Rotary Pump Research Articles

СОВЕРШЕНСТОВАНИЕ КОНСТРУКЦИИ МУФТЫ УПРУГОЙ ВТУЛОЧНО-ПАЛЬЦЕВОЙ

The investigation purpose is life increase of clutch couplings in rotary pump units by means of designing an advanced clutch coupling. 
 For that there were defined the reasons of failure and short life of an elastic sleeve-pin clutch for joining a rotary pump and electromotor. As a result of industrial tests of a rotary pump unit there were revealed the following factors decreasing life and hence equipment reliability: a wrong alignment with the pump; half-coupling imbalance (pin wear, non-coaxiality (misalignment) of holes for pins or half-coupling misalignment); bearing unit gaps (bearing defects); pump and electromotor rotor balancing; mounts and abutments of a frame base. 
 For elimination of drawbacks revealed there was developed an updated design of an elastic sleeve-pin clutch for the rotary pump of 200D90 type having no counterparts in Russia. During the investigation there were carried out industrial tests at PC “Samotlorneftegas”. Due to the updated design offered the clutch ensures life increase and a more reliable working capacity in the course of operation.

Study on Speed and Clearance Optimization of All-Metal Progressing Cavity Pumps: Experiment and Simulation.

The stator and rotor of an all-metal screw pump are made of metal; so the matching method of the all-metal screw pump cannot be like that of the traditional rubber screw pump, and a certain gap must be reserved. If the gap is too small, it will affect the normal operation of the pump. If the gap is too large, the pump leakage will also become larger, affecting the efficiency of the pump. In this paper, the method of numerical simulation is used to optimize the gap of the pump. At the same time, it is found that the optimal gap of the pump is closely related to the viscosity of the fluid transported by the pump, and different viscosity fluids have different optimal speeds. The speed and clearance of the pump are optimized through numerical simulation to ensure high pump efficiency while taking into account energy saving and avoid the waste caused by excessively high speed. Finally, the relevant research results of numerical simulation are verified through experiments, and it is found that the experimental results are in good agreement with the simulation results, which also proves the accuracy of the numerical simulation results.

Analysis of the efficiency of an automotive alternator by replacing Mild steel into aluminum as a material for rotor

In real time automotive electrical systems, an alternator is usually used for charging the vehicle. The alternator generates AC voltage which is converted into DC voltage through rectifier of an alternator and this DC voltage helps to charging the vehicle’s battery. The alternator further coupled with the vacuum pump, provides vacuum to the suction line of the vehicle’s braking system. The rotor of the vacuum pump is made of mild steel which weighs high. Hence, it may act as a load to the alternator and reduces its efficiency. In the proposed model, efficiency and performance characteristics of the alternator are improved by reducing the mass of the rotor. Here, the mild steel is replaced by aluminum metal which weighs less. By using this, the mass of the vacuum pump is reduced, due to which the output power of the alternator gets increased. This increase in output power improves the efficiency of an alternator and subsequently the performance of the vehicle’s charging system is improved.

Development and characterization of a volume flow measurement system for low-pressure gases

This paper presents the design and validation of a volume flow measurement system developed to measure volume flowrate of gas at pressures below 1 kPa. The system had to be developed because a suitable commercial transducer was not available for the unusual working environment, where outgassing and sublimation phenomena become relevant for many materials and the rarefied atmosphere changes dramatically its heat and mass exchange parameters. The development of a low-pressure compatible measurement system comes from the need of measuring the flow rate of a rotary vane pump working under an environmental absolute pressure in the range between 600 and 1000 Pa, mostly composed by CO2 i.e. the average condition of the Martian atmosphere at the surface. The pump will be a key component of the MicroMED particle analyzer, an instrument of the ExoMars 2020 ESA-Roscosmos mission payload. The measurement system is based on a control volume, made by a stainless-steel bellow, which has been designed accounting for the environmental requirements and the expected flow rate. The measurement system has been calibrated at ambient condition and tests in low-pressure have been performed to validate the measurement system and to derive the flow rate characteristics of a pump mock-up at different environmental pressures.

