The presses differ in the design of the dispensers, the number of chambers in the kneading machine and their location, the number of pressing screws, the design of the pressing heads, the shape of the dies and the place of evacuation.
The main types of dispensers: flour - screw, belt and rotor; waters - rotor, piston and rotor-scoop.
Depending on the duration of the kneading and the place of evacuation, the dough mixers of the presses can have one, two or three successively installed chambers.
Depending on their performance, one, two or four pressing augers can be installed in presses, and depending on the destination, a tube can be installed (for rectangular dies) or a head (for round dies).
Press LPL-2M. The scheme of the pasta press LPL-2М is shown in Fig. 4.1. The press consists of the following main components: a dosing device, a kneading machine, a drive unit, a pressing body, a pressing head, a blowing unit
Fig. 4.1. Pasta press layout LPL-2M
roevstva and piping systems, cutting mechanism. All of the above mechanisms are fixed on the press frame, which is a welded frame on four supports, to which is also attached a platform with railings and a ladder for servicing the press. With a press the vacuum system is completed.
The dosing device is located above the kneading machine and includes a screw flour metering device, a scoop water metering unit and a special drive unit.
The screw feeder has a cylindrical 1 body with an 4 feed hopper and 2 guide pan for entry
flour in a kneading machine. Inside the case, a single-cage water dispenser is installed, which is a 10 tank, inside of which an impeller with 11 pockets rotates on a hollow shaft. When the impeller rotates, each pocket receives a certain amount of water, which, when it is rotated, overflows through the longitudinal holes of the 12 hollow shaft and drains into the compartment of the 14 tank. From here, water is diverted through the 13 pipe to the press dough mixer.
Special drive unit operates as follows. The rotation of the drive from the 5 electric motor is transmitted via a V-belt transmission to the input shaft of the worm gearbox, which has two output shafts, one of which (hollow) imparts a continuous rotational motion to the water metering rotor. The second shaft is fitted with a 6 ratchet wheel. On the worm wheel, two double-arm 8 levers are attached to the axles, one lever arm is pressed against the spring and engages with the ratchet wheel, there is a roller at the end of the second shoulder. The angle of rotation of the metering screw is adjusted by the 7 handle connected to the 9 half ring. When the rollers move along the inner forming body of the worm gearbox, the arms of the arms engage with the ratchet wheel and turn the screw shaft. When the rollers are rolled on the half-ring, the arms of the arms break out of the ratchet wheel and the auger does not rotate. The frequency of the flour metering screw auger is adjustable within 0 ... 24 min-1.
The rotational speed of the water metering shaft is 36 min-1. The amount of water entering the mixing machine depends on its level in the tank. The level control is made in the form of a hollow cylinder with a hole in the side. When turning the cylinder, the hole is located at a certain level, which is the water level in the tank. Excess water through the hole in the cylinder enters the drain.
The kneading machine is a single-chamber 15 tank with a length of 1500 mm made of stainless steel sheet. Inside are installed: 77 shaft with a diameter of 60 mm with working elements fixed on it in a certain sequence, 21 knife for cleaning the end wall of the chamber from sticking dough; eleven 18 fingers and five 16 paddles to provide the necessary level of dough in the chamber, its processing and movement within the chamber; 24 pusher to ensure dough entry into the press case.
The blades on the shaft of the kneading machine are set at a certain angle, which is selected during the start of the press. The optimum angle of inclination of the plane of the first two blades (depending on the filling of the trough) to the axis of the shaft is 60 °, the following - 40 °
The amount of dough coming from the kneading chamber into the press case is adjusted using the 25 damper, which is moved using the screw with the 26 handwheel.
The kneading machine is closed with a 19 lattice cover interlocked with the machine shaft cam clutch. The lid can be opened only after switching off the drive motor or disconnecting the coupling.
The rotation of the shaft of the kneading machine is carried out by the 20 electric motor with a rotational speed of 1450 min-1, V-belt transmission, three-stage spur gear. The kneader of the kneading machine is connected to the shaft of the gearbox of the main drive with a 22 clutch with a lock. The clutch consists of gears, half-couplings and a lever with a rod and a retainer (not shown in the diagram). The gears are connected by a double-row chain with a pitch of 19,05 mm. Shaft speed 82 min-1.
The 27 pressing body is a cylindrical tube with two flanges at the ends. With one flange, the housing is attached to the gearbox of the main drive, the other - to the pressing head. Inside the case, there is a single-thread 28 pressing screw with a length of 1400 mm, diameter 120 mm, with a step of 100 mm with a three-way link 32 at the end. In the middle part of the auger there is a gap in the screw blade, in which the 29 washer is built in, which allows the dough to move along the 30 overflow channel, from which air is sucked from the passing dough through a vacuum valve using a vacuum pump.
