An experimental rig has been built to test a horizontal scroll compressor and a reciprocating compressor of similar size and capacity. The compressors were tested with refrigerant.R404A operating at varying evaporator and condenser temperatures. The paper provides much needed information regarding the efficiency of the compressors operating under the same conditions with the same system paramet...

By researching the influence of micro-groove texture on surface tribological properties stator and rotor pair oil production hydraulic motors, this paper aims to reduce frictional resistance moment spiral further solve problem difficult restart pump a certain type hydraulic-driven screw pump. According metal-rubber flat plate reciprocating friction model is established, rectangular micro-groove...

Preliminary process design in 1997 for a new grass roots polymer unit in the Gulf Coast raised the possibility of using a single centrifugal pump instead of two reciprocating compressors to feed ethylene into the reactors. The objectives of this change were lower capital cost, energy consumption, and maintenance expense. Discussion of the possible application led finally to the design, manufact...

INTRODUCTION The introduction of nickel-titanium (NiTi) files into clinical practice has improved the quality of canal shaping, but increasing the curvature of the root canal (or the diameter of the master instrument that prepares the full working length) could result in more transportation, straightening, and aberration of the canal. Nickel-titanium instruments are significantly safer and have...

The main factors affecting utilization of volumetric displacement of reciprocating compressors are analysed. A coherent system of parameters to quantify these is formulated. Reference is made to conventional parameters and to the work of other authors. Some new parameters are introduced and int~rrelationships are described. The overall_purpose of the theory is to apportion shortcomings in the v...

introduction: the aim of this study was to compare the changes that occur in the danger zone (dz) after preparation of curved mesiobuccal (mb) canals of mandibular first molars with waveone instruments in two different movements [reciprocation (rcp) and counter-clockwise rotation (ccwr)] by means of cone-beam computed tomography (cbct). methods and materials: mb canals of 30 mandibular molars w...

This paper presents and examines a new design concept for bistable reciprocating piston pump. The pump mechanism belongs to the mechanisms, which have two stable positions at end of suction discharge strokes. transition between is achieved by using triggering force each beginning subsequent movement recuperative spring. In this mechanism, forces are created Shape Memory Alloy (SMA) wires. Geome...

Many software tools are used to simulate compressor performance and pressure pulsations in piping systems. Designers of reciprocating equipment rely on these tools to accurately simulate gas properties and pressure pulsations for specialty gases. Two case studies on reciprocating compressors, involving ethane and ethylene, outline the root causes and consequences of inaccurate performance and p...