Sludge treatment – drying

GIOTTO WATER has technologies to best meet all drying requirements!

Thermal drying is a process for the reduction of the volume of wet solid products, by removing the water and achieving dry solids concentration over 90% DS. This process has proven applications in both the environmental field (volume reduction of sludge from wastewater treatment plants) as well as in production processes of industries, such as chemical, pharmaceutical, food processing and minerals processing. In thermal drying process, the final product is stabilized in a dry granular form that simplifies the storage, delivery, use or disposal.

Applications

Thermal drying of sludge allows to obtain a final product suitable for reuse in different applications depending on the composition of the treated product.

Sludges:

  • Municipal wastewater treatment
  • MSW Anaerobic digestion
  • Distilleries
  • Breweries
  • Slaughterhouses
  • Farms
  • Tanneries
  • Oil mills
  • Textile industries
  • Chemical/pharmaceutical

Other products:

  • Food industries (soybeans, yeasts, starches, etc.)
  • Pharmaceutical industry (mycelia, pectines, etc.)
  • Chemical industry (hydroxides, acrylic, emulsions, polypropylene, PVC, etc.)
  • Mining industry (coal, iron and copper, dust, carbonates, calcium sulphate, etc.)

Regardless of the design requirements (type of product to be dried, available energy, evaporation capacity, etc.), Giotto Water is able to offer the technological solution most suitable for every problem, adapting the project to the Customer needs.

  • CTD – Convective Thermal Dryer
  • ECOFLASH – Thin Layer Dryer
  • SBD – Sludge Belt Dryer

CTD – Convective Thermal “triple pass” drum dryer

The wet product is dried by a stream of hot air. The process is performed inside an enclosed rotating drum.

Water evaporation capacity ranges from 1.000 to 10.000 kg/h The drying air stream is heated by a heat generator.

The process is performed inside an enclosed rotating drum consisting of three coaxial cylinders.

There are no rotating parts inside the drum with no wearing problems.

The dried product has a homogeneous and granular shape and is recovered in the product/process air separation section.

Different plant configurations are available according to the specific project conditions:

  • Total recycling of the process air, heated in an air/air heat exchanger arranged in series with the heat generator
  • Heat recovery from cogeneration plants or other waste heat sources
  • Reduction of washing and condensation water needs, through recirculation and cooling with evaporative towers
  • Exhaust gas deodorization by thermal, biological or chemical treatment
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CTD

ECOFLASH – Thin Layer Dryer

A high speed rotor centrifuges the product on the internal hot wall of a stator, heated with diathermic oil or steam, which transfers the heat to the “thin layer” of sludge.

Water evaporation capacity ranges from 750 kg/h to 3.000 kg/h.

The product to be treated is introduced into a drying chamber, constituted by a jacketed stator heated with diathermic oil or steam.

Inside the stator, a cylindrical coaxial rotor with adjustable paddles operates at a peripherical speed of 30 m/s.

The product is centrifuged on the stator in a thin layer with a thickness of 5 mm, in contact with the hot wall.

The paddles mix and extract the dried product, while an air flow, in countercurrent, allows the extraction of water evaporated and cools the dried sludge simultaneously.

The limited amount of air has the only purpose of transporting the water evaporated during the drying process, while all necessary heat is provided by conduction through the wall of the stator.

The drying process is single passage, continuous without recycle.

The dried product is granular, and dust free.

The main advantages of this technology are:

  • Application with different types of inlet product (organic and inorganic)
  • Reduced energy consumption
  • Minimum air flowrate and low emissions
  • Minimum plant footprint
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ECOFLASH

SBD – Sludge Belt Dryer

Able to work with different energy sources and particularly suited to the reuse of waste heat at low temperature. It has extreme operational flexibility, also with products to be treated at variable characteristics, thanks to the possibility to adjust the belt speed and the process temperatures.

Water evaporation capacity ranges from 250 to 6.000 kg/h. The belt dryer is a convective dryer, where the water is evaporated by a stream of heated air, that goes in contact with the wet product during its transport on a belt.

The dryer is configured with two drying belts, which allow to obtain the correct contact time between sludge and hot air, making it extremely flexible in terms of flowrate and final dryness achievable.

An inlet distribution system is necessary to preform the dewatered sludge and distribute evenly over the width of the upper belt for further transport within the drying tunnel, where a ventilation system allows to distribute the heated air on the sludge in a uniform and constant manner.

