Waste water treatment with activated carbon

Problem:

Activated Carbon is used to absorb the reactive components in waste water.
Depending on the application, activated carbon may be dosed continuously from a BigBag, a silo or directly from bags.

ystral processing technology:
Dosing of Activated Carbon with the ystral Conti-TDS may be set-up as a fully automatic system.
The Activated Carbon is inducted directly from a BigBag.
Alternatively activated carbon suspensions may be produced with the ystral Conti-TDS or ystral Jetstream Induction Mixer by inducting a given amount of Activated Carbon into a given quantity of liquid in a suspension vessel.
For extreme situations (such as dangerous spillage) the ystral Conti-TDS on casters has proved to be very useful.
The machine is equipped with a switchboard and automatic valves.
In an emergency it is brought directly to the location and inducts the Activated Carbon from a bag.
The Activated Carbon is completely wetted and there is no dry powder floating on top of the liquid.

Advantages:

• Dust- and loss-free operation
• Complete wetting
• Optimum dispersion of powder ensures maximum efficiency of the activated carbon
   

Direct neutralisation of waste water

Problem:

Hydrated lime, limestone powder and fine white limestone is used for direct neutralisation of waste water.
Dosing of the required quantity of limestone is controlled by the pH-level of the waste water.
The pH-level varies continuously and has to be controlled by a suitable control circuit.

ystral processing technology:

With the ystral Conti-TDS the limestone can be inducted Inline into the water stream.
The ystral Conti-TDS continuously inducts air into the waste water and this air stream is used to induct the limestone.
The dosing rate is controlled by the pH-level.
The limestone is completely wetted and comes into the waste water as a suspension.

Alternatively a suspension in a vessel with a constant concentration may be produced with the ystral Conti-TDS.
This suspension is introduced into the waste water with the dosing rate again controlled by the pH-level.
Basically both applications are possible.
As it is much easier to control the liquid suspension, this application can be realised with much less effort.

Advantages:

• Dust- and loss-free operation
• Complete wetting
• Desagglomeration of the powder during wetting
• Automatic operation

PVC coating for mesh wire

Problem:

Different fillers such as oxides, silicates, sulphates and carbonates are inducted into a plasticiser and have to be wetted and dispersed.
The concentration of solids usually is very high, which means a large amount of powder has to be treated during the production.
If harmful powders - such as lead pigments - are treated, then production has to be carried out with all necessary measures for personal safety.

ystral processing technology:

For this application an ystral Conti-TDS-3 is used.
It is connected to different vessels and inducts the powder dust-free, wets it and then disperses it down to the required particle size.
When inducting pyrogene Silicic acids, such as Cab-O-Sil, Aerosil etc., a much higher degree of wetting and better composition of the powder is achieved compared to conventional wetting processes where the powder is brought into the liquid manually.
The result is a higher viscosity for the same concentration.
The processing time is reduced considerably.
Optimum wetting, and the additional benefit of dispersing with the same machine, reduces the grinding and dispersing time for this product.

Coatings for seeds

Problem:

During the production of coatings for seeds, powdery fillers, additives, pigments and binders have to be inducted into a liquid.
The consistency and components of the coatings vary from producer to producer.
The basic application is to induct the powder, completely wet and disperse it and distribute it homogeneously into the liquid.
Several processing steps are required when using conventional processing.

ystral processing technology:

When using an ystral Conti-TDS the powdery substances are immediately wetted, completely des-agglomerated, dispersed and distributed homogeneously.
Depending on the foaming tendency, it is necessary to induct the powder without any excess air.
In this case the powder is not inducted with the vacuum hose but from a container, funnel or similar.

Advantages:

• Complete and dust-free wetting and dispersing
• No loss of additives
• Higher efficiency of the powders used (higher viscosity at the same concentration)
• Closed processing vessel - the operator is not exposed to dust and gases
• Reducing the processing steps means less equipment and saving of time

Underseal coating, heat insulation mass, noise reduction mass

Problem:

These products are characterised by a high content of special fillers and a special flow characteristics.
When using the product, it has to stick to the treated surface and retain a certain thickness.
Any material above this thickness has to flow away.
Therefore these products must show a highly thixotropic behaviour, independent of the high concentration of solid material.
The powders involved show a different reaction depending on the degree of wetting and dispersing - the more they are dispersed, the better their efficiency.

ystral processing technology:

With the ystral Conti-TDS, the fillers, as well as the thixotropic agents, are inducted into the liquid absolutely dust-free, wetted and then dispersed.
These products show a very low viscosity when treated with a rotor/stator system.
As the ystral Conti-TDS is a machine with a very high peripheral speed, all the above products can be treated very easily.
The process is dust- and loss-free.
The different powders are inducted with the induction tube directly from bags.

