an existing evaporator that will be too small for the modified process. The evaporator removes water from organics. It has forced circulation, the external pump pushing a high flowrate of liquid...

Part and Inventory Search

Back
Top