Horizontal exits

Use of horizontal exits in fire-rated walls that may be required for warehouse subdivision. 

Personnel door(s) must be swinging type. Door swings in direction of exit travel when used os an exit. Two personnel fire doors shown, each swinging in direction of exit travel such as a condition where each door serves as a horizontal exit from its respective fire area. 

Overhead fire door must be arranged for automatic closing when the fire resistance rated wall serves as a horizontal exit wall. 

The portion of an exit route that is generally separated from other areas to provide a protected way of travel to the exit discharge from the effects of an incident. An example of an exit is a 2-hour fire-resistance-rated enclosed stairway that leads from the fifth floor of an office building to the outside of the building. Exits include exterior exit doors, exit passageways, horizontal exits, and separated exit stairs or ramps. See also Fire Escape. 

Exit Capacity Life safety standards give capacities for exits. The capacities vary with occupancy, which adjusts all occupancies to a similar total exiting time. The standards also vary for stairs, ramps, doors, horizontal exits, and escalators. The number of exit units affects capacities required for an occupancy. 

For horizontal exits, solids may build up in the exit duct and dump periodically back into the main riser (van der Meer et al., 1997). 

The maximum allowable toto/travel distance from any location in a fab (H-6 or H-7) to the outside of a building, an enclosed stairway, a horizontal exit or an exit passageway may not exceed 200 feet, and then only when the last 100 feet are within an exit corridor in compliance with UBC 1005,an<7thebuildingissprinklered (UBC 1003.4). Exit corridors shall be arranged to allow travel from any point in two directions to an exit, except for dead-ends not exceeding 20 feet in length. 

Horizontal exits shall be as specified in UBC 1008. A horizontal exit is an exit from one building into another building or through or aroxmd a wall constructed as required for a two-hour area separation. 

Service corridors are intended for the transportation of HPMs within an H-6 occupancy and are governed by UBC 220,307.11.4 and UFC 5107. Service corridors shall be classified as Group H, Division 6 occupancies. Service corridors shall be separated from exit corridors as required by UBC Section 307.11.2.1. The maximum distance of travel from any point in a service corridor to an exterior exit door, horizontal exit, exit passageway, enclosed stairway or door into a fabrication area shall not exceed 75 feet. 

Another possibiUty is to enclose only the working, top part of the horizontal belt in a pressure vessel and pass the belt through the sides of the vessel. The operation must be intermittent because the belt cannot be dragged over the support surface with the pressure on, and the entrance and exit ports for the belt must be sealed during operation to prevent excessive losses of air. The movement of the belt is intermittent and is synchronized with decompression in the vessel therefore, the entire vessel volume must be depressurized in every cycle and this is wasteful. There is also an inevitable downtime. There are no problems with discharging the cake because this is done at atmospheric pressure. 

Horizontal rotary machines employ multiple molds in a horizontal plane on a rotary turret. As each mold approaches the extmder die exit, it opens to accept the parison and then closes. The parison is then blown into the bottle shape. The extmder must extmde on an intermittent basis or be intermittently withdrawn to provide a parison for each passing mold. 

A horizontal column is typified by the Brodie Purifier, which is shown schematically in Figure 26. Feed enters the column between recovery and refining sections, and crystals exit the refining section and pass through a purifying section. The purifying section is a wash column in which the crystals are contacted with melt generated at the bottom of the column. 

Figure 22-8 shows the features of a horizontal center-fed column [Brodie, Au.st. Mech. Chem. Eng. Tran.s., 37 (May 1979)] which has been commercialized for continuous purification of naphthalene and p-dichlorobenzene. Liquid feed enters the column between the hot purifying section and the cold freezing or recovery zone. Ciystals are formed internally by indirect cooling of the melt through the walls of the refining and recovery zones. Residue liquid that has been depleted or product exits from the coldest section of the column. A spiral conveyor controls the transport of solids through the unit. 

Horizontal Blowdown Drum/Catch Tank This type of drum, shown in Fig. 26-16, combines both the vapor-liquid separation and holdup functions in one vessel. Horizontal drums are commonly used where space is plentiful, such as in petroleum refineries and petrochemical plants. The two-phase mixture usually enters at one end and the vapor exits at the other end. For two-phase streams with very high vapor flow rates, inlets may be provided at each end, with the vapor outlet at the center of the drum, thus minimizing vapor velocities at the inlet and aiding vapor-hquid separation. 

The adsorbers are usually built of steel, and may be lagged or left unlagged the horizontal type is shown in Figure 28. The vapor-laden air is fed by the blower into one adsorber which contains a bed of 6- to 8-mesh activated carbon granules 12 to 30 inches thick. The air velocity through the bed is 40 to 90 feet per minute. The carbon particles retain the vapor only the denuded air reaches the exit, and then the exhaust line. The adsorption is allowed to continue until the carbon is saturated, when the vapor-laden air is diverted to the second adsorber, while the first adsorber receives low-pressure steam fed in below the carbon bed. The vapor is reformed and carried out by the steam. The two are condensed and if the solvent is not miscible with water, it may be decanted continuously while the water is run off similarly. After a period which may be approximately 30 or 60 minutes, all the vapor has been removed, the adsorbing power of the charcoal has been restored, and the adsorber is ready to function again, while adsorber No. 2 is steamed in turn. 

Yilmaz recommends that the maximum velocity in the exit from the horizontal thermosiphon reboiler be the work ofCollinsd ... 

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