Conditioning as part of the pelleting process

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					                                                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

                                                                                                                                                                                                                                             ing “first-in,

                                                                                                                                                          MADE IN HOLLAND                                                                    first-out”,
                                                                                                                                                                                                                                             were      ripen-
                                                                                                                                                                                                                                             ers; a kind of
                                                                                                                                                                                                                                             cooking vessel
                                                                                                                                                                                                                                             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,
                                                                                                                                                                                                                                             optimisation and
                                                                                                                                                                                                                                             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
                                                                                                                                                                                                                                                                             chan die
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
                                                                                                                                                                                                                                                                                            355 k
   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,
   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
 F: Conditioning

                                                                                                                                                                                    GROWiNG iS
                                                                  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                                                                                            -
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Description: While conditioning is a process that has kept the attention of the modern feed milling industry for some time now, the pelleting process of press meal is a subject that is no longer considered to be very important.