The invention relates to a waste compacting unit according to the preamble of the independent claim directed thereto.

Especially in the more massive compacting of waste, the pressing power needed for the pressing process is produced by an electric pressing motor e.g. by using a hydraulic pump arrangement. Hydraulic fluid pressurized by the pump arrangement is being led through a valve arrangement into a hydraulic cylinder in order to move the pressure piston carrying out the pressing, with a pressing motion taking place in one direction and a return movement taking place in the opposite direction.

In the type of solution described above, compacting of waste takes place in a waste container belonging to the waste compacting unit, wherein each parcel of waste being fed at any given time is compacted with waste mass that has been fed into the waste container earlier. Due to this, such a solution demands massive and efficient machinery in order to produce sufficient pressing power.

On the other hand, there are on the market today also apparatuses suitable for smaller sized compacting of waste, with which waste can be compressed e.g. into a barrel, box or into ordinary waste collecting containers. In these types of waste compactors, a piston movable in the longitudinal direction is coupled with the chassis structure therein, whereby waste can be pressed by the piston into e.g. the types of waste containers described above being placed in a supported manner in the chassis structure of the waste compacting unit. A problem in these types of solutions is first of all the fact that in the use of such waste containers, there is a need for transporting and setting up of separate waste containers onto the chassis structure of the waste compacting unit before the compacting of waste is possible.

On the other hand, these solutions are also based on the compacting of waste as a uniform mass, due to which, the chassis of the waste compacting unit needs to be sufficiently massive and the pressing unit therein must have adequate operating power.

Furthermore, another disadvantage is the fact that like in traditional waste compacting processes, the pressing units in such waste compressors need to be returned into a stand-by position after each pressing movement before the next compressing is to be carried out .

Especially from document EP 1707345 a waste compacting unit is furthermore known, which has at least receiving means, such as an opening, being closable with a lid, for feeding of waste therein, a pressing chamber for compacting a parcel of waste being fed therein at any given time and for removing thereof through an exhaust arrangement belonging thereto, and electric pressing means for compacting the waste parcel and for feeding of compacted waste parcels one at a time on dose principle into one or more waste containers. The pressing means in the essentially horizontal pressing chamber of the waste compacting unit are arranged operable by a continuous pressing movement, wherein they comprise a piston that presses the waste parcels alternatively against counterpart surfaces in the pressing chamber at opposite ends of the pressing chamber, in order to drop the compacted waste parcels into one or more waste containers through exhaust openings existing at opposite ends. The purpose of the above mentioned solution is especially the treatment of household waste in a way that waste materials differing from one another can be compacted into separate waste containers. In the solution in question, because of the utilization of use of an ordinary electric motor, the pressing power of such a waste compacting unit is rather moderate, which is why the pressing chambers for different kinds of materials are very small especially in order to fit the waste compacting unit into kitchen hardware. Due to the use of the customary electric motor, a typical problem in this kind of waste compacting unit is due to clogging of the apparatus, which requires removal of the waste to be pressed from the pressing chamber in order to recover the functioning of the waste compacting unit.

Therefore, there aren't any apparatuses on the market today suitable especially for smaller sized waste compacting that is sufficiently inexpensive by its acquisition cost and reliable enough in use.

It is an aim of the waste compacting unit according to the present invention to achieve a decisive improvement in the problems presented above and thus to raise substantially the prior art in the field. To achieve this aim, the waste compacting unit according to the invention is primarily characterized by what has been presented in the characterizing part of the independent claim directed thereto.

As the most important advantages of the waste compacting unit according to the invention may be mentioned simplicity and efficiency of the waste compacting process enabled by the same and the applications suitable for use therein, thanks to minimizing the massiveness of applications needed therein and its working power especially by utilizing therein one or more frequency inverter arrangement operated electrical motors, which are arranged to move the piston in the pressing chamber in longitudinal direction e.g. through a direct drive with a screw driven manner or instead, in a belt or a chain driven manner, the frequency inverter arrangement comprising a single-phase current operated frequency inverter, being provided with a programmable logic and the nominal power thereof being applicable for single- phase current. As an advantageous embodiment of the invention, the pressing motor of the pressing means comprises a three-phase electric motor, the power thereof corresponding essentially to the same of the frequency inverter, wherein the power of the one or more electric motors in a waste compacting unit meant especially for handling of small size waste parcels is between 0,2 and 1,5 kW, most profitably 0,4 kW.

