RFH-4
RFH-4

Plansifter RFH-4 (separator) is designed for separation of initial grain mixture to fractions, which differ by granulometric content, and for separation of light foreign matters from main crop. Plansifter is applied at grain storages (elevators) after separators for grain pre-cleaning.

Plansifter RFH-4 (separator) is designed for separation of initial grain mixture to fractions, which differ by granulometric content, and for separation of light foreign matters from main crop. Plansifter is applied at grain storages (elevators) after separators for grain pre-cleaning.


Specifications

Characteristics

Value

Technical capacity (with grain mixture moisture max. 15% and average density 700-800 g/l), t/h                                           

50

Efficiency of small grain fraction separation (sieve hole size 2х20),% min

60

Efficiency of grain cleaning from light impurities in fractions

(sieve hole size 1,7х20), %, min                        

65

Sieve body oscillation mode: uniform circular translation in horizontal plane

Frequency of circular oscillations of the sieve body, с-1 (rpm)

4,08     (245)

Radius of circular oscillations of the sieve body (adjusted by removable weights of the balancer), mm

from 35 to 40

Rated electric motor power, kW, max                  

5,5

Air consumption for aspiration, m3/h 

600-700

Quantity of product inputs (sections), pcs.

4

Quantity of the sieve frames in the section, pcs.

16

Sieve frame dimensions (length, width), rated, mm

940х530

Total sieve area, m2

31,08

Overall dimensions, mm, max:

length

width

height (to the receiving plate)

2800

1700

2450

Weight (without weight of spare parts and instruments), kg, max

2950

including oscillating parts (without product)

2800

Structure and Functioning


Separator (fig.1) is represented by modular construction and consists of the sieve body 5, system of supporting, inlet 4 and outlet devices 9. Separator sieve body is suspended on steel ropes 2 by suspensions 1 to the ceiling frame. Steel ropes are inserted into the lock and fixed by wedges 8. Tension rod 6 provides rope length adjustment and horizontal installation of the sieve body. Receiving devices 4 are fixed with roller bars 3 on the ceiling frame, they are designed for adjustment of grain quantitative feed by sections and for connection of gravity flow ducts for grain supply and air duct of aspiration system. Fabric sleeves 7 are fixed by clamps to receiving devices nozzles and sieve body inlet nozzles, body bottom nozzles and floor nozzles.


Drive, which is assembled on the roof of sieve body with the form of cabinet construction, is transmitting rotation to the balancing mechanism by means of the V-belt transmission. Sieve body (fig.2) is represented by four sections 4 connected on the supporting frame 3 into one block. Every section is closed by the door 6, inside which distribution box 7 with triple box 8 (for distribution into three flows) and wall are placed, from one side, and by distribution boxes 11 and 12 with bypass channels of analogues construction from other side. Bypass channels and distribution boxes are designed for distribution and direction of grain mixture flow by operating parts. Sections are covered with roof 1 from the top, and bottom plate 10 from the below. Inlet nozzles 5 are mounted on the roof for uniform grain mixture distribution to receiving frames, outlet nozzles 9 are mounted on the bottom plate and doors. From the sides sections are closed with coverings 2. Side channels 13 are formed by section guides with coverings from one side and longitudinal baffle of supporting frame from other side.


Balancing mechanism (fig.3) consists of shaft 15, upper and lower balancers 16 fixed on the shaft by clamps 11 and washers 12. Cabinet is placed under the upper balancer. Shaft rotates in the upper and lower bearing blocks. Upper bearing block consists of the housing 7, roller 4 and thrust 9 bearings, bushes 7 and two collars 13 and 14, and lower – consists of housing 5, roller bearing 4 and bush 6. Cups 1 are installed in the bearing 2 covers to retain grease and to prevent dust and dirt into the housing. Detachable weights 17 are placed on the balancing mechanism for adjustment of the sieve body oscillations amplitude. Rotating parts of the balancing mechanism are covered with protection constructions.


16 extension frames are installed in the guides of every section. Separator frame (fig.4) consists of all-metal tray 1 and wooden insertion frame 2. Insertion frame consists of wooden framework divided by internal baffles into six equal-sized cells. Sieve plate 5 is fixed on the top of the framework, welded support grid No.10-1 (item 3) – from below. Sieve plate cleaning is provided by moving cleaners 4, which are placed between sieve and grid – one in every cell of the frame. Cleaner is a triangular polyurethane plate with spherical stop lug in the center. Group of the 12 (twelve) upper frames in every separator section has a sieve with hole size 2,2х20 mm, group of 4 (four) lower (main) sieves – 1,7х20 mm. Sieve frames are installed in the cabinet in accordance with separator functional scheme (fig.6), windows in the frame for outlet of the product that passed through the sieve must be directed to the side of cabinet covering.


Receiving device (fig.5) consists of frame 1, two inlet boxes 2 and nozzles 4. Receiving device frame is welded from bent profiles. Plates with port-holes are provided under the inlet boxes. Brackets with port-holes are provided for receiving device fixation. Inlet boxes are designed for connection of gravity flow ducts and aspiration air ducts. Nozzles that serve for product intake are equipped with inspection windows 3.


Separator operational principle (fig.6) lies in the parallel and consequent movement of processing grain mixture along plane horizontal sieves, which perform uniform circular translation in horizontal plane. Process of grain mixture self-sorting is occurred due to sieves surface oscillations, as a result small grains (light fraction) and light impurities are concentrated in the lower layer, reach the sieve surface and pass through the sieve, while coarse fraction after consequent fourfold passing along 12 upper frames of every section is removed from the separator as a product that haven’t passed through the sieve. Small grain fraction and light impurities united into the common flow are supplied to the four lower frames through the side channels of every section. Small grain fraction that haven’t passed through the sieve and light impurities that passed through the sieve are separately removed from the machine.


Operating procedure


During plansifter operation process special attention should be payed to the following factors:


1) uniform loading of all sections;


2) tightness of the sieve body to prevent dusting in junctions;


3) contamination of one fraction to another;


4) state of all oscillating units and details, quit operation;


5) cleaning of sieves, checking the efficiency of cleaners during separator stops;


6) aspiration efficiency.


Radius of the uniform circular translational oscillations trajectory in horizontal plane of the separator is adjusted by removable weights fixed on the balancer.


During additional weights installation it is necessary to control their weight and position on the upper and lower balancers so they would be equal. Otherwise forces in the bearing assemblies are unfavorably distributed that disturbs horizontal movement of the body.


To determine the average radius of the sieve body circular vibrations, it is necessary to fix a sheet of millimeter paper or blank paper on the roof, hang the pencil with the help of device until it comes into contact with the sheet. Run the separator, and after reaching a steady state (after 10-20 min.) stop it. Measure with the ruler, accurate to 1mm, size of the largest and smallest diameters (D1 and D2) between end points of the trajectory trace left on the paper and determine the average oscillations radius by the formula: R=(D1+D2)/4 mm.