Lines are a set of unified equipment installed in the order of the technological process and connected together by vehicles. At the enterprises of the sector, the production of pasta is carried out mainly on automated lines, which by their function are divided into lines for the production of long and short pasta.
LMG line for the production of long pasta. The composition of the line includes (Fig. 7.11) LHG / 1 flour and water dispensers, LPSH-1000 screw press, self-weighing, pre-drying and final drying dryers, stabilizer storage, cutting and cutting machine with pneumatic scrap, Electrical equipment, automatic process control system.
Flour and water with the 13 dispenser are continuously and evenly dosed into the 14 three-chamber kneading machine. If necessary, additional enrichment agents are additionally introduced. In the chambers of the kneading machine, kneading and evacuation of the dough takes place, then it is molded using the screw 15 through the 12 tube matrixes. Macaroni strands 10, emerging from the matrices, are separated by 11 blower 9 into two equal streams and freely pass into the slot between the movable and stationary cutting blades 8. After the strands of pasta fall below the bastoons on 600 ... 650 mm, they are cut off by knives from the main stream, are hung at the same time for two 17 bastoons, then trimmed with undercut 6 and trimming 3 knives. At the same time, the self-testing cycle is established. With a correctly selected cycle, the strands on the bastoon are the same length, and the number of raw cuttings is minimal.
Appearing when cutting macaroni cuts with 4 screws through the 5 conduit, compressed air is sent to the first chamber of the kneading machine.
From self-weighting, bastoons with products are transferred to the lower 2 tier of the preliminary two-zone three-tier dryer 16. When entering the dryer, the bastum presses its weight on the end switch lever, which turns on the dryer drive and moves it one step at a time with the help of combs and chain conveyors. Upon receipt of the next bastoon, the cycle repeats itself. So the bastenders with the products pass all three tiers of the dryer. From the top layer of the 18 pre-dryer, the bastenders with the products are sent to the first (upper) 20 tier 19 dryer for final drying, where the products on the bastenders pass five tiers, with four drying and lapping zones alternating on each tier.
Fig. 7.11. Scheme of the line for the production of long pasta with drying on bastoons
The duration of the products in the dryer for pre-drying is 15%, for the final - 85% of the total duration of drying of pasta.
From the fifth (lower) level 1, dryers for final drying of the bastoon with products through the intermediate zone 21 are transferred to the 24 stages of the stabilizer storage 23.
For this purpose, the drive management mechanism selects an unloaded stage to receive the bastons and activates the drive of the selected tier.
The 22 chain hoists are taken one by one to an unloaded stage and, when driving, press their weight on the limit switch that turns on the drive motor of this stage. The electric motor works until the first strike does not come off the limit switch lever. Then comes the second striker and just like the first one turns on the electric motor, etc. The completion of the tier is determined by the ring signal. Upon a call signal, the operator switches to the next tier.
At the end of the tier, the bastoons, moving along the rails, fall on the bevel and, falling, push the levers of the limit switches. The limit switches are activated, including the drive of the lowering device. The conveyor of the 25 lowering device delivers the bastorns to the 26 machine receiving device for removal and cutting. Bastuj, going from the conveyor to the receiving device, presses the levers of the limit switches, which include the drive of the pick-up and cutting machine. The bastoon is picked up by the removal conveyor, freed from strands, and sent to the return conveyor of 7 bastoons by a chain conveyor.
The mechanism of return of the bastoons consists of a chain conveyor of length 66000 m, drive and chain tensioning mechanism. The conveyor is located along the bottom of the line and represents two parallel chain contours on which two rolls are fixed on 12 chain links on both sides on axes. Internal rollers with a diameter of 20 mm together with the chain are moved along the guides of a special profile, in the upper part of which there is a synthetic round cord. The upper part of the cord protrudes above the surface of the guide on 1 ... 1,5 mm, so that the bastons with their trunks rest on it. External rollers with a diameter of 36 mm protrude above the cord on 2 ... 3 mm. When the chain moves, the outer rollers rest against the trunnions of the bastons and move it along the guiding surface of the cord until it rests against the previous strike. When the bastenders are approaching self-calibration, the vertical conveyor of the lifting of the bastons removes them from the chain return conveyor and feeds it into the self-weighing device.
The conveyor is driven (speed 0,033 m / s) from the individual drive installed before self-weighing. The chain tensioning mechanism is mounted at the end of the line opposite the node.
Line for the production of short pasta with conveyor dryers. The automated line of AKOR (Russia) (Fig. 7.12) includes a flour feeding system, a press, a vibration drier, three bucket elevators, a drying chamber unit (SBK), combining two zones for preliminary and final drying, a cooler, a stabilizer storage tank And the automatic control system for drying
Flour through the cyclone-discharger 8, water and, if necessary, various concentrating additives with the help of batchers continuously and evenly dosed into a two-chamber kneading machine 9 press, where kneading and evacuation of the dough occur. The mixed dough is pushed by two pressing screws 7 into the pressing heads. Knives 4, rotating on the plane of the matrix 6, cut off from the total test flow necessary for the length (shape) of the product, which are then blown by the airflow from the centrifugal fan 5. The raw pasta is sent to the 3 vibrating desiccant, where the product passes down the five vibrating 2 sieves, is blown out by 1 axial fans and dried. The products from the vibration drier using the first (ring bucket) elevator 10 with the tilting device 20 are transported to the 77 spreader (vibrator), which distributes the product throughout the entire upper deck 12 13 dryer for uniform pre-drying.
