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Industrial Vacuum Cleaners for Concrete Grinding & Cutting
Modern floor grinders generate huge amounts of very fine silica dust therefore industrial vacuum cleaners are essential /coland should be paired correctly. The greater the grinding power the larger the vacuum. Vacuum filter area is proportionate to floor grinder width.
When grinding and cutting concrete or stone specialised tailor-made M- Class and H-Class vacuum cleaner filters are required to handle large amounts of ultra fine hazardous silica dust particles from 1 micron to 0,3 microns.
Extremely fine silica dust quickly blocks standard filter systems, causing standard carbon brush motors to overheat and burn out.
For continuous concrete grinding you require a vacuum cleaner that has a large pleated filter with an effective automatic, semi-automatic or manual filter cleaning system. Effective filter areas range from 20 000 cm2 up to 60 000 cm2.
There are generally only two types of industrial vacuum cleaners suitable for this type of work load with some being better than others. Personal choice, site conditions and labour skill set also play a factor.
When choosing a suitable vacuum cleaner there are only two critically important factors –
- The type of motor and power output which affects CFM and water lift
- The filter size, type of material of the filter, and the filter cleaning system
Carbon Brush Motors vs Side Channel Blower Motors
Carbon Brush Motors
- Recognition
The general standard in the industry.
Most manufacturers use carbon brush motors varying between a 1000w and 1400w per motor. - Cost
Lower cost of manufacture.
Cheaper initial capital outlay. - Performance
Higher CFM rating and higher water lift rating than side channel blower motors - Life expectancy
Short, rated to last a maximum of 300 working hours. - Run time
Not for continuous use.
Motors need to cool down or overheating and burn out will occur.
Highly susceptible to overheating from blocked filters.
Side Channel Blower Motors
- Recognition
Not very common and found only on large industrial vacuum cleaner units.
Most side channel motors varying between a 1800w and 2400w per motor. - Cost
Higher cost of manufacture and higher initial capital outlay - Performance
Lower CFM rating and lower water lift rating than carbon brush motors - Life expectancy
Considerably longer, rated to from 20 000 to 30 000 hours or 10 – 15 years. - Run time
For continuous use, can run 24 hours a day.
Motors do not need to cool down during use. Not susceptible to overheating from blocked filters.
Automatic Filter Cleaning vs Manual Filter Cleaning Vacuums (not referring to vacuums with no filter cleaning systems at all)
Keeping the filters clean is more important than the filter cleaning system. Also take into account maintenance back-up and spare part availability.
Automatic Filter Cleaning – automatic filter shakers, vibrators and reverse pulse cleaning
Some fully automatic systems just don’t work well enough and still require constant manual cleaning.
These systems are designed to run automatically which makes on-site cleaning difficult. Maintenance costs are also higher.
The best option for high labour cost environments.
Semi-Automatic Filter Cleaning – reverse air flow systems (requires human activation)
Semi-automatic systems (reverse airflow cleaning systems) require a greater skill set to operate, site training and constant monitoring.
These systems offer a good balance as they are semi-automatic and can still be cleaned manually on site.
A good middle of the road option for most and a widely used option today.
Manual Filter Cleaning – manual filter shakers (requires human activation)
Manually operated systems are more labour intensive and are reliant on the operator.
In low labour skill set environments manual filter cleaning systems are easier to operate and understand, less complicated to maintain and harder to break.
The oldest technology of the three options. Tried and tested with the least amount of electronics and the lowest tech designs.
Airflow (CFM) vs Water Lift
Airflow (CFM)
This is the amount of air or air volume being sucked or moved by the motors per minute.
For this application airflow is more important than water lift. Airflow is the ability to pull airborne dust to the filters. The greater the airflow the more airborne dust is removed.
When concrete grinding it will be impossible to remove or suck up all dust generated by the grinding process. The primary concern is the airborne dust not all the dust generated.
The diameter of the pipe is of critical importance – too thin a pipe will reduce the amount of air flow. All the motor power will be restricted by the pipe diameter.
Ideally an industrial vacuum with at least a 50 mm pipe will be required. This may reduce the water lift capability but will increase the airflow.
Water Lift
This measures the actual lifting power of the motors.
This is an important measure when considering vacuum cleaners for water extraction but should not be a consideration when considering vacuum cleaners for dust extraction.
Water is heavier than air. For this application airflow is more important than water lift. Too much water lift will result in dust being sucked against the filter, reducing the cyclonic effect and reducing dust particle drop down.
The filters will clog much quicker and nullify the filter cleaning system. Too much suction power in this application works against the filter cleaning system.
Our recommendations –
- Use large vacuum cleaners with 2 to 3 carbon brush motors with a rating of 2400w to 3600w or a side channel blower motor of at least 1,800kw to 3kw for all floor grinding machines from 250 mm to 650 mm with a 50mm pipe diameter.
Floor grinders larger than 650mm will require 3 phase vacuum cleaners with much larger motors. - Use smaller vacuum cleaners with 1 to 3 carbon brush motors with a rating of 1000w to 3600w for all hand grinders, joint cutters and edge grinders with a 38mm pipe diameter.
