Dispersing Impellers:

Generally speaking, a dispersing blade is a blade that fits onto a disperser which is built to run at high speeds forming a vortex and creating shear on the surface of the blade. The blades are flat and bolt onto the shaft using a center bore with pins/bolts or a center bore with keyway sandwiched between stiffening plates.  They can be found with welded collars and set screws but this can be very dangerous. They can be found with center bores and no pins or no keyway but they can then spin unless there is a strong compression plate type fitting or reverse threads. Some metal blades can be manufactured in a heavier gauge depending on the style.

For more detailed information on this subject, please visit the Education & Information Section.

Accessories for Dispersing Blades:

  • Stiffening plates are needed for steel blades to delay fatigue caused by a fluttering effect when the shaft is running at high speeds;
  • Stiffening plates are needed for plastic blades to prevent the holes and/or keyway from stretching;
  • Blade guards should be used for stationary steel impellers to prevent personnel from getting cut or always have the idle blade in an empty drum or tank;

For a quote or discussion, complete the IMPELLER BLADE SPECIFICATION FORM.

Dispersing Impellers:

Generally speaking, a dispersing blade is a blade that fits onto a disperser which is built to run at high speeds forming a vortex and creating shear on the surface of the blade. The blades are flat and bolt onto the shaft using a center bore with pins/bolts or a center bore with keyway sandwiched between stiffening plates.  They can be found with welded collars and set screws but this can be very dangerous. They can be found with center bores and no pins or no keyway but they can then spin unless there is a strong compression plate type fitting or reverse threads.

Dispersing impellers are designed to run at a 4000-6000 fpm (feet/minute) tip speed which is calculated based on the blade geometry of 1/3 diameter of the tank and 1 hp/10 gallons with the height of the liquid level being equal to the diameter of the tank.

Metal blades can only spin in one direction. The impeller will be marked with an arrow showing the direction.  If put on backwards they will rip.

Polyblades are symmetrical and work running in either direction.  When one side is worn they can be turned over essentially installing a new blade.

Each impeller design has an optimum tip speed range. The formula for calculating this tip speed is BLADE DIAMETER in inches divided by 12; multiply by 3.14; multiply by shaft rpm. Some of the guidelines are as follows:

    • Steel tooth style dispersing blades                                5000-5500 fpm
    • Steel tooth style dispersing with pumping                   4000-4500 fpm
    • Steel tooth style with low shear pumping                    4000-4500 fpm
    • Polyblades                                                                     4000-4500 fpm
    • Ring Blade                                                                    5800-6000 fpm
    • The liquid level should be equal to the tank diameter
  • Each blade style has an optimum diameter to tank ratio
    • Steel Blades, low to medium viscosity                        33% tank diameter
    • Steel blades, medium to high viscosity                       50% tank diameter
    • Polyblades, low viscosity                                             25% tank diameter
    • Polyblades, medium viscosity                                     28% tank diameter
    • Polyblades, high viscosity                                           33-50% tank diameter
    • Ring Blade                                                                   25-40% tank diameter
  • Each blade style has an optimum height position in the tank
    • Steel blades                                                                 ½ blade diameter off tank floor
    • Steel pumping blades & Polyblades                           2/3-1 blade diameter off the tank floor
  • Dispersers generally require 1 hp/10 gallons but this is also product dependent and batch size dependent;
  • During operation, the blade should never be exposed more than where it meets the shaft during the rolling donut type of vortex;
  • Impellers should be centered in the tank or just slightly off-set;
  • Baffles cause an interference with the vortex and should not be used with dispersers.

Accessories for Dispersing Blades:

  • Stiffening plates are needed for steel blades to delay fatigue caused by a fluttering effect when the shaft is running at high speeds;
  • Stiffening plates are needed for plastic blades to prevent the holes and/or keyway from stretching;
  • Blade guards should be used for stationary steel impellers to prevent personnel from getting cut or always have the idle blade in an empty drum or tank;

METAL DISPERSING IMPELLERS

TYPE 1/ANGLED TOOTH BLADE/COWLES AS WELL AS TYPE 6/SQUARE TOOTH BLADE/F STYLE:

Popular blade for dispersion work. Primarily a high shear blade. There are many designs that are efficient and have proven to be an excellent blade for shearing. There are newer technologies that provide more pumping with shear. Stock sizes from 1″ and larger. We recommend sizes of 1.5″ and larger. The variations on the tooth do not appear to make a significant difference but the number of teeth can.

