SEPARATORS - Walchandnagar Industries · Sturtevant Whirlwind, Raymond Double Whizzer,...

A Tradition of Engineering Excellence

SEPARATORSIN TECHNICAL COLLABORATION WITH

MAGOTTEAUX INTERNATIONAL S. A,, BELGIUM

THE STURTEVANTSD - HIGH EFFICIENCY CLASSIFIER

Sturtevant

Examples:

Sturtevant Whirlwind, Raymond Double

Whizzer, Pfeiffer-Heyd, Polysius Turbopol,

Drawbacks:

1. Distribution is below the selecting zone. A lot

of material falls down before being selected.

2. No control over airflow and very inefficient

built in fan.

3. Poor cycloning effect in the outer casing:

A lot of fines are returned, cross the stream

of falling coarse particles, are caught and

returned to the mill.

The larger the separator, the worse the

cycloning efficiency in the outer casing.

4. The selection zone is a horizontal ring

delimited by the selection plates. The

selecting action varies depending on

whether the particles hit the outer part of the

ring orthe inner part.

5. Narrow range of fineness adjustment. The

non-adjustable speed separators in

particular will require the removal or

reinstallation of selection blades for each

cement quality.

SEPARATORS : THE THREE GENERATIONS

THE FIRST GENERATION

THE SECOND GENERATION

Examples:

KHD (zub models) O & K Polysius Cyclopol

Advantages:

1. With an external fan and small cyclones,

most of the drawbacks of the first

generation are solved. The external fan has

a better efficiency and can be precisely

controlled.

2. The external cyclones remove most of the

fines from the air going back to the

separator. However, the selecting zone is

still a ring of selection blades with the above

THE THIRD GENERATION

The third generation appeared

in the first half of the eighties

(1984) with Onoda (O'sepa) and

Sturtevant. Sturtevant was already

using the same principle on

separators used in ultra-fine

selection. The results were so

much better that almost every mill

manufacturer developed his own

version:

Sturtevant O&K

FLS KHD

Pfeiffer FCB

Onoda Polysius

T h e m a i n i m p r o v e m e n t

compared to the second generation

is the distribution. It is generally

done on the top of the cylindrical

selection zone. The cylindrical

shape gives more time for the fine

particles to be separated from the

falling material. As a result, very

few fines are returned to the mill

and the tromp curves are better and

have a very low by-pass.

The Sturtevant SD separator is

the result of over 20 years of

research and development. It

combines many technological

features designed to maximize

classification and efficiency

performance at lowest operating

and maintenance costs.

The first patent application for

this separator was submitted in

1974 and the first production

machine was sold in 1984. Ever

since the first installation, efforts

have been made to continuously

improve the machine.

Examples:

Sturtevant Whirlwind, Raymond Double

Whizzer, Pfeiffer-Heyd, Polysius Turbopol,

Drawbacks:

1. Distribution is below the selecting zone. A lot

of material falls down before being selected.

2. No control over airflow and very inefficient

built in fan.

3. Poor cycloning effect in the outer casing:

A lot of fines are returned, cross the stream

of falling coarse particles, are caught and

returned to the mill.

The larger the separator, the worse the

cycloning efficiency in the outer casing.

4. The selection zone is a horizontal ring

delimited by the selection plates. The

selecting action varies depending on

whether the particles hit the outer part of the

ring orthe inner part.

5. Narrow range of fineness adjustment. The

non-adjustable speed separators in

particular will require the removal or

reinstallation of selection blades for each

cement quality.

SEPARATORS : THE THREE GENERATIONS

THE FIRST GENERATION

THE SECOND GENERATION

Examples:

KHD (zub models) O & K Polysius Cyclopol

Advantages:

1. With an external fan and small cyclones,

most of the drawbacks of the first

generation are solved. The external fan has

a better efficiency and can be precisely

controlled.

2. The external cyclones remove most of the

fines from the air going back to the

separator. However, the selecting zone is

still a ring of selection blades with the above

THE THIRD GENERATION

The third generation appeared

in the first half of the eighties

(1984) with Onoda (O'sepa) and

Sturtevant. Sturtevant was already

using the same principle on

separators used in ultra-fine

selection. The results were so

much better that almost every mill

manufacturer developed his own

version:

Sturtevant O&K

FLS KHD

Pfeiffer FCB

Onoda Polysius

T h e m a i n i m p r o v e m e n t

compared to the second generation

is the distribution. It is generally

done on the top of the cylindrical

selection zone. The cylindrical

shape gives more time for the fine

particles to be separated from the

falling material. As a result, very

few fines are returned to the mill

and the tromp curves are better and

have a very low by-pass.

