Plansifter RK-2 and RK-4 is designed in accordance with Technical Regulations in Ukraine TU U 14311353.002-98 for cereals sorting (cleaning from impurities, fractionation before hulling, selection of intermediate hulling and peeling products, sorting and products control) at cereals industry enterprises.

Specifications RK-4

3) nominal size of sieve frames, mm – 400õ800

4) total rated active sieves area, m2 – 13,5

5) body oscillations frequency, ñ-1 (rpm), deviation max.0,17 ñ-1 (10 rpm) – 3,0; 3,2; 3,7; 3,8; (180; 190; 220; 230)

6) radius of the body circular oscillations, mm – 28-22

7) air consumption for aspiration, m3/h – 840-1080

8) aerodynamic resistance Pa (mm w.g.) – 150-200 (15-20)

9) electric motor power, kW – 3,0

10) overall dimensions, mm, max.

               length – 2310

               width – 1390

               height to the feed board – 2370

11) weight, kg: gross weight – 2417,

                        net weight – 2415.

Plansifter is produced in 10 versions that differ by functional schemes of sections, which arrangement is shown on fig.1.2.

Specifications RK-2

1) plansifter technical capacity

2) quantity of product inputs (sections) - 2

3) nominal size of sieve frames, mm – 400õ800

4) total rated active sieves area, m2 – 6,75

5) body oscillations frequency, ñ-1 (rpm), deviation max. 0,17 ñ-1 (10 rpm) – 3,0; 3,2; 3,7; 3,8; (180; 190; 220; 230)

6) radius of the body circular oscillations, mm – 28-22

7) air consumption for aspiration, m3/h – 420-540

8) aerodynamic resistance Pa (mm w.g.) – 150-200 (15-20)

9) electric motor power, kW – 3,0

10) overall dimensions, mm, max.

            length – 1920

            width – 1100

            height to the feed board – 2500

11) weight, kg: gross weight – 1810,

                        net weight – 1809.

Structure and Functioning

Plansifter is represented by modular cabinet construction with sliding sieve frames and consists of sieve body 9 (fig.1.4.1), supporting frame 21, balancing mechanism 6 and drive 3. Plansifter is suspended on steel ropes to suspensions 1 fixed on the ceiling frame. Body is divided into four sections by supporting frame baffles. Fifteen sieve frames 24 with trays 25 and collector* (*collector – frame 6 in the scheme 3) are installed in the section 23 guides. Body exterior coats and sections guides form side bypass channels. Sections doors are equipped with double walls, which form bypass channels from the receiving side. On the opposite side, sections bypass channels are made in the form of removable distribution boxes attached to the sections rear pillars. Sieves are cleaned by rubber balls 27.

Inlet nozzles (feeders) 5 with guides, which allow uniformly divide initial product to inlet sieve frames of every section, are installed on the body. Inlet sleeves 16 are mounted to the nozzles 5 and receiving devices nozzles. Outlet sleeves 11 are mounted to nozzles 17 and 30, fixed on the body bottom, and to floor nozzles 12. Receiving boxes 2 are fixed on the receiving devices, which are suspended to the ceiling frame by holders 13 and rods 14. Air ducts, aspiration systems and gravity flow ducts for product supply are fixed on the receiving boxes. Supporting frame 21 is represented by integrally mechanical welded construction. Sections, side coating, bottom and ceiling are fixed on the supporting frame. Upper and lower bearing blocks of balancing mechanism 6, which sets plansifter in motion, are also fixed on the supporting frame.

Sieve frame (fig.1.4.2) is made of wooden bars. Frame is divided by bars into 4 cells. Boxes 2, which bottom is made like a sieve plate, are installed in frame cells. Box sidewalls do not have holes and serve to protect frame wooden parts against wear by cleaners. Cleaners, balls Ø 25 mm, are designed for sieves cleaning, and two cleaners are putted into each cell before fastening the sieves at groats mills. Sieve frames are accomplished in two versions: single and double-sided. In single-sided frames product that passed through the sieve is transferred only one way (to the one side channel); in double-sided – to the both sides.

Tray is a sheet with bent ends on the short side and two angle elements attached from below, which serve to fix the tray in the sieve body section, to remove tray with frame from the section and to provide it necessary stiffness. Pile cloth pads are glued on longitudinal bars of the sieve frame to prevent mixing of separate product fractions, and to provide free movement of frames along sections guides. Flannelette pads are glued between frame and tray and on the middle bars.

Arrangement of balancing mechanism is shown on fig.1.4.3. Mechanism allows adjusting radius of the plansifter circular oscillations by changing balancer weight due to installation or removal of removable loads 2 and 3. Speed of the balancing mechanism is adjusted by removable pulleys on the electric motor of plansifter drive (see tab.2.2).

