Generation-4 solarola cyclic kiln, Melbourne Australia

Solarkilns has commercially owned and operated its own kilns for long periods during its Research and Development phase of 15 years to test and prove the capabilities of our kilns you see today. This hands on approach has provided many benifits in the development of this technology based on real life experience.

It was evedent very early on in the development of the kiln that our superior collection and insulation systems produced exceptionally large and consistent amounts of heat energy input into the kiln from the sun. To prove the benifits it was around the mid-phase of our development (2005’06) we used unparalleled data capture facilities and the resulting analysis enabled us to fine tune the control system operation developing our "Cyclic" drying methods to work in harmony with the natural daily cycles. 

The following novel and mostly patented controller features are some of the many controller characteristics that clearly distinguish Solarkilns from other inferior systems. This explains why Solarkilns technology delivers superior results in many locations. Generally speaking, Solarkilns technology “makes more from less!”

-More products from less inputs, more energy absorbed from the sun and converted to hot air.

Solarkilns energy management features combine with important and often discreet elements of the kiln design to better control the variable climate and solar energy conditions so that risk of degradation and fungal attack in many products from timber to dried foods and herbs is greatly minimised.

All or most of the following unique features are included in all of our controller types including cyclitrol.


DUAL SCHEDULES (NIGHT & DAY)

Solarkilns controllers are cyclically enabled. Our controllers are the only known cyclic dryer systems available in the world today. The operator system includes 2 (or more) sets of optionally and automatically applied drying schedule conditions for example for day and night conditions. Typically, a more severe set of conditions is applied during the day than at night, in order to enable different rules to be applied to the drying process when energy is abundant during the day and when it is finite at night.

These features underpin other controller functions that follow, enabling a solarkilns dryer to operate more consistently and reliably in order to overcome problems of excessive humidity and fungal attack or simply to avoid stress and case-hardening.

These features also have an important role in energy management, enabling the conditions to cycle in a very controlled way so that finite energy trapped in the load can be used to maintain core-level drying  and so that moisture can be redistributed from the wettest to the driest sections of the load during an active night of operation.

This constant monitoring of both the outside and kiln internal conditions means Solarkilns keep working while you sleep, automatically making the most from the enviroment which means you can be contented that Solarkilns technology is still working at improving your kiln load and increasing your profits.  

MULTI-FUNCTION AIR HEATING SYSTEM

Solarkilns controllers include systems that change the function of the solar collector to insulation mode when cloud and sunlight conditions are at their lowest. In practise, this means that the controller creates a second double-glazed insulation boundary to compliment the permanent insulation cavity created by the outer cover system. Combined with the superior rounded shape of our collection system that produces more heat from morning and afternoon sunlight, this superior insulation system means that Solarkilns generally have “energy to burn”. In some instances, Solarkilns commonly deliver as much as 14 times more heat energy for the same footprint of other flat-collator type solar kiln designs.  

MULTI-LEVEL OVER-TEMPERATURE CONTROL

Solarkilns controllers operate several levels of over-temperature control in order to limit excessive levels of temperature inside the kiln so that your products are protected from excesses that may cause degrade to your products.

SOLAR BANKING

During our long experience we have found that higher than normal operating temperatures are not detrimental to quality outcomes when combined with superior night time stress relief periods, indeed this practice overcomes the stress that short periods of high temperature will otherwise cause. Solarkilns controllers have an optional system that allows the operator to set a maximum temperature that governs when the controller will go into over-temperature mode.

This temperature may be for example optionally set at 60 deg C when the set kiln temperature may be for example 40 deg C. A supporting heater (if fitted) can maintain set temperature until solar heat becomes available to potentially increase the kiln temperature to the maximum setting.

Apart from increasing the rate of diffusion inside the material being dried, this otherwise excess energy is stored inside the material so that there is adequate heat energy to maintain drying overnight and often into the following day that could be rainy and overcast.

This feature means that Solarkilns operate when others cannot and when they do so they operate more effectively in terms of transport of moisture from the inner parts of a product and also have more heat to manage.

