When we decide to install a weighing system in a Silo, a Hopper or a tank, we must take into account several fundamental questions:
Curb weight and full load weight. The capacity of the load cells must be dimensioned very well, since the silo or hopper are usually always loaded ; what the load cell is always working with.
EPOCH INSTRUMENTS & CONTROLS PVT LTD recommends working at a maximum of 50% of the maximum load of the Load Cell.
The height of the silo: The forces exerted on the load cell due to the action of the wind will vary if we are working on a silo of three meters or another of six, regardless of its load.
Usually what is known as an anti-tip system is mounted; basically a mechanical system that supports a load cell and prevents any movement on it other than the perpendicular force of the weight itself. Weight centering can be done by pin or ball.
These anti-tips are prepared for easy installation, usually with four holes on the top and four on the bottom.
Load cell for silos
and hoppers
On this page you can see different types of anti-tip. Anti-tip load cell systems
It remains to decide where to mount the anti-tip system. Often the simplest is to place it at the base of the hopper or silo feet; always starting from extremely well level ground. Another way of placement is on the brackets that support the tank or on the upper beams of the same.
Finally, it will be left to decide if the anti-tip to mount will be in stainless steel or in galvanized steel. Usually for the food industry it is necessary to mount the stainless ones; in the rest and even outdoors, they are used to mounting of galvanized steel basically because they are considerably cheaper.
Choice of electronics.
In principle, the same system can be used as that used for any scale or balance, there are no special specifications for the case of weighing in silos, hoppers or tanks.
The only thing to keep in mind is if you want to do some kind of dosage, which is quite common in these facilities.
There are several equipments that allow incorporating a relay card to be able to dose. What is done in these cases is to connect the relays to the dosing systems, such as solenoid valves or motors. The indicator has a special program that can be configured by the user, with limits, bulk weigh, fine and coarse weighing, etc. The indicator also incorporates auto-coupled inputs for start and stop.
The one commonly used is the VN1 with relay input / output. Here you can see the technical sheet:
Data sheet VN1 weight indicator
There are also equipment to work in a metal cabinet, both in a panel system (such as the panel-capable VN1) and on a din rail (such as the V-DIN weight indicator)
Here you have information on both:
VN1 Panelable Weight Indicator
Weight indicator for DIN V-DIN rail
Pivoting load cell upgrade
I wanted to comment on the improvements to the C-150 load cell over similar models offered by other manufacturers.
C150 load cell
Normally these types
of cells break down for two main reasons:
First, because in many cases they end up working submerged, since the weighbridge pits can end up flooded.
Second: due to the effect of atmospheric discharges. Scales attract lightning, and electrical discharges from these tend to burn the internal circuitry of load cells.
To eliminate moisture problems, the C150 load cell housing is welded with a complete micro laser welding wire, ensuring that no pore remains on its surface. As if this were not enough, the interior is protected with a special silicone, highly resistant to humidity. The cable gland through which the cable enters has a double internal protection, in case the internal O-rings deteriorate over time. We thus achieve an IP69K degree sealing, the best that can be found on the market.
Regarding the problem of storms, we have incorporated two gas dischargers to each load cell, to double the protection against them. We also add a special circuitry, more dimensioned, to protect the tracks against an overload.
Finally we have a precise and above all very reliable load cell.
EPOCH INSTRUMENTS
& CONTROLS PVT LTD is also one
of the Tension Load cell manufacturers in
Bangalore.