Plansifter body is driven by V-belt transmission from electric motor. Drive motor is installed on the bracket fixed on the cabinet. Belts tension is accomplished by moving the motor through plate slots with the help of tension bolts. Plansifter kinematic scheme is shown on fig.1.4.4.

Floor nozzles serve to receive separated product fractions from the plansifter body. Construction of nozzles blocks is shown on fig.1.4.5. Upper nozzles 1 are connected by fabric sleeves with body nozzles; lower nozzles have flanged edge for connection of gravity flow ducts by standard yoke clamps. There is an access hole closed with plug 2 on the upper nozzle, which serves for sampling. The base of nozzles is box 3, which after plansifter installation is poured with concrete. Holes in the box sides are designed for easy installation of nozzles.

Plansifter is driven by motor ÀÈÐ 112ÌÂ6ÓÇ with power 3 kW, oscillations frequency 950 rpm.  Electric motor must be powered by three-phase AC mains with frequency 50±1 Hz, voltage 380 V. Plansifter electric scheme (fig.1.4.6) provides motor switching on and off, protection of the motor and electrical wiring against short-circuit currents, overload, rated voltage. KM starter, which connects motor to the power network with its contacts, is self-locking and triggers by pushing the button S B2. Stop the electric motor by pushing the button S Â.1.

Operational principle of plansifter lies in the parallel and consequent product sifting through plane horizontal sieves, which perform circular translation. Sorting process (fig.1.4.1) starts when product is supplied to sieves through receiving boxes 2 and receiving nozzles 5. Product movement inside cabinet construction is carried out in accordance with one of technological process schemes (fig.1.4.7) and depends on plansifter version.  

Product use

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

- uniform loading of all sections;

- tightness of the body to prevent dusting in junctions;

- contamination of one fraction to another;

- state of all oscillating units and details, quit operation;

- cleaning of sieves;

- aspiration efficiency, preventing steaming of the walls inside the body at an ambient temperature below 15°C.

Efficiency of separation processes and extraction coefficient of fractions that passed through screen depends on initial product qualities, load and may be adjusted by regulation of plansifter kinematic parameters – frequency and body oscillations radius. Setting an optimal kinematic mode of the plansifter should be aimed to succeed the best technological effect. Optimal kinematic mode of the plansifter is specified in tab.2 depending on initial product and technological process system. Plansifter amplitude of circular oscillations is adjusted by removable loads fixed on the balancer (fig.1.4.3). Dependence between body circular oscillations radius (1/2 of amplitude) and removable loads weight is specified in tab.2.1. Quantity of additional loads, which must be fixed on balancers, depends on the radius according to fig.2.3 and tab.2.1.

Table 2

During additional loads installation their weight and configuration on upper and lower balancers must be equal. In case of failure to do so, loads in bearing blocks are unfavorably distributed that breaks body or sieve frames horizontal movement and deteriorates effect of product separation. Required oscillations frequency of the plansifter is set by selection of electric motor replacement pulley in accordance with data specified in the table 2.2.

Body oscillations radius is determined as follows. Fix clean paper sheet on the free area of the body roof. Touch the sheet with a sharped pencil, which must be fixed in special holder or holding it motionless in an outstretched hand. Pencil leaves a trace on the paper – the trajectory of the plansifter oscillation, which is close to the circle. Measure the largest D1 and the smallest D2 distance between two opposite points of the circle and determine the average radius R by the following formula:

R = (D1+D2)/4

If it is necessary to reequip one or more sections from one functional scheme to another, customer can optionally receive necessary sets of replacement parts and, by its own resources and means, change plansifter to the desired version.

Appointment of replacement parts group sets:

Set ¹1 – for modification of section scheme 1 to scheme 2;

Set ¹2 – for modification of section scheme 1 to scheme 4;

Set ¹3 – for modification of section scheme 2 to scheme 1;

Set ¹4 – for modification of section scheme 2 to scheme 4;

Set ¹5 – for modification of section scheme 4 to scheme 1;

Set ¹6 – for modification of section scheme 4 to scheme 2.

Each set contains replacement parts for one plansifter section.

List of replacement parts group sets is specified in appendix.

Readjustment of the plansifter sections from one functional scheme to another should be carried out in the following sequence:

- remove corresponding bypass boxes or sheets with windows in door and cabinet sections, unscrew the fixing screws and replace them by necessary boxes and sheets with windows from the set of replacement parts. While replacing boxes and sheets, it is necessary to check carefully the absence of gaps in the joints of neighboring elements;

- fix the seal with glue 88-ÍÏ in accordance with Technical Standard of Ukraine ÒÓ 38-105.540;

- unscrew the nuts and remove guides, which must be replaced, remove or reinstall intermediate bottoms;

- to change movement direction of fractions that passed through sieve from single-sided trays of sieve frames it is necessary to remove the tray with frame and turn it to 180˚.