The main advantages of this technology are:

  • Application with different types of inlet product (organic and inorganic)
  • Pelletized final product with no dust
  • Reduced energy consumption and the possibility of recovering heat from sources at low temperature
  • Low emissions
  • Low process temperature
  • Easy installation and reduced footprint
  • Modular construction
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SBD
Annunci

Sludge treatment – post dewatering

ATLANTIS

Belt press filter, at high operating pressure, specifically designed for post-dewatering.
The mechanical components are designed for a heavy duty, high demanding application, in order to ensure reliability and continuity of operation even in treatment of the most difficult products, such as industrial ones.

The unit is able to achieve an increment of 12 points, in percentage, of the dry matter content of the treated material.

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ATLANTIS

TSP

Twin screw press, designed for high rate dewatering treatment of fibrous materials, such as dewatering of primary paper mill sludge. The efficiency of the pressing system enables to reach a very high dry solid content, even with an high rate of throughput, while the operating costs are kept to a minimum.

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TSP

Sludge treatment – dewatering

The sludge (solid concentration 1-5% DS) is concentrated, to obtain a solid content in the range from 18 to 40% DS. As a result of dewatering, the product achieves a solid consistency that allows to handle and dispose it easily.

Giotto Water offers a wide range of dewatering machines, designed to meet the specific needs for both civil and industrial applications.

WR GREENLAND

Belt press filter, with an innovative design, to obtain the highest performances ever reached by a belt press filter. This result is achieved by increasing the working filtration area and the efficiency of the low pressure system (with wedging roll).

The mechanical components have been designed to guarantee reliability and continuity of operation, even in the more difficult operating conditions.

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WR GREENLAND

CMF OPTIMA

Belt press filter designed for dewatering both municipal and industrial sludges. The new modular frame concept combines outstanding performance with low capital costs, thus maximizing the costs/benefits ratio. It is suitable to treat sludges in a wide range of concentrations: the “Standard” version of the machine is designed to dewater sludges with standard solid concentration, while the “Cascade” version, in combination with a belt thickener, fits for very diluted sludges. The high pressure zone, modular, is available with 8 rollers: in option, it can be easily converted to an 11 rollers zone, adding a 3 rollers module to increase final dryness.

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CMF OPTIMA

MDC

Belt press filter for dewatering of biological sludges, municipal and industrial.

Compact enclosed design, including a high pressure zone with 6/8 rolls. Simple and cost-effective construction, with minimum space requirement and efficient operational results. Frame available in hot dip galvanized or stainless steel.

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MDC

C

Belt press filter designed for dewatering both primary and mixed fibrous sludges (pulp and paper industry, sugar beets mills, etc). It features a high pressure zone, with 7 “S” rolls of equal diameter, followed by a linear pressure NIP to further increase the final dryness up to more than 40% BDS with most fibrous sludge.

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C

SD

Belt press filter for mineral slurries, specifically designed to treat high flowrates at low feed concentrations. The large gravity zone and the long retention time in the low pressure zone, consisting of a large diameter perforated roll, enables the machine to effectively dewater sludges with very fine and unstable solids.

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SD

Sludge treatment – thickening

The very diluted sludge (solid concentration 0,5 – 1,5% DS) is concentrated to obtain a solids content variable from 6 to 8% DS. This operation reduces the sludge volume from 5 to 15 times. The consistency of the thickened sludge is still fluid or semi-fluid and usually requires further treatment. Giotto Water offers the rotating drum thickener – Rototik and the belt thickener – Gravity Table.

ROTOTIK

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ROTOTIK

Mechanical rotating sludge thickener, capable to thicken the sludge up to a concentration of 10%. The construction is entirely in stainless steel. The sludge is delivered to the external mixer to be conditioned with chemicals and then discharged inside the thickening drum. The drum consists of 4 zones separated by anular rings, each of which has an adjustable opening to adapt the sludge retention time according with its characteristics.

GRAVITY TABLE

Continuous sludge belt thickener, where the water drains through a moving polyester filtering belt, separating the solids contained in the sludge from the filtrate. The use of special plows improves the drainage by alternately compressing, reversing and distributing the sludge on the belt. Even the most unstable sludge can be easily treated with this unit. The Gravity Table separates fast over 95% of the suspended solids from the sewage sludge, with a minimum consumption of polyelectrolyte.

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GRAVITY TABLE

Tertiary treatments – water reuse

Final filtration or tertiary treatments are more and more required, in consideration of the more demanding regulation for water effluent quality, in relation to suspended solids. Final filtration systems also allow water reuse, both in industrial or agricultural application. Giotto Water offers the disc filter and sand filter, according to the required suspended solids content in the effluent.

