The construction of smashing and scattering machine
The smashing and scattering machine was match on the feeding ratoon rice harvester21,22, which is proven in Fig. 1. The double-channel feeding ratoon rice harvester is a harvester independently developed by our analysis crew for the harvest of ratoon rice in its first season, whose feeding quantity is 4.0 kg/s, chopping width is 3000 mm, and supporting energy is 65 kW. The entire machine consists of a crawler chassis, a header, two units of threshing and cleansing units symmetrically organized on the left and proper, a straw scattering machine, a grain bin, and an influence and transmission system. When the harvester is working, the rice vegetation above the stubble top are reduce off by the cutter and fall into the header, that are pushed to the left and proper feeding inlets respectively by the auger, and fed to the next two units of threshing and cleansing units by the chain scraper conveyor. The clear grain after threshing, separation and impurity removing within the threshing and cleansing room is centrally led into the grain bin by the chain scraper conveyor. The straw is crushed by the smashing and scattering machine at rear and scattered to the 2 crawler rolling areas. Lastly, the grain within the grain bin is unloaded by the grain unloading tube to finish the harvest operation.
Double-channel feeding ratoon rice harvester. (1) double-channel header, (2) observe, (3) threshing and cleansing machine, (4) grain bin, (5) smashing and scattering machine, (6) engine, (7) grain unloading machine, (8) sunshade, (9) conveying channel. (SolidWorks 2020, https://www.solidworks.com/zh-hans).
The smashing and scattering machine primarily encompass essential field, straw deflector, knife curler, repair knife set and so forth. The principle field is related by hinges to the outlet of the threshing and cleansing cylinder of the harvester, from which the straw is discharged. The facet cowl plate of the primary field is supplied with an anti-entangling ring, which is appropriate with the anti-entangling finish cowl on the knife shaft of the shifting knife curler to keep away from the straw winding the knife shaft. There may be an arc straw catching plate between the smashing and scattering machine and the threshing and cleansing chamber. The straw falling on the arc straw catching plate is grabbed by the high-speed rotating knife curler and enters the field of the smashing and scattering machine. Below the mixed motion of a number of teams of shifting knives and stuck knives, the straw is smashed into fragmentized ones. Below the motion of high-speed rotating centrifugal power of the knife curler, the smashed straw is thrown out alongside the tangent route. Lastly, underneath the motion of movement diversion of the straw deflector, the smashed straw is thrown to the 2 crawler rolling areas respectively. The construction and dealing precept of smashed straw are proven in Fig. 2.
Construction and schematic diagram of smashing and scattering machine. (1) threshing cylinder, (2) essential field of the smashing and scattering machine, (3) shifting knife curler, (4) arc straw catching plate, (5) repair knife set, (6) straw deflector, (7) chassis, (8) floor. (SolidWorks 2020, https://www.solidworks.com/zh-hans).
Deflect efficiency of straw deflector
The working precept of the straw deflector is to alter the movement state of the straw after colliding with the deflector underneath the exterior power which is able to change its preliminary place, angle, and velocity, permitting it proceed to maneuver by a brand new trajectory. The straw deflector consists of canopy deflector, internal deflector, and outer deflector. The power states when the smashed straw collides with completely different deflector are related. Taking the straw cowl deflector for example, the power in the intervening time when straw collides with the duvet deflector was analyzed. The article was a chunk of single smashed straw, which was considered a particle, and the affect of air movement on the straw was ignored.
Take the smashed straw because the origin of the coordinate axis, the movement route of the straw because the constructive X-axis route, and the other gravity route because the constructive Y-axis route to determine the aircraft coordinate system as proven in Fig. 3. By analyzing the instantaneous power state of the straw deflector when the smashed straw collided with it, it may be obtained:
$$ alpha_{S4} + alpha_{S0} = alpha_{S2} + 90^circ $$
(1)
Evaluation of deflect precept for straw deflector. (1) smashed straw, (2) straw deflector. Word: msg is the mass of the smashed straw, N; NF is the reactive power to smashed straw when it collides with the deflector, which is perpendicular to the deflector, N; FH is the resultant power of msg and NF, N.
