ICS 65.060.01  
 
Reference number  
DRS 269 -4: 2020  
© RSB2020  
  
 RWANDA 
STANDARD  DRS  
269-4 
 
2nd edition  
2020 -June  
 
Agroprocessing machine s — Test 
methods  —  
Part 4 :Heated air mechanical grain dryer  
   
DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB2020  
All rights reserved. Unless  otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce thi s document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov. rw 
ePortal: www.portal.rsb.gov.rw  DRS 269-4: 2020  
iii                ©RSB 2020  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ .....................  vi 
2 Normative references  ................................ ................................ ................................ ...........................  vi 
3 Terms and definitions  ................................ ................................ ................................ ..........................  vi 
4 General conditions for test and inspection  ................................ ................................ ......................  vii 
4.1 Machine on test  ................................ ................................ ................................ ................................ ... vii 
4.2 Role of manufacturer/dealer  ................................ ................................ ................................ ...............  vii 
4.3 Test site conditions  ................................ ................................ ................................ ............................  viii 
4.4 Measurement of dryer holding capacity  ................................ ................................ ..........................  viii 
4.5 Indication of damage  ................................ ................................ ................................ ..........................  viii 
4.6 Suspension of test  ................................ ................................ ................................ .............................  viii 
5 Test preparation  ................................ ................................ ................................ ................................ . viii 
5.1 Materials and equipment  ................................ ................................ ................................ ...................  viii 
5.1.1 Fuel ................................ ................................ ................................ ................................ ......................  viii 
5.1.2  Grain  ................................ ................................ ................................ ................................ ....................  viii 
5.1.3  Measuring instruments  ................................ ................................ ................................ ......................  viii 
5.2 Test set -up ................................ ................................ ................................ ................................ ............  ix 
5.3 Running -in and preliminary adjustments  ................................ ................................ ..........................  ix 
6 Procedures o f test  ................................ ................................ ................................ ................................  ix 
6.1 Verification of the specifications  ................................ ................................ ................................ ........  ix 
6.2 Performance test  ................................ ................................ ................................ ................................ ... x 
7 Ease of hand ling and safety feature  ................................ ................................ ................................ ... xi 
8 Laboratory analysis of dried samples  ................................ ................................ ................................  xi 
9 Formula  ................................ ................................ ................................ ................................ .............  xiixi 
10 Test report  ................................ ................................ ................................ ................................ ............  xii 
Annex  A (normative)  Specification of grain dryers (Continuous flow types)  ................................ ..........  xiii 
Annex  B (normative)  Specification for grain dryers (batch type) ................................ ..............................  xix 
Annex  C (normative)  Drying performance test ................................ ................................ ..........................  xxiii  
C.1 Crop conditions  ................................ ................................ ................................ ................................  xxiii  
C.2 Ambient conditions  ................................ ................................ ................................ ..........................  xxiii  
C.3 Dryer performance  ................................ ................................ ................................ ...........................  xxiii  
Annex  D (normative)  Laboratory analysis of samples  ................................ ................................ ..............  xxv 
D.1 Analysis of paddy samples  ................................ ................................ ................................ ..............  xxv 
D.2 Analysis of maize samples  ................................ ................................ ................................ ........  xxvixxv 
Annex  E (normative)  Formula to be used in computation of drying parameters  ................................ . xxvii  
 DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  iv 
 Foreword  
Rwanda Standard s are prepared by Technical Committees and approved by Rwanda Standards Board (RSB) 
Board of Directors in  accordance with the procedures of RSB,  in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards. Final Draft Rwanda Standards 
adopted by Technical committees are ratified by members of RSB Board of Directors for publication and 
gazettment as Rwanda Standards.  
RS 269 -4 was prepared by Technical Committee RSB/TC 047, Steel aluminium and related . 
This second  edition cancels and replaces the first  edition (RS  269-4:2015 ) which has been technically revised.  
DRS  269 consists of the following parts, under the general title Agroprocessing machinery — Test methods : 
 Part 1: Price thresher  
 Part 2: Power operated maize sheller  
Part 3: Rice mill  
 Part 4: Heated air mechanical grain dryer  
 Part 5: Maize mill  
Committee membership  
The following organizations were represented on the Technical Committee on Steel aluminium and related 
products (RSB/TC 047) in the preparation of this standard.  
University of Rwanda/college of science and technology  
University of Rwanda/College of agriculture animal science and veterinary medicine  
Kabizu business group  
Rwanda Polytechnic/IPRC Kigali  
Rwanda Polytechnic/IPRC Ngoma  
Rwanda Polytechnic/IPRC Musanze  DRS 269-4: 2020  
v                ©RSB 2020  - All rights reserved  
 RWANTECH Boilers  
Rwanda Inspectorate and competition au thority  
Rwanda Institute for Conservation Agriculture  
ACER Ltd  
 Rwanda Standards Board (RSB) – Secretariat  
 
  DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  vi 
  
Agroprocessing  machine s — Test methods — Part 4: Heated 
air mechanical grain dryer  
1 Scope  
This Draft  Rwanda Standard specifies the methods of sampling, testing and inspection for heated – air 
mechanical grain dryer . 
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references, only t he edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
DRS 2 68-4, Agroprocessing  machine s — Specification — Part 4: Heated air mechanical grain dryer  
RS 241, Agrriculture   machine ry — Methods of sampling . 
3 Terms and definitions  
For the purposes of this standard, the terms and definitions given in RS 2 68-4 and the following shall apply.  
3.1 
airflow rate  
volume of air in cubic meters delivered to the mass of grains per second  
3.2 
burner efficiency  
furnace efficiency ratio of the heat supplied by the burner/furnace, to the heat released by the fuel  
3.3 
drying air temperature  
mean temperature of the air to be used for drying the grain, measured at a number of points as close as 
practicable to its entry to the grain bed  DRS 269-4: 2020  
vii                ©RSB 2020  - All rights reserved  
 3.4 
drying system efficiency  
ratio of the total heat utilized for drying, to the heat available in the fuel expressed in percent  
3.5 
grain holding capacity  (syn: load capacity continuous flow dryer)  
weight of grain  in the dryer after a period of stable operation batch type dryer: weight of grain required to fill 
the dryer at the input moisture content  
3.6 
purity  
percentage of grains free of foreign matter  
3.7 
scattered grains  
ratio of the weight of grains that fell out from the machine during the drying operation, to the weight of the total 
grain input to the dryer, expressed in percent  
3.8 
tempering  
temporarily holding the grain between the drying passes, allowing the moisture content in the centre of the 
grain and that on the surface of the grain to equalize  
4 General conditions for test and inspection  
4.1 Machine on test  
4.1.1  The machine on test shall be commercially produced or prototype unit or slightly used machine 
depending upon the test objective.  
4.1.2  In case of  testing commercially manufactured dryers, the dryer sampled for acceptance, lot, routine, 
and type tests in accordance with RS 241 shall be submitted for test.  
4.2 Role of manufacturer/dealer  
The manufacturer/dealer shall comply with the test procedures of national testing authority.  DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  viii 
 4.3 Test site conditions  
The dryer shall be tested as installed for normal operation. The site shall have adjacent to its premises 
suitable space for storing and turning a sufficient quantity of grains for drying during the test . 
4.4 Measurement  of dryer holding capacity  
4.4.1  The maximum amount of grain required to fill the dryer for proper operation shall be verified when 
filling the dryer at the beginning of the test.  
4.4.2  The holding capacity shall be measured in terms of weight and other accompanying information such 
as moisture content and purity.  
4.5 Indication  of damage  
4.5.1  Samples of grain used for the test shall be subjected to laboratory analysis by test milling and 
presence of cracked grains before and after drying.  
4.5.2  Milling test of the samples obtained during drying test shal l be conducted at least 48 h  after the drying 
test while air -dried samples shall be milled when its moisture content reaches 13.5%  
4.6 Suspension  of test  
4.6.1  If during the test run, the machine stops due to breakdown or malfunction so as  to affect the 
machine’s performance, the test shall be suspended.  
4.6.2  The decision to suspend or to continue the test is at the discretion of the test engineer and concurre d 
by the company representative.  
5 Test prepa ration  
5.1 Materials and equipment  
5.1.1  Fuel 
The fuel to be used shall conform to the specification supplied by the manufacturer  and comply with Rwanda 
standards  on petroleum product  
5.1.2  Grain  
The grain to be used shall be single variety and the moisture content shall be 20% and above for rice and corn 
with the highest available moisture content to be used in the test.  
5.1.3  Measuring instruments  
The measuring instruments for performance testing shall be calibrated prior to the tests.  DRS 269-4: 2020  
ix                ©RSB 2020  - All rights reserved  
 5.2 Test set -up 
5.2.1  Thermometers shall be m ounted on or inside the dryer for temperature sensing.  
5.2.2  Thermometers shall be mounted at least at the following locations:  
a) near the dryer to sense ambient temperature;  
b) at the grain plenum interface;  
c) after the plenum; and  
d) immediately outside the dr yer to sense exhaust air temperature.  
5.2.3  Temperature sensors shall be partially shielded to minimize errors from heat radiation effects.  
5.2.4  A schematic diagram shall be made of the dryer, showing a numbered location for each sensor.  
5.2.5  For the measurement of airflow and static pressure, pitot tube and manometer or any other suitable 
apparatus shall be installed.  
5.2.6  The control of drying air condition shall be by adjustment of the setting of an automatic control forming 
part of the dryer, or b y manual adjustment of the furnace if automatic temperature control mechanism is not 
