Why choose Hongdefa for maize milling machines

SHIJIAZHUANG HONGDEFA MACHINERY CO.,LTD
ADD: SHIJIAZHUANG, HEBEI, CHINA
MOBILE:0086-15533926058
EMAIL: vanisa@vip.126.com
WEB:www.wheatmaizemilling.com

S H I J I A Z H U A N G H O N G D E FA M A C H I N E R Y C O . , LT D
Address: No.388 NORTH JIANHUA STREET SHIJIAZHUANG, HEBEI, CHINA.
Mobile:0086-15533926058 Tel: 0086-311-85528086 Email: vanisa@vip.126.com
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 Modernized professional factory with over 35-year experience
The head office of Shijiazhuang Hongdefa Machinery Co.,Ltd is located in Wumashan industarial area,
Zanhuang County, Shijiazhuang City, 4hours driving From Beijing.
Hongdefa has approximately 120 workers, a manufacturing factory 50000 square meters, and 5000 square
meters of production workshop, 6000 square meters warehouses, 1000 square meters of office space.

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 Advanced Processing Equipment:
China and Australia Wheat Flour Mill Technology
China and South Africa Maize Mill Technology
Shijiazhuang Hongdefa Machinery Co.,Ltd is a professional manufacturer of wheat flour mill and
maize mill,provide high quality machine from 500kg/h to 50ton/h with different design according to
our client needs,with European technology,South Africa maize process,China wheat process, roll
out unique and innovative wheat flour mill and maize mill plant.

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 Certificate
All our machinery are high quality and have passed the certification of ISO, CE, BV, SGS and COC.

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 Patent for Degerminator
 Lifelong oversea services
Since 2007, we opened the branch office in Lusaka of Zambia,where has a big storage room, easy
access to some machines and spare parts for Zambia customers. The manager Mr Dongpu Guo lives
in Lusaka all the year,and if any needs, he can go to visit customers in Zambia and see the site of
land or workshop building and give some good advise to customers.We have installed many
different capacity of maize milling plant in Lusaka, Kitwe, Mongu, Mansa, Chipata, Solwezi,
Kabwe etc. Supplied machines to APL milling,N.R. Investment Ltd, Jimbara milling Ltd etc.
We also put an office in Addis ababa of Ethiopia, Kampala of Uganda, Sydney of Australia,and we
have agent from Brazil and Kenya.
 Pre-sales Consultation
We can design the processing technology according to your requirements.
 Equipment Installation
Our professional technicians offer the guidance of installation, commissioning the machines,build
up the workshop building and silos,and we can also help to reform the old workshop building as per
customers’ condition.

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 Training
Our professional technicians provides training workers of customers’ factory,which is helpful to
guarantee the normal operation of the equipment and reduce its downtime. In this way, the quality
of finished products will be guaranteed.
 Fixing and Maintenance
Our professional technical team can help solve any problem that occurs in customer’s flour
production efficiently. We can do regular examinations to the equipment and offer you guidance on
the equipment operation if you need. Our staff in Lusaka Office can go to see your site and
machines directly and give some advise face to face.
 Spare Parts Supply
Normally we will send you some wearing parts available for one-year operation of the equipment in
our first order. When you are in need of new spare parts in the future, we can send directly from
Lusaka/Zambia Office timely where have put a big storage room and delivery door to door.
 Experienced technician and sales team
Mr. Huang
More than 30years
experience,have
stayed in South Africa
for 3 years studying
the African maize &
technology.
Mr. Chen
More than 40years
milling experience.
Top Rand designer
of the milling
machine in China.
Professor of Henan
University.
Mr. Ma
More than 30 years
experience. Have
guide designing and
manufacturing many
sets of milling
machines for
different markets.
Mrs.Rita
Sales manager
More than 13years
experience for
selling, have studied
maize mill technical
in South Africa.

