China
Africa
Explore chapters and articles related to this topic
Design and Operation of Chemical Phosphorus Removal Facilities
Published in Richard Sedlak, Phosphorus and Nitrogen Removal from Municipal Wastewater, 2018
From required chemical dosages, metering pump capacities can be determined. If dosage volumes are small, diaphragm metering pumps or small progressing cavity pumps should be used. For very large dosages, centrifugal pumps or large progressing cavity pumps may be required. The practical maximum capacity of a diaphragm metering pump is approximately 500 gallons per hour. Pump redundancy or piping interconnection between pumps for similar service should be provided to assure continuous operation of critical processes in the event of pump failure. Pumps used in chemical phosphorus control include: horizontal end suction centrifugal, vertical wet pit centrifugal, progressing cavity, and diaphragm metering. A detailed description of materials of construction will be included in the section on facility design.
Pumps and Turbines
Published in Henry Liu, Pipeline Engineering, 2017
Metering pumps are PD pumps, usually of the piston, plunger, or diaphragm type. A metering pump contains equipment that can measure and adjust the speed and/or stroke length of the piston (plunger), in order to produce a predetermined discharge through the pump. It combines the function of a pump and the function of a flowmeter into a single piece of equipment. Metering pumps are also called proportioning pumps. They are used extensive in the chemical and food industries whenever a need exists to mix different chemicals or foods in liquid or slurry forms at desired proportions. They are more expensive than ordinary PD pumps, and hence should not be used unless metering is needed — i.e., unless one needs to mix different liquids or slurries at predetermined and controllable rates.
Positive Displacement Pumps
Published in Don Renner, Hands-On Water/Wastewater Equipment Maintenance, 2017
1.09 Other things to consider in the selection of a pump are its suction lift and discharge pressure capacities. (Note: suction and discharge heads are discussed in Volume 1, Chapter 12, paragraphs 12.04 to 12.14.) Because metering pumps are positive displacement style pumps, they can lift the fluid 15 or more feet without any problem. Also, they are capable of delivering the fluid at very high pressures, sometimes over 2,000 pounds per square inch (psi). Because the delivery pressure and the pump capacity do not always follow the same rules or pattern, it is very important to check the manufacturers literature before selecting a metering pump.
Flow accelerated corrosion of carbon steel containing chromium under water chemistry conditions of boiling water reactor applying mitigation techniques of corrosive environment
Published in Journal of Nuclear Science and Technology, 2022
Kazushige Ishida, Yoichi Wada, Takayuki Shimaoka, Ryosuke Shimizu
Corrosion testing was conducted using the high temperature and high pressure loop shown in Figure 1. Pure water was stored in a water tank and continuously passed through an ion exchange resin column using a circulation pump to maintain the electrical conductivity of pure water at 10 μS m−1 or less. Dissolved oxygen concentration was controlled to the test conditions by bubbling nitrogen and oxygen into pure water. The electrical conductivity was continuously measured with an electrical conductivity meter, and the dissolved oxygen was continuously measured with a dissolved oxygen meter. Water controlled to the test conditions (test water) was supplied using a high pressure metering pump. The water was heated as it passed through a heat exchanger and heater, before passing through the test section. Pressure was adjusted by the pressure regulator. The flow rate was measured with a flow meter downstream from the pressure regulator. The test water that passed through the test section was cooled to room temperature with the heat exchanger and a cooler. After depressurization, impurities contained in the test water were removed using the ion exchange resin column and returned to the water tank.
Particle coating with composite shell in a pan granulator
Published in Particulate Science and Technology, 2022
Andrey A. Lipin, Alexandr G. Lipin
The experimental technique for studying the batch granulation process was as follows. Firstly, particle size distribution (PSD) analysis was performed. Then, the initial sample of urea granules was fed into the pan granulator 1 (Figure 2). An aqueous solution of a binder was fed continuously from a tank 6, using a metering pump 7, into a disk atomizer 8. The atomizer sprayed the solution onto the surface of moving particles. The desired amount of powdery coating material was loaded manually at different time intervals throughout the process. The binder allows the particle surface to adsorb the coating material. The drying and heat treatment of the material was carried out with an infrared heater 9. The tilt angle was varied in the range of 45° to 75°, and the rotation frequency was changed in the range of 30–65 rpm.
Forming characteristics during the high-pressure resin transfer molding process for CFRP
Published in Advanced Composite Materials, 2019
Beom Jeong Han, Yong Chai Jeong, Churl Min Kim, Roh Won Kim, Myungchang Kang
Figure 1 shows the HP-RTM process for high-speed production of CFRP. As shown in Figure 1(a), the mold is partially closed after the preform of the carbon fiber sheet is placed in the cavity of the lower mold. A gap of less than approximately 2 mm was maintained between the mold surface and preform. The resin and hardener were mixed in the high-pressure mixing head with the metering pump and injected into the mold. The mixture of the resin and hardener flows into the cavity and partially impregnates the preform. The upper mold is completely closed and pressed by the press machine when the injection of the resin was complete. The resin was cured in the mold and molded into a CFRP part [17]. Figure 1(b) shows the process steps of the standard HP-RTM with a curing time of 5 min [18].