  • Keeps air entrainment to a minimum
  • Gets very sharp with use
  • Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
  • Requires Stiffening Plates
  • Can be hard coated for longer life
  • Only goes in 1 direction
  • 5000-5500 fpm tip speed

Type 1 Cowles Angle Tooth

Get a Quote

Type 6 Hockmeyer Square Tooth

Get a Quote

TYPE 1S: SERRATED TEETH ANGLED TOOTH BLADE

This is similar to a Type 1 or 6 with serrated edges at the top of the teeth. Many customers like this blade but Norstone testing indicates that if the material is not low viscosity, it can entrain air and/or create foam.

  • Gets very sharp with use
  • Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
  • Requires Stiffening Plates
  • Can be hard coated for longer life
  • Only goes in 1 direction
  • 5000-5500 fpm tip speed

Type 1S High Speed Shearing Blade with Seratted Teeth

Get a Quote

TYPE 2/TYPE 2G: HIGH VANE BLADE/G STYLE

High pumping low shear action. This blade is for mixing on a high speed disperser with minimal shear and heat build-up. This blade is popular in the mixing and let down of coatings but also to assist high speed shear blades processing high viscosity materials.  It is available in sizes from 2″ and up.

  • Gets very sharp with use
  • Draws more amps than Type 1 or Type 6
  • Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
  • Requires Stiffening Plates
  • Can be hard coated for longer life
  • Only goes in 1 direction
  • 4500-5500 fpm tip speed

Type 2 Low Shear High Speed

Get a Quote

Type 2G Low Shear High Speed

Get a Quote

TYPE 3: COMBINATION BLADE/E STYLE

This blade offers a combination of high shear along with excellent batch movement and cutting in fibrous or higher viscosity materials. It is excellent for high solids as well. Popular when dispersing nitrocellulose. Available in sizes from 2″ and up.

  • Shears, Pumps and Cuts
  • Gets very sharp with use
  • Excellent for chips, fibers, cellulose, resins, high viscosity & high solids
  • Draws more ampts than Type 1 or Type 6
  • Requires Stiffening Plates
  • Can be hard coated for longer life
  • Only goes in 1 direction
  • 5000-5500 fpm tip speed

Type 3 or E Combination Blade for Shearing, Cutting, Pumping

Get a Quote

TYPE 4: AGGRESSIVE SHEAR BLADE

This blade works well on materials difficult to de-agglomerate but draws higher amps and surges. It is available in sizes from 2″ and up.

  • High Shear Blade with larger teeth for more aggressive action;
  • Better at pumping than standard high shear blades;
  • Not very popular due to its strong surging and power draw
  • Gets very sharp with use.
  • Requires Stiffening Plates
  • Only goes in 1 direction
  • 5000-5200 fpm tip speed

Type 4 Aggressive Large Tooth

Get a Quote

TYPE 5: PICK BLADE

This blade is perfect for cutting in or shredding rubber, waxes and other soft materials that tend to gum up on standard impellers. Unique design features a knife (or pick) extending out from the blade, alternating with vertical teeth. This blade is available in sizes from 2″ and up.

  • Gets very sharp with use
  • Blade and teeth can bend if heavy product dropped on it or hits side wall of tank
  • Requires Stiffening Plates
  • Only goes in 1 direction
  • 5000-5500 fpm tip speed

Type 5 Knife Edge Cutting & Angled Tooth Dispersing

Get a Quote

TYPE 7M: METAL VERSION OF THE TYPE 7 DHS POLYBLADE WITH DIAMOND TEETH AND SCOOPS

  • Diamond shaped teeth in between scoops
  • 6/2:  6 scoops with 2 teeth in between
  • 6/3: 6 scoops with 3 teeth in between
  • 9/1 : 9 scoops with 1 tooth in between
  • Aggressive shearing with pumping to help move the fluid more efficiently
  • Similar shear to Type 1 & Type 6 with the addition of pumping
  • Bi-directional
  • Available in Aluminum, Stainless steel, Carbon Steel
  • Only use if metal is preferred over polymers
  • Does NOT need stiffening plates
  • Excellent for hard agglomerates and chunks like press cake
  • Excellent for high temperature applications above 450F
  • Can also be made available in ceramic

Type 7M-DHS Metal Version of Polyblade in Aluminum, Stainlless or Carbon Steel

Get a Quote

TYPE 11: DISPERSING IMPELLER WITH TOP PUMPING LOUVRES

Type 11: The louvers formed in the plane of the blade provide maximum pumping action giving positive over all material movement with excellent top to bottom flow. They are excellent for lifting quick settling materials off the bottom of a tank in medium to high viscosity materials. The ITT is for high shear and agitation. High positive material movement. Recommended where high shear is required for a rapid and smooth blend or when high shear is not required but is not detrimental. This Impeller should be 1/2 – 1 full diameter of the bottom of the tank with at least twice as much above the blade or it will suck in air.