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 Hongdefa projects
COUNTRY PROJECT PHOTOS
ZAMBIA
APG MILLING (3000T SILO AND
MACHINES)

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150-170T/D N.R. INVESTMENT. LTD IN
KITWE
100-130T/D ASCENSIO INVESTMENT LTD IN
SOLWEZI
ZAMBIA
150-170T/D MONGU MILLING PLANT IN
MBALA
 150-170T/D CMF MILLING LTD
(SARHAN SALIM OWNER OF COPPERHILL MALL IN KITWE)
 100-130T/D GLANCE MILLING LTD IN KABWE
 100-130T/D CHILILABOMBWA MILLING PLANT IN CHILILABOMBWA
(NEAR TOTAL FILLING STATION)
 100-130T/D JIMBRARA MILLING LTD IN MANSA
 240T/D CHAOMA MILLING LTD

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50T/24H MAIZE MILL MACHINE 2SETS
STORE SILO
WAREHOUSE
500T SILO*2SET
40T/24H MAIZE MILL MACHINE
160T/24H WAREHOUSE 4 FLOOR
ZAMBIA 50T/24H MAIZE MILL MACHINE

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35T/24H MAIZE MILLING MACHINE
ZAMBIA 35T/24H MAIZE MILL MACHINE
SOUTH
AFRICA
500T/24H MAIZE MILL MACHINE (3SETS)

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 100T/24H MAIZE MILL MACHINE
KENYA 150T/24H MAIZE MILL MACHINE
 KABANSORA MILLERS LTD/NAIROBI
 50T/24H MAIZE MILL MACHINE WITH SILO AND WAREHOUSE
 20T/24H MAIZE MILL MACHINE ETC

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TANZANIA 50T/24H MAIZE MILL MACHINE
 10T/24H MAIZE MILL MACHINE ETC
ANGOLA 250T/24H MAIZE MILLING PLANT
BENIN 120T/24H MAIZE MILL MACHINE
INDIA 70T/24H MAIZE MILLING PLANT
ZIMBABWE  90T/24H MAIZE MILLING PLANT
 150T/24H FLOUR MILL MACHINE
NAMIBIA  60T/24H MAIZE MILLING PLANT
 10T/24H MAIZE MILLING PLANT
RWANDA 30T/24H MAIZE MILLING PLANT
UGANDA  50T/24H MAIZE MILLING PLANT
 MUKWANO GROUP COMPANINES

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GHANA 36T/24H MAIZE MILLING PLANT
EGYPT 250T/24H FLOUR MILLING PLANT
60T/24H FLOUR MILLING PLANT
ALGERIA 60T/24H FLOUR MILLING PLANT
BRAZIL 250T/24H FLOUR MILLING PLANT

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60T/24H FLOUR MILLING PLANT
ETHIOPIA
(MORE
CLIENT )
 500T/24H FLOUR MILL
Afghanistan 300T/24H FLOUR MILL
SIX FLOOR BUILDING MAIZE MILL FOR 500TONS/24H

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FOUR FLOOR BUILDING FOR MAIZE MILL LINE

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500TONS/24H MAIZE MILL LINE/SOUTH AFRICA

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150TONS/24H MAIZE MILL LINE/KENYA

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 Client photos
Brazil India

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The core technologies of our group are in the filed of wheat flour mill and maize mill
process engineering, with European technology, South Africa maize process, China
wheat process, roll out unique and innovative wheat flour and maize meal processing
line . It has the following features:
1.Roller Mills
1)The partitioned paneling and swing-out feed module guarantee ideal
access to the feeding and grinding rolls. This makes residue-free
cleaning possible.
2) a pulse generator automatically adjust the feed material at the entrance door
3) bearing SKF
4) temperature monitor (option)
2.Roller: Two different alloys with a mixing ratio allow the perfect balance
to be achieved between hardness and roughness.
3.Plansifter
1) Material: High-strength alloy steel
2)up and down sifter circles with steel plate overall by bending
3)Transmission system using spring force component institutions
4)Sieve frames of wood coated with synthetic resin,without backwire
5)All the inside walls as well as the doors are provided with high-grade insulation
6)Vertical and horizontal clamping system
4.Dampener: Stainless steel.

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5.Bucket elevator and conveyor with reducer
6.PIPE:stainless steel in milling section
7.Electronic parts: Siemens/Schneider

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8. Plant Control System : PLC Controlling system.
9.Motor:Siemens
10.Reducer:flender/sumitomo /sew
11.Fortified dosser:for vitamins and minerals
12.Semi-automatic packaging machine: Detect weight,measure number of bags and
fill automatically,customized as per client needs.

