To prepare chocolate masses, a significant amount of cocoa butter is required. It is obtained by pressing cocoa liquor in hydropress plants. Solid residue
Technical characteristics of aggregates for molding chocolate products, formed after pressing and called cocoa cake, is processed into commercial (for sale in the retail chain) and production (for the preparation of confectionery masses and products) cocoa powder.
Gidropressovye installation. In the confectionery industry, hydropress plants are used, which consist of a hydraulic press (vertical or horizontal), a cocoa liquor dispenser, a high pressure hydraulic pump, and a control panel. Installations with a horizontal press are additionally equipped with devices for receiving and transporting cocoa cake.
A hydraulic press usually has 3, 6, 12, or 22 working chambers (bowls) arranged sequentially one above the other (vertical press) or one after the other (horizontal press). The working chamber is a cylinder closed at the ends by filtering elements, one of which can enter inside, creating pressure on the cocoa mass. The filter elements consist of a fine woven metal mesh resting on a drainage mesh with punch holes, which in turn rests on a grooved disk with holes. The presence of filters on both sides of the bowl creates favorable conditions for bilateral removal of cocoa butter from the working chamber.
The cycle of the hydraulic press installation consists of the following stages:
1) measuring the dose of cocoa liquor;
2) filling the cocoa working chambers with grated;
3) pressing, pressing cocoa butter;
4) removal of cocoa cake from process chambers;
5) the return of the working bodies to their original position, the "closure" of the press.
Installation (Fig. 6.18) works as follows. From a tempering collector 17, equipped with a steam jacket and a stirrer, cocoa liquor at a temperature of 90 ° C with a pump 16 is pumped through a pipe 15 to an intermediate metering tank 10. When the volume that corresponds to the capacity of the working chambers of the press is filled, the pump 16 will automatically shut off. Through the spool switch located in the control panel 13, the engine oil supplied under pressure from the hydraulic pump 14 is fed through a pipe 12 to the hydraulic cylinder 11 of the metering tank 10, inside of which there is a piston connected by a rod to the piston of the hydraulic cylinder. The piston of the dispensing tank squeezes the cocoa liquor into the telescopic pipe 9, from which through valve devices it enters the working chambers 8 of the press 5 (horizontal presses can have 3, 6, 12 and 22 working chambers, called bowls).
After filling cocoa with grated working chambers, engine oil from the spool dispenser is fed into the main hydraulic cylinder 1 of the press and pressing begins. The squeezed cocoa butter through the nozzles 6 is discharged from the filter elements and is collected in a common groove 7, from where it is discharged into the collection.
The end of pressing is determined in two ways. In the first case, the press is equipped with a graduated ruler 4, moving together with the main plunger of the press. Slider 2 is installed on the ruler, which at a given moment presses the limit switch, and the pressing cycle ends. The position of the slider on the ruler is determined during commissioning tests after each pressing cycle according to the average residual oil content of oilcake, which should be 17%. The second case involves the installation of a cocoa butter collector on an electric balance, which sends a signal to the control panel only after receiving a predetermined amount of oil. At the end of the pressing cycle, it is necessary to remove cocoa-cake from the working chambers of the press. For this, the presses are equipped with special hydraulic or mechanical devices. The removed cocoa cake falls on the conveying device 3 and is removed from the press.
Gidropressovaya a vertical press. The installation (Fig. 6.19) does not have an intermediate bladder tank and a transport device. From the tempering collector 16, cocoa liquor is pumped by a gear pump 15 through a steam-heated pipe 3 (steam is supplied through a pipe 2) directly into six working chambers 9 located one above the other. After full filling of the working chambers of the press, cocoa liquor will begin to flow into the collector through the return pipe 1.
