1 / 31

CWP Customer Training Seminar

CWP Customer Training Seminar. Chapter: 19 Screw Elements: Types, Function, Identification. Basics on screw elements Conveying elements Kneading elements Neutral elements Installation of the screw elements Numbering of the screw elements Principle of operation of the screw elements.

jodie
Download Presentation

CWP Customer Training Seminar

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CWP Customer Training Seminar Chapter: 19 Screw Elements: Types, Function, Identification Basics on screw elements Conveying elements Kneading elements Neutral elements Installation of the screw elements Numbering of the screw elements Principle of operation of the screw elements Last Update: 01.2003/by:MK19.1

  2. CWP Customer Training Seminar • The Erdmenger patent "conditions of the sealing profile must be met" • Along the screw connection there must be the same cross-section at all points • Both shafts must have the same screw profile. Last Update: 01.2003/by:MK19.2

  3. Da Do Di Di a a Characteristic Dimensions Diameter ratio:Da / Di(indicates available volume) Specific capacity:Md / a3 (Indicates torque) Do = Outer screw diameter Di = Inner screw diameter a= Axle distance Last Update: 01.2003/by:MK19.3

  4. Conveying Elements Pitch (mm) a a Da p x Da High pitch Low pitch Last Update: 01.2003/by:MK19.4

  5. Conveying Elements Right and Left-Hand Pitch Extruder Rightflighted Elements Leftflighted Elements Conveying direction Conveying direction in against the direction of the extruder flow direction of the extruder flow Last Update: 01.2003/by:MK19.5

  6. Conveying Elements, Conveying, Last Update: 01.2003/by:MK19.6

  7. Kneading Blocks Kneading disc Stagger angle 1 1 2 2 3 3 4 4 5 (5) Wide kneading discs Narrow kneading discs Spacer ring Last Update: 01.2003/by:MK19.7

  8. Kneading Blocks • Kneading blocks comprise several kneading discs arranged behind one another. • The staggering angle by standard is 45 or 90° • The number and the width of the individual kneading discs is variable. • The position of the kneading discs at the beginning and the end should be identical, for compatibility with other kneading blocks (i.e. to keep the modular concept). Last Update: 01.2003/by:MK19.8

  9. Kneading Elements Last Update: 01.2003/by:MK19.9

  10. Kneading Elements Extruder Rightflighted Elements Neutral elements Leftflighted Elements Conveying direction Conveying direction Element without in the direction against direction own conveying of extruder flow of extruder flow Last Update: 01.2003/by:MK19.10

  11. Conveying and Kneading Elements, Left-Hand Pitch Last Update: 01.2003/by:MK19.11

  12. Quiz Q: Which connection between the screw element and the screw shaft is shown? A: Refer 18.1 ff Last Update: 01.2003/by:MK19.12

  13. Installation of Screw Elements Last Update: 01.2003/by:MK19.13

  14. Installation of Screw Set Elements Last Update: 01.2003/by:MK19.14

  15. Installation of Screw Set Elements 1-flight elements 2- flight elements 3- flight elements Faces always parallelly Faces always offset by 90° Faces always parallelly Last Update: 01.2003/by:MK19.15

  16. Profile Transitions Profile A Profile B Profile A Profile B • Transition piece required • for profile joint (profile A to B • if the faces of identical profiles are offset (kneading block) Risk of breakage Last Update: 01.2003/by:MK19.16

  17. Transition Elements • For technical fluidic reasons, but also to prevent mutual contact of the screws, a transition piece is necessary between different profile cross-sections, similar to that required for kneading blocks. • Spacer rings, with the same outside diameter as the inside diameter of the screw elements, can be used instead of transition elements in some cases. Last Update: 01.2003/by:MK19.17

  18. - - 0 0 . 2 1 0 6 0 / 0 6 0 - 2 4 8 0 4 0 Part Numbers on the Screw Elements Screw diameter Element length Material Pitch of conveying elements 00 Nitriding steel 05 Cr steel 68 CPR-HSS steel Profile No. of flights, direction 15 Wear and/or corrosion protected elements of composite materials 1 25 1 1-channel, right Screw element with sealing profile 2 2 2-channel, right Screw element with sealing profile 3 3-channel, right 6 Kneading block 4 1-channel, left 37 CPR - composite material 5 2-channel, left Connection Screw Elemnet/Shaft 3-channel, left 6 9 Special version Offset angle 00, 01, 02 Feather key (0°) 6-key 66, 67, 68 3 30° Kn.block : 4 0 5 24, 25, 34 Involute SC 4 45° 34 MEGA-Compounder 6 60° Other numbers available for special geometries. 9 90° No. of discs Last Update: 01.2003/by:MK19.18

  19. Recognising Screw Element Materials Material no. Material Specif. 00 05 Nitriding steel nitrified Standard wear protection HIP - composite 15 Corrosion and wear-resistant HIP - composite 25 Last Update: 01.2003/by:MK19.19

  20. Recognising Screw Element Materials Material no. Material Specif. Former standard wear protection HIP - composite 10 Soft martensitic hardened Cr-Ni steel with applied crest welding 28 Last Update: 01.2003/by:MK19.20

  21. Pressure Barrier Process Section Left-handed Conveying elements elements Conveying Kneading- Mixing elements elements Principle of Operation of the Screw Elements Mixing Kneading (homogenising) (dispersing) Last Update: 01.2003/by:MK19.21

  22. 2-flight elements Main portion of the product flows from one screw to the other. => lower transport capacity 1-flight elements Reduced product flow from one screw to the other. => improved transport capacity Conveying Mechanism Last Update: 01.2003/by:MK19.22

  23. Principle of Operation of the Conveying Elements Type of element Free cross-section Conveying efficiency 1-channel elements Standard elements "Undercut" elements Last Update: 01.2003/by:MK19.23

  24. Filling Level of Conveying Elements With decreasing pitch the free volume in the screw channel decreases, i.e. the filling level increases. Last Update: 01.2003/by:MK19.24

  25. Filling Level of Conveying Elements • Normally conveying elements with a high pitch are installed below the feed inlet. • The bulk material is compressed by the reduction in pitch in a downstream direction, i.e. as a result of reduction of the channel volume. Last Update: 01.2003/by:MK19.25

  26. X° standard X° neutral Merit comparison for different Kneading Blocks wide vs. narrow: standard vs. neutral: Type of element Mixing effect Conveying effect Type of element Mixing effect Conveying effect Kneading effect (shearing) Kneading effect (shearing) Last Update: 01.2003/by:MK19.26

  27. p [bar] p [bar] Left-Handed Elements product flow Last Update: 01.2003/by:MK19.27

  28. Left-Handed Elements Last Update: 01.2003/by:MK19.28

  29. Neutral kneader block Left-handed kneader block Left-handed screw element Principle of Operation of the Left-Handed Elements Build-up effect Type of element Right-handed screw element with low pitch Last Update: 01.2003/by:MK19.29

  30. re li re li re li re li re li 1 1 Tracer 2 2 0 50 100 150 Time (sec) 3 3 Residence Time with left and righthand KB with righthand kneading block without kneading block Last Update: 01.2003/by:MK19.30

  31. Recognising Screw Element Materials Q: Which features can be used to recognise the material of a screw element if the material code on the faces of the screw elements has become illegible with cleaning? A: refer Chapter 19, slide 18ff Last Update: 01.2003/by:MK19.31

More Related