Blowers, effective and versatile equipments
They are mostly offered at the hobbyist level, but there is no shortage of models for professional use, which can often be easily converted into vacuum cleaners/shredders as well. Battery-powered models are enjoying remarkable success, thanks to an ever increasing working autonomy
Among the many hand-operated implements that can be of use on the farm, blowers play a secondary role but can still prove useful on several occasions, for example, to rid areas, corners, and crevices of leaves or other plant material that are difficult to reach with bulkier machines. Conversely, blowers prove to be essential for those who perform green maintenance, not only for leaf removal but also for final cleaning on occasions of mowing, pruning, felling, etc. Although these are tools for purely hobbyist use, there is also a wide range of professional models on offer, which are at the top in terms of performance and mode of operation.
In fact, often further possible options are to transform the blower into a vacuum cleaner (by simply reversing the airflow) and to shred foliage, temporarily storing it in the container provided.
A wide range of offerings. The market offers numerous alternatives in several respects. In terms of mode of use, alongside vast choices of hand-guided blowers, either with an engine (endothermic or electric) integral to the machine body or backpacked, there are also a few high-performance self-propelled models, with gasoline or blend engines of as much as 20-25 Hp of power (see box).
Regarding the type of propulsion, in addition to the classic two-stroke endothermic engine, 4-stroke technology is gaining popularity, which has several advantages, as well as, of course, a significantly lower production of gaseous pollutants. To this end, for the past few years, Stihl has been developing the 4-Mix engine, which, fueled by the standard 2% mineral oil mixture, meets the Euro 5 level limits on pollutant emissions. Noise and vibration levels are also lower than their predecessors.
To further reduce perceived noise, some blowers are equipped with an outlet pipe that embeds a silencing device. In any case, in addition to the noise produced by the engine, for blowers (and for vacuum cleaners), the noise generated by the fan must also be taken into account, so the operator must always be expected to use an appropriate hearing protector, i.e., soundproofing headphones or earplugs, which are sometimes supplied as an accessory to the equipment.
Noise reduction is important not only in relation to the operator but also with respect to environmental propagation in situations where quiet must be preserved, such as - for example - in the vicinity of dwellings and/or in certain time slots. To this end, the provision of an electric motor greatly reduces noise while also zeroing out the production of noxious gases that, given the proximity of the emission point, could be dangerous to the operator, especially in the long run. The many advantages of electric drive, combined with the technological advancement of rechargeable batteries, have long led to the development of numerous ranges of such blowers alongside those traditionally equipped with endothermic engines. In the electric models, brushless type motors are fitted, powered through efficient lithium-ion battery packs, with charging capacities of several ampere-hours and voltage generally not exceeding 48 V (for safety issues in relation to the danger of electrocution). Incidentally, some manufacturers still offer corded blowers powered by normal 220 V mains power.
Types. Several blower models also work easily as vacuum cleaners simply by reversing the direction of fan rotation. In the latter case, there must necessarily be a collecting bag whose useful volume is commensurate with the equipment's working capacity. Usually, professional models are equipped with a container of about 40 liters and more. In some cases, the blower also operates as a shredder of the sucked foliage so as to optimize the filling of the container. A further variable concerns the assembly of the foundational elements of the machine: lighter, mainly hobbyist models consist of a single body, where the motor, fan, rigid blowing tube and accessories are combined into a single unit. Conversely, professional models may have the motor unit and fan back-to-back, i.e., placed in a backpack container, while the blower (or vacuum) duct is flexible and equipped with a handle for orienting it toward the material to be intercepted. On more advanced models, this handle can also be multifunctional, grouping a number of controls into itself so that the implement can be governed with one hand. Moreover, the handle can also incorporate a small monitor of the implement's performance.
The position and design of the dispensing hose handle are of particular importance. For minimum operator fatigue, it should provide the best balance (even if the length is adjustable, for the most effective adaptation to operators of different stature) while having a non-slip surface. The dispenser tube can be fitted with a sturdy metal ring at the open end for maximum protection against possible damage from bumps and creeping on the ground.
Performance. For blowers, highlights include air velocity at the duct outlet, often increased with a venturi tube configuration, and hourly flow rate.
