EN 17877:2023

Dynamic mixers and agitators - Definitions and hydraulic characterizations

This document defines the terms and definitions relating to the field of dynamic mixing and agitation. It covers the hydraulic characteristics of mixers and agitators. It is intended to contribute to mutual understanding of the various stakeholders in a mixing or agitation project: manufacturers, users, integrators, inspection agencies, etc.
This document is applicable to mixing and agitation systems where there is at least one dominant liquid phase.
It does not apply to:
-   static mixers;
-   kneaders;
-   submersible mixers covered by ISO 21630;
-   aerators;
-   pumps.
Annex A lists the definitions in alphabetical order.

Dynamische Rührwerke und Agitatoren - Definition und hydraulische Charakteristik

Dieses Dokument definiert Begriffe, die sich auf das Gebiet des dynamischen Mischens und Rührens beziehen. Es behandelt die hydraulischen Eigenschaften von Rührwerken und Agitatoren. Es soll zum gegenseitigen Verständnis der verschiedenen Beteiligten an einem Misch- oder Rührprojekt beitragen: z. B. Hersteller, Anwender, Integratoren, Prüfstellen usw.
Dieses Dokument ist anwendbar auf Misch- und Rührsysteme mit mindestens einer dominanten Flüssigphase.
Es ist nicht anwendbar auf:
   statische Rührwerke;
   Kneter;
   Tauchrührwerke, die in ISO 21630 behandelt werden;
   Belüfter;
   Pumpen.
In Anhang A werden die Begriffe in alphabetischer Reihenfolge aufgeführt.

Mélangeurs et agitateurs dynamiques - Définitions et caractéristiques hydrauliques

Le présent document définit les termes et définitions relatifs au domaine du mélange et de l’agitation dynamiques. Il couvre les caractéristiques hydrauliques des mélangeurs et agitateurs. Il vise à contribuer à la compréhension mutuelle des différentes parties prenantes dans un projet de mélange ou d’agitation : fabricants, utilisateurs, intégrateurs, organismes de contrôle, etc.
Le présent document est applicable aux systèmes de mélange et d’agitation où il existe au moins une phase dominante liquide.
Il ne s’applique pas aux :
—   mélangeurs statiques ;
—   malaxeurs ;
—   mélangeurs immergés couverts par l’ISO 21630 ;
—   aérateurs ;
—   pompes.
L'Annexe A énumère les définitions par ordre alphabétique.

Dinamične mešalne naprave in mešala - Definicije in hidravlične karakteristike

Ta dokument določa izraze in definicije v zvezi z dinamičnim mešanjem in stresanjem. Obravnava hidravlične karakteristike mešalnih naprav in mešal. Njegov namen je prispevati k medsebojnemu razumevanju različnih deležnikov, ki so vključeni v projekt mešanja oziroma stresanja: proizvajalcev, uporabnikov, integratorjev, inšpekcijskih služb itd.
Ta dokument se uporablja za sisteme za mešanje in stresanje, pri katerih prevladuje vsaj ena tekoča faza.
Ne uporablja se za:
–   statične mešalnike;
–   gnetilnike;
–   potopne mešalnike, zajete v standardu ISO 21630;
–   prezračevalnike;
–   črpalke.
V dodatku A so navedene definicije v abecednem vrstnem redu.

General Information

• Status: Published
• Publication Date: 07-Nov-2023
• ICS: 01.040.23 - Fluid systems and components for general use (Vocabularies)
• ICS: 23.100.99 - Other fluid power system components
• Technical Committee: CEN/TC 458 - Stirring and mixing industrial equipment (provisional)
• Drafting Committee: CEN/TC 458/WG 1 - Terminology
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 08-Nov-2023
• Due Date: 28-Sep-2023
• Completion Date: 08-Nov-2023
• Ref Project: SIST EN 17877:2024 - Dynamic mixers and agitators - Definitions and hydraulic characterizations

