GERTECH Handling Systems offers the design, manufacturing & supply of Tube & Chain conveyors. Tube & Chain conveyors are also known as Chain disc conveyors, Tube disc conveyors, Rope & Disc Conveyors, Grain pump systems, Grain pump loop systems, or Grain loop systems.
This single conveyor system can consist out of vertical- and horizontal conveying sections, all part of the same conveyor.
It replaces the bucket elevator and horizontal conveyors traditionally used to take the product to its destination. A single Tube & Chain conveyor (T & C Conveyor) can, therefore take care of the filling, as well as the reclaiming functions to- and from the silos.
Conveyed product is moved in plugs and this method of conveying is gentler on any type of grain compared to the more traditional methods of bucket elevators and chain conveyors. The grain should fill around 80% of the available cavity between discs. Overfilling to maximum capacity puts too much strain on the conveyor components and is not recommended. Tests in existing grain handling systems have shown considerable reduced damage to grain kernels when a Tube & Chain system was used, compared to a traditional conveyor system.
Handling of traditionally difficult and abrasive products:
Gertech has successfully developed the Tube & Chain Conveyor to convey white granular sugar through horizontal and vertical conveyor sections. Conveyor and chain is mainly built out of stainless steel to conform to international food quality standards.
- Combining the functions of multiple conveyors into one conveyor;
- Capacities between 5 and 310 t/hr ( based on maize @ 721 kg/m3);
- Ideal for free-flowing and semi-free-flowing products;
- Reduced product damage due to plug flow;
- Long conveyor lengths;
- Heavy industrial designs available;
- Simpler truck off loading structures - therefore the overall project costs are considerably cheaper;
- In the case of conveyor tube wear occurrence, tubes can be rotated twice (by 120 degrees each time) when worn. After completely worn, the tubes are easy to replace, since standard South African popular size tubes in straight lengths are used.
In the case of a loop-system the four corners are made up out of a tensioner corner (on ground level) and a drive corner (normally positioned at top corner, after last outlet). The remaining corners are standard idler corners. In the case of long conveyors, two drives can be used to spread the load evenly. In this case both top corners are drive units. Length of the conveyor is determined and limited by the chain used.
A typical product intake can be in the form of a grain intake pit where the rate of intake is adjusted to not exceed 70% filling. Intakes can also be placed inside a silo floor where, again the rate of intake can not exceed 70%. Intake can also take the form of a receiving hopper from an existing conveyor – for instance, from a steel silo. Loading capacities should always be checked by visual inspection before the first corner after the intake and also be monitored by an amp meter on the electric drive. Overfilling the conveyors could cause plugging and undesired strain on the chain and drive units. To start up a conveyor, Gertech recommends using electronic soft starting devices only.
Tube & Chain Conveyors do not only have to be positioned in a looped configuration. A "doubled barrel" format can also be used to convey product at high capacity from one point to another.
Diameter of Tube (mm):
*Capacities are based on dry clean grain with a bulk density of 750 kg/m3.
Drive kilowatts are determined by the total length of filled conveyor. Proper grain storage management might require that the grain needs to be moved from one silo to another.
This results in the longest distance of filled conveyor and this will determine the final drive kilowatts of the system.
Contact Gertech to assist in determining the required motor kilowatt.
The following basic possibilities exist when this system is used to service storage systems for free flowing or semi-free flowing materials:
- Vertical loop :
For instance, to fill - and reclaim from silos using a single conveyor;
- Inclined, or slanted loop :
Used also to fill - and reclaim from a row of silos, but inlets from silos are outside the silos;
- Double barrel, or parallel tube :
For instance, to fill silos, or to convey grain over longer horizontal distances;
Configuration - Either straight line, horizontal conveying, OR inclined conveying to a maximum of 60 degrees;
- Combination of loop & double barrel.
Power Failures during conveying:
In case of a power failure the grain inside the vertical up-leg flows down and fills the lower pockets completely, making it difficult to start up under full load conditions. To overcome the additional strain on the chain during the start-up after such power failure it is recommended to purge the vertical leg by opening the bottom inspection window of the lower bend and drain the vertical leg of the conveyor. This procedure is especially recommended when power failures are a regular occurrence.
To off-load free flowing materials (or semi-free flowing) it is standard practice to dump the contents of a bulk truck into an intake pit. A pit for a Tube & Chain Conveyor takes the form of a simple steel hopper with an adjustable outlet into the conveyor which runs underneath the hopper to pick up the product. Gertech supplies this steel pit as part of the conveyor. An economic size of hopper takes around 8 tons of maize but this could be increased or decreased as required. Just take into consideration that a bigger pit requires more height above the conveyor and the truck support grid might have to be lifted to overcome this increased capacity. However, compared to the traditional intake pits used for bucket elevators, this should not be a problem. Intake pits for Tube & Chain Conveyors are much shallower compared to the pits for bucket elevators. The centerline of the conveyor is 1.45m below the top of the truck support grid.
Compare this to the pit required for a standard bucket elevator which is way deeper compared to the shallow pit used for the Tube & Chain Conveyor:
It is not difficult to realize the cost saving involved comparing the two type of pits. This results in a considerable indirect cost saving when the whole project is taken into account.