LIME SILO
INTEGRATED SOLUTIONS FOR LIME DOSING
At FDWATER, we offer complete, modular systems for lime dosing and slurry preparation, tailored to each client’s specific process and needs. Our solutions enable precise control of the dosing flow rate and high operational availability, resulting in efficiency, safety, and service quality.
Whether for pH adjustment, remineralization, sludge stabilization, or gas treatment, we design and integrate robust and versatile equipment that meets the requirements of every installation.
Available equipment
It prevents the formation of arches and ensures continuous dosing of the powder or microgranulated product.
Capacities from 10 m³ to 200 m³. Equipped with extraction, weighing, level measurement and remote control systems. C3/C5 options for outdoor use.
Designed for the safe and clean unloading of 500 to 1500 kg bags. Equipment with integrated extraction and dosing system.
Compact solution for dosing lime from 25 kg bags. Ideal for moderate consumption or pilot installations.
Automatic equipment for preparing grout with different concentrations (e.g., 5%-10%). Integration of agitation systems, level control, automatic cleaning, and pumping. Fixed or variable concentration.
Advantages of our solutions
High dosing accuracy
Easy maintenance and accessible components
24/7 operation capability
Integration with customer control systems
ATEX options and materials for corrosive environments
Catalogue
Vault breaker + Screw dispenser
DBS System – Precise Dosing for Powdered Products
The FDWATER DBS model is an advanced solution for the controlled discharge and dosing of powdered products directly from storage silos. Its compact design and purely mechanical operation make it an ideal system for industrial installations requiring high reliability, precision and low maintenance, even under demanding operating conditions.
This equipment is especially suitable for installation under silos with conical bottoms (60°) and offers a wide operating range: from micro-dosing up to flow rates exceeding 15,000 L/h, depending on the nature of the product.
Integrated Decompaction and Dosing Technology
At the core of the system is a vertical turbine with flexible blades, whose function is to decompact the stored material and prevent blockages or the formation of bridges during discharge. This rotary movement promotes a continuous and stable flow of material towards an intermediate hopper, eliminating typical caking problems.
From this hopper, a feeder ensures uniform feeding of the product into a dosing screw. The overall design guarantees that the screw always operates under saturated conditions, thus providing constant and reliable volumetric dosing, independently of the product level inside the silo.
Why choose the DBS system
- Constant volumetric dosing, without the need for fluidization or vibrating systems.
- Prevents moisture and compaction by eliminating the use of air.
- Fast installation with standardized connections and adjustable dosing screw.
- Adaptable to each project: available in rigid or flexible screw versions, with customizable lengths.
- Multiple dosing units can operate from a single silo.
- Low energy consumption and minimal mechanical maintenance.
- Compact footprint, ideal for retrofits or plant expansions.
Applications
Sectors
This system is especially effective in sectors such as:
• Water and gas treatment
• Feeding of kilns and reactors
• Chemical and environmental processes
• Solid powder mixing processes
• General industry
Technical Data Sheet
Lime storage silo
Storage, dosing, slurry preparation and pumping
FDWATER designs and supplies complete systems for lime handling, from storage in silos to precise dosing and automatic preparation of calcium hydroxide (Ca(OH)₂) slurry, ensuring a continuous, reliable process tailored to each customer’s requirements.
Thanks to our in-house manufacturing facilities and more than 30 years of experience in bulk solids handling, we provide robust and automated solutions, including all necessary equipment from product reception to final injection into the process.
Main System Components
- Fully equipped lime silo, with standard storage capacities from 5 to 200 m³.
- Mechanical extraction system with arch breaker, designed to prevent bridging and material compaction.
- High-precision dosing screw or volumetric feeding system, with automatic control.
- Isolation valve to avoid moisture ingress and prevent clogging.
- Automatic lime slurry preparation tank, with control of concentration, volume and dust emissions.
- Pumping system selected according to the specific application, with optional automatic cleaning.
- Electrical control panel with full process automation.
- Optional Big Bag feeding system for installations without bulk material logistics.
Applications
Drinking Water Treatment (DWTP)
- pH adjustment and correction.
- Remineralisation of demineralised or desalinated water (desalination plants).
Wastewater Treatment (WWTP / IWWTP)
- Neutralisation of acidic effluents.
- Precipitation of heavy metals, phosphates and fluorides.
- Sludge stabilisation, dewatering, and reduction of odours and pathogens.
Industrial Gas Treatment
- Neutralisation of acidic emissions (SO₂, HCl, HF).