Efficacy of Securidaca longipedunculata Fresen (Polygalaceae) against Two Standard Isolates of Neisseria gonorrhoeae

Aim: A study was carried out to determine the in vitro antibacterial activity of ethanol extract of root and bark of Securidaca longipedunculata against two standard isolates of Neisseria gonorrhoeae NO.0296 and WHO- K.
 Materials and Methods: Plant materials were collected and dried at room temperature, followed by ethanol extraction using a rotary pump. Antibacterial activity was done on the isolates using agar disc-diffusion method with Dimethyl Sulfoxide (DMSO) as a negative control and ceftriaxone as a positive control. Zone of inhibition was measured in millimeters. Minimum bactericidal concentration of the extract was determined using different concentrations of the extract then plated on Neisseria gonorrhoeae (GC) medium and a standard protocol was used to determine the presence of phytochemical compounds.
 Results and Discussion: The results obtained showed that both the root and bark extracts of S. longipedunculata have antibacterial activity against the two bacterial strains with a zone of inhibition of ≥ 10mm and a bactericidal activity at 0.01µg-ml of 10% crude extract. Comparison of susceptibility on tetracycline, penicillin and ciprofloxacin with the root and bark extract showed higher susceptibility to the extracts. The extracts showed presence of saponins, steroids, glycosides, flavonoids, terpenes, alkanoids, phenolics and tanins. The demonstrated antibacterial activity of S. longipedunculata against N. gonorrhoeae provides a scientific basis for the traditional use in treating venereal diseases in western Kenya.
 Conclusion: This investigation and further studies will pave the way for use of this plant in antibacterial drug development for alleviating human suffering. We recommend further studies to identify the specific compound(s) responsible for the antibacterial activity.

Automatic resonance tuning mechanism for ultra-wide bandwidth mechanical energy harvesting

Piezoelectric energy harvesters typically exhibit sharp peak in output power around resonance frequency (small bandwidth), which presents complexity in harvesting ambient vibrations that normally comprise of multiple frequencies. Prior attempts in designing energy harvesters with broadband response have met with practical challenges in terms of low output power, large mass and weight, and small improvements in bandwidth. Here, we report a breakthrough in demonstrating ultra-wide bandwidth piezoelectric energy harvesters through the automatic resonance tuning (ART) phenomenon. ART provides energy harvester ability to adjust its natural frequency in conjunction with ambient vibration without human intervention or additional tuning energy. The ART energy harvester utilizes the motion of the mobile proof mass in a doubly clamped oscillating beam structure to modulate the natural frequency of the beam. Detailed investigations are conducted in providing a fundamental understanding of the operation mechanism of the ART harvester by invoking beam dynamics over a wide range of vibration conditions. It is shown that bandwidth of the ART harvester (36 Hz) is 1400% larger compared to the fixed resonance energy harvester. The practical feasibility of the ART mechanism is demonstrated by evaluating the performance of the harvester mounted on a rotary pump. The results demonstrate that ART mechanism can provide the much-needed breakthrough in the deployment of mechanical energy harvesters for naturally occurring vibrations. • Ultra-wide bandwidth piezoelectric energy harvester is demonstrated through the automatic resonance tuning (ART) phenomenon. • A fundamental understanding of the operation mechanism of the ART harvester is provided by invoking beam dynamics over a wide range of vibration conditions. • The bandwidth of the ART harvester (36 Hz) is 1400% larger compared to the fixed resonance energy harvester. • The practical feasibility is demonstrated by evaluating the performance of the ART energy harvester mounted on a rotary pump.

Investigation of the Internal Displacement Chamber Pressure of a Rotary Vane Pump

Low noise emissions of vehicle components are today a quality feature in the automotive sector. In automatic transmissions in particular, the hydraulic pump often contributes significantly to noise, which motivates research to clarify the noise sources and transmission pathways in these components. The subject of the present investigation is the generation of noise by the inherently instationary flow in hydraulic pumps. In order to shed some light on these phenomena, a computational fluid dynamics (CFD) simulation model for flow investigations on rotary vane pumps was set up. In this work, first the influence of different simulation parameters on the numerical results is analyzed. Then the pressure in the internal displacement chambers of the pump is examined, as it can be assumed that this is the essential parameter for noise generation. Different operating conditions such as rotational speeds and delivery pressures are investigated. Furthermore, the simulation results are compared to pressure measurements for validation and are used to find optimization potentials.