11 hydraulic pump delivers pressurized engine oil for 17 highway in the dispenser control panel
Fig. 6. 19. Gidropressovaya a vertical 6-pot press
line 8 and from there through pipe 13 to the hydraulic cylinder of press 12. The engine oil is returned through pipe 18. The body of the hydraulic cylinder is connected to the base plate 10 by four columns 7. Working chambers and intermediate plungers with filter elements are located between them. Squeezed cocoa butter flows down the walls of the working chambers and through the funnel 14 is discharged into the collection.
To push the cake out of the working chambers, the press is equipped with a mechanical device 5, driven by an electric motor 6. In the ceiling above the press there are two holes 4 through which cables with a hook are inserted for easy disassembly of the press. Cocoa cake, released from the working chambers, is removed manually. The installation is controlled from the remote 8.
Fig. 6.20. Schematic diagram of a vertical hydraulic press unit.
The schematic diagram of the installation with a vertical semi-automatic hydraulic press is shown in Fig. 6.20. At the bottom of the press there is a hydraulic cylinder 31, which is usually installed on a foundation. The press is mounted on four steel columns 16, connected in the upper part by a traverse 15. A hollow plunger 23 is placed in the cylinder, which rises up under the pressure of the working fluid (engine oil) supplied to the cylinder through the fitting 32. The lower plate 25 with protruding upward punches.
In the punches there are vertical channels, and in the plate there is an annular channel for collecting oil. On the plates are installed coil springs 24, on the upper ends of which the lower bowl 20 is supported, fixed on the squeeze rods 22. The second plate 19 with the protruding punch is supported on the bowl. The springs 18 support the next upper bowl, also mounted on rods 22 (a press with two bowls is conventionally shown in the diagram; presses used in the confectionery industry have 6 bowls). The upper bowl abuts against the cross-beam 15. On the surface of the punch, the lower side of the plate 19, as well as on the cross-beam, filter elements 21 are fixed.
The filtering elements consist of a fine metal mesh, a mesh with punching holes and two grooved discs with holes with a diameter of 11 mm. All punches with filter elements enter the bowls and are their bottoms. Thus, the inner cavity of the cups is closed on all sides.
The rods 22 with their upper ends slide in the guide holes of the traverse, and the lower ends are fixed in the squeeze plate 26. The springs 23, which rest on the punch plate, the plate 26, and therefore the cups are always kept in the upper position. This plate is connected to the rods 27 of the pistons 29 moving in two hydraulic control cylinders 30. When the pistons move down, the rods lower the cups until their lower edge reaches the upper surface of the plate of punches 19 and 25.
The rods 27 have stuffing box seals 28, and the plunger has a lip seal 34.
The hydraulic press unit is equipped with a rolling pump 2 with a valve box. When rolling pin 1 moves up, the working fluid — engine oil — is sucked. When moving, the suction valve 7 rises and from the tank 9 into the valve box is sucked in the working fluid - engine oil. When the rolling pin moves down, the suction valve 7 lowers under oil pressure, the discharge valve 6 rises and the oil goes into the discharge line to the valve distributor 11. To eliminate pressure pulsation, the plants are equipped with three- or four-ring pumps.
In the distributor 11 there are valves 3 and 8, controlled by a handle 13. The valves are mounted on a common stem. If you move the stem to the left by rotating the handle, then valve 3 closes and valve 8 opens. When the rod moves to the left, valve 3 will be open, and valve 8 will be closed. To implement the stroke of the plunger 33 upward, valve 3 opens, and valve 8 closes. Oil pumped by the pump is then directed into the cylinder under the plunger. At the end
the pressing valve 3 closes and opens the valve 8. All the moving parts of the press together with the punch are lowered down. The oil is displaced from the cylinder 31 and enters the distributor, where it passes through the valve 8 and flows into the tank 9, equipped with a filter mesh. The distributor is equipped with a manometer 10 and a three-way valve 12 for supplying oil to the control cylinders 30.
The valve boxes of each rolling pin have limit pressure valves 5 with a spring regulator 4. Several valves are adjusted to a pressure sufficient to lift the moving parts of the press. When this pressure is reached, the valves 5 open and release the oil into the suction line. After that, part of the rolling pumps works "for themselves", without supplying oil to the cylinder of the hydraulic press. Other valves 5 are adjusted to the maximum pressure required for pressing.
