Elevators machine rooms

This drive can be used for a wide range of car sizes but has a limit to the speed of travel of approximately 2.5 m/s. The elevator machine room is usually located above the elevator shaft. However, bottom-of-shaft machine rooms are not unknown, although they tend to be more costly. 

Each elevator or group of elevators requires a elevator machine room that should be designed complete with ... 

GENERAL CONSIDERATIONS Cooling Towers and Legionnaires Disease Elevator Machine Rooms Energy Conservation Equipment Maintenance Equipment Noise and Vibration Evaporative Cooling Fire and Smoke Control Dampers Outdoor Air Perimeter Heating Process Loads Room Air Motion OCCUPANCIES Clean Rooms Computer Rooms Offices Test Cells... 

There are many different types of equipment that are not ditectly connected to the process. One example is elevators, which can influence the ventilation system both when moving and when standing. In addition to the need for ventilation of the elevator, elevator shaft, and machine room, the moving elevator can induce airflows that change the air distribution and airflows in different parts of the building. 

Have a machine room located above the elevator shaft ... 

A recent innovative machine-room-less traction elevator (ISIS) from ThyssenKrupp takes full advantage of the properties of p-aramid in the design of the hoist cable and associated traction sheaves [130-133]. The cable has three times the life of a steel rope, is smaller in size, and weighs 90% less than a steel rope at a comparable strength rating. The smaller size permits the use of smaller sheaves thereby decreasing torque requirements and operating costs. No lubrication is required because the inner strands are Teflon coated. Finally, the cable transmits less noise and provides a smoother, quieter ride. 

Hoistways, machine rooms, pits, and overhead areas must be kept clean, and all equipment must be regularly maintained and inspected. In order to prevent trips and falls, handrails, gates, alarms, and guards are necessary around landings, elevator doors, and hoistway doors and gates. Emergency elevator evacuation procedures must be developed and communicated to personnel. 

Properties. Uranium metal is a dense, bright silvery, ductile, and malleable metal. Uranium is highly electropositive, resembling magnesium, and tarnishes rapidly on exposure to air. Even a poHshed surface becomes coated with a dark-colored oxide layer in a short time upon exposure to air. At elevated temperatures, uranium metal reacts with most common metals and refractories. Finely divided uranium reacts, even at room temperature, with all components of the atmosphere except the noble gases. The silvery luster of freshly cleaned uranium metal is rapidly converted first to a golden yellow, and then to a black oxide—nitride film within three to four days. Powdered uranium is usually pyrophoric, an important safety consideration in the machining of uranium parts. The corrosion characteristics of uranium have been discussed in detail (28). 

Many metals are naturally brittle at room temperature, so must be machined when hot. However, particles of these metals, such as tungsten, chromium, molybdenum, etc., can be suspended in a ductile matrix. The resulting composite material is ductile, yet has the elevated-temperature properties of the brittle constituents. The actual process used to suspend the brittle particles is called liquid sintering and involves infiltration of the matrix material around the brittle particles. Fortunately, In the liquid sintering process, the brittle particles become rounded and therefore naturally more ductile. 

After several days to 2 weeks at the elevated cure temperature, the propellant has been converted to a macroscopically homogeneous mass by mutual diffusion of nitrocellulose and plasticizers. The propellant charge is then permitted to cool to room temperature, casting fixtures are disassembled, cores are extracted, and finally the propellant end surfaces are machined to conform to required dimensions. 

Last but not least, one should not forget that for practical applications the hardness at room and at a high temperature is only one of many properties which determine the applicability of a material. Further mechanical properties, such as fracture toughness under static and dynamic load, coefficient of friction, corrosion resistance, and reactivity with the material to be machined at room as well as at elevated temperature are decisive for most applications. 

The monotonic bending tests and static fatigue tests were performed on a three-point bending system with a span of 16 mm as shown in figure 1. The crosshead speed of the monotonic bending tests was O.S mm/min. The tests were performed at room and elevated temperatures. From the bending moment measured as the specimens fractured, Mf, the following equation was used to evaluate the nominal fracture stress (Onk) of the machined specimens. 

In press-brake formed or stretch-formed angles and channels, and in machined extrusions, joggles with radii smaller than the minimum bend radii for the metal at room temperature, or joggles with length-to-depth ratios of less than about 6 to 1, are more successfully formed at elevated temperature. Forming tern-... 

---