Designing for Efficiency

8/13/2019 Designing for Efficiency

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DESIGNING FOR EFFICIENCY

What is good prod uct design and how can manufacturers ensure that their productscontinue to meet and exceed the expectations of their custom ers?

Ask 100 people what good product design involves and you are guaranteed to get a variety ofdifferent answers. The truth is that there is no one factor that makes good design, but rather it isa combination of factors. All too often the emphasis for product designers is on the purelyfunctional aspects of product design does it work?

While this is of course essential, and probably makes up around 90% of the product designprocess, it is the last 10% that often gets forgotten. It is the focus on this last 10% that will makethe difference between a good concept, and a fantastic product.

So what does this essential 10% involve? How can product designers ensure that there isalways a focus on this essential part of product design?

The answer to this question involves looking not only how the product will function, but how itwill be used. That is to say that this final 10% of the product design process involves looking atwhat the customer expects from the product.

If we look at the quarrying industry, one of, if not the, major concern of any company in theindustry is to ensure that the product performs to the required level (ie: it can process theamount of material required) while also eliminating downtime as much as possible. This ensuresthat production remains at an optimum level, therefore ensuring maximum profitability.

There are several steps that can be taken during the product design process to ensure thatthese goals can be met. In order to be able to appreciate what these steps are, productdesigners must first of all understand the specific requirements of their customer and not justfocus on the functional aspects of their product.

So, relating to the quarrying industry again, if one of the major demands of our customers is areduction in downtime to as close to zero as is possible, then how can we go about achievingthis?

In looking at this in further detail we can categorise all the considerations that need to be madeunder three headings durability, efficiency and ease of maintenance.

Durability

With any industrial machinery such as quarrying equipment, there are going to be wear parts.This is an unavoidable fact of life. The key to good product design is to understand what thesewear parts are and take steps to ensure that these parts will last as long as possible.


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This may seem obvious, but this is often where products can fail. All too often there is a focuson the initial cost of the individual product, rather than the lifetime cost of ownership andoperational cost. The major concern for some equipment manufacturers is what price will wehave to sell this product at? This very question involves an unrealistic comparison with thecompetition as the initial selling price is only a small part of the whole story.

The fault here does not solely lie with the equipment manufacturers, as the customer can oftenbe too focused on the initial capital investment, rather than the operational cost of the product.However, the onus here is for the manufacturers to be able to explain to their customers, whyover the lifetime of the product, their offering is actually a more cost efficient option.

Efficiency

If a customer has specified a plant that will process 150 tons per hour, their requirement is notthat the plant will process 150 tons per hour on day 1, but that it will still be processing thisquantity of material and producing the required outputs on day 100, and 200 and 300 etc etc.

Also, taking a complete sand washing plant as an example, the washing process requires alarge amount of water to feed the system. In the current global climate of reducing the use ofnatural resources, product designers should therefore be looking at ways to reduce the freshwater requirement of these plants as much as possible.

Both of these examples relate back to the discussion earlier in relation to the durability issue. Asstated previously, the emphasis here has to be on the lifetime cost of ownership and operationalcost of any product rather than on the initial capital investment. This in turn places a largedegree of responsibility on the designers and manufacturers of this equipment to ensure they

are capable of making the case for their product over others that may be available for a smallercapital investment, but from an operational point of view are actually considerably moreexpensive.

Ease of maintenance

A considerable amount of plant down time is due to the operational maintenance of the plantonce it has been installed. This is often an issue that is placed too far down the list of prioritiesby product designers.

The reason for this is that this is the boring part of product design. Designers like to be seen asinnovators, whose remit is to constantly develop new ideas. There can be no doubt that theseare definitely skills which we need to encourage and we will always require.

This part of product design does not require any great innovation or creativity, but rather a welldeveloped understanding of how the plant will be used, how it will work and how the customerexpects it to work.


