EKOR
Limited Liability Company
Research & Engineering Enterprise
The system for continuous monitoring
of the water mass fraction in the
ammonium nitrate melts
Director Dovgalov Leonid+380503287217
ISO
9001:2008
The system for continuous monitoring of the water mass
fraction in the ammonium nitrate melts (for one channel of
concentration measuring) consists of:





concentration sensor;
spark protection unit;
unit of signal normalization;
valve of refrigerant supply;
industrial PC with input-output boards.
2
The system for continuous monitoring of the water
mass fraction in the ammonium nitrate melts
Normalized
signallize
Unit of signal
normalization
Apparatus
wall
Signal
4-20 mA
Spark
protection
unit
Industrial PC
Control
Air
valve
Air
Temperature
Air
Temperature
sensor
Compressed
air
Concentration
sensor
3
Concentration
NH4NO3%
,%
Концентрация of
NH4NO3,
100
95
90
85
80
75
70
65
60
55
50
0
20
40
60
80
100
120
140
160
180
Температура,
Temperature,°С°C
Dependence between the temperature of crystallization of melt
and the water content in it is about 1,4°C for 0,1% weight of
water – is using for concentration determination.
4
Principle of the system
Method of determination of the water mass fraction consists in :
□ supplying of refrigerant to the concentration sensor and
measuring the temperature inside the sensor during cooling and
melt crystallization;
□ analysis of the measured dependence “temperature – time” in
the “sliding window”, crystallization temperature definition;
□ calculation of the water mass fraction in the ammonium
nitrate melt.
After determining of the crystallization temperature supply of
the refrigerant stops, the environment inside the concentration
sensor renews and the cycle repeats.
Time of cycle is about 10 min.
5
Temperature change of melt in the concentration
sensor
t, °С
Heating of melt Refreshing of solution
Switching –on of air
Crystallization point
Switching-off of air
Time, h
6
1,5
98,5
1,4
98,6
1,3
98,7
1,2
98,8
1,1
98,9
1,0
99,0
0,9
99,1
0,8
99,2
0,7
99,3
0,6
99,4
0,5
99,5
0,4
99,6
0,3
99,7
0,2
99,8
0,1
99,9
0,0
NH4NO
3 concentration
Концентрация
NH4NO3, %, %
Концентрация
H2O, % , %
H2O
concentration
Changes in the water mass fraction in the
ammonium nitrate melt
100,0
15
16
System
Система
17
Analysis
Анализ
7

The design of concentration sensor
provides :



even cooling and ammonium nitrate melt
crystallization in a closed space;
minimal cycle time of the crystallization
temperature determination.
Feature of the temperature sensor is the
minimal response time.
8
Software



controls the measurement process
displays the measured process parameters as trends and
numeric values;
allows to view the process history.
9
Metrological characteristics
Given value of
the mass
fraction of
water
Хистэ, %
0,10
Measured
value of the
mass fraction
of water
Хi, %
0,09
Average
measured value
of the mass
fraction of
water
Хср, %
Standar
d
deviatio
n
S, %
Random
component of
the absolute
error ∆случ., %
The systematic
component of
absolute error
∆с., %
Absolute
measurement error
∆,%
0,12
0,019
0,053
0,018
0,071
1,02
0,009
0,024
0,024
0,048
0,49
0,008
0,023
0,008
0,031
0,12
0,12
0,12
0,14
1,00
1,01
1,03
1,03
1,02
1,03
0,50
0,49
0,49
0,50
0,48
0,50
10
Metrological characteristics (5-15% of water)
Given value of
the mass
fraction of
water
Хистэ, %
5,00
Measured
value of the
mass fraction
of water
Хi, %
4,99
Average
measured value
of the mass
fraction of
water
Хср, %
Standar
d
deviatio
n
S, %
Random
component of
the absolute
error ∆случ., %
The systematic
component of
absolute error
∆с., %
Absolute
measurement error
∆,%
4,94
0,061
0,263
0,060
0,323
9,52
0,032
0,140
0483
0,624
0,49
0,144
0,618
0,843
1,461
4,99
4,84
10,00
9,49
9,57
9,49
15,00
14,39
14,02
14,06
11
Testing of the system for continuous monitoring of
the water mass fraction in the ammonium nitrate
melts