- Dry or semi-dry flue gas treatment processes in incineration plants, cement plants and power plants.
Sectors
This system is especially effective in sectors such as:
- Water and gas treatment.
- Furnace and reactor feeding.
- Chemical and environmental processes.
- Solid powder blending and manufacturing.
- General industry.
Technical Data Sheet
Big Bag Unloader
Safe and Efficient Dosing of Powdered Products
FDWATER designs and manufactures complete systems for Big Bag unloading and dosing, specifically developed for powdered products such as calcium hydroxide (Ca(OH)₂) and powdered activated carbon (PAC). These systems are ideal for installations without bulk pneumatic unloading or where a more flexible, compact and cost-effective solution is required.
System Overview
The unloader consists of two main modules:
- Discharge module
Enables controlled and continuous unloading of the Big Bag contents into an intermediate hopper, ensuring tightness and preventing dust emissions. - Dosing arch breaker unit
Maintains a homogeneous product flow from the hopper to the dosing system (typically a screw feeder), ensuring accuracy and continuous operation.
Operating Principle
The process starts with positioning the Big Bag using a forklift or hoist. The bag is secured to the upper crossbeam and placed on a support frame with a vibrating table. This table ensures system tightness during discharge, eliminating the risk of dust emissions.
As the product is discharged, a constant-tension system keeps the bag extended to ensure complete emptying. From the hopper, the arch breaker provides a uniform flow to the screw feeder, which doses the product with high precision.
The system includes a level detector in the hopper, which automatically activates the vibrator when a low level is detected, ensuring continuous and uninterrupted operation.
Technical Features
- Compatibility: Adaptable to multiple Big Bag sizes and formats.
- Dosing capacity: From 1 litre/hour up to 8 m³/hour.
- Emission control: Fully enclosed system that eliminates dust dispersion.
- Direct operation: Allows dosing without the need to pre-empty the bag.
- Modular configuration: Optional with double independent dosing systems.
- Efficient emptying: Vibrating system and constant tension ensure complete discharge.
FDWATER Design Advantages
- Compact and modular design, ideal for limited spaces.
- Safe and clean operation, suitable for demanding industrial environments.
- Continuous operation, without stoppages or blockages thanks to the integrated arch breaker.
- Wide range of optional accessories to customise the equipment according to the product or process.
The FDWATER Big Bag unloader is a complete technical solution for the safe, precise and emission-free handling of powdered materials. Its modular and robust design makes it an ideal solution for any plant requiring reliability, versatility and efficiency in bulk material dosing.
Applications
Sectors
This system is especially effective in sectors such as:
- Water and gas treatment.
- Furnace and reactor feeding.
- Chemical and environmental processes.
- Solid powder blending and manufacturing.
- General industry.
Technical Data Sheet
Dosing hopper
Precise Dosing from Bags for Powdered Products
FDWATER designs and integrates dosing systems with manual loading hoppers, specifically developed for installations where powdered products—such as calcium hydroxide (Ca(OH)₂), powdered activated carbon (PAC) or other additives—are supplied in 25 kg bags. This solution is ideal for plants requiring controlled, reliable and compact dosing, without the need for silos or bulk unloading systems.
System Overview
The system consists of a receiving hopper with a top loading inlet and a volumetric arch breaker–doser that ensures a constant and controlled flow to the conveying or preparation stage.
- Manual loading hopper
Manufactured in carbon steel or stainless steel, it includes a safety grid, top cover and inspection opening. The truncated conical design with a 60° slope allows optimal product flow towards the dosing system. - Arch breaker–dosing unit
Equipped with a paddle-based extraction system, it enables uniform dosing even for products with poor flowability. The system prevents the formation of arches or product bridging, maintaining continuous and blockage-free flow.
Operating Principle
The operator manually pours the contents of the bags onto the upper grid of the hopper. From there, the product falls by gravity into the lower chamber, where the arch breaker system is activated, decompacting and extracting the product in a controlled manner. This system directly feeds a dosing screw, a slurry preparation tank or a pneumatic conveying line, depending on the plant configuration.
Technical Features
- Dosing capacity: From a few litres per hour up to more than 15,000 L/h, depending on the product.
- Compact design: Ideal for limited work areas or temporary installations.
- Quiet operation: Optimised internal mechanism for low noise levels.
- Installation versatility: Multiple configurations depending on space and process requirements.
- 60° conical hopper: Prevents material retention and promotes complete discharge.
- Easy cleaning and maintenance: Accessible design with no dead zones.
