Bulk Materials Industry

Bulk Materials Industry – Conveyor belt tunnel

Conveyor belt tunnel made of Hamco corrugated steel parts have proven themselves below stock piles depending on the diameter up  to 40 m height. The storage of huge quantities of bulk material are always executed with stock piles if enough space exists, the  retrieval or the extraction take place irregularly and ergo a temporary storage of huge quantities is necessary.
Material stored on stock piles is transported economically and full-automatically to the further processes or loading station with help  of the conveyor belt tunnel located totally under the stock pile. At the top of the tunnel several openings (funnels) are placed with  defined distances. The funnels are equipped with remote controlled opening devices ensuring the transport of the desired  composition of the bulk material on the conveyor belt. The conveyor belt ends outside the tunnel at the top of a transport vehicle or inside an further process plant.

Advantages of Hamco conveyor belt tunnel:

 High level of economy by standard produced pieces.

The transport capacity of a conveyor belt tunnel is determined by the quantity and size of the funnels, performance of the opening  devices and conveyor belts. Inside a well dimensioned plant all of the performance ratings are coordinated to each other. The size of the funnels and the width of the conveyor belt constructions determine the dimension of the Hamco conveyor belt tunnel. Depending  on the operational requirements an one-sided or double-sided control walk is provided beside the conveyor belt serving  simultaneously as required escape route.
For one-sided and a conveyor belt width of 600 mm control walks conveyor belt tunnels with min. 2,84 m diameter are acceptable.  Higher width of the conyeyor belt and the demand of double-sided control walks requires additional space and the choice of a tunnel with a higher diameter. After the setting of the tunnel dimensions the statical required plate thickness can be determined. For several common used profiles the most important dimensions are shown in the table beside. Over time for the installation of the belt  construction and the production of the walking surface, the following simple and reliable construction method has proven itself: In the lower, not-used part of the pipe a gravel-sand mix is filled and compacted. On top of that a 20 cm layer of concrete with simple  grade together with a steel fabric mat is laid. The posts of the belt construction get foot plates, which are fixed to the concrete layer.
Anyway it must be avoided that vertical construction parts connect the top and bottom of the pipe. Lighter opening devices are  functionally connected directly to the funnels. Heavy opening devices are free-standing positioned on the concrete floor. In that case  enough space between funnel and opening must exist. Funnels with different dimensions will be delivered together with the Hamco  conveyor belt tunnel. Those funnels consist of welded single steel sheets and a stiffened angle steel frame serving simultaneously as connection for lighter opening devices. The funnels are completely welded inside of one of the top steel sheets of the pipe. The steel  sheet inclusive the funnel are hot-dip galvanized like the other sheets.

Bulk Materials Industry – Silos

For gravel and ore treatment plants silosmade of Hamco prefabricated steel parts have proven themselves. The positioning of the silos of a battery provides the storage of seperated grain sizes without having long transports but with the full availability of the stored materials. To make the loading independent from the production a conveyor belt tunnel is laid below the silos. The conveyor belt existing inside the tunnel is filled by funnels and opening devices.
The material coming from the digging field is transported after preseperation, elimination of not usable grain sizes, via conveyor belts to the treatment plant. Raw gravel comes sorted, washed and drainaged as well as separated by grain sizes into the different silos. Automatic plants are able to control all conveyor belts and opening devices corresponding to a fixed procedure from a central control stand. From here the opening devices located below the silos are set precisely regarding the grain size groups. The operating  conveyor belt inside the tunnel gets simultaneously the preset grain size group from each opening device. Caused by that the gravel delivey grants the required grain curve. On demand it is possible that each opening device fills the conveyor belt with a single grain size.
The Hamco Multi-Plate construction method enables the manufacture of silos of any size. With the silo height and the set capacity the required silo diameter can be determined. The exact calculation of the usable silo content depends on the quantity of the  opening devices and the grade of filling. To derive the friction forces at the wall steel beams are fixed at the outer diameter and
on the foundation.

Advantages of a Hamco silo:

* Hamco MP200strength® is a modification of the vertical bolting to carry even higher statical loads.