Detergent

The TKS for the production of detergent powder is unrivalled, as proven by more than 550 plants installed under Ballestra’s proprietary design and know-how all over the world as since 1960.

As a matter of fact, the Desmet Ballestra plants are estimated to cover significative part of the world's production of synthetic powder detergents.

A permanent and qualified research staff is dedicated to improve the technology by optimizing the existing processes and developing new ones in the laboratories and pilot plants installed at our Milan headquarters.

The close collaboration with researchers and scientists of University boards, environmental organizations, Scientific Committees, multinational companies, etc. as well as the exchange of information at the main international congresses and seminars on detergency, which Desmet Ballestra is attending with reports and papers, have contributed to increase the significant technological knowledge of our Company enabling it to meet the specific requirements of the worldwide manufacturers of detergent products.

The extensive experience and know-how in detergent plants operation also allows Desmet Ballestra to assist Clients to better define their requirements in terms of production programs, training of operators, raw material purchasing, product formulation and packaging etc. so contributing to the best success of new projects.

New raw materials coming on the market are carefully studied and tested, to define the best plant operating conditions in terms of product formulation and process optimization.

The physico-chemical characteristics of detergent powders to be produced are studied to identify the optimum product characteristics in order to meet local washing habits and specific market requirements.

Great importance is given to environmental pollution control. Each plant designed by Desmet Ballestra is conceived to avoid liquid effluents, while the exhaust gases are treated to comply with the most stringent international specifications, thus allowing the installation of plants even close to urban areas.

Special care is given to energy saving and to reduce the overall fuel and electric power requirements.For large plants capacities, whenever required by local conditions, Desmet Ballestra has also studied and implemented co-generation systems based on the use of gas turbines to produce electric power, and on the use of relevant hot exhaust gases in the spray tower to substantially increase the overall plant efficiency.

The great flexibility of Desmet Ballestra plants, together with the flexibility of processing different raw materials and producing a wide range of formulations, make Desmet Ballestra spray drying plants able to meet even the most sophisticated market requirements.

Plants standard capacities range from 1000 to 30.000 Kg/h. Each plant is designed taking into account the possibility of substantial future increase of production capacity with limited investment cost.

Spray Drying Tower process

Spray-drying plant for the production of detergent powders of low and medium density, covering the full range of commercial formulations including a post addition of thermosensible components, up to powder packaging.

The slurry is pumped to a spray nozzles circuit installed in the upper part of the spray tower.

The size and number of nozzles depends on the plant capacity and required product granulometry.

The spray is generally of the hollow cone type and nozzle size generally varies in diameter from 3 to 5 mm with a spray angle in a range of 50-70°.

In the spray tower the special design of the hot air distribution chamber allows operation with high differential temperatures i.e.: hot air inlet temperature up to 400-450°C, exhaust air outlet temperature down to 85-90°C with consequent optimum thermal efficiency.

The optimization of the design of hot-air inlet ducts and the design and positioning of slurry distribution nozzles result in overall improvement of the drying path through the Spray-Tower.

This fact, together with the increase of solid matter content in the slurry and the increase of hot-air temperature, results in increased evaporation efficiency of the Spray-Tower.

All the operating conditions are automatically adjusted by setting the proper parameters of fuel feeding, air flow, slurry concentration and all pressures/temperatures at the required optimum value, for controlled heat and mass balance of the process.

The characteristics of the powder beads are largely determined by direction, velocity and temperature of the hot air stream.

The hot air is generated in furnaces purposely designed to obtain smokeless combustion.

The most commonly available fuels (ranging from natural gas to heavy fuel oils), can be utilized without causing inconveniences nor affecting the whiteness of the finished products.

The hot air is conveyed to the lower part of the spraying tower. Two fans, determining the pressure conditions of the air circuit, are installed for regulation of the air-flow passing through the tower. By means of this circuit the hot air is conveyed via a special distribution ring located at the bottom and from there up to the top of the tower coming into contact countercurrently with the slurry spray falling down from the top.

sabiz2The detergent powder with bulk density in the range of 200-450 g/l, is discharged from the tower at a temperature of 60-70°C and is transferred by means of a belt, to a continuous crystallization unit (air-lift), where it is conveyed upward by a flow of ambient air that cools it down so completing the drying and initiating the particles surface crystallization.

By this way the product is also lifted up to such a height as to allow the next operations by a gentle gravity-discharge avoiding as much as possible any breaking of the hollow beads.

Both the drying and transport air are sucked through sleeve filters before being discharged to the atmosphere.

The separated fines are reblown into the spray tower, close to the slurry spraying zone, so as to fully recover them by agglomeration with the slurry droplets.

The detergent powder finally collected in the air-lift bottom cone are discharged into a sieve to remove any coarse agglomerated/wet material before eventual post addition, perfuming and packaging. The coarse material from the sieve is reprocessed via a separate dry or wet mixing/milling directly into the slurry preparation step.

The base powder obtained by the steps of spray-drying and subsequent product conditioning doesn’t contain those components that, due to their chemical characteristics, are sensitive to increased temperatures and consequently have to be incorporated into the powder recipe in a way that preserves their chemical and physical structure.

The step of Post-Addition of these components is performed in a special Rotary Blender where the base powder and the thermosensitive component (both solids and liquids), are gently and intimately mixed and agglomerated, so resulting in a final product having characteristics of regular shape, high flowability and chemical stability / homogeneity. The configuration of the post-addition unit can be very different according to the specific requirements of the final powder formulation and plant capacity.