In the first zone of the BSK product for 45 ... 55 min passes from top to bottom five belt conveyors, dries and loses 6 ... 7% of moisture. Further, the products are moved down the nine conveyor belts of the BSC to the second zone for final drying, where they disappear for 4 ... 5 h to the standard moisture. Then, in order to reach the standard temperature, the products for 4 ... 5 min are blown by the axial fans 7 on the 14 75 shaker. With the help of the second (Z-shaped) elevator 16 the dried pasta is sent to the hoppers 77 of the stabilizer. This is also the product produced during one, two shifts. Packaging of the products is carried out in the day shift, for this the product from the silos with the help of 18 belt conveyor and the third elevator 19 is directed to the filling machines.
Line for the production of short pasta with drum dryers. The composition of the automated line (Figure 7.13) includes dispensers for flour and water, press, vibration drying, four serially installed drum dryers, a vibratory cooler.
Fig. 7.12. Scheme of the line for the production of short products with conveyor driers
Fig. 7.13. Scheme of the line for the production of short pasta with drum dryers
The press has a preliminary kneading machine 7 with intensive mixing of components in the centrifugal force field, created by a kneading shaft with blades at a speed of 530 min-1, a kneading machine with two 8 and 9 consecutive chambers for final kneading. A distinctive feature of this kneading machine is the complex motion of kneading shafts, which, in addition to axial rotation with a frequency of 60 min-1, perform reciprocating motion along the first chamber with a stroke frequency of 12 with an amplitude of 60 mm. This achieves better testing of the dough and continuous cleaning of the inner surface of the first chamber with blades from the adhering dough. Vacuum treatment of the test is carried out in the second chamber, from which it is guided by two screws 6 to the forming matrix 5.
The molded products are cut using 4 rotary knives, air blown from 3 centrifugal fans, and sent to 2 vibrating dryer in two streams, in which five vibrating screens pass from top to bottom, whilst being intensively blown by 7 axial fans.
Pre-dried products from the two vibrating trays enter the first drying drum. For this, two 21 loading windows with dimensions of 300x400 mm are provided in the end face of the drying tunnel. Vibrating trays are installed on flexible vertical supports on the floor of the room.
To ensure the necessary technological regimes of the drying process, all four successively mounted drums are closed with 11 heat-insulating panels. Between the top overlap and 16 drum dryers there are 14 axial fans and 12 radiator batteries. Each dryer has six axial fans with an output of 1,1 kW each and one centrifugal suction fan 10 with an output of 0,37 kW
The intake of fresh air into the dryer and discharge of the waste are automatically adjusted in predetermined ratios. To do this, in the upper overlapping above each dryer there are three openings for fresh air, each of which is blocked by 13 gate valves using a traction and gear system.
To prevent the cooling of the products at the time of their overload, coils are installed in the end parts of the drums at the discharge points of the product, hot water circulates through them, and heaters under each 15 tray. Each drying drum is installed on four 20 rollers, which allow it to rotate at different frequencies. In this case, the speed of the reels is set depending on the duration of drying of the product.
Dried products from the last drum through the 17 tray are routed to the 18 vibratory cooler, which has a horizontally mounted perforated tray 19. During the movement of products on the vibrating surface of the tray, they are blown by the shop air from the axial fan 22. Chilled products by various transport devices are sent to storage silos or to filling machines.
Safe methods of working on production lines. Each of the production lines is a complex of machines requiring highly qualified service personnel.
The line is allowed to persons who have passed the relevant training and passed the exam with a mandatory mark
On working machines, lines are forbidden to repair and lubricate, remove fences, shrouds and other parts, touch moving parts. Cleaning, repair, preventive inspection of the mechanisms of the lines is carried out only when they are completely stopped. At the same time warning signs are posted on the launchers: "Do not include, people are working!".
Before starting each line machine, make sure that no repairs, lubrication of the machine and no foreign objects are made.
In order to prevent an accident from exceeding the pressing pressure, the pressing body of the press has an automatic locking mechanism with the drive of the pressing screw. When the press screw stops, an audible signal sounds. In the event of failure of the lock in the pressing body, a special plug with a safety pin is provided, designed to operate at a pressure of more than 16 MPa.
The blocking of the covers of the kneading machines must be kept in good order. A platform and a ladder on the press
Must be clean and serviceable. It is forbidden to clean the press on the move and open the covers of the dough-mixing machines. Line mechanisms must have protective fences. To fill raw products in the mechanism of self-training it is possible only at full stop of the car. It is forbidden to fill the test tape in the calibration rolls of the machine when it is working. It is not allowed to clean the shredder of the pneumatic conveyor from the scraps of the test strip while the press is working.
Connections of the plating of the line chambers must provide the necessary sealing, preventing the release of steam, hot air and dust into the room. With the general switching-off of the current in the shop, the starting devices are switched off at all sections of the line. All starters must be enclosed by enclosures; Electric motors and covers are grounded. Fans must have mesh fences that restrict access to rotating impellers.
Workers serving the line must be dressed in suits that ensure safe operation on line machines.
Safety on the lines can also be provided on condition of uninterrupted operation and synchronous interaction of individual machines and line installations.