Suction Gas Research Articles

Material Selection of Water-Ring Vacuum Pump in Yellow Phosphorus Tail Gas Industry

Material selection of water-ring vacuum pumps in the chemical industry is closely related to the suction gas medium composition. Using the case of 70,000 tons of sodium yellow phosphorus tail gas system of water-ring vacuum pump in Guizhou Kaiyang Qingli tianmeng Chemical Ltd. (hereafter abbreviation as Tianmeng Company), this paper introduces vacuum pump in the production process of yellow phosphorus tail gas, according to the characteristics of corrosion in acidic media on flow passage component, and analyze the factors influencing the selection of materials from the point of view of the production process of yellow phosphorus tail gas.

Temperature stratification under suction of the boundary layer from a supersonic flow

A carried out numerical simulation showed that a considerable difference can be achieved between the temperatures of a gas in the boundary layer and a suctioned gas under the gas suction from a turbulent boundary layer in a supersonic flow on a permeable surface. The effect of the Prandtl and Mach numbers of the incident flux on the temperature stratification, which depends on the gas suction intensity, is studied. The stratification is the most pronounced for low-Prandtl-number gases. It was established that, due to laminarization of the boundary layer under an intense gas suction, in the region of the impermeable plate following the permeable wall, the wall temperature drops abruptly.

Enhanced coefficient of performance by effective suction line cooling- an experimental report

The present paper is concerned with theoretical and experimental study and development of effective suction gas heat exchanger for hermetically sealed compressor. A single tube counter flow heat exchanger had been used, where water itself had been taken as a coolant. Energy consumption parameters as well as COP values have been obtained analytically for both the cases. Energy consumption parameter is 12% less as an average for a heat exchanger attached system compared to the system with out heat exchanger in a time span of 90 minutes. COP values obtained with heat exchanger are firmly better than that of the values with out Heat exchanger. COP values observed to be 7% higher for a heat exchanger coupled system compared to the system with out heat exchanger in the same time span of 90 minutes. In the present scenario where systems optimization is a necessity the present work would be useful in developing a energy efficient system with few modifications. This work would be useful to tackle the heat transfer related issues present in many gas compressors used in pumping and process industries.

Stability and three-wave interaction of disturbances in supersonic boundary layer with mass exchange on the wall

The interaction of disturbances in a boundary layer of the compressible gas is considered in the linear and nonlinear approximation (the weakly nonlinear theory of stability) in the presence of mass exchange (gas blowing or suction) on the surface. The regimes of moderate (the Mach number M = 2) and high (M = 5.35) supersonic velocities of the flow are considered. The suction from the surface is shown to lead to a considerable variation of the linear evolution of disturbances: the vortex disturbances of the first mode and the acoustic disturbances of the second mode are stabilized, the rate of variation is determined by suction intensity. The nonlinear interactions in three-wave systems between the vortex waves in asymmetric triplets at M = 2 and between the waves of different nature (acoustic and vortex waves) — in the symmetric ones at M = 5.35 are considered. The planar acoustic wave is the excitation wave in the latter, which excites the three-dimensional subharmonic components of the vortex nature. It is shown that one can delay considerably the transition region with the aid of suction, thereby one can reduce the skin-friction drag. In the gas blowing regime, strong deformations of the mean fields of boundary layers occur, which lead to the destabilization of the vortex and acoustic waves in the linear region and activate the nonlinear processes in transition region. One can expect that this will lead to the acceleration of tripping in supersonic flow.

Thermal and XRD analysis of synthesis of fluoro-topaz

The present work deals with thermal and XRD analysis of fluoro-topaz synthesis by sintering of aluminium and silicon oxides (in the form of corundum and quartz) with ammonium fluoride and carried out in open Pt crucibles (for XRD studies) and a closed furnace of simultaneous DTA/TG thermoanalytical apparatus called MOM Derivatograph. The furnaces are connected to a gas suction device to remove gas decomposition products.The study shows the endothermic peak at 125–155°C, representing the formation of ammonium aluminium hexafluoride and cryptohalite. The endothermic peak at 220–240°C represents the beginning of dissociation of ammonium aluminium hexafluoride to the more stable ammonium aluminium tetrafluoride. The endothermic peak at 340–350°C represents the dissociation of cryptohalite and ammonium aluminium tetrafluoride with the formation of aluminium fluoride.The formation of fluoro-topaz is represented by the wide endothermic peak at 770–800°C. The medium wide or sharp endothermic peaks at 950°C and 1000°C represent the subsequent dissociation of fluoro-topaz to corundum or mullite, respectively.

