RU2199401C2 - Pneumatic separator for cleaning and fractionation of grain material - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: pneumatic separator has separating chamber connected to pneumatic channel and to dust separator. Partition walls and grain material fraction collectors are arranged in lower part of separation chamber and charging device is positioned in upper part of said chamber. Pneumatic channel for connecting fan to separation chamber is divided by wall into upper and lower channels. Perforated (baffle-type) gate is fixed at outlet end of upper channel in the vicinity of material inlet end on one of channel walls. Such construction provides for effective operation of pneumatic separator both in grain cleaning and fractionation modes of operation. EFFECT: simplified construction, wider operational capabilities and enhanced reliability in operation. 2 dwg

Description

 The invention relates to agricultural machinery, in particular to machines for cleaning and separation of grain materials, and can be used in the milling and elevator and animal feed industry.

 The purpose of the invention is to improve the quality of cleaning and processing of grain material due to the operation of the air separator both in cleaning modes and in the fractionation mode of the material, depending on the condition and purpose of the initial heap.

 A well-known grain pre-treatment machine MPO-50 [1], the closed pneumatic system of which consists of a diametrical fan, an air supply channel with an adjustment flap, a pneumatic separation channel with a device for introducing the processed grain mixture into it and withdrawing purified grain, a sedimentary chamber with a device for removing light from it impurities. As a result of the interaction of the air flow with the grain mixture, impurities are released from it having aerodynamic properties that differ from the grain of the main culture.

 The disadvantage of this machine is that it does not separate the source material into fractions.

 Also known is a pneumatic inertia separator PVO-15-20 [2], containing a hopper with a finger type agitator, feeding and throwing in conveyors, a pneumatic channel, a separation chamber, in the lower part of which partitions and collectors of finished fractions with conveyors are installed, and a dust separator is installed behind the separation chamber. This design of the pneumatic inertia separator allows you to clean and fractionate the grain material at the pre-treatment stage. The disadvantages of this separator include the unreliable operation of belt conveyors, which is reflected in the rapid wear of the belts, increased grain damage by the throwing conveyor, as well as additional energy costs for throwing a heap.

 Also known pneumatic inertia sieve-free separator with a developed separation zone PVO-3OR [3]. The separator includes a frame, belt feeder, air system, dividing chamber and receiving conveyors. The air system of the pneumatic separator consists of a block of centrifugal fans, a dividing chamber, devices distributing and regulating the air flow. The presented air separator is characterized by the disadvantages of the previous separator, as well as the complexity of manufacturing and the high metal and energy intensity of the structure.

 In FIG. 1 shows a pneumatic separator for cleaning and fractioning grain material.

 Figure 2 shows the perforated (louvre) shutter.

 The pneumatic separator includes a separation chamber 1 connected to the pneumatic channel 2 and the dust separator 3, equipped with a device for removing dust. In the lower part of the separation chamber, partitions 4 and collectors 5 of fractions of grain material are located, and in the upper part, the loading device 6. The pneumatic channel 2 connecting the fan 7 to the separation chamber 1, the dividing wall 8 is disconnected into the upper 9 and lower 10 channels. In the output section of the upper channel 9, in the material input zone, on one of its walls, a perforated (louvre) shutter 11 is rotatably fixed.

 Pneumoseparator works as follows.

 The air flow generated by the fan 7 is divided into two parts and is fed into the separation chamber 1 through the upper 9 and lower 10 channels. The grain mixture distributed by the loading device 6 is fed by gravity to the separation chamber 1. Depending on the position occupied by the shutter 11, the air separator can work in two modes.

 When the shutter is closed (position 1), the grain mixture moves along the shutter, and the air flow supplied by the upper channel 9 passes through the perforated (louvered) surface of the shutter 11 and the grain layer. As a result, a fluidization of the grain mixture occurs on the surface of the damper, its stratification according to the speed of movement and the separation of some light impurities. The lower layers have the highest rate of soaring, and the upper layers have the lowest. After leaving the damper 11, the grain material enters the zone of action of the air flow supplied by the lower channel 10, is finally distributed according to the speed of rotation and ends up in fraction collectors 5. When the damper is closed (position 1), due to the preliminary separation of the material on the perforated (louvre) damper 11, high-quality separation of the grain mixture into fractions even with a small depth of the separation chamber 1, that is, the air separator effectively works in the fractionation mode.