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How can product designers ensure that they keep fully aware of any features of their productsthat require further development? The answer to this may again seem fairly obvious, but the keyis communication.

Who understands how the product works on a day to day basis better than anyone else? The

operators on site who are responsible for ensuring that the plant remains operational for asmuch of the working day as is possible.

Surely then, it is essential that product designers ensure that a dialogue exists with thesepeople, who can point out any problems they have, or indeed make suggestions on furtherenhancements to the product that will make their lives easier and reduce the amount of timespent on day to day maintenance.

Practical Examples

Having spent some time looking at the various elements of product design that turn a goodconcept into a fantastic product, we can now show practical examples of how the approachadvocated here can make a real difference. What follows is a look at some individual pieces ofequipment used in the quarrying industry, with specific examples of how this approach has beenput into practice.

Feed Hopp ers

Ensuring that this equipment can be easily maintained is essential. This can be achieved byfocusing on a number of different aspects of the design process.

The first of these relates to the health & safety guards on the product. This supports the earlierpoint that designers must retain a focus on how the equipment will be used, as well as how itwill perform.

If we can design the guards in such a way as to ensure that it is a one man job to remove themwhen maintenance is required, this will help save time on site, and ultimately result in higherproduction levels.

Also, we should ensure that once the main guard has been removed, all the main maintenancepoints can be easily accessed. This responsibility falls yet again with the product designers.They can ensure that all of the relevant maintenance points are centralised as much as possible

saving time spent on maintenance and therefore ensuring maximum production

Another aspect of hopper design that should be considered is the localisation of the variousgrease points on the equipment. With all of these grease points being located in one area of thehopper, it not only saves time during maintenance, but also goes some way to ensuring thatnone of these grease points are missed. This therefore reduces the liklihood of problems beingexperienced with the hopper as a result of gaps in the maintenance regime.


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Screens

The design innovations dealt with here can be categorised under the heading of maximisingefficiency and there are a number of areas in which this can be achieved.

The first deals with ensuring the maximum open area on screens. The % of open area on thescreen is one factor that directly limits the tonnage on a screen and the dewatering capability ofthat screen. Therefore, if product designers can ensure the maximum open area on theirscreens, the direct result is a more efficient product, which leads to higher performance andultimately, greater profitability for the customer.

The next issue in relation to screens deals with vibration control. It is essential that screens usethe energy generated in vibration in the most efficient way possible. This can be achieved by thechoice of material to be used to harness the vibration.

Rather than using the commonly used steel springs, rubber marshmallows can lead toenormous efficiency benefits. This innovation alone prevents approximately 94% of vibrationsbeing transmitted to the supporting structure below. This represents good design for tworeasons.

Firstly, there is lower fatigue stress in the supporting structure as a result of a dramaticreduction in oscillating variable stress one of the major reasons for part failures.

Secondly, and even more importantly, energy is conserved in the screen and thereforetransmitted to the material on the screen. The result of this is more kinetic energy and higher

particle speed which results in better dewatering of the material passing over the screen.

Yet again, the ultimate result of these innovations is increased efficiency, higher production andgreater profitability.

Sand Plant

One of the major problems with a sand plant can be the loss of fines to the ponds. When this ishappening, material that can be processed and sold is effectively being written off as waste.

What can be done to maximise the fines recovery in the sand washing process? Theintroduction of hydrocyclone technology is the most efficient option available for anyoneinvolved in any form of sand washing.

This technology will effectively eliminate the loss of fines to the ponds, which results in moreproduct to sell, and greater profitability. It is also possible to set the sand plant up to recoverwhatever fines you require, which ensures that it can be used for a wide variety of applicationsincluding the production of speciality sands such as that specified by the USPGA for use in


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bunkers. The use of hydrocyclone technology coupled with an effective dewatering screenproduces dewatered sand with a moisture content of between 12% and 15%.

Spillage contro l

In any attempt to maximise production, the issue of spillage control must be addressed. Thereare a number of design innovations that can be introduced throughout the plant to ensure thatspillage control can be minimised.