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Introduction of each machine
Bucket elevator: Bucket elevator is the vertical machine for lifting the raw material, and the
worm conveyor is the horizontal machine for carrying the material. As have too much machines,
we designed use vertical technical flow and horizontal flow in the factory to save area and hight of
the building.
High-performance belt:
Reinforcing material
made of synthetic
gumming canvas,warp is
low shrinkage polyester
filament , nylon filament
weft ; between the belt and the head wheel
add one layer durable base fabric; very good
for grain and good processing
The body bend with
one plate,no welding ，
long life.
High-speed vibratory sieve:
Vibrating sieve is a sifting machine with high speed.
The principle is when the sieve body are droved by two sides vibrating motors, maize flow into the
first sieve surface through feeding entrance, large impurity on the upper sieve is discharged to the
hopper. Another material come into the second sieve surface for continual sift. On this surface, the
maize and small impurity are separated each other. Finally lighter impurity is discharged by the
suction pipes. This machine has much speciality such as high
capacity, without jaming and so on. The function is the sieve
remove all impurities from maize to reduce dust and impurity
to pollute workshop as much as it can. And ensure rear
working line with good running. Meanwhile to avoid jaming
into the slip of screw conveyor and exit of damper bin.
Main Area No welding Quality sheet
Vibration smooth uniform feeding
Special Drawer design,easily to maintain
Galvanized Bolt Tight

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 Magnetic separator: Avoiding the metal material running a high speed into the machine to make
a spark under beating and friction situation.
Gravity classifier destoner: According to different gravity between maize and same size stones,
and air dynamics, adopt destone and sieve performance and movement parameter, and air current
speed, the destoner to classificate the raw material. The maize and stones moving on the sieve with
different direction, made the stones are separated from wheat.
■ Higher efficiency destoner,shutter sieve structure
■ Easy operation, compact structure.
■ For different materials,destoner sieve can adjust between 10-14 degree
■ External fan, whole machine sealing , no dust outside, to achieve the desired environmental
requirements. Reciprocating swing,splices using rubber bearings, vibration low, low noise.
■ Adopt self-aligning bearing with locking device, so that the mechanical character more stable

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Damper: Specially for maize
Computer control moisture
Bi-Direction screw,prevent free water
Intensive intermixing
Stainless steel screw leaf and outside
No Leaking
Degerminator: Degerminator is designed to scrub the maize skin from the maize kernel,and
to dislodge the maize germ from its cavity,with the minimum reduction in size of the broke
fragments.

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Roller Mill: The mill the most important one machine of whole processing line, is mainly for
grinding. To break maize and bran’s structure, and spearate the maize husk and the embryo from
endosperm by grinding.
The partitioned paneling and swing-out
feed module guarantee ideal access to
the feeding and grinding rolls. This makes
residue-free
A pulse generator automatically adjust
the feed material at the entrance door
Bearing SKF
Sensor Omron

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Plansifter can classify the material that from break, reduction and scratch systems and sifting the
flour.
Material: High-strength alloy steel
Up and down sifter circles with steel plate overall by bending
Transmission system using spring force component institutions
Sieve frames of wood coated with synthetic resin，shape no change
All the inside walls as well as the doors are provided with high-grade insulation
Vertical and horizontal clamping system

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Gravity Table: which use the gravity is select the granual which is same size with the grits,to
improve final products extraction
This machine is the use of germ and corn granules specific
gravity and different suspension velocity air stream by means
of physical action up through the corn grits and corn germ
gap prompted particle sizing, as directed in the inclination to
mention the role of the embryo reciprocating sieve, corn
granules to the discharge end of the movement. Floating on
top of the germ under its own weight, to the embryo
population movements, thereby germ separated from corn
residue
 Turbo sifter is a perfect sifting equipment,combined vibrating shifting and centrifugal
sifting,the screen hole not block,and more suitable for sticky material,widely using sifting the
bran and flour

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 PLC Control system

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 Scale:Online scale and auto-packing scale
1.Online auto cumulative weight;
2.High-precision on-line flow control;
3.Frequency (batch) weight control;
4.With MODBUS communication interface with computer networking, computer centralized
management control;
5.According to customer needs, can have the print function.
6.Feeding and support is stainless steel.