 With the shutter open (position 2), the depth of the separation chamber 1 increases, and the separation of the grain material begins immediately after the exit of the grain material from the loading device. As a result, the grain material is effectively cleaned of light impurities, but the quality of grain separation into fractions decreases.

 The results of the study of the working process of the presented air separator for cleaning and fractionation of grain material are shown in figure 3 and 4.

 In FIG. 3 shows the dependence of changes in the purity of grain fractions entering the collectors of fractions 5 along the length of the separation chamber 1 (section О-О). Curves 1 corresponds to the closed position of the shutter 11 (position 1). Curve 2 corresponds to the open position of the shutter 11 (position 2).

 Analyzing the presented dependencies, we can conclude that the purity of the fractions of the grain material at a distance of 0 ... 200 mm from the lower edge of the separation chamber is at least 98%. Then, for the first curve, it decreases sharply and amounts to 20%, and for the second curve, the purity is at least 85%. These results indicate that when working with an open damper (position 2), the air separator cleans the processed grain material better.

где V _i- средняя скорость воздушного потока в парусном классификаторе, при которой выделяется i-ая фракция;
δ_i - массовая доля i-й фракции;
n - число фракций.Figure 4 presents the dependence of the change in the average values of the critical speed of the soaring of grain fractions taken along the depth of the separation chamber (section O-O), which was determined by the expression

where V _i - the average speed of the air flow in the sailing classifier, at which the i-th fraction is allocated;
δ _i - mass fraction of the i-th fraction;
n is the number of fractions.

где V_н и V_к - средние скорости витания первой и последней фракций, м/с;
Х - глубина делительной камеры, м.To evaluate these dependences, one can introduce the value of α characterizing the gradient of the change in the average critical velocity of the obtained fractions along the depth of the separation chamber, and as a result, the efficiency of division into fractions. The numerical value was found by the formula

where V _n and V _to - the average speed of the soaring of the first and last fractions, m / s;
X - depth of the dividing chamber, m.

 For curve 2, the coefficient α = 0.002 (m / s) / m, and for curve 1 it is 0.0065 (m / s) / m, which is almost two times higher than the efficiency of separation into fractions during operation of the air separator with an open shutter 11 (position 2).

 Thus, the separation by the dividing wall of the pneumatic channel connecting the fan with the separation chamber to the upper and lower channels and installation in the output section of the upper channel, in the material input zone, on one of the walls of the upper channel with the possibility of rotation of the perforated (louvre) damper, expand the functionality of the air separator and allows it, depending on the position of the damper, to work effectively both in the cleaning mode and in the fractionation of grain material.

LITERATURE
1. Machines for post-harvest grain processing / Century. Oknin, N.T. Gorbachev, A.A. Terekhov, V.M. Soloviev - M.: Agropromizdat. - 1987.

 2. A. S. USSR 1518030. Pneumo-inertial separator / N.I. Kosilov, V.V. Piven ', V.M. Uraikin, V.V. Romanov and A.S. Malikov // publ. BI 40, 1989 (prototype).

 3. A.S. USSR 1510959. The method of separation of bulk mixtures / N.I. Kosilov, N.I. Grabelkovsky, S.A. Aristov, V.V. Piven and A.V. Mironov // publ. BI 36, 1989.

Claims (1)

 A pneumatic separator for cleaning and fractioning grain material, including a separation chamber connected to a pneumatic channel and a dust separator, in the lower part of which there are partitions and collectors of fractions of grain material, and a charging device in the upper part, characterized in that the pneumatic channel connecting the fan with the separation chamber it is disconnected by a wall into the upper and lower channels, and in the output section of the upper channel, in the material input zone, is fixed on one of the channel walls with the possibility of turning perforated (louvre) shutter.

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