Because of the extreme thixotropic reaction, these products offer an ideal application for the ystral Conti-TDS technique.
As the degree of dispersing and wetting is independent from the operator, and carried out at a constant rate, the quality of the product will be constant as well.
The machine can be integrated into an existing plant very easily.

Conversion of distillation residues

Problem:

Residues of distillation processes - e.g.. vitamin synthesis - contain a lot of different products.
These can be tar or silicate lumps.
These residues are mechanically reduce in size and then mixed with solvents and incinerated.
To avoid sedimentation of the suspension during transportation, it is mixed with highly dispersed, pyrogene Silicic acids - e.g. Aerosil or Cab-O-Sil - to achieve a thixotropic behaviour.

ystral processing technology:

The silicic acid is inducted directly into the solution with an ystral Conti-TDS.
The machine is connected to the existing vessel containing the suspension.

Advantages:

• Dust-free operation
• No floating of Aerosil on the surface of the liquid
• No dust comes out of the liquid
• Higher viscosity with the same concentration of silicic acid, optimum wetting and better breaking-down of the powder
• Better stability of the suspension during transportation

Disposal of dioxin-contaminated powders and gases

Problem:

Conventional disposal of dioxin-containing powders - e.g. disposal companies or foundries - costs several hundred thousand pounds every year.

ystral processing technology:

On the basis of an ystral Conti-TDS, a process was developed to completely recycle the filter dust and the gas with a chemical procedure. After the chemical procedure, the remains do not have to be disposed of as special waste.

Advantages:

The vacuum created in the ystral Conti-TDS inducts the powder, dust and gases completely, without any residues, into the liquid. Additional filter systems, vacuum pumps or similar that create dust and gases themselves are not required.

• Complete wetting during the induction
• Because of the induction no potential risk for leakage in the induction pipe.
  In this case only air will be inducted and no gases or dust can come out of the system.
• Very short amortisation since no special waste is produced
• Closed process
• The operator is not exposed to dust or gas

Production of fibres

Problem:

In Polyamid, Polyester or viscose fibres, large quantities of Titanium Dioxide are used.
The purpose of the Titanium Dioxide pigment is to structure the surface of the fibres in such a way that they do not stick together (anti-blocking).
It also influences the colour, light stability and mechanical property of the fibres.
High-quality fibres require optimum wetting and dispersing of the Titanium Dioxide.
The required degree of finesse is so high that a standard particle size analysis is not sufficient for quality control - filter tests are necessary.
Until now it was usual to wet the Titanium Dioxide, grind it and then pass a centrifuge.

ystral processing technology:

With the ystral Conti-TDS the wetting and dispersing process is realised in one machine.
The Titanium Dioxide is inducted directly from a BigBag, immediately wetted and then dispersed down to the required particle size.
Together with a leading German manufacturer of Titanium Dioxide, tests were run and the product analysed in their laboratories.
The result is:

• The required particle size (filter test) is reached
• The surface of the particles is less damaged compared to conventional grinding methods
• The induction is absolutely dust-free
• As the induction speed is very high, a big advantage is achieved compared to the conventional processing technology

The ystral Conti-TDS is used world-wide for this application.
The machine is recommended by leading manufacturers of TiO₂ for the production of fibres.

Foils / Films

Problem:

Titanium Dioxide is used for the production of foils and films.
The purpose of the Titanium Dioxide is to influence the surface of the material in such a way that the foils do not stick together when rolled up (anti blocking). It also has an influence on the optical and mechanical properties of the films and foils.
Depending on the application, a very high degree of dispersion has to be reached for the Titanium Dioxide.
In conventional processing, Titanium Dioxide is manually poured into the liquid from bags and then dispersed.
The dispersed suspension additionally has to undergo a grinding process.

ystral processing technology:

With the use of an ystral Conti-TDS it is possible to induct the powder dust-free from a bag directly into the liquid. The moment it comes in contact with the liquid, it is wetted and immediately dispersed.
After the induction, the suspension is dispersed Inline to reach the required particle size.
The ystral Conti-TDS can be integrated into any existing system without any problem

Herbicide, insecticide, plant protection

Problem:

Active substances, fillers and powdery binders have to be brought into a liquid absolutely dust-free.
The active ingredients, for safety reasons, are not allowed to escape into the surroundings.
Conventional methods require a complicated technical standard to achieve this result.
Powder transportation, wetting, dissolving and dispersing are carried out in several different processing steps.
The filter dust and the filters in the exhaust system have to be disposed of as special waste.

ystral processing technology:

With the ystral Conti-TDS all these powdery substances may be inducted into a liquid absolutely dust- and loss-free, they are completely wetted and dispersed.
When inducting from barrels or powder drums, this process may be carried out absolutely dust-free.
When inducting from bags with the induction hose and pipe, please note that the handling and opening of the bags, as well as their disposal, has to be carried out dust-free.