Charging Characteristics of Series Connected Insulation and No-Insulation HTS Coils by Rotary HTS Flux Pump

High-temperature superconducting (HTS) coil wounds without turn-to-turn insulation (NI coils) present excellent electrical and thermal performance compared to HTS coil wounds with Kapton tape (INS coils). However, NI HTS coils are physically connected to power supplies at room temperature, resulting in increased operating costs due to complex cooling systems and constant heat loads. To overcome this issue, recent studies have investigated alternative charging methods such as flux pump, a power source without any physical contact with the HTS coil at cryogenic temperatures. Even though the NI coil is charged using a flux pump, the disadvantageously slow charge and discharge time remain. In this study, we conducted experiments to compare the charging characteristics of INS and NI coils using a rotary HTS flux pump. A superconducting circuit comprising two coils with equal inductance magnitude is connected in series. From the experiments, we compare the charging characteristics of charging time constant and magnetic field when the same current is applied to the two coils with a power supply and a rotary HTS flux pump. In the NI coil rotary HTS flux pump case, the charging time constant converged to about 6 s in the alternating magnetic field (AMF) above 20 Hz, and the value is similar to the power supply. At 60 Hz and higher AMF, the maximum magnetic field difference from the power supply converged to less than 1%, which appears to be a difference in current and voltage source.

Analysis of Leakage Model of All-Metal Screw Pump

Traditional rubber screw pumps use an interference method to engage. When the pressure is less than the breakdown pressure of the pump, there is no leakage in the pump. The all-metal screw pump stator and rotor are made of metal, and the stator and rotor adopt a gap-fitting engagement method, so even when the pump is working normally, the leakage is objective. Based on the concentric annular gap flow, the pressure drop leakage caused by the fluid inertia force is fully considered, and the calculation formula of the leakage of the all-metal screw pump is studied from the three aspects of transverse leakage, longitudinal leakage, and oblique leakage. This model was experimentally verified by a commercial all-metal screw pump produced by Shihong Petroleum Equipment Company. The model results show that the leakage of the all-metal screw pump is mainly affected by the structure parameters of the pump itself and the density of the pumped fluid, and the gap height is the main factor affecting the leakage.

Development of Damping Support for a Turbine Pump Assembly of a Cryogenic Fuel Aviation Gas Turbine Engine

Theoretical studies and design studies have been conducted to demonstrate the possibility of using a long hydrodynamic damper in the supports of a hydrogen pump rotor was shown. The complex problem of rotor dynamics and design synthesis of a hydrodynamic damper for a turbopump assembly (TPA) was solved. The geometric parameters of the hydrodynamic damper are determined that ensure the necessary damping level, d = 3 × 103 N s/m. It is shown that at such a damping level, the amplitude of rotor oscillations does not exceed the value of clearances in supports and on blade shoulders.

Effects of blood pump orientation on performance: In vitro assessment of universal advanced ventricular assist device.

An advanced ventricular assist device (VAD), which is under development in our institution, has specific features that allow changes in the axial rotor position and pump performance by intrapump pressure difference. However, performance could be influenced by the pump orientation because of the effect of gravity on the rotor position. The purpose of this study was to evaluate the effects of pump orientation on the pump performance, including pulse pressure and regurgitant flow through the pump when the pump was stopped. Bench testing of the VAD was performed on a static or pulsatile mock loop with a pneumatic device to simulate the native ventricle. The pump performance, including pressure-flow curve, pulsatility, and regurgitant flow, was evaluated at several angles, ranging from -90° (inlet pointed upward) to +90° (inlet pointed downward) at pump speeds of 2000, 2500, 3000, and 3500 rpm. The pump performance was slightly lower at +90° at all rotational speeds, compared with -90°. The pulse pressure on the pulsatile mock loop (80 bpm) was 50 mmHg without pump support, remained at 50 mmHg during pump support, and was not changed by orientation (-90°, 0°, and +90°). When the pump was stopped, the regurgitant flow was near 0 L/min at all angles. Pump orientation had a minor effect on pump performance, with no effect on pulse pressure or regurgitant flow when the pump was stopped. This indicates that the effect of gravity on the rotor assembly is insignificant.

