Until 2001 the Estonian market for autoclaved aerated concrete (AAC) was dominated only by imported production: Aeroc and Raumo Automaatika have established a modern low cost AAC production plant

In 2000, engineers of Aeroc Group Ltd and their partners began implementing a plan for establishing a manufacturing plant in North-East Estonia.

AAC is an ultra-lightweight concrete building material produced from sand, lime, cement, water and an expansion agent.

The finished AAC products weigh as little as one-fifth the weight of ordinary concrete.

As an unknown manufacturer of AAC products, Aeroc had to build up a considerable reputation for quality and claim to be the main supplier in the countries on the Eastern coast of the Baltic.

The key task from engineering companies requested of Aeroc was to create a really competitive manufacturing plant.

Raumo Automaatika has good experience and skills in designing weighing systems and is well-known among Aeroc specialists.

The system supplied by Raumo Automaatika is based on Omron Sysmac PLCs running the Cx-Supervisor SCADA package under Windows NT.

The batching system consists of three main batching weigh vessels for powder materials, slurries and water and one vessel for expansion agent.

The main batching and mixing page shows store tanks of cement, lime, water and weigh vessels used to weigh out the ingredients of raw materials.

After the weighing cycle materials are released into the mixer for a predetermined time.

In conclusion the small amount of the expansion agent is added to mix.

Finally the mixture is cast into the mould.

Filled moulds are moved to the special chamber where a chemical reaction expands the mixture and forms small, finely dispersed air pores.

Conveying of moulds true the chamber is controlled by another SCADA application.

Target values of ingredients in mix design depend on preset values of parameters and current temperatures of raw materials in the storage tanks.

The SCADA system permanently checks the parameters and automatically calculates new target values for each batching cycle.

Formulae for calculating target values are written by script commands in the Cx-Supervisor.

The office supervision is linked with the control system for the plant floor by the Industrial Ethernet.

This solution helps data exchange between these two floors.

User interface that is created in main server provides common area for production information and platform for the development of production applications.

Cx-Supervisor produces batch reports and alarm messages.

Reports and alarms are automatically logged to the data area.

All data is integrated into storage location, giving user access to the chronologically referenced data.

It brings the potency of the Aeroc data base closer to the manufacturing process.

The management of the Aeroc Group is pleased with the plant.

Before 2001 Aeroc was a distributor of imported AAC products.

Today this company is a major indigenous manufacturer of concrete blocks and is known as a reliable supplier and manufacturer in Estonia, Latvia, North-West Russia and Finland.