Advantages:

• No powder comes out of the surface of the liquid when using the ystral Conti-TDS
• No crusts on the wall of the vessel or the stirring shaft
• Complete wetting and dispersing
• The machine may be integrated into existing systems
• As the vacuum is created by the machine itself, no vacuum vessel or additional vacuum pumps are required.
• In case of a leakage in the induction line, only air is inducted, no dust will leave the system

Filler for fibres in PVC

Problem:

Fillers in the production of PVC are mainly used to reinforce the product.
For this task different organic and inorganic fibres are used.
Normally not only fibres are used, but powdery fillers and pigments as well.
Another field of use for fibres is the production of resin.
In this application the fibres are added to the liquid resin as a filtering aid prior to filtration.

ystral processing technology:

Short types of fibres (glass fibres, cellulose fibres up to 600 µm) may be treated with the ystral Conti-TDS without any problem.
They can be inducted with vacuum, which is created by the machine, into the liquid.
The induction pipe to be used with these powders has to be selected by a test.
In the ystral Conti-TDS the fibres are completely wetted and dispersed.
As the flow characteristics of the un-wetted fibres as well as of the suspension varies, a test in our pilot plant or on site is strongly recommended.

Advantages:

• Dust- and loss-free operation
• Complete wetting and dispersing in the machine
• Easy integration into existing systems

Resin lacquers, laminating resin, gel coats, grout

Problem:

High disperse pyrogene Silicic acids are inducted into unsaturated polyester resin as a thixotropic agent.
Depending on the application (laminating, coating, filling ...) different concentrations of Silicic acid are brought into the liquid.
Very often the Silicic acid is treated in open vessels.
The powder is manually poured into the dissolver vessel causing unwanted dust.
The wall of the vessel and the shaft of the mixing element are covered with partially wetted crusts.
This type of wetting is not economical.

To reduce the amount of dust, special transportation facilities are installed.
They induct the powder and then transport it into a closed mixing vessel.
This causes the same amount of air being brought into the vessel which has to be exhausted together with the vapour of the solvent through filter systems.
As the specific weight of the high disperse Silicic acid is very low the amount of dust is very large.

The problem with the crusts on the wall of the vessel and shaft of mixing element is not solved.
Wetting and dispersing needs a lot of time as the light powder floats extremely long on top of the liquid surface.
Exhaust systems are required.
These filters must be able to filter out the vapour of the solvent and the dust, a very expensive solution.
The considerable loss of powder in these filter systems is very difficult to calculate.

ystral processing technology:

The powder is inducted into the liquid absolutely dust- and loss-free, completely wetted and dispersed.
Three different types of machines may be used:

• ystral TDS-Induction Mixer for dust-free induction into the liquid and intensive mixing of the Silicic acid solution in the vessel at the same time
• ystral TDS-Dispermix, with additional dispersing effect
• ystral Conti-TDS as an Inline machine to be installed outside of the vessel. All the energy is brought into the product as dispersing and wetting energy.

During the use of the ystral Conti-TDS additional and very interesting effects were observed:

• The viscosity of a Silicic acid suspension, produced with an ystral Conti-TDS is always higher compared to that produced with conventional methods.
• The reason for this is the better breakdown of the powder.
• Unsaturated polyester resins contain solvents.
  The atmosphere above the liquid is mixed with volatile solvents.
  When the high disperse Silicic acid is poured into this atmosphere it combines with the gas because of its affinity to the solvent.
  This part of the Silicic acid changes its property and has no further part in the wanted structure of the viscosity.

This means, with the conventional process more powder has to be added than is really needed. When producing resin paints, this is a major disadvantage. The less powder that is brought into the resin, the less is the delustreing (matting) effect of the product.

The powders are expensive as well.

With the ystral TDS-principle the wetting is carried out under vacuum.
The powder is inducted directly into the liquid and is immediately wetted and dispersed.
This causes a much higher efficiency of the powders and a higher degree of dispersion is achieved with the ystral Conti-TDS compared to conventional methods.
The ystral TDS-principle meanwhile is used world-wide for the induction of Silicic acid into resin.

Advantages:

• Higher quality compared to conventional methods
• Dust- and loss-free operation
• No partially wetted crusts and lumps on the wall of the vessel and shaft of mixing element
• Powder does not have to be brought into the solvent-containing atmosphere by the operator
• Flexible batch sizes short time for amortisation