Comparison of Multiphase Pumping Technologies for Subsea and Downhole Applications

Summary The selection criteria for multiphase boosting options remain somewhat subjective and are frequently influenced by the vendors? data, which may mask potential limitations of this emerging technology. Existing literature on multiphase pumping tends to focus on a certain pump type for a specific field application, but does not provide more-generalized criteria for the selection of multiphase boosting solutions from among those available in the market. A comprehensive literature review into the working principles of the major pump types identified the intrinsic advantages and limitations of each technology for subsea and downhole applications. The survey showed that, for subsea application, both the twin-screw pump (TSP) and the helicoaxial pump (HAP) can handle high suction gas volume fraction (GVF) with a fluid recycling system, or flow mixer. Thus, GVF is not a discriminating factor. The positive-displacement principle allows TSPs to work with very low suction pressure, but limits their operating range because of the dependency of flow rate on their relatively low speed. However, these pumps can handle highly viscous fluid. The rotodynamic concept enables the differential pressure of HAPs to self-adjust to any instantaneous change in suction GVF, and to achieve higher flow rate if sufficient suction pressure is maintained. Because HAPs usually run at higher speed, they offer a wider operating range. For subsea application, HAPs appear to be a better option than TSPs because they offer higher operation flexibility and have a better installation track record. For downhole applications, the electrical submersible pump (ESP) and the progressing-cavity pump (PCP) are the outstanding favorites, with the latter being preferred for lifting streams that are viscous or with high sand content. For GVF up to 70%, the rotodynamic pump (RDP) is becoming a popular solution. Although it is claimed that the downhole TSP (DTSP) can handle up to 98% GVF, it is not yet widely accepted in the field.

Injection/suction effect on energy separation of compressible flows

New effects accompanying energy separation on a permeable surface are revealed in numerically modeling turbulent boundary layer flows. It is shown, in particular, that stratification is considerably higher in the case of gas suction from a supersonic flow than in the case of injection. This effect is most clearly expressed for low-Prandtl-number gases.

Modulation method of scroll compressor based on suction gas bypass

The air conditioners and heat pumps tend to work in much mild environments and part load situations rather than provide the rated full capacity under severe rated testing conditions. Both the capacity and inner compression ratio of the compressor should be regulated according to the working condition for higher energy efficiency and occupants’ comfort. A potential modulating technology of the scroll compressor, suction gas bypass, is investigated in this paper. The principle and operation method are illuminated and the adaptability is validated by experiments and simulations. As a conclusion, an appropriate suction gas bypass can reduce the inner compression loss of the scroll compressor under over compression conditions, enhance the system COP and also largely decrease the heating/cooling capacity of the refrigeration/heat pump system. ► Suction gas bypass (SGB) is an effective regulating method of scroll compressor. ► SGB reduces the inner compression loss under over compression conditions. ► SGB largely decreases the heating/cooling capacity of the refrigeration system.

CO2트윈 로타리 압축기의 흡입관로에서의 가스맥동 해석

ABSTRACT:For a CO 2 one-stage twin rotary compressor, a T-shaped suction port was used to effectively supply the suction gas stream into two individual suction chambers of the twin cylinders. Suction gas pulsations were observed in the pressure sensor signals and these were simulated by using the acoustic modeling of Helmholz resonators in parallel. The module of acoustic modeling was combined to a computer simulation program for the compressor performance. Validation of the simulation program has been carried out for a bench model compressor in a compressor calorimeter. Cooling capacity and the compressor input power were reasonably well compared between the simulation and the calorimeter test. Particularly, good agreement on P-V diagram between the simulation and the test was obtained.Keywords:Rotary compressor(로타리 압축기), Cooling capacity(냉방능력), Compressor work (압축기일), Gas pulsation(가스 맥동) †Corresponding author Tel.: +82-32-770-8419; fax: +82-32-770-8423 E-mail address: kimhj@incheon.ac.kr

Study on Characteristics of the Linear Air-Conditioner Compressor at Varied Operating Conditions

This paper mainly introduces a novel linear air conditioner compressor which is driven by the linear oscillatory motor with two divided moving body, of which the Cylinder-piston assembly presents symmetrical distribution along the axial direction. The compressor dynamics equations were built and solved numerically with the fourth order Runge-Kutta method. in the meantime, this paper emphatically analyzes the influence of those factors, such as the intake pressure, the exhaust pressure, the suction gas superheat, the cooling degree, on the compressor performance at varied operating conditions. These works shows that improving the suction gas pressure and reducing the exhuast pressure can help to increase the refrigeration capacity and energy efficiency ratio of the air conditioner compressor. Those analysis results provide theory foundation for design,development, and engineering application of this linear air-conditioner compressor.