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 PIPE: All pipes in milling section where contact the material are stainless steel.
 AIR SYSTEM
Screw air compressor
Belt tensioning convenient, simple replacement of the belt structure, completely
eliminate mechanical resonance
According to acoustic principles, enclosures closed, eliminating noise

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1) MAIZE MILLING DESIGN INSTRUCTION
COMPOSITION OF MAIZE PRODUCTS
CLASS OF
MAIZE
PRODUCT
FAT CONTENT
BY MASS %
FIBRE
CONTENT BY
MASS %
FINENESS BY MASS
MIN MAX MIN MAX
1. Samp - 1.5 - 0.8
Not more than 5% shall be whole grain and not
more than 5% shall pass through a 2.36mm sieve.
2. Maize Rice - 1.5 - 0.8
At least 90% shall pass through a 4.0mm and not
more than 5% shall pass through a 1.18mm sieve.
3. Maize Grit - 1.5 - 0.8
At least 90% shall pass through a 1.4mm sieve and
less than 90% shall pass through a 300 micrometer
sieve.
4. Maize Flour -
Less
than 2.0
- 0.8
At least 90% shall pass through a 300 micrometer
sieve.
5. Super Maize
Meal
-
Less
than 2.0
- 0.8
less than 90% shall pass through a 300 micrometer
sieve.
6. Special
Maize Meal
2.0
Less
than 4.0
- 1.2 At least 90% shall pass through a 1.14mm sieve.
7. Sifted Maize
Meal
3.0
Less
than 4.0
- 1.2 At least 90% shall pass through a 1.14mm sieve.
8. Unsifted
Maize Meal
3.5
Less
than 4.5
More
than
1.2
2.5 At least 90% shall pass through a 1.14mm sieve.

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9. No.1 Straight
Run Maize
Meal
3.7 - 1.8 2.5 At least 90% shall pass through a 2.36mm sieve.
10.No.2
Straight Run
Maize Meal
3.7 -
More
than
2.5
6.5 At least 90% shall pass through a 2.36 mm sieve.
11. Unsifted
Crushed Maize
3.2 1 1 2.5
Not more than 5% shall be whole grain,and not
more than 40% shall pass through a 2.36mm sieve
12. Sifted
Crushed Maize
1.5 - - 2.0
Not more than 5% shall be whole grain,and not
more than 5% shall pass through a 1.18mm sieve
13. Fine
Crushed Maize
1.5 - - 2.0
At least 90% shall pass through a 2.36mm sieve
and not more than 10% shall pass through a 1.0
micrometer sieve.
14. Maize
Germ Meal
10.0 - - - -
15.Fine Maize
Bran
-
Less
than
10.0
More
than
6.5
17.0
at least 50% shall pass through a 1.4 micrometer
sieve.
16. Coarse
Maize Bran
-
Less
than
10.0
More
than
6.5
17.0 -
17. Industrial
Grade Maize
Product
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Though not strictly applicabe to products many of the above fat and fibre contents are still recommend in most
company based quality matrix.
OUTLINE OF THE MAIZE MILLING PROCESS
1. PREPARATION OF THE MAIZE FOR THE MILLING PROCESS
Before the milling process proper can commence the maize must be suitably prepared. During this operation all
impurities and foreign matter are removed, and finally the maize is conditioned by allowing a controlled quantity
of water to penetrate the bran before the grain is ready for milling.
2. THE MILLING PROCESS
The process of manufacturing the products involves three fundamental sub-processes. The first of these,
physically detaches the three components of the maize kernel from each other. with as little dilution or mixing as

