The Archimedes screw pump is a kind of screw pump invented by the ancient Greek mathematician and scientist Archimedes when he was in Egypt. This is the earliest water pump in history, and its principle is still used in modern progressive cavity pumps.
The working principle of the Archimedes screw pump is that when the motor drives the pump shaft to rotate, the screw rotates around its own axis on the one hand, and on the other hand it rolls along the inner surface of the bushing, thus forming the sealed chamber of the pump. With each revolution of the screw, the liquid in the sealing cavity advances a pitch, and with the continuous rotation of the screw, the liquid is pressed from one sealing cavity to the other in a spiral manner, and finally squeezes out of the pump body. The screw pump is a new type of liquid conveying machinery, which has the advantages of simple structure, safe and reliable operation, convenient use and maintenance, continuous and uniform liquid discharge, and stable pressure.
The working principle of the Archimedes screw pump cannot explain that “water flows upwards”. Take any section of liquid for observation. Both ends of the liquid are horizontal in the direction of gravity. The pump shaft rotates so that the lower end of the liquid in the direction of the screw is higher than the upper end. Under the action of gravity, the liquid flows from the lower end of the high level to the upper end of the low level. Air does not provide power, and the air pressure inside each section is equal to the outside.
In modern factory applications it is called a screw conveyor.
The screw conveyor has the advantages of simple structure, low manufacturing cost, strong sealing, safe and convenient operation, etc. It can be loaded and unloaded at multiple points in the middle. It is widely used in chemical industry, building materials, metallurgy, grain and other departments. Under the condition of inclination angle β < 20 °, it can transport powdery, granular and small pieces of materials that are not viscous, not easy to deteriorate, and do not agglomerate.
Screw conveyors are widely used in various industries, such as building materials, chemical industry, electric power, metallurgy, coal mining, grain and other industries, suitable for horizontal or inclined conveying powder, granular and small block materials, such as coal mine, ash, slag, cement, grain etc., the material temperature is less than 200℃. The screw machine is not suitable for conveying materials that are perishable, viscous, and easy to agglomerate. In the concrete mixing plant, the role of the screw conveyor has been reflected to the greatest extent.
It is composed of a driving device to close the tank and a screw, and the coal in the tank is pushed and output by the rotation of the screw.
The characteristics of the screw conveyor are: simple structure, small cross-sectional size, good sealing, reliable operation, low manufacturing cost, convenient intermediate loading and unloading, the conveying direction can be reversed, and can also be conveyed in opposite directions at the same time. During the conveying process, the materials can also be stirred, mixed, heated and cooled. The material flow can be adjusted through the loading and unloading gate. However, it is not suitable to convey materials that are perishable, viscous, easy to agglomerate and bulky. During the conveying process, the material is easily broken, and the screw and the trough are easily worn. The unit power is larger. In use, the sealing of the trough and the proper clearance between the screw and the trough should be maintained.
Vertical screw conveyor is suitable for short-distance vertical conveying. The screw of the flexible screw conveyor is composed of a flexible shaft and a synthetic rubber blade, which is easy to bend and can be arbitrarily arranged according to the site or process requirements for space conveying. The screw conveyor blades have existing pull type and full pull type. The existing pull type can be made into any thickness and size. The whole pull type is not suitable for making non-standard spirals.