Thanks to the invention, the processing performed by the waste compacting unit is therefore possible to be carried out efficiently enough with single-phase current instead of three-phase current thanks to the frequency inverter principle being utilized therewith. As to the frequency inverter principle, the functioning of a frequency inverter is based on semiconductor technique. The frequency inverter rectifies alternating current of an electricity network into direct current . There are two main types of frequency inverters: the ones with an intermediate circuit and straight ones. In the ones with an intermediate circuit, alternating current is firstly converted into direct current and then back to alternating current with a desired frequency. In the straight type, incoming alternating current is chopped with semiconductor switches directly into alternating current with a desired frequency. At present, frequency inverters with an intermediate circuit are more common in practice. Therefore, e.g. direct current converted into an intermediate circuit of a frequency inverter with an intermediate circuit is proportioned in three-phases by three fast semiconductor circuits according to the desired functioning of the motor. In a frequency inverter at present there may also be integrated a so called programmable logic, such as e.g. a microprocessor control, in which information of the motor and parameters having impact on its desired functioning are set. In addition, it may nowadays even be programmed with a machine control, whereby a separate logic control unit is not needed. Because the frequency inverter rectifies the supply voltage, there are in practice single-phase functioning models available that are, however, used for controlling a normal three-phase motor having the lowest acquisition cost . Frequency inverters are able to follow the behavior of the phases of the motor and "listen to" the motor's load situation and its actual rotation speed. By adjusting phase differences and currents, torsion of the motor may be enhanced while, however, keeping the rotation speed in a desired value. Because the speed of the motor is based on the frequency of the supply voltage, it may, according to need, be steplessly adjusted even higher than the electric motor's nominal speed, whereby, however, the driving torque of the electric motor decreases in practice.

The use of a frequency inverter utilized in the invention enables use of the electric motor both with a lower and a faster speed than its nominal speed in certain phases of the pressing process. Because the torque of the electric motor, however, decreases as the rounds per minute rise, in higher speeds there cannot be a too high pressure response. This can be compensated in the frequency inverter use by decreasing the nominal speed of the electric motor in higher pressure responses, wherein its torque rises and at the same time the electric current used by the same stays in desired limits.

The power the waste compacting unit according to the invention requires is minimal, because it is expected only to have as much power as is needed to compress each single waste parcel at a time. On the other hand, in the waste compacting unit according to the invention, each single waste parcel being compressed into a third of its original size is estimated to be enough, when in the compressors executed with customary technique, waste mass is typically expected to be compressed in a relation of 1:10.

Other advantageous embodiments of the waste compacting unit according to the invention are presented in the dependent claims directed thereto.

In the following description, the invention is illustrated in detail with reference to the appended drawings , wherein in figure 1

is shown as a sectional side view a general operating principle of an advantageous waste compacting unit according to the invention, in figure 2

is shown as a side view a cross section of the type of waste compacting unit as shown in to figure 1, and in figure 3

is shown as a view from above a sectional view of the waste compacting unit as shown in figure 2.

The invention relates to a waste compacting unit, which has at least receiving means 1, such as an opening being closable with a lid K for feeding of waste, a pressing chamber 2 for compacting a parcel of waste being fed therein at any given time and for removing thereof through an exhaust arrangement 3 belonging to the unit, and electrical pressing means 4 for compacting the waste parcel and for feeding compacted waste parcels B' one at a time on dose principle into one or more waste containers A. The pressing means 4 in the pressing chamber 2, existing essentially horizontally in the waste compacting unit, are arranged operable by a continuous pressing movement, wherein the pressing means 4 comprise a piston 4d, which presses the waste parcels B alternatively against counterpart surfaces V in the pressing chamber at opposite ends I, II of the pressing chamber 2, for dropping the compacted waste parcels B' into one or several waste containers A through exhaust openings 3; 3a, 3b existing at the opposite ends.

