scholarly journals IMPROVEMENT OF DESIGN OF PNEUMATIC HAMMER FOR DRIVING VERTICAL PIPES WITH LARGE DIAMETER INTO SOIL

2020 ◽  
Vol 2 ◽  
pp. 219-225
Author(s):  
Vladimir V. Chervov
Keyword(s):  
Fatigue Failure ◽  
Distribution System ◽  
Work Performance ◽  
Large Diameter ◽  
Large Mass ◽  
Operating Principle ◽  
Main Element ◽  
Air Distribution ◽  
Pneumatic Hammer ◽  
Basic Parameters

A brief description of the equipment used for trenchless pipe laying is given. The basic parameters of a pneumatic hammer designed for driving pipes into soil with an open end greater than 426 mm in diameter are substantiated. The description of the device and operating principle of a pneumatic hammer with an air distribution system using an elastic circular valve as the main element is presented. Based on the analysis of many-year operation of equipment for trenchless pipe laying and driving vertical pipes, the frequency and sequence of crack appearance, destruction and failure of the main parts of the pneumatic hammer are determined. New principles of calculation and design of a pneumatic hammer with a large mass of the striking part without loss of work performance are proposed. The solution to the problems associated with fatigue failure of the main parts is a decrease in striking velocity.

scholarly journals CALCULATUION OF DYNAMIC PARAMETERS OF REVERSE CHAMBER OF PNEUMATIC HAMMER WITH MECHANICAL LOCKING OF ELASTIC VALVE

2019 ◽  
Vol 2 (5) ◽  
pp. 98-102
Author(s):  
Alexander Chervov
Keyword(s):  
Distribution System ◽  
Cylindrical Part ◽  
Short Description ◽  
Air Pressure ◽  
Air Distribution ◽  
Pneumatic Hammer ◽  
Elastic Valve ◽  
Working Chamber ◽  
Method Of Calculation ◽  
Exhaust Line

In paper short description of construction and functioning of pneumatic hammer with air distribution system based on application of elastic valve in exhaust line of reverse chamber is carried out. Using specified parameters of pneumatic hammer (percussion energy, percussion speed, ration of chamber squares, form of working chamber, compressed air pressure and etc.) mass of striking pin, working path, diameters of working chamber and cylindrical part of reverse chamber, dimensions of circle elastic valve are calculated. Proposed method of calculation considers change of cross-section of reverse chamber when striking pin moves back. Obtained calculated values have allowed to develop diagram chart of change of air pressure in reverse chamber in dependence on time.

CALCULATION OF STAGES OF THE TECHNOLOGICAL PROCESS OF MANUFACTURE OF PPD DETECTORS USING COMPUTER MATHEMATICAL MODELING AND PRODUCTION OF ALPHA RADIOMETER ON THEIR BASIS

2020 ◽  
Vol 7 (2) ◽  
pp. 21-28
Author(s):  
SALI RADZHAPOV ◽  
◽  
RUSTAM RAKHIMOV ◽  
BEGJAN RADZHAPOV ◽  
MARS ZUFAROV
Keyword(s):  
Mathematical Modeling ◽  
Technological Process ◽  
Block Diagram ◽  
Large Diameter ◽  
Silicon Detector ◽  
Digital Processing ◽  
Main Element ◽  
Alpha Radiation ◽  
Initial Silicon ◽  
Natural Isotopes

The article describes the developed radiometer for Express measurement of alpha radiation of radioactive elements based on a large-diameter silicon detector. The main element of the PPD detector is made using computer mathematical modeling of all stages of the technological process of manufacturing detectors, taking into account at each stage the degree of influence of the properties of the initial silicon on the electrophysical and radiometric characteristics of the detector. Detectors are manufactured for certain types of devices. The developed radiometer is designed to measure alpha radiation of natural isotopes (238U, 234U, 232Th, 226Ra, 222Rn, 218Po, 214Bi, etc.) in various environments. It also shows the principle of operation of the device, provides a block diagram of the measuring complex, describes the electronic components of the radiometer, as well as the block diagram. Signal transformations (spectrum transfer, filtering, accumulation) are implemented programmatically on the basis of a digital processing module. The device can detect the presence of specific elements in various environments, as well as protect people from the harmful effects of adverse radiation and can be used both in the field and stationary.

