China
Africa
Explore chapters and articles related to this topic
Troubleshooting and maintenance
Published in Ian C. Turner, Engineering Applications of Pneumatics and Hydraulics, 2020
For hydraulic systems the following regular maintenance routines are recommended: check oil level in all tankscheck regulators and filterscheck pump drivescheck valve linkage for damaged partscheck for external oil leakscheck cylinder bearings and mountingsdiscuss with the operators of the system any noted difference in performance or unusual events.For both pneumatic and hydraulic systems the frequency of carrying out maintenance checks should be established on the basis of equipment and component manufacturers’ recommendations together with the user’s own field experience with the system.
The Cable and the Membrane
Published in Bjørn N. Sandaker, Arne P. Eggen, Mark R. Cruvellier, The Structural Basis of Architecture, 2019
Bjørn N. Sandaker, Arne P. Eggen, Mark R. Cruvellier
The word “pneumatic” refers to devices or structures that in some way operate by help of air pressure. The common balloon is perhaps the quintessential example of such a “structure” that takes its form and volume from internal air pressure, and one that we investigated briefly in the previous section in order to get somewhat familiar with the membrane equation and to see by just how much the rubber membrane is stressed in normal conditions of inflation. For the balloon, an internal air pressure which is higher than the external atmospheric pressure pre-stresses and stabilizes the extremely light rubber membrane so that its roughly spherical shape is maintained while being able to be subjected to moderate external loads. We are well aware, however, that there are certain problems associated with the stability of balloons: they typically leak their internal air pressure and deflate over time, and concentrated loads (point loads) tend to deflect the rubber membrane excessively and may rather easily puncture it.
Engineering
Published in H. Selcuk Agca, Giancarlo Cotone, Introduction to Process Plant Projects, 2018
H. Selcuk Agca, Giancarlo Cotone
Powering of instruments are either electrical (DC or AC) or pneumatic. Electric power for instrumentation and automation is usually fed through UPS (uninterrupted power supply) that keeps supplying power usually for some fraction of an hour on a black out. As certain portions of the facilities usually constitute critical loads that require to be operated during any extended power outages for plant safety, such loads are also connected also to DGs (diesel generators). UPS and DG constitute emergency power generation system of a facility which is crucial for safe shut down of the process unit during an extended power outage. Pneumatic systems are powered by instrument air systems equipped with compressors, dust and oil filters, air driers, air receivers, pressure regulators and instrument air piping, tubing and fittings.
Dispersion characteristics of the plug flow hazardous waste by multiple gas jets
Published in Journal of the Air & Waste Management Association, 2023
Guangming Guo, Xiaowen Zheng, Miao Wu
As shown in Figure 4, the test system was mainly composed of the main body of the spray gun, the pneumatic system, and the hydraulic system. The main body of the spray gun mainly included a feed inlet, an outlet and pushing piston. A pneumatic system mainly included the air compressor, flowmeter, pressure gauge and the switch valves. So the multiple gas jets from different nozzles were formed. The hydraulic system could provide multiple pushing speeds. The working principle of the experimental system is as follows: First, the material was added from the upper feed inlet of the main body of the spray gun, and the hydraulic cylinder pushed the piston, which consequently pushed the material, causing it to slide along the inner wall of the charging cylinder to the outlet. Afterward, the air source was opened, and the materials were dispersed under the impact of multiple gas jets.
Innovative design of pneumatic conveying and foreign substance cleaning and dust removal system
Published in Australian Journal of Mechanical Engineering, 2019
The pneumatic conveying is a material conveying method. In the conveying process, the material and the air are mixed at a certain mixing ratio, and the driving air flow transports the material from one place to another place through airtight pipes. The pneumatic conveying system consists of air compressor, feeder, pipeline and separator. Based on the different air pressures, the pneumatic conveying can be divided into two types: the negative pressure and the positive pressure pneumatic conveying.In the negative pressure pneumatic conveying system, the air compressor is installed at the end of the system. During the running of the air compressor, a negative pressure will be formed in the airtight pipeline system, and the differential pressure existing between the inside and outside of the pipeline will suck the air into the conveying pipe, and the materials will also been sucked into the pipeline by the airflow. The dust in the conveying material will not overflow because the inner air pressure is lower than the outer air pressure of the pipeline. Thus, the negative pressure pneumatic conveying system is considered environmental protection.In the positive pressure pneumatic conveying system, the air compressor is installed at the starting end of the system. During the running of the air compressor, a positive pressure will be formed in the airtight pipeline system. The material must be filled into the pipeline through a seal pressure feeding device, and the compressed air will transport the material to working place. The dust in the conveying material can overflow because the inner air pressure is higher than the outer air pressure of the pipeline. Thus, the positive pneumatic conveying system has the possibility of environmental pollution.
Mechanical design and control of inflatable robotic arms for high positioning accuracy
Published in Advanced Robotics, 2018
Hye-Jong Kim, Akihiro Kawamura, Yasutaka Nishioka, Sadao Kawamura
In this paper, we propose a modified PEBVS control scheme to be used for inflatable robotic arms. When we apply this method to inflatable robotic arms, the following problems occur:Inflatable robotic arms contain much larger errors in their kinematics than general robots with rigid links do. Therefore, it is more difficult to exactly calculate a gravity compensation term and the desired angle. The gravity compensation and the P feedback control on the coordinates of the joint angles are not useful for controlling inflatable robotic arms.In inflatable robotic arms, the joint angle vector also contains a large error due to the deformation of the inflatable links. Thus, even if the joint angles measured by the sensor converges to the desired angle, the position of the tip of the robotic arms do not converge to the desired positions. Therefore, feedback on the joint angles is not suitable for inflatable robotic arms.Pneumatic systems have high-order dynamics and a delay in outputting the torque due to the compressibility of air, the control time for the pressure regulation, and so forth. Even though velocity feedback is needed for the damping effect, it is difficult to obtain a satisfactory damping effect from the feedback control of the pressure regulators.Because of these problems, we only adapted the position PI feedback control mechanism and did not use the joint angle feedback control mechanism and compensation of gravity. In this section, we outline the modified PEBVS control scheme for a 3-DOF inflatable robotic arm. This method uses a stereo camera set. The modified PEBVS scheme can be expressed by the following equation: