May | June 2011
Feature title: Conditioning as part of the pelleting process
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The International magazine for the aquaculture feed industry
F: Conditioning F: Conditioning
MADE IN HOLLAND first-out”,
ers; a kind of
which has been
in the feed mill-
ing industry for
over 20 years and
in many varieties.
The main concern con-
when using the ditioning
ripeners in the feed temperature and
milling industry is the formulation.
contamination but The temperature level can be varied
when much longer according to the retention time in order to
conditioning times avoid destructive effects on the nutrients
AL30O (that is >4 minutes) in the feed (that is protein de-naturation).
are required, the Whereas the formulation has an influence
AD System High capacity extruders ripeners are still a on the retention time meaning that the
and expanders. valid option. optimum availability of nutrients in the feed
As already stat- can be reached as well as optimising the
ed the conditioning physical quality of the pellets.
process is about Recently other aspects have had to
as part of the pelleting process Almex b.v., Verlengde Ooyerhoekseweg 29, 7207 BJ Zutphen, The Netherlands
tel. +31 (0)575 572666, fax +31 (0)575 572727, e-mail email@example.com, www.almex.nl
therefore the time
factor is mainly
be taken into account due to consumer
concerns, for instance Salmonella. Also this
needs to be considered and treated in the
determined by the conditioning process.
by Harold Schroijen, Van Aarsen International, The Netherlands
hile conditioning is ture and pressure. Pressure is only used in being used. Besides steam quality, the influ-
a process that has unconventional processes where expander ence of the humidity of raw materials as
More than 125 years world's leader in produc tivity
kept the attention or extruder techniques are being used. well as the feed composition are of great Since 1883
of the modern feed In the conventional conditioning process, importance.
milling industry for some time now, only time, humidity and temperature are Steam quality and steam quantity control
the pelleting process of press meal is applicable. are subjects enough alone to warrant fur- Roll
a subject that is no longer considered Whereas in the past the aim of con- ther discussion, however, in many practical The best value package with speed t
to be very important. ditioning was to optimise the pelleting cases, steam quality and steam control Measu
process, nowadays it is much more the are subjects that are not usually given the the lowest cost per tonne
It needs to be understood that feed intention to optimise the nutritional and attention they need in order to optimise
milling is about the balance between the physical quality of the feed. the conditioning process.
different processes being used. As one When using the variables in the conven- As temperature and humidity are
process is linked to another, it is difficult tional conditioning process, it should first strongly related, the actual variable available
• Long term conditioners, Hygieniser Quic
to discuss only one process without having need to be understood that temperature in a conventional conditioning process is
to take another into consideration. I plan a and humidity are related as steam is gener- time. It should, however, be kept in mind
discussion of two processes, which interact ally used to increase the temperature of the that the conditioning process is an optimi- • Remote roll adjustment, Lineator clam e
frequently with one another and also with press meal. sation and not a maximsation.
all the other processes used in the feed Furthermore, there is also a maximum Where single conditioners were a com- • Roll speed measurement
milling industry. level of humidity of the press meal in order mon choice for quite a number of years,
to avoid blockages of the pellet press. In now double and even triple condition-
Conditioning general it can be said that the maximum ers are being used prior to the pelleting • Hot start mixer
Conditioning is a process in the feed percentage of steam that can be added to process.
milling industry, which takes place from the press meal is approximately maximum Conditioning times lasted, in most cases, • Quick die change
intake to out-loading. five percent and for each percentage of less than a minute and more importantly
However, in many cases when referring dry steam added, the temperature of the these types of conditioners did not guaran-
to conditioning, it is the treatment of press press meal will increase by approximately tee the “first-in, first-out” principle.
meal prior to the pelleting process that is 15 deg C. For many years, the only conventional
meant. Of course, the steam quality is influential conditioning process that could guarantee
CONTACT CPM/Europe BV Distelweg 89, 1031 HD Amsterdam,The Netherlands Phone +31 20 494 61 11, Fax +31 20 636 42 94, firstname.lastname@example.org
Conditioning of press meal is a process and the above mentioned values are only a given time and that extended a maximum
with the variables time, humidity, tempera- applicable when a good quality steam is retention time of one minute, while also HIGH PERFORMANCES LOW COST MAINTENANCE MAXIMUM SAFETY LONG LIFETIME WWW.CPMEUROPE.NL
40 | InternatIonal AquAFeed | May-June 2011 May-June 2011 | InternatIonal AquAFeed | 41
Time Conditioner, facilitating course, is related to the capacity of the
the control and the required pellet mill.
height is easily a few less Therefore, when comparing dies, the
meters. All these features have aspects that need to be considered are the
been integrated into one con- types of material to be used, the hardness
ventional conditioner, which is called and whether surface hardening or complete
the “Conditioner LTC”. hardening will be used, the number of holes
For a standard control a PLC or the open area surface (OAS) and the
is integrated into the pelleting line wall thickness of the die including possible
control system and for a more counter-drill.