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possible.second, sorts and classifies the detached particles into specific groups and the last, sizes and reduces the
particles to the required granularity. The three components are then recombined as necessary depending on the
type of finished product
Required The aim of the process then, is to detach the bran and germ from the maize kernels with a minimum
disintegration of either the endosperm or the bran/germ casing. The pure endosperm is then gradually reduced in
size to form products of different granularity, ranging from the relatively large pieces of camp to the very Fine
maize flour. Some of the bran and germ are also ground down in the process and a certain amount combined with
the ground endosperm to meet the specifications of the coarser meals such as sifted and unsifted maize meal.
2.1 Detaching the bran and germ from the endosperm
This part of the process is carried out 6y treating the conditioned maize on either a degerminator or a roller mill.
2.1.1 The degerming process
The action of the degerminator is designed to 'scrub' the bran skin from the maize kernel and to dislodge the germ
from its cavity, with the minimum reduction in size of the broken fragments.in the machine the maize is subjected
to a rubbing, tumbling action by a revolving cone with a very coarse surface which peels the bran from the
endosperm and frees the germ. At the same time the machine effects a rough Separation of the broken endospem
pieces from the fragments of bran and Germ by means of a perforated screen. Because of varying maize
characteristics,And imperfections in machine design, a certain amount of breakage and Imperfect separation is
unavoidable and much be rectified later in the process.
2.1.2The roller mill process
For the purpose of detaching the bran from the endosperm, very coarsely fluted rolls are used, The shearing
action provided by the flute spiral and roller speed Differential breaks open the whole maize kernels and detaches
much of the endosperm from the bran and germ.
However, this does not provide as much clean endosperm as the degerminator and a good deal of work remains to
he done later in the process, but the roller mill does have an advantage in that the action does not pulverise the
germ and bran to the same extent as the degerminator.
2.2 Sorting and classifying the broken particles
This is the second part of the milling process and involves the use of several different types of sieving machines as
well as aspirators.
2.2.1 The drum type sifter or Le Coq sifter
Because of its sturdy construction and high capacity, this type of sieving machine is often used to separate the
germ meal fraction from the broken endosperm particles produced by the degerminators. The separation effected
is only a rough one but it greatly facilitates the later sieving operations on the plansifters.
2.2.2 Plansifter
The modern plansifter has been developed into a highly efficient machine capable of sorting a single feed into six
or seen different ranges of particle size. This is done by using several different mesh aperture sizes which effect
the separations mainly as a result of difference in particle size as wail as variance in density and shape. The action

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of the plansifter causes endosperm particles, with
their inherently higher density and comparatively spherical shape, to work their way down to the lower layers,
while the germ and bran particles remain in the upper layers. The size of the particle In relation to that of the
aperture of the sieve, then ultimately determines whether the particle will pass through the aperture or not. Using
these principles the plansifter classifies the broken particles of maize so that they may he processed more
efficiently on the Machinery which follows.
2.2.3 The Concentrator or gravity table
This machine continues the classification of the particles by utilising a combination of air currents and an
oscillating deck to sort out particles according to differences in density. Since endosperm is appreciably denser
than germ, which in turn is denser than bran, a single stream, consisting of a mixture of these particles, can be
classified into as many as four groups of varying purity Prom pure endosperm at the one extreme to pure bran at
the other, with varying combinations of Composite particles in between.
2.2.4 The Aspirator
Throughout the milling process one of the Chief aims is to Isolate bran and germ Particles from clean endosperm
in order to prevent contamination of the finished products.
The aspirator is particularly useful in this regard as it sorts out the particles by Using their disparity in air
resistance. The shape of a particle plays a significant Part in determining its behaviour in an air current and since
bran (and, to a lesser extent, germ) in addition to having a lower density, tends to be flake-shape,it is ideal for
separation by aspiration.
2.3 Reducing the particle size and sifting out the products
Final reduction in size of the cleaned and graded maize particles is always carried out by roller mills. Finely fluted
rolls are used and the accuracy with which the Severity of the grind can be set makes the roller mill ideal for this
purpose. The plansifter is also ideally suited for the purpose of sizing the ground particles according to the
required granulation. Particle sizes in the finished products range from 4000 microns in the case of maize rice
down to 300 microns for maize flour and all of these can be accommodated by the range of sieves available in the
modern plansifter.
2.4 Summary of the process
The entire milling process in constituted by combining the sub-processes referred to above into groups of series
and parallel operations. A simple example is shown in Diagram 1. Each group performs basically the same
operation, the only difference being that the particle size gradually diminishes as the process proceeds step by step
from raw material to finished product.
In general terms the machinery flow sequence is: degerminators and roller mills- plansifters 一 aspirators 一
concentrators 一 rollermills. The reason for this sequence can be readily appreciated by considering the nature of
the particles before and after each treatment.
To begin with, a wide range of different sized particles is created during treatment by the degerminators and
roller mills. To facilitate separation and subsequent processing, the particles must first be classified into groups,
each having a narrow range of particle size. This is why the plansifters always follow the roller mills.

