ELIMINATING SALMONELLA IN THE FEED BY CONTROLLING CONDITIONER TEMPERATURE

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

CREATE AND EVALUATE A TEMPERATURE MONITORING SYSTEM IN THE

CONDITIONER IN PELLETED FEED.

Dhia AL-Chalabi*

* Department of Agricultural machinery and equipment- College of Agriculture- University

of Baghdad. drdhia@coagri.uobaghdad.edu.iq

ABSTRACT

This project has been conducted in New Zealand in 1999, as a

requirement for feed production companies to control salmonella in feed by

Ministry of Agriculture and Fisheries (MAF). Feed is the most important factor

in poultry production enterprises because of its impact on cost and health.

It takes the feed about two minutes to reach the 80 ºC. The feed could be

recycled if didn’t reach the 82-83 ºC planned. Steam temperature was stable and

around 130 ºC. This temperature could be optimized to reduce energy cost

without affecting the pelleting process through tracing the feed in temperature

(ingredients) one can say, that some of the steam is entering to the feed-in tube

and raising the feed-in temperature to 46-50 ºC. The regular incoming feed

temperature was between 20-25 ºC. The die temperature was 92 ºC, and cooler

temperature for the feed out was 20 ºC.
Key words: Feed, Salmonella, pelleted feed, feed temperature, conditioner temperature, poultry feed.

INTRODUCTION

Salmonella could be controlled in the conditioner when producing pelleted

feed for poultry (Broilers, Turkey) or other animals. Feed temperature control in

the conditioner is (Coony et al., 2010) one of the ways to eliminate salmonella

and other bacteria in the feed manufacturing process (Himathongham et al.1996)

practically and economically. The temperature range 80-85.7 C (McCapes et

al., 1988) is affective to kill bacteria in the conditioner (Lake et al.,2005). The

duration of the temperature is important as well (Africa Fernandez, 2003).

Increasing the temperature above this range may drop feed nutritional value

(Silverside, 1999) and may reduce the feed energy value (Creswell and Bedford,

2006). Increasing the retention time may affect the productivity of the feed mill.

Lower temperature could not affect bacteria present in the feed (John Payne,

2001). Therefore it is essential to know what temperatures are in the conditioner

(Peter Cressey, 2011), and or there are temperature differences in the

conditioner. Monitoring feed temperature in two locations (in and out) is not

enough to have a clear picture about the temperature in the conditioner. Because

ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ

Received for publication 27 / 10 / 2014.

Accepted for publication 5 / 4 / 2015 .

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

temperatures are usually varies from location to location in the conditioner

especially with unstable run. Suggested pelleting feed temperature above 85 C

should be avoided.

Types of conditioners and coolers

There are two major types of conditioners. The first one is that, the steam pipe

connection is from the topside as well as the feed in tube. The second type is

that the steam pipe is connected to the conditioner from bottom, and the feed in

tube from top. Both of them may have retention plate installed at the end of

conditioner cylinder.

In the same time there are two types of coolers as well. First type is the counter

flow cooler, where the air penetrates the feed from bottom to the top. The

second one is the tower cooler. The air comes from the sides and exits from the

bottom. Where the first one the sir comes from bottom and exits from top.

Objectives

1- Design and implement temperature monitoring system in the feed mill.

2- Monitoring the feed temperature in the die will not exceed 92 C.
3- Monitoring feed temperature inside the conditioner not the steam temp.
4- Access to the system from any location through the internet.
5- Display the data graphically and digitally by using Microsoft Office.

METHODS AND MATERIALS

This project has been conducted in New Zealand in 1999, as a requirement for

feed production companies and to Salmonella control from Ministry of

Agriculture and Fisheries (MAF). The temperature in the conditioner must be

82.2 ºC in all parts of the conditioner (Wong , 2003). The system has to give a

clear picture about the feed temperature during production.

Instrumentation

To monitor inside temperature of the conditioner, depending on the length of

the conditioner and the rotating mixing paddles inside the conditioner up to eight

probes are needed in different locations to adequately collect data without

damaging the probes. Locations of the probes are very important and critical to

understand what is happening inside the conditioner. Many activities need to be

clarified first; the connection of the steam pipe to the conditioner is one of them.

