Enclosure enclosed rooms

Enclosures Enclose room or equipment and place under negative pressure. Enclose hazardous operations such as sample points. Seal rooms, sewers, ventilation, and the like. Use analyzers and instruments to observe inside equipment. Shield high-temperature surfaces. Pneumatically convey dusty material. 

Enclosures—enclose equipment/room and use negative pressures... 

X-ray dilJiaction units generate an x-ray beam that is used to check the crystalline structure of incoming semiconductor wafers. Under certain circumstances, it may not be practical to fiilly contain the x-ray beam in an interlocked enclosure. In this instance, operators may be required to wear radiation finger badges, and controls similar to those used for a Class 4 lasers are used (e.g., enclosed room with limited access, operator training, enclosing the x-ray beam as much as practical, etc.). 

Hot jobs should be scheduled for the cooler part of the day, and routine maintenance and repair work in hot areas should be scheduled for the cooler seasons of the year. Other administrative controls are to reduce the physical demands of work. For example, reduce the amount of excessive lifting or digging with heavy ol ects provide recovery areas such as air-conditioned enclosures and rooms use shifts, such as early morning, cool part of the day, or rtight work use intermittent rest periods with water breaks use relief workers use worker pacing assign extra workers and limit worker occupancy, or the number of workers presenf especially in confined or enclosed spaces. 

When special contaminating processes are located in a seini-enclosed parr of a room as in Fig. 7.18, the exhausts should be located so that a displacement flow is created through the passage into the semi-enclosure. With this arrangement there may be no need for a door, which may be very practical. 

Enclosed fires may exhibit fire growth characteristics as shown in Figure 5-5. Unlike gaseous or liquid fuels, there may be a considerable fire growth period in which temperatures and overall heat release is low and the fire is localized. As the fire becomes fully developed, the entire room volume can become engulfed in flames, finally, as air is depleted or fuel is consumed, a decay period occurs. In many cases, an enclosure fire will be starved for air ("ventilation-limited"), and the available airflow becomes the limiting factor for the fuelburning rate. 

Where it is possible for flammable or toxic gas or vapor released within a hazardous area to migrate to the inlets for HVAC systems serving nonhazardous enclosed areas such as control rooms, detection systems should be installed in those HVAC inlets or connecting ductwork. Detection should be provided in HVAC system intakes if the building, room, or enclosure served is not electrically classified and a flammable (or toxic) gas or vapor could feasibly be drawn into the area, either by mechanical ventilation systems or by differential pressures. The detection system should alarm and automatically shutdown the HVAC to prevent gas or vapor concentration in the protected space from reaching the flammable or toxic range. 

Bottle systems are more varied, whether for glass, polyethylene terephtha-late (PET) or other plastic. Bottles are rinsed with oxonia solution and then sterile water prior to filling. The filler is generally of a non-contact type (it does not touch the bottles) and product is either weighed in or measured volumetrically. Caps are also chemically sterilised (unless a foil closure is used) and applied on a capper monoblocked with the filler, enclosed in a high efficiency pure air (HEPA) filtered enclosure. The filler and final rinser are in a class 100 room and file operator wears full protective clothing to prevent infection of the product. 

Ventilation in special rooms or chambers. Lower-cost standard motors are enclosed with light sheet metal and pressurized with uncon-taminated air or other inert purge gas. A housing pressure of 1 to 2 lb is sufficient to exclude hazardous gas from the equipment enclosure. In some cases, positive-pressure ventilation of an entire room or building is recommended to allow use of less expensive standard electrical equipment throughout. 

Thermal detectors are not exclusively operated at room temperature. When cooled to very low temperatures, (3.10) or (3.11) would still represent the ultimate performance i f the detector were enclosed completely in a cooled enclosure at the operating temperature. Thus if we were to envisage a detector operating in outer space and cooled to the Universe s background temperature (say 3K) (3.11) would indicate a limiting sensitivity of... 

Outside the cell room itself, the transformers and rectifiers may be indoors or outdoors but always are enclosed to restrict entry to their immediate vicinities. The hazards are the high supply voltage itself, the possibility of explosion, and the risk of flash bums in case of a ground fault. The maintenance of this equipment and associated circuit breakers, switches, and relays is a subject for specialists, and other personnel should not enter the enclosures while equipment is activated. 

For multiple-array systems, cubic arrays of 216 air-spaced units of U(93.2) metai spheres centered in cubic cells were examined. Three distinct cubic arrays were considered, each composed of 10-. IS-, and 20-kg units. The parameters of each array were selected so the array would be critical if it were totally reflected by water. Nine identical arrays were arranged in a square pattern at the center of a square room enclosed by 406-mm-thick concrete. The total average fractional solid angle i subtended at the center array was determined by the approximate method described in TIO-7016 (Ref. 5). Depending on its location in the room, a single array will have different values of keff due to the different contributions of neutron reflection from the concrete enclosure. The array keff is maximum when the array is at a comer of the room and minimum when it is located at the center of the room. 

Compressors, pumps Vibration-isolated mounting in enclosed soundproofed rooms. Machines preferably separated from one another by partitions or with individual enclosures. Ventilation or air intake openings of such rooms should have louvred sound attenuators. Intake and outlet silencers for the compressors. Pressure pipelines to have sound-damping expansion joints and acoustically sealed wall inlets. Pressure release pipelines to have silencers. Additional sound insulation for compressed air pipelines to suppress rushing noises. Sound-insulated enclosed portable compressors represent the current "state of the art" for use in quarrying operations. 

Enclosed locations that may be susceptible to build-up of combustible gases are typically provided with ventilation systems that will disperse the gases or provide sufficient air changes to the enclosures such that leakages will not accumulate. Typical examples include battery rooms, gas turbine enclosures, offshore enclosed modules, etc. 

A drip tight enclosure that is intended to prevent contact with the enclosed apparatus and in addition is so constructed as to exclude falling moisture or dirt but is not dust tight. Type 2 enclosures are suitable for applications where condensation may occur, such as encountered in cooling rooms and laundries. 

Flashover - In relation to the behaviour of fire in buildings and other enclosed spaces flashover is the point at which the whole room or enclosure where the fire started becomes totally involved in fire. It is caused by the radiated feedback of heat. Heat from the growing fire is absorbed into the upper walls and contents of the room, heating up the combustible gases and furnishings to their autoignition temperature. This build-up of heat in the room triggers flashover. 

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