In the diagram, the press is shown in the position before loading. The press works as follows: cocoa liquor is loaded from the tempering tank using a rotary pump into the press cups through the openings 17.
When the cups are full, the pressure in the pipeline rises and the pump stops using the membrane relay. At the same time, the lamps go out, which indicates the end of the bowl filling process. Each bowl is equipped with a valve box and a check valve, which prevents cocoa liquor from being squeezed back into the pipeline during the pressing process.
After filling the cups, turn on the pump 2 and open the valve 3 of the distributor. Engine oil is pumped into the press cylinder, and the plunger 33 rises. The punch of the lower plate 25 compresses the mass in the lower bowl and through it transfers pressure to the upper punches. The squeezed cocoa butter is collected in the annular grooves of the plates and from there flows into a special collection.
Upon reaching the maximum pressing pressure of about 45 MPa, the pressure limit valves 5 open, the oil supply to the press cylinder stops and the warning lamp lights up. By turning the distributor knob 13, the valves 3 and 8 are switched so that the oil displaced when the plunger is lowered from the press cylinder 31 enters the tank.
To push the cake out of the bowls, turn the three-way valve 12 of the distributor and supply oil to the control cylinders 30. The pistons 29 move down and, using the squeeze rods 22, lower the bowls down. In this case, the cake is pushed out of the bowls by the punches of plates 19 and 25.
The upper ends of the squeeze rods enter the yoke 15. By turning the crosspiece 14, the guide holes in the yoke can be closed so that the rods cannot pass through the yoke. This is done to ensure safe operation when removing the cake from the press. If the oil pressure in the control cylinders accidentally drops, the springs 23 will not be able to raise the bowl.
After removing the oilcake, stop the pump 2 and turn the three-way valve 12 to lower the oil from the control cylinders into the tank 9.
Pressing is carried out at a temperature of cocoa mass 90-96 ° C. To maintain the required temperature, the punches are equipped with steam heating.
Fig. 6.21. Hydraulic pump with horizontal movement of Rolling Pin.
Hydraulic presses are equipped with high-pressure hydraulic pumps, the value of which reaches 55-60 MPa. They work according to the mode, which is determined by the nature of the process pressed liquid phase. In general, the pressing process in hydropress plants can be divided into two periods. The first period is characterized by abundant squeezing of the liquid phase, for which it is necessary that the main plunger is quickly moved out of the hydraulic cylinder. In the second period, the particles, connecting with each other, form a framework, which, as the liquid phase is further pressed, increases the pressing resistance. The amount of squeezed liquid phase decreases and in this regard, the movement of the plunger slows down.
The hydraulic pumps used in the above installations can have 3, 4 and 5 rolling pins driven by a horizontal or vertical crankshaft; rolling pins can move in a vertical or horizontal plane.
In fig. Figure 6.21 shows a four-ring hydraulic pump with a horizontal crankshaft and horizontal rolling pins 6. Crankshaft 4 receives rotation from the electric motor / through V-belt drive 2 and pulley 3. Roller bearings 90 are mounted on four shaft elbows located at a 5 ° angle. The outer race is in contact with the rolling pin 6. Kinematic closure is achieved by spring 7.
The engine oil, filtered through the screen 21, enters the pump unit 8 through the suction valves 11, then through the discharge valves 9 through the pipe 12 - to the spool distribution device installed in the control panel of the hydraulic press unit. Through pipe 14, engine oil returns to the pump and is partially drained through pipe 17, and partially fed through line 16 to lubricate the crankshaft bearings. To remove air from the valve space, plugs 10 are used, and permanent round magnets 22 trap metal chips from the oil.