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2024
Dinamične mešalne naprave in mešala - Definicije in hidravlične karakteristike
Dynamic mixers and agitators - Definitions and hydraulic characterizations
Dynamische Agitatoren - Definition und hydraulische Charakteristik
Mélangeurs et agitateurs dynamiques - Définitions et caractéristiques hydrauliques
Ta slovenski standard je istoveten z: EN 17877:2023
ICS:
01.040.23 Tekočinski sistemi in sestavni Fluid systems and
deli za splošno rabo (Slovarji) components for general use
(Vocabularies)
23.100.99 Drugi sestavni deli Other fluid power system
hidravličnih sistemov components
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17877
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2023
EUROPÄISCHE NORM
ICS 01.040.23; 23.100.99
English Version
Dynamic mixers and agitators - Definitions and hydraulic
characterizations
Mélangeurs et agitateurs dynamiques - Définitions et Dynamische Mischer und Rührwerke - Definition und
caractéristiques hydrauliques hydraulische Charakteristik
This European Standard was approved by CEN on 8 October 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17877:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
3.1 Basic mixing operations . 5
3.2 Mixing parts . 6
3.3 Mixer types . 17
3.4 Impeller types . 21
3.5 Hydraulic data . 28
3.6 Mechanical data . 37
4 Symbols and associated formulae . 40
Annex A (informative) Alphabetical index . 45
Bibliography . 49

European foreword
This document (EN 17877:2023) has been prepared by Technical Committee CEN/TC 458 “Industrial
rotating mixing systems”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2024, and conflicting national standards shall be
withdrawn at the latest by May 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
Introduction
Dynamic mixers and agitators are used mainly to set in motion one or more phases including at least one
liquid and maintain mixture conditions and/or to promote mass transfer and/or heat transfer.

1 Scope
This document defines the terms and definitions relating to the field of dynamic mixing and agitation. It
covers the hydraulic characteristics of mixers and agitators. It is intended to contribute to mutual
understanding of the various stakeholders in a mixing or agitation project: manufacturers, users,
integrators, inspection agencies, etc.
This document is applicable to mixing and agitation systems where there is at least one dominant liquid
phase.
It does not apply to:
— static mixers;
— kneaders;
— submersible mixers covered by ISO 21630;
— aerators;
— pumps.
Annex A lists the definitions in alphabetical order.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1 Basic mixing operations
3.1.1
agitation
motion of one liquid using a rotational device in a tank
3.1.2
mixing
motion of one substance or more through a liquid using a rotational device in a tank
3.1.3
homogenization
blending miscible liquids
mixing two or more miscible liquids to generate one liquid phase using a mixing unit
3.1.4
dissolving
solute a soluble solid into a liquid using a mixing unit
3.1.5
solid suspension
solid particles suspended in a liquid using a mixing unit
EXAMPLE Flocculation, process drinking yoghurt, food and chemical applications.
3.1.6
solid dispersion
small solid particles (powder) blended in a dominant liquid phase using a mixing unit
EXAMPLE Dye in ink or cocoa in chocolate milk.
3.1.7
emulsion
mixing of two or more immiscible liquids into each other using a mixing unit
Note 1 to entry: To prevent the liquids from separating out, a third liquid called a surfactant is added.
3.1.8
gas dispersion
shearing of larger gas bubbles to smaller ones using a mixing unit
Note to entry 1: Smaller bubbles have larger relative surface area and thereby enhancing mass transfer between the
gas and liquid phases.
3.1.9
heat transfer
circulation of fluids in tank to promote faster heating or cooling transmission to fluids using a mixing unit
3.1.10
fermentation
process where microorganisms are used to digest organic matter using a mixing unit which ameliorate
the contact between all the components
EXAMPLE Yoghurt, cheese culture and sour cream in dairy applications.
3.2 Mixing parts
3.2.1
mixing unit
mixing system
unit consisting of a mixer and a tank including all necessary accessories to provide the mixing of gas,
liquid, paste or powder into the liquid continuous phase
Note 1 to entry: See Figure 1.
Key
1 mixer
2 tank
3 baffle
Figure 1 — Principle of a mixing unit
3.2.2
mixer
agitator
equipment inducing liquid motion by mechanical rotation in a delimited tank
Note 1 to entry: See Figure 2.
Key
1 drive head
2 shaft
3 impeller
Figure 2 — Example of a mixer
3.2.3
drive head
unit consisting of all parts outside of the vessel including at least a drive unit (3.2.4)
Note 1 to entry: If no coupling (Figure 3, key 6) the drive shaft is used as the mixer shaft.
Note 2 to entry: See Figure 3.
a) 2D view b) 3D view
Key
1 drive unit
2 lantern
3 drive shaft
4 mixer seal
5 base flange (or mounting flange)
6 coupling between the drive shaft and the mixer shaft
Figure 3 — Example of a drive head
3.2.4
drive unit
component(s) which rotate(s) mixer shaft
3.2.5
lantern
housing(s) between drive unit and base flange which contain(s) mixer seal and/or a guiding system
and/or shaft connecting parts
3.2.6
drive shaft
part of shaft located in drive head and designed to transfer the torque from drive unit to mixer shaft
3.2.7
mixer seal
seal device that separates inside tank from outside tank and/or prevents substance entering and/or
leaving the tank
Note 1 to entry: A shaft seal can be e.g. a lip seal, a labyrinth seal, a mechanical seal, a stuffing box, an hermetic
seal (e.g. magnetic coupling).
Note 2 to entry: See Figures 4 to 6.