Effects of Different Blade Numbers on Radial Exciting Force of Lobe Pump Rotor

Effects of Different Blade Numbers on Radial Exciting Force of Lobe Pump Rotor

Conceptual Considerations for Device-Based Therapy in Acute Decompensated Heart Failure: DRI2P2S.

Acute decompensated heart failure remains the most common cause of hospitalization in older adults, and studies of pharmacological therapies have yielded limited progress in improving outcomes for these patients. This has prompted the development of novel device-based interventions, classified mechanistically based on the way in which they intend to improve central hemodynamics, increase renal perfusion, remove salt and water from the body, and result in clinically meaningful degrees of decongestion. In this review, we provide an overview of the pathophysiology of acute decompensated heart failure, current management strategies, and failed pharmacological therapies. We provide an in depth description of seven investigational device classes designed to target one or more of the pathophysiologic derangements in acute decompensated heart failure, denoted by the acronym DRI2P2S. Dilators decrease central pressures by increasing venous capacitance through splanchnic nerve modulation. Removers remove excess fluid through peritoneal dialysis, aquaphoresis, or hemodialysis. Inotropes directly modulate the cardiac nerve plexus to enhance ventricular contractility. Interstitial devices enhance volume removal through lymphatic duct decompression. Pushers are novel descending aorta rotary pumps that directly increase renal artery pressure. Pullers reduce central venous pressures or renal venous pressures to increase renal perfusion. Selective intrarenal artery catheters facilitate direct delivery of short acting vasodilator therapy. We also discuss challenges posed in clinical trial design for these novel device-based strategies including optimal patient selection and appropriate end points to establish efficacy.

Experimental confirmation of the possibility of using a hydraulic diode in the discharge line of a spur rotary pump

The operation of a spur rotary pump with different elements (valve, hydraulic diode, long and short pipelines) in the discharge line is investigated. Keywords hydraulic machine, spur rotary pump, hydrodiode, indicator diagram. Sergey7-2005@mail.ru

Experimental confirmation of the possibility of using a hydraulic diode in the discharge line of a spur rotary pump

The possibility of using the method of invariant moments of images as a way of comparing the geometric shape of 3D models to search from a database of previously created models is considered. The found models can be used as a prototype for the development of a new part. Keywords 3D-model, contour, contour comparisons, Hu-moments. kdimka@list.ru

Numerical Study on Loss Mechanism in Rear Rotor of Contra-Rotating Axial Flow Pump

Numerical Study on Loss Mechanism in Rear Rotor of Contra-Rotating Axial Flow Pump

Design and development of pressurized aqueous fertilizer application system for seeder

In dry land areas, seed germination greatly affected by insufficient soil moisture during sowing. Nitrogenous fertilizers like granular urea remain unavailable due to inadequate soil moisture to dissolve, dilute and convey it to root zone level. Precise application of aqueous fertilizer at root zone depth at the time of sowing enhances seed germination percentage by increasing available soil moisture as per the soil-moisture-crop requirement. A pressurized aqua ferti metering system was designed and developed for application of aqueous fertilizer diluted with water along the side of seed. The prototype consisted of pressurized aqueous fertilizer metering system through positive displacement pump, stationary opening with agitator type seed metering system and shovel type furrow opener with provision of carrying seed and aqueous fertilizer delivery tubes. A pressurized aqueous fertilizer application system consisted of rotary gear pump to vary pump rotational speed and circular distributor for uniform distribution of aqueous fertilizer. The flow rate and pressure were controlled by control valve for required amount of aqueous fertilizer. Three nozzles of size 8, 10 and 12 mm were evaluated at different pump rotational speeds (1800, 1440, 1152, 1080 and 864 rpm) and different control valve positions (0, 2, 4 and 6 kg/cm2 ) for desired flow rate. The discharge rate at a particular pressure was found to vary linearly with the Pump rotational speed and decreased as the line pressure increased. The desired flow rate in pressurized pumping system was obtained in a nozzle of size 10 cm up to a maximum pump speed of 1440 rpm and for a line pressure of less than 4 kg/cm2 .

