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66 Wschodnioeuropejskie Czasopismo Naukowe (East European Scientific Journal)#3(19), 2017 HSkl
Pulatova Dilnoza Mannanovna, Tashkent State
Technical University, Assistant, Department Power engineering
RESEARCH OF SPEED OF THE STREAM AIR + THE FIRM CORPUSCLE IN THE DIFFUSOR
WITH BOILEDAND SPOUTING LAYER
Annotation: In article is considered research of speed of the stream air + the firm corpuscle in the diffusor with boiled and spouting layer. The Ghost thorough scheme experimental installation. Using new instruments for determination of the velocities mixture and pressures. The Graphic determination to profiles to velocities in each section on height 10 refer to specified to installation. Specifydependency event fountain of the hard particles of model backfilling from intensity of the turbulences of the flow.
Keywords: air flow rate, fluidized bed, particulate filling model, turbulence.
The article deals with the study of air flow rate + solid particle in the diffuser with the fluidized and spouted bed. The scheme of the experimental installation. The modern instruments for determining the mixture of speed and pressure have been applied. The speed profiles are graphically determined at the height of 10 cm at each section of the installation. The dependence of the model filling on the intensity of turbulence in case of spouting of solid particles has been determined.
The experience of study the history of the science shows that progress in the field of heat transfer mechanics by canal the intensification of burning Angren coal at various stages of its development has always been driven and to a large extent has been determined by the developments in the experimental studies. It is crucial to emphasize the significance of hydro - aerodynamics experiment in creating and testing different burners, boilers and construction designs, as well as their individual components.
The main issues of interest to designers when considering the motion of a fluid and gas in the pipes - is the velocity distribution and head loss in cross-section.
Experiments show that as the velocity distribution and the pressure loss can vary widely depending on the pipe diameter, the velocity, the fluid viscosity and the roughness of the pipe wall, as well as the concentration of solid impurities in liquids and gases.
Recently, due to the restriction of the natural gas use energy engineering is the topical issue of the replacement of natural gas by the low-rank brown coal. One effective way of burning low-rank coal described in [1] that spouted fluidized bed is more effective than other methods of burning low-rank Angren coal. The results of the two-phase hydrodynamic studies in a conical spouted bed apparatus are presented in details in [2].
The studies were conducted on the experimental single-chamber installation synthesized boiling layers [2]. In this setting, a fixed bed (PS-Pump station) has been formed at the installation the model study Sunflower seeds after frying were used as solid particles. The height of the fixed bed was varied within 10 ^ 25 cm.
The fixed layer is a set of curving and communicating channels of variable section. The instant fluid and gas velocity in this layer may reach quite high values.
Gas motion in a PS compared with the conventional turbulent motion is significantly different, since
the thread PS in these conditions is a complex non-stationary pulsed current, a consisting of high-speed jets flowing into the neighbor units in diffuser the PS vin a indisctiminate way. Thus, fluid flow in the apparatus is a fixed bed, modifying the structure and movement of the liquid gas.
Experimental research and visual observations of the mixtures' movement in the pipelines and canals provide a basis for selecting the hydrodynamic model at the study of the theory of mixture combustion of finely dispersed solid particles. Due to the - lack of a general theory of various combustions, individual hydrodynamic models are used: quasi-homogeneous (uniformly similar), interpenetrating, geterogenic (multiphase), etc. The course is regarded as quasi-homogeneous environment with the averased parameters and described with the equations which parameters to some extent are calculated using expressions that are not common to all sorts of mixtures, which are appropriate for the particular case of combustion. In particular, for the motion of the dispersed particles of Angren coal.
The aim of this work is the experimental determination of the change rate of the averaged two-phase flow at the diffuser length from the pressure drop and the flow cross-sections.
The single-chember experimental device is designed in order to study the structure of the movement of certain compounds in the vertical diffuser tube:
a) for visual observation and photography of the structure formation of vertical flow.
b) to calculate the distribution and nature of the solids concentration in the cross section of the diffuser.
c) to measure and determine the nature of the profile of the mean velocity over the cross section of the diffuser.
The installation consists of a conical shape of the working chamber 6 made of organic glass for visual observation of the fluid dynamics of the process.
Figure 1. The mounted fittings 8 are vertically installed for differential pressure measurement at every 10 cm On the camera body 6. Lower connection is posted on the gas flow entering the chamber. The stabilizer swirling gas flow is placed in the inlet pipe air supply tubes before the operation of the chamber. The diameter of the inlet port is 10 cm. The air supply to a chamber is prodused by fan 1, and the flow rate is regulated by a special divider 2. The measuring sensors are mounted in the nozzles 3 and 8.
Wschodnioeuropejskie Czasopismo Naukowe (East European Scientific Journal) #3(19), 2017
67
Fig. 1. The Diagram of the device experimental 1 fan; 2 air flow regulator air; 3, 8 - nozzles for measuring sensors; 4- air flow stabilizer; 5- retention grille; 6-
working chamber; 7 air outlet.
Meter Testo 405-V1, the differential micromanometer MCM-2400 and digital video camera GR-D850AS were used as instrumentation.
The mixture of sunflower seed components has been used as a model material(seeds- 80%, pod - 10%
and the pulp - 10%). The techniques for measuring flow rate are given in [2].
The first phase of the experiment is to remove the velocity field on the diffuser section with a fixed bed (sunflower seeds). The average flow rate of air was measured with modern instrument Testo 405-V1.
Fig. 2. Graphic dependence of the profile velocity of 10 sm model backfill. a) AP=20 Pa; b) AP=30 Pa; c) AP=45-50 Pa d) AP=60-70 Pa; f) AP=60-80 Pa. (fountain).
Differential pressure was measured with INN-2400. We measured field velocity in each section separately. After the statistical processing the values of average velocity up to the part of the installation are shown in Figure 2.
From Fig. 2. shows that the profile velocity is independent from the differential pressure and vary throughout cross section of the apparatus (cone). After spouting of solid particles turbulence intensity increases.
Literature
1. Karimov AA, Xidirova G.A., Babaxodjaev R.P., MukolyansA.A. Studing of hydrodynamics of the
two - phase gushing forth layer in the conic device // Zh.Europen applied sciences №3 2014 96-100 р.
2. Babakxadjayev R.P., Karimov A.A. Shakirov A.A. Hydrodynamic research of two-phase spouted bed in a conical apparatus // Herald TashSTU, Тashkent 2009., №3-4. 79-82 p.
Пулатова Дилноза Манноновна Место работы - Ташкентский Государственный Технический Университет Должность - ассистент Учёная степень - нет
