APRON BELT FEEDERS
Benefits and Features
APRON BELT FEEDERS
Apron Belt Feeders (ABF), sometimes known as Low Profile Feeders (LPF) or hybrid belt feeders, are a proven solution in heavy duty mining and industrial applications where features and benefits from both belt feeder and apron feeder technologies are merged.
Our mechanical engineers have over ten years of experience in the design of hybrid feeders in many heavy duty applications. The BHT Apron Belt Feeder is an improved design based on this experience and is designed and manufactured to ensure long life and reliable service in the harshest of operating environments.
Using only proven, quality components, our designs meet or exceed Australian Standards and can include the design and supply of a complete system including feed hopper, structure, isolation gate and discharge conveyors as required.
By working with BHT for the supply of your next Apron Belt Feeder you will enjoy the following benefits;
A tailored solution, engineered to suit customer specific site requirements,
Compliance to customer engineering and manufacturing specifications,
A consultative design process utilising the latest industry standards and guidelines for material flow properties, Australian Standards and BHT proprietary design systems,
The confidence of Finite Element Analysis for major structural and mechanical components,
Provision of 3D models to allow convenient integration into overall plant layouts to ensure accurate interface and tie-in with connecting chutes and infrastructure.
Utilise quality components and a consideration in employing as many common components to reduce spares for the customer.
Belt & Chain
As mentioned earlier, Apron Belt Feeders have the advantage over belt feeders where the tension cause by shear force and friction losses are transferred to the chain rather than the belt. Consequently the selection of the belt is not critical to the performance of the machine, only the life expectancy.
Rather than friction driving between the belt and the head pulley as per belt feeders, the Apron Belt Feeders use the sprockets which positively drive the chain. Consequently as the working tensions increase, the diameter does not change until a stronger chain model is required.
In order to transfer the loads from the hopper into the chains, pans are required as a connection between the belt and the dozer undercarriage chain. These pans are fastened to the dozer chain using high tensile bolts and standard dozer square track nuts, while the belt is fastened in place using specially manufactured drop forged bolts. A feature of the Apron Belt Feeder is that the pan cross section can be increased size, and therefore strength, for very wide machines requiring that added strength.
Normally there are only one or two belt joints on an apron belt feeder dependent on transport requirements. These joints are designed and manufactured as mechanical joints where skived belt ends are overlapped and then clamped with a plate. This setup allows easier installation and disassembly of the belt at site and does not require a large vertical area for cold or hot splicing.
The task of the rollers on an Apron Belt Feeder is to transfer the vertical load from the chain and belt assembly into the structural frame.
There are two types of rollers employed by the apron belt feeders; carrier rollers and track rollers. The two differences between the rollers are; firstly the carrier roller utilises a cantilever shaft while the track roller uses a through shaft which is support at both ends, and the second is that the carrier utilises roller bearings while the track as plain bearings. This dictates that the carrier rollers have a lower load rating than the track rollers and hence carrier rollers are not typically suited for high loaded areas but for supporting the conveying section or return chain belt assembly.
Unlike a belt feeder where the take-up is required to provide additional tension so that the belt can transfer the force into the head pulley using friction, the apron belt feeder only requires the take-up to reduce the sag between return rollers. Therefore the relative take-up forces required are much lower when compared to belt feeders.
There are two options for the take-up assembly; utilisation of a simple mechanical threaded rod take-up, or an assisting hydraulic cylinder with mechanical lock. The usage of the hydraulic cylinder option is really only required on long machines where the required force to reduce the catenary is large and becomes too difficult to adjust by hand.