DIS

PE

RSI

NG

MIX

ING

AG

ITA

TIN

G

As one of the world's leading suppliers of processing plants for

the paper and chemical industry, GAW draws on more than 40

years of experience. During this period, a strategy of continuous,

consistent and on-going development has been pursued. The

latest knowledge from science and technology has constantly

been integrated into GAW's mechanical engineering and mate-

rials and process technology, including GAW's own experience

in developing applications and solutions. Thanks to its experien-

ce, the company is able to find optimum solutions for its clients'

specific needs. Though one of the core areas here has been the

dispersing, mixing and agitating processes. This experience is

supported with a distinct product program.

THE COMPANY

DIS

PER

SIN

GM

IXIN

G A

GIT

ATIN

GDispersing, mixing and agitating processes form a central and

quality-defining step within chemical process technology. The goal

of these process steps is the production of uniform and homoge-

nous mixtures – as intermediate or final products – of various raw

materials. Since the characteristics of raw and final products vary

widely, the ways of achieving this goal are multiple.

The main characteristics common to all these processes are:

• optimum usage of energy

• constant and reproducible qualities

• scalability

• high efficiency

• gentle treatment of the materials

• optimum process integration

Due to these factors and the large number of industrial applicati-

ons, in the end every solution must be a successful compromise.

Various mixing and agitating systems shown as a principle flow diagram of a coating kitchen.

Round view of the coating kitchen PM/SM 11 at SAPPI Gratkorn

DIS

PER

SIN

G

ROTOR/STATOR DISPERSING AGGREGATE

Application• production of finest dispersions and emulsions• dispersion of fillers, pigments and complex pigment mixtures• dispersion of talc and carbonates• dry metering of viscosity-adjusting components = HIGH SOLIDS PRODUCTS

Construction characteristics• rotor-stator principle• top or bottom driven• simple reconstruction of existing installations• service-friendly construction

Advantages• optimal usage of energy and high efficiency• short batch times combined with high product quality • processing of high solid contents with reproducible particle sizes• processing high level and complex formulas

TOOTHED DISPERSION DISC

Applications• production of simple dispersions and emulsions• dispersion of pigments and various pigment mixtures• preparation of simple product formulas

Construction characteristics• top or bottom driven• simple, robust construction

Advantages• reasonable costs, universal suitability• low maintenance • low operational costs

Efficient dispersing and mixing are essen-

tial for the production of high quality pro-

ducts and the runability of further production

systems.

GAW dispersion systems gua-

rantee the required viscosities,

solid contents and rheologic

characteristics of homoge-

nous dispersions and emulsi-

ons.

DISPERSION- OR

TOOTHED DISC

For simple dispersion and emulsion processes, the classic,

inexpensive dispersion, or toothed disc is used. The individual

design of the disc, the number of rotations per minute, as well

as the position of the components within the tank, ensure opti-

mal results.

GAW-DISPERSION AGGREGATE

The GAW dispersion aggregate is based on the principle of

kinetic energy. The rotor-stator system causes dispersion

of the components. This results in unusually low batch

times, which in turn mean low energy consumption and

optimal particle size distribution. Additionally, the need for

binders and additives is reduced significantly. The localized

transformation of energy within the area of rotor and stator

avoids the intake of air into the media.

GAW-dispersion aggregate

Dispersion or toothed disc

DISPERSION DISC AND -AGGREGATE

VST-DISPERSION AGGREGATE

Applications• dispersion of pigment slurries with high solid contents • preparation of complex product formulas• direct metering of dry components

Construction characteristics• bottom driven rotor-stator system• infinitely adjustable overlapping of rotor and stator• simple upgrading of existing installations• 5 sizes

Advantages• processing of shear-sensitive products using variable stator position • improved particle size distribution and homogeneity due to variable shear

ratio combined with adjustable product circulation• saves energy through faster metering of components combined with even

shorter batch times• significant savings of binders and additives in combination with highest solid

contents and optimal viscosities• avoidance of air intake leads to reduction of air content of the productD

ISPE

RSI

NG

The VST-dispersion system is a product of GAW’s constant pro-

duct development research. The VST-system combines the

advantages of conventional dispersion methods such as

rotor/stator system, toothed disc and vortex propeller.

VST is an acronym for VARIABLE SHEAR TECHNOLOGY and

is based on the infinite adjustability of the overlapping of rotor

and stator during the operation.

This makes it possible to use the optimum combinati-

on of product circulation and shear ratio for each

respective application and formula. The VST-

system ensures the optimal processing of com-

plex product formulas with highest demands on

quality and stability of the processed products.

GAW-VST-DISPERSION SYSTEM

GAW-VST-dispersion system

DISPERSING MACHINES

Applications• production of various dispersions and emulsions• preparation of fillers and recycling components• preparation of coating colors and pigment slurries

Construction characteristics• chassis type or suspended type • temperature controlling tank walls (optional)• stream breaking devices (optional)• integration of GAW quality loop (optional)• robust design and excellent dynamic stability• production machines from 500 to 16.000 liters• laboratory machines from 5 to 25 liters

Advantages• individual integration into existing facilities • high production capacity with compact design machines• simple installation on weighing systems for metering monitoring• simple integration of quality control equipment D

ISPE

RSI

NG

GAW dispersing machines combine tailor-made tank design

with state-of-the-art technologies in the design of dispersion

systems. Multiple optional features such as metering monito-

ring, temperature control and quality loop ensure the achieve-

ment of the quality and capacity targets.