For high production rates a continuous unit is recommended, which can be configured similarly to what is foreseen for the COMBEX section (Spray-Drying plus Agglomeration)

SABIZ process control

sabiz1The SABIZ plant is operated by a Computer Control System “CCS” specifically designed for reliable and performing operations with an easy to use and friendly operator interface.

The computer control system ensures a trouble free plant operation with the automatic control of all the critical process parameters. It also guarantees a high dosing accuracy and therefore the accuracy and consistency of the product formulations. Moreover, the computer control system reduces to a minimum labour requirements for plant operation.

Up to 100 different preset formulations can be stored in the computer memory and the system automatically adjusts all process parameters and dosing devices to achieve the final formulation selected by the operator.

The CCS is built using the most advanced architecture that includes a PLC for process and production data control. The PLC is foreseen for digital and analog signals handling and it is provided with one or more CPU, designed to make all controls (PID loops, data acquisition, alarming, interlocks, sequences, etc.) by programmable logic.

The supervisory system based on PC establishes a “friendly interface” with the operator, through an animated process video screen-layout, diagrams, trends, list of process variable figures, operators entry windows, etc.

The PC will run the Windows NT Workstation operating system and Logoview NT HMI/SCADA package.

NTD (Non Tower/Agglomeration) process

A Non Tower Detergent powders production plant based on proprietary agglomeration technology, also based on the special Kettemix reactor, for the production of medium-high density detergent powders

The NTD Non Tower Detergent production technology, based on the KETTEMIX reactor/granu-lator, has been developed by Desmet Ballestra to meet the worldwide market requirements for detergent powder production with reduced energy demand and manufacturing costs, without limitation to the physical, chemical and performance characteristics of the products.

DesmetBallestra’s know-how for the manufacture of high quality detergent powder and its unique expertise achieved with the supply of more than 550 spray drying plants all over the world have merged into the design of this reliable, easy to operate NTD plant.

The Desmet Ballestra NTD process is based on the principle of agglomeration between solid and liquid components.

The process includes the following steps:

  • Solid and liquid raw materials handling and dosing
  • Dry neutralization and agglomeration in the Kettemix reactor
  • Product drying/cooling in fluidized bed conditioner
  • Post addition of thermo-sensitive components
  • Detergent powder sieving, perfuming and distribution to packaging

The process equipment can be sized for production capacities from 2 to 20 t/h of detergent powder.

In case of a plant capacity over 5 t/h, the dosing of solid components can be performed by a fully automatic continuous dosing system, while for lower capacities, a blend of solid components is continuously dosed to the process after a batch type pre-mixing.

Benefits and Advantages
  • Limited Investment costs
    • High production flexibility in terms of powder formulation and physical characteristics, namely:
    • total active matter content: up to 25%
    • powder bulk density: 500 to 1,000 gr/lt (by using particular components)
    • Low energy consumption
    • Ease of operation with limited manpower requirementsLow installation costs
    • limited building requirements (the plant is designed for housing under shed over a concrete floor)
  • Negligible environmental impact
  • No gaseous nor aqueous effluents

The liquid form for household detergents is gaining market share in many world markets particularly for dish washing and light-duty applications. Moreover, the personal care products in liquid form have a substantial share of the market and can be manufactured in the same plants as liquid detergents.

For this reason, whenever reference is made here in after to liquid detergents, it is meant to refer also to personal care products.

Independently on the type of liquid detergents or personal care products and their specific targeted uses, the manufacturing of liquid detergents should be based on processes, equipment and operation sequences in compliance with the chemical and physical demands of these products.

The formulated liquid detergent, where the various components have to be "incorporated", has to be stable. This target is accomplished when all the formulation components are properly selected and their introduction into the product recipe is such as to avoid a strong variation to temperature, pH and viscosity, as well as undesired chemical reactions.

In other words, the manufacturing of liquid detergents requires high care in constituting stable and strong “micelles” distributed into the liquid product. This is commonly perceived as "product homogeneity".

What is required for a liquid detergent, independent of its task and specific application, can be summarised as follows:

  • Outstanding global performance
  • Nice appearance (colour and degree of transparency)
  • Controlled viscosity
  • Stability vs. storage time, temperature and light effects

The manufacturing of liquid detergents should be based on a good knowledge of the chemistry and rheology of the detergent components and the capability to control and to modify their interactions. Suitable and appealing packaging is also of great importance.The manufacturing of all types of liquid detergents involves the steps indicated in this scheme:

The production of liquid detergents requires processing equipment capable to cope with the following demands:

  • Possibility to process fluids in a wide range of viscosity (up to 5-6000 mPa.sec)
  • Possibility to use alcoholic solvents (necessity of explosion-proof design)
  • Easy coupling with a Computerised Process Control System
  • High resistance and corrosion-proof construction materials (stainless steel and special alloys)
  • Capability to provide high heat-transfer rate (for both cooling and heating)
  • Capability to provide intimate and constant mixing
  • Possibility to correct pH, viscosity and temperature (by specific devices)
  • Possibility of fast and simple cleaning (to reduce product change-over time) without risk of contamination

Ballestra has developed the LIDET Technology for the production of Liquid Detergents, offering a wide range of plant capacities and the choice of two different process routes (Batch or Continuous), in order to cope with the specific client production requirements.

Regardless of the type of process route, the Ballestra LIDET Plants allow the production of Liquid Detergents whose application properties and physical characteristics are summarised here below: