The object of the application is a device for the production of pellets from biomass and agricultural waste for energy purposes

Polish patent PL165547 discloses briquettes which use asphalt and pitch as binding agents. Such binding agents are not preferred due to the environmental protection requirements. Polish patent PL 194 593 describes pellets containing fine coal or coke or sawdust or peat or straw in which collagen obtained from animal hides was used as a binding agent.

Polish Patent Application P.390657 discloses a method of manufacturing fuel pellets or feed pellet characterised in that the shape- forming, vertical, sleeved slots in the horizontal fixed die is are arranged at equal distances in the same planes along the wheel circumference, and the convex, shape-forming, pressing elements are arranged perpendicular to the horizontal fixed die. Convex shape-forming, pressing elements are fixed radially to the wheel rim in such a way that they sink into the vertical sleeved slots and work with each subsequent sleeved slot of the fixed horizontal die. At the same time adequately fragmented combustible organic waste material is supplied to the entire surface of the fixed horizontal die. The patent application also describes the device that implements this method. Polish patents PL 174678 and PL 174972 describe starch and its derivatives modified with urea-formaldehyde resin as a binding agent for briquetting fragmented energy waste.

Polish patent PL201369 discloses the method of manufacturing of solid fuel by homogenisation and briquetting of the ingredients, whereby the key stage of the forming process takes place in a roller crusher.

The main problem of the prior art was the necessity of pre- fragmentation of the biomass to obtain 0.5 - 1.5 cm fraction and, for some technologies, to obtain fraction less than 0.5 cm by using energy-intensive hammer mills. The second problem was the need to lower the moisture content of biomass to the level of 12-16%, which requires additional energy.

The embodiments, according to the invention, allow pelletising biomass fraction of 4-6 cm (fragmented with a standard chopper). Drying of biomass is also not required if its moisture content is not greater than 25%. The solution does not require the use of binding agents, which is necessary in the case of some technologies.

The method of manufacturing pellets from biomass and agricultural wastes for energy purposes involving pre-fragmentation and cleaning of biomass and agricultural waste, according to the invention, is characterised in that 1) biomass fragmented to a fraction of about 4-6 cm and agricultural waste fragmented to a fraction of about 5 cm is fed to the vibropelletiser assembly (7), where the pre-forming roller (31) pushes the biomass into the groves and partially into the forming slots (34) of the main die (25) so that the biomass is pre-compacted and further fragmented;

2) as a result of the rotation of the main die (25), the pre-compacted biomass moves under the pressing roller (26) equipped with punches, which rotates synchronously with the movement of the main die (25) so that the pressing roller punches (25) are driven into the forming slots (34), wherein, simultaneously to the rotation, the pressing roller (25) also vibrates with an impact energy of 2J to 40J and with a frequency of 900- 3500 strokes per minute, which increases the temperature of the formed pellets to about 110-140°C and consequently evaporates the water and sinters the manufactured pellets.

3) protruding from the slots (34) is cut to the predetermined length with the adjustable chopper (39).

In the second aspect the object of the invention is a device for the production of pellets from biomass and agricultural waste for energy purposes, consisting of the feeding table, the chopper drum (4) equipped with the working head (5) and the impurities separator (6), which is characterised in that to the impurities separator (6) there is connected the vibropelletiser assembly (7), to which the belt conveyor is connected (10) for transferring the pellets into the pellet container (11), wherein 1) the vibropelletiser assembly consists of the main unit (12), the drive (13) and the hopper (15) equipped with the filter bags (9), the inspection window (16) located in one of the walls and the fill level sensor (37) of the hopper (15),

2) the main unit (12) is equipped with the pellet discharge (17) located on one of the walls, and the inspection window (18),

3) the hydraulic drive (19) and the main drive (20) are attached to the main unit (12), and the hopper (15) is connected to the main unit (12) with the auger (21),

4) the auger (21) extends to the working assembly of the vibropelletiser located in the working chamber of the body (33), to which a clamping arm (22) is movably attached, on which at least one main pressing roller (26) is located, whose surface is equipped with punches and which is connected via the slider of the vibrating unit with the vibrator

(24) , and at least one pre-compaction roller (31), which is located directly next to the auger (21), and directly under each pressing roller (26) there is the main die (25) equipped with forming slots (34), under the main die

(25) there is the adjustable chopper. (39), whose working surface faces the direction opposite to the movement of the main die (25), wherein one end of the clamping arm (22) is connected with the hydraulic cylinder (32) of the clamping arm drive, located on the body (33) and connected to the hydraulic drive (19).

Preferably, the axis of rotation of the main die (25) is perpendicular to the movement of the main pressing roller (26), Preferably, the axis of rotation of the main die (25) is parallel to the axis of the main pressing roller (26).

Preferably, the elements of the vibropelletiser assembly (7) are located on the supporting frame (14), the hopper (15).

Preferably, the device is equipped with the control panel (8).

Preferably, the vibropelletiser assembly (7) is equipped with the fill level sensor (35) of the working chamber.

The objects of the inventions are described below in the embodiments and shown in the figures, where fig. 1 is the schematic diagram of the device for the production of pellets, fig. 2 - feeding table assembly together with the chopper, fig. 3 - fig. 13 - design of the vibropelletiser and its components.

Fig. 1 shows the schematic diagram of the device for the production of pellets, which includes the following components of the device according to the invention: supporting platform (1), feeding table (2), cover (3), chopper (4), chopper head (5), stones and impurities separator (6), vibropelletiser (7), control cabinet (8) filter bags (9), belt conveyor (10), pellet container (11).

Fig. 2 shows the feeding table (2) with the chopper (3).

Fig. 3 shows the general view of the vibropelletiser assembly, which includes the following elements: filter bags (9), main unit (12), biomass feeding auger drive (13), supporting frame (14), hopper (15), hopper inspection window (16), pellet discharge (17), the inspection window (18) of the main unit (12) and the fill level sensor (37) of the hopper (15).

Fig. 4 shows the rear view of the vibropelletiser assembly, which includes the following elements: filter bags (9), main unit (12), biomass feeding auger drive (13), supporting frame (14), hopper (15), hopper inspection window (16), pellet discharge (17), hydraulic drive (19) and the main drive (20).

Fig. 5-7 show the internal structure of the vibropelletiser. These figures present the following components: biomass feeding auger drive (13), supporting frame (14), hydraulic drive (19), main drive (20), synchronizing gear belt (27), synchronizing gear (28), clutch (29).

Fig. 8 shows the cross-section of the working chamber of the vibropelletiser assembly (7). This figure presents the following components: biomass metering auger (21), clamping arm (22), vibrator (24), main die (25), main pressing roller (26), slider (30), pre-compaction roller (31) and hydraulic cylinder (32) of the clamping arm drive (22)

Fig. 9 shows the interior view of the working chamber of the main unit (12) from the side of the hopper (15). This figure indicated the following: clamping arm (22), main pressing roller (26), pre-compaction roller (31), hydraulic cylinder (32) of the clamping arm drive, vibropelletiser body (33) and the fill level sensor (35) of the working chamber.

Fig. 10 shows the interior view of the working chamber of the main unit (12) from the side of the hopper (15) with the installed synchronizing gear (28), toothed belt (36) of the synchronizing gear (28) and the tensioner (37) of the toothed belt (36).

Fig. 11 shows the cross-section of the interior of the working chamber of the vibropelletiser assembly. This figure presents the following elements: main die (25), pre-compaction roller (31), vibropelletiser body (33) and the forming slot (34).

Fig. 12 shows the detailed view of the components of the vibropelletiser assembly, such as: main die (24), pre-compaction roller (31) and the forming slot (34).

Fig. 13 shows the diagram of the production of pellets. This figure presents the following components: metering auger (21), main die (25), main pressing roller (26), pre-compaction roller (31), adjustable chopper (39), pellet (40) and fragmented biomass (41).

