Smoke Protection System

Abstract

A smoke protection system for high rise buildings supplies a level of the building filled with smoke from a fire with air so as to displace the smoke from the building and reduce the hazard of suffocation.

Description

BACKGROUND OF THE INVENTION

Most modern high rise building structures which have been built in the last few years and which will be built in the future are constructed in accordance with local building codes that require various structural features that tend to isolate a fire on any floor or level of the building to its own level so that the fire will not spread vertically throughout the building. In addition, various alarm systems, sprinkler systems and other hazard-deterrent systems have been devised for reducing the likelihood of the occurrence of fires in buildings where a large number of people are present and where escape from the building is difficult. One of the more hazardous elements which results from fire in a multiple level building is the presence of smoke in the building, particularly at the level of the building where the fire is present. While the fire may be contained within a single level of the multiple level building and eventually extinguished, the hazard to the occupants on the level where the fire is located is significantly increased if the smoke from the fire is allowed to spread through its level of the building. While various "smoke doors" and other devices have been developed in an effort to contain undesirable smoke at its origin so as to prevent the smoke from spreading throughout the building, it is more desirable to remove the smoke from the building, if possible.

SUMMARY OF THE INVENTION

Briefly described, the present invention comprises a system for removing smoke from a level of a multiple level building so as to reduce the hazard of smoke inhalation to persons occupying the building. The level of the building which is on fire and contains smoke is supplied with breathable air so as to displace the smoke from the building, by urging the smoke out of a broken window or other passage to the outside.

An elevator in the multiple level building is equipped with a high capacity fan which is arranged to move air from the elevator shaft into the elevator car. The elevator car is automatically called to the level of the building which contains smoke, its doors opened and its fan energized, thus drawing air from the elevator shaft, into the elevator car, through the open elevator doors, and into the level of the building which contains smoke. Since the external windows of the building adjacent the fire are usually broken because of the extreme heat emitted from the fire, the air supplied to the level of the building by the system displaces the smoke through the broken windows to the outside of the building, and the level is supplied with fresh air at least about the common area adjacent the elevators. Thus, any persons present on the level of the building which contains smoke will be able to travel from their location in the building, through the common area, to a fire escape, etc., without suffocating due to smoke inhalation.

In a second embodiment of the invention, air is supplied to the level of the building which contains smoke by a system which uses fans to supply the fire escape stairwell with air and an automatic door opener which opens the fire escape door between the stairwell and the level of the building which contains smoke.

Thus, it is an object of the present invention to provide a smoke protection system wherein smoke is removed from a level of a multiple level building by displacing the smoke from the building with a supply of fresh air.

Another object of the present invention is to provide a method of protecting occupants of a multiple level building in which a fire is present, by removing the smoke from the vicinity of the building.

Other objects, features and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view of a single level of a multiple level building.

FIG. 2 is a partial schematic elevational view of a multiple level building, showing the elevator.

FIG. 3 is a schematic detail perspective view of a portion of the elevator shaft and the elevator car in the shaft.

FIG. 4 is a block diagram of the control system utilized with the smoke protection system.

FIG. 5 is a schematic plan view of a single level of the multiple level building, similar to FIG. 1, but showing a modified form of the invention.

FIG. 6 is a schematic block diagram of the control system, similar to the diagram of FIG. 4, but showing a control system suitable for use with the modified form of the invention illustrated in FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Referring now in more detail to the drawing, in which like numerals indicate like parts throughout the several views, FIG. 1 illustrates a single floor or level 10 of a multiple level building 11, with each floor typically including a plurality of rooms 12 located around its outside walls, an elevator shaft 13 located interiorally of the building and extending vertically thereof, elevator cars 14 and 15 which move through the elevator shaft, a common area 18 in the vicinity of the elevator cars and the exterior rooms 12, and one or more fire escape stairwells 19 and 20 which open into the common area 18.

