Vibrating feeders and vibrating dosing feeders
Extraction systems
Vibroprocess vibrating feeders and vibrating dosing feeders are used for extracting bulky products from silos or bins or for feeding crushers, conveyor belts etc.. They stand out for high reliability and performance.
The above mentioned systems can easily replace other extraction systems such as box extractors, scraping belts, screw feeders, etc. boasting high benefits as they can be easily installed and require minimum maintenance.
Vibroprocess vibrating feeders can be up to 3,000 mm wide and 8,000 mm long. We have already designed and manufactured more than 1,500 installations worldwide.
Vibrating feeders classification
The vibrating feeders can be classified in three major categories, based on the principle of operation:
ELECTROMECHANICAL VIBRATING FEEDERS
They are driven by counter-rotating electric vibrators, mounted on the cross beam of the electromechanical vibrating feeder.
The unbalance motors generate a linear vibration, inducing the motion and the transport of the handled material.
The electromechanical vibrating feeders should be used only when flow rate variations with the machine running are not required, nor an immediate stop of the flow of extracted product. This work condition can be achieved by controlling the electric vibrators via inverter (frequency converter).
ELECTROMAGNETIC VIBRATING FEEDERS
They are driven by electromagnetic vibrators, mounted on the cross beam of the vibrating structure.
The electromagnetic drive generate a linear vibration, inducing the motion and the transport direction to the handled material.
The electromagnetic vibrating feeders should be used when you need to change the flow while the machine is running and/or immediately stop the product flow as soon as the machine is stopped.
The electromagnetic vibrating feeders are often called vibrating dosing feeders thanks to their versatility in changing the flow based on the requirements of both the plant and the process.
MECHANICAL VIBRATING FEEDERS
They are driven by an electric motor with direct transmission through a cardan shaft that moves the directional exciter mounted on the cross beam of the vibrating structure.
The directional exciters generate a linear vibration, inducing the motion and the transport direction of the handled material.
The mechanical vibrating feeders should be used for machines with large weight and size. This solution also depends on other factors such as the number of hours of operation per day, the temperature of the material to be processed, and the size of the material to be processed.
The electric motors of the mechanical vibrating feeders can be connected to a frequency converter in order to achieve the benefits already mentioned above.
Vibrating feeders design study
All Vibroprocess vibrating feeders were designed according to the product to be processed. The size of these machines is calculated taking into consideration several essential process data such as the amount of material to be extracted, while other design details are related to factors such as temperature, weight and particle size of the material.
ANTI-WEAR LINERS
Steel or anti-wear steel liners
The most common type of liners consists of standard steel sheets or easily interchangeable anti-wear steel sheets, bolted to channel structure. Their lifespan depends on their thickness and on the level of abrasion generated by the material to be processed.
Rubber sheet lining
The rubber sheet lining is suitable for some types of materials and is usually used for protecting delicate products from damage. This type of coating consists of sheets covered with a layer of rubber fastened to the structure, for easy replacement of worn parts.
Sheet with welded lining
If the anti-wear material should last for a long period of time, we recommend you use the welded lining. The price of this material is a little bit higher but it ensures best performance with respect to the thickness and the type of product to be processed. In this case the sheets are also fastened to machine body and can be easily replaced.
SUSPENSION AND ISOLATION METHODS
The method of vibrating feeders suspension refers to the various methods by which you can anchor the vibrating screens to the static structures of the machine.
Suspended execution
The suspended vibrating feeders are bonded to the static support structures using steel tie-rods and are isolated using steel coil springs or rubber springs if the screen is driven by electromagnetic vibrators. This method is economic and can be easily applied. But the machine may generate irregular movements during vibrators synchronization phase.
Self-suspended execution
The method with self-suspension allows you to flange the static terminal to the machine structures. The terminal welded to support structure, sustains the vibrating machine body isolated by means of springs. The self-suspended vibrating screen is fitted with rubber seals, inspection doors and dust suction nozzles. In some cases, it is equipped with a gate valve that shuts off the flow. Synchronization is performed instantly.
Supported execution
The supported feeders l refers to the vibrating screen supported by a static support structure ( support / frame ), isolated with springs. Synchronization of vibrators takes place almost instantly, upon start-up, without generating any irregular oscillations.
ISOLATING METHODS
Vibrating Feeders vibrations are isolated by two different types of springs. The spring type should be chosen based on the type of drive:
- Electromechanical vibrating feeders: coil steel springs
- Mechanical vibrating feeders: rubber dampers
- Electromagnetic vibrating screens: rubber dampers
Thermal isolation is provided by the double frame design. When the temperature of the product to be processed is high, a bolted frame is inserted between the machine trough and the drives cross beam.
Using the double frame, you can isolate both the cross beam and the drives. In fact, the temperature may cause thermal expansions that are not allowed on these machine parts and welds. It also facilitates the removal and replacement of the conveying trough, allowing the operator to perform this operation fast and easy. We can also make air gap passage under the bottom of the trough , in which hot air is conveyed to reduce heat exchange and facilitate the transport of sticking materials.
MATERIAL DISCHARGE
Material unloading can be adapted to the most diverse customer plant requests and ad-hoc studied from case to case. We can classify the two most common methods used.
Front discharge
In case of front discharge, the vibrating feeder is opened, without discharge nozzles or logs. The material is conveyed and unloaded from the front side in muffs or static terminals or directly on other equipment such as conveyor belts, vibrating screens, screw feeders etc..
Orthogonal discharge
Vibrating feeders with orthogonal discharge are usually fitted with dust-proof seals. The discharge nozzle is placed perpendicularly to the conveying trough. They are used for extracting powder materials to reduce to zero the dispersion of materials such as lime oxide, calcium carbonate etc..
The process of extracting bulky products using a vibrating feeder is similar to the conveying process. To define the extraction or the feeding process, machine centre distance should not exceed 2 ÷ 2.5 times its width; for greater distances, the process is defined as conveying process.