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Recent content by ccaissie

  1. ccaissie

    Increasing chain drive efficiency

    I am building a chain drive version of a geared "two man hand powered rice huller" for the Maine Rice Growing Project. I'm copying a Japanese made impact type huller that works well. Initially the idea of using sprockets and chain seemed feasible to increase the speed from a manual input of...
  2. ccaissie

    Reboiler calcs

    Sshep: Thanks for reply. Yes, reflux RATIO is 1.5 It does make sense that the operating lines would NOT be straight, as composition changes. Yeah, HVap of MeOH is very different than water. Vendor (Mr. K.Patel) is comfortable with 24" HETP, and so am I. Flood calcs work out well, now at...
  3. ccaissie

    Reboiler calcs

    Thanks, SShep: I am studying Kister's "Distillation Design", and have worked through the column design via McCabe-Thiele graphical methods. Packing suppliers have confirmed the basic design. Kister does not describe "internal" reflux as such. I assume we are talking of the descending liquid...
  4. ccaissie

    Reboiler calcs

    Thanks all, for previous help in this methanol distillation design, discussed under methanol volatilities: What would you recommend for simple calculations to design a reboiler. I know there are canned programs out there. This design is simple. All we need is more heat until it works, but...
  5. ccaissie

    Variable Methanol volatilities

    Much appreciated comments. As I am looking at 97% purity at the top, and moderate volumes in the process, the responses regrading pervaporation are maybe not relevant. The links to the biodiesel sites is an intuitive leap. Yes, it's biodiesel, but this process is for the waste methanol and...
  6. ccaissie

    Variable Methanol volatilities

    Thank you, 25362 and Katmar. I have Perry's 3rd and had not found the constant tables. I had not delved into the principles deeply, and as 25362 noted, this is the province of the pros. I also noted that the attachments weren't there. I reattach. They are the canned software graphs. Back...
  7. ccaissie

    Variable Methanol volatilities

    I had read in a post by member 25367 that the relative volatilities of Methanol/water change with purity. In designing a methanol column for a client, a packing vendor had stated some very high stage heights, saying methanol is different. By my own calcs, VLE's etc., I have come up with a...
  8. ccaissie

    Ceramic Hybrid Bearing Failure Analysis

    Thanks, Caoimhin1. The mixer was shipped so that there was no vibration and rotation which could have "indexed" a pattern. The number of indents and ball count are showing a realtionship. Flush-through is our standard design, but this case makes us want to think again about that. CSC
  9. ccaissie

    Ceramic Hybrid Bearing Failure Analysis

    dinjin: My first impression also was that the customer ruined our mixer by flushing it with dirt. But we need to be more analytical than that. CSC
  10. ccaissie

    Ceramic Hybrid Bearing Failure Analysis

    thgirw: I addressed the post to dinjin by mistake. See above.
  11. ccaissie

    Ceramic Hybrid Bearing Failure Analysis

    Dinjin: We saw no signs of unusual contact or pressure or wear on the shaft. The 440C (or european equivalent)bearing steel seems to behave well against the 316SS shaft. We're running tests now and all seems well, though a new sound, a squeak, has appeared, so we're getting a vib analysis...
  12. ccaissie

    machinig and then heat treating sheet steel

    I'm not too familiar with your designations in the UK, but the threads in the materials forums seem to be a good place to try. A relevant thread below: http://www.eng-tips.com/viewthread.cfm?qid=85260 Cheers, Colin
  13. ccaissie

    Ceramic Hybrid Bearing Failure Analysis

    The bearings are a ground matched set, Back to Back with the preload accomplished by compression of the 11 micron gap in the assembly. We have pretty much eliminated concerns whether this preload arrangement is correct. Something evidently over-rode the preload force. We're thinking it...
  14. ccaissie

    Ceramic Hybrid Bearing Failure Analysis

    We have had a failure of a ceramic hybrid angular contact bearing, and are seeking the root cause of this. We are using a lower pair of 6220 deep groove radial bearings which are intact, and an upper pair of 7218 bearings with a preload gap of 11 microns, which was properly torqued and locked...
  15. ccaissie

    Maximum hardness of 1026 steel

    Without extensive and expensive fabrication of the shape, 1026 is the best we can readily obtain. We did find that a major heat treatment company says that case hardening can get the surface region to RC40, and the core to about 30. This will be adequate. Thanks for your post! CSC

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