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Fluid Power Systems
Published in Anton H. Hehn, Fluid Power Troubleshooting, 1995
Power unit installation requires first that the cleaned reservoir is positioned on antivibration material or mounts and then bolted in place. Check that the pump motor assembly is correct and the pump and motor shafts are connected with a suitable flexible coupling or similar device. Also, be sure that the shaft alignment between the drive motor and pump is correct. The pump and motor assembly should be mounted on antivibration material or mounts and then bolted in place. Connect the pump suction line to the reservoir through a shutoff valve or suction filter, using a flexible suction hose. There will be some relative movement between the pump and reservoir which will transmit vibration and may damage a rigid pipe. The suction hose is internally reinforced to prevent collapse when the inside is subjected to pressures lower than atmospheric (vacuum). It is advisable to use a lockable shut-off valve in the suction line, if one is needed; this prevents unauthorized closure of the valve which could lead to pump damage.
Investigation on the performance and application of a new design of foam generator used for fire extinguishment in underground coal mines
Published in Combustion Science and Technology, 2018
Xin-xiao Lu, Hong-qing Zhu, Chao Hu, Hong-ru Zhao
Briefly, the procedure for applying foams for mine fire extinguishment is as follows. First, mix the foaming agent and water in a specified adding device, and then convert this mixture into expansion foams using the proposed foam generator. Finally, infuse foams into the fire zone through foam delivery pipes or drill holes. Figure 9 illustrates the layout of foam extinguishing system. It was set around the new open-off cut with an elevation of −460 m, while the previous working face is at −390 m. The altitude difference is 70 m. The foam delivery pipe, overall length of 330 m, extended to the goaf 30 m from the working face. In order to inspect the effect of foam infusion, an observation hole was set in the foam delivery pipe. As shown in Figure 10, the new foam generator was fixed on the roadway wall conveniently through hooks and flanges. Foaming agent was stored in a bucket, which was sucked into the adding device through a suction hose. The occupying space of the new equipment was so small that it would not hamper the normal transportation operation in the roadway. This foam extinguishing system uses compressed nitrogen and static pressure water available in the roadway as powers, without any additional electric pumps, eliminating explosion risk caused by electrical sparks, which has intrinsic safety when used in underground coal mines.
Physical employment standard for Canadian wildland fire fighters; identifying and characterising critical initial attack response tasks
Published in Ergonomics, 2018
Robert J. Gumieniak, Jim Shaw, Norman Gledhill, Veronica K. Jamnik
There was a significantly lower (p ≤ 0.05) VO2 during Pulaski trenching, chain saw clearing/support, carrying intake/suction hose and set-up/starting a pump than each of the five most demanding tasks. When considered together with the data in Table 1, in which subject matter experts rated Pulaski trenching as the lowest importance with moderate exertion and a moderate frequency of occurrence during an IA, this task was not included in the final WFX-FIT circuit (Gumieniak, Gledhill, and Jamnik 2018). Further, when Pulaski trenching was initially included in the WFX-FIT during pilot testing, it provided no differentiation between participants. One-way analysis of variance indicated a significant difference between agencies in VO2 for the hose pack carry and the advance charged hose (p ≤ 0.05). Post hoc Bonferroni tests indicated that the VO2 for the hose pack carry was greater in British Columbia than both Saskatchewan and New Brunswick and the VO2 while advancing the charged hose was greater in British Columbia than Saskatchewan. The mean HR response while performing all tasks was 160 ± 16 bpm, and the RPE ratings from the IA WFF indicated that performing these critical tasks was ‘somewhat hard’ to ‘very hard’ (Borg 1982). The VO2, HR response and RPE measurements determined that the following four critical tasks identified in the physical demands analysis justified inclusion in the WFX-FIT protocol – carry a pump on the back, hand carry a pump, carry a hose pack containing four sections of hose and advance charged hose. It also confirmed that the physical demands of IA wildland fire fighting in steep mountainous terrain (British Columbia) were higher than in other terrains (New Brunswick and Saskatchewan) (Table 6).
Stable 15N isotopes in fine and coarse urban particulate matter
Published in Aerosol Science and Technology, 2021
Hanna Wiedenhaus, Laura Ehrnsperger, Otto Klemm, Harald Strauss
Furthermore, particle losses cannot be excluded due to the length of the suction hose. According to Kumar et al. (2008), however, the losses for particles larger than 0.02 µm are moderate. Since the losses should also have no influence on the isotope ratios, we also assume this influence to be negligible.