Industrial emission control has become a matter of concern, as environmental friendly policies gain ground constantly. Among many other emissions, dust and ash are without a doubt some of the major polluting factors and if not handled properly they can be threat to the well-being of the surrounding area and its population. ASTROFIL Th. N.Akrepi has been active since 1987, in the air filtering and de-dusting field.


Baghouse filters are the most common way to contain dust from industrial emissions. Dust every small particle such us cement, ash, sawdust or even sugar, flour etc. suspended in the air. Keeping the air clean of dust is crucial for environmental and human protection but is also very important for proper production. Small solid particles are quite unhealthy when inhaled but can also affect the electronic and mechanical machinery or even contaminate the final product. This last aspect is disastrous in health and food industries where strict regulations for final products, exist. Our company can install, air filtering application in thermoelectric plants, asphalt plants, foundries, big boilers as well as in cement and limestone industry where dust emissions are common. We are also able to design and manufacture special types of filters that can be used in chemical, pharmaceutical and food industry where powder ingredients are used.


The working principal of a baghouse is that a crude air inlet flow, with relatively high concentration in small solid particles, is guided through a large filtering area of textile either woven or non-woven, by the differential pressure created by a centrifugal fan placed at the outlet. There, only the clean air is let through and the particles are contained on the surface of the filtering area. This area is a sum of numerous textile filtering elements, known as filter bags. Filter bags are cylindrical most of the time, produced in a wide variety of diameters and lengths but can also be of different geometry. Our experience and deep understanding of the filtering process allows an accurate selection of the number and geometry of the filter bags. Fail to do so, concludes to false sizing of the whole air filtering unit. We can manufacture filter bags from various materials such as polyester, PTFE etc. that can easily filter particles down to 1 μm. Filter bags are consumables and their life span is related to their manufacturing quality and their proper design in terms of geometry and material selection.
There are numerous designing aspects one must consider in order to manufacture a baghouse. The air velocity at the filter bags, the total filtering area, the geometry and the material of the filter bag are just few of them. Industrial filtering applications are designed to serve the specific needs of a facility and cannot be used in another one. Our industrial filters are able to handle from small (1.000 m3/h) to very big (300.000 m3/h) flows and with the appropriate material selection, various corrosive chemicals and high temperatures up to 320oC. Having prior experience with almost every kind of situation that baghouses are needed we are sure to design and manufacture one that suites your needs.


For the operation of a baghouse industrial filter aside from the metal frame and the filter bags, key components are the metal wire cages that support the filter bags. Their geometry and feature can vary according to the filter bag they support and special needs of the application. Filter bag cages are metallic light weighted parts and their purpose is to keep the filter bags in place, during the filtering process as well as during the cleaning of the filter bag from the contained dust. Poor design and low quality manufacturing can put unnecessary strain on the filter bag, thus significantly shorten its life time. Our specialized machinery and strict quality control ensures that all the cages manufactured in our facilities are properly welded and free of metallic splines that are often responsible for causing damage to filter bags.


Removing of the contained dust from the surface of the filter bags is necessary for the continuous operation of the baghouse and the unobstructed production of the facility it is placed at. Thus, an automated cleaning system for the bag house is needed. Jet pulse cleaning is the newest of these systems and its working principal is to release periodically a compressed air pulse that travels through the filter bag shaking of the dust , enabling it to filter properly again. Each time a different group of filter bags is cleaned while the others keep filtering. The dust that is shacked of, settles in a hopper at the bottom of the bag house. For this cleaning system to work, a number of electrical and mechanical components are needed such as compressed air tanks, valves for the pulse creation as well as timers and monitors for the automated operation and inspection. ASTROFIL Th. N. Akrepi in collaboration with world famous manufactures is trading top grade valves, monitors and every part needed for the operation of the automated cleaning system. Last but not least special mechanical equipment is needed to remove the contained dust from the baghouse, because it is an air tight sealed installation. For these purpose, a combination of an airlock and a screw conveyor is used, making possible the continuous damping of the contained dust at a selected location without any leaks to the environment.

Bag houses are a cost efficient and trustworthy way to contain small solid particles, protecting that way both personnel’s and population’s health. Those dust emissions that naturally occur in many industries, will be a trouble eventually if let unattended for both the facility’s productivity and the surrounding environment.