Editing Mixing (process engineering) (section)

==Industrial mixing equipment==
At an industrial scale, efficient mixing can be difficult to achieve. A great deal of engineering effort goes into designing and improving mixing processes. Mixing at industrial scale is done in batches (dynamic mixing), inline or with help of [[static mixer]]s. Moving mixers are powered with [[electric motor]]s that operate at standard speeds of 1800 or 1500 RPM, which is typically much faster than necessary. [[Gearbox]]es are used to reduce speed and increase torque.  Some applications require the use of multi-shaft mixers, in which a combination of mixer types are used to completely blend the product.<ref>{{cite web |url=http://www.hockmeyer.com/products/high-viscosity-mixers/dual-triple-shaft-mixer-detail.html |title=High Viscosity Mixers: Dual and Triple Shaft Mixers |publisher=Hockmeyer.com |access-date=2017-06-23 |url-status=live |archive-url=https://web.archive.org/web/20170703141729/http://www.hockmeyer.com/products/high-viscosity-mixers/dual-triple-shaft-mixer-detail.html |archive-date=3 July 2017 |df=dmy-all }}</ref>

In addition to performing typical batch mixing operations, some mixing can be done continuously.  Using a machine like the Continuous Processor, one or more dry ingredients and one or more liquid ingredients can be accurately and consistently metered into the machine and see a continuous, homogeneous mixture come out the discharge of the machine.<ref>"Continuous Processor" http://www.dairynetwork.com/product.mvc/Continuous-Processor-0002</ref>  Many industries have converted to continuous mixing for many reasons.  Some of those are ease of cleaning, lower energy consumption, smaller footprint, versatility, control, and many others.  Continuous mixers, such as the twin-screw Continuous Processor, also have the ability to handle very high viscosities.{{Cn|date=March 2025}}

===Turbines===
A selection of turbine geometries and power numbers are shown below.
{| class="sortable wikitable" style="float:right; margin: 0 0 0.5em 1em"
|+ Selected Turbine Geometries and Power Numbers <br />
!Name
!Power number
!Flow direction
!Blade angle (degrees)
!Number of blades
!Blade geometry
|-
| [[Rushton turbine]] || 4.6 || Radial || 0 || 6 || Flat
|-
| Pitched blade turbine || 1.3 || Axial || 45–60 || 3–6 || Flat
|-
| Hydrofoil || 0.3 || Axial || 45–60 || 3–6 || Curved
|-
| Marine Propeller || 0.2 || Axial || N/A || 3 || Curved
|- style="background:#ccc;"
|colspan=6 |
|}

[[File:Mixing - flusso assiale e radiale.jpg|thumb|200px|Axial flow impeller (left) and radial flow impeller (right).]]

Different types of impellers are used for different tasks; for instance, [[Rushton turbine]]s are useful for dispersing gases into liquids, but are not very helpful for dispersing settled solids into liquid. Newer turbines have largely supplanted the Rushton turbine for gas–liquid mixing, such as the Smith turbine and Bakker turbine.<ref>{{cite web |url=http://www.bakker.org/cfm/bt6.htm |title=Asymmetric Blade Impeller |publisher=Bakker.org |date=1998-12-16 |access-date=2017-06-23 |url-status=live |archive-url=https://web.archive.org/web/20170814175906/http://www.bakker.org/cfm/bt6.htm |archive-date=14 August 2017 |df=dmy-all }}</ref> 
The power number is an empirical measure of the amount of torque needed to drive different impellers in the same fluid at constant power per unit volume; impellers with higher power numbers require more torque but operate at lower speed than impellers with lower power numbers, which operate at lower torque but higher speeds.{{Cn|date=March 2025}}