Total Artificial Heart Incorporating Novel Stacked Motor; First In Vivo Results

The latest version of the continuous flow total artificial heart (CFTAH), which incorporates a novel stacked motor to improve passive self-regulation of pressure difference between the left and right atria, and reduce pump rotor over-excursion, was tested in vivo in a calf model to assess operational performance. The CFTAH was implanted in a calf and run at various pump operating conditions including mean pump speeds from 2400 to 3600 RPM, sinusoidal speed modulations from 0 to 25%, and speed modulation rates from 80 to 120 B.M. It was also tested under various combinations of simulated high and low systemic vascular resistance and pulmonary vascular resistance via outlet graft clamping and administration of a Nitroprusside respectively. The CFTAH responded to all control inputs and ran as expected during the experiment. The head curves of the right and left pumps generated from measured pressures, measured right flow and calculated left flow, were consistent with in vitro data on this pump. The passive atrial pressure regulation performed well in the normal operating range, and there were no signs of excessive rotor axial displacement during extreme pressure excursions as had been seen in the previous versions of the pump. The left atrial pressure was unusually low throughout most of the experiment and we believe that this may have been due to partial blockage of the of the left inflow cuff proximal to the pressure line tap. This led to several left inlet suction conditions and extreme pressure conditions. The replacement of the standard, single stack stator motor with the new dual stator stack motor resulted in better passive regulation of the pressure difference between the left and right atria. Also, the extreme pressure conditions resulting from left inlet suction events did not cause the pump's rotor to rub against the volute housing as had been seen in previous versions of the pump. Even though the self-regulation was acceptable, shifting of the regulation characteristic to increase the nominal LAP-RAP value will improve the regulation further, and this modification will be implemented prior to the next in vivo experiment.

Dynamic model and numerical simulation for a new eccentric rotary multiphase pump

In order to simplify the manufacture of multiphase pump and improve the operating flexibility for gas void fraction (GVF) of the multiphase fluids that the pump transported, an eccentric rotary multiphase pump (ERMP) is presented. In this study, the structural characteristics and working principle of the ERMP are presented first. Then, the kinematic and force models are established for the key components- sliding vane and rotor. The velocity, acceleration, and force equations with shaft rotation angle are derived for each component. Based on the established models, simulations are performed for an ERMP prototype. The simulated results show that the areas opposite the sliding vane and apart from the center of the rotor have larger velocities and wear problem. Moreover, the binding force, pressure difference induced force and the normal force exercise a negative effect on the friction at the sliding vane sides and rotor. Lower shaft speed and smaller eccentric distance of the crankshaft are helpful to reduce this effect. The findings confirm that the proposed ERMP is suitable for multiphase transportation and has a higher mechanical efficiency for its advanced structure and working principle.

EFFECTS OF HEAD GAPS AND ROTOR GAP ON FLOW RATE AND HYDRAULIC LEAKAGE OF A NOVEL NON-CONTACT ROTOR BLOWER

The Roots blower belongs to the non-contact rotor pump family, therefore, there are always certain clearances between rotors and clearances between the rotor and the stator. These clearances have serious effects on the working performance of blower. Therefore, to determine the design error and the method of machining to achieve the lowest price, required machining technology, flow rate and pressure, the determination of leakage flow rate and pressure through the head gap and rotor gap is very necessary. Thus, in this paper, the authors conduct to build a mathematical model in order to determine the flow rate and pressure of blower in the ideal case in which there is no clearance and the case in which there are clearances. On that basis, the authors aim to evaluate the impact of head gaps and rotor gap on flow rate and pressure leakage. In order to improve the working performance of blower and to choose the machining method that is suitable for the applications of this blower.