Corrimal Community Men's Shed
has installed a
Clear Vue Cyclone Dust Collector.
Model CVMax 4 HP, 16" Impeller.
It extracts dust from twelve dust producing machines and five floor sweeps. The cyclone dust collector runs continuously with all blast valves closed. This keeps the drive motor current at a minimum level. The cyclone drive is a 4HP (3KW), 2 pole, 2890 rpm, FLC 10 amps, Delta Connected to operate on 220 volt 3 phase. The motor is controlled by a Variable Frequency Drive unit(VFD) supplied from a 20 amp 240 volt AC, 50Hz, single phase supply. Its output is 3 phase 220 volt (see 'VFD Info.' page for more explanation). Note: If the drive is supplied by a 3 phase 415 volt supply then the motor stator needs to be connected in star configuration as the VFD output is about 400 volts 3 phase. [more information shown on the 'VFD Info.' page.]
When starting, the drive automatically ramps up to its operating speed over 10 seconds. This limits and controls the starting current. We set the frequency at 57Hz (Max is 60Hz)...so the operating speed is over 3400 rpm and this gives an air flow of >1900 cfm. A large muffler has been fitted to the cyclone's exhaust and the whole dust collector is then housed in a sound reducing room. No filters installed.
Ten dust producing machines have fully automated dust collection blast valves... see details below. We have four floor sweeps with manual operated blast valves....see demo video further down this page. Our three wood turning lathes each have their own manually operated blast valve to allow the operator to adjust the suction to suit the turning/sanding operation being performed.
When starting, the drive automatically ramps up to its operating speed over 10 seconds. This limits and controls the starting current. We set the frequency at 57Hz (Max is 60Hz)...so the operating speed is over 3400 rpm and this gives an air flow of >1900 cfm. A large muffler has been fitted to the cyclone's exhaust and the whole dust collector is then housed in a sound reducing room. No filters installed.
Ten dust producing machines have fully automated dust collection blast valves... see details below. We have four floor sweeps with manual operated blast valves....see demo video further down this page. Our three wood turning lathes each have their own manually operated blast valve to allow the operator to adjust the suction to suit the turning/sanding operation being performed.
Cyclone Dust Collectors.
How they Work…..
The animation above shows how a typical Cyclone Dust Collector uses the 'Venturi Effect' to remove dust and debris from the high velocity air. The Black ball represents the incoming "dirty" air. As this "dirty" air travels down the cone its pressure drops and velocity increases pushing the dirt/wood/dust/chips outwards and onto the cone wall. The material is then pushed down the wall by centrifical force and drops out into the sealed dust collection bin. At this point the "clean" air (Blue ball) is turned through 180 degrees and extracted up the centre of the cyclone passing through the extraction fan and out.
The Venturi effect is named after Giovanni Battista Venturi (1746–1822), an Italian physicist.
Simply explained....having the angle of the inlet pipe slightly facing downwards and slightly angled to the side wall gives the dust filled air a spiral flow pattern. Also having a long conical section (section B).....the velocity of the dust laden air increases as it moves down the cone in a spiral pattern. The centrifical force throws the dust out to the cone wall and down (remember the pressure is lower & this helps).
These two factors make the Clear Vue Cylones very efficient.
These two factors make the Clear Vue Cylones very efficient.
Cyclone Bagless Vacuum Cleaners like the Dyson work on the same principle...notice the main cone down the middle. Dyson have many small cones in parallel...see diagram below. This allows the Venturi Effect to take place multiple times thus cleaning the air of dust more effectively.
Sir James Dyson got his basic design from a saw mill cyclone dust collector then developed over 5000 prototypes to get it right....click on button below to read more. |
General Introduction to Workshop Dust Collection Systems.
Building a Duct Collection System.
The Cyclone & Machine Dust Hoods.
Click on the photo to enlarge it and read details.
Blast Valve Automation.
Blast valve automation is achieved using a Master/Slave Control Unit which is available in two models. Both models detect the electrical current flowing to the machine. The single phase model has two 240 volt AC outlets mounted on the control box. A single phase machine is plugged into the 'machine' outlet and its current is detected when the machine is running. The detected current signal is fed into the electronics where it is processed and the machine's blast valve is activated via the other 'Dust Valve' 240 volt AC outlet. Selectable timers are built-in to hold the blast valve open after the machine has been turned off. This allows the machine's ductwork to be cleared. A timer is also available to provide a small delay in starting a dust extractor(Shop Vac) unit after the machine is started. This staggers the starting currents.
The second model can be used on a three phase machine. An external current transformer is clipped onto one phase to detect the machine's current.