fitted.  
5.2.7  Adjustments for the purpose of maintaining a steady temperature of the drying air may be made at 
any time but any adjustment of an automatic control shall ha ve been sanctioned by the Testing authority.  
5.2.8 Fire protection  complying with requirement of Rwanda standards on fire safetyshall be provided  
5.3 Running -in and preliminary adjustments  
5.3.1  The dryer shall be run -in in accordance with manufacturer’s operating manual before the start of 
actual test.  
5.3.2  The manufacturer may take any adjustment during the period of run -in. Adjustments shall be within 
the limits specified by the manufacturer . 
6 Procedures of test  
6.1 Verification of the specifications  
6.1.1  This inspection is carried out to verify the mechanism, main dimensions, material and accessories of 
the dryer conform to the lists of specifications submitted by the manufacturer .  
6.1.2  Besides  gathering of technical data of the machine, observations on the following shall be made:  DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  x 
 a) quality of manufacture;  
b) adequacy of protection of components (e.g. bearings, shafting, belts, etc.);  
c) presence of safety controls;  
d) presence of dust collection systems;  and 
e) instruction manual and spare parts catalogue, and mechanical tool kit required.  
6.1.3  The items to be measured, inspected and observed shall be recorded in Annex A or Annex B . 
6.2 Performance  test 
6.2.1  This is carried out to test the performance of the g rain dryer.  
6.2.2  Three test trials shall be carried out with the same operational setting.  
6.2.3  The length of the test shall be such that one full capacity of grain has been dried to a final moisture 
content of the grain as specified in the concerned pr oduct standard . 
6.2.4  The dryer shall be operated at the drying air temperature as specified by the manufacturer.  
6.2.5  In case of continuous flow type dryer, the dryer’s discharge mechanism shall be set as specified by 
the manufacturer and the grains shal l undergo tempering process as the case for at least four (4) hours before 
reloading to the dryer for another pass.  
6.2.6  For a continuous drying operation, the minimum amount of test material to be used shall be equal to 
twice the rated capacity.  
6.2.7  The following shall be measured at least 30 -min intervals or as necessary : 
a) air velocity: Measurement of air velocity shall be made at the air duct or at the heat exchanger, whichever 
is applicable;  
b) temperatures: Grain temperature, drying air temperature, a mbient and exhaust air wet bulb and dry bulb 
temperatures shall be recorded;  
c) static pressure: This shall be taken at the plenum/transition duct;  
d) moisture content reduction per pass: In case of continuous flow dryer, the percentage of moisture 
removed for e ach drying pass shall be recorded;  
e) sound level: This shall be measured with the dryer full of grain, operating at recommended settings of 
different components, with burner on.;  DRS 269-4: 2020  
xi                ©RSB 2020  - All rights reserved  
 f) moisture content: Samples for moisture determination shall be taken at the bott om, middle and top layer 
of the grain for batch type dryers and from the flow of grain from the discharge mechanism for the 
continuous flow dryer;  
g) power and fuel: Measurement shall be made of the power and fuel used during each test run; and  
h) for determinat ion of grain quality, such as cracked grain and for milling test (in case for rice), samples 
from the input and final output shall be taken during each test run.  
6.2.7  The items to be measured, inspected and observed shall be recorded in Annex C.  
7 Ease of h andling and safety feature  
7.1 The ease of loading and unloading of grain operation, setting and adjustment shall be observed during 
the test and reported.  
7.2 The design from the point of view of safety for the operator and the different machine componen ts/ 
assemblies shall be checked and reported. These shall be recorded in Annex A or Annex B.  
8 Laboratory analysis of dried samples  
8.1 This is carried out to have a comparative analysis of the grains used before and after the drying test.  
8.2 The quality of  dried grain samples from the dryer shall be compared to the quality of dried grain using 
shade drying.  
8.3 The grain samples taken before and after the test shall be subjected to quality analysis in the 
laboratory.  
8.4 The following shall be determined:  
a) Variety;  
b) moisture content;  
c) purity;  
d) cracked grains;  
e) broken /split kernels;  
f) immature grains;  
g) fermented grains;  
h) damaged grains;  DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xii 
 i) foreign matter; and  
j) weed seeds  
8.5 Items to be determined shall be recorded in Annex D  
9 Formula  
The formula to be used during calculations and testing are given in Annex E.  
Test report  
The test report shall include the following information:  
a) title; 
b) summary;  
c) scope of test;  
d) method of test;  
e) condition of machine;  
f) description of the machine;  
g) results and discussion;  
h) observations (inclu de pictures); and  
i) names and signatures of test Engineers  
 DRS 269-4: 2020  
xiii                ©RSB 2020  - All rights reserved  
 Annex  A 
(normative)  
 
