Design of pipe conveyor pdf

The magnitude of this scuffing resistance depends on the amount of misalignment as well as the co-efficient of friction between the belt and idler roll. The co-efficient of friction will in turn depend on whether the belt surface is dry, wet or moist. The conveyor resistances for each section of the conveyor are calculated using the methods shown in the Viscoelastic calculation method as described above.

The four main resistance components Indentation, Flexure, Idler Rotation and Skew and Tilt resistance are then added to give a total resistance R for each section of conveyor. You can see from the above report that in the carry sections of the Pipe Conveyor, the total friction factor varies in sections with no horizontal curves and increases in the curved sections. In the report shown above you can see the proportions of the resistances as a percentage of the total for each section: Carry side Section 11 Indentation loss is about Indentation losses are lower on the return run than the carry side due to no material mass.

The proportions of each resistance component can vary widely depending on the belt rubber properties, belt speed, idler spacing and idler rim drag. The designer should explore different settings to get an optimal design. Pipe Conveyors have some additional features compared to conventional troughed conveyors, i. These sections of the belt are called transitions; they are similar to the Trough Transition in a conventional Troughed belt conveyor, except that the edge length hypotenuse is longer as the belt goes from flat at the pulley to more than degrees of closure.

Refer to the Horizontal Curve Calculations help topic for an explanation. The required minimum length of the transition is governed by limiting the edge tension rise and also limiting the center tension drop which results for the edges being stretched.

In a Pipe Conveyor curve, the portion of the belt furthest away from the centre of the curve is stretched while the portion or half of the belt on the inside of the curve is compressed into a shorter length.

We need to ensure that the rise in tension does not exceed the working tension of the belt and also ensure that the reduction in tension on the inside does not force the belt into compression because it will buckle. One the main advantages of Pipe Conveyors is that they can negotiate relatively small radius Horizontal curves when compared to conventional Troughed conveyors.

Each vertical and horizontal curve in a Pipe Conveyor needs to be checked for: Belt Tube Outside belt tension rise - too high a tension will over-stress the belt Belt Tube Inside belt tension fall - too low a tension will make the belt go into compression and cause tube and belt buckling Concave Vertical curves must have sufficient radius to ensure that the belt does not tend to lift off the lower idlers and cause the tube to be compressed against the upper idler rollers.

The belt lift is caused by the belt tension resultant force from the change in vertical angle. This calculation is the same as for a Troughed conveyor.

Concave and Convex vertical curves have a Belt Tube Outside upper half belt tension rise - too high a tension will over-stress the belt Concave and Convex vertical curves have a Belt Tube Inside lower half belt tension fall - too low a tension will make the belt go into compression and cause tube and belt buckling.

The required minimum concave curve radius for belt lift off for Item no. For each Concave and Convex vertical curve and each Horizontal Curve in a Pipe a Conveyor, the Calculate Pipe Conveyor Curve calculation under the main form Calcs menu must be used to check for high and low tensions in the curve. Refer to the Calcs menu shown below. Enter the input values for the curve under consideration.

You can enter a Curve Description which shows the location of each curve so that this description can be used to identify which curve has been calculated. The belt is stretched through a further distance in the outside of the curve and travels through a shorter distance in the inside of the curve. Pipe Conveyors. Special Belt is required. This results in a higher demand power. Return belt resistance is normally substantially higher than conventional troughed conveyors due to larger number of return belt rollers rim drag is increased.

The Helix delta-T6 Program has three main methods of estimating the conveyor resistances, namely: ISO DIN Method CEMA method VISCO method - this method uses the rubber rheology properties to calculate the indentation resistance of the rubber belt on the conveyor idler rollers and also calculates the material and belt flexure losses , the idler rotation rim drag losses and the belt to idler scuffing losses.

These four components make up the total resistance to movement of the conveyor belt. Build the model of the conveyor in the normal way as described in the Getting Started help topic in the Helix delta-T6 Program. These specific idler dimensions are theorectical only, designers must obtain real idler data from their own manufacturer for final design. Repeat the pipe conveyor Idler Selection process described above for the Return Idlers The Number of Idler Rolls must be six 6 for a Pipe Conveyor Now return to the to Belt Input Details form and the Belt Cross-section will be redrawn with the selected Idlers and Belt Width The cross-section above shows the percentage full and belt overlap length as well as the chosen idlers.

The Maximum Belt speed will depend on the Idler Load and Bearing life and should be adjusted to give an idler rotation speed of less than rpm. There are no known published maximum belt speed limits for Pipe Conveyors, but as for Troughed conveyors, a speed higher than about 5.

If the conveyor routing has a lot of horizontal and vertical curves with small curve radius, the belt stiffness should be increased as accordingly to manage the bending effect for curves, so that the belt does not have additional rotations, twist and collapse. It must include both the belt manufacturer and system engineer's responsibility to work together and to Figure 1. The upgrade of Confine pipe belt includes both There are many different ways in designing the belt experimental and numerical calculations.