The Master/Slave Control Unit falls into the 'plug & play' category. This unit coupled with the compressed air operated blast valve makes the automated system very robust and easy to install.
Master/Slave Blast Valve Control Unit - Single Phase Model.
Master/Slave Blast Valve Control Unit - Three Phase Model.
The Master/Slave Power Control Units along with the pneumatics were designed and built in-house.
Modifications to the Sanding Station.
January 2019.
The modifications carried out in 2014 turned out to be unsatisfactory. The dust hoods over the disc sanding wheel, belt sander tail as well as the bobbin sander were inefficient. We decided to purchase a new Jet Bench Top Oscillating Spindle Sander Model JBOS-5 with changeable spindles. Since this machine was taller than the previous one we decided to make a whole new table with one end lower.
From the photos below you can see the various changes we have made to all the duct work around the sanding station. This included installing a new dedicated automatic DC blast valve on the Jet Oscillating Spindle Sander.
Overall we have increased the amount of 150mm dia. PVC duct used...to increase overall efficiency on the sanding station.
January 2019.
The modifications carried out in 2014 turned out to be unsatisfactory. The dust hoods over the disc sanding wheel, belt sander tail as well as the bobbin sander were inefficient. We decided to purchase a new Jet Bench Top Oscillating Spindle Sander Model JBOS-5 with changeable spindles. Since this machine was taller than the previous one we decided to make a whole new table with one end lower.
From the photos below you can see the various changes we have made to all the duct work around the sanding station. This included installing a new dedicated automatic DC blast valve on the Jet Oscillating Spindle Sander.
Overall we have increased the amount of 150mm dia. PVC duct used...to increase overall efficiency on the sanding station.
September 2014.
The photo below shows the green disc and belt sander with dust collection pipes sucking dust from the bottom only. This has proved to be inadequate, especially with the disc sander where it has been difficult to get our members to only use the left portion of the disc (down rotation section). See diagram below for explanation
The photo below shows the green disc and belt sander with dust collection pipes sucking dust from the bottom only. This has proved to be inadequate, especially with the disc sander where it has been difficult to get our members to only use the left portion of the disc (down rotation section). See diagram below for explanation
Modifications:
The belt sander has also been put into the horizontal position. We have revamped the ductwork and now have suction scoops over the top of the belt and disc units. The disc sander still has the under side suction duct. See photos below showing the top suction scoops....'Leaf Catcha' from Bunnings.
The blue Oscillating Sander is also part of the Sanding Station.
The belt sander has also been put into the horizontal position. We have revamped the ductwork and now have suction scoops over the top of the belt and disc units. The disc sander still has the under side suction duct. See photos below showing the top suction scoops....'Leaf Catcha' from Bunnings.
The blue Oscillating Sander is also part of the Sanding Station.
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Floor Sweep Demonstration.
Below is another design for a Floor Sweep by Appin Men's Shed. This prevents rags & thin plastic sheet etc. from being sucked up into the cyclone.
*See more comments further down this page.
*See more comments further down this page.
The 'Big Boy' Muffler.
The Cyclone's exhaust produces ~93db at 3 metres in the open. With our Muffler fitted it drops to 80db. It further drops to 70db with the Muffler fitted and the 'soundproof' room doors closed.
The general rule of thumb is, if you can drop the sound level by 10db then the loudness will reduce by 50%.
The general rule of thumb is, if you can drop the sound level by 10db then the loudness will reduce by 50%.
steps_to_construct_a_big_boy_muffler.pdf | |
File Size: | 50 kb |
File Type: |
Sound Reducing Acoustic Batts can be used in both the muffler and inside the walls of the Cyclone equipment room.
September 2014...Alternate Muffler Construction.
Following a few enquires from other users wishing to construct a similar muffler. There is no reason, that we can see, why the muffler cannot be constructed in a 'coffin' shaped long box (flat sides) from thick MDF sheets. Then lined with the same sound insulation material listed. Tapered conical ends would still be required. It will still require a wire mesh tube down the middle (same as above) to allow the air flow to expand into the cloth and dissipate the noise.
Following a few enquires from other users wishing to construct a similar muffler. There is no reason, that we can see, why the muffler cannot be constructed in a 'coffin' shaped long box (flat sides) from thick MDF sheets. Then lined with the same sound insulation material listed. Tapered conical ends would still be required. It will still require a wire mesh tube down the middle (same as above) to allow the air flow to expand into the cloth and dissipate the noise.
Duct Inspection Port Hole.
Materials:
Muffler Casing Materials came from Ductware P/L - click on link.
