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Application and Selection
Published in Béla G. Lipták, Flow Measurement, 2020
These units pump and meter the fluid at the same time. The two basic types are the plunger pump, which provides reasonable accuracy, and the diaphragm-type, used for dangerous or contaminated fluids. The advantages of a metering pump include that it is self-contained, and is simple to install. It is reasonably accurate, but subject to errors caused by variations in pressure and viscosity. The limitations are that their cost is fairly high, the process fluid must be clean, there is a need for periodic recalibration, and pump operation is no guarantee of product discharge.
Pumps
Published in Paul N. Cheremisinoff, Handbook of Water and Wastewater Treatment Technology, 2019
A plunger pump differs from a piston pump in that it has a plunger reciprocating through packing glands causing the displacement of liquid from the cylinder. In this type pump, considerable radial clearance exists between the plunger and cylinder walls. Plunger pumps usually are thought of as single acting in the sense that only one end of the plunger is used for pumping liquid. Figure 20 provides details of the operating principle of a single-acting, horizontal plunger pump. As shown, a piston serves the role of the plunger (1), reciprocating in cylinder (2) and sealed with a packing gland (3). The internal cylinder surface of a plunger-type pump does not require as high a degree of finishing as does a piston pump. Also, leakage is readily minimized by tightening or replacing the packing gland. Plunger pumps are well suited to handling suspensions and viscous fluids because of their large radial clearances and ability to generate high pressures.
Application of fuzzy comprehensive evaluation in fault diagnosis of plunger pump
Published in Fei Lei, Qiang Xu, Guangde Zhang, Machinery, Materials Science and Engineering Applications, 2017
Chao Wu, Di Wu, Xuyao Mao, Hongyuan Ding, Junhua Hu, Yiou Liu
Plunger pump is one of the most commonly used type of pump, the main fault symptoms of which are small pressure, large pressure fluctuations, low flow, high vibration, high temperature and large leakage, etc and the main fault causes are badly worn of plunger and cylinder, badly worn of slipper and swash plate, badly worn of cylinder block and the oil pan, the slipper loose and bearing damage, etc[2–4]. The fault of plunger pump is complex and diverse, with the following characteristics: (1) Fault is not a single symptom, in most cases the symptoms of several faults occur simultaneously, such as: system pressure fluctuations are usually accompanied by vibration. (2) It is ambiguous correspondence between fault symptoms and causes, which means that a failure symptoms may be caused by a variety of causes, while a fault cause may lead to a variety of symptoms.
Rough sets-based prediction model for increasing safety of thermal power plants
Published in Energy Sources, Part B: Economics, Planning, and Policy, 2019
Vladimir Brtka, Vesna Makitan, Ljiljana Radovanovic, Zoran Zivkovic, Oliver Momcilovic
According to (Wang 2013) RST has strong practicability in condition monitoring and fault diagnosis. In this work, RST is used for fault diagnosis of the five-plunger pump. The proposed approach aims at identifying the basic events occurring in the running condition of the pump. As this approach involves subjective judgments by domain experts, imprecise, inconsistent, missing or vague data, RST is considered to be a suitable tool. Based on the premise of retaining the principal information of the pump running conditions, RST can help in reducing the faults. In this investigation eight features were selected from the frequency spectra obtained from the vibration signals tested on the horizontal direction of the hydraulic-end of the pump, while RST was used to recognize and diagnose the pump faults. Different operating states of the pump have been represented by six decision rules. Results show that this approach is a good basis for the detection and diagnosis of the pump faults.
New batch and continuous systems for converting hydrogen from water hyacinth
Published in Chemical Engineering Communications, 2018
Duangkamol Ruen-ngam, Pongsiri Jaruyanon
A continuous pilot plant system was constructed to confirm the feasibility of a large capacity operation. The flow rate was 0.5 l/h closed to supercritical water conditions (T = 374°C, P = 22 MPa). The hydrothermal continuous system is shown in Figure 2, and it includes four zones: feed preparation, preheating, reactor, and product zones. The pressure in the system was produced by a plunger pump. All tubes in the system were made from SS-316. The outside diameter of reactor zone was ½ inch and consisted of eight pieces with 2 m long (Swagelok®, Solon, OH, USA). The pressure in the system was controlled by the pressure release valve. The temperature, pressure, and electric power usage in each zone were recorded at 1 min intervals with a clamp-on power logger (PW3360; HIOKI, Hioki, Japan). The gas sample was collected in a gas bag and then analyzed by GC. The total volume of gas was measured as the volume of water displaced in a 50 cm ID cylindrical tank. In this system three various types of materials; glucose, cellulose + lignin and dried water hyacinth were tested, as shown in Table 2.
Thermal balance and gap flow of high-pressure, large-scale plunger pairs
Published in Heat Transfer Engineering, 2023
Shendan Zhao, Jie Dong, Hao Pang, Yinshui Liu, Zhenyao Wang
During the plunger pump experiment, the system pressure was adjusted through the loading valve. Given the experimental conditions, no temperature test was performed on the plunger sleeve. In the experiment, TESTO 835-H1 infrared thermometer was used to measure the surface temperature of the five plungers (Table 2). When the plunger surface temperature did not change with time, the plunger pair at this time was considered to have reached a state of thermal balance. At rated pump speed, the average temperature of the five plungers at different pressures was measured, as shown in Figure 8. The temperature of the plunger pair increased rapidly with time and reached the temperature value after about 120 minutes.