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Thursday 30 August 2012

TEST TEST TEST - Analyse

An essential element of product development is the testing which establishes the characteristics of the device.  Sometimes the required testing equipment has its own limitations or is too expensive for only limited use.  Tools such as oscilloscopes and DAQ (Digital Acquisition Boards) have many applications and are of great assistance in observing short duration or rare phenomena.  

Simultaneous DAQ boards are nice because they eliminate channel skew but they are more expensive because each channel requires its own A/D converter.  I like Labview but it is frightfully expensive which means it has not been updated for many years.  An additional problem is that the program cannot be downgraded which means if you started with a deluxe-o-matic Suite then the upgrades will approach the cost of purchasing Labview.

It is possible to be creative and resourceful when selecting sensors but often it is a quick and dirty solution that yields the equivalent data.  Non-calibrated equipment can be misleading therefore some reference measurements should be done to develop a "feel" for the measurements.  There is little that is worse than making decisions based on faulty data.

One day I'll be brave enough to look into the new mini computers such as Arduino, Rasberry Pi, etc.  These devices have daughter boards with surprising capacity.  In addition to monitoring the tested device it is possible to also actuate devices.  So far the use of the digital output has only controlled solenoid pneumatic valves and solid state relays.  Not a sign of great imagination!

One handy improvised device was a "Magic Wand" which was essentially a meter stick with a piezzo film bonded card slotted in to the end.  It saved fingers from having mishaps with moving equipment when measuring pump strokes, checking vibrating structures, or simply establishing start/stop time.  An Infrared transmitter/receiver and a 9 Volt battery makes an inexpensive tachometer.  Coils are very handy for measuring current especially when coupled with a data acquisition system.  It is handy to know the start up amperage when testing various rotors and speeds.

The Blower output can be measured in many ways i.e. anemometer, rotameter, venturi but most of them can only be used at relatively low temperatures.  Our high temperature Blower required a metallic venturi which does present some fabrication challenges since the smallest diameter is the furthest from the opening which is not ideal for cutting a smooth wall.

Darn, that was mostly about testing, the analytical part will have to be postponed.

A cup of freshly roasted coffee is a great time saver akin to measure thrice - cut once.

Tuesday 14 August 2012

High Pressure Hot Air Blower - MTBF or Down Time?

High temperatures are not conducive to the longevity of rolling components therefore the conventional ambient blower components have the lifespan of a firefly when used at elevated temperatures.  It is almost a universal mechanical truth that items used at higher temperatures have a reduced working life.  It does not mean that durability is impossible.  It means that durability has to be a priority in the design stage and that components are selected based on their ability at surviving in a high temperature environment.

The focus has been on improving MTBF (mean time before failure) but an alternate viewpoint was raised by a "person in the know".  Essentially the comment was that MTBF is important but "down time" is also a critical factor.  Both of these constitute the inconvenience factor for the client especially if one is low and/or the other is high. 

The insulation required for high temperature equipment does not facilitate repairs therefore the selection of these materials is as important as the blower design itself in facilitating a speedy repair.  With this priority in mind there has been a move towards a faster turn around if a repair or maintenance is required.  The redesign is ongoing and alternative solutions are being tested.

Temperature is but one of the challenges.  We are currently testing blowers that are more tolerant when placed in an environment of "nasty" or corrosive gases.

It is doubtful that the maintenance or repair turn-around will approach Formula 1 tire changing experiences but it promises to be a significant improvement.  It does help to have a crew of 12 to undertake the maintenance if there is sufficient room for everyone to do their task.   It is not likely that such a crew will work unimpeded around a blower therefore it will take longer to affect the change but wages and costs will be lower.

Personally I prefer to take a little longer especially if there is a window of freshly roasted coffee reflection to organize the task.

Cheers,

Sunday 5 August 2012

Does Extreme Processing Enhance Food visually or nutritionally ?

AKA - Does Processing make it a Lesser Food ?

There is an older blog that has largely gone unread, yet this is a very important topic that affects every ones health.  Is it a lack of interest, poor title, or is it not showing up in the Search Engines ?

The distilled opinion is "the more you process the less the consumer receives".

For various reasons the most common vehicle for food delivery has been perverted.  In response to "manufactured food", fresh food advocates are informing the public about  real food and real food costs.  My assumption is that to benefit from processing the end user must have the same objectives as the processor.  Very often they will share the visual objective but that is often irrelevant to nutrition if not detrimental.

Living on the 100-Mile Diet , Revisiting Carrying Capacity:, Natural Foods, Organic Foods, etc.  It appears that greater "inputs" yield less nutrition.  Large marketing budgets promote convenience and "filling the belly" instead of feeding the body for growth and health.  Increased time spent transporting food means, as well, increased food degradation time.  Industry will typically attempt to address product appearance indicators that influence a consumer.  Unfortunately nutrition is sacrificed for the sake of colour and appearance.  


Before focusing on one product not usually covered in the fresh food debates I would like to add that I believe that the movement advocating quality food is gaining membership.  

My interest is the freshness of coffee.  Of course people do not live by freshness of coffee alone.  That would be silly because it mostly feeds the soul, the well being, the disposition, etc.   Well there have been countless studies about the benefits ...   Coffee has undergone a centralizing process which exchanged convenience for quality.  Bigger is not better if the product is lessened.  We have not developed Star Trek transporters to move food instantly to the consumer while maintaining the product integrity.  If the past is any indicator this futuristic device would further degrade the food.  Warehousing roasted coffee decreases the value to the end user.

I advocate that the coffee roaster, grinder, espresso machine, and brewer should be at the same site.  Nothing gives more credibility to the freshness of the product as when the consumer can observe the preparation.  To this end Jim Townley uses the moniker of "the Theatre of Roasting".  It encourages clients to learn about the process while it reinforces the artisanal qualities of freshness and caring preparation.  Small batch roasting, in our case 3 kg batches, allows the RoastMaster to roast the requirements of the next few days.  Most likely more than one batch of each coffee will be roasted but that is a choice based on sales.

This is a simple food preparation model even though it appears to counter the produced locally mantra of some of the above links.  We are not blessed with local coffee plantations but because the coffee bean is a seed which is designed by nature for long term storage it may be consumed at a distance from its origins with a certain proviso.  So where is the Freshness Challenge?  Roasting transforms the bean and creates havoc with the storage capability of the bean.  Roasted Coffee degrades quickly despite touted storage "solutions".   Freshly ground stale beans is an advertising distraction which offers no benefit to the consumer.  The analogy of the weak chain link is true.  Nothing will resurrect stale coffee not even a marketing campaign.  

For the best cup of coffee start with a freshly roasted high mountain grown Arabica bean that is ground just before brewing.