PNS 251:2021 - 252:2021 Flashcards
PNS/BAFS PAES 251:2021
Corn mill – Specifications
combination of corn grits other than corn grits nos. 10 to 18 (e.g. corn grits no. 20,
corn grits no. 24) floured corn and bran
by-product
grits with particle size from 0.708 mm to 0.841 mm which passed through US
Sieve No. 20 but are retained in US Sieve No. 25
corn grits no. 20
grits with particle size of 0.707 mm and smaller which passed through US
Sieve No. 25
corn grits no. 24
fine powder by-product of corn milling process
floured corn
fines
embryo of the kernel removed during the degermination process
germ
outer covering of the corn kernel removed during the milling process
pericarp
hull
attachment of the kernel to the cob; the entryway of nutrients, water, etc. to
the kernel
tip cap
combination of germ, tip cap, pericarp, and corn grits
bran
whole grain of shelled corn
corn kernel
milled corn grains where the outer covering (pericarp), germ (embryo), and tip cap
have been removed leaving only the endosperm that passed through different sieve
sizes
corn grits
machine that removes the pericarp, crushes the kernel, polishes the grits, and sorts
the grits into different sizes
corn mill
used to remove the germ, tip cap, and pericarp from the corn kernel
degermer
ratio of the weight of degermed corn kernels to the initial weight of the degermer
output sample, expressed in percent (%)
degermer efficiency
process of separating germ, pericarp, and tip cap from the endosperm and reducing
it into grits without soaking the corn kernels before milling
dry milling
part of the corn mill used to grind the degermed corn kernels into corn grits
grinding assembly
part of the corn mill permitting smaller particles to fall through the openings by
means of oscillating or rotating screen, wire mesh, or perforated metal sheet
grit size separation assembly
sifter
refers to Corn Grit Nos. 10, 12, 14, 16, and 18
main product
grits with particle size from 1.69mm to 2.00mm which passed through US
Sieve No. 10 but are retained in US Sieve No. 12
corn grits no. 10
grits with particle size from 1.42mm to 1.68mm which passed through US
Sieve No. 12 but are retained in US Sieve No. 14
corn grits no. 12
grits with particle size from 1.20mm to 1.41mm which passed through US
Sieve No. 14 but are retained in US Sieve No. 16
corn grits no. 14
grits with particle size from 1.01mm to 1.19mm which passed through US
Sieve No. 16 but are retained in US Sieve No. 18
corn grits no. 16
grits with particle size from 0.842mm to 1.00mm which passed through US
Sieve No. 18 but are retained in US Sieve No. 20
corn grits no. 18
ratio of the total weight of main products to the total weight of corn kernel input,
expressed in percent (%)
main product recovery
quantity of corn kernels that the corn mill can process to produce corn grits of desired
size per unit of time, expressed in kilograms per hour (kg/h)
milling capacity
Classification
A. Grinding assembly
1. Steel huller
2. Rotary blade/hammer mill-type
3. Steel roller
4. Attrition-type
B. Grit size separation assembly
1. Oscillating
2. Rotary
A grinder consists of a fluted steel shaft operating inside a perforated steel screen, which also carries a projecting strip of steel whose distance from the shaft can be varied.
Steel huller
A grinder consists of rotating metal blades that reduce the size of degermed corn
kernels as a result of impact.
Rotary blade/hammer mill-type
Degermed corn kernels are ground using pair/s of rollers made of steel that rotate in
different directions.
Steel roller
A grinder that uses a pair of flat disks with series of grooves on the disk face. One disk
rotates while the other disk remains stationary.
Attrition-type
Corn grits are sorted into different sizes by passing through sieves of different mesh
sizes by reciprocating motion.
Oscillating
Corn grits are sorted into different sizes by passing through rotating sieves of different
mesh sizes.
Rotary
Fabrication Requirements
???, or any appropriate materials should be used in the manufacture of the different components of corn mill. Materials that are directly in contact with the product shall be ???.