It may be obtained from the triangle similarity relation:
$$ left{ {start{array}{*{20}l} {alpha_{S0} + alpha_{S1} = alpha_{S2} + alpha_{S3} } hfill {tan alpha_{S2} = frac{{N_{F} cos left( {alpha_{S2} + alpha_{S3} } proper)}}{{m_{S} g + N_{F} sin left( {alpha_{S2} + alpha_{S3} } proper)}}} hfill finish{array} } proper. $$
(2)
The place vs = Instantaneous pace of the straw colliding with the deflector (m/s), ms = Mass of the smashed straw (kg), g = Gravitational acceleration (9.8 m/s2), αs0 = The angle between the route of movement and the X axis when colliding with the deflector (°), αs1 = The angle between the route of movement and the duvet deflector when colliding with the deflector (°), αs2 = The angle between FH and damaging Y-axis route when the straw colliding with the deflector (°), αs3 = The angle between FH and NF when the straw colliding with the deflector (°), αs4 = The angle between the route of movement and the FH when the straw colliding with the deflector (°).
It may be obtained by substituting Eq. (1) into Eq. (2):
$$ alpha_{S4} = 90^circ – alpha_{S0} + arctan frac{{N_{F} cos (alpha_{S0} + alpha_{S1} )}}{{m_{S} g + N_{F} sin (alpha_{S0} + alpha_{S1} )}} $$
(3)
It may be seen from Eq. (3) that when the pace route of the straw colliding with the straw deflector is fixed, the change of the angle of the straw deflector will make a distinction to the movement trajectory of the straw on the subsequent second; on the similar time, because of the completely different circumfluence place and preliminary velocity when the straw leaves the knife curler, the collision place of the straw shall be completely different within the Y-axis route when it collides with the deflector. Due to this fact, the angle and measurement of the straw deflector have an important affect on the scattering efficiency of the straw.
Parameter design of straw deflector
Determine 4 is the diagram of smashed straw scattering. From the structural parameters of the entire machine, the positional relationship between the smashing and scattering machine and the observe of the double-channel feeding ratoon rice harvester is proven in Fig. 4B, C. The width of the smashing and scattering machine is LSC. Solely a part of the machine is positioned instantly above the observe with a width of LSC1, similar to the area M contained in the machine; the remaining half is positioned outdoors the observe with a width of LSC2, similar to the area N contained in the machine.
Diagram of smashed straw throwing. (A) Lateral view, (B) High view, (C) Entrance view; (1) body, (2) observe, (3) floor, (4) straw deflector, (5) essential physique of the scatter field. Word: LSC is the width of the smashing and scattering machine, mm; LSC1 is the width of the scatter machine above the observe, mm; LSC2 is the width of the scatter on the lateral of the observe, mm; LDC is the scattering distance of the smashed straw, mm; LLC1, LLC2 is the width of the stubble space on the outer facet of the observe, mm; SDC is the size of the duvet deflector, mm; ζDC is the angle between the duvet deflector and the vertical route, °; hDC is the peak distinction between the tail of the duvet deflector and the outlet, mm; hLC is the stubble top, mm; HDC is the peak from the highest spot of the outlet to the bottom, mm.
Ignoring the air power and interplay between the straw, the straw is just subjected to air resistance and gravity. In keeping with the agronomy necessities of the primary season harvest of ratoon rice, the straw discharged from the harvester shouldn’t cowl the rice stubble, that’s, the perfect state is to scatter all of the smashed straw to the rolling space. As proven in Fig. 4B, A is the scattering space generated from N area underneath the motion of the outer deflector, and B is the scattering space generated in M area underneath the motion of the internal deflector. It may be seen the smaller the A space is, the nearer it’s to the perfect state. If there isn’t a straw deflector, the smashed straw will fall onto the bottom after leaving the knife, all of the straw from M area shall be discharged to zone B, and all of the straw from N area shall be discharged to zone A.
