Tolva de inyeccion de extrusion de polimeros

A hopper is a large, pyramidal or cone shaped container used in industrial processes to hold

particulate matter Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The ter ...

or flow-able material of any sort (like dust, gravel, nuts or seeds) and dispense these from the bottom when needed. In some specialized applications even small metal or plastic assembly components can be loaded and dispensed by small hopper systems. In the case of dust collection hoppers the dust can be collected from expelled air. Hoppers for dust collection are often installed in groups to allow for a greater collection quantity. Hoppers are used in many industries to hold material until it is needed, such as flour, sugar or nuts for food manufacturing, food pellets for livestock, crushed ores for refining, etc. Dust hoppers are employed in industrial processes that use air pollution control devices such as

dust collector A dust collector is a system used to enhance the quality of air released from industrial and commercial processes by collecting dust and other impurities from air or gas. Designed to handle high-volume dust loads, a dust collector system consists ...

electrostatic precipitator An electrostatic precipitator (ESP) is a filterless device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit. In con ...

s, and baghouses/fabric filters. Most hoppers are made of

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

Process

Materials can be added either manually or automatically to the top of a hopper. For dust collection, it enters the hopper from a collection device. For example, baghouses are shaken or blown with

compressed air Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and o ...

to release caked-on dust from the bag. Precipitators use a rapping system to release the dirt. The crumbling dust falls into the hopper. Once the material in the hopper reaches capacity, it is released through an opening in the bottom with a diameter of about . Hoppers are rectangular or circular in cross section but have sides that slope at about a 60° angle. Slanted sides make it easier for the contained material to flow out. Conveyors are sometimes used to carry away the particulate matter.

Important components

Hopper walls are often insulated to protect the outside environment and personnel from the contents. Often, the bottom 1/4 – 1/3 of the container is heated to eliminate the possibility of condensation inside the hopper. The greatest difficulty associated with the removal of very fine material, like flour or dust, from a hopper is the compaction of the material. Moisture content, particle shape and size, and vibration are all factors that contribute to compaction. Typically, with such fine materials, vibrators are installed on the outer walls of a hopper to shake and release the material, however other kind of discharging aids can be considered if necessary.{{Cite web, url=https://powderprocess.net/Powder_Flow/Solve_Flow_Problems.html, title = How to solve powder flow problems in silos (Bad flow, no flow) - Arching / Ratholes

References

Air pollution control systems