In my last post I said that to measure the “Depth of Cement in the Silo” in a Cement Raw Materials Handling Facility, you need to know the silo’s volume. This is true for a silo with a flat bottom and an opening at the top.

But many cement storage facilities have conical bottoms, so in this case you will also need to know the change in diameter of the cone. The change in diameter can be measured by taking several measurements at different heights and subtracting them.

The reason you need to know the silo’s volume is because if you want to calculate how much cement is left in your silo, you need to know how much space it occupies. You can do this by measuring the height of cement in your silo and multiplying it by its cross sectional area. But you’ll also need to account for any gaps between the cement and the side of the silo, which are bound to be there unless your silo has a perfectly smooth wall surface (which would cost more than most companies can afford).

If your silo has a cone bottom, as mentioned above, then you will also need to take into account any change in diameter at different heights up from ground level when calculating its volume.

Warning: This is a method for measuring the height of cement in a silo. It is NOT to be used as a safety measure.

From an operational point of view, it is important to know how much cement is left in your silo at all times. To do this a “depth indicator” was developed by the author which gives a reliable indication of the amount of cement in any silo up to a maximum height of 105 feet. The depth indicator consists of two parts, namely:

1) A graduated rod with its zero mark at the bottom and graduated in feet and inches up to 100 feet; and

2) An aluminum ring with holes punched in one inch spacings around its circumference. This ring fits over the top of the silo and touches the surface of the cement within the silo.

The reading on the graduated rod is determined by lowering it into the silo until it touches the surface of cement inside, and then reading off how far down from the top it has sunk. The reading can then be compared with that on your gauge board (if you have one), or made directly on your silo plan which should be mounted on an adjacent wall for this purpose.

If you are new to the cement or ready mix concrete industry, you probably have a good idea what a cement silo is, but have little knowledge about how much cement is actually in the silo or how to determine how much silage you have in inventory.

While doing my research, I found that most articles explain the process of how to measure your silo height, but don’t actually tell you what your readings mean. After all, if you can’t determine the depth of cement in your silo, then measuring it becomes pretty pointless.

There are several ways to measure the amount of material in a bulk storage vessel. The simplest and least expensive method is based on weight. Suppose that you know the size of your kiln feed bin and want to know how full it is. All you need to do is weigh your bin and multiply by the bulk density of material in it. This requires that you know two things:

1) What your capacity is (the volume)

2) What the density of your material is

If you know these two things, you can determine with certainty how much material is in your silo at any given time.

The level of cement in the silo is measured with a rotating probe. The probe inserts into the cement from the top of the silo and rotate around its axis, at some point the probe will make contact with the cement. There are two types of probes:

1. Linear movement probes: These types of probes “scan” in a linear fashion (up/down) and read the analog resistance value to measure distance.

2. Rotational movement probes: These types of probes rotate around their axis, when they are making contact with any object they stop rotating. There will be an indicator on the top of these types of probes which shows the level at which they stopped rotating.

In both cases, there is a screw jack used to raise or lower these probes into or out off the silo. The screw jack is powered by an electric motor.

The rotational movement probe’s indicator should be calibrated from zero to one hundred percent using a manometer (water column gauge).

The cement silo is a simple storage for cement. The cement out of the silo through the screw conveyor sending to the weighing hopper. The hopper has a load cell which can measure the weight of materials. By measuring how much material is left, we can tell how much material is in the silo.

There are several methods to measure the amount of material in a silo. In this article we look at two issues that can be measured by sensors. The two measurements deal with weight and volume.

Weight measurement

The most common method for measuring weight is to use a load cell, mounted under the silo, or on top of the supporting structure for the silo. These devices are very accurate and relatively inexpensive.

The main problem with using a load cell is the connection of the sensor to the material being measured. If the material is a solid that does not compress, such as cement, then there is no problem: simply place a solid plate between the load cell and the material. If you want to measure liquids, however, then you have no choice but to immerse the load cell into it.

If you are measuring a solid that will compress, such as sand or gravel, then you must design a special connection between the load cell and the material being measured. This can be done by placing an extra coarse screen between them.

Cement Plant Manager at a cement plant in Chile.