sophisticated control a PressM@ When discussing capacity, using the same
nager, the Van Aarsen pelleting line formulation and the required pellet quality,
automation based on remote I/O the die surface of the pellet mill (with the
with intelligence (meaning the system same OAS) and the die thickness are the
is capable of achieving even higher goals major factors influencing capacity. These
Therefore, than a well-trained pellet mill operator). together with the drive installed, determine
the new generation of con- the KW per cm2, which is a factor to be
ventional conditioners (without using Pelleting considered when researching the opera-
pressure) are focussing on the variables After conditioning of the press meal tional costs.
time, temperature and humidity where either the mash is cooled when heat- Practical trials carried out under 100
time is maximised to four minutes at treated mash is required (for instance percent identical circumstances, have indi-
temperatures of approximately 85 deg breeders) or, in most cases, the pelleting cated that differences in operational costs
C and capacities of up to 20tph. These process starts. among different types of pellet mills can
types of conditioners should guarantee a The pelleting process also has an effect vary up to EUR50,000 per year which are,
“first-in, first-out” while also guaranteeing on the nutritional as well as the physical of course, significant figures, but realistic
retention time. The principle is rather quality of the feed. Experience has shown nevertheless.
simple as generally the feed is brought up that it is not only the capacity of the pellet Van Aarsen pellet mills are well know for
to the required temperature by means of mill but the formulation, die specifications their design criteria, a huge die surface and
steam and subsequently transferred into a as well as the required pellet quality are also low die speed so that an acceptable capacity
large screw conveyor in which the speed aspects that should be taken into account. is reached while still maintaining focus on
of the mash is determined by a frequency Where a Van Aarsen C900 is producing pellet quality (which is also influenced by
controller. The screw conveyor is steam or 45tph in South America, the same machine the retention time of the press meal in
electrically heated and insulated. is capable of reaching a capacity of 18tph in the die).
So, by means of the filling degree and the a Dutch environment.The big difference can This, of course, combined with an inter-
frequency (at a certain pitch of the screw), be explained by formulation, die specifica- mediate drive allowing the possibility to
retention time can be guaranteed. tions and the required pellet quality. Also a change die speed relatively easily (changing
For those involved with feed milling proper conditioning process influences the a small pulley) without installing frequency
practises, it is well known that there are a output of the pellet mill. controllers for the generally larger drives
few concerns. Firstly, the height of installa- However, the figures above are based on used on pellet mills. Furthermore, large roll-
tion for this new generation of conditioners the same conditioning process. er diameters create a small angle between
is not often available. For this reason, Van Of course, the pellet mill has a number the die and the roller, which compacts the
Aarsen International BV in The Netherlands of variables that can be used to optimise feed smoothly before forced it into the die.
is able to position the conditioner beside the process. Of course, variables differ when using
the Long Time Conditioner (LTC). These variables vary from speed of the pellet mill for traditional, untraditional
The second concern is the control of the die to hydraulic roller adjustment and or aqua feed but the principles remain the
the pelleting process because the long should only be used when the influence of same. As circumstances differ constantly,
retention time leads to a delayed reaction these options are thoroughly understood only general guidelines can be provided
of the pellet press on changed variables. by the operating personnel. except for when detailed information is
This complicates the matter even further This practical know- how could also available and a custom-made solution given
due to the fact that the pellet mill cannot be be delivered by an intelligent pelleting line by those in the feed milling industry with
fed directly from the retention time screw. automation system such as PressM@nager. both feed on the ground.
Some suppliers therefore use small This system is capable of combining the The global go-getters of Van Aarsen are
intermediate bins between the retention different variables in order to optimise the always ready and willing to assist in optimis-
time screw and the pellet press with a feed- process. ing a processes, resulting in higher returns
ing screw for the pellet press below the bin, However, before continuing the pelleting and more ease in operation.
FRANCE / 00 33 2 97 40 42 09
FRANCE / 00 33 2 97 40 42 09
leading possibly to contamination as well process, a small note needs to be made
as loss of temperature. Once again more about the dies being used.
height is required and control becomes As dies of reputable suppliers are gen- More inforMation:
even more critical to maintain due to the erally all of the same material, which is Van Aarsen International Our hydrolysates have a superior concentration of Natural Active NutrientsTM
use of buffer bins. completely hardened, difference is gener- P.O Box 5010 Thanks to their biological action on fish and shrimp growth mechanisms,
In order to avoid this, Van Aarsen has Heel, NL-6097 ZG THE NETHERLANDS
ally found in the open area surface - OAS
they boost your feed performance and help you substituting fish meal.
integrated a feeding device in the Long (that is, the number of holes), which, of
42 || InternatIonal AquAFeed || May-June 2011
42 InternatIonal AquAFeed May-June 2011 email@example.com - www.aquativ-diana.com
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