Some conditioners are connected at the top others at the bottom. Probes should

be placed in locations where the feed is moving, not the steam flow. This means

that we are measuring the feed temperature not the steam temperature. Figure 1

gives an idea about the locations of the probes. A data logger has been used with

46 channels, the data logger connected to the internet though out a modem to

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

monitor the temperature and the data from any place in and out New Zealand.

Probes used were thermocouples type T, installed though out the feed mill, to

the control room, where the data collected and used to verify temperature pattern

in all locations and to compare to the planned temperature according to MAF.

The probe locations are as follow: -

1. Feed temperature, measures the feed (ingredients) temperature in the feed
pipe connected to conditioner. (Probe 1 Figure 5).

2. Steam in temperature, measures the steam temperature in the steam pipe
connected to the conditioner Probe S.

3. Bottom right feed temperature. (conditioner)
4. Topside temperature to detect steam movement. (conditioner)
5. Bottom left feed temperature. (conditioner)
6. Bottom middle side feed temperature before exiting the conditioner.
7. Feed out conditioner temperature, feed exiting the conditioner.
8. Feed out the die temperature; feed temperature leaving the die to the

cooler.

Also we need at least 3 to 4 probes in the cooler to detect the feed temperature

entering and leaving the cooler. It is important to monitor feed temperature

going to the feed storage bins. The above-suggested locations will give a good

indication about the feed temperature and feed movement. Regarding to the

movement of the feed and the steam distribution of probes was critical to reflect

the correct and good mixing of the feed ingredients together and with the steam

coming to the conditioner without any separation.

Probe S will give us a clear idea about the steam temperature getting in the

conditioner. Some times the steam temperature varies or fluctuates, and we are

assuming that it is correct temperature.

Probe 1 will give the temperature of the feed ingredients coming in the

conditioner. This probe should always read lower temperature (20-30C),

because there is no heating done to the feed ingredients in previous stages.

Probes 2-6 will give an indication about the feed temperature changes and also

how the feed is moving in the conditioner based on temperature changes. These

probes should read temperatures range 80-85C.

The topside probe 4 is an important probe in detecting steam flow especially in

conditioners where the steam pipe is connected at the top. This probe will be at

the left side of the feed in tube. If the temperature is in the range, then the flow

is good, but if the temperature is low then the steam is entering the feed in tube,

and it needs to be adjusted. See below diagram.

Probe 7 gives the feed temperature leaving the conditioner. The temperature is

just like in the conditioner.

Probe 8 gives the pelleted feed temperature left the die (press). This temperature

is usually above all temperature probes readings, because of the pressure

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

extracted on the feed and also the flow of the steam. This temperature could

reach 92C, but it is for very short duration.

Selecting method for adequate probes

Selecting the right probe type and the adequate probe design is essential to

collect valid data. Placing the probes in the conditioner is another important

task. Probes should be in the place between the pedals of the rotating shaft. This

is very delegate work and should be done by professionals.

Missing one millimetre may destroy the prob. We should put in mind there is

high temperature, feed moving and pedals rotating in the conditioner. The

probes should withstand all of this. Probe should have the following

specifications.

Probe design

1. Stainless steel body with raged smooth finish for easy cleaning.
2. It should be fitted in a plastic or Teflon insulation plug to eliminate heat

transfers for conditioner body temperature.

3. Thermocouple or RTD probes could be used (preferably RTD).

4. The range of the probe could be 0-120 C, and for the steam up to 200C.

The plastic plug should have the following specifications.

1. Very hard plastic, but not to be damaged when mounted in the
conditioner.

2. High temperature resistance.
3. Easy to shape and work with. See figure 1 for more details.

Figure1. Probe specification design.

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

Figure2. Probes Placements and dimensions of the conditioner and coolers

Numbers 2-8 are temperature probes in conditioner and 9-12 are temperature

probes in the cooler.

S
6

2720

Top View

8001150760

570

1000

3220

920

680

2620

600

180

370

640

2150
1600

1200
600

Top View

1060

240

850

Press

Feed Out

Pro bes Placeme nts
Condi rioner

Coo ler

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

Figure 3. Tower cooler with temperature probes places.