When Solarkilns are storing energy, others simply raise the white flag and wait for another sunny day that is hopefully not too far away. Even then, they have missed the opportunity to accelerate core drying, to optimise the night reconditioning effect and to make higher profits.

SMART VENTING

Other lesser kilns regularly encounter times when it is not appropriate or practical to continue to vent moisture laden air towards the operator set-point. Of course, venting not only exhausts water, it also exhausts valuable heat energy with it. We have found this to be very wasteful and akin to “throwing out the baby with the bath-water”; most importantly, it puts materials being dried at high risk of fungal and mould attack.

The most common time when this problem occurs for inferior kilns is after a summer or tropical cloud-burst and when ambient humidity goes to its most extreme levels. The next most common time is in the mornings when the inferior kiln returns to ambient temperature after a night of unregulated venting where heat is lost via “dumb-venting” or due to poor insulation. Without this feature, solar kilns simply cannot perform well in tropical and high humidity climates.

Solarkilns controllers incorporate an ambient weather station and complex automated functions that constantly compare the comparative ambient and kiln absolute humidity levels. Four different systems precede our current state of the art system that now effectively overrules the operator setting when it detects times that the volume of moisture of air (grams/ M3) in the ambient air exceeds the volume in the kiln air. An optional operator setting tells the controller how many percentage points, for example 30% more water is required in the kiln air for venting to be activated.  The controller react by stopping venting short of the control set-point to enable the adverse weather condition to pass or alternatively for the kiln to have sufficient time to accumulate sufficient extra heat to become light enough to carry more water. In this way, it is ALWAYS thinking for you in order to conserve energy. By so doing, Solarkilns controllers ensure that your kiln achieves more from less and produces more reliable and higher quality outcomes at all times.

In any event, inferior kilns regularly keep venting to levels that are practically impossible and lose the benefit of many of the positive drying dynamics that are essential for high quality results. 

TEMPERATURE PRIORITY (TP)

Is an optional operator function that enables the controller to apply other rules that govern venting in the interests of quality and efficiency. During night time operation, the kiln temperature setting is typically set lower then daytime.  TP when activated takes automated steps to govern venting to a point where a minimum required temperature condition has been reached in the kiln.

There comes a time every night where the available stored heat energy is capable of making a more valuable contribution by maintaining high levels of diffusion in the material so that moisture can be moved more quickly from the inner parts (core) of the material to the outer surfaces. It can then be quickly removed during the next day cycle. The alternative of achieving a slight increase in overall mass loss from your kiln load by venting during the cold of night is then of much lesser value to the overall process.

Here is just one more feature among many to manage your process better and, frankly make our earlier generation 1 technology and that of our competitors third rate by comparison.  

HUMIDITY RETARD (HR)

This feature is integral to smart cyclic drying and governs humidification into the night phase where our method encourages a gradual increase in humidity as opposed to the rapid increase found in inferior systems that do not have the benefit of 15 years of development.

A gradual change in relative humidity is a physical certainty for any cooling air. Our superior insulation systems combine with a variety of energy management features to GRADUALLY increase RH so that the driest sections of product gradually and progressively switch off as humidity increases so that energy is targeted to the wettest sections. This creates the ultimate stress relief mechanism by homogenising or equalising the moisture content of all materials and its constituent parts.  

VARIABLE SPEED FANS

When other inferior systems simply fail and ultimately wave the white flag at night and stop or continue to operate with no net drying effect due to lack of heat energy, ours keeps working. In most cases, our controllers make provision for 2, 4 or infinitely variable speed settings to achieve many things that others have simply not even discovered yet.

These systems and others related to it assist in mixing wet air from the parts that continue to dry at night so that it can be used to maintain drying, at the same time as transporting heat energy from the driest parts that have begun to reabsorb moisture.

In other cases, the speed and timing of fans may be set to produce the most desirable outcomes for distribution and use of heat energy and moisture in order to produce the best possible quality and process efficiency outcome.

SUMMARY

There is simply no other kiln controller system in the world to match Solarkilns. For all those who are now playing catch up and working with generation 1 technology similar to that which we sold in 1997, you would be well advised to ask yourself whether the pain and cost of failure that is inevitable is worth cutting corners in 2016.