Horizontal dry mortar manufacturing plant with no cross-contamination
Typical dry mortar manufacturing mixing plants are either horizontal or vertical designs. Both plant designs have their own disadvantages which can have financial repercussions and major cost implications during a plant’s lifecycle.
In a horizontal mixing plant, raw material silos are placed on the ground and often outside the building. The mixer is located inside the building and can be placed either on the ground or approx. 4 meters above ground level, on top of the bagging machine. Compared to vertical designs where gravity helps the transfer of material from the silos to the mixer, the conveying system used in horizontal designs becomes a crucial component of the installation. Depending on location and product constraints, pneumatic or mechanical conveying systems can be used to transfer materials from the storage/dosing area to the mixer or from the mixer to the hopper located above the bagging machines.
Cross-contamination is one of the main disadvantages of both pneumatic and mechanical conveying systems.
Retention is considerable with mechanical systems as it is very difficult to clean screws, bucket elevators or belt conveyors thoroughly while maintaining high productivity.
Pneumatic systems are not suited to the conveying of materials which are very sticky, colored, or have large particle sizes or high bulk density. Indeed, materials can stick to the wall of the conveying pipes thus contaminating other batches. Contamination can also occur at the level of the filtering system on the cyclone hopper at the end of the pneumatic transfer system.
Another disadvantage specific to pneumatic conveying systems is high energy consumption. Compared to a mechanical system, the ratio is around 7 (75kW for a pneumatic system to 10 kW for a mechanical system). This is due to the fact that the production of compressed air required to transfer materials is a very energy-consuming process.
This transfer system also requires highly skilled personnel for its operation (control of pressure differential and airflow) and its maintenance. Misoperation and lack of maintenance could damage pipes, decrease productivity, and contribute to higher operational costs and reduced profit.
In a vertical mixing plant, raw material silos are located on top of the plant and the materials flow down to the mixer by gravity. The aim of this design is to limit contamination and reduce energy consumption.
The vertical design requires a taller and stronger steel structure which means a much higher investment cost. The seismic constraints of the location can also drastically increase the amount of steel required.
The layout of vertical plants also presents disadvantages: as it is difficult or very expensive to add raw material silos, additive hoppers or another mixing line, it restricts possible future extensions of the plant, unless planned from the outset.
Another issue with vertical plant layout is that maintenance activities are often more difficult due to limited access.
Considering dry mortar manufacturers’ growing requirements for flexible manufacturing plants to meet the rising and fluctuating demand for dry mortar products from emerging markets as well as their strong will to optimize both investments and total costs, Actemium Saint-Ėtienne Process Solutions has developed a new dry mortar plant design called Flexiplant with a scalable and modular layout.
Actemium Saint-Ėtienne Process Solutions’ new concept offers a wide range of benefits. The overall size of the steel frame is reduced and the total frame height limited to 9 or 12 meters depending on layout, which translates into lower building costs for investors.
Not only does Flexiplant provide a reduction in investment costs but operating costs are also lowered due to its patented breakthrough mechanical transfer technology combining a carousel and a skip.
Unlike screw conveyors and bucket elevators, the Flexiplant conveying system ensures there is no cross-contamination thanks to the high surface finish of the mobile hoppers.
Furthermore, the Flexiplant mechanical transfer system consumes much less energy compared to pneumatic conveyors. Due to its simple design, this conveying system is easy to access, simple to operate and requires little maintenance. In addition, the conveying system with mobile hoppers leads to shortened production cycle times (= masked time) and higher productivity.
Another benefit of Flexiplant is the high precision weighing system. The weigh scale module is completely independent from the mixer module and thus not exposed to vibrations from the mixer.
To ensure cleanliness of the plant during operation, the conveying system as well as the mixer module are fitted with a complete dust-removal system.
Flexiplant can be supplied with the PRODOSE control system software.
To meet the market’s requirements for short delivery and short mounting times while ensuring the highest level of quality, Flexiplant modules are pre-mounted and pre-tested in the workshop before shipment in containers.
Flexiplant is a cost-efficient design for a very wide range of industrial applications using dry processes.