External tests stiffness. They generally fall into two major categories: were carried out to verify the Confine belt construction. Figure 1 shows a mm nominal diameter, mm wide ST Confine steel cord pipe belt mounted on a six Early analysis of pipe conveyors are based on analytical point pipe belt stiffness testing device.

It has six contact simplification of the pipe belt behaviour. Now in recent , points on the folded pipe belt sample, where the contact the finite element analysis FEA is gaining more popular force is measured as an indicating unit of the belt to simulate the pipe folding and curving behaviour. However, the FEA of pipe conveyor belts is a highly nonlinear simulation and more expensive. Finite element analysis FEA is also used extensively to equip the design of the confine pipe belt.

Other FEA of pipe belts, simplified shell or sold elements are used to represent both rubber, steel cord and fabric materials, a complete model where the rubber, steel cords and fabric layers are modeled individually with their own material properties.

The overall bending form of pipe belt in FEA is calculated with both the three point bending and six point stiffness testing. With FEA, various operating factors can be exanined.

Pipe belt carrying material can be modeled, to examine the various effects of belt sag and belt deformation from material loading. Figure 2.

Figure 2 shows a three point bending stiffness testing device. The three point bending is a well defined and caliberated bending test. As Compared to the six point stiffness test, it is much easier to make test samples and generate design libraries based on the three point bending test. It requires a good numerical and experimental correlations between the three point bending stiffness and the six point pipe belt stiffness. Once they are established there is no need to verify full width belt samples and go through a trial-and-error process for each designed belt before the actual belt production.

Figure 4. The fidelity of the modelingis given in Figure 5, where an actual Confine pipe belt shape is compared closely to the FEA model. Modeling of the pipe belt during both horizontal and vertical curves provides the tool to analyze the proper pipe belt stiffness required for horizontal and vertical curves.

Figure 3. FEA simulation of Confine left and Figure 6. Resistance Pipe Belt. Figure 5 shows a conventional steel cord pipe belt deforms Figure 6 shows a mm diameter pipe belt with Low at horizontal curves due to the bending effect of the Rolling Resistance pulley cover compound which is tensioned belt right image. The pipe belt lose contact installed in a power plant at Bulgaria.

The conveyor is long with the idler rollers and its diameter decreases. If the belt as about 2. The main neccesity of LRR pipe belt is to stiffness increases, such deformation will decrease. The reduce the power consumption and belt tension. This is pipe belt fabrication also affect the belt behavior during also the world's first LRR pipe conveyor belt.

Modelingof pipe conveyor cost and operating cost, as well demonstrated in overlong belt behavior during the curves is quite complex, in trough conveyors. Such demanding simulations become feasible wide temperature range to the conveyor belt.

As the pipe only in recent years due to the fastly growth in computing belt transports the hot material, elevated temperature power with decreasing cost. Ever since the newly launch of the Goodyear Pipe Belt Project in , over 40km long of Confine steel cord and fabric pipe belts have been installed and running successfully with a possituve results.

Besides regular belts, special types of pipe belts are also manufactured to meet the customer need. From the viscoelastic properties and contact pressure, the indentation losses over each idler can be calculated. This method approach the problem of calculating pipe conveyors from fundamental physics, rather on the basis of empirical relations. It consists design optimization based on LRR and design for specialty belts such as heat resistant pipe belts, as the range of design problems that can be illustrated is much wider.

Conveyor Dynamics, Inc. Dynamic analysis is a powerful tool to examine the conveyor starting and stopping behavior. Figure 8. The first 3. The dynamic analysis involves the system designer to have a Conveyor Dynamics, Inc. Firstly, the pipe belt stiffness is sudden loss of motor power and reduce excessive high determined bm on the basis of maximum belt tension and belt tension during starting, design safe and reliable smallest curve radius, so as to prevent excessive belt stopping mechanism for a downhill conveyor, synchronize rotation and twist , and prevent high power requirement the stopping of upstream and downstream conveyors, etc.

The optimized belt stiffness, The general material handling system is also the contact pressure on the idler rollwr can be obtained by beginning to realize the importance of dynamic analysis. FEA and experimental data. This contact pressure changes Many system user now demand dynamic analysis to be with belt tension, material loading and conveyor shape. Both Experimental testing and numerical simulation on pipe conveyor belt are being reviewedin this paper.

Field installations with specialty belt such as low rolling resistance belt and heat resistant belt are also demonstrated as successful implementation of the Confine pipe belt. Low rolling resistance belt, with betterconsideration of the mechanics of the pipe belt and pipe conveyor system, and system control from dynamic analysis will give a better performance.

Nordell, L.