After putting in the straw deflector, the scatter distance of smashed straw may be restricted. As proven in Fig. 4A, ζDC is the angle between the straw deflector and the vertical route. The bigger ζDC was, the farther the straw shall be scattered. When ζDC ≥ 90°, the straw deflector loses its perform of deflecting. Moreover, the bigger ζDC is, the bigger the size of canopy deflector SDC shall be. When ζ = 0°, the smashed straw will collide with the vertical baffle and fall instantly, so it couldn’t be scattered backward and can simply get blocked within the chamber. Within the Precise scattering course of, because of the affect of air, the farther the scattering distance is, the farther the lateral motion of smashed straw shall be, that’s, the quantity of smashed straw scattered outdoors the rolling space will improve. So as to discover the affect of ζDC on the certified fee of the scattering, the ζDC take a look at components are set as 30°, 45° and 60° contemplating the size of the straw cowl deflector SDC and the precise blockage.
In Fig. 4A, hDC is the peak distinction between the tail of the straw deflector and the outlet. The smaller hDC is, the less smashed straw will collide with the straw deflector after flat, up, or down scattering. So as to discover the influence of hDC on the certified fee of scattering, the issue ranges had been set as 0 mm, 100 mm, and 200 mm on the premise of not interfering with different mechanisms totally contemplating the structural relations between straw deflector and body, grain bin, and chassis observe.
As proven in Fig. 4C, the stubble between and beside the 2 isn’t rolled when harvesting, i.e., Q’ S3, QS1 and QS3, and the stubble top is hLC. It may be seen the utmost top of the boundary between QS1 and QS3 ought to be prevented for the straw discharged from M and N zones to falling into the rolling space QS2. Due to this fact, it may be inferred in keeping with the geometric relationship that the next situations have to be met for the internal and outer deflector to scatter the smashed straw into the rolling space relatively than on the rice stubble:
$$ left{ {_{{angle E_{3} C_{2} E_{4} le beta_{y} le angle E_{1} C_{2} E_{4} }}^{{ – angle E_{2} C_{1} E_{3} le beta_{z} le angle E_{2} C_{1} E_{1} }} } proper. $$
(4)
The place βz = inclination angle of internal deflector (°), βy = inclination angle of outer deflector (°).
It may be obtained from the entire machine and the structural parameters of the smashing chamber that βz ∈ [− 14°,13°], βy ∈ [23°,48°]. Due to this fact, the extent of inclination issue of the internal deflector was set as − 10°, 0° and 10°, and the extent of inclination issue of the outer deflector was set as 25°, 35° and 45°.
Simulation take a look at of straw scattering course of based mostly on EDEM
Simulation mannequin and parameter design
Professional/E software program was used to hold out three-dimensional modeling of the smashing and scattering machine and imported it into the geometry module in EDEM software program23,24. The simulated gravity acceleration was 9.81 m/s2, and the fabric of the smashing and scattering machine was chosen as Q235. The entrance of the smashing chamber might give the straw a incorrect approach out, so it was closed within the 3D mannequin throughout simulation.
As proven in Fig. 5, the stubble between and beside the 2 tracks of the double-channel feeding ratoon rice harvester must be saved for the ratoon rice, thus the smashed and scattered straw ought to be discharged into the rolling space relatively than these areas. Due to this fact, 4 baffles with a top of 350 mm whose materials is straw had been organized within the mannequin. The 2 baffles within the center had been 400 mm aside to simulate the rolling space, and the opposite two baffles simulate the stubble boundary, thus three areas had been separated out, which is QS1, QS2, and QS3 in Fig. 5. Within the simulation, the Hertz-Mindlin contact mannequin with out sliding was set amongst particles and between particles and geometric mannequin25.
Simulation sensors setup. (1) baffle I, (2) sq. sensor I, (3) smashing and scattering machine, (4) baffle II, (5) sq. sensor II, (6) baffle III, (7) Sq. sensor III, (8) baffle IV.
A sq. mass sensor II with a width of 400 mm was set on the rolling space, which was used to calculate the accumulative mass m2 of straw falling into the world in steady 3 s when the straw was scattered by means of the machine. Then, sq. mass sensor I and sq. mass sensor III had been set respectively, and the mass of straw scattered on the rice stubble within the two areas of the harvest space was marked as m1 and m3.