In the first pressing period, all the rolling pin of the pump works, providing maximum performance. In the second period, two of 13 electromagnets are disconnected. The thrusts 15 previously raised with the loads 18 are lowered, turning the rocker 19. It moves up the rod 20, which lifts the suction valve 11 and prevents it from sitting in the socket when the rolling pin moves to discharge. The engine oil is pushed through the slot back into the pump tank, and not fed into the discharge pipe 12. The hydraulic pump performance decreases, as a result of which the movement of the main press plunger slows down. Magnets can be switched off with or without stopping the hydraulic pump. When the hydraulic pump stops, this operation leads to a stepwise change in the operating mode of the installation, which is undesirable, since a significant pressure drop in the hydraulic system occurs, loss, time for pressing.
In comparison with the vertical, horizontal presses have several advantages: better performance and a higher yield of cocoa butter, the full automation control and management, enabling a single operator to serve several presses. In addition, the floor 1 m2 load them a widow less.
Press productivity (in kg / h) for cocoa mass is determined by the formula
P = 60mG / t, (VI .3)
where m is the number of working bowls; G is the amount of cocoa mass in one bowl, kg; t is the duration of the pressing cycle, min
The most widespread at confectionery factories are installations with horizontal hydraulic presses of the ROU type (Italy), 1450 (GDR), as well as presses of the SRN-12 type (FRG).
Equipment for the production of cocoa powder. The cocoa cake obtained after pressing before crushing must be cooled to a temperature of 30–35 ° C, otherwise, during grinding, molten cocoa butter will be released, which will smear the working bodies of the grinding equipment.
Grinding of cocoa cake is carried out in two stages - rough, preliminary, using gear mills and fine, final, using units equipped with a hammer or pin grinder and devices for mechanical, air or combined (mechanical and air) separation of cocoa powder.
3 at about in and to to and I mill 95/1 with one pair of rolls. Mill rolls (Fig. VI.22) rotate at the same speed. The cake block is loaded into the small piece through a slit 8, which is bounded below by an inclined surface 7, and above by a guarding grid 9. The cake is captured by the protruding teeth 2 of the rotating rolls 6 and 11. The rolls
|Technical characteristics of installations gidropressovyh|
Performance on the press cocoa butter, kg / h
Total capacity bowls kg
The number of press cycles per hour limit oil pressure in the hydraulic system, MPa bowl inner diameter, mm
Overall dimensions, mm Weight, kg
Consumption of steam pressure 0,15 MPa, kg / h
X X Х2000Х 2860 3570 12 500 40X
6500 2200 1500 X X Х27Х 000 100
7650 X Х2400Х Х3300 22 000 80
7180Х X X 1400Х 2130 32 000 120
|The pump of the hydraulic system|
Productivity, l / min Rolling Pin Number of water consumption, l / h Electric motor power in kW
Overall dimensions, mm Weight, kg
1450Х X 760X710 680
1950Х X 700X1100 1000
1450Х X 760X710 680
UBR 1/30 9-18
1080Х X 943X1720 1050
recruited from the disc mounted on the shaft and the 3 12. Disks connected with three ties 4. 6 drive roller carried by a gear motor through the gears 15 16 and 14. The upper roller is 11 from the bottom via a gear to
And - 1. Cake, falling into the gap between the rolls, crushed teeth spilling into pieces of irregular size. Chunks
Fig. 6.22. 95 / 1 teethed mill
fall down and fall into the auger 1, which removes them from the mill. The screw is driven by an electric motor gear chain drive 15 17.
During operation of the mill, the optimal clearance between the rolls is established by moving the upper roll 11 using the adjusting device 10. Before starting the crusher, check the position and reliability of the fastening of the combs 5 and 13, which serve to clean the space between the teeth of the disks.
The designers of the “Red October” confectionery factory developed a gear mill with two pairs of rolls.
Factories used mill supplied from the GDR (types 95NY and 95 / 1) and Italy (type of IOR-1).
Grinding unit for cocoa powder with air separation of the Schönenberger system (Switzerland). Schönenberger unit can easily be used in production lines. The factories combine this unit with a pneumatic system that feeds cocoa powder to filling machines (Fig. 6.23).