As a furthermore advantageous embodiment of the waste compacting unit according to the invention, the pressing means 4 comprises one or more electric motors 4a operated by a frequency inverter 4a ' , whereby each electric motor is arranged to move the piston 4b in the longitudinal direction s of the pressing chamber 1 e.g. through direct drive in a screw driven manner or on the principle 4c as shown in figures 2 or 3 through power transmitted from the electric motor by a belt or a chain or in the like manner. The frequency inverter arrangement 4a' comprises most profitably a single-phase current operated frequency inverter, being provided with a programmable logic and the nominal power thereof being applicable for single- phase current.

As an advantageous embodiment the pressing motor 4a of the pressing means comprise a three-phase electric motor, the power thereof corresponding essentially to the same of the frequency inverter, whereby the power of one or more electric motors being used in a waste compacting unit, being meant particularly for treatment of small sized waste parcels, is between 0,2-1,5 kW, preferably e.g. 0,4 k . By the small sized waste parcels in this context, e.g. typical household "garbage bag waste" (20-25 1) are meant, weighing a few kilograms at the highest, when instead the waste containers meant for collecting household waste are usually hundreds of liters in volume, the weight limit, set by the forwarding companies for handling, being typically 40-60 kg.

Furthermore as an advantageous embodiment of the waste compacting unit according to the invention, its power supply is arranged by an accumulator battery W, whereby it comprises an inverter assembly for altering direct current to alternating current for driving the pressing motor of the pressing means. Therefore, the waste compacting unit according to the invention may be used in a self-powered manner e.g. by solar power by a solar cell arrangement coupled therewith or in a corresponding principle, by using wind power.

Furthermore as an advantageous embodiment of the waste compacting unit according to the invention, it is provided with weighing means 5 for determining weight of each single waste parcel B. In this context, as a furthermore advantageous embodiment especially with reference to figure 2, the waste compacting unit may also be equipped with cleansing means 8 for keeping the weighing means 5 clean, which may be carried out simply with a wiper, brush and/or the like in connection with the bottom part of the piston 4b, which, while being moved continuously in the pressing chamber 1, cleans the surface of the weighing means 5. At both ends of the weighing plate are arranged closing plates L, by lowering of which, the waste parcel B' having been compacted at each time can be dropped into the waste container A beneath. After the compacted waste parcel B' has been removed, the weighing means 5 can "calibrate" themselves before the next waste parcel is fed into the pressing chamber, wherein cumulative weighing errors caused by possible remainder matter on the weighing means are avoided.

As a furthermore advantageous embodiment, the waste compacting unit comprises a programmable logic 6, such as one or more micro processors, logic circuits and/or the like, in order to control an automatic independent functioning of the waste compacting unit.

Furthermore as an advantageous embodiment of the waste compacting unit according to the invention, it is provided with a wirelessly, advantageously e.g. on cloud server principle or in a corresponding manner, operating monitoring assembly 7 for storing of user- specific registration information related to single waste parcels being brought to the waste compacting unit, for monitoring of the level in the waste container and/or the total mass of the waste being fed therein, for indicating of functional failures and/or exceeding of a total mass allowed for the waste container, and/or for a corresponding purpose. waste compacting unit may therefore be carried out operate with e.g. a user-specific identification, wherein the waste of each user can be registered e.g. for user-specific billing e.g. on cloud server principle etc. Thus the lid K of the waste compacting unit is furthermore arranged to be opened e.g. with an electrical identification for controlled use of the waste compacting unit.

Furthermore as an advantageous embodiment, the waste compacting unit is arranged as a lid structure to be coupled removably with a waste container A. Therefore, the waste compacting unit according to the invention can also be used as a post installation in connection with most different kinds of waste containers.

It is clear that the invention is not limited to the embodiments presented or described above, but instead it can be modified even to a great extent depending on the operating environment and needs at any given time. It is thus first of all clear that as for the mechanical pressing function shown in the figures, it is possible to use different motor, piston and screw coupling arrangements as what has been shown there, in addition to which, it is also naturally possible to execute the piston and the shape of the pressing chamber in a different manner as to what has been shown. Therefore, it is possible to arrange the pressing function e.g. with a rotating piston in a pressing chamber that has a round bottom surface, wherein as a disadvantage as opposed to what has been shown in the figures, is, however, that a rotating piston that executes continuous pressing function especially in one and the same direction requires for compressing moving counterparts at each exhaust opening in the pressing chamber.