Specification of grain dryers (Continuous flow types)  
Name of Applicant (or Distributor): _____________________________________________  
Address: ______________________________________ _____________________________  
Tel. No.: ___________________________________________________________________  
Name of Manufacturer: _______________________________________________________  
Address: _____________________________________________________________ ______  
Tel. No.: ___________________________________________________________________  
General information:  
Mark:_____________________________ Model: ________________________________  
Serial No.: __________________________ Classification: __________________________  
Production date of dryer to be tested: _____________________________________________  
Testing A uthority : ________________Date of Testing: _________________________  
Test Engineer: ______________________  
Table A 1 — Grain dryer spec ification  
Items  Manufacturer’s 
Specifications  Actual  
Measurement/  
Inspection by the  
Testing A uthority  
A.1 Grain flow rate (t/h)*    
A.2. Drying chamber    
A.2.1 Drying and cooling section    
A.2.1.1 Overall dimensions (mm)    
Length    
Width    
Height    DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xiv 
 A.2.1.2 Grain holding capacity    
Volumetric (m3)    
Weight (kg.)    
A.2.1.3 Materials of construction    
A.2.2 Grain discharge section    
A.2.2.1 Metering device    
Type    
Number of elements    
Control drive arrangement    
Drive unit (kW)    
A.2.2.2 Materials of construction of discharge hopper    
A.3 Air distribution system    
A.3.1 Drying and cooling section    
A.3.1.1 Plenum    
a. Intake manifold    
Material (s) of construction    
b. Exhaust manifold    
Material (s) of construction    
A.3.1.2 Ducting    
Material (s) of construction    
A.3.2 Fans    
A.3.2.1 Drying and Cooling Section    
a Number    
b Type    
c Make and Model    
d Electric Motor    
d.1 Number and Type    
d.2 Total Rated Power (kW)    
d.3 Rated speed (rpm)    
d.4 Phase    
d.5 Voltage (V)    
d.6 Frequency (Hz)    
e Fan shaft speed (rpm)    
f Air flow rate (m3/min)    
A.4. Heating system    
A.4.1 Main    
A.4.1.1 Type (direct or indirect)    
A.4.1.2 Type of fuel    DRS 269-4: 2020  
xv                ©RSB 2020  - All rights reserved  
 A.4.1.3 Temperature control    
A.4.1.4 Fuel consumption (L/h)    
A.4.1.5 Other feature(s)    
A.4.2 Supplementary    
A.4.2.1 Type (direct or indirect)    
A.4.2.2 Fuel    
A.4.2.3 Temperature control    
A.4.2.4 Other feature(s)    
A.5. Tempering bin(s)    
A.5.1 Number    
A.5.2 Holding capacity (m3)    
A.5.2.1 Type    
A.5.2.2 Unloading rate (kg/h)    
A.5.3 Material(s) of construction    
A.5.4 Other feature (s)    
A.6. Material handling system    
A.6.1 Dump pit    
A.6.1.1 Pit dimension    
A.6.1.2 Material(s) of construction    
A.6.1.3 Feature (s)    
A.6.2 Elevator (s)    
A.6.2.1 Number and height (m)    
A.6.2.2 Capacity (t/h)    
A.6.2.3 Belt dimensions (w x t, mm)    
A.6.2.4 Elevator buckets    
A.6.2.4.a Dimensions (mm)    
A.6.2.4.b Material (s) of construction    
A.6.2.5 Drive Motor    
A.6.2.5.a Type    
A.6.2.5.b Rated power (kW)    
A.6.2.5.c Rated speed (rpm)    
A.6.2.5.d Phase    
A.6.2.5.e Voltage (V)    
A.6.2.5.f Frequency (Hz)    
A.6.2.6 Material (s) of construction    
A.6.2.7 Other Feature (s)    
A.6.3 Conveyor (s)    
A.6.3.1 Type    DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xvi 
 A.6.3.2 Number    
A.6.3.3 Capacity (t/h)    
A.6.3.4 Drive motor    
A.6.3.4.a Type    
A.6.3.4.b Rated power (kW)    
A.6.3.4.c Rated speed (rpm)    
A.6.3.4.d  Phase    
A.6.3.4.e Voltage (V)    
A.6.3.4.f Frequency (Hz)    
A.6.3.5 Control (s)    
A.6.3.6 Material (s) of construction    
A.6.3.7 Other feature (s)    
A.6.4 Other types of material handling    
A.6.4.1 Description    
A.7 Instruments and controls    
A.7.1 Temperature , moisture and    
pressure    
A.7.1.1 Air temperature    
A.7.1.1.a Type (s)    
A.7.1.1.b Location (s)    
A.7.1.2  Grain temperature    
A.7.1.2.a Type (s)    
A.7.1.2.b Location (s)    
A.7.1.2 Grain moisture content    
A.7.1.2.a Type (s)    
A.7.1.2.b Location (s)    
A.7.1.3 Pressure/ airflow indicator (s)    
A.7.1.2.a Type (s)    
A.7.1.2.b Location (s)    
A.7.1.4 Other  feature (s)    
A.8 Pre -cleaner    
A.8.1 Type    
A.8.2 Capacity    
A.8.3 Fan    
A.8.3.1 Type    
A.8.3.2 Material (s) of construction    
A.8.4 Sieve    
A.8.4.1 Type    DRS 269-4: 2020  
xvii                ©RSB 2020  - All rights reserved  
 A.8.4.2 Number    
A.8.4.3 Size of perforations (mm)    
A.8.4.4 Material (s) of construction    
A.8.5 Air Duct    
A.8.5.1 Diameter (mm)    
A.8.5.2 Material (s) of construction    
A.8.6 Electric Motor    
A.8.6.1 Type    
A.8.6.2 Rated power (kW)    
A.8.6.3 Rated speed (rpm)    
A.8.6.4 Phase    
A.8.6.5 Voltage (V)    
A.8.6.6 Frequency (Hz)   
A.8.7 Other feature (s)    
A.9 Dust emission control (s)    
A.9.1 Type (s)    
A.9.2 Location (s)    
A.9.3 Other feature (s)    
A.10 Safety feature (s)    
A.10.1 Product safety    
A.10.2 Machine safety    
A.10.3 Operation and maintenance safety    
* based on input to the dryer  
The following are to be filled -up by the testing authority  
A.12  Comments on the quality of manufacture  
_____________________________________________________________________  
_____________________________________________________________________  
A.13  Comments on adequacy of protection of components (e.g. bearings, shafting, belts, etc.)  
_____________________________________________________________________  
_____________________________________________________________________  
A.14  Comments on safety controls/devices  
_____________________________________________________________________  DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xviii 
 _____________________________________________________________________  
A.15  Comments on dust collection systems  
_____________________________________________________________________  
_____________________________________________________________________  
A.16  Availability of manuals, brochure, and standard and special tools for adjus tmentsand repair  
_____________________________________________________________________  
_____________________________________________________________________  
A.17  Comments on instrumentation  
__________________________________________________________________ ___ 
_____________________________________________________________________  
A.18  Comments on ease of loading and unloading  
_____________________________________________________________________  
_____________________________________________________________________  
A.19  Comments on settings and adjustments  
_____________________________________________________________________  
_____________________________________________________________________  
A.20  Other comments/ observations  
_____________________________________________________________________  
_____________________________________________________________________  DRS 269-4: 2020  
xix                ©RSB 2020  - All rights reserved  
 Annex  B 
(normative)  
 
