Results 1 to 4 of 4

Thread: Pneumatic Unloading Nozzles

  1. #1

    Pneumatic Unloading Nozzles

    I am evaluating an existing unloading system for a vessel which uses a top unloading nozzle whichin turn goes to a dust collector. There is a rotary lobe blower on the outlet of the dust collector. The present unloading nozzle consists of a 3" diameter pipe which is 18 ft long. The bottom 4 feet on this unloading nozzle have a 4" diameter pipe which is open on the top and bottom. We are conveying alumina pellets(size is 14 tyler mesh) . It presently takes up to 20 hours to empty the bin which contains 12 metric tons. The blower capacity is 1500 SCFM. The conveying piping is 6" NPS. I realize that my problem is probally caused by choked flow in the unloading nozzle and excessive pressure drop in this pipe and flex hose. Are there any standard designs for this type of unloading nozzles. This type of system is used in ship unloaders for larger capacities, but I have been unable to find vendors for this individual component. It may be simple enough to manufacture anywhere.

  2. #2
    Dennis Hauch - Freeport, TX, USA Guest

    Vacuum Wand


    The length and the bore of the existing vacuum nozzle are wholly incompatible with your 6” system, it should be replaced. Coperion-Waeschle, (281) 449-9944, offers exactly the nozzle you are looking for, I have used it with good success. Speak to Tony Kniffen.

    The blower flow is about right for your 6” system. With the pickup problem resolved, you can expect to be able to unload the 12 metric tons in one to two hours.

    One other thing, the flex hose length should be as short as it is possible to make it. I recommend a packed stainless steel hose that is specifically designed for pneumatic conveying applications. The bore of these hoses, while corrugated, is surprisingly smooth.

    Dennis Hauch

  3. Pneumatic Unloading Nozzles

    Dave - be careful, too agressive a transfer may turn your alumina pellets to dust. Need to evaluate their fragility.
    Never use a plastic hose for alumina - too abrasive.
    Spiral wound smooth bore SS hoses that are suitable, include Federal Hose Superflex, some Truflex hoses, Hose Master T-Rex Smoothbore.

  4. David,

    We have undertaken research work into the design of vacuum unloading nozzles for use with alumina. Please send me your postal address and I'll get some of our papers put in the post to you.


    Richard Farnish

    The Wolfson Centre for Bulk Solids Handling Technology
    University of Greenwich, London, UK

Similar Threads

  1. pneumatic cotton unloading system
    By vishal2419 in forum Pneumatic Conveying
    Replies: 9
    Last Post: 2nd October 2016, 11:50
  2. Pneumatic Lime Unloading from Truck
    By sebabu in forum Pneumatic Conveying
    Replies: 5
    Last Post: 6th February 2010, 22:41
  3. Pneumatic Unloading of Lime 0-8 mm
    By Piechbi in forum Pneumatic Conveying
    Replies: 5
    Last Post: 23rd January 2010, 16:02
  4. Pump for Pneumatic Unloading
    By Author in forum Pneumatic Conveying
    Replies: 3
    Last Post: 1st April 2006, 11:46
  5. Fly Ash Unloading by Using Pneumatic System
    By Rajendra Patel in forum Pneumatic Conveying
    Replies: 2
    Last Post: 27th October 2005, 19:36

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Single Sign On provided by vBSSO