Key
1 mixer shaft
2 seal
3 base flange
4 seal, base flange
Figure 4 — Lip seal
Key
1 mixer shaft
2 seal, rotating part
3 seal, stationary part
4 spring
5 base flange
6 seal, base flange
Figure 5 — Single mechanical seal
Key
1 mixer shaft
2 seal
3 base flange
Figure 6 — Labyrinth seal
3.2.8
base flange
mounting flange
mixer flange
connecting plate between the mixer and the tank which holds the drive head
Note 1 to entry: See Figure 7.
3.2.9
shaft restraint system
device that allows an easily maintaining of mixer seal and which is preventing mixer shaft from sliding
down when drive head and/or axial lock is released
Note 1 to entry: See Figure 7.
Key
1 drive shaft
2 base flange
3 shaft restraint system
4 mixer shaft
Figure 7 — shaft restraint system
3.2.10
mixer shaft
part of the shaft located in the tank and designed to support the impeller(s)
Note 1 to entry: With only one single shaft, the mixer shaft is used as drive shaft (see Figure 3, key 3).
Note 2 to entry: Mixer shaft can consist of several shaft steps. Some shaft steps may have no impeller installed on.
Note 3 to entry: See Figure 8.
a) 2D view b) 3D view
Key
1 impeller
2 mixer shaft
Figure 8 — Example of a mixer shaft with impellers
3.2.11
impeller
mixer element that moves the mixed media
Note 1 to entry: There are different types of impellers such as propellers, anchors, ribbons, turbines. Most
frequently, impellers are fitted with blades (from 2 to 6).
3.2.12
in tank bearing
in tank device that guides the mixer shaft, can be bushing or bearing
Note 1 to entry: When an in tank bearing is located at least above the lowest impeller, it is called an intermediate
bearing (see Figure 9).
Note 2 to entry: When an in tank bearing is located at the bottom of the tank, it is called a bottom bearing (see
Figures 10, 11 and 12).
Note 3 to entry: All mixers designed with in tank bearings cannot be run without them.
Key
1 mixer shaft
2 wearing sleeve
3 bushing
4 support structure
Figure 9 — Example of intermediate bearing
Key
1 mixer shaft
2 wearing sleeve
3 support structure
4 support structure
5 bushing
Figure 10 — Example 1 of a bottom bearing schematic drawing

Key
1 screw
2 O-rings
3 bushing
4 support structure
5 mixer shaft
Figure 11 — Example 2 of a bottom bearing schematic drawing

a) 2D view b) 3D view
Figure 12 — Example of bottom bearing
3.2.13
deflection limiter ring
guide ring
safety device, immersed in the liquid, located at the end or along of mixer shaft and intended to limit the
shaft deflection without any contact with the mixer shaft under normal operating conditions and avoid
overstress
Note 1 to entry: See Figure 13.

Key
1 mixer shaft
2 support structure
3 deflection limiter ring
Figure 13 — Example of intermediate deflection limiter ring
3.2.14
baffle
static element fixed to the tank wall and sometimes to tank bottom
Note 1 to entry: A baffle is used to change the flow direction in a tank and/or to prevent the liquid from swirling
and vortexing also called batch rotation.
Note 2 to entry: See Figure 1, key 3.
3.2.15
fillet
static construction at the tank wall/or bottom used to direct the flow and/or prevent settling
Note 1 to entry: See Figure 14.
Note 2 to entry: A plough is also a type of fillet. See Figure 15.

Key
1 fillet
Figure 14 — Example of a fillet

Key
1 plough
Figure 15 — Example of a plough
3.3 Mixer types
3.3.1
bottom entry mixer
bottom mounted mixer
mixer located at tank bottom with axis which can be slightly tilted towards the walls
Note 1 to entry: See Figure 16.
a) 2D view b) 3D view
Figure 16 — Example of a bottom entry mixer
3.3.2
side entry mixer
side mounted mixer
mixer fixed on tank wall which could be angled
Note 1 to entry: See Figure 17.
Note 2 to entry: During mixer use, the mixer shaft axis can be orientable.