- Multi-product compatibility: Ideal for powdered products with different bulk densities or particle sizes.
FDWATER Design Advantages
- Reliable, durable and low-maintenance equipment.
- Perfectly suited for demanding industrial environments.
- Integration with weighing systems, level control or automation is possible.
- Robust construction using materials resistant to abrasion and corrosion.
FDWATER manual loading hoppers are an efficient, clean and safe solution for installations requiring precise dosing from bags. Their modular design allows easy implementation and adaptation to different plant configurations, while consistently maintaining the quality, operability and safety standards that define our technical solutions.
Applications
Sectors
This system is especially effective in sectors such as:
- Water and gas treatment.
- Furnace and reactor feeding.
- Chemical and environmental processes.
- Solid powder blending and manufacturing.
- General industry.
Tank for preparing lime slurry
Precision, Homogeneity and Safety in Dosing
FDWATER designs, manufactures and supplies slurry preparation tanks for the precise dosing of suspended products such as calcium hydroxide (hydrated lime), powdered activated carbon (PAC), or reagents such as potassium permanganate, calcium carbonate or special clays. These solutions are intended for applications in drinking water and wastewater treatment, desalination and industrial processes that require homogeneous and controlled mixing.
What Is a Slurry Preparation Tank?
The slurry preparation tank is an essential piece of equipment that converts powdered solid products into stable and homogeneous liquid suspensions, ready to be pumped into the process. It allows operation in continuous or batch mode and can be easily integrated with automatic dosing systems, silos or Big Bag unloaders.
Design and Materials
The tanks are manufactured using high-quality technical plastic materials such as:
- HDPE black (high-density polyethylene)
- PPH beige (homopolymer polypropylene)
These materials provide high chemical and mechanical resistance, even in demanding environments. For large-capacity applications, carbon steel tanks coated with epoxy paint are also supplied, with capacities of up to 20 m³.
Their modular design allows the equipment to be adapted to the client’s specific requirements, integrating multiple configurations, sensors and control systems.
Standard Equipment
Each tank includes the necessary components to ensure efficient and safe operation:
- Mechanical high-torque agitator, ensuring homogeneous mixing and preventing settling.
- Water supply panel with automatic solenoid valve.
- Level detectors to control tank filling and emptying.
- Multiple connections for pumping, recirculation, draining or reagent inlet.
- Anti-vortex baffles to eliminate swirling and improve mixing stability.
- Closed design to minimise dust emissions during solid loading.
Available Capacities
- Standard models: from 500 to 5,000 litres.
- Industrial models: up to 20,000 litres (20 m³).
- Custom versions available upon technical consultation.
Key Technical Features
- Lime slurry preparation: maximum homogeneity, adjustable concentration, improved fineness and higher reagent efficiency.
- Activated carbon suspension: continuous and safe mixing, adaptable to products with different particle sizes.
- Integrated pumping system: enables continuous and controlled transfer of the slurry to the point of use.
- Full integration with silos, Big Bag unloaders or automatic dosing systems.
Safety and Emission Control
To ensure a safe and dust-free environment, the tanks can be equipped with:
- Venting systems with wetting nozzles to control airborne dust.
- Filter sleeves that allow air release while retaining solid particles.
- Dust-tight covers and safe inspection openings for maintenance without direct exposure.
Preparation Modes:
Variable Concentration Preparation
- The water volume is kept constant and the lime dosing rate is adjusted.
- Recommended for large flow rates, where the slurry volume supplied to the process is not a limiting factor.
Applications: SWRO (Seawater Desalination Plant), DWTP (Drinking Water Treatment Plant).
Constant Concentration Preparation
- Prepared in batches and the slurry is dosed directly.
- Requires less make-up water, allows fast response and facilitates multi-point dosing from a single tank.
Applications: WWTP (Wastewater Treatment Plant), IWWTP (Industrial Wastewater Treatment Plant).
Note: The slurry does not lose its properties over time, but it must be kept under continuous agitation to prevent settling.
Lime Slurry Pumping
The selection of the pumping system depends on the type of slurry preparation and the specific process design. Transfer pumps or dosing pumps may be selected depending on operational requirements. Lime slurry, up to concentrations of 30%, behaves as a pumpable fluid; however, it may present risks of settling and scaling if appropriate preventive measures are not implemented.
Typical pumping configurations are arranged as 1+1 (one pump in operation and one on standby, with manual changeover via valves) or n+1, depending on the number of processes to be supplied and the required level of redundancy.
Recommendations for pumping system design:
- Maintain a minimum flow velocity of 1.5 m/s to prevent settling.