Outside Temperature

Feed Temperature

Air in

1
2

Probes Placem ent in the c ooler

Tow er Cooler w ith temperature probes in

P E L L ET M IL L

C OOL E R

Overflow sensor

Level sensor

Feed in

FEED

AIR INAIR IN

WARM AIR

FEED OUT

W a rm A Ir o u t

Outside normal Pressure

Vacuumed

Overflow sensor

Level sensor

Air in

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

Figure 4. Counter flow coolers showing air flow from bottom to top.

Figure 5. Placement of the probes in the conditioner.

Rules for probes temperature understanding

Understanding the information from the data loggers; first we need to set the

standards or rules for temperature goals inside and outside the conditioner. After

that, we can monitor the temperature levels to achieve the bacterial control

(Salmonella) or quality control (Williman, 2009). In general there are three

groups or sets of temperatures we are looking for.

1. First is the low temperature group, which is the feed (mixed ingredients)
temperature before the conditioner (in the mixer or in the feed in tube).

The temperature range is 20-25 C. It depends on storage and outside

temperature as well.

2. Second is the high temperature group, which is feed temperature in the

conditioner. The temperature range is 80-85 C. The die temperature

could reach 92C if above temperature is maintained (Ryszard Kuling,

2008).

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

3. Third is the warm to cold temperature group, which is the feed (pelleted)

temperature in the cooler. The temperature range is 20-75C. See

figure 6.

The temperature categories and levels in the conditioner

The next step is to monitor and control the feed temperature in these ranges

and analyze the results. Figures 7, 8, 9.

Figure 6. Standard feed temperature in the conditioner.

1. If the temperature of group 1 is higher than 30ºC.
This means that the steam is running to the feed mixer or to the feed

tube. The temperature may reach 50ºC. This happens a lot especially

with conditioners having their steam pipe connected from the topside after

the feed in tube, and also with other steam tube connection if the steam

flows is restricted in the conditioner (more stem than the conditioner can

handle). This situation could emerge when

The die is chocked-full with feed,

Bad start up or interrupted runs.

Then the conditioner temperature will drop below the standard range.

2. If the temperature of group 2 is lower than the range. This means
Some of the steam is running to the feed in tube.

Steam temperature is not enough to keep the conditioner temperature

in the range.

Steam is not mixing with feed ingredients properly; steam pressure is

low.

Probes may be faulty.

S t a n d a r d f e e d t e m p e r a t u r e

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 0 0

M i x e r t e m p . c o n d 1 c o n d 2 c o n d 3 c o n d 3 c o n d 4 c o n d 5 c o n d 6 d i e c o o l e r 1 c o o l e r 2 c o o l e r 3

L o c a t i o n

T
e

m
p

.
C

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

3. If the temperature of group 2 is higher than the range. This means.
The amount of steam is high.

Probes are exposed to direct steam flow.

4. If the temperature of group 3 is above the standard range. This means
Over flow or temperature sensors are not working properly.

The vacuum in the cooler is not set properly.

Flow of feed is very high (feed is not losing heat or not cooling).

Exhaust duct is not clean (feed particles build up on the sides).

RESULTS AND DISCUSSION

There are two things to look at in the run. First is the startup temperature

reaches the desired temperature. Second is the run or batch temperature. See

Figure 7. It takes the feed about two minutes to reach the 80 ºC planned

temperature. During that time 150-200 Kg (depend on conditioner capacity) of

feed passes through the conditioner without reaching the desired temperature of

80-85 ºC. This feed could be recycled so no feed will be allowed to go to the

storage bins without reaching the planned or targeted temperature. Steadiness of

the run has a great influence on the feed temperature in the conditioner. The

more stops (On and off) in the run the more unstable temperature in the

conditioner, and more feed going to the bins without reaching the planned

temperature. This situation could be bad if salmonella was present in the feed or

feed ingredients. This also means salmonella positive feed is been used to grow

birds. The birds will be infected with salmonella whatever the bio-security is.

Vaccination may help in situation like this.

