Dust generation and filtration methods
Powders arise as a result of processes such as spraying, shredding, cutting, drilling, and abrasion during the production phase. Dusts with values of 300 microns and below are generally found below 60 microns in breathing air as a mixture in air or different gases. Dust that causes dust accumulation in the lungs, also called pneumoconiosis, is between 0.5-5 microns.
Transport, discharge, storage, use, etc. of powdered or dusty raw or semi-processed materials without a protective filter system. activities cause negative effects from dust. This situation causes unwanted health problems.
The information on the website of the Turkish Thoracic Society Environmental and Occupational Lung Diseases Working Group is as follows:
The last accepted definition of pneumoconiosis known as dust diseases of the lung is “the accumulation of inorganic dust in the lungs and the tissue reaction that develops against it”. We can show coal worker pneumoconiosis, silicosis, asbestosis and siderosis as examples of the diseases collected under this title.
Pneumoconiosis accounts for half of the formal occupational respiratory diseases that are subject to disability, compensation review. The prevalence is predicted to be between 1% and 50%, depending on the state of taking dust control measures in those who work in jobs that cause pneumocosis. Symptoms due to pneumoconiosis usually appear quite late after the initial exposure and are not specific. It is in the form of general respiratory complaints and symptoms. The most important factor in diagnosis is the history of working in a job that causes pneumoconiosis. Radiological findings compatible with pneumoconiosis are the second important finding. However, another important point is to show that these radiological findings are not due to any infection, malignancy or other pathology. Unfortunately, no specific treatment for pneumoconiosis has yet been defined. The treatment approach is basically a general support approach aimed at relieving the current clinical findings and complaints in the person.
The clinical and radiological findings of the person should be followed up at intervals determined according to the severity. It is recommended that people diagnosed with pneumoconiosis should be followed closely by a chest diseases center in their area due to opportunistic infections, especially tuberculosis, respiratory symptoms and findings similar to COPD, pneumothorax, and respiratory failure.
The sooner pneumoconiosis is diagnosed, the sooner adverse effects such as callus in the lungs, respiratory failure, etc. will be. For this reason, it is a social obligation to ensure that individuals who are duly diagnosed early, work under appropriate conditions without causing any loss of personal rights, as well as appropriate dust control measures for those working in pneumoconiosis. The first step in pneumoconiosis is to prevent the dust from reaching the respiratory level of the person in pneumoconiosis workplaces, which are called primary prevention. In addition, the examination of chest radiographs according to international criteria of pneumoconiosis every 2 years according to the type and density of the dust exposed, reducing and even preventing the early exposure of the affected persons.
The most important method to prevent the dust generated from being harmful to health is to reduce the amount of dust in the environment to harmless limits. For this, after measuring the number, structure and diameter of the dust in the environment, the spread of the dust to the environment and the environment should be prevented and the dust should be filtered. The most ideal devices that can be used for this purpose are dust collecting units.
Dust collecting units are manufactured to separate dust and particles in an air stream from the air by a mechanical method and prevent environmental pollution. Filter and capacity selection should be made correctly in order to obtain maximum efficiency in dust collection. In any dust collection system, there is basically an air inlet called distribution bunker and the section where the incoming air is distributed, jetpulse dust filters and the section where filtered dust and particles are collected called collection bunker. In the design criteria, it is necessary to know the properties such as air flow rate, flow rate, temperature, density of the particle or dust.
Filters used in dust collection systems should be evaluated on the basis of filtering efficiency (mgr / m3), pressure loss (mbar), dust separation capacity (gr / m3).
They can be used in enterprises with high dry particle density such as dust collecting units, electrostatic powder paint shops, carpentry shops, yarn mills, dry coffee mills, fabric processing factories. By collecting the particles in it, they cleanse the environment from dust. The air filtered in the dust collecting units is given back to the indoor environment. There is no environmental emission since no air is discharged to the outside environment. The system consists of an air distribution bunker, bag type jetpulse filters and a dust collection bunker. Since it can be connected to your ventilation system, it does not require a separate fan.
Dusty air is sent to the air distribution bunker of the dust collecting unit. As the air dispersed in the air distribution bunker passes through the jetpulse filters, it is purified from the dust on it. Dust separated from the air is collected in the dust collection bunker. The filtered air is given to the same environment and the temperature of the environment is maintained. Dust collecting units, which are manufactured with a capacity suitable for your needs, provide high energy savings compared to the exhaust systems discharged to the outdoor environment, thanks to the feature of returning indoor air to the indoor environment.
As dusty air is attached to the surface of the filters in automatic cleaning dust collecting units, the permeability of the filters decreases due to the dust accumulating on the surface of the filter bag. With solenoid valves that can be adjusted up to 0.1 seconds controlled by an electronic timer, high pressure clean air is transmitted into the venturi through the holes in the blowing pipes. Compressed air coming from the venturi to the filter surface cleans the dust on the filter surface by shaking it with the reverse air flow.
In the online bag filter, while the air loaded with dust or particles is filtered, the bags are cleaned sequentially at the same time. The cleaning sequence is automatically controlled by the electronic string controller. The time controller controls the group of solenoid and pulse valves that direct air flow to the manifolds. Air vents should be aligned based on the venturi center to achieve maximum cleaning efficiency.
Offline filters have the advantages of online jetpulse filters as well as the advantages of the reverse air bag cleaning system. The pods are similar to those in the online jetpulse filter. The cleaning process takes place by cleaning the isolated compartments with compressed air. Offline cleaning feature in dust collecting units is suitable for very light and fine dust. Offline bag filters are generally used for very large air flow rates.
The selection, design and manufacture of dust collecting units, which are produced completely locally, should be made according to your needs. Choosing the modular structure dust collecting units will provide you convenience during assembly, use and maintenance.
İlker KURAN
Alperen Ltd. Şti.