Home workshop: DIY chip suction

Recommendation points

• Why is a dust extraction system so important?
• General configuration
• How to choose an air pump
• Piping and flexible ducts
• Filtration systems
• Catchers and other accessories

In the woodworking industry, the dust and shavings removal system is an integral part of the general technical equipment of workshops and therefore must be calculated, designed and installed in accordance with a number of established rules.

Why is a dust extraction system so important?

Carpentry processing is always associated with the abundant formation of side material. It would not be an exaggeration to call the amount of dust and shavings emitted astounding, because dust suspension in woodworking workshops is a real scourge that both home and professional craftsmen overcome with varying degrees of success..

But what is really the necessity and complexity of wood waste disposal? They are represented by a combination of a number of factors, each of which requires solving rather specific problems:

• Problem number 1: low weight of waste products. Unlike the metalworking industry and even working with polymeric materials, wood chips and dust are very light, they slowly settle under the influence of gravity, and besides, particles are extremely poorly connected to each other due to static electricity..
• Problem number 2: the complexity of the technological process. Even in a modest carpentry workshop, there is an impressive list of processing equipment: planers, thickness planers, saws, milling and grinding machines – each technological unit serves as a source of chips and dust. With such a variety, it is extremely difficult to organize an aspiration system..
• Problem # 3: high variety of waste fractions. During the processing, chips, coarse and small shavings, sawdust, dust and powder can be formed. It is difficult to imagine a single filtration system, at each stage of which particles of a certain size are retained, while the creation of a universal filter seems to be an even less likely prospect..
• Problem # 4: Impact on processing quality. Both chips and microscopic dust can build up on the cutting edges or stick to the surface of the part. All this negatively affects the cleanliness of the surface, in addition, the likelihood of contamination of functional units of equipment increases..
• Problem # 5: Danger from processing by-products. This is not at all about the fact that a colossal amount of dust settles on tools and materials or harms the respiratory system. And not even that the abundance of flammable particles is a negative factor in fire safety. Explosions in woodworking workshops are truly catastrophic, because a suspension of finely dispersed combustible particles in the air is nothing but an aerosol-type explosive, similar in destructiveness to an air-gas mixture. No kidding.

The conclusion from the above is that any object of the woodworking industry should be equipped with a dust and chip removal system, and it is desirable that the execution of such a system be performed at a professional level.

General configuration

In general, two types of aspiration systems can be distinguished. The first one is the local filtering complexes, which are supplied with each of the units of the installed processing equipment. The advantages of local installations are most obvious when the equipment is located at a significant distance on spacious sites. There is no need to lay main channels, there is no need to organize an air pumping unit with increased power. At the same time, there is an obvious benefit in energy saving, because the local filtration unit works only when a certain part of the equipment is involved..

Centralized chip and dust removal systems are also not without advantages. They are most beneficial to use in cramped workshops, where space is limited and the layout of the equipment is made as compact as possible. Each piece of processing equipment is connected to a main exhaust stack, which operates almost all the time the workshop is in operation, at least if at least one of the machines is involved. The advantages of centralized aspiration systems are most obvious with a high workload of production, but this approach requires a high-quality organization of the technological process. It should be noted that the general system for the removal of woodworking by-products requires less investment in the organization, but entails more significant costs in the process of use..

At the same time, the organization of hybrid systems is not prohibited. For example, the most involved parts of the complex, such as a circular saw, thickness gauge, milling machine and others like them, can be combined with a common dust removal system. At the same time, machines that are used from time to time, such as grinders or drum grinding, have their own local filtration units. The key rule is that the issue of organizing a system for removing chips and dust should be put at the forefront when creating a closed woodworking workshop and carefully considered before the final decision on the placement of equipment and approval of the technological cycle.

How to choose an air pump

The heart of the entire suction system is the air pump. Regardless of whether the system is local or centralized, its efficiency depends entirely on the performance of this node. You can offer several options: an industrial vacuum cleaner, one or more channel vane fans, or one centrifugal.

In home workshops, vacuum cleaners are used most often as the central unit of the aspiration system. This is explained quite simply: firstly, the performance of such equipment is often quite enough, well, and secondly, the vacuum cleaner itself can be used to clean the workshop, or to quickly clean the workplace and tools. For such purposes, both industrial (construction) vacuum cleaners and household electrical appliances with a capacity of over 2–2.5 kW can be successfully used. It should be noted that there is a big difference between a vacuum cleaner and a chip sucker, but we will touch on this topic in more detail a little later..

Another type of aspiration systems involves the use of high-power duct fans. In fact, this option represents an attempt to adapt equipment for uncharacteristic purposes, nevertheless, such projects have the right to life and, moreover, are successfully used in home and small production workshops. It should be remembered that inline vane fans are extremely vulnerable to the presence of solid particles in the pumped air flow, therefore they are always installed at the end of the cleaning cycle, in other words, such an air pump pumps already purified air, while all elements of the system operate in a vacuum mode. but not pumping.