- Install an automatic flushing system to fully clean the lines after each shutdown.
- Avoid continuous ring pumping systems due to their high energy consumption.
- Minimise pipe length through efficient equipment layout.
- Protect piping from heat, as higher temperatures increase the risk of scaling.
- Where possible, use flexible PVC piping, which is easy to dismantle and clean through periodic manual handling.
This configuration ensures stable operation, reduces maintenance risks and optimises overall process efficiency
Advantages of the FDWATER System
- Modular and adaptable design
- Homogeneous and stable mixing without settling
- Automatic control of filling, mixing and discharge
- Superior chemical and mechanical resistance
- Minimal dust emissions
- Easy integration into new or existing plants
FDWATER slurry preparation tanks are a reliable, safe and technically advanced solution for the precise dosing of suspended products. Their robust and flexible design allows them to cover everything from standard applications to large-capacity or highly complex installations.
Applications
Drinking Water Treatment (DWTP)
- pH adjustment and correction.
- Remineralisation of demineralised or desalinated water (SWRO / BWRO).
Wastewater Treatment (WWTP / IWWTP)
- Neutralisation of acidic effluents.
- Precipitation of heavy metals, phosphates and fluorides.
- Sludge stabilisation and dewatering, and reduction of odours and pathogens
Technical Data Sheet
Others
Activated Carbon Silo: Storage, Dosing, Slurry Preparation and Pumping.
FDWATER designs and supplies complete installations for the storage, dosing and suspension of powdered activated carbon (PAC), specifically intended for applications in drinking water treatment plants, wastewater treatment plants and industrial processes with gaseous emissions. Our solutions are designed to ensure continuous, precise, safe and low-maintenance operation.
We have extensive experience in solids handling and in adapting systems to the technical characteristics of activated carbon: variable bulk density, suspension behaviour and dust sensitivity.
Main system components:
- Fully equipped PAC silo, with capacities from 5 to 200 m³.
- Mechanical extraction system to prevent compaction or bridging of the product.
- Dosing screw or volumetric feeding system with precise regulation.
- Isolation valve and blockage detector, integrated into the safety system.
- PAC mixing and aqueous suspension system, adapted to different concentrations.
- Pumping system optimised according to product characteristics and required flow rate.
- Automated control panel with full process monitoring.
- ATEX Zone 22 equipment, upon customer request.
FDWATER, Expertise in Solids Handling and PAC
Thanks to our accumulated experience and a proven technical solution, FDWATER’s activated carbon silo and dosing systems overcome the typical challenges associated with this type of installation:
Common problems addressed:
- Blockages and bridging in poorly designed silos.
- Variability in actual dosing rates.
- Excessive dust emissions to the environment.
- Difficulties in suspending or mixing PAC in water.
- Continuous maintenance due to clogging or pumping failures.
Our solutions:
- Specific PAC-oriented design with arch breakers and efficient extraction.
- Automated mixing system with concentration control.
- Pumps adapted for PAC suspensions, with automatic flushing.
- Modular, compact and easily integrable systems.
- Flexible feeding from silo or Big Bag.
FDWATER activated carbon silo installations provide a complete, safe and tailored solution for current needs in drinking water treatment, wastewater treatment and emission control within the industrial and environmental sectors.
Advantages of the FDWATER Activated Carbon Dosing System
- High dosing accuracy, essential due to the cost of the product.
- Ability to operate in continuous or batch mode, depending on process requirements.
- Adaptability to different types of activated carbon, with variations in particle size and behaviour.
- Systems designed to minimise dust, simplify maintenance and enhance occupational safety.
- Fully automated systems, integrable with the client’s control system.
Specific Applications of the PAC Silo System
Drinking Water Treatment (DWTP)
- Adsorption of organic compounds, pesticides and herbicides.
- Removal of Geosmin and MIB (taste and odour).
- Reduction of PFAS, trihalomethanes and emerging contaminants.
- Versatile solution for seasonal contamination events or variable raw water quality.
Wastewater Treatment (WWTP / IWWTP)
- Removal of COD and residual organic matter.
- Adsorption of hard-to-treat contaminants in tertiary treatment.
- Improvement of final effluent quality for discharge or reuse processes.
Industrial Gas Treatment
- Capture of dioxins, furans, mercury and other volatile heavy metals.
- Application in incineration lines, combustion systems and thermal processes.
- Use in combination with alkaline reagents for dry gas cleaning.