The method of pellet production according to the invention in the embodiment was implemented using the device according to the invention. The device according to the invention includes, on the supporting platform (1), the production line consisting of the feeding table (2) connected via the covered (3) conveyor with the chopper drum (4), which is connected to the working head (5). Between the working head (5) and the hopper of the vibropelletiser assembly (7) there is the impurities separator (6), and the conveyor belt (10) attached to the vibropelletiser assembly that transports the pellets into the pellet container (11). The device is equipped the control panel (8). The chopper drum (4) is inclined relative to the base and rotates. The hopper (15) of the vibropelletiser assembly (7) and the impurities separator (6) are equipped with the filter bags (9). The vibropelletiser assembly (7) consists of the main unit (12) and the biomass feeding auger drive (13), wherein these components as well as the hopper (15) are located on the supporting frame (14); the hopper (15) is equipped with the filter bags (9) and the inspection window (16) located in one of the walls as well as the filling sensor (37) of the hopper (15). The main unit (12) is equipped with the pellet discharge (17) located on one of the walls and the inspection window (18); in addition, the hydraulic drive (19) and the main drive (20) are attached to the main unit (12), and the hopper (15) is connected to the main unit (12) with the auger (21). The auger (21) extends to the working assembly of the vibropelletiser, which is inserted in the working chamber of the body (33), to which the clamping arm (22) is movably attached, on which the main pressing roller (26) and the pre-compaction roller (31) are mounted. The main pressing roller is equipped along its surface with punches and is connected with the vibrator (24) via the slider (30) of the vibrating unit. The pre-compaction roller is located in the immediate vicinity of the auger (21), and directly under the pressing roller (26) there is the main die (25) equipped with the forming slots (34). Under the main die (25) there is the adjustable chopper (39), whose working surface faces the direction opposite to the movement of the main die (25). One end of the clamping arm (22) is connected with the hydraulic cylinder (32) of the clamping arm drive, located on the body (33) and connected to the hydraulic drive (19). The synchronizing gear assembly (28) connected to the main drive (20) is attached to the main die (25), the main pressing roller (26) and the pre- compaction roller (31). The vibropelletiser assembly (7) is equipped with the fill level sensor (35) of the working chamber. The device according to the invention uses interchangeable main dies (25), in which:

1) the axis of rotation of the main die (25) is perpendicular to the movement of the main pressing roller (26);

2) the axis of rotation of the main die (25) is parallel to the movement of the main pressing roller (26);

The device according to the invention was also used as part of a production line mounted on a platform, semi-trailer or container platform. The device is a fully functional manufacturing facility which converts the raw material in the form of bales into a full-value product in the form of pellets. Since all the components are installed on one line, the installation in the existing pellets manufacturing plants the installation and - in the case of the mobile version - the transport is very easy. In the case of the mobile version, the pellets can be manufactured in a location with an abundance of biomass, which greatly reduces the overall production costs.

The raw materials include cereal, rape or corn straw, hay and biomass from mown idle land. Energy crops, i.e. miscanthus or sida, a well as fruit pomace and exotic plants (coconut palm, bamboo, etc.) are a very good source of raw materials.

The output of the device according to the invention depends largely on the type and parameters of the raw material (moisture content and degree of fragmentation) and amounts to, depending to the number of working modules that consist of the main pressing roller (26), the main die (25) and the pre-compaction roller (31), from 0.8 to 1,4 t/h (for two working modules). For one working head, the total installed capacity amounts to approximately 80 kW, which, for an output of about 0.8 t/h, results in a consumption of about 100 kWh per ton of the product.