Specification for grain dryers (batch type)  
Name of Applicant (or Distri butor): _____________________________________________  
Address: ___________________________________________________________________  
Tel. No.: ___________________________________________________________________  
Name of Manufacturer: _________________________ ______________________________  
Address: ___________________________________________________________________  
Tel. No.: ___________________________________________________________________  
General information:  
Make:_____________________________    Model: ____ ____________________________  
Serial No.: __________________________  Classification: __________________________  
Production date of dryer to be tested: _____________________________________________  
Testing A uthority : ________________            Date of Test ing: _________________________  
Test Engineer: ______________________  
Table B 1 — Grain dryer specification (batch type)  
Items  Manufacturer’s 
Specifications  Actual  
Measurement/  
Inspection by the  
Testing A uthority  
B.1. Machine Specifications    
B.1.1 Drying  Rate ( kg/h)    
B.1.2 Machine Structure    
B.1.2.1 Overall Dimensions (mm) (installed)    
B.1.2.1.a Length    
B.1.2.1.b Width    
B.1.2.1.c Height    DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xx 
 B.1.3 Drying Bin    
B.1.3.1 Type    
B.1.3.2 Dimensions (mm)    
B.1.3.2.a Length    
B.1.3.2.b Width/ Diameter    
B.1.3.2.c Height    
B.1.3.3 Holding Capacity (kg)    
B.1.3.4 Maximum Grain Depth*(mm)    
B.1.3.5 Material    
B.1.3.5.a Frame    
B.1.3.5.b Holding Bin    
B.1.3.5.c Wall    
B.1.4 Fan    
B.1.4.1 Type    
B.1.4.2 Brand/Model    
B.1.4.3 Air Flow Rate  (m3/min)    
B.1.4.4 Static Pressure (Pa)    
B.1.4.5 Material    
B.1.4.6 Prime mover    
B.1.4.7 Others (specify)    
B.1.5 Heater    
B.1.5.1 Type    
B.1.5.2 Brand/Model    
B.1.5.3 Fuel    
B.1.5.4 Heat output (kJ/h)    
B.1.5.5 Fuel Consumption (kg/h or L/h)    
B.1.5.6 Capacity of fuel tank (L)    
B.1.5.7 Method of temperature control    
B.1.5.9 Materials of construction    
B.1.5.10 Others (specify)    
B.1.6 Material Handling System**    
B.1.6.1 Dump Pit    
B.1.6.1.a Pit Dimension,L x W x H mm    
B.1.6.1.b Material(s) of construction    
B.1.6.1.c Other Feature (s)    
B.1.6.2 Elevator (s)    
B.1.6.2.a Number and Height (m)    
B.1.6.2.b Capacity (t/h)    DRS 269-4: 2020  
xxi                ©RSB 2020  - All rights reserved  
 B.1.6.2.c Belt dimensions (w x t, mm)    
B.1.6.2.d Elevator buckets    
B.1.6.2.d.1 Dimensions (mm)    
B.1.6.2.d.2 Material (s) of construction    
B.1.6.2.e Drive Motor    
B.1.6.2.e.1 Type    
B.1.6.2.e.2 Rated power (kW)    
B.1.6.2.e.3 Rated speed (rpm)    
B.1.6.2.e.4 Phase    
B.1.6.2.e.5 Voltage (V)    
B.1.6.2.e.6 Frequency (Hz)    
B.1.6.2.f Material (s) of construction    
B.1.6.2.g Other Feature (s)    
B.1.7 Safety Feature (s)    
B.1.7.1 Product Safety    
B.1.7.2 Machine Safety    
B.1.8 Operator Safety    
The following items are  to be filled -up by the Testing Authority  
B.3 Comments on the quality of manufacture  
_____________________________________________________________________  
_____________________________________________________________________  
B.4 Comments on adequacy of protection of components (e.g. bearings, shafting, belts, etc.)  
____________ _________________________________________________________  
_____________________________________________________________________  
B.5 Comments on safety controls/devices  
_____________________________________________________________________  
__________________ ___________________________________________________  
B.6 Comments on dust collection systems  
_____________________________________________________________________  DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xxii 
 _____________________________________________________________________  
B.7 Availability of manuals, brochure, and standard and special tools for adjustmentsand repair  
_____________________________________________________________________  
_____________________________________________________________________  
B.8 Comments on instrumentation  
________ _____________________________________________________________  
_____________________________________________________________________  
B.9 Comments on ease of loading and unloading  
_____________________________________________________________________  
________ _____________________________________________________________  
B.10  Comments on settings and adjustments  
_____________________________________________________________________  
_____________________________________________________________________  
B.11  Other c omments/ observations  
_____________________________________________________________________  
_____________________________________________________________________  DRS 269-4: 2020  
xxiii                ©RSB 2020  - All rights reserved  
 Annex  C 
(normative)  
 
