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Flow of Fluids
Published in Siddhartha Mukherjee, Process Engineering and Plant Design, 2021
A reciprocating pump is a positive displacement machine consisting of one or more cylinders, each containing a piston or plunger driven by slider-crank mechanisms and a crankshaft from an external source. The pump capacity is determined by the rotational speed of the crankshaft. In the third type of reciprocating pump, the driving member is a flexible diaphragm fabricated of metal, rubber or plastic [5].
Overview of the Fermentation Industry
Published in Debabrata Das, Soumya Pandit, Industrial Biotechnology, 2021
Positive displacement pumps (PDP) use a backward and forward movement to move a fluid. They comprise a piston, plunger, and diaphragm. The advantage of a diaphragm is that liquid being transferred is not in direct contact with the pump due to the presence of a membrane. The reciprocating pump is one in which the liquid follows the movement of a piston during suction and delivery strokes. Here a moving fluid is captured in a cavity which then discharges that fixed amount of fluid. Some of these pumps have an expanding cavity at the suction side and a decreasing cavity at the discharge side. In these pumps no fluid comes back to its casing during pumping out. Examples are progressive cavity pumps, peristaltic pumps, gear pumps, screw pumps, rotary gear pumps, lobe pumps etc. In these pumps pressure is applied directly to the liquid by a reciprocating piston or by rotating members. They are used for shear-sensitive liquid, high-pressure application and variable viscosity applications. Types include reciprocating and rotary pumps.
Pump Class Selection
Published in J. T. McGuire, Pumps for Chemical Processing, 2020
Rotary pumps inherently have close running clearances, see Chapter 7. As liquid viscosity decreases, pump performance falls off and, if the liquid has low lubricity, clearance life can also deteriorate. When the pumped liquid has low viscosity (or low lubricity) and the pump differential pressure is high, a reciprocating pump is the more appropriate selection. As a guide, pumps for liquids whose viscosity is below 100 SSU warrant investigation.
Swell-shrink behaviour of an expansive soil stabilised by CCR-fly ash (FA) columns and CCR-FA blends
Published in Geomechanics and Geoengineering, 2022
Farahnaz Darikandeh, B. R. Phanikumar
In swell-shrink tests, the soil specimens were initially inundated with water and allowed free swell and then, after equilibrium swell, were dried to its initial height at ordinary conditions, and then inundated again to continue the swell-shrink cycle. After seven days of swelling, water was removed from the specimens using a medical syringe without dismantling the oedometer cell in order to simulate the field condition. For this, a 10 ml medical syringe consisting of a plunger and barrel was used. Then, the flexible small-bore transparent tube was connected to it. The transparent tube was put into the oedometer cell. By pulling the plunger along the inside of the tube, the syringe was allowed to take in the water from the cell and discharge it. Here, the syringe simply acts as a manual reciprocating pump.
Glasshouse-enclosed parabolic trough for direct steam generation for solar thermal-enhanced oil recovery (EOR) – energy performance assessment
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Ramesh Vakkethummel Kundalamcheery, Venkateswarlu Chintala
In GPTC installation, the parabolic troughs and accessories were installed inside a glasshouse structure as shown in Figure 1. The glass enclosure will seal against dust, rain and wind, and ease humidity control of air inside the glasshouse. Parabolic reflectors were made of lightweight structures, and mirror surface is a polished aluminum film, which helps to increase the life of GPTC plant. A tracking mechanism was designed to follow the sun and support concentrating sunlight onto steam generator receiver tubes all the time, while the facility is in operation. The receiver tube was designed as a once-through steam generator (OTSG). A reciprocating pump was used to deliver high-pressure feedwater, from one side of the evaporator receiver tube and from another side, high-pressure steam is being delivered to the steam header or steam injection wells as applicable. Each glasshouse enclosure contains a fixed number of rows of solar collectors and receiver tube assembly of definite length. Working principle and schematic of the steam injection process using glasshouse-enclosed trough PTC integrated with a fired OTSG is represented in Figure 1(a-b) and the photograph of actual installation is in Figure 1(c).
Novel multistage solid–liquid circulating fluidized bed: liquid phase mixing characteristics
Published in Particulate Science and Technology, 2020
Manjusha A. Thombare, Dinesh V. Kalaga, Sandip B. Bankar, Rahul K. Kulkarni, Satchidanand R. Satpute, Prakash V. Chavan
An acrylic column with an inner diameter of 100 mm and height of 1.20 m was used. A reciprocating pump of 250 mL.s−1 capacity was used to feed water to the column. To smoothen the liquid flow, a pulsation dampener was fitted to the pump. The dampener pressurizes the liquid when the pump is at full flow and discharges to the system when the pump outflow falls. This significantly smoothes the flow such that the outflow is practically uniform. The water flow rate was measured using rotameter. A calming section packed with glass beads of 0.30 m height was provided to homogenize the liquid flow before it reaches to the liquid distributor. The distributor was a perforated plate containing 315 holes of 2 mm diameter on a triangular pitch, giving a free area ratio of 12.50%. A mesh of BSS 100 was attached on top and bottom of the distributor plate to restrict the movement of particles across it. To ensure that no air bubbles intruded into the column during operation, the necessary arrangements in the fittings and fixtures were made. A septum was provided at the bottom of the column below the liquid distributor for injecting predetermined amount of the tracer using a syringe (having 2 mm needle). The provisions were made for online measurement of tracer concentration using conductivity meter. The concentration of tracer was measured in terms of voltage with online data acquisition system at a frequency of 10 Hz using a graphite electrode (probe), fixed at the bed surface.