Pt 3 of Cavitus’ Ultrasound Prototype in Winery Trials
Ξ October 30th, 2008 | → 0 Comments | ∇ A Day at a Time, Interviews, Technology, Wine News |
In this final post concerning the revolutionary innovation of ultrasound for use in barrel cleaning, we may read below Andrew Yap’s breakdown of the step-by-step processes the beta prototype performs. And of the surprisingly low labor requirements. I must say I was impressed by his program. Should you read all three posts, imagine the water savings alone by using the Cavitus system. And imagine the extended life of oak barrels, increasingly expensive if French. Fewer trees might be felled, no small matter. Indeed, energy and resources are saved at every turn with the employ of high power ultrasonics. Whether it is ‘green’, I’ve yet to crunch the numbers. But I am encouraged.
Admin What size winery is the unit designed for?
Andrew Yap For the first unit it is for wineries that have at least 5000 to 7000 barrels to get a return on investment within 24 months. This is the average. Many wineries think this is pretty good. To get a return on investment on capital equipment is usually around three years. To get it back within two years we think is a pretty good deal. But of course, that is for this equipment, Wineries may decide they want to use selective components to retrofit into their systems.
Now, this is only a one-head system, so you clean one barrel at a time. Although you’re cleaning one barrel at a time the maximum time is only governed by the time you take to sonicate that one barrel. When the barrels come along the conveyer one is being filled, one is being sonicated, and one is being emptied. There are wineries that want to have a four-heads at a time. They can do more barrels in the five minutes required for sonication.
If I’ve read your paper correctly one of the advantages of ultrasonics is the uniformity of brett destruction/inactivation as opposed to high pressure hot water treatments.
AY Yes. That’s because the spray system does not target every spot within the barrel. There are various systems in operation, the main one, the static one, has a rose-like appearance which chucks water into the air and you hope that it will hit every part of the barrel. But it doesn’t. With the rotating head type they are a bit better than the static spray. I must point out that in Australia when we talk of ‘high pressure’ we are talking about 1000 psi to 3000 psi. Here in the states it is more common for wineries to use 100 psi. Our trials are at 1000 psi. If brett cannot be killed and tartrates cannot be removed at 1000 psi at 60 degrees centigrade then you can imagine what 100 psi does. Unless you clean your barrels several times a year, which some wineries do to maintain cleanliness. That’s fine but one of the concerns with winemakers is if they apply 1000 psi or 3000 psi you can remove off-flavor compounds. Now, we’ve already shown that at 1000 psi that doesn’t happen. At 3000 psi, some wineries in Australia do that, the smooth surface actually becomes furry after such a treatment.
Essentially destroying your barrel. And multiplying the surface area for spoilage bacteria, yeasts…
AY Yes, yes. Their argument is that they get an absolutely clean barrel (laughs) at the expense of ruining the barrel!
And all toasting must also be gone.
AY Yes. And in terms of hot water, I forgot to mention to you that we heat the water to 60 degrees centigrade (140 fahrenheit). We’ve found that 60c combines well for cleaning and killing the brett. In fact, both can be achieved at 50c, there’s data that shows that, but if you only wanted to clean and not kill brett then 40c is quite adequate with high powered sonics. So the high powered ultrasound works quite well at 40 to 60c. But if you want to kill the organisms at the same time as cleaning then what you want to do to ensure that the temperature is adequate for both processes.
About the power output?
AY In our previous lab trials we were using small units, about 10 to to 50 watts, but our unit here is 4 kw. Here we are talking about 225L, so the larger the volume, the power per ml, that is what is important. The larger the vessel, 225L versus puncheons, which are 400L, you need either to have the barrel sonicated a longer time or have a more powerful unit in place. The reason we’ve chosen a 4 kw unit is that the larger the unit the thicker the sonotrode, the rod you insert into the barrel bunghole. If it becomes too large it won’t go through the bunghole. An 8 kw unit would shorten the cleaning time to two minutes but the sonotrode would not pass through the hole. There is no manufacturer who can do that.
Will you be at the Unified Wine and Grape Symposium this year?
AY Yes. For people interested in looking at the technology we will be at the Unified, a booth there, and we will have a warehouse in Sacramento, we’re not sure where, we’re looking for one. If you know of one let us know. We will put this unit there so people can come along and have a look at it on the exhibition days. They may see it in operation. We’ll take barrels, open them up so people can see what they are like before cleaning, and after cleaning we’ll open them up again. If people want advance information they can email me and I will provide them with the date and time, the place where the demonstration will take place.
Will you be in attendance?
AY Oh, yes.
So, may we walk through the unit in all its stages.
AY This is the full unit. It is designed to have all the components for the system to work independently of what the winery may have. It has all the bells and whistles. It contains the hot water heater, the filtration system so the water can be recycled 40 times. Indeed, there’s a lot of energy savings because you only have to heat the water once, to 60c, and then it is maintained at that temperature.
Now we see the conveyer system, where the barrels are introduced, from the right hand side. The movement of the barrels is all automated. As they go through the door they go through filling and then sonication. This is the prototype. Four sonicating heads may be added, as well as other modifications, for puncheons, for example. The customer will be free to determine what size barrels they would want to clean. The proper equipment would be provided.
Here you can see the sonotrode going into the bunghole, and on the right you see the barrel being filled. The red hose introduces the 60 c water into the barrel. We set up this system whereby the water level is predetermined, it will stop filling automatically when the proper level is reached. The sonitrode is introduced through the bunghole and into the water. Any water lost will be topped off using the blue hose which you can see on the left side. Water must be all the way to the top where the opening is because this is an area where brett infection is usually very pronounced. Because the barrel is completely full you would get cavitation bubbles right throughout the volume of the water, in every nook and corner. The barrel would be fully cavitated. There would be no escape for any micro-organism present in any part of the barrel, either on the surface, subsurface or in the pores.
The water is then drained from the barrel into a trough from which it is the sucked into a recycling tank and goes through a membrane filter and the filtered water goes back into the water tank and reheated back to 60c. Normally the temperature of the water after sonication is probably a degree or so below 60c. Very little energy is required to bring it back to 60c.
The last hose dangling is for water to remove any debris sticking onto the walls of the barrel. The remaining debris would be just tartrates. Any yeast cells would be dead. We recommend giving it a quick spray.
The unit may be run single-handedly, the whole system. During the sonication time, about five minutes, he can load more barrels and take off the clean barrels. The filling time is only about two minutes, and emptying takes about one and a half minutes.
This model is not the most refined for any particular winery but it is a ’stand alone’ model. It can be bought by a winery which is without reverse osmosis water, or a filtration unit, or a hot water heating system. Larger wineries may want to retrofit ultrasonic units into their system. And with four ultrasound heads, for example, you could clean four barrels in five minutes.
Can a Tom Beard system be retrofitted?
AY Yes. As you know Tom Beard systems already have four spikes that will clean four barrels at the same time. They come from underneath. So to replace this all you need to do is standby for a processing unit with four sonitrodes. Four barrels can be then be sonicated at one time.
Thank you, Andrew, for your time. Have a safe flight home.
AY Thank you, Ken.
Admin.