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Once the particles have been classified into size groups, advantage can be taken in differences in nature of the
particles which make up the kernel components. The bran,being significantly different from either germ or
endosperm in air resistance, is readily separated first by means of aspirators. With the bran removed, germ can be
separated from the endosperm on the concentrators or gravity tables, according to density differences.
Endosperm particles, now comparatively free from Both bran and germ and the unavoidable fragments cut up
during the roller mill process,can then be suitably sized on another roller mill In order to meet granularity
specifications.
3.THE DEGERMING PROCESS
3.1 The degerming process originated in America where it was developed as the quickest and easiest way to
remove the germ and outer bran covering from the maize kernel. In the USA, maize is seen as a valuable source of
vegetable oil and the farmers are encouraged to cultivate varieties of yellow maize with large germ components
and high oil content. In this milling process, the main objective is to recover as much of this valuable portion of
the maize kernel as possible, and so, in effect, the germ fraction is considered to be the prime product, while
the endosperm and bran are treated as the by-product and disposed of mainly as cattle feed. Some of the
endosperm is recovered in the form of samp or grits and used in the production of breakfast cereals or snack
foods。But of prime importance is the germ oil from which then, so many types of food are obtained. In the
American process,the emphasis is on the production of as much good quality germ as possible and the incidental
breaking up of the endosperm is considered to be of minor importance.
Perhaps because of this, the design of the degerminator is robust,with few refinements and its action in separating
the bran from the endosperm and dislodging the germ is extremely rough.
In our country on the other hand, the aim of the degerming process is to remove the bran from the maize kernel
and dislodge the germ from its cavity with the minimum damage to the endosperm, bran and germ. This facilitates
the sorting process which follows degerming and is designed to separate the endosperm, bran and germ from each
other and to minimise possible contamination of the clean endosperm fraction with the oil from the germ.
Further processing on the mill converts the endosperm into various finished products such as samp, grits or meal
which, in this case, are the prime products, while the combined germ and bran fraction, which remains a
valuable source of oil, constitute the by-product.
The type of degerming used in the South African milling process varies to some extent and may take the form of
1. a full degerming of the maize to produce clean samp (damp degerming);
2. a type of skinning procedure where only a partial removal of the germ and bran takes place;
3 or 'partial damp' degerming which differs considerably from the other two.
3.2. DAMP DEGERMING PROCESS FOR SAMP WITH HORIZITAL TYPE DEGERMERS
This is a 'damp' degerminating process which involves the use of steam or water to rise the moisture content of
the outer bran layers of the maize kernels before they enter the degerminator. A 'HORIZITAL type' degerminator
is used, based on concept, and the purpose is to produce a high proportion of large endosperm pieces or samp,
from which all the bran and germ has been removed, with a minimum amount of damage to any of the three
components.

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3.2.1 Condition of the maize
In order to achieve the best results, it is vitally important that the maize feeding the samp degerminator
should be in optimum condition. The type of maize will affect results and it is best to use a hard, dent type if a
good yield of samp is to be obtained. Soft local varieties are unsuitable as they break up too easily and produce
large quantities of fine endosperm particles which mix irretrievably withthe bran and germ fragments. This
problem was experienced in recent years by mills throughout the country when drought conditions forced the
millers to rely on soft, yellow maize imported from America and Argentina.
Most of the white dent varieties of maize produced under normal conditions in South Africa are suitable for
use in the samping process but, in addition to cultivar,
The following points should also be noted in selecting the maize:
1. The endosperm must be free of cracks or stress lines which are usually caused by negligent drying
techniques on the part of the producer;
2. the kernels must be whole and preferably as evenly sized as possible;
3. The maize must be clean and free from loose impurities; and
4. The natural moisture content should be low enough so that it is possible to add the required amount of
water in the conditioning process.
If the maize selected conforms as nearly as possible to the above requirements, it should be possible to deliver the
maize to the degerminators in the best possible condition for samping.
In order to produce the best results, the final condition of the maize should be such that:
1. The endosperm remains as hard as possible and has the maximum resistance to attrition;
2. the bran is as tough as possible. This includes the black tip cap which must be removed intact, with
the bran;
3. the germ is firm and pliable;
4. the adhesion between the bran and endosperm is at its lowest.
The methods used to achieve correct conditioning have been covered in Module 2but, in general, they involve
controlled moisture addition in the form of water or steam and carefully set lying times, in order to allow limited
penetration of the maize kernel. There is a divergence of opinion on moisture addition limits as well
as optimum penetration times but these will vary depending on local conditions and the type of maize used.
3.2.2 Other factors affecting degerminating
3. 2.2.1 The feed
The capability of a degerminator to deliver good samp is directly affected by the consistency of the feed rate.
The maize should enter the machine at the rate recommended by the manufacturer, which is generally between
two and four tons per hour, and should not be allowed to vary. The rate is normally controlled by volumetric