Drying performance test  
C.1 Crop conditions  
C.1.1  Kind/Variety      : ________________________  
C.1.2  Initial grain moisture content (%)   : ________________________  
C.1.3  Total weight of grain (kg)    : ________________________  
C.1.4  Cracked grain (%)     : ________________________  
C.1.5  Damaged grain (%)     : _____________ ___________  
C.1.6  Impurities (%)     : ________________________  
C.2 Ambient conditions  
C.2.1  Temperature      : ________________________  
C.2.1.1  Dry bulb (oC)     : ________________________  
C.2.1.2  Wet bulb (oC)     : ________________________  
C.2.2  Relative humidity (%)    : ________________________  
C.2.3  Atmospheric pressure (Pa)    : ________________________  
C.3 Dryer performance  
C.3.1  Drying rate (kg/batch or kg/hr)   : ________________________  
C.3.2  Drying air temperature (oC)    : __________________ ______  
C.3.3  Ave. ambient air temperature (oC) 
C.3.3.1  Wet bulb      : ________________________  
C.3.3.2  Dry bulb      : ________________________  DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xxiv 
 C.3.4  Ave. ambient air relative humidity (%)  : ________________________  
C.3.5  Ave. exhaust air temperature (oC)   : ________________________  
C.3.5 .1 Wet bulb      : ________________________  
C.3.5.2 Dry bulb      : ________________________  
C.3.6  Ave. exhaust air relative humidity (%)  : ________________________  
C.-3.7 Ave. grain temperature (oC)    : ________________________  
C.3.8  Ave. air velocity (m/s)    : ________________________  
C.3.9  Ave. static pressure (Pa)    : ________________________  
C.3.10  Burner fuel consumption (L/h)   : ________________________  
C.3.11  Electrical power consumption (kW)   : ________________________  
C.3.12  Drying time (h)     : ________________________  
C.3.13  Moisture content reduction  per pass or per batch (%/h)    : ________________________  
C.3.14  Drying system efficiency (%)   : ________________________  
C.3.15  Burner/furn ace efficiency (%)   : ________________________  
C.3.16  Heating system efficiency (%)    : ________________________  
C.3.17  Heat utilization (KJ/kg of H 2O)   : ________________________  
C.3.18  Dryer efficiency (%)     : ________________________  
C.3.19  Moisture  content (% w.b.)    : ________________________  
C.3.20 Moisture content gradient (%)   : ________________________  
 