The unit consists of a shock-pin mills, tubular cooler 6, 7 and 8 separator cyclone.
The cocoa cake, pre-crushed in a gear mill to the size of a nut, is loaded into the silo 1 of the elevator 2, which transfers it to the silo 3. Having passed magnetic protection 4, the oil passes through an electric batch dispenser and enters the impact-pin crusher 5.
The grinding mechanism of the crusher consists of two disks facing each other with their ends. One of them is fixed motionless, the other rotates at a frequency of 5550 rpm. At the ends of both disks, six concentric rows mounted 540 cylindrical pins with a diameter of 10 and a length of 55 mm. The pins are placed so that in the radial direction there are several channels that facilitate the passage of the crushed product. In these places, the holes in the disks are closed 71 with a short dummy pin. After the pins wear, the discs are removed and the pins are replaced with new ones. The pins are made of high quality alloy steel grade 12X2NZMA.
The mill body and hinged lid are equipped with water jackets in which cooling water circulates at a temperature of 25-30 ° C.
The crushed cake is picked up by a stream of air and passes through a tubular cooler 6. After cooling, the powder is separated from large particles in the separator 7 and goes into cyclone 8. In the cyclone, the powder settles and is transferred to the material pipeline of the pneumatic conveying system with a lock gate 9.
The tube cooler is made in the form of series-connected horizontal pipes with an inner diameter of 180 mm, equipped with cooling jackets, in which an 11% solution of calcium chloride circulates with a temperature of FROM -4 TO + 1 ° С. ;
|The basic specifications of mills for crushing cocoa cake|
|Productivity t / h||
0,6 – 1,0
|Electric motor powerin kW||2,0||1,1||5,5||7,0|
|Overall dimensions, mm|
The air released from the powder in the cyclone is sucked in by the fan 10 and fed back to the mill 5. Large particles separated in the separator 7 pass through the hopper, are picked up by the air coming from the fan 10, and returned to the mill for regrinding.
From the gateway shutter 9 finished powder sent to the cyclone 11, where he was going, and then rotary valve 13 14 transmitted through the pipe to screw 15, distributing it
Fig. 6.23. Schoenenberger grinding system with air separation
for Packaging machines. The air is cleaned in the cyclone 12, 16 sucked fan and returns to lock shutter 9.
The whole system works under vacuum, so there is no dust formation during unit operation and the loss of cocoa powder is minimal. The unit receives high quality powder with good color.
When grinding and friction on the surface of the transporting pipes, the particles acquire an electric charge, causing them to stick to the walls of the apparatus. The pipes are equipped with devices for continuous tapping and shaking off particles.
The Schoenenberger company produces units of six grades with a capacity of 200 to 1250 kg / h.
A similar besitovy disintegrator unit 1RS-1000 is produced by the Italian company Carle and Montanari.
|Technical characteristics Shёnenbergera system unit|
|Productivity, kg / h||900|
|The length of the cooling section, m||10|
|Air velocity in materialoprovode, m / s||25|
|The concentration of the mixture of air and powder in materialoprovodah kg / kg||0,35|
|Electric motor power, kW||88,5|
|Overall dimensions, mm||1500X3800X4150|
|Weight, kg||13 000|
The Heidenau Plant (GDR) produces a 641-A type besiegit unit, the main devices of which are a turbine mill and two vertical cooling columns with spiral mixers and water jackets with circulating cooled brine. Cocoa powder moves inside the column from the bottom up under the influence of air flow and is mixed with a mixer. The separation of powder from air is carried out in air cyclones.
The basic specifications of the grinding units 1RS-1000 and 641-A
|Productivity (in kg / h) when the fat content in the cake,%|
|Electric motor power, kW|
|Overall dimensions, mm|
Cocoa powder made on a particular machine is usually packaged on cocoa filling machines, the description of which is given in chapter X.