Purpose:
Plansifter РФХ-4 is designed to separate the original grain mixture into fractions that differ in grain size, as well as to separate small impurities (seed) from the main culture. The separator is installed in the elevators after separators for grain pre-cleaning.
Specifications:
| Characteristic |
РФХ-4 |
| 1. Technical productivity with the moisture content of the original grain mixture not exceeding 15% and an average density of 700-800 g/l, t/h. |
50 |
| 2. Efficiency of separation of fine grain fraction (sieve passage, 2 x 20), %, not less |
60 |
3. Efficiency of cleaning grain from small trash impurities in fractions
(sieve passage 1.7 x 20), %, not less |
65 |
| 4. Vibrations of the sieve body: |
uniform, circular, translational in the horizontal plane |
| 5. Circular vibration frequency of the sieve body, s-1 (rpm) |
4,08 (245) |
| 6. Radius of circular vibrations of the sieve body (adjustable by removable weights of the balance bar), mm |
from 35 to 40 |
| 7. Rated power of the electric motor, kW, no more |
5,5 |
| 8. Air consumption for aspiration, m3/h |
600 - 700 |
| 9. Number of receptions (sections), pcs. |
4 |
| 10. Number of sieve frames in a section, pcs. |
16 |
| 11. Sieve frame dimensions (length, width), nominal, mm |
940 х 530 |
| 12. Sieve frame dimensions (length, width), nominal, mm2 |
31,08 |
| 13. Overall dimensions, mm, no more: |
|
| - Length |
2 800 |
| - Width |
1 700 |
| - Height (to the receiving plate) |
2 450 |
| 14. Weight (excluding the mass of spare parts-ЗИП), kg, no more |
2950 |
| - Including oscillating parts (without product) |
2800 |
Design and principle of operation:
Separator is collapsible design and consists of a sieve body, a system of supporting, receiving and exhaust devices. The screen cage of the separator is suspended by hangers from the ceiling frame via steel ropes. Steel ropes are inserted into the lock and fixed with wedges. Adjustment of the rope length and horizontal installation of the sieve body is carried out by a tension rod. Receiving devices are fixed on the bar rollers to the ceiling frame, designed to regulate the quantitative feed of the original grain in sections and to connect the gravity feed of grain and the air duct of the aspiration system. Cloth sleeves are fastened to the inlet pipes and inlet pipes of the sieve housing, to the housing bottom pipes and to the floor pipes.
A drive is mounted on the cover of the sieve casing of the cabinet construction, which transfers rotation to the balancing mechanism using a V-belt transmission. The sieve body consists of four sections connected on a supporting frame into one block. Each section is closed on one side by a door, inside of which there is a junction box and a triple box, a wall, and on the other side - junction boxes with bypass channels of a similar design. Bypass channels and distribution boxes are designed to distribute and direct the flow of the grain mixture over the working bodies. The sections are covered with a roof at the top, with a bottom at the bottom. The inlet pipes are mounted on the roof, serving for uniform distribution of the grain mixture on the receiving frames, and on the bottom and doors - outlet pipes. On the sides, the sections are covered with coating. The guide sections with coating on one side and a longitudinal partition of the supporting frame on the other form side channels.
The balancer mechanism consists of a shaft, upper and lower balancers, secured to the shaft with clamps and washers. There is a cabinet under the upper balancer. The shaft rotates in the upper and lower bearing units. The upper bearing assembly consists of a housing, roller and thrust bearings, a bushing and two thrust rings, while the lower one consists of a housing, a roller bearing and a bushing. To retain grease, prevent dust and dirt from entering the housing, cuffs are installed in the bearing caps. There are removable weights on the balancing mechanism to regulate the vibration amplitude of the sieve body. The rotating parts of the balancing mechanism are covered with guards.
Sliding frames are installed in the guides of each section. The separator frame consists of an all-metal pallet and a wooden insert frame. The inset frame consists of a wooden frame, divided by internal partitions into six equal-sized cells, on top of which a sieve cloth is fixed, and on the bottom - a welded support mesh No. 10-1. Cleaning of the sieve cloth is carried out by wandering cleaners located between the sieve and the mesh, one in each cell of the frame. The cleaner is a triangular polyurethane plate with a spherical support shoulder in the centre. The group of the upper 12 frames of each section of the separator has a sieve with apertures of 2.2x20 mm, and the group of the lower 4 (sub-sowing) frames - 1.7x20 mm. Sieve frames are installed in the cabinet in accordance with the functional diagram of the separator, while the windows at the frame for the outlet of the through product should be directed towards the cabinet casing.
The receiving device consists of a frame, two receiving boxes and branch pipes. Receiving frame welded from bent profiles. Plates with holes are provided for receiving boxes. Hole brackets are available for attaching the receiver. Receiving boxes are designed for connecting gravity and aspiration ducts. The branch pipes for receiving the product are equipped with sight glasses.
The principle of operation of the separator is parallel and sequential movement of the processed grain mixture along a set of flat horizontal sieves, making a uniform circular translational movement in the horizontal plane. As a result of vibrations of the sieve surface, the process of self-sorting of the processed grain mixture occurs, as a result of which fine grain (fine fraction) and small impurities (over-sowing) are concentrated in the lower layer, reach the sieve surface and are sown, and the coarse grain fraction after sequential four passes through the upper 12 frames of each section are removed from the separator. The fine grain fraction and small impurities (overseeding), being combined into a common flow, are fed through the side channels of each section to the four lower underseeding frames, on which the fine fraction is collected by descent, and the small impurities (overseeding) are separately removed from the separator through the passage.
Operating procedure:
During operation of the separator, more attention should be paid to:
- Equal load of all sections;
- Tightness of the sieve body, preventing the release of dust to the places of joint;
- Litter one fraction into another;
- Condition of all oscillating units and parts, quiet operation;
- Clean sieves, checking the efficiency of the cleaners during the separator stops;
- Efficiency of aspiration.
The radius of the trajectory of uniform circular translational vibrations in the horizontal plane of the sieve separator is regulated by removable weights mounted on the balance bar.
When installing additional weights, it is necessary to ensure that the mass and their location on the upper and lower balancers are the same. If this condition is not met, forces are unfavorably distributed in the bearing assemblies, the horizontal movement of the housing is disrupted.
To determine the average radius of circular vibrations of the sieve body, it is necessary to fix a sheet of graph paper or blank paper on the roof, bring a pencil with the help of a device until it touches the sheet. Start the separator, and after reaching the steady state (after 10-20 minutes) stop it. Measure with a ruler, with an accuracy of 1 mm, the value of the largest and smallest diameters (D 1 and D 2) between the extreme points of the trajectory track left on the paper, and determine the average vibration radius using the formula: Rcp = (D1 + D2) / 4 mm.