===Planetary mixer===
A ''planetary mixer'' is a device used to mix round products including [[adhesive]]s, [[pharmaceuticals]], [[food]]s (including [[dough]]), [[chemical]]s, [[solid rocket propellant]]s, [[electronics]], [[plastic]]s and [[pigment]]s. Planetary mixers are ideal for mixing and [[kneading]] viscous pastes (up to 6 million [[Poise (unit)|centipoise]]) under atmospheric or vacuum conditions. Capacities range from {{convert|0.5|uspt}} through {{convert|750|usgal}}. Many options including jacketing for heating or cooling, [[vacuum]] or pressure, vari speed drives, etc. are available. Planetary blades each rotate on their own [[Axis of rotation|axes]], and at the same time on a common axis, thereby providing complete mixing in a very short timeframe.<ref>[https://www.china-ashine.com/what-is-a-planetary-mixer-types-functions-how-to-work/ What is a Planetary Mixer? Types, functions & how they work], 28 October 2028</ref>

Large industrial scale planetary mixers are used in the production of [[solid rocket fuel]] for long-range [[ballistic missile]]s.  They are used to blend and homgenize the components of solid rocket propellant, ensuring a consistent and stable mixture of fuel & oxidizer.<ref>[https://mil.in.ua/en/news/israel-hits-ballistic-missile-production-facility-in-iran/ Israel hits ballistic missile production facility in Iran], Miliarynyi, 27 October 2028.</ref><ref>[https://newsukraine.rbc.ua/news/israeli-strike-cripples-iranian-missile-production-1729995076.html Israeli strike cripples Iranian missile production], RBC-Ukraine, 27 October 2024.</ref>

===ResonantAcoustic mixer===
ResonantAcoustic mixing (RAM) is able to mix, coat, mill, and sieve materials without impellers or blades touching the materials, yet typically 10X<ref name="a501">{{cite journal | last=Leung | first=Dennis H. | last2=Lamberto | first2=David J. | last3=Liu | first3=Lina | last4=Kwong | first4=Elizabeth | last5=Nelson | first5=Todd | last6=Rhodes | first6=Timothy | last7=Bak | first7=Annette | title=A new and improved method for the preparation of drug nanosuspension formulations using acoustic mixing technology | journal=International Journal of Pharmaceutics | publisher=Elsevier BV | volume=473 | issue=1-2 | year=2014 | doi=10.1016/j.ijpharm.2014.05.003 | pages=10–19}}</ref>-100X<ref name="z599">{{cite journal | last=Park | first=Jeong Hwa | last2=Bae | first2=Kyung Taek | last3=Kim | first3=Kyeong Joon | last4=Joh | first4=Dong Woo | last5=Kim | first5=Doyeub | last6=Myung | first6=Jae-ha | last7=Lee | first7=Kang Taek | title=Ultra-fast fabrication of tape-cast anode supports for solid oxide fuel cells via resonant acoustic mixing technology | journal=Ceramics International | publisher=Elsevier BV | volume=45 | issue=9 | year=2019 | doi=10.1016/j.ceramint.2019.03.119 | pages=12154–12161}}</ref> faster than alternative technologies by generating a high level of energy (up to 100 g) through seeking and operating at the resonant condition of the mechanical system - at all times.

ResonantAcoustic mixers from lab scale to industrial production to continuous mixing are used for energetic materials like [[explosive]]s, [[propellant]]s, and [[pyrotechnic composition]]s, as well as [[pharmaceuticals]], [[powder metallurgy]], [[3D printing]], [[rechargeable battery]] materials, and [[battery recycling]].<ref name="g610">{{cite journal | last=Beckel | first=Eric | last2=Oyler | first2=Karl | last3=Mehta | first3=Neha | last4=Khatri | first4=Natasha | last5=Marin | first5=John | last6=Shah | first6=Akash | last7=Cordaro‐Gioia | first7=Emily | last8=Decker | first8=Robert | last9=Grau | first9=Henry | last10=Stec | first10=Daniel | title=Primary Explosive Processing in the Resonant Acoustic Mixer | journal=Propellants, Explosives, Pyrotechnics | volume=46 | issue=5 | date=2021 | doi=10.1002/prep.202100008 | pages=697–704}}</ref><ref name="i584">{{cite journal | last=Smith | first=T. M. | last2=Thompson | first2=A. C. | last3=Gabb | first3=T. P. | last4=Bowman | first4=C. L. | last5=Kantzos | first5=C. A. | title=Efficient production of a high-performance dispersion strengthened, multi-principal element alloy | journal=Scientific Reports | publisher=Springer Science and Business Media LLC | volume=10 | issue=1 | date=2020-06-15 | doi=10.1038/s41598-020-66436-5 | doi-access=free | page=| pmc=7296023 }}</ref><ref name="f229">{{cite web | title=A Comparative Analysis of Cathode Stripping Methods for Direct Recycling of Spent Li-Ion Batteries | website=asmedigitalcollection.asme.org | url=https://asmedigitalcollection.asme.org/MSEC/proceedings-abstract/MSEC2023/87240/V002T06A036/1168773 | access-date=2024-11-11}}</ref>