For trials and laboratory purposes, GAW offers laboratory

dispersing machines, which correspond to the construction

principles of the production machines. Trial results are directly

applicable to production.

DESIGNS

Dispersing machinesuspended type

Dispersing machinetop driven

Dispersing machinechassis-type

Dynamic mixing includes many basic functions of process tech-

nology, such as stirring, mixing, dissolving, homogenizing etc.

GAW offers tailor-made agitating and mixing systems for the

various applications (i.e. slurry make-down stations, starch

make-down systems, waste water sumps, etc.).

The optimized process and control technology ensures the

maximum economic efficiency.

Depending on the mixing task, different agitating and mixing

systems are used. Size and shape of the mixing elements are

adapted to the shape of the tank, the chemical and physical

characteristics of the process media, and the

process requirements.

DYNAMIC MIXING

Waste water sump

Slurry make down station

Dynamic inline mixer

For special mixing processes, which need to run continuously

and within a closed system, GAW offers inline mixers. These

are offered as dynamic and static mixers.

Dynamic mixers have a separately-driven mixing aggregate

(turbine, propeller etc) which simultaneously mixes and pumps

the process media within a piping system or a reaction tank.

The static inline mixer consists of several stationary left and

right turning elements within a pipe. The process media flow is

divided by these elements, to partial flows which completely

and continuously mix the media by means of the resulting rota-

tion effect.

GAW offers inline mixers with pipe diameters from 25 mm to

400 mm.

INLINE MIXING

Static inline mixer

Dynamic inline pipe mixer

AGITATORS

Applications• agitators for storage tanks• agitators for small and medium-sized tanks• agitators for exact process control

Construction characteristics• shaft bearing inside the drive gear box • welded construction, no bolted connections within the shaft• fixing of the agitating elements (blades, paddles or beaters) with

clamps bolted to the shaft• centering turbine and centering rings prevent oscillation of big agitators • smooth-starting devices for big agitators• agitators for tanks of 1 m3 up to 2000 m3

Advantages• optimal energy use• compact, low-maintenance construction• construction and design prevent sedimentation • tailor-made agitating elements• optimal adaptation to the production processA

GIT

ATIN

G A

ND

CIR

CU

LAT

ING

For the tasks of stirring and agitating GAW offers a wide

variety of tanks and special constructions with agitators.

Agitators are used to avoid sedimentation in tanks and to keep

homogenous mixtures. To achieve this, it is important to keep

the complete media in continuous movement, in order to main-

tain a constant quality of the process media for longer periods.

Depending on the actual purpose of the process, GAW uses

vertical, horizontal, or diagonal agitators with individual-

adapted agitation elements.

Special attention is paid to the design of agitators for special-

purpose machinery, where process media are dissolved or boi-

led, and many different chemical reactions take place.

Besides the optimal technological design of tank and agitating

elements, GAW gives special care to the sealing of the agita-

tors. Depending on the safety needs and regulations for the

processes, these often require special constructions.

TANK CONSTRUCTION AND SPECIAL PURPOSE MACHINERY

Special purpose machinery

With regard to quality and complexity, the demands placed on

process technology are constantly increasing. The precise

usage of the appropriate components is a basic condition if a

process is to be economical.

With GAW metering and charging systems, both dry and

liquid products are metered precisely according to the speci-

fied formulas, and added to the respective production process.

Depending on the basic products and the degree of accuracy

required, the metering is done via mass-flow-meters, weighing

systems, metering screws, etc. Selection criteria are the chemi-

cal and physical characteristics of the products (delivery form,

concentration, electrical conductivity, specific gravity etc.).

In addition, the automatic control of the quantities of compo-

nents used offers optimal support for logistics and production

planning.

METERING AND CHARGING

The demands made on modern process technology with

regard to production, quality and environmental protection

requirements are constantly growing. Efficient production

means producing high quality products at increased produc-

tion speeds.

To meet this demand of high quality, and to detect any quality

irregularities, GAW offers an on-line quality management

system. This system is employed in batch processes, as well as

in the continuing processes.

The continuous monitoring and analysis of production data

(such as pH value, temperature, viscosity, solid contents, air

content, etc.) are an effective in helping to detect and locate

quality disturbances.

The GAW-quality management system allows the immediate

detection of changes within the process, before these can

cause any problems, such as reduction of quality, or runability

in subsequent process steps.

GAW-QUALITY MANAGEMENT

Quality loop

IMPRINT:Publisher: GAW Pildner-Steinburg GMBH Nfg & Co KG, Graz, Austria;

Creation/Conception: Biedermann & Jessenko; Photos: Toni Muhr, GAW-Archiv;

CAD-Graphics: GAW CAD-Department, ME 10 (2D-Prg.), Solid Designer (3D-Prg.);

Reproduction: Kufferath; Print: Dorrong

GAW Industrial ConstructionGAW Pildner-Steinburg GmbH Nfg & Co KG

Austria • Puchstraße 76 • 8020 GrazTel.: +43/316/27040 • Fax: +43/316/273266

e-mail: office@gaw.at • http://www.gaw.at