The feeding quantity of the double-channel feed ratoon rice harvester is 4.0 kg/s, 2.0 kg/s for a single channel. The straw fed into the smashing machine was set to be 1 kg/s in keeping with the ratio of grain and straw which is 1:1. Throughout every simulation, the knife curler was set to rotate constantly with the pace of 2800 r/min, the overall mass was set to be 3 kg, and 1 kg was generated per second. The overall simulation time was set to five s to cut back the straw residue within the chamber. The particle producing aircraft was organized above the arc straw catching plate, and the size and width of the oblong aircraft had been 496 mm and 150 mm respectively. In keeping with the linear velocity of threshing cylinder, the particles had been set to be − 21 m/s alongside Z axis.
The straw materials was roughly fashioned right into a cylinder with a diameter of 4 mm and a size of about 80 mm to construct the straw discrete ingredient mannequin of ratoon rice, as proven in Fig. 6. Simulation parameters of the straw are proven in Desk 126,27.
Straw discrete ingredient mannequin.
Simulation take a look at design
Since there shall be straw residue within the smashing chamber throughout simulation, and a small quantity of straw will fall outdoors the statistical space, the sum of the mass statistics within the three sq. sensors is taken as the overall quantity of straw. By counting the mass of the straw falling into the three sq. sensors m1, m2 and m3, the proportion of the straw falling into the smashing space ηFZ was calculated as:
$$ eta_{FZ} = frac{{m_{2} }}{{m_{1} + m_{2} + m_{3} }} instances 100% $$
(5)
The place ηFZ = Certified fee of scattered smashed straw within the simulation (%), m1 = Whole mass of smashed straw in sq. sensor I (simulated stubble space QS1) (g), m2 = Whole mass of smashed straw in sq. sensor II (simulated stubble space QS2) (g), m3 = Whole mass of smashed straw in sq. sensor III (simulated stubble space QS3) (g).
ηFZ is used as a parameter to guage the efficiency of straw smashing and scattering machine. The upper the worth of ηFZ is, the higher the efficiency is. Due to this fact, it’s outlined because the certified fee of straw scattering. The scattering impact of straw underneath completely different structural parameters of straw deflector may be analyzed by ηFZ.
On this simulation take a look at, the angle between the duvet deflector and the vertical route A, the peak distinction between the tail of the duvet deflector and the outlet B, the inclination angle of the internal deflector C and the inclination angle of the outer deflector D had been chosen because the take a look at components. In keeping with the design and evaluation of the parameters of the tail of the duvet deflector, three ranges of the 4 components had been chosen for orthogonal take a look at respectively, as proven in Desk 2.
Interplay is an influencing issue to be thought of within the means of orthogonal take a look at design. The interactive discrimination exams between components A and B, A and C, A and D, B and C, B and D, C and D had been carried out respectively. Taking the discriminant methodology of interplay between components A and B for example, there have been 9 mixtures between issue A and B, maintaining C and D unchanged. Taking the certified fee of straw scattering because the index, every mixture was examined as soon as, and the identical went for the opposite 5 teams.
In keeping with the generated interplay curve, if the three curves in every mixture take a look at have related developments, it instructed there was no interplay between the 2 components, or the interplay could possibly be ignored28,29. Lastly, the interplay column was arrange within the orthogonal desk based mostly on the interplay discriminant outcomes and the header of the orthogonal take a look at was designed.
Bench verification take a look at
The construction mannequin of the straw deflector was constructed by the mixture of the optimum structural parameters within the simulation take a look at. The straw deflector was put in on the smashing and scattering machine and match with the double-channel feeding ratoon rice harvester.
The take a look at materials was first season ratoon rice at maturity, and the range was Fengliangyouxiang No. 1. The stubble top above 350 mm was manually harvested and transported to the take a look at base. Then it was threshed for the take a look at.