12" dia. 60" long, Snap Lock Pipe (5 per pack) - Product Code: DW-60SPBGP12-GA24. (used for air conditioning ducting). Pipe is cut to 1200 mm long to allow two 600mm wide Ecosoft 60 batts to sit side by side.
12" to 8" Reducers - Product Code: DW-R12P8PGA24
Note Casing materials are in imperial sizings - USA. They are made from 24 guage material but thiner gauges are available.
12" dia. 60" long, Snap Lock Pipe (5 per pack) - Product Code: DW-60SPBGP12-GA24. (used for air conditioning ducting). Pipe is cut to 1200 mm long to allow two 600mm wide Ecosoft 60 batts to sit side by side.
12" to 8" Reducers - Product Code: DW-R12P8PGA24
Note Casing materials are in imperial sizings - USA. They are made from 24 guage material but thiner gauges are available.
The Sound Reducing Material came from Acoustica P/L - click on link.
Echosoft 60, 50mm thick, 1200mm x 600mm Batts (6 per pack). Two batts required.
Acoustiflex F8 - we had this grade material. One 1200mm wide layer was used.
The end reducers were filled with standard acoustic batt material.
Echosoft 60, 50mm thick, 1200mm x 600mm Batts (6 per pack). Two batts required.
Acoustiflex F8 - we had this grade material. One 1200mm wide layer was used.
The end reducers were filled with standard acoustic batt material.
Wire Mesh: 25mm x 25mm x 1000mm wide Cage Mesh, we have it in stock...used to make Myna Bird traps.
A 1450mm X 680mm(this includes a 50mm overlap) piece is required. It can be purchased from Hardware and Produce Stores.
A 1450mm X 680mm(this includes a 50mm overlap) piece is required. It can be purchased from Hardware and Produce Stores.
Cyclone Performance Curve - 2014.
An efficient drive, even with three 150mm Blast Valves open together.
The drive runs at 'Idle' (all blast valves closed & current at a minimum) and the load increases as the blast valves open. So overall, running the cyclone in an 'idle' state for the majority of time keeps power consumption to a minimum.
Note: The measured current is the 240 volt single phase current drawn by the variable frequency drive (i.e. Ammeter....see photo further up this page).
Monitoring the 'idle' current over the years gives an indication of leaks and the 'general health' of the system. Our 'idle' current (January 2016) is about ~6.8 amps with no noticeable change in system performance. We have expanded our system in recent years so this could add a little to the 'idle' current.
The drive runs at 'Idle' (all blast valves closed & current at a minimum) and the load increases as the blast valves open. So overall, running the cyclone in an 'idle' state for the majority of time keeps power consumption to a minimum.
Note: The measured current is the 240 volt single phase current drawn by the variable frequency drive (i.e. Ammeter....see photo further up this page).
Monitoring the 'idle' current over the years gives an indication of leaks and the 'general health' of the system. Our 'idle' current (January 2016) is about ~6.8 amps with no noticeable change in system performance. We have expanded our system in recent years so this could add a little to the 'idle' current.
Static Electricity & Fire in the Duct Work.
We have not experienced any static electricity build-up on the PVC ductwork.
At this stage no 'earthing' has been installed on either the outside or inside of the duct network....we will wait and see.
When you place your arm beside the cone section of the cyclone a very small amount is visible by watching the hairs on your arm raise up slightly.
The video below covers an 'earthing system' for static electricity. It also covers fires in the duct system.
At this stage no 'earthing' has been installed on either the outside or inside of the duct network....we will wait and see.
When you place your arm beside the cone section of the cyclone a very small amount is visible by watching the hairs on your arm raise up slightly.
The video below covers an 'earthing system' for static electricity. It also covers fires in the duct system.
Incidents with the Cyclone Dust Collection System
The Root Cause…
For the same reason using Bin Liner Bags can also be dangerous to the motor/impeller drive. The bag can be sucked up into the drive when the drive is started and the liner bag is empty.
The usual outcome of this type of incident is the dust filled air passes straight through the cyclone and out to atmosphere or fills the filter if one is fitted... i.e. no dust collection in the cyclone...just a messy cleanup!
We have operating procedures where the dust level in the bin is checked before and at the end of every operating shift.
We have operating procedures where the dust level in the bin is checked before and at the end of every operating shift.
DIY Manual Operated 100mm Blast Valve.
Ideal for small workshop dust collection systems.
Note: Connect all valve open limit switches in parallel...see circuit diagram below.
Made from 9mm mdf board.
Note: Connect all valve open limit switches in parallel...see circuit diagram below.
Made from 9mm mdf board.
Other Examples...