As is illustrated in FIG. 3, one or more of the elevator cars 15 are equipped with a fan 21. While the fan 21 is illustrated as a propeller fan located centrally in the top wall of the elevator car, it will be understood that the fan can be a centrifugal blower or other type fan and can be located off-center in the top wall of the elevator car or located on another wall of the elevator car as may be expedient in the design construction of the elevator system. Fan 21 is arranged to move air from the elevator shaft 13 into the elevator car 15, through the elevator door opening 22 and laterally out of the elevator car onto the floor level where the elevator car is located. As is illustrated in FIG. 1, more than one elevator car can be equipped with a fan.

Since the elevator shaft 13 is of larger horizontal cross-sectional area than the elevator cars which occupy the shaft, the fans mounted on the elevator cars are able to move air from above and from below the elevator cars into the elevator cars and out onto a level of the building.

As is illustrated in FIG. 2, a mechanical fresh air supply is provided for filling the elevator shaft 13 with air from outside the building. The exhaust of blower 25 communicates with the elevator shaft and functions to supply the elevator with air. Blower 25 can be located at virtually any level along the elevator shaft, preferably at a level where it has immediate access to a suitable supply of outside air. For instance, blower 25 can be located at the basement level or the roof level of the building, if appropriate. Moreover, more than one blower 25 can be provided, and the blowers can be positioned at various levels. If a suitable supply of air is accessible to the elevator shafts, as from air leakage about the elevator doors located vertically above and below the elevator car, the blower 25 can be eliminated.

One or more smoke detectors 26 are located on each level of the building for the purpose of detecting smoke on its level and actuating an alarm system and the smoke protection system disclosed herein. In addition, a manual alarm switch 28 is located on each level of the building so that the fire alarm and smoke protection system can be actuated manually.

As is illustrated in FIG. 4, the smoke detectors 26 and manual switches 28 from each level of the building are interconnected into the alarm control center 29. The alarm control center is of conventional construction in that is actuates a fire department alarm 30, a local alarm 31, and an anunciator panel 32. In addition, the alarm control center actuates the elevator control system through elevator control unit 34. The elevator control unit 34 causes at least one of the elevator cars 15 to first move in a downward direction to the lower level or main level of the building and open its elevator doors, and to notify its passengers to make their exit from the elevator car by illuminating a sign 35 inside the elevator car and sounding an alarm 36. After a suitable time delay in which the passengers of the elevator car are expected to leave the elevator car, the elevator control unit 34 energizes the fan 21 on the elevator car, closes the elevator doors, moves the elevator car to the level 10 of the building which contains smoke emitted from a fire on that level and opens the elevator doors. The fan 21 draws air from the elevator shaft into the elevator car, then through the elevator door opening, and out into the common area 18 of the level. The heat from the fire usually causes several of the external windows of the building to become cracked and broken, thereby creating an air passage to the outside, so that the smoke from the fire is displaced through the broken windows to the outside of the building.

If the building has more than one elevator, all of the elevators can be used in the system, with each elevator car including a fan and keyed into the system so as to respond to the smoke detector.

In buildings which have elevator shafts that are divided from each other, by separate elevator shafts or by partitions located in a single elevator shaft between the path of the elevator cars, one or more of the elevator fans can be programmed to move air from the elevator shaft into the car and then out onto the level of the building which contains smoke, as previously described, and one or more of the other elevator cars can have its fan programmed to draw air and smoke from the level of the building which contains smoke into the elevator car, and then discharge the air and smoke into its elevator shaft. With this arrangement, a broken window or other air vent to the outside of the building does not have to be present in order to displace smoke from the building.

When a smoke detector 26 is energized and the system is actuated, and if the system is used in a building which includes a blower 25, the blower 25 will also be energized through the alarm control center 29 so as to supply the elevator shaft with the air pressure necessary to carry out the function of the system. If the pressure in the elevator shaft is below atmospheric pressure, a substantial amount of air leakage to the elevator shaft will occur through the openings at each elevator door along the elevator shaft, so that a supply of air can be provided from the other floors above and below the level of the building which contains smoke.