scholarly journals A CFD analysis of room aspect ratio on the effect of buoyancy and room air flow

2007 ◽  
Vol 11 (4) ◽  
pp. 79-94 ◽  
Author(s):  
Brajesh Tripathi ◽  
Moulic Sandipan ◽  
Late Arora
Keyword(s):  
Temperature Distribution ◽  
Distribution System ◽  
Air Distribution ◽  
Cooling Load ◽  
Cfd Analysis ◽  
Uniform Temperature ◽  
Air Volume ◽  
Recent Developments ◽  
Careful Design ◽  
Occupied Zone

Comfort conditions in air-conditioned rooms require that temperature in the occupied zone should not vary by more than 1?C and velocity, every where in the room, should be less than 0.15 m/s so that occupants do not feel draft. Recent developments in providing effective insulation and making leak tight buildings are considerably reduced the cooling load requirements and the supply airflow rates. Obtaining uniform temperature distribution with reduced air volume flow rates requires careful design of air distribution system. This study aims to find velocity and temperature distribution in the room towards this end.

scholarly journals Numerical Study on Coupled Operation of Stratified Air Distribution System and Natural Ventilation under Multi-Variable Factors in Large Space Buildings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8130
Author(s):  
Ziwen Dong ◽  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Hao Huang
Keyword(s):  
Thermal Comfort ◽  
Working Conditions ◽  
Distribution System ◽  
Distribution Systems ◽  
Natural Ventilation ◽  
Numerical Study ◽  
Air Distribution ◽  
Large Space ◽  
Air Conditioners ◽  
Air Supply

Stratified air distribution systems are commonly used in large space buildings. The research on the airflow organization of stratified air conditioners is deficient in terms of the analysis of multivariable factors. Moreover, studies on the coupled operation of stratified air conditioners and natural ventilation are few. In this paper, taking a Shanghai Airport Terminal departure hall for the study, air distribution and thermal comfort of the cross-section at a height of 1.6 m are simulated and compared under different working conditions, and the effect of natural ventilation coupling operation is studied. The results show that the air distribution is the most uniform and the thermal comfort is the best (predicted mean vote is 0.428, predicted percentage of dissatisfaction is 15.2%) when the working conditions are 5.9% air supply speed, 11 °C cooling temperature difference and 0° air supply angle. With the coupled operation of natural ventilation, the thermal comfort can be improved from Grade II to Grade I.

scholarly journals Experimental Study on Indoor Thermal Stratification in Large Space by under Floor Air Distribution System (UFAD) in Summer

Engineering ◽  
2011 ◽  
Vol 03 (04) ◽  
pp. 384-388 ◽  
Author(s):  
Xin Wang ◽  
Chen Huang ◽  
Weiwu Cao ◽  
Xuelei Gao ◽  
Wen Liu
Keyword(s):  
Experimental Study ◽  
Distribution System ◽  
Thermal Stratification ◽  
Air Distribution ◽  
Large Space

scholarly journals Fill ventilation of heated corn grain

2020 ◽  
pp. 74-77
Author(s):  
Mikhail Gennadievich Zagoruyko ◽  
Sergey Anatolyevich Pavlov
Keyword(s):  
Experimental Data ◽  
Distribution System ◽  
Air Flow ◽  
Air Distribution ◽  
The Dead ◽  
Over Time ◽  
Corn Grain

The grain masses of the first and subsequent batches, the equivalent coefficient of the dead gap of the air distribution system are calculated, the expressions for calculating the air flow for these batches and the experimental data on the change in moisture and temperature of the grain over time are given.

Sign in / Sign up

Export Citation Format

Share Document