Research on a New Composite Sealing Material of Gas Drainage Borehole and Its Sealing Performance

Aiming at the shortcomings of the traditional sealing materials of borehole for gas suction such as yellow mud and cement-sand grout, which indicated that the traditional sealing materials of borehole are easy to shrink after sealing, the sealing length of borehole is short and the sealing quality is not satisfactory, and the sealing price of the high- water material and polyurethane are also high. In this study, taking cement as a base material, a new composite sealing material mixed by expansion admixture, additive, fibrin and coupling agent was developed and the sealing performance and expansion performance of the material were also studied and analyzed. At the same time, the microscopic image handling system was used to investigate the microcosmic structure of material. The studying results showed that the new composite sealing material possessed a good expansion performance and a definite fluidity convenient for grouting. The material after solidification could combine closely with the borehole wall, and there was certain strength and it was not easy to shrink. Additionally, the suction gas concentration by borehole sealing exceeded 40%. It can be seen that the sealing performance of the composite sealing material is advantageous.

Surgical smoke management for minimally invasive (micro)endoscopy: an experimental study

The aim of this study was to investigate the use of surgical smoke-producing procedures such as laser ablation or electrosurgery in minimally invasive microendoscopic procedures. This study proposes a technical solution to efficiently remove surgical smoke from very small endoscopic cavities using microports as small as 20 G (0.9 mm) in diameter. The experimental laboratory study used small, rigid, transparent plastic cavity models connected with tubes and pressure sensors to establish an endoscopic in vitro laboratory model. A Kalium-Titanyl-Phosphate (KTP) laser with a 0.5-mm fiber optic probe was used to produce smoke from bovine scleral tissue in the cavity. Endoscopic gas insufflation into the model was generated by pressurized air and a microvalve. A laboratory vacuum pump provided smoke and gas suction via a microvalve. A self-built control and steering system was utilized to control intracavital pressure during experimental insufflation and suction. Problems related to smoke-generating processes, such as laser vaporization or electrocautery, in small closed cavities were first analyzed. A theoretical and mechatronic laboratory model was established and tested. Intracavital pressure and gas flow were measured first without and then with smoke generation. A new construction design for the suction tube was proposed due to rapid obstruction by smoke particles. Surgical smoke evacuation from endoscopic cavities that are as small as 2 cm in diameter via minimally invasive ports as small as 20 G (0.9 mm) in diameter may be safe and efficient if sufficient gas exchange is provided during smoke generation by laser or electrosurgical instruments. However, maintaining a low and constant pressure in the cavity during gas exchange and adopting a special construction design for the suction tube are essential to provide an excellent view during the surgical maneuver and to minimize potential toxic side effects of the smoke.

Hydrodynamic characteristics of a horizontal flow ejector in a rectangular chamber

The effects of the volumetric flow rate of primary motive water, water height, and the geometric parameters of the hydrodynamiccharacteristics of the gas suction rate and gas phase holdup were investigated in a rectangular chamber (0.22×0.26×1.2 m-high) with a horizontal flow ejector. Gas suction rate increased with increasing volumetric flow rate of the primary motive water, mixing tube length and diffuser length, but it decreased with increasing water height and nozzle diameter. The gas phase holdup was directly proportional to gas suction rate, indicating its corresponding increase with the volumetric flow rate of the primary motive water. Conversely, it decreased with increasing water height and nozzle diameter. However, the mixing tube length affected the gas phase holdup minimally compared to other operating parameters. Both the gas suction rate and gas phase holdup correlated with the dimensionless equations of operating parameters.

205 動態保存されている定置式木炭ガス機関 : 小林式ガス発生機と吸入ガス発動機(OS機械技術史・工学史(I))

205 動態保存されている定置式木炭ガス機関 : 小林式ガス発生機と吸入ガス発動機(OS機械技術史・工学史(I))

Investigation of potential benefits of compressor cooling

The compressor is certainly the largest power consumer in a vapor compression system. To reduce the power consumption of the compressors two performance improving options are investigated theoretically for refrigerants R22, R134a, R410A and R744 as working fluids. The first option is cooling the motor by external means other than using the suction gas. Analysis results for this option show that R22, R410A and R744 have larger potential benefits than R134a. In low temperature refrigeration applications larger improvements are achievable than in air conditioning applications for all four refrigerants. The second option is to make the compression process isothermal by transferring heat from the compression chamber. To approach the isothermal compression process while avoiding wet compression, two cases of combining isothermal and isentropic compression processes are analyzed. The analysis results show that this strategy can reduce the compression work up to 14% as compared to the isentropic compression process for the R22 refrigeration system at ASHRAE T condition. The second analysis on the ideal vapor compression cycles using such compressor cooling strategy show that the compression power of the system can be reduced by up to about 16% depending on operating conditions and fluid choice.