DISC FILTER NDF / SDF *

The machine consists of one or more filtering discs, fixed on a robust central drum. The waste water flows through the central drum and then is transferred into the center of each media panel. A quick and efficient backwashing system starts automatically once the prefixed level of water is reached. The modular design as well as the possibility to use different kinds of filtering elements (stainless steel or polyester), allow to satisfy the highest filtration requirements.

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NDF/SDF

*  under license of Evoqua

Filtering panels

The panels are available in three kind of filter cloths, according to the specific needs of the requested application:

filtro-1
Patent flat panel in Aisi 316L with higher performances in terms of treated flow and strength
filtro-2
Patent flat panel made of polyester
filtro-3
Patent “pleated” panel with polyester mesh that provide 40% more surface area at equal number of discs

Each disc can be easily replaced in a matter of seconds, simply by loosening the locking screws. The panels can be easily and fast removed with no need of emptying the tank or disassemble the filter.

SAND FILTER – ASF

Sand filters, with a bed of sand – or sand and anthracite – operating by gravity without the need of backwashing pumps, thanks to an automatic system activated by siphons. Available in single bed or in two beds design, one placed on top of the other, operating in parallel, which allows to double the flowrate treated in the same space. It is also available in the “Combi” version, with the two beds operating in series: the upper sand bed for the removal of suspended solids and the lower one, with activated carbon, for reduction of the residual BOD.

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ASF

Waste water treatment

Primary Treatment

The first treatments, useful to remove solids from wastewater, include screening (coarse and fine) and sedimentation sections. In the first step, there is the solids removal, that could cause clogging of pipes and pumps; in the second step, there is the separation of settling solids by gravity. Giotto Water offers rotating drum screens and disc screens.

FINE SCREENING – ROTODRUM

Fine screen, with rotating wedge-wire drum. The water is tangentially introduced into the screen, through a special distribution headbox. Solids are captured inside the cylinder, thickened and continuously discharged to the outlet, while the filtrate flows through the opening of the wedge-wire. The Rotodrum is completely manufactured in stainless steel.

The screen openings range from 0,5 to 5 millimeters.

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ROTODRUM

FINE SCREENING – DISCOSCREEN

Microscreen with rotating discs. The filtration unit consists of a screen cloth supported by discs. The water flows through pairs of discs (from 1 to 6 pairs): while the filtrate passes through the screen cloth, solids are continuously removed, thickened and discharged. The screen cloth and the structure are made in stainless steel.

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DISCOSCREEN

Biological treatments

These processes allow to remove the biodegradable organic substances (suspended and soluble) from the wastewater, and to transform them into settling solids, treatable in the “sludge line”.

Giotto Water offers biodisc.

BIODISC (RBC)

RBC or Biodisc is a simple and reliable unit for reducing the BOD by biodegradation, and for nitrifying civil and industrial waste.

They provide high efficiency performance in eliminating the polluting matters, for carbon removal and nitrification/denitrification processes. The use of biodiscs offers a remarkable saving of space, minimizing the environmental impact and simplifying plant management. Energy consumption is drastically reduced when compared to traditional processes.

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BIODISCHI

Primary water treatment

Primary water treatment

The need to have an adequate quality of water is fundamental in civil field, where it is used for drinking, cooking, washing and for the individual and collective hygiene, but also in the industrial field.

On the other hand, the water we need every day can have various origins (surface water or ground water) and may contain, in addition to its natural components, also variable amounts of organic and inorganic material, depending on the type of soil and on the presence of residential areas, industrial and agricultural activities.

For its possible use, it must therefore be treated using physical methods and/or chemical-physical ones, according to the characteristics of the starting raw water and the specific use that the treated water will have.

Giotto Water offers the disc filter.

DISC FILTER NDF/SDF *

The machine consists of one or more filtering discs, fixed on a robust central drum. The waste water flows through the central drum and then is transferred into the center of each media panel. A quick and efficient backwashing system starts automatically once the prefixed level of water is reached. The modular design as well as the possibility to use different kinds of filtering elements (stainless steel or polyester), allow to satisfy the highest filtration requirements.

*  under license of Evoqua

Filtering panels

The panels are available in three kind of filter cloths, according to the specific needs of the requested application:

filtro-1
Patent flat panel in Aisi 316L with higher performances in terms of treated flow and strength
filtro-2
Patent flat panel made of polyester
filtro-3
Patent “pleated” panel with polyester mesh that provide 40% more surface area at equal number of discs

Each disc can be easily replaced in a matter of seconds, simply by loosening the locking screws. The panels can be easily and fast removed with no need of emptying the tank or disassemble the filter.