All the elements of the device according to the invention are installed on the supporting platform (1). This solution has a number of advantages. All the components of the line are optimally arranged so as to enable efficient manufacturing process. The mounting on the common frame facilitates access for servicing. In the case of a mobile version, this solution facilitates loading and transport to the destination site. The first step of the technological process is the loading of the bales of biomass onto the feeding table (2). The scraper conveyor transports the loaded material toward the chopper drum (4). The cover (3) secures the area between the loading table (2) and the rotating chopper drum (4) and holds the partially loosened biomass. The chopper drum (4) is inclined relative to the base and rotates, which facilitates the transport of the material into the vicinity of the working head (5). The working head (5) with hammer knives rotates, which fragments and cuts the biomass into fractions of approximately 5 cm. The working head (5) is equipped with the fan unit, which allows easy transport of biomass to the hopper (15) of the vibropelletiser assembly (7). The impurities separator (6) is located between the working head (5) and the hopper (15). The hopper tank of the (15) vibropelletiser (7) and the impurities separator (6) are equipped with filter bags (9) that reduce the excess pressure in the system, and prevent dust entry. The finished pellets manufactured in the vibropelletiser assembly (7) are transported by the conveyor (10) into the pellet container (11). Control panel of the line (8) is located at the front of the platform.

The production method of pellets in the vibropelletiser assembly (7) is presented below. The pre-fragmented and cleaned biomass with a fraction of about 5 cm, after cleaning in the separator (6), is transported to the hopper (15). The transport of biomass is carried out pneumatically. The excess pressure created in the installation and the hopper (15) is reduced by the filter bags (9). The amount of fragmented biomass in the hopper (15) is controlled by the fill level sensor(37). The lower part of the hopper (15) is equipped with the metering auger (21). The metering auger (21) transports the fragmented biomass (41) to the working chamber of the vibropelletiser assembly (7). Between the hopper (15) and the working chamber around the metering auger there is a screen for further grinding of larger fractions. The metering auger (21) distributes the evenly fragmented biomass into the working chamber. The amount of biomass in the working chamber is controlled by the sensor (35). The required amount of biomass should be present in the working chamber to ensure the effectiveness of the pelletisation process. Uncontrolled increase of biomass is an unnecessary load to the entire system, especially to the forming rolls.

Evenly distributed biomass in the working chamber is collected by the rotational movement of the main die (25). The main die (25) is equipped, along its perimeter, with the groves of the forming slots (34). The top section of the groves is narrowed. The pre-compaction roller (31) pushes the biomass into the groves and partially into the forming slots (34), which pre-compacts the biomass. The biomass is also further fragmented and plasticised during this process. The pre-compaction of the biomass increases its temperature, which substantially facilitates the granulation process.

The rotation of the die transports the pre-compacted biomass under the pressing roller (26). The pressing roller (26) rotates synchronously with the movement of the main die (25). The pressing roller (26) is equipped with protruding punches with increased hardness. The synchronisation of the rotation of the main die wheel (35) and the pressing roller (26) allows for precise coordination of the operation of the punches and the slots (34) o the main die (25). As a result of this cooperation, the punch concentrically pushes the biomass into the slot (34) of the main die (25).

The pressing roller (26) vibrates in addition to the rotation. The biomass pre-compacted in the main die (25) groves and partly in the slots (34) is transported in the area of operation of the pressing roller (26). The impact energy is from 2J to 40J and the frequency equals 900 to 3500 strokes per minute. These values are continuously adjustable. The rotation together with the impact energy generated by the vibrator (24) very effectively press the accumulated biomass through the slot forming (34) of the main die (25). The speed of pressing the biomass through the forming slots (34) of the main die (25) is much greater in comparison with the traditional static pressing. Furthermore, this process generates significant temperature of about 110°C to 140°C. This phenomenon is very advantageous since some of the water contained in the biomass turns to steam and causes additional lubrication of the microspace between the area of the forming slot (34) of the main die (25) and the formed shape of the biomass that is turned into the pellet (40). Raising the temperature in the range between 110°C and 140°C also facilitates sintering of the surface layer of the pellet (40), which increases its mechanical strength. The adjustable chopper (39) allows the user to adjust the length of the manufactured pellets (40).

The combination of static and dynamic pressing substantially improves the efficiency and effectiveness of the palletising process.