Key
1 propeller
2 tank
3 mixer shaft
4 support structure
Figure 17 — Example of a side entry mixer
3.3.3
top entry mixer
top mounted mixer
mixer fixed on the top of the tank or support over the tank/basin with a vertical axis or slightly inclined
to the vertical line
Note 1 to entry: See Figure 18.
Note 2 to entry: The axis of the mixer can be guided by means of an intermediate bearing or a bottom bearing.

Key
1 mixer
2 tank
3 mixer shaft
4 propeller
Figure 18 — Example of a top entry mixer
3.3.4
co-axial mixer
combined mixer with two mixer shafts on the same axis where the two impellers have two different
rotation speeds
Note 1 to entry: If the mixer shafts are rotating in the same direction a co-axial mixer is called a co-rotating mixer
otherwise it is called a contra-rotating mixer.
Note 2 to entry: See Figure 19.

a) 2D view b) 3D view
Figure 19 — Example of a co-axial mixer
3.3.5
rotor-stator
stator-rotor
mixing device consisting of a static element (stator) and an impeller(rotor)
Note 1 to entry: The rotor-stator is used to provide a high shearing in order to create an emulsion or a dispersion
of immiscible liquids.
Note 2 to entry: See Figure 20.
a) 2D view b) 3D view
Key
1 rotor
2 stator
Figure 20 — Example of a rotor-stator
3.4 Impeller types
3.4.1
anchor
impeller with two or more arms matching walls shape, located near to walls and providing a tangential
flow
Note 1 to entry: See Figure 21.
Note 2 to entry: Some anchors are fitted with a scraper device, intended to scrape the tank wall.
Figure 21 — Examples of an anchor
3.4.2 Propeller types
3.4.2.1
propeller
impeller generating an axial flow composed of tilted blades with an angle less than 45° with the horizontal
and which profile shape is curved, twisted or folded
Note 1 to entry: The shape and characteristics of the propeller are determined according to the desired
application.
3.4.2.2
high efficiency propeller
hydrofoil propeller
impeller with blades specially designed to reduce significantly the absorbed power and keeping the same
flow rate of a marine propeller
Note 1 to entry: See Figure 22.

Figure 22 — Example of a hydrofoil impeller
3.4.2.3
marine propeller
impeller composed of blades which are a portion of a helical screw, providing axial flow
Note 1 to entry: For traditional marine propeller the pitch is always one.
Note 2 to entry: See Figure 23.

Figure 23 — Example of marine propeller
3.4.2.4
double flow propeller
countercurrent propeller
propeller for which each tip is inversely tilted (twisted) to its central part
Note 1 to entry: For double-flow propeller, D > 0,9 T. See symbols definitions in Clause 4, Table 1.
Note 2 to entry: See Figures 24 and 25.

Figure 24 — Example 1 of a double flow propeller
Figure 25 — Example 2 of a double flow propeller
3.4.2.5
no-clog propeller
propeller designed to reduce clogging on blades
Note 1 to entry: See Figure 26.

Figure 26 — No-clog propeller
3.4.3
helical ribbon
impeller with one or more helical portions which rotate close to the tank wall
Note 1 to entry: The ribbon could be combined with an Archimedes screw located in the centre of the tank and
generating a flow reverse of the ribbon flow.
Note 2 to entry: See Figures 27 and 28.
Figure 27 — Example of a helical ribbon

Figure 28 — Example of an Archimedes screw
3.4.4
pitched blade turbine
impeller with flat and inclined blades often at 45° angle, generating an inlet axial flow and both axial and
radial outlet flows
Note 1 to entry: See Figure 29.
Figure 29 — Example of a pitched blade turbine
3.4.5
radial turbine
impeller with blades that generate a centrifugal outlet radial flow
3.4.5.1
radial disk turbine
radial turbine with vertical blades fixed on a disk
Note 1 to entry: It is possible to have different number of blades and/or different shapes of blade.
3.4.5.2
Rushton turbine
radial disk turbine with 6 vertical flat blades
Note 1 to entry: Proportional dimensions of a Ruston turbine can be found in literature. See [4].
Note 2 to entry: See Figure 30.

Figure 30 — Example of a Rushton turbine
3.4.5.3
saw tooth turbine
high shear turbine
impeller with a disk shape that has teeth on its outer edge
Note 1 to entry: See Figure 31.

Figure 31 — Example of a saw tooth turbine
3.4.5.4
retreat curve impeller
radial turbine with vertical curved blades
Note 1 to entry: See Figure 32.

Figure 32 — Exa
...