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In order to overcome these defects, we newly created a flow meter with several holes instead of one hole. The newly manufacted multi - hole orifice flowmeter has higher precision than the flowmeter with one hole and the stabilization distance of the flow after the flowmeter is short.
The flow rate in the orifice flowmeter is determined as follows [1].
Q = asF
2ap ,
- , m3/h (1)
V p
G = asF 2p AP , Kg/h (2)
Where Q- Volume in working state, m'/h a - flux coefficient
S - Flow Expansion Correction coefficient F- Cross-sectional area of fluid flow m2
△P - Differential pressure between before and after plate (aP=Pi-P2) P - Density of measuring medium at working temperature and working pressure Kg/ m The newly introduced multi - hole orifice flowmeter largely consisted of a flow - sensing unit, a drive circuit, a capacitive sensing unit, a micro - capacitance detection circuit, an amplifier circuit, a channel selector, an A / D converter and a computer.
The driving circuit consists of an oscillator, a divider, and a buffer amplifier (voltage repeater). To stabilize the frequency of the oscillation signal, a crystal was used for the oscillator and a frequency (500 kHz) signal was obtained in a frequency divider.
In the buffer amplifier, a voltage repeater is used so that the influence of the internal resistance of the signal power source on the micro-capacitance detection is reduced.
Like this by introducing a new multi-hole orifice flowmeter, the measurement accuracy can be further improved and the measurement can be scientifically developed.
References
1. Malavasi S., Messa G., Fratino U., Pagano A. On the pressure losses through perforated plates. Flow Measurement and Instrumentation, 2012. 28: P. 57-66.
PRODUCTION PROCESS OF STABILITY-ENHANCED BLASTING AGENT Kang H.N. (Democratic People's Republic of Korea) Email: [email protected]
Kang Hyo Nam - Candidate in mineral processing, Lecturer, DEPARTMENT OF MINERAL PROCESSING, CHONGJIN UNIVERSITY OF MINING AND METALLURGY ENGINEERING, CHONGJIN, DEMOCRATIC PEOPLE'S REPUBLIC OF KOREA
Abstract: in this paper described that we have newly established a production process of a blasting agent containing SMEA (synthetic fatty acid monoethanolamide) as a stabilizer, and described that large blasting is ensured by producing 70 t of blasting agent required for blasting of300 000MT.
By improving the stability of the blasting agent, not only the power of explosives was stably preserved, but the surfactant action of SMEA reduced the space rate in the ammonium nitrate, thereby increasing the loading density of the blasting agent by 8 %. Keywords: blasting agent, SMEA, explosive manufacturing.
УКРЕПЛЕНИЕ СТАБИЛЬНОСТИ ВЗРЫВЧАТЫХ ВЕЩЕСТВ Кан Х.Н. (Корейская Народно-Демократическая Республика)
Кан Хё Нам - кандидат наук обогащения полезных ископаемых, преподаватель, кафедра обогащения полезных ископаемых, Чхонджинский горно-металлургический институт, г. Чхонджин, Корейская Народно-Демократическая Республика
Аннотация: в этой статье описывается, что мы недавно установили процесс производства взрывчатого вещества, содержащего SMEA (моноэтаноламид синтетической жирной кислоты), в качестве стабилизатора, и описали, что большая взрывная работа обеспечивается получением 70 т взрывчатого вещества, необходимого для струйной обработки 300 000 МТ.
Благодаря повышению стабильности взрывчатого вещества не только стабильность взрывчатых веществ стабильно сохраняется, но действие поверхностно-активных веществ SMEA уменьшает объемную скорость в нитрате аммония, тем самым увеличивая плотность загрузки взрывчатого вещества на 8%.
Ключевые слова: взрывчатый агент, SMEA, взрывчатое производство.
УДК 331.225.3
1) Establishment of production process of stabilized blasting agent
The process for adding SMEA to diesel oil is shown in Fig 1.
First, add a certain amount of diesel oil and the required amount of SMEA to the mother liquor preparation tank (at this time, the concentration of SMEA in the diesel oil is 10%), indirectly heat it by hot water and raise the temperature to near 60 ° C. [1, p. 62]
diesel oil smea
1
■Г
oo
diesel oil
- mother lipuor preparation tank mother lipuor
o±o
diesel oil storage tank — blasting agent production process
Fig. 1. Process for adding SMEA to blasting agent
Stir with a stirrer while maintaining the temperature for 10 minutes.
It is then sent to a diesel oil storage tank to be diluted in whole diesel.
Next, SMEA-added diesel oil is sent to the blasting agent production process.
2) Technical and Economic Effectiveness
First, the physical stability of the blasting agent was enhanced.
It was lowed the interfacial tension of ammonium nitrate and diesel oil by adding synthetic fatty acid monoethanolamide (SMEA) to diesel oil for blasting agent without porosity and micro disintegration of ammonium nitrate and by increasing the viscosity of diesel oil, the flow of diesel oil in the blasting agent was delayed by the required amount of time according to the addition amount of SMEA and was improved its consolidation stability.
As a result, it was protected the diesel oil leaking in the production and transportation process of the blasting agent and was protected floating of the diesel oil in the loading space and was improved the effectiveness of large blasting agent. Also by regulating the added amount of SMEA the blasting agent used for the only one-day blasting agent could be maintained and used for a certain period of time.
The production process of the blasting agent with SMEA addition process is shown in Fig. 2.
ammonium nitrate diesel oil smea
t l i
ammonium nitrate crush SMEAdissolation
1 i mixing
I
weighing
T
packing
Fig. 2. Blasting agent production process adding SMEA
Second, the blasting density and explosive power of the blasting agent were increased.
By improving the stability of the blasting agent, not only the power of explosives was stably preserved, but the surfactant action of SMEA reduced the space rate in the ammonium nitrate, thereby increasing the loading density of the blasting agent by 8%.
As the density of charge increases, explosive work capacity increased by 10% on average, explosion rate by 9%, explosion pressure by 19% and specific power by 18.5% on average.
Table 1. Technical economic indicators of stabilized blasting agents
Indicators Unit Previous blasting Stabilized blasting
agent agent
Ammonium nitrate % 94 94
Composition diesel oil % 6 5.94~5.94
SMEA % - 0.03~0.06
Charge density (After 6 hours) g/cm' 1.05 1.13
Explosion temperature (After 6 hours) °c 1 926 2 790
Explosive gas pressure (After 6 hours) m 2 581 2 640
Work ability (After 6 hours) cm' 240 300
Explosion speed m/s 2 800 3 400~3 600
Diesel oil outflow stability 1 hours Over a week
Consolidation stability 3~4 day More than 20 days
Explosive non-consumption g/t 250 225
Third, the application effect of blasting agent was increased in the large open-air blast. By increasing the physical stability of the blasting agent and increasing its power, the blasting factor increased by 10% and the explosive non-consumption ratio decreased by 11% in the large blast of 30 million ton. Fourth, the production culture was guaranteed and the labor safety condition was improved. In the process of production of explosives, diesel oil leaking on the floor of the production site and diesel oil exuding from Explosive saddles eliminated, thus improved the working conditions of the workers and played an important role in establishing the production culture.
In addition, the risk of fire was reduced by preventing the diesel oil from leaking during the transportation of the blasting agent.
References
1. Institute of Makers of Explosives. The American Table of Distances. Safety Library Publication. № 2. Washington D.C.: IME.