- Steel bars, metal sheet or plate
- food grade
Performance Requirements
Main Product Recovery, minimum - 55
Losses, maximum - 5
Degermer Efficiency, minimum - 80
The maximum allowable noise level shall be
100 dB(A)
Warranty shall be provided for parts and services except for normal wear and tear of expendable or consumable maintenance parts for at least ??? upon the
acceptance of procuring entity of the corn mill. General requirements of the warranty shall conform to PNS/BAFS/PAES 192:2016 (Agricultural machinery – Guidelines on after-sales service).
one year
There shall be no ??? on the welded area.
crack
There shall be ??? between adjacent layers of weld metal and base metal.
fusion
The base of the corn mill shall be ??? without any noticeable
cracks and weak joints.
rigid and durable
The rotating components of the corn mill should be ??? and shall have safety guards.
statically and dynamically balanced
Parts of the corn mill that are exposed to the operator shall be free from sharp edges and rough surfaces. Warning notices shall be provided in accordance with
??? (Agricultural machinery – Technical means for ensuring safety –
General).
PAES 101:2000
PNS/BAFS PAES 252:2021
Corn mill – Methods of Test
cleaner that uses air to separate lower density material from the corn kernels/corn grits
such as floured corn, bran, and other foreign matters
aspirator
blower
ratio of the weight (kg) of the corn kernels to its volume, expressed in kilogram per
cubic meter (kg/m3
)
bulk density
milled corn grains where the outer covering (pericarp), germ (embryo), and tip cap
have been removed leaving only the endosperm that passed through different sieve
sizes
corn grits
whole grain of shelled corn
corn kernel
machine that removes the pericarp, crushes the kernel, polishes the grits, and sorts
the grits into different sizes
corn mill
cracked corn kernels where the germ, tip cap, and pericarp have been removed
degermed corn kernels
ratio of the weight of degermed corn kernels to the initial weight of the degermer output
sample, expressed in percent (%)
degermer efficiency
any matter which is not corn kernels/corn grits such as corn cobs, sand, gravel, dirt,
pebbles, stones, lumps of earth, clay, mud, weeds, and other crop seeds
foreign matter
impurity
part of the corn mill used to grind the degermed corn kernels into corn grits
grinding assembly
part of the corn mill permitting smaller particles to fall through the openings by means
of oscillating or rotating screen, wire mesh, or perforated metal sheet
grit size separation assembly
sifter
weight of shelled corn kernels loaded to the hopper/intake pit per unit time, expressed
in kilogram per hour (kg/h)
input capacity
equipment with shaking motion used to separate particles by passing them through a
series of standard sieves
laboratory sieve shaker
quantity of corn kernels that the corn mill can process to produce corn grits of desired
size per unit of time, expressed in kilograms per hour (kg/h)
milling capacity
amount of moisture in the corn kernels expressed as percent (%) of the total weight
of the sample
moisture content (wet basis)
total weight of the main products collected per unit time, expressed in kilograms per
hour (kg/h)
output capacity
distance between the vertical planes perpendicular to the median plane of the
machine, each plane touching the front and rear extremities of the machine
overall length
distance between the vertical planes parallel to the median plane of the corn mill, each
plane touching the outermost point of the corn mill on its left and right sides
overall width
auxiliary device of the corn mill that removes foreign matter
pre-cleaner
electric motor or engine used to run the corn mill
prime mover
ratio of the weight of clean corn kernels, to the total weight of unclean corn kernels,
expressed in percent (%)
purity
total energy or fuel consumed over total weight of corn kernel input, expressed in
kilowatt-hour per kilogram (kW-h/kg) or liters per kilogram (L/kg)
specific energy consumption
manufacturer, direct importer, technology generator or any legitimate distributor,
dealer, or end-user of the machine that officially applied for a machine test
test applicant
Test materials
The corn kernels to be used shall be from ??? with at most ??? and at least ???. The amount of test material to be supplied shall be sufficient for at least ???. The excess amount shall be used for laboratory tests and running-in prior to the actual conduct of test trials. The test samples to be used for the running-in and in each test trial shall be prepared in such a way that they shall have identical characteristics in terms of ???. If the test
materials do not conform to the recommended quantity and characteristics, the test engineer shall not pursue the test.