So as to make the take a look at situations near the simulation take a look at, the best facet (rear view) straw scattering machine of the double-channel feeding ratoon rice harvester was chosen to put in the straw deflector with the optimum parameters obtained from the simulation take a look at. A 400 mm broad and 5000 mm lengthy area is remoted behind the harvester observe with colour strip fabric to simulate the observe rolling space QS2; Stubble space QS3 was between the best boundary of header and the skin of proper observe; The stubble space QS1 is simulated between the within of the left observe and the within of the best observe, and the stubble top is 350 mm. The fabric was solely fed from the header feeding inlet on the corresponding facet of the take a look at facet of the straw smashing and scattering machine. The reel was eliminated and the header was lifted to a top of 350 mm above the bottom. To make sure security, through the take a look at, solely the working clutch on the take a look at facet of the harvester was within the “on” state, the working components on the opposite facet weren’t began, and the working clutch was within the “off” state. Thus, solely the two-way screw auger of the header rotated, and the cutter was stationary. The take a look at website is proven in Fig. 7.
Bench take a look at of smashed straw scattering. (A) simulation of rolling and stubble space, (B) feeding inlet.
Throughout the take a look at, 1 kg materials was fed from the feeding inlet of the header each second for 3 consecutive instances, and the harvester was stopped when the smashing and scattering machine stopped scattering the smashed straw on the take a look at facet. The straw in three areas behind the tracks was collected. Take away the impurities and weigh the remaining MQS1, MQS2 and MQS3. The certified fee ηQS of the straw was calculated. Repeat the take a look at for five instances to acquire the common worth, then the answer formulation of ηQS was:
$$ eta_{QS} = frac{{M_{QS2} }}{{M_{QS1} + M_{QS2} + M_{QS3} }} instances 100% $$
(6)
The place ηQS = Certified fee of smashed straw scattering within the bench take a look at (%), MQS1 = The overall mass of smashed straw in simulated stubble space QS1 within the bench take a look at (g), MQS2 = The overall mass of smashed straw in simulated stubble space QS2 within the bench take a look at (g), MQS3 = The overall mass of smashed straw in simulated stubble space QS3 within the bench take a look at (g).
Discipline take a look at on scattering efficiency of smashed straw
To additional confirm the rationality of simulation take a look at and bench take a look at, the smashing and scattering discipline efficiency take a look at of the straw smashing and scattering machine, which was put in on the double-channel feeding harvester for ratoon rice, was carried out within the rice demonstration base of Si Wu Males Village, Wulin City, Honghu Metropolis, Hubei Province on August tenth, 2020. The ratoon rice selection is Fengliangyouxiang 1, and the sphere take a look at website is proven in Fig. 8.
Discipline take a look at of smashing and scattering machine.
Discipline take a look at was carried out on the scattering efficiency of the smashing and scattering machine based mostly on Conservation tillage equipment-Smashed straw machine (GB/T 24675.6-2009)30 and the certified fee of scattering was taken because the take a look at index.
The double-channel feeding ratoon rice harvester operated at a pace of 0.8 m/s testing two strokes. Choose 3 factors at equal intervals within the two strokes for measurement, and a complete of 6 factors had been examined. Every level was an space with a size of 6 m (i.e., two widths) and a width of 1 m in two adjoining operation strokes. Accumulate all of the straw within the 4 rolling rows within the space, take away the impurity, weight, and report as MSP1; Accumulate all of the straw within the un-rolling stubble space, together with all of the straw fragments protecting the stubble and falling to the bottom between the stubble, take away the impurity, weigh, and report as MSP2. The certified fee ηPS of discipline built-in scattering may be calculated as:
$$ eta_{PS} = frac{{M_{SP1} }}{{M_{SP1} + M_{SP2} }} instances 100% $$
(7)
The place ηPS = Certified fee of built-in scattering within the discipline (%), MSP1 = The mass of the straw within the rolling space (g), MSP2 = The mass of the straw within the stubble space (g).
Moral assertion
Human ethics was not required for this research since human had been solely the operators of the machines relatively than the themes of the take a look at. The collected plant supplies and analysis actions had been in accordance with the legal guidelines and rules of Hubei Province, China. The gathering of ratoon rice straw supplies had been authorised by the paddy discipline proprietor of Chunlu Specialised Cooperative in Honghu, Hubei, China. All contributors gave knowledgeable consent previous to participation.
