Compass plate conveyor
- Added: 19.12.2014
- Size: 366 KB
- Downloads: 5
Job for Course Project
Define Common Parameters
Calculation of asterisk parameters
Selection of couplings
Engine start check
Chain Strength Check
Calculation of spring-screw tensioner
Calculation of drive sprocket shaft
Calculation of tension sprocket shaft
Selection of bearings
Bibliographic list of used literature
Plate-like conveyors are conveyors that move weights on a flooring formed of separate plates, typically fixedly attached to or integral with a flexible traction member.
To transport piece or fibrous cargoes over short distances and at low speed, conveyors with flat open (type PR as per GOST 2228176) are used with flooring without sides, as well as with flooring in the form of placed narrow strips or bars. Such conveyors can be used to move bulk pieces of cargo, such as root crops, if the clearance between the plates is less than the minimum size of the load piece.
With an increase in the speed and range of transportation, there is a danger of the cargo falling to the side. To avoid this, conveyors are equipped with fixed sides with guides - sides .
The installation of fixed sides and the use of flat closed or side-free wavy flooring make it possible to reduce the spilling of cargo under the web and to the side, so that such conveyors can be used not only for piece, but also for a wide range of bulk lumps. However, even with this design, small particles of cargo wake up in the slots between the fixed sides, wedge into them. There is also an additional resistance to movement from the friction of the load against the fixed sides.
These disadvantages do not have conveyors with onboard (tray) flooring, used to transport both piece and bulk cargoes of any size. Side wavy flooring is formed from plates overlapping each other on the bottom and on the sides. Such flooring has increased strength and rigidity, eliminates waking of the load to the sides. The load-to-flooring adhesion and the allowable conveyor angle are also increased. Despite the fact that when using onboard wavy flooring, the mass of the latter increases slightly, its use is quite justified in transporting large masses of bulk cargo.
Even greater adhesion of the bulk load to the flooring and further increase of the permissible inclination angle of the conveyor are provided by side wavy floorings with partitions 6, as well as box-shaped small and deep floorings. The box shape and baffles, which act as stiffening ribs, increase the strength of the flooring, so the conveyors with them are more adapted to move large, heavy and sharp bulk loads.
According to the principle of transportation (transfer on the web), plate conveyors for long piece weights moved on saddle-shaped plates with spikes attached to the chain at a great distance from each other are included. Such conveyors, widely
used in the forest industry, called logs. According to this principle, plate conveyors can be attributed to plate and
rod conveyor devices of widespread agricultural machines, in which they are used to transport fibrous cargoes (plank in grain and silo harvesters).
Plate conveyors are stationary and mobile with their own drive, as well as built into process machines with a drive from these machines. As traction elements of conveyors, chains of various types are most often used, mainly plate-like (GOST 58881). There are known plate conveyors with a flat loop flooring serving as a load-carrying and traction element, as well as conveyors with a traction element in the form of a belt to which carrier plates are attached.
According to the configuration of the route, plate conveyors are horizontal, inclined and combined (with several horizontal and inclined sections); according to the location of the traction element in space, usually vertically closed, less often horizontally closed (for example, conveyors for transporting luggage at airports) and bending in vertical and horizontal planes. Vertically closed conveyors are usually double-chain, and horizontally closed and spatial conveyors are single-chain. With a large width of the web, plate conveyors are made three- and four-chain (strip conveyors of agricultural machines). Plate conveyors are mainly made single-drive, less often multi-drive with end or end and intermediate arrangement of drives.
Basic parameters. Due to the use of chains as traction elements, the speed of the flooring of plate conveyors usually does not exceed 0.35 m/s, rarely reaches 1 m/s. However, due to the grooved shape and the large width of the flooring, their productivity can be 2000 t/h or more. The range of the non-transporting transport distance is much limited by drive conveyors. Installations up to 2 km long are known. The angle of inclination of the plate web can be 35... 60 °, and in some cases (box flooring with transverse partitions) - 70 °, although at angles of inclination above 35 °, the conveyor productivity is noticeably reduced, since the bulk load is reliably held only within the height of the partition. When transporting unit loads, the maximum angle of inclination is determined from the condition that the line of gravity G of the load is located inside the contour bounded by adjacent edges of the flooring.
In plate conveyors, significantly smaller rounding radii in concave sections (3... 5 m).
Advantages and disadvantages.
The advantages of plate conveyors over belts are their great adaptability for transporting large-piece, sharp-edged, hot and other similar loads causing damage to the belts; operability at both normal and high or low temperatures; Possibility of transportation of a wider range of bulk, bulk and piece cargoes; a wide variety of transportation routes (including horizontally closed and spatial with steeper rises and smaller radii of transitions from one direction to another, which ensures compactness of conveyors and minimization of losses of production areas in the lifting sections); the possibility of installing intermediate drives (which is practically not solved for other types of conveyors that provide non-transporting transportation over long distances; large cross-sectional area of the load on the web (with a tray shape of the flooring) and high productivity at a relatively low speed; possibility of flooring with special devices for cargo fixation taking into account the use of conveyors in process flow lines; possibility of loading directly from the hopper (without special feeders), provided by the structure of the web and its low speed of movement.
Disadvantages of plate conveyors include large mass, complexity of manufacture and high cost of running gear (plate flooring with chains); lower speed of the web compared to speed of belt conveyors; complexity of intermediate unloading of conveyors with side flooring; complicated operation due to the large number of hinges requiring constant monitoring and maintenance (cleaning, lubrication) and susceptible to increased wear and tear; The difficulty of replacing worn rinks; significantly greater resistance to movement (compared to belt conveyors, due to the greater intrinsic mass of the carrier web).
Application areas. Plate conveyors are used to move various piece bulk and bulk loads, mainly heavy, large-piece, abrasive, sharp-edged and hot. The most widely used are stationary and vertically closed conveyors with rectilinear routes, which are called general-purpose conveyors. In the metallurgical industry, they are used to supply coarse ore and hot agglomerate, at chemical plants and construction materials enterprises - to move coarse non-metallic materials (for example, limestone), at thermal power plants - to supply coarse coal. They have found wide application in mechanical engineering for the transportation of hot forgings, castings, sharp-crumb waste of stamping production, as well as on in-line assembly lines,
cooling, drying, sorting and heat treatment. Movable plate conveyors are used in warehouses, loading and unloading, sorting and packing points for transportation of tarn-piece cargoes.
Special plate conveyors, including bending with spatial routes, are used in the mining and coal industries to transport large, heavy and sharp loads (ore, coal) over long distances. In the food industry, plate conveyors with flat loop flooring are widely used to move bottles, cans, etc.
Strip and bar conveyor devices are used in various agricultural machines. Log trucks are equipped with warehouses of forest materials in the forest and woodworking industries .