Sludge Treatment and Stabilisation by Lime Addition
At FDWATER, we design complete technical solutions for sludge treatment from wastewater (WWTP) and drinking water (DWTP) treatment plants, through the controlled dosing of quicklime (CaO) or hydrated lime (Ca(OH)₂).
This process, known as sludge liming, is widely used for its effectiveness in sludge stabilisation, hygienisation and improvement of physical properties, enabling agricultural recovery or long-term storage under safe sanitary conditions.
Why Stabilise Sludge with Lime?
The addition of lime to sludge serves three fundamental objectives:
- Stabilisation: Fermentation is inhibited and odours are neutralised by raising the sludge pH above 12 for at least 2 hours.
- Hygienisation: Pathogenic microorganisms are eliminated and the biological load is reduced, meeting sanitary regulations for agricultural use or final disposal.
- Moisture reduction: The use of quicklime triggers an exothermic reaction upon contact with the water in the sludge, causing evaporation and improving final dryness, reaching up to 30% dry solids, regardless of the previous dewatering system.
Advantages of Using Quicklime
Although hydrated lime can be used, quicklime offers greater operational advantages:
- Higher dewatering capacity due to the exothermic reaction.
- Significant reduction of odours and gases.
- Improved sludge preservation during storage.
The key to the process lies in ensuring a homogeneous and intimate mixing between the sludge and the lime, thereby optimising the chemical reaction and overall treatment efficiency.
Our Solutions: Integrated Lime Dosing Systems
FDWATER, in collaboration with SOTECMA, supplies complete lime sludge treatment installations tailored to each client’s needs. Our modular solutions cover all stages of the process:
- Lime storage: large-capacity silos, Big Bag systems or bag-breaking hoppers, depending on the supply format.
- Precise dosing: via calibrated dosing screws, adjustable to flow rates from 50 kg/h to over 1,000 kg/h.
- Efficient mixing: paddle mixers with specific geometry that ensure homogeneous mixing without breaking down the sludge structure.
- Final product conveying: screws or specific systems to transport the treated sludge to stockpiles, containers or storage silos.
Applications and Benefits
- Agricultural recovery: stabilised, pathogen-free sludge suitable for use as an amendment for acidic soils.
- Reduced management costs: lower volume, fewer odours, and easier handling and transport.
- Adaptable solution: suitable for municipal and industrial plants, as well as temporary or emergency situations.
Are you looking for an effective solution for sludge treatment?
FDWATER supports you from design through to commissioning. Engineering, supply and technical consultancy to deliver robust, safe and efficient systems.
Challenges When Handling Lime
The use of calcium hydroxide (hydrated lime) in industrial and environmental installations is common due to its effectiveness in pH neutralisation, remineralisation, metal precipitation, sludge stabilisation and other applications. However, its handling presents a series of technical challenges that can seriously affect process efficiency, plant safety and maintenance if not properly managed.
Main Problems Caused by Lime:
- Formation of arches or ratholes in silos
The cohesive nature of lime causes obstructions and blockages in the silo, preventing uniform product discharge. - Dust emissions and environmental contamination
The fine dust generated by lime can escape during handling, affecting occupational health and plant cleanliness. - Blockages and clogging in screws and valves
The product tends to compact, leading to blockages in extraction and dosing equipment. - Variations in slurry concentration
Poorly homogeneous mixtures cause fluctuations in treatment quality and reagent consumption. - Scaling in pipes and pumps
Lime tends to settle or form deposits, resulting in efficiency losses, frequent maintenance or even plant shutdowns. - Lack of reliable product level indication in the silo
Lime does not allow accurate level measurement without specific systems, which can lead to planning errors or overfilling.
FDWATER Technical Solutions:
Silos equipped with mechanical or vibrating arch breakers
Prevent arch formation and ensure smooth product discharge.
Dust-tight discharge and dust extraction systems
Protect the working environment and reduce the risk of particle emissions.
Dosing screws with isolation valves and anti-clogging systems
Specifically designed for handling cohesive products such as lime.
Automatic slurry preparation tanks with effective agitation and internal washing
Ensure homogeneous mixing, constant concentration and system cleanliness.
Slurry pumps with self-cleaning systems
Prevent scaling and improve equipment durability and availability.
Radar or load-based level sensors
Reliable solutions to continuously monitor the product volume in the silo.
Full automation via the control panel
Allows integrated, safe operation of the entire system without unnecessary manual intervention.
With these solutions, FDWATER transforms the challenges of lime handling into an efficient, safe and fully controlled process, tailored to the specific conditions of each plant.