Obviously, this performance is closely related to the power of the engine, although the electric solution, with the same available power, proves to be more efficient than the one with an internal combustion engine. On the subject, in addition to several battery-powered models, Stiga of Castelfranco Veneto (TV) has in its catalog a blower/aspirator/shredder with a 2600 W brushless motor, powered at 220 V, with a maximum airflow of 420 m³/min and a speed of as much as 330 km/h at the intake mouth, with a 45 l bag for accumulating the intercepted material. However, the sound level at the operator's ear is limited to only 75 dB(A), as is the hand-arm vibration level, at 1.7 m/s².
Black&Decker also has multiuse models in its catalog with a 3 kW electric motor powered by mains voltage, equipped with either a blower or a vacuum cleaner tube (with scraper for hard-to-remove debris) and a 72-liter capacity backpack container.
Technical evolution has led to offering models with electronic regulation of the motor speed (and thus of the fan) so as to modulate the air jet best as needed. Connectivity finds implementation on blowers as well. For its models, which are equipped with any engine and power supply, Stihl offers the Smart Connector, which, supplemented with a dedicated app, allows the operating times of the implement to be recorded and transmitted via Bluetooth to a smartphone or tablet and then transferred to a cloud via WiFi or other data connection, for later more in-depth analysis, for example of the fleet in charge of a groundskeeper.
Also self-propelled for high performance
Blowers, as well as vacuum cleaners for leaves and other plant materials, are also available in wheeled and self-propelled versions for cleaning large areas. Fiaba of Camisano Vicentino (VI) markets the X3000 model from U.S.-based Billy Goat, equipped with a 607-cfm Briggs&Stratton Vanguard endothermic gasoline engine that delivers an impressive 23 Hp and is therefore suitable for the maintenance of large parks, resorts, roads and golf courses. The powerful airflow (with a speed of 265 km/h at the outlet, for a flow rate of more than 7,500 m³/h) generated by a 48-cm-diameter fan can be directed to 3 nozzles (right, front and left) equipped with deflectors for jet orientation and individually manageable by the operator using a joystick located on the dashboard. The drive is hydrostatic, with an automatic parking brake. The vehicle is equipped with 4 rubber wheels: the two rear ones are driven, while the front ones, pivoting for steering, are placed on a pivoting axle to be able to easily overcome curbs, unevenness and irregularities in the ground profile. Two stegs, similar to those found on crawler tractors, are used for "zeroturn" steering (i.e., with a minimum radius equal to that of the machine's wheelbase). The vehicle's tonnage (339 kg) made it possible to usefully carve out a small platform at its rear, with a non-slip surface and vertical padded pad at the front, where the standing operator can stand to control the machine's progress, for a maximum speed of about 13 km/h.
Battery packs
In blower/vacuum models equipped with an electric motor, the battery pack is a key element in the performance of the vehicle in relation to the airflow generated, particularly in what concerns the operating range. Lithium-ion technology has made it possible to develop battery packs of an acceptable weight and volume, which are able to guarantee a reasonable working time with one charge cycle. Obviously, models with greater energy requirements have the batteries placed in a backpack for best portability. The spread of battery-powered equipment for manual use has encouraged the appearance of battery packs that are interchangeable between different implements, also with increasing charging capacities. In general, while within the limiting voltage range of 36-48 V (for electrical safety issues), they vary in a wide range of currents, from about 3 to 35 Ah, for a charging capacity between 0.15 and 1.5 kWh, capable of powering motors ranging from 0.8 to 3 kW. Reported useful charge/discharge cycles typically range between 800 and 1,300 or so. A cycle is defined as "useful" as long as the battery pack can accumulate a minimum of 80 percent of its rated charge capacity.
The battery pack's mass obviously varies according to the charging capacity, starting from less than a kilogram for the smallest model incorporated into the structure of the machine-to the 7-8 kg of the one necessarily placed in the backpack. In any case, there are not only individual storage elements inside but also the accompanying electronics, which provide for balancing the charging and discharging currents of the whole assembly. Moreover, more and more often, a small monitor is installed, providing information on the state of charge and sometimes also on the remaining working time. For blowers, battery drawdown is quite demanding, as these are implements that are usually used for a significant time at maximum power.
