Hand-held and masonry saws are heavily used in construction industry. These machines are mainly used for cutting thorough different kinds of materials like concrete, stones, bricks, blocks and pavers, etc. Although masonry saws and the masonry cutting process are integral part of many construction projects, the cutting process creates high levels of dirt and dust. Very often, this dust contains dangerous silica materials. Therefore, working with masonry saws and breathing the dust with silica content can lead to serious respiratory health problems, or more seriously, it can result in damaging the lung tissue, leading to a lung cancer. Fortunately, today on the market there are masonry saws that come with dust control mechanisms for higher protection. Generally, there are two main dust control mechanisms for minimizing dust exposure when cutting with masonry saws. The following text will describe the most common ways to control the dust when masonry saws are used.
Wet Cutting And Suspension Of Dust With Water – Water can be used for minimizing and suppressing dust which is generated when either hydraulic, pneumatic or gasoline powered masonry saws are used. The water is directly applied on the cutting blade through one or more nozzles. This wet system is powered by combustion engines or by compressed air. However, such wet systems for dust control should not be used on electrical powered masonry saws. One very effective wet cutting system is the portable pressured tank system. Most masonry saws are equipped with this portable system. Generally, it comes with polypropylene bottle that has a capacity of holding approx eight liters of water. The bottle is connected to the blade by a plastic tube. A on/off valve is used to control the water supply. The mostly recommended water flow rate for effective dust suspension is 0.5 liters of water per minute. Applying less water will result in less effective dust suspension. Also, more water will not result in higher dust control.
Local Exhaust Ventilation System – The local exhaust ventilation system is used in masonry saws as an exhaust hood which surrounds the blade of the saw. A flexible hose is used to connect the hood with one industrial vacuum cleaner. The function of the vacuum cleaner is to create suction so that dust can be quickly captured. For best results, the hood should always be close to the material or object that is being cut. Adjustable hoods are preferred because they can accommodate various cutting depths. The cleaner needs to have the following features for effective dust suspension:
- flow rate capable to capture and to move the amount of dust generated by the masonry saw to the vacuum source
- very effective particulate air filter which minimizes the chances of dust being released from the vacuum cleaner
- an air filter replacement indicator like a pressure gauge
- high effective motor that draws more than 10 amps
This system however doesn’t provide the wet slurry which is associated with the wet dust suspension.