The Sturtevant SD separator is

the result of over 20 years of

research and development. It

combines many technological

features designed to maximize

classification and efficiency

performance at lowest operating

and maintenance costs.

The first patent application for

this separator was submitted in

1974 and the first production

machine was sold in 1984. Ever

since the first installation, efforts

have been made to continuously

improve the machine.

MECHANICAL FEATURES

SD STURTEVANT

Lower power consumption

Low pressure drop

Proven gear unit

Bearings designed for low maintenance

No wear on drive shaft

Single volute air entry

State of the art dynamic seal

Trouble free rods system

Easy access

Easy overall maintenance

Classification Principle State - of- the - Art Dynamic Seal

Material Feed Chute

Single Volute Air Inlet

Rejector Cage Assembly

(Rotating)

Fines Chamber

Rejects Chamber

Gear Unit Casing

Distribution Plate

(Rotating)

Louvre Assembly

Tangential Air &

Fines Outlet Volute

MECHANICAL FEATURES

SD STURTEVANT

Lower power consumption

Low pressure drop

Proven gear unit

Bearings designed for low maintenance

No wear on drive shaft

Single volute air entry

State of the art dynamic seal

Trouble free rods system

Easy access

Easy overall maintenance

Classification Principle State - of- the - Art Dynamic Seal

Material Feed Chute

Single Volute Air Inlet

Rejector Cage Assembly

(Rotating)

Fines Chamber

Rejects Chamber

Gear Unit Casing

Distribution Plate

(Rotating)

Louvre Assembly

Tangential Air &

Fines Outlet Volute

MINIMUM POWER CONSUMPTION

High efficiency air separation implies the separator vent air fan. For this reason, the

manipulation of air as a means of separating Sturtevant SD separator cage implements the

small particles from the larger particles that use of rods as the rejector mechanism instead

appear in a closed circuit grinding system. The of the blades used by other manufactures, thus

only two moving components that act on the air minimizing the "fan effect". The concept of using

are an auxiliary air fan (responsible for the rods was not agreed upon without realizing the

overall movement of air and material effect on the separation process.

throughout the separator) and an integral As a matter of fact, our lab test indicate that rotating rejector cage (responsible for the separation efficiency of a cage utilizing rods screening the larger particles while allowing the is equivalent to the blades when making a smaller particles to be transported by the flow product below with a fitness below 9000 blaine. of air) But most importantly, as the use of rods

The rotating rejector cage, by nature of the minimizes the fan effect of the cage, the power

direction of auxiliary air flowing through it, consumption of both the auxiliary fan and the

produces a "fan effect" which works against the separator cage is significantly reduced.

REJECTOR CAGE DESIGN

STATE OF ART DYNAMIC SEAL

The Sturtevant SD separator is provided The effectiveness of the seal is proven by the

with a dynamic seal between the rotating cage excellent residues obtained (less than 5%on

and the static fines chamber. The selection rods #325 at 3500 blaine, less than 1% at 4000

are extended below the bottom flange of the blaine in the most cases). The seal itself is easily

cage so as to be located in front of the seal area, adjusted by shimming the classifier gear unit

hereby minimizing coarse product residues. and it is partically maintenance free.

SINGLE VOLUTE AIR INLET

The Sturtevant SD single inlet volute is classification. It has been observed that

designed to ensure an even distribution of air multiple inlets can lead to an uneven

around the entire circumference of the rejector distribution of air. However, if it were necessary

cage. to incorporate a multiple entry inlet volute, the

Sturtevant SD configuration would easily allow This is the fundamental objective required in for it.order to achieve high efficiency air

TANGENTIAL AIR AND FINES OUTLET VOLUTE

The Sturtevant SD fines chamber volute minimizing the pressure drop across the

design allows the outlet ducts(s) to be tangent separator. This configuration allows for both

to the fines chamber, thus including a smooth single and multiple outlet designs.

flow of air and fine material and subsequently

WEAR RESISTANT PARTS FOR THE STURTEVANT-SD

High material air loading areasi.e. fines chamber, outlet ducts and air inlet chambers.

Distributor plate

Louvres

Tailings Cone

Rotor Support Posts

Basalt or Ceramic (alumina Oxide) liners

1/4" Abrasalloy Steel

Abrasion Resistant Steel (AR Plate)

Ring Liners

Extra Heavy Pipe Liners

LOCATION MATERIAL