system was tested in the ammonium nitrate manufacture of
JSC “Severodonetsk Azot Association”;
at the same time sampling was carried out, and in accordance
with the "Methodology for measuring of ammonium nitrate
mass fraction in the melt by the crystallization temperature" №
МУ-38 was determined the concentration of the melt;
tests showed good convergence of measurements.
12
Changes in the ammonium nitrate mass fraction in
the melt pos.602/1
t, °C
С, %
170
167
164
161
158
155
152
149
146
143
140
137
134
131
128
125
122
119
116
113
110
100,0
99,8
99,6
99,4
99,2
99,0
98,8
98,6
98,4
98,2
98,0
97,8
97,6
97,4
97,2
97,0
96,8
96,6
96,4
96,2
96,0
0
1
2
3
4
5
6
7
8
9
Температура
Crystallization кристаллизации,
temperature, systemсистема
Ammonium
nitrate
concentration,
system
Концентрация селитры,
система
Schedule, minimum
Регламент, минимум
10
11
12
13
14
15
16
17
18
19
20
21
Температура
кристаллизации,
Crystallization temperature,
lab test лаб. анализ
Ammonium
nitrate
concentration,
lab test
Концентрация селитры, лаб. анализ
Schedule, maximum
Регламент, максимум
22
23
24
time,
время,hч
13
View of the instrument
part of system
The control system of water
mass fraction in the
ammonium nitrate melt is
introduced and successfully
operated on JSC “Azot”
(Cherkassy, Ukraine) and
PJSC “Concern “Stirol”
(Gorlovka, Ukraine).
14
Operation of the system for continuous monitoring
of the water mass fraction in the ammonium nitrate
melts in industrial conditions


system includes six monitoring points and controls the mass
fraction of water in the melt of ammonium nitrate after the
evaporation stage before granulation in the range of 0,1-2% of
water;
system is also used to control the solutions for making of
liquid ammonia fertilizer in the range of 8-10% of water.
15
Graphical screen of the system in viewing mode "for
a day" in the manufacture M-9 at the JSC “Azot“,
Cherkassy (for two monitoring points)
Mass
fraction of
the water
16
Graphic window of operator’s workplace

Measurement data of the water mass fraction is issued as a
signal of 4÷20 mА to the current APCS.
17
The proposed system allows to :




control the water mass fraction in the technological
ammonium nitrate solutions after the neutralization stage and
during the entire process;
control the final product quality(to reduce the number of
defects);
reduce the energy consumption for evaporation;
complete or replace the labor consuming and subjective
laboratory analysis with automatic measurement directly in the
ammonium nitrate melt.
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Calculation of the economic effect

By reducing the steam consumption(E1)
E1 = W·ΔС·М·P1 = 101192 UAH/year, or 20240 USD/year,
W = 1,3ton – amount of steam, required for evaporation of 1 ton of water from the melt of
ammonium nitrate in the range 93,0÷99,8%;
ΔС = 0,002 – difference(from99,8to99,6%)in the amount of evaporated water in a ton of
ammonium nitrate by more accurate maintenance of the concentration;
М = 400000ton/year – amount of produced ammonium nitrate;
P1 = 97,3UAH/ton –steam price.

By increasing the amount of produced commercial ammonium nitrate (E2)
E2 = ΔС·М·P2 =640000 UAH/year, or 128000 USD/year,
P2 = 800UAH/ton –ammonium nitrate price.

The total economic effect (E) of introduction of the system of continuous monitoring of
the mass fraction of water in the melt of ammonium nitrate :
E = E1 + E2 = 741192 UAH / year, or 148240 USD/year.
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Delivery of the system includes :






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system completing;
supervision of installation of sensors;
installation of sensors, instrument part of the system;
system adjustment;
delivery of technical description and operating instructions;
training of operating staff;
carrying out warranty tests, delivery of the system into
operation.
Mounting of sensor units and cable routing is performed by the
Customer.
The proposed system can be introduced during 4 months.
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