It is better to talk about the key parameters of the pumping unit in the context of comparing modern vacuum cleaners and chip extractors. There are three such parameters in total: power consumption, volume of transported air, or simply productivity, as well as created vacuum. Without going into technical details, the vacuum cleaner is more designed to tear off particles from the surface, while the chip suction is focused on capturing airborne particles emitted from under the working body, be it a milling cutter, a saw blade or a sanding belt. Among other advantages of the chip suction device, it is necessary to highlight the presence of a collecting bag of impressive volume, as well as the undemandingness of the presence of a separation unit, that is, a cyclone separator, in the system. At the same time, centrifugal fans, which are used in the vast majority of chip extractors, greatly lose in performance if there is a narrowing of the section in the pipeline system. Vacuum cleaners, on the other hand, as part of a general aspiration system, require jamming of outputs on equipment that is not currently being used. Therefore, systems based on vacuum cleaners are best used in tandem with hand tools or, for example, grinding machines, where the gripping area should be located as close as possible to the processing area for the most efficient removal of fine dust, which is the most dangerous. In turn, centrifugal fans are especially useful because of the ability to pump air even with a high content of coarse particles, because the “snail” engine is located outside the flow.

Piping and flexible ducts

Both centralized and local aspiration systems require connecting pipelines through which the waste is moved from the capture zone to the filter unit. The list of materials suitable for the installation of a piping system is very wide.

Initially, flexible ventilation ducts are of the greatest interest. They consist of a polyethylene or polyurethane sheath reinforced with a spiral reinforcing cord. Flexible pipelines are so widely used due to ease of installation, low cost, no need to use swivel fittings and the ability to quickly change the configuration of the system. One of the most important advantages of flexible channels is the smooth turning of the stave, which reduces the overall aerodynamic resistance..

However, flexible piping is not without its drawbacks. We must not forget that there is a fairly strong vacuum inside the channel, especially if the system is connected to a powerful air pump. If most of the outlets of the aspiration system are plugged, the pipeline can simply collapse, such cases are by no means rare. Also, due to their low mechanical strength, the channels are not recommended to be laid on the floor or in areas where they can be damaged. The most budgetary representatives of corrugated hoses have an internal ribbed surface, which is why, when the aspiration system is operating, the pipeline begins to whistle quite noticeably, while the resistance to air flow increases. It is also very common for them to stick to the walls of dust due to the accumulation of static charge..

The advantages and disadvantages of rigid pipelines are exactly the opposite. Yes, in this case, a reliable fastening system is required, there will be more connections, however, due to the inner smooth surface of the pipes, blockages, adhesion of wet chips and a decrease in flow rate do not occur in them. However, it must be remembered that in terms of cost, rigid steel will cost significantly more than flexible ones, besides, the equipment connected to the aspiration system will remain immobilized. In view of the latter, a combination of rigid and flexible pipelines is often practiced: a dust removal system main from metal or PVC channels of a round or square cross section is laid along the ceiling, and then, using special branch fittings, a transition is made to corrugated hoses for connecting equipment.

Filtration systems

The most important functional element of the aspiration system after the air pump is the unit for filtration, absorption and disposal of processing by-products. In this regard, there are a fairly large number of variations, but only a few are suitable for home workshops..

The first and most important element is a separation filter, otherwise called a cyclone. Its main purpose is to separate the largest fragments, such as shavings and chips, so that only a suspension of small particles enters the further cleaning cycle. The cyclone filter device is primitive, which is why many craftsmen make it on their own, nevertheless, the purchased option provides additional advantages. For example, due to distributed feeding, more efficient particle settling is achieved, in addition, in some models, the possibility of wet absorption is provided, which reduces the amount of fine dust at the exit.

Sometimes aspiration systems do not have a filter element other than a cyclone filter. For example, if air is discharged outside, a fine filtration system is simply not required. This approach is not always reasonable: in winter, when the exhaust system with a powerful air pump is operating, heat from the room is emitted almost instantly, which forces the installation of fine filters. In the simplest case, these are conventional collection bags that retain the main part of fine dust, this option is most typical for local installations. The highest quality of air purification is characterized by dust removal systems, the main unit of which is a vacuum cleaner with two or more cleaning stages. On-line vacuum cleaners can also be equipped with a wide range of cleaning elements, although the most commonly used paper bags and corrugated air filters similar to automobile.

Catchers and other accessories

In conclusion, it is worth talking about those elements that are given the least importance, although their importance can hardly be overestimated. We are talking about all kinds of sockets, receiving funnels and casings, as well as about the appropriateness of their use with one or another type of equipment.

As already mentioned, when working on grinding machines, an impressive amount of microscopic dust is formed. When connecting an aspiration system to such equipment, the main focus is on capturing precisely the smallest particles, while large chips can freely fall on the floor and then be collected manually or with a vacuum cleaner. If receiving funnels are used in such cases, the air flow from the working body itself will create turbulence and the capture of fine dust will become possible only if the suction is strong enough. It would be most reasonable to eliminate the suction socket and place the suction nozzle in close proximity to the processing area..

But where sockets are really needed is in milling, turning and sawing machines, as well as planing equipment. Here, the main emphasis is on drawing in large shavings and sawdust, therefore, the best option would be to equip the working area with a receiving casing that repeats the shape of the working body as closely as possible and adjoins stationary surfaces as tightly as possible. Please note that the optimal total cross section of the gap on all sides of the casing should be 1.5–2 times greater than the nominal bore of the channel with which the machine is connected to the dust removal system. At high values, the use of sealing brushes is recommended, this is especially important for milling equipment.