The first step in reducing spillages is allowing for the conveyor belts to be scraped. The problemthat arises here is with the actual scraper itself they are not suited to the specific productbeing processed. The type of scraper required to prevent a build up of material will varyaccording to the nature of the feed material.

The first solution we can offer here is a design that allows for the scraper to be changed easily,to cope with changing feed materials. Scrapers of differing specifications can then be applieddepending on the material being processed for the most difficult material tungsten carbide canbe used to guarantee long life and prevent spillage issues.

The second solution to the problem of spillage control is to ensure that there is somemechanism for the scrapers to be washed. A spray system can be installed on all conveyorswhich will allow this washing process to be carried out regularly. This will reduce the build up ofmaterial that is responsible for spillage problems.

The final solution here can be defined under the heading of transfer point technology. This iswhere designers ensure they have a rounded understanding of how each individual piece of

equipment on site will interact with the other equipment it comes into contact with. At eachtransfer point, there will be different issues to address. It is essential that all these transferpoints are dealt with individually rather than collectively. If there are different issues at eachtransfer point, they will require different solutions also. The result of this is a synergy where allproducts work in harmony with each other.

The key here is to ensure that in designing all of the individual components of a full plant, thereis a focus on modularity. The product designers must ensure that all the individual pieces ofequipment are designed with one eye on the equipment they will connect with rather than allbeing designed individually and then thrown together in the hope that they will work.

Use proven technologies

The final aspect of ensuring maximum performance of your equipment lies with the type ofcomponents used on the equipment. It is in this area that manufacturers can all too often slip, asthey retain a focus on the initial selling price of their product, rather than the lifetime cost ofownership.


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Obviously, by using world renowned technologies and components, the initial selling price of theproduct will rise. However, over the life cycle of the product, this will actually work out as themost cost efficient option for the customer.

An example of this is the choice of pump used. In this area, Warman are widely regarded as

offering the best technology available. They have conducted extensive testing of their pumpsunder many applications and have a proven track record in terms of the performance of theirproduct. They have introduced several design innovations to ensure the long life of their pumpsincluding the use of hot bonded rubber as a lining.

Also, the use of materials such as chrome molybdenum for blades on a log washer effectivelyensures that this is no longer a wear part, such is the durability and strength of the material

Finally, cyclones are subject to heavy abrasion at certain points. One way to tackle this is todesign the cyclone as a collection of smaller sections rather than in one piece. This ensures thatonly the worn section needs to be replaced, rather than the whole cyclone.

Conclusion

A clear understanding of how the product will be used is perhaps the most important tool thatdesigners can possess. This is central to good product design. There are numerous exampleshere of small changes and innovations that can be made to ensure that any plant performs to itsabsolute maximum. The key to success is a focus on the customers main requirements theplant must perform to maximum efficiency, ensuring maximum production and guaranteeingmaximum profitability.

ALL OF THE DESIGN INNOVATIONS DESCRIBED IN THE ARTICLE CAN BE FOUND ONTHE EQUIPMENT OFFERED BY CDE IRELAND LTD. CDE DESIGN AND MANUFACTURE AWIDE RANGE OF EQUIPMENT FOR THE QUARRYING, RECYCLING AND WASTEMANAGEMENT INDUSTRIES AND OFFER A FULL TURN KEY SERVICE INCORPORATINGDESIGN, MANUFACTURE, INSTALLATION, COMMISSIONING, PROJECT MANAGEMENT,

AFTER SALES & SERVICE.

CONTACT DETAILS;CDE IRELAND Ltd, BALLYREAGH INDUSTRIAL ESTATE, SANDHOLES ROAD,COOKSTOWN, BT80 9DGT; 028 8676 7900 F: 028 8676 1414E: [email protected] W: WWW.CDEIRELAND.COM

Designing for Efficiency

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