Rules for the Type 11 blade are as follows:

  • 1/2 – 1 full blade diameter off bottom with 1.5 – 2 blade diameters of fluid above the blade;
  • 4000-4500 fpm tip speed;
  • Impeller size should be 1/3 diameter of tank for standard materials; high viscosity can take up to 50% the diameter of tank.
  • Only goes in one direction

Type 11 Conn Pumping & Dispersing Blade

Get a Quote

TYPE 11S: DISPERSING IMPELLER WITH TOP & BOTTOM PUMPING LOUVRES

Type 11S: The louvers formed in the plane of the blade provide maximum pumping action giving positive over all material movement with excellent all around flow as the louvres are flat planes piercing both above and below the blade. Excellent for lifting quick settling materials off the bottom of a tank in medium to high viscosity materials. This Impeller should be 1/2 – 1 full diameter of the bottom of the tank with at least twice as much above the blade or it will suck in air.

  • Impeller size should be 1/3 diameter of tank for standard materials; high viscosity can take up to 50% the diameter of tank.
  • Available with serrated teeth
  • Has rectangular pumping louvres which alternate 1-up & 1-down
  • A lot of edges that can get very sharp
  • Great for cutting
  • Works for a wide range of viscosities
  • Might aerate some products and cause foaming
  • Stiffening plates are required
  • Can be difficult to clean;
  • Only goes in one direction
  • Excellent for chopping and cutting;
  • 4000-4500 fpm tip speed

Type 11S Cutting, Pumping & Dispersing with serrated teeth

Get a Quote

TYPE 25/D BLADE/MULTI LAYER RING STYLE

Also known as a Ring Blade, this impeller consists of three plates welded together with “cutting teeth” in between. Provides excellent shear using the Venturi principal. Requires a 5800 fpm +/- 5% tip speed. Trial sizes available.
Rules for the D blade:

  • 1/2 – 1 full blade diameter off bottom with minimum of 2 blade diameters of fluid above the blade.
  • Most expensive blade but provides energy close to that of a rotor stator
  • Can be challenging to clean
  • Can clog with large agglomerates
  • Works in one direction only
  • Blade size should be ¼-1/3 diameter of tank for standard materials; higher viscosities can use up to 40% the diameter of tank.
  • Viscosity Range: 1,000 CPS to 10,000 CPS. It has been used up to 50,000 CPS and lower than 1,000 CPS depending upon specific gravity
  • Does not require stiffening plates
  • 5800 fpm-6000 +/- 5% tip speed
  • Confirm the disperser can travel at tip speeds this high

Type 25 5800 fpm High Speed Shearing & Homogenizing

Get a Quote

TYPE 28/MULTI LAYER RING STYLE

A copy cat of the D blade but more limited sizes. Also known as a Ring Blade, this impeller consists of three plates welded together with “cutting teeth” in between. Provides excellent shear using the Venturi principal. Requires a 5800 fpm +/- 5% tip speed. Trial sizes available.
Rules for the D blade:

  • 1/2 – 1 full blade diameter off bottom with minimum of 2 blade diameters of fluid above the blade.
  • Most expensive blade but provides energy close to that of a rotor stator
  • Can be challenging to clean
  • Can clog with large agglomerates
  • Works in one direction only
  • Blade size should be ¼-1/3 diameter of tank for standard materials; higher viscosities can use up to 40% the diameter of tank.
  • Viscosity Range: 1,000 CPS to 10,000 CPS. It has been used up to 50,000 CPS and lower than 1,000 CPS depending upon specific gravity
  • Does not require stiffening plates
  • 5800-6000 fpm +/- 5% tip speed
  • Confirm the disperser can travel at tip speeds this high

Type 28 CSI Shearing Rings

Get a Quote

TYPE 50/SHEARING DISK

  • Good for shear with shear sensitive products;
  • Gentle; use for when product deagglomeration is required but any type of particle destruction or deformation is not tolerated;
  • Available in any material of construction.
  • 5000-6000 fpm tip speed

Type 50 Shearing Disk

Get a Quote

MIXING IMPELLERS

Generally speaking, a mixing blade is a blade that fits onto a mixer which runs at low speed up to 3000 rpm

View Product Line

Polyblade Dispersing Impellers

The Polyblade is far safer than a metal blade, dual sided, lasts longer and handles higher solids and higher viscosities more efficiently.

View Product Line

Laboratory Impellers

Most of the styles found in both the Mixing and Dispersing sections are available in laboratory size.  Some start as small as 1” while others will be 1.5” or 2.0” depending on the style.

View Product Line

ACCESSORIES

There are a few accessories for dispersing impellers that are critical for the impellers to run correctly and/or operate safely.

View Product Line

DESCRIPTIONS

 

View Product Line