The plant is based on a 5 tph Spydro hydrator, combined with a vertical HCL classification module, in a compact and fully modular arrangement.

This project represents an important example of how modular lime technology can be applied not only in greenfield installations, but also in complex brownfield sites where available space, access constraints and existing buildings strongly influence the final plant configuration.

A challenging installation area

One of the most demanding aspects of the project was the installation layout.

The new hydration plant had to be installed inside an existing industrial area, between old buildings and structures, with very limited access for conventional installation activities.

The available space was extremely constrained, and the only realistic installation method was to lift the modules from above by crane and place them directly into position.

For this reason, the modular concept of the Spydro plant was particularly important.

The main equipment was supplied as pre-assembled, pre-piped, pre-wired and workshop-tested modules, reducing the amount of installation work required on site and allowing the plant to be integrated into a difficult existing layout.

This approach minimized site activities and helped to reduce the risk normally associated with brownfield installations, where every additional field operation can become complicated by access limitations, existing structures or lack of working space.

Modular design, compact footprint

The Spydro hydration plant is characterized by a compact vertical configuration, specifically developed to integrate the main hydration functions into a reduced footprint.

One of the key features of the Spydro concept is the side-mounted dedusting filter, directly integrated with the hydrator module. This arrangement reduces the need for separate dedusting equipment above the hydrator, simplifies the general layout and contributes significantly to the compactness of the complete hydration unit.

The side filter also improves the process arrangement by keeping the filtration area separated from the most critical reaction zone, helping to protect the filter bags from direct exposure to the highest temperatures and from the risk of overheating.

The system includes:

• quicklime receiving and dosing system;
• loss-in-weight quicklime feeding;
• multistage Spydro hydrator;
• controlled water dosing;
• side-mounted dedusting filter integrated with the hydrator;
• vertical classification module;
• final product and reject handling;
• integrated automation and HMI control.

The combination of the Spydro hydrator with integrated side filter and the vertical classification module made it possible to concentrate the complete hydration and classification process in a very reduced footprint.

This was one of the key enabling factors for the project.

In an installation area where a traditional layout would have been very difficult, if not impossible, the modular design allowed the plant to be placed in the available space while keeping the main process equipment accessible for operation and maintenance.

Workshop pre-assembly and testing

A significant part of the project value came from the level of pre-assembly performed before shipment.

The main plant modules were assembled and tested in the workshop before delivery, including mechanical installation, piping, cabling and functional checks.

This approach allowed the commissioning team to focus on:

• verification of field connections;
• instrument checks;
• motor rotation checks;
• automation sequence testing;
• process parameter adjustment;
• operator training;
• production tests with real material.

For a compact brownfield installation, this is a major advantage. The more that can be completed and tested before shipment, the less uncertainty remains on site.

From cold checks to real production tests

The commissioning activities were carried out over approximately two weeks, including cold checks, functional tests, automation verification and real production trials.

The plant was tested with quicklime having variable particle size, with defined reactivity. This was an important aspect of the start-up, because the hydration process is highly sensitive to the characteristics of the quicklime.

Quicklime particle size, residual CO₂, reactivity, storage conditions and even the time spent inside the receiving hopper can influence the amount of process water required and the behaviour of the material inside the hydrator.

During the tests, the plant was progressively operated at different production rates, from stable low-load operation up to tests to the nominal design capacity.

The importance of water ratio control

One of the key commissioning activities was the identification of the correct water ratio. In a lime hydration process, the water setpoint cannot be treated as a fixed theoretical number. It must be adjusted according to the actual quicklime behaviour. A variation of only a few litres per ton of CaO can change the process response significantly.

Too much water can make the product sticky and heavy, increasing the mechanical load on downstream conveyors and discharge systems.

Too little water can lead to higher temperatures and less controlled reaction conditions.

For this reason, the commissioning team worked by combining several process indicators:

• hydrator stage temperatures;
• mixer motor currents;
• quicklime feeding stability;
• water flow stability;
• material consistency;
• final product moisture and fineness.

The result was a stable operating window, where the plant could react quickly and predictably to small water adjustments.

Reading the plant through temperature and motor current

One of the most interesting aspects of the start-up was the possibility to read the process directly from the plant behaviour.

The first hydrator stages gave the main indication of the hydration reaction. The downstream stages provided useful feedback on product stabilization and drying.

At the same time, motor currents proved to be a valuable diagnostic tool.

When the material became more humid or cohesive, the current increased. When the water ratio was corrected and the material became drier and more free-flowing, the system progressively stabilized.

This confirmed once again that an industrial hydrator is not only controlled by automation logic, but also by process interpretation.

The HMI trends became an important tool for operators, helping them understand how the plant was reacting to each adjustment.

Product quality: excellent fineness and moisture control directly from the hydrator

The production tests confirmed excellent product quality, both in terms of fineness and residual moisture.

A particularly interesting result was the fineness of the raw hydrate directly after the multistage hydrator, before final classification.

The raw hydrate was already largely below 90 µm, confirming the strong process effect of the Spydro multistage hydration system.

At the same time, the final product moisture reached values as low as approximately 0.2%, confirming the effectiveness of the hydration process control and the possibility to finely adjust the water ratio according to the real behaviour of the quicklime.

This result is especially relevant because it shows that the hydrator itself is not only completing the chemical reaction, but also contributing significantly to the physical quality of the hydrated lime.

The immediate response of the plant to small water adjustments allowed the commissioning team to quickly identify the correct operating window, balancing reaction temperature, product consistency, motor current absorption and final moisture.

The HCL classification module then provides the final process step for product control and separation..

Operator training under real conditions

The final commissioning days were also dedicated to practical operator training. Rather than limiting the training to ideal operating conditions, the operators were exposed to real process situations, including variations in quicklime behaviour, water ratio adjustment, reject discharge monitoring and start-stop sequences.

This was particularly useful because lime hydration is a process that requires both automation and operator understanding.

Operators were trained to monitor production setpoint; water ratio; quicklime feeding trend; hydrator temperatures; motor currents; HCL fan operation; separator and reject discharge; alarms and automatic stop conditions; correct shutdown and cleaning sequence.

The goal was not only to show how to start the plant, but to explain how to understand the process. This is essential for stable day-to-day operation.

A fast and effective start-up

Within a relatively short commissioning period, the plant was brought from mechanical and functional checks to real production.

The main operating sequences were tested, the automation system was verified under real process conditions, and the plant was handed over to the customer for operation. The start-up confirmed the advantages of the modular Spydro concept:

1. compact layout;
2. reduced installation time;
3. high level of pre-assembly;
4. limited site work;
5. fast commissioning;
6. excellent product quality;
7. strong process flexibility with variable quicklime.

Some mechanical optimizations were identified during commissioning, as is normal in real industrial start-ups. These follow-up items were discussed with the customer and converted into clear technical actions.

The important point is that the plant became operational and demonstrated its process capability within the planned commissioning window.

Modular hydration technology for complex sites

This project shows how modular hydration technology can provide a practical answer to complex site constraints.

Not every plant can be installed in a clean, open, greenfield area.

In many cases, the real challenge is to integrate new technology into an existing industrial environment, with old buildings, limited access, fixed elevations and restricted installation windows.

The Spydro plant at Kalkwerke Oetelshofen is a good example of this approach.

A compact modular design, combined with extensive pre-assembly and proper commissioning methodology, allowed QualiCal to deliver a modern hydration system in a challenging brownfield location.

The result is a new fine hydrated lime production line, successfully started up and ready for industrial operation.