Перевести. geared traction machines are driven by ac or dc electric motors. geared machines use worm gears to control mechanical movement of elevator cars by "rolling" steel hoist ropes over a drive sheave which is attached to a gearbox driven by a high-speed motor. these machines are generally the best option for basement or overhead traction use for speeds up to 3 m/s (500 ft/min).historically, ac motors were used for single or double-speed elevator machines on the grounds of cost and lower usage applications where car speed and passenger comfort were less of an issue, but for higher speed, larger capacity elevators, the need for infinitely variable speed control over the traction machine becomes an issue. therefore, dc machines powered by an ac/dc motor generator were the preferred solution. the mg set also typically powered the relay controller of the elevator, which has the added advantage of electrically isolating the elevators from the rest of a building's electrical system, thus eliminating the transient power spikes in the building's electrical supply caused by the motors starting and stopping (causing lighting to dim every time the elevators are used for example), as well as interference to other electrical equipment caused by the arcing of the relay contactors in the control system.methods of removing condensed waterthere are at least four ways to remove condensed water from the air conditioner. however, each solution has its pros and cons.atomizingatomizing, also known as misting the condensed water, is one way to dispose of the condensed water. spraying ultra-fine water droplets onto the hot coils of the air conditioner ensures that the condensed water evaporates quickly.though this is one of the best methods to dispose of the condensed water, it is also one of the costliest because the nozzle that atomizes the water easily gets choked. the majority of the cost goes to maintaining the entire atomizing system.boilingdisposing of condensed water works by firstly collecting the condensed water and then heating it to above boiling point. the condensed water is eventually evaporated, thereby disposing of it.consumers are reluctant to employ this system because of the high rate of energy used just to dispose of this water.cascadingthe cascading method works by flowing the condensed water directly onto the hot coils of the air conditioner. this eventually evaporates the condensed water.the downside of this technology is that the coils have to be at extremely high temperature for the condensed water to be evaporated. there is a chance that the water might not evaporate entirely and that would cause water to overflow onto the exterior of the car.drainage systemdrainage system works by creating a sump to collect the condensed water and using a pump to dispose of it through a drainage system.it is an efficient method, but it comes at a heavy price because the cost of building the sump. moreover, maintaining the pump to make sure it operates is very expensive. furthermore, the pipes used for drainage would look ugly on the exterior. this system also cannot be implemented on a built project.​

Davidovaliza    2   05.04.2019 12:26    4