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feeders but these must be checked regularly as foreign material very often accumulates inside the compartments
and so volume flow is reduced over a period even though the setting has not altered.
When a degerminator is underfed, not only is the power being wasted but also the breakage will increase
because the particles remain inside the degerminator for longer than necessary. Conversely, if the machine
is over-fed, the maize will not be properly degermed and the quality of the samp will be poor.
Electronically controlled variable speed measurers are now being used in the modern maize mill, their function
is to reduce feed automatically in the event of an overload condition on the main motor caused by a build-up of
feed in the degerminator. The feed rate does not vary under normal conditions. The regular flow of maize to the
machine may also be disrupted by a build-up of metal fragments on the magnet which is usually installed in the
feed spout. Besides obstructing the feed, this also reduces the effectiveness of the magnetic protection and could
result in damage to the rotor or casing.
3.2.2.2 The rotor cone adjustment
The pertormance of the degerminator may be controlled to a certain extent by altering the severity of the
treatment while the machine is in operation.'The main adjustment is effected by a leer, which moves the position
of the rotor cone in relation to the stationary casing. The correct setting is determined in association with the
tension on the discharge gate and is a matter of establishing the correct balance between the side and end
clearances in order to avid under- or over degerminating. Once the optimum position has been determined,
farther adjustments should not be necessary exce the rotor or casing.
3.2.2.3 The discharge gate adjustment
Any adjustment to the tension on the discharge gate (or tailsgate) has an immediate effect on performance as
this virtually controls the duration, and hence, the severity of the treatment. The tension must provide just
sufficient resistance to the maize flowing through the degerminator to enable degerming to take place without
undue damage to the particles.
3.2.2.4 Condition of the degerminator parts
Worn working surfaces inside the degerminator are bound to result in sub-standard results and efficient
operation depends on a degular maintenanceprogramme.
a. Worn scroll sections at the feed end will retard the maize at this point and upset the flow of product
through the machine.
b. Worn nodules will not be able to detach the germ and bran and will produce a high proportion of finely
ground germ meal.
c. Worn perforations will upset the balance between throughs and overtails while holed screens will allow
undegermed particles to fall through.
3.2.2.5 Germ meal
The germ meal referred to here and elsewhere in the chapter consists of a mixture of finely ground germ, bran and
endosperm fragments created by the abrasive action of the degerminator. This fraction passes through the holes in
the perforated plates and constitutes the degerminatar 'throughs'. It contains most of the germ and bran and nearly
all of the water added in the conditionin gprocess. The moisture content must he reduced as quickly as possible by
means of artificial drying to prevent deterioration of the meal.

- 45 -
When a degerminator is operating efficiently, the fragmented endosperm content of the germ meal is reduced to a
minimum. This is indicated by a low percentage germ meal figure showing that most of the endosperm is
overtailing the degerminator in the of large pieces of samp. Too much tine endosperm in the germ meal is a sing of
inefficiency and may be the result of soft maize, poor conditioning, incorrect machine setting or worn working
surfaces.
3.2.3 Advantang of the damp degerming process
The principal advantage of the process is that it yields a high percentage of large. fully degermed samp from
which a variety of other grade prodcts such as maize rice and brewers grits can be produced. Supe maize meal and
other meals produced from the samp are also of excellent colour and quality.
Break and reduction roll systems
This chapter deals with the further treatment of the relatively pure endosperm pieces which were produced by the
degerming system as described in the previous item.This is the last part of the actual milling process where most
of the finished products are finally produced.
The function is to reduce the endosperm to intermediate size particles which are divided into several different
grades which facilitates more accurate grinding on the reduction rolls.In setting these rolls it should be borne in
mind that the aim is to size the particles for further processing and while a small amount of meal will inevitably be
produced, this is not the main objective.the severity of the grind at this stage should never be sufficient to produce
maize flour
4.Sifting system
5.Balance system
6.Packing Machine

Why choose Hongdefa for maize milling machines

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Why choose Hongdefa for maize milling machines