Numerical and experimental investigations of gas–liquid dispersion in an ejector

The effects of the ejector geometry (nozzle diameter and mixing chamber) and the operating conditions (liquid circulating rate, liquid level in column) on the hydraulic characteristics in a rectangular bubble column ( 0.22 × 0.26 × 1.3 m 3 ) with a horizontal flow ejector were determined. The gas phase holdup increases with increasing liquid circulating rate but decreases with increasing liquid level in the column. In the multiphase CFD simulation with the mixture model and the experiments, the gas suction rate increases with increasing liquid circulating rate. However, the gas suction rate decreases with increasing the liquid level in the column and nozzle diameter. The predicted values from the CFD simulation are well accord to the experimental data.

Numerical and experimental investigation of burner device for anode gas reburning

A complex numerical and experimental investigation of burner devices for a reburning of the anode gas of aluminum production was carried out. The chosen mathematical model of the processes of aerodynamics, heat exchange, and gas burning was identified and adapted on the basis of data of real-scale measurements. Basing on computational experiments the optimization of the design of elements of the system for anode gas detoxication and transport was carried out. A new system was proposed and tested for reburning the anode gases of electrolysis production, which consists of an improved burner device and a dust-sedimenting chamber with a possibility of regulating the amount of gas suction.

Development of a double acting free piston expander for power recovery in transcritical CO 2 cycle

To replace the throttling valve with an expander is considered as an efficient method to improve the performance of the transcritical CO 2 refrigeration cycle. This paper presents the design and experimental validation of a double acting free piston expander, in which a slider-based inlet/outlet control scheme is used to realize a full expansion process for the expander. The power extracted from the expansion process is utilized by an auxiliary compressor, which is arranged in parallel with the main compressor. A design model is developed to determine the geometric parameters of the expander together with the auxiliary compressor. An expander prototype is manufactured and validated experimentally in the air test system, mainly by means of analyzing the dynamic pressures in the expander chamber. The experimental results show that the expander can work stably in a wide range of pressure differences/ratios at the frequency approximately linear with the pressure difference through the expander. The p– t diagrams in the expander indicate that the slider-based inlet/outlet control scheme enables the expander to have the proper suction, expansion and discharge processes. However, the prototype at high frequency doesn’t present isobaric suction process, which results in insufficient gas suction and therefore decrease in the expander efficiency. With the p– t diagrams at various frequencies compared, the optimal working frequency is found to range from 10 to 17 Hz in the air system. The isentropic efficiency of 62% is obtained from the p– V diagram analysis. Further validation of the expander in the CO 2 system will be conducted in the near future.

Dynamics of furnace processes in a CFB boiler

With the aim of understanding the dynamics of combustion, this work examines simultaneous fluctuations in fluid dynamic parameters and gas composition measured in a CFB furnace operated with coal as a fuel. The fluid dynamic parameters investigated are pressure and air flow entering the furnace. Gas composition was recorded by a zirconia-cell probe and a gas suction probe connected to a mass spectrometer having a high time resolution (10 Hz). The principal fluctuations detected are around 1 Hz and below 0.3 Hz. The fluctuations below 0.3 Hz mostly originate from variations in the fuel-feed rate. These variations create periods of reducing conditions caused by a momentarily high fuel input accompanied by a pressure rise in the furnace and a reduction of the air feed, which occurs concurrent with the release of an enhanced quantity of volatiles. Modelled pressure fluctuations based on the relation between volatile release and pressure in the furnace give similar pressure fluctuations as the measured pressure fluctuations, with respect to amplitude and characteristic time scale of the fluctuations. There is also a correlation between reducing conditions and the concentration of hydrocarbons.

Power Saving of Large-Scaled Helium Compressor for Fusion Device

For the purpose of reducing the power consumption of a cryogenic system for an experimental nuclear fusion system, investigation of the relationship between the ambient temperature and the mass flow rate of the compressor was carried out. When the suction gas temperature is lowered, gas density increases. The mass flow rate of the compressor can therefore be increased without any change in power consumption. It has been confirmed that some 5.6% of compressor power consumption can be saved by making the cooling water temperature equal to the ambient temperature during the winter season with the continuous running of the cooling tower fan motor. Further, a new gas compression cycle using an additional auxiliary gas cooling system was developed to lower the compressor suction gas temperature. Compared to a conventional system, some 11% of power consumption can be saved using this new gas compression cycle when the helium gas suction temperature of the compressor is 235K.