 DRS 269-4: 2020  
xxv                ©RSB 2020  - All rights reserved  
 Annex  D 
(normative)  
 
Laboratory analysis of samples  
D.1 Analysis of paddy samples  
Laboratory milling of rice shall b e conducted, minimum of 48 h  after drying.  
Machine tested: _______________________  
Variety: _______________________  
Laboratory analyst : _______________________  
Date of test: _______________________  
Table D 1 — Analysis of paddy samples  
Conditio
n Moistur
e 
Conten
t 
(%) Bulk  
Densit
y 
(kg/m3
) Purit
y (%)  Foreig
n 
Matter 
(%) Cracke
d 
Grains 
(%) Immatur
e 
Grains 
(%) Weed  
Seeds 
(%) Fermente
d 
Grains  
 (%) Damage
d 
Grains  
 (%) Remarks  
Before 
Drying            
After 
Drying            
Table D .2 — Analysis of milled rice  
Condition  Head  
Rice 
(%) Broken  
Rice 
(%) Milling  
Recovery 
(%) Whiteness  
Index  Milling  
Degree  Date 
of 
Test Moisture  
Content 
(%) Remarks  
Air Dried 
or 
Laboratory 
Dryer          
Dryer on 
Test         
 
 DRS 269 -4: 2020  
©RSB 2020 - All rights reserved                  xxvi 
 D.2 Analysis of maize samples  
Machine tested : _______________________        
Variety :                 _______________________     
Laboratory analyst : _______________________  
Date of test :     _______________________  
Table D. 3 — Analysis of maize samples  
Condition  Moisture 
Content 
(%) Bulk 
Density  
(kg/m3)  Purity 
(%) Foreign 
matter 
(%) Cracked 
Grains 
(%) Damaged 
Grains  
 (%) Remarks  
Before 
Drying         
After 
Drying         
 
 
 
 DRS 269-4: 2020  
xxvii                 ©RSB 2020  - All rights reserved  
 Annex  E 
(normative)  
 
