Complete factory in Djelfa, Algeria.
Complete factory with a production capacity of 140,000 t/year.
3 shifts day, 6 days a week and with an average daily production capacity of 412 tons of fired product. Raw material processing is based on dry grinding.
Clay preparation, grinding and extrusion.
Clay coming from the quarry is supplied to the primary crusher by means of a box feeder. Having been crushed, it is delivered to a hammer mill provided with a feeder at the exit. Clay preparation is completed in a mixer where it is mixed up with water to obtain a suitable moisture rate and a homogeneous blend. A partial compression is also applied for a preliminary cohesion of the mixture. The resulting clay body is stored in an ageing shed.
The ageing shed is an essential stage since it provides the following advantages:
- Ensuring continuous flow in the manufacturing process, if access to the quarry is hampered by weather conditions.
- Providing a better homogenisation, in terms of moisture, of all particles within the mixture, thus ensuring the ageing of clay.
- Efficient absorption of eventual irregularities present in the layers of clay forming the quarry, in order to obtain a final mixture with a constant composition.
When clay preparation is completed, clay is collected from the ageing shed by means of an excavator and it is delivered into a box feeder for the supply of clay to the brick manufacturing line. The clay body is supplied to a primary roller crusher in order to eliminate those grains that may still remain to obtain a really fine grain size.The resulting clay body, a homogeneous, plastic blend suitable for being shaped, is delivered to the extruder.
The extruder unit consists of a large feeder-mixer and an extruder. The homogenisation of the mixture is completed in the feeder-mixer before being transferred to the extruder.
The extruder shapes it in a vacuum chamber in order to increase its plasticity and cohesion so the porosity of the fired product is lower. Ware is forced out the extruder through some dies to obtain the desired format.
Green ware handling.
The resulting clay column is shifted to an automatic cutting line, consisting of:
- Motorless, adjusting, mobile belt.
- Primary cutter.
- Grouping belt at the exit of the primary cutter.
- Multi-wire cutter.
- Cutter outgoing belt with a re-routing system for the supply of ware to the loader.
- Accelerating roller belt consisting of a re-routing mechanism, multi-chain conveyor with dead roller table.
Green ware is delivered to the loading line by means of an automatic pusher, consisting of:
- Return table, outfeed pusher and ware loading on trays.
- Roller arm for loading trays.
The unloading of dry products is simultaneous to the loading of green ones thanks to the push exerted by the edge of the loading arm on dry products when loading green ware on racks. This way, dry products are set on a discontinuous conveyor.
A “Celeris” rapid dryer was considered the best option to ensure the highest production rate while obtaining a high quality final product. This model of dryer is equipped with a large-scale longitudinal ventilation system and it consists of two overlapped drying canals. Products are loaded on racks moving in the reverse direction to the hot air flow.
- Interior width: 6.94 m
- Interior height: 2.19 m
- Length: 78.3 m
- Drying cycle: 3h. 40 min.
The advantages of this type of dryer are the ones below:
- Rapid and high quality drying of products.
- Very accurate adjustment of the drying cycle.
- Mechanical simplicity: easy assembly and low maintenance cost.
Handling of dry products.
Dry products coming from the dryer are arranged in two rows on a re-routing roller table. They are shifted by means of a multi-chain conveyor to a re-routing table in charge of making layers of ware. Resulting layers are pushed by a lowerable gate to a belt conveyor. A turning gripper stacks two layers and then a triple gripper loads them on kiln cars.
The firing process is performed in a traditional tunnel kiln equipped with state-of-the-art technology and with an entirely automated regulation system. It has been specially designed aiming to:
- Obtain the best results in terms of product quality.
- Provide it with efficient regulation systems to ensure a flexible operation and a broad control of the firing cycle.
- Width: 5.2 m
- Height: 3.2 m
- Length: 122.7 m
- Maximum temperature: 1100 ºC
- Fuel: Natural gas
- Side and top burners
The main characteristics of this kiln are the following ones:
- Air-recirculation to avoid the tendency to temperature stratification and to air flow in the most easily accessible areas such as the kiln roof and the sides.
- Accelerated cooling after the firing area for a better control of the cooling process and a uniform quality of products.
- Waste recovery equipment to control the cooling curve throughout the whole area.
- Overpressure created by axial fans to improve pressurisation in the firing area and homogenisation over the whole load.
- Easy and broad control over all the parameters taking part in the firing cycle.
The automatic control of the kiln is performed by an EQ PC program designed by EQUIPCERAMIC which allows for the automatic control, supervision, visualisation and adjustment of both the kiln and the dryer.