As is illustrated in FIG. 5, where an alternate form of the invention is disclosed, a smoke protection system can be provided which does not utilize the elevator cars. A plurality of blowers 40 communicate between the fire escape stairwell 20 and a source of air, such as the air in the elevator shaft 13, and an automatic door opener 41 is connected to each door 42 which opens into the fire escape stairwell 20. As is illustrated in FIG. 6, when the smoke detector 26 detects smoke on its level of the building 11, its door opener 41 is energized, the fan 40 is energized, and the alarm control center 25 is energized. Door opener 41 causes the fire escape stairwell door 42 to open, and fan 40 moves air from the elevator shaft into the stairwell into the vicinity of the open door, causing air to flow from the elevator shaft into the stairwell and then out onto the level of the building which contains smoke. In order that the air pressure in the stairwell 20 adjacent the open door 42 be maintained at a level sufficient to move the air from the stairwell out into the level of the building which contains smoke, the fire escape stairwell is divided into vertical sections by internal walls and doors (not shown). This requires a fire escape stairwell fan 40 to be located at each section; however, the sections of the fire escape stairwell can span several levels of the building, thus requiring fewer wall partitions and fans.

The smoke detectors 26 located on each level of the building can comprise any of the conventional smoke and fire detectors, such as ionization detectors which are responsive to smoke and/or heat, or obscuration of light detectors. The detectors function to close a switch in response to smoke and/or fire and actuate the alarm system and smoke control system. Typical smoke detectors are the FM-1001, FM-1002, FM-1600, all of which are produced by Firemark, a division of Rixson, Inc. of Franklin Park, Illinois. Door closing apparatus 41 as previously described can comprise any of the conventional door opening systems, such as the FM-972 holder-release produced by Firemark. The elevator control unit which causes the elevators to respond to the smoke detectors are the type manufactured by Otis Elevator Co. of New York City and which are described at Page 136 of the September, 1972 issue of Fire Journal. These and other similar devices are available through various conventional sources.

While this invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.

Claims

I claim:

1. A method of displacing smoke or the like from a level of a multiple level building comprising detecting smoke in a level of the multilevel building, moving an elevator car to the level of the building which contains smoke in response to the detection of smoke, moving air from the elevator shaft through the elevator car and into the level of the building which contains smoke to raise the air pressure in and to displace the smoke from the level of the building which contains smoke.

2. The method of claim 1 and wherein the step of moving air into the level of the building which contains smoke comprises opening the elevator doors, and moving air from the elevator shaft through the elevator car and the elevator door opening into the level of the building which contains smoke.

3. The method of claim 1 and further comprising moving the elevator car to a floor of the building below the level of the building which contains smoke to discharge passengers therefrom.

4. A method of exhausting smoke or the like from a level of a multiple level building comprising moving an elevator car to the level of the building which contains smoke, opening the elevator doors, moving air from the elevator shaft through the elevator car and elevator door opening into the level of the building which contains smoke to displace the smoke, and flowing the air and smoke out of the level of the building which contains smoke.

5. The method of claim 4 and wherein the step of flowing the air and smoke out of the level of the building which contains smoke comprises moving a second elevator car to the level of the building which contains smoke, opening the elevator doors of the second elevator car, and moving the air and smoke from the level of the building containing smoke through the second elevator car and into the elevator shaft of the second elevator car.

6. A method of displacing smoke or the like from a level of a multiple level building having a detecting means comprising detecting smoke with the detecting means in a level of the multilevel building, opening the door between the fire escape stairwell and the level of the building which contains smoke in response to the detection of smoke by the detecting means, and moving air through the fire escape stairwell and through the door opening into the level of the building which contains smoke to raise the air pressure in and to displace the smoke from the level of the building.