===Close-clearance mixers===
There are two main types of close-clearance mixers: anchors and helical ribbons. Anchor mixers induce solid-body rotation and do not promote vertical mixing, but helical ribbons do. Close clearance mixers are used in the laminar regime, because the viscosity of the fluid overwhelms the inertial forces of the flow and prevents the fluid leaving the impeller from entraining the fluid next to it. Helical ribbon mixers are typically rotated to push material at the wall downwards, which helps circulate the fluid and refresh the surface at the wall.<ref>{{cite web |url=http://www.bakker.org/cfm/webdoc10.htm |title=Helical Ribbon Impeller |publisher=Bakker.org |date=1998-04-10 |access-date=2017-06-23 |url-status=live |archive-url=https://web.archive.org/web/20170814180054/http://www.bakker.org/cfm/webdoc10.htm |archive-date=14 August 2017 |df=dmy-all }}</ref>

===High shear dispersers===
{{main article|high-shear mixer}}
High shear dispersers create intense shear near the impeller but relatively little flow in the bulk of the vessel. Such devices typically resemble [[circular saw]] blades and are rotated at high speed. Because of their shape, they have a relatively low [[drag coefficient]] and therefore require comparatively little torque to spin at high speed. High shear dispersers are used for forming emulsions (or suspensions) of immiscible liquids and solid deagglomeration.<ref>{{cite web |url=http://www.hockmeyer.com/technical/publications/73-dispersion-tips-help.html |title=A Practical Guide to High Speed Dispersion |date=18 December 2012 |publisher=Hockmeyer.com |access-date=2017-06-23 |url-status=live |archive-url=https://web.archive.org/web/20170610072344/http://www.hockmeyer.com/technical/publications/73-dispersion-tips-help.html |archive-date=10 June 2017 |df=dmy-all }}</ref>

===Static mixers===
{{main article| static mixer}}
Static mixers are used when a mixing tank would be too large, too slow, or too expensive to use in a given process.

===Liquid whistles===
{{main article|Liquid Whistle}}
Liquid whistles are a kind of [[static mixer]] which pass fluid at high pressure through an orifice and subsequently over a blade.<ref>{{cite journal|last1=Ryan|first1=David|last2=Simmons|first2=Mark|last3=Baker|first3=Michael|date=2017|title=Determination of the flow field inside a Sonolator liquid whistle using PIV and CFD|journal=Chemical Engineering Science|volume=163|pages=123–136|doi=10.1016/j.ces.2017.01.035|bibcode=2017ChEnS.163..123R |doi-access=free}}</ref> This subjects the fluid to high [[Turbulence|turbulent]] stresses and may result in [[Mixing (physics)|mixing]], [[emulsification]],<ref>{{cite journal|last1=Ryan|first1=David|last2=Baker|first2=Michael|last3=Kowalski|first3=Adam|last4=Simmons|first4=Mark|date=2018|title=Emulsification using a "Sonolator" liquid whistle: A new correlation for droplet size from pilot-scale experiments|journal=Chemical Engineering Science|volume=189|pages=369–379|doi=10.1016/j.ces.2018.06.004|bibcode=2018ChEnS.189..369R |url=http://pure-oai.bham.ac.uk/ws/files/50011638/Ryan_Emulsification_Chemical_Engineering_Science.pdf|doi-access=free}}</ref><ref>{{cite thesis|type=EngD.|last=Ryan|first=David|date=2015|title=Investigation of Fluid Dynamics and Emulsification in Sonolator Liquid Whistles|publisher=University of Birmingham, UK|url=http://etheses.bham.ac.uk/5696/|access-date=1 Sep 2015}}</ref> deagglomeration and disinfection.