33 grooves are axially located on the inner surface of the pressing body along its entire length, reducing the test turning during the auger rotation with a frequency of 41 min-1. A welded water jacket 31 is installed in the outlet part of the pressing housing, through which tap water circulates to cool the pressing housing.
The 36 pressing head is designed to install one round 37 matrix and is a cast dome-shaped structure (internal volume up to 6 dm3). At the top end of the head there is a hole closed by a 34 flange. The hole serves to extract the auger from the pressing body without removing the head. 35 gauge is mounted on the head to control
The 38 pod device serves to pre-dry the pasta coming out of the spinnerets of the die's forming holes. The device consists of a centrifugal fan with an electric motor of power 0,8 kW and rotational speed 2830 min.-1, an obduvochny ring with openings with a diameter of 8 mm for air passage on its internal part. The holes are located in seven rows in height. The distance between the holes in height 13,3 mm, horizontally 40 mm. Blow ring set under the matrix. Depending on the speed of pressing, the duration of finding the products in the blasting zone with the overhead cutting method 5 ... 6 During this time, a dried crust has time to form on the surface of the product, which prevents the gluing of pasta during its further cutting or transportation. The piping system is designed for the supply and discharge of hot and cold water, as well as the connection of the pressing body with a vacuum pump.
The vacuum system of the LPL-2M press (fig. 4.2), designed to remove air from the test mass and obtain its dense consistency, consists of the VVN-1,5 two-section water-filled vacuum pump, the piping system and the vacuum valve
Fig. 4.2. Vacuum press system LPL-2M.
on, mounted on the press housing. The main components of the vacuum pump are the cylindrical housing (stator) 2, the water-separator (receiver) 4, the electric motor driving the pump 18
The stator is a cast-iron cylindrical body, at the ends of which there are loboviny - suction and injection. An 20 pipe, lowered into the water collection tank and intended to supply water to the pump, is connected to the lower part of the suction head. In the upper part of the lobovina are located the suction inlet and check valve 3. An 17 pipeline is connected to the delivery head for discharging a mixture of water and air from the pump. At the top of the exhaust pipe is a 15 funnel with a tap for filling the case with water before starting work.
The vacuum pump, electric motor and water collection tank are installed on the foundation or metal frame so that cold water can be fed into the tank, and the heated water can be discharged into the 7 sewer pipe. The vacuum valve is connected to the vacuum pump via the 6 pipeline.
Before starting the vacuum system, tap water is poured into the water collection tank to such a level that the drain pipe is slightly below the water level in the tank. Then, water is poured into the pump housing through the funnel to the level of the rotor shaft axis and the 16 valve is closed.
After filling the dough with a screw body, turn on the vacuum pump drive and close the 5 valve. Through 4 ... 5 with after turning it on gradually open. The vacuum valve is installed in the pressure housing above the bypass channel. Inside the case of the 11 vacuum valve, there is a 7 pin with a diameter of 25 mm for cleaning the turns of the 8 screw from sticking dough. The clearance between the pin and the outer surface of the auger is adjusted using the 12 knob, the bias spring and the 10 union nut. For visual observation of the operation of the vacuum valve in its end part there is a viewing window 13, covered with glass. In the side part of the housing there is a fitting 14 for connecting a vacuum pump, on the opposite side - a fitting 9 for connecting a vacuum gauge.
Work pasta press as follows. Flour from the bunker by gravity continuously flows into the dosing unit, from which it is fed by a rotating screw into the trough of the kneading machine. At the same time water temperature
60 ° C from the dispenser through the pipe enters the place of the kneading machine, where the flour is fed. Water consumption for the preparation of dough, depending on the moisture content of the flour is 80 ... 90 l / h, for cooling the pressing body - 110 l / h. During normal operation of the press, the dough should fill the 2 / 3 with the capacity of the trough and have a slight slope towards the outlet.
The required level of filling the trough with dough is achieved by adjusting the inclination of the plane of the ends of the blades to the axis of the shaft, which throw a certain part of the lumps of dough in the direction from the outlet to the dosing units. Dropping lumps of dough of optimal size in the opposite direction is necessary to ensure the normal circulation of the dough, which increases the duration of its stay in the trough to 10 minutes, contributes to the swelling of gluten and better dough processing
Mixed in the form of lumps and grains, the pasty mass from the trough of the kneading machine goes through the hole in its lower part into the pressing body. At the same time, by adjusting the gate size of the outlet, you can change the amount of dough supplied to the pressing body, and thereby change the performance of the press.
In the pressing case, the dough, moving, flows around the washer on the auger and enters the bypass channel, which is located in the central part of the pressing case. Air is removed from the bypass through a vacuum valve. The residual air pressure in the pressure housing is 10 ... 20 kPa. Next, the dough continues to move along the pressing body, is captured by the turns of the screw, is injected into the head and then pressed through the forming hole of the die.