Formula to be used in computation of drying parameters  
j) Drying capacity (kg/h) =𝐼𝑛𝑖𝑡𝑖𝑎𝑙  𝑤𝑒𝑖𝑔 ℎ𝑡 𝑜𝑓 𝑡𝑒𝑠𝑡  𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙  (𝑘𝑔)
𝐴𝑐𝑡𝑢𝑎𝑙  𝑑𝑟𝑦𝑖𝑛𝑔  𝑡𝑖𝑚𝑒  (ℎ) 
k)  weight of test material, 𝑊2(kg) 
𝑊2=𝑊1(100 −𝑀𝐶1)
(100 −𝑀𝐶2) 
l) Moisture reduction per hour  
By weight (kg/h) =𝐼𝑛𝑖𝑡𝑖𝑎𝑙  𝑤𝑒𝑖𝑔 ℎ𝑡 𝑜𝑓 𝑡𝑒𝑠𝑡  𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙  (𝑘𝑔)−  𝐹𝑖𝑛𝑎𝑙  𝑤𝑒𝑖𝑔 ℎ𝑡 𝑜𝑓 𝑡𝑒𝑠𝑡  𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙  (𝑘𝑔)
𝐴𝑐𝑡𝑢𝑎𝑙  𝑑𝑟𝑦𝑖𝑛𝑔  𝑡𝑖𝑚𝑒  (ℎ) 
m) Heating system efficiency (%)  
HSE =𝐻𝑒𝑎𝑡  𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑  𝑡𝑜 𝑡ℎ𝑒 𝑑𝑟𝑦𝑒𝑟
𝐻𝑒𝑎𝑡  𝑎𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒  𝑖𝑛 𝑡ℎ𝑒 𝑓𝑢𝑒𝑙×100 
Where:  
Heat supplied =[𝐸𝑛𝑡 ℎ𝑎𝑙𝑝𝑦  (ℎ2)− 𝐸𝑛𝑡 ℎ𝑎𝑙𝑝𝑦  (ℎ1)]×𝑎𝑖𝑟 𝑓𝑙𝑜𝑤  𝑟𝑎𝑡𝑒  (𝑚3
𝑚𝑖𝑛)
𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐  𝑣𝑜𝑙𝑢𝑚𝑒  (𝑚3
𝑘𝑔𝑑𝑟𝑦  𝑎𝑖𝑟)×60𝑚𝑖𝑛
ℎ 
Heat available =𝐹𝑢𝑒𝑙  𝑓𝑒𝑒𝑑  𝑟𝑎𝑡𝑒  (𝑘𝑔
ℎ)×ℎ𝑒𝑎𝑡𝑖𝑛𝑔𝑣𝑎𝑙𝑢𝑒  𝑜𝑓 𝑓𝑢𝑒𝑙  (𝑘𝐽
𝑘𝑔) 
n) Heat utilization (kJ/ kg)=𝐻𝑒𝑎𝑡  𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑  (𝑘𝐽
ℎ)×𝑑𝑟𝑦𝑖𝑛𝑔𝑡𝑖𝑚𝑒  (ℎ)
𝐴𝑚𝑜𝑢𝑛𝑡  𝑜𝑓 𝑚𝑜𝑖𝑠𝑡𝑢𝑟𝑒  𝑟𝑒𝑚𝑜𝑣𝑒𝑑  (𝑘𝑔)×100 
o) Drying efficiency (%) =𝑇𝑜𝑡𝑎𝑙  ℎ𝑒𝑎𝑡 𝑢𝑡𝑖𝑙𝑖𝑧𝑒𝑑  (𝑘𝐽
ℎ)
𝐻𝑒𝑎𝑡  𝑠𝑢𝑝𝑝𝑙𝑖𝑒𝑑  𝑡𝑜 𝑡ℎ𝑒 𝑏𝑢𝑟𝑛𝑒𝑟  (𝑘𝐽
ℎ)×100 
p) Combusti on efficiency (%) =𝐻𝑒𝑎𝑡  𝑟𝑒𝑙𝑒𝑎𝑠𝑒𝑑  𝑏𝑦 𝑡ℎ𝑒 𝑓𝑢𝑒𝑙  (𝑘𝐽
ℎ)
𝐴𝑚𝑜𝑢𝑛𝑡  𝑜𝑓 𝑓𝑢𝑒𝑙  (𝑘𝑔
ℎ)×ℎ𝑒𝑎𝑡𝑖𝑛𝑔𝑣𝑎𝑙𝑢𝑒  𝑜𝑓 𝑓𝑢𝑒𝑙  (𝑘𝐽
𝑘𝑔)×100 
Drying system efficiency (% )=𝑇𝑜𝑡𝑎𝑙  ℎ𝑒𝑎𝑡 𝑢𝑡𝑖𝑙𝑖𝑧𝑒𝑑  (𝑘𝐽
ℎ)
𝐴𝑚𝑜𝑢𝑛𝑡  𝑜𝑓 𝑓𝑢𝑒𝑙  (𝑘𝑔
ℎ)×ℎ𝑒𝑎𝑡𝑖𝑛𝑔𝑣𝑎𝑙𝑢𝑒  𝑜𝑓 𝑓𝑢𝑒𝑙  (𝑘𝐽
𝑘𝑔)×10RS 269-4: 2020  
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  DRS 269 -4: 2020  
 
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