===Other===
{{More citations needed section|date=March 2025}}
[[File:Paddle-mixer.jpg|thumb|Industrial Paddle Mixer]]
[[Image:Paddle-Mixers-Logo.gif|thumb|200px|Industrial Paddle Mixer.]]
[[Image:V-Blender-Logo.gif|thumb|200px|Industrial V Blender.]]
[[Image:Ribbon-Blender-Logo.gif|thumb|200px|Industrial Ribbon Blender.]]
[[Image:Double-Cone-Blender-Logo.png|thumb|200px|Industrial Double Cone Blender.]]
[[Image:High-Shear-Mixers-Granulators-Logo.gif|thumb|200px|Industrial High shear Mixer/Granulator.]]
[[Image:Drum-Blender-Logo.png|thumb|200px|Drum-Blender]]
[[File:Double shaft mixer.jpg|thumb|Double shaft mixer for high-viscosity materials]]
*Ribbon Blender
*:Ribbon blenders are very common in process industries for performing dry-mixing operations. The mixing is performed thanks to 2 helix (ribbon) welded on the shafts. Both helix move the product in opposite directions thus achieving the mixing<ref>{{cite web |url=https://www.powderprocess.net/Equipments%20html/Ribbon_blender.html |title=Powder Mixer - Ribbon blender - Design calculation and key operation parameters |access-date=2018-02-16 |url-status=live |archive-url=https://web.archive.org/web/20180216205355/https://www.powderprocess.net/Equipments%20html/Ribbon_blender.html |archive-date=16 February 2018 |df=dmy-all }}</ref> (see picture of ribbon blender).
*V Blender
*Twin-Screw Continuous Blender<ref>{{cite journal|last1=Nagy B|display-authors=etal|title=In-line Raman spectroscopic monitoring and feedback control of a continuous twin-screw pharmaceutical powder blending and tableting process|journal=Int. J. Pharm.|date=2017|volume=530|issue=1–2|pages=21–29|doi=10.1016/j.ijpharm.2017.07.041|pmid=28723408}}</ref>
*Continuous Processor
*Cone Screw Blender
*Screw Blender
*Double Cone Blender
*Double Planetary
*[[High Viscosity Mixer]]
*Counter-rotating
*Double & Triple Shaft
*Vacuum Mixer
*High Shear Rotor Stator
*[[Impinging mixer]]
*Dispersion Mixers
*Paddle
*Jet Mixer
*Mobile Mixers
*Drum Blenders
*Intermix mixer
*Horizontal Mixer
*Hot/Cold mixing combination
*Vertical mixer
*[[Turbomixer]]
*Banbury mixer
*:The ''Banbury mixer'' is a [[brand]] of internal [[Batch production|batch]] mixer, named for inventor [[Fernley H. Banbury]].  The "Banbury" trademark is owned by [[Farrel Corporation]]. Internal batch mixers such as the Banbury mixer are used for mixing or compounding [[rubber]] and plastics. The original design dates back to 1916.<ref>{{cite web|url=http://www.accessmylibrary.com/coms2/summary_0286-29505973_ITM|title=AML - support.gale|website=www.accessmylibrary.com|access-date=26 April 2018}}</ref> The mixer consists of two rotating [[spiral]]-shaped blades encased in segments of cylindrical housings. These intersect so as to leave a ridge between the blades. The blades may be cored for circulation of heating or cooling. Its invention resulted in major labor and capital savings in the tire industry, doing away with the initial step of roller-milling rubber.<ref>{{cite book|url=https://books.google.com/books?id=XSybNRCfYn0C&dq=%22Banbury+mixer%22+history&pg=PA336|title=The Labor History Reader|first=Daniel J.|last=Leab|date=26 April 1985|publisher=University of Illinois Press|access-date=26 April 2018|via=Google Books|isbn=9780252011986}}</ref> It is also used for reinforcing fillers in a resin system.