- commonly or locally grown white corn flint variety
- 14% uniform moisture content (MC) (wet basis)
- 95% purity
- one hour of milling operation
- moisture content, purity, and variety
The corn mill shall have undergone a ??? before starting the test.
running-in period
Test Trial
A minimum of ???, with duration of at least ???, shall be adopted.
- three test trials
- 15 minutes per trial
Duration of test
The input time shall start at the feeding of the corn kernels to the intake hopper/intake
pit and ends when there is ???.
The operating time shall start at the ??? of the corn kernels to the intake
hopper/intake pit and ends after ??? of the main products at the main
outlet/s.
The output time shall start from the ??? of the corn grits at the main outlet/s
and shall end after the ??? of corn grits.
- no more corn kernel in the hopper/intake pit
- feeding
- the last discharge
- first discharge
- last discharge
The sound emitted by the machine, with and without load, shall be measured using a ??? at the location of the operator/s.
The noise level, expressed in decibel [dB (A)], shall be measured ??? away from the ear level of
the operator/s.
- sound level meter
- 50 mm
For each data to be taken, there shall be a minimum of ???.
Before taking data, it should be ensured that the feed rate, speed, and other functional
characteristics have stabilized. The time of recording shall be properly spaced during the whole duration of the test trial.
five observations
Using electric motor as prime mover
Use a ??? to measure the voltage, current, and the total electric power requirement of the corn mill. There shall be ??? with a minimum of ??? taken with and without load.
- power meter
- three sets of data
- five observations per set
Using engine as prime mover
To get the amount of fuel consumed, ??? shall be used. The tank shall be filled to full capacity or to a certain level before the test. After each test, the tank shall be filled with measured fuel to the same level before the test. When filling up the fuel tank, extra attention shall be paid to keep it horizontal and to ensure that empty space is not left inside.
- refill method
Speed of components
The speed of the rotating shafts of the major components of the corn mill with and
without load shall be taken using a ???.
tachometer
The percentage of corn grits other than corn grits sizes no. 10 to 18 from each
outlet shall be determined using a ???.
laboratory sieve shaker
Sampling procedures for the corn kernel input
The crop conditions such as ??? of corn kernel to be used in each test trial shall be taken using “representative samples”, each weighing at least ???. This is done by taking samples, each at
the ???. Samples representing the materials for each
test trial shall be placed in appropriate containers for laboratory analysis.
- purity, bulk density, kernel dimensions and moisture content
- three kg
- top, middle, and bottom of the pile
Sampling from different outlets
During each test trial, ??? samples each shall be collected from the outlets of the different components (degermer, grinder, sifter, aspirator etc.) of the corn mill to be analyzed in the laboratory. The minimum amount of sample to be taken shall be ??? for a particular analysis. The excess sample shall be used
for reference purposes or for an eventual second check in case of review.
- three
- twice
as much as what is needed
Purity determination
Take ??? samples from the “representative samples” of the input. Clean the
corn kernels to remove the impurities. The clean corn kernel shall be weighed and
recorded.
three 500 g
Moisture content
This shall be taken using a ???. ??? shall be taken for moisture content determination using a calibrated moisture meter.
Using oven method based on ISO 6540:1980, ??? is drawn from the bulk corn kernel sample. The ??? determined from the 100g samples shall be taken as the moisture content of the corn kernels.
- calibrated moisture meter or by oven method
- Five samples
- three samples of not less than 100 g each
- mean value
Measurement of Corn Kernel Input Dimensions
E.3.1 Randomly take at least ??? of corn kernels from the representative
samples collected from the test material.
E.3.2 For each sample, measure the ??? using a grain caliper. Record the measurement to the nearest ???.
- 10 pieces
- length, width, and thickness
- 0.01 mm
Determination of Bulk Density of Corn Kernel Input
Bulk density of kernel samples shall be measured using a ???. There shall be at least ??? trials conducted.
- calibrated bulk density tester/meter
- three
Analysis of output to determine the degermer efficiency
??? samples shall be taken from the degermer output samples. These
samples shall be analyzed to determine the percent degermed, undegermed and impurities.
Three 100g
Analysis of product outlet
In each test trial, take ??? samples from each main product outlet. Using laboratory sieve shaker with standard sieves, determine the percent of corn grit sizes present in the output from different main product outlets.
three 100g