The batch run temperature is the most important factor affecting feed

temperature. Figure 7 is showing the ideal run and the correct temperature in the

conditioner. Looking at the graph from top, the steam temperature is stable and

around 130ºC. This temperature could be optimized to reduce energy cost

without affecting the pelleting process. To optimize temperature is to keep the

temperature of the conditioner at its desired temperature and in the same time

minimizing the heat loss from the conditioner to the room, where environmental

temperature is usually lower. Insulating the conditioner by proper insulation will

reduce or prevent heat loss, which keeps the conditioner temperature stable and

that will reduce extra heat to keep the conditioner at its required temperature.

Press (die) temperature is also stable and it is between 90-93 ºC. The Inside

conditioner temperature (all probes) is in the same safe range of 82-83 ºC.

The retention time in the cooler has also an important role in keeping the

temperature longer. The top part of the cooler holds the feed temperature at 70-

75 ºC for about 5 minutes. This time allows the temperature to penetrate to the

core of the feed pellet. The temperatures of the cooler are also in the safe range.

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

Press (die) temperature is also stable and it is between 90-93 ºC. The Inside

conditioner temperature (all probes) is in the same safe range of 82-83 ºC.

The retention time in the cooler has also an important role in keeping the

temperature longer. The top part of the cooler holds the feed temperature at 70-

75 ºC for about 5 minutes. This time allows the temperature to penetrate to the

core of the feed pellet. The temperatures of the cooler are also in the safe range.

The top cooler temperature (probe 9) is around 70ºC, the more we drop to the

end of the cooler the more the temperature will drop, until it reaches 21.8ºC

(feed temperature leaving to the storage bins).

Also we can recognize that the air temperature could raise 3-4 º C inside the feed

mill that is from the outside temperature (outside temperature 14.9 º C, air

temperature entering the cooler is 18.9 º C). With air temperature rising relative

humidity will decline (dryer air). This will dry the feed faster and losses

moisture as well.

Tracing the feed in temperature (ingredients) one can say, that some of the steam

is entering to the feed-in tube (feed coming from the top, and the steam from

bottom) and raising the feed-in temperature which supposed to be around 25 ºC.

The incoming feed temperature is between 46-50 ºC. Steam going backward

may cause problems in pipes and could cause condensation or crust formation

on the sides. Losing steam to the incoming feed tube means there is not enough

steam in the conditioner to reach the required temperature, and also means there

is a problem in the system must solved and find out why the steam going back

instead going in to conditioner. Figure 8 shows the temperature changes when

the batch was controlled for feed mass flow.

One of the serious problems in cleaning conditioners is the crust formation

inside the conditioner figure 8. This problem is caused by the water

condensation on the body of the conditioner especially in cold weather, when

there is not enough time to preheat the conditioner before producing feed.

The crust will trap small particles from feed and form a thick paste. This paste is

not just trapping minerals and vitamins it may also be a good place for toxins

and bacteria growth as well.

The objectives of the project have been met and pelleted temperature was

according to authority guidelines in New Zealand, figure 9.

Recommendations

1- To increase feed temperature at start-ups a retention plate may be placed in
the conditioner or fully computerised system could be installed to monitor

and control the start-up temperature in the conditioner at stops and start

periods.

AL-Chalabi Diyala Agricultural Sciences Journal, 7 ( 2 ) 44 – 58 ,2015

2- The temperature difference between outside and conditioner temperature is
large, and to reduce that is to insulate the conditioner by proper and practical

insulation to prevent crust formation and reduce heat loss.

References

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feedmills. Economic Evaluation of Defra Policy on Food-Borne

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phytase supplemented broiler feed on tibia mineralization, calcium and

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Williman J., E. Lim, R. Pirie, P. Cressey and R. Luke. 2009. Annual report

concerning foodborne disease in New Zealand 2008. ESRClinet Report

FW09062. Christchurch: ESR.

. لحبيبيا تقيين نظام هراقبت لدرجاث الحرارة في هكيف العلف وأنشاء

*ألجلبي هحود احود ضياء

drdhia@coagri.uobaghdad.edu.iq -جايعح تغذاد - كهيح انضساعح –قسى انًكائٍ ٔ انًعذاخ انضساعيح -يساعذ أسرار*

الوستخلص

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تفيٍ دَفكا اٌ دسجح حشاسج انعه انفذاخم نًكيف انعهف ان ثيثفي وº 8=-<>انى ثينًكي انعه ان ثي

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و º 8:صُذٔق انرثشيذ انعهفي كاَد

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