Standards for conveyer design
by Ing. Gustavo Sosa, CEO of Sosa Ingenieria, USA
In our Latin American market, we suffer a lot because of the lack of standards. Even the piping isn't uniform. It depends on whether the supplier is Argentinian, Brazilian or Chinese. This means the sizes of all the fittings are different, even some of the conveyors.
As professionals, one of our main responsibilities is the creation and promotion of technical standards that will lead us to economies in the maintenance during the whole lifecycle of all the facilities and even on new projects.
Let's say we are expanding our facility, installing a new belt conveyor, and suddenly we realise it is five metres too short to operate properly. We call our supplier and he says he is overbooked and the delivery time is 60 days.
What do we do?Stop the works for two months? Even if you send the workers to Unemployment Insurance, you have to dismantle the camp and set it up again in two months. Besides, there is a lost income for the two months that the facility won't be yet operating at the new capacity.
Call our local steel workshop and tell them to copy all the structural pieces while we get the rollers somewhere else? It is very likely the workshop will take more time than they promise and the rollers have to be imported from China, Europe, or the US, and that will take at least 45 days for the sea freight.
Everything sounds absurd and there seems to be no solution. But there could be one, if manufacturers adopted common standards. In that case, the piece that one manufacturer doesn't have could be supplied by another one.
As manufacturers, at first view it might seem one is losing business, because you are lifting exit barriers for your clients. But you are also actually lifting the entrance barriers for new clients. It will even allow us to outsource production if we have too many orders and don't have enough capacity.
You don't even need to create these standards from zero. You may adopt others, created by international organisations.
CEMA is the acronym for Conveyor Equipment Manufacturers Association. Created in 1933, this association of manufacturers had the goal of sharing information and best practices in their industry. They also have strong ties to the Material Handling Industry Association (MHI).
The MHI is formed by companies and professionals in the material handling business (distribution centres, airports, factories in general, mail companies, etc), but their focus is far away from bulk solids and nears towards package handling.
The nature of CEMA standards is very practical, meant for straight application. They provide dimensions, formulas and calculation charts. Even things that any mechanical engineer knows, like sizing a shaft, are given in graphs so that any mid-level technician may use them.
Many manufacturers have copied the CEMA standards, but don't realise that a pdf downloaded through torrent or a technical catalogue from Martin Sprocket or KWS won't provide any assurance to the client. How does he know the standards are being followed and if those parts will be compatible with others? Only the membership can provide that assurance.
We also have the standards by the International Standardisation Organisation (ISO). In theory it is an NGO, but it has consulting status by the UN, and its members (the national organisations in 163 countries) have an important weight in the regulations of their local governments. It has existed since 1947 and its standards cover almost every human activity. The standards are of voluntary compliance, but respecting them gives a good backup to our technical decisions.
In some issues the standards of both organisations overlap each other, but generally the ISO is more theoretical. They give testing procedures and calculation equations of a high level, finding a better application in ambitious infrastructure projects (like very long belt conveyors) than in a humble mill. However, a high-level technician should know them, or at least know that they exist.
Maybe the reader knows the ISO 9000 quality standards. Well, these standards basically say you have to write everything you do and always do as it is written, but nowhere does it say what is right and what is wrong. For that purpose, it is better to apply the principles of Lean Six Sigma, which gives specific tools for process improvement. The best choice is to combine both approaches.
Although American manufacturers swear by the CEMA standards and the European manufacturers swear by the ISO, I think they complement each other. A small factory, with very little engineering capacity, would benefit a lot from joining CEMA to access that knowledge network.
A larger factory, looking to achieve a competitive advantage over others or winning large projects, could use the ISO standards to improve the design process. However, considering the current state of technology, those efforts would probably be better used improving manufacturing and maintenance processes instead of design.
Also, if some day the company needs to manufacture a 30-km belt conveyor to take soybeans from a dry terminal down to the port, without using trucks, it is better to start with the CEMA standards for an initial approximation and switch immediately to the ISO to smooth the design.
Technical standards (whatever the flavour) are not a substitute for careful engineering work, neither do they make up for the lack of training of an engineer, but they do speed up the design process and allow the creation of a budget and a quotation faster, if you never designed a similar equipment before.
Brazilian readers will be happy to know that, since many years ago, the ABNT (the local ISO organisation) has national belt conveyor standards taken from CEMA. They still don't have anything for drag conveyor, screw conveyors, nor bucket elevators.
It would be nice to see CEMA expanding their focus to alsocover pneumatic conveyors, but that is something to be decided by its members in the future.