Claims:1. A fire restraining multi-tier busway system (100) comprising of:
a plurality of busway tier (10);
a housing (30) configured around each busway tier (10) of the plurality of busway tier (10), the housing (30) having a top housing and a bottom housing for enclosing the busway tier (10) therebweteen;
atleast four mounting blocks (50) assembled on the housing (30) in a way to create three compartments therein including a first outer compartment (42a), a second outer compartment (42b) and an inner compartment (44) disposed therebetween; and
a fire-resistant thermal insulation material provided within the three compartments for restricting spread of fire therefrom, the fire-resistant thermal insulation material including a refractory material (70) and an intumescent material (90), the refractory material (70) packed within the first outer compartment (42a) and the second outer compartment (42b) whereas the intumescent material (90) packed within the inner compartment (44), the intumescent material (90) being capable of expanding upon exposure to fire for sealing gaps created in response thereof;
wherein the plurality of busway tier (10) are stacked together using mounting bolts (20) such that the corresponding compartments of the plurality of busway tier (10) gets aligned facing each other thereby creating three continuous chambers therebetween, the three continuous chambers including a first outer chamber (92a) and a second outer chamber (92b) packed with the refractory material (70) and an inner chamber (94) packed with the intumescent material (90) and disposed therebetween such that the first outer chamber (92a) acts as a first fire barrier, the inner chamber (94) acts as a second fire barrier and the second outer chamber (92b) acts as a third fire barrier thereby restricting fire to a localized area and preventing the fire from spreading therefrom.

2. The fire restraining multi-tier busway system (100) as claimed in claim 1, wherein the housing (30) is rectangular in shape.

3. The fire restraining multi-tier busway system (100) as claimed in claim 1, wherein the refractory material (70) preferably includes fibre-wool material.

4. The fire restraining multi-tier busway system (100) as claimed in claim 1, wherein the intumescent material (90) preferably includes an epoxy resin.

, Description:Field of the invention
The present invention relates to busway, and more particularly provides a fire restraining multi-tier busway system for arresting the spread of fire through the busway in wall crossing points in event of a short circuit after the busway is installed within the building.
Background of the invention
Busways are installed in various orientations in buildings for supplying electrical power to any area of the building. A typical application of busway is as riser mains in the building. Busway risers (vertical busway) are installed economically in a high-rise building to distribute lighting and air conditioning loads. However, the conventionally used busways do not have in-built fire safety features in case of a sudden emergency event such as a short circuit.
The ability to arrest or delay the spread of fire in buildings is an important safety feature and has even become a regulatory requirement. Several technologies are available for fire-barriers. Most solutions employ the use of enclosure materials capable of withstanding high temperature and pressures. Modern busways however use aluminium alloy enclosures for the purpose of enhancing heat dissipation. Most cellulosic fires can reach upto 800 0 C within a few hours. This inhibits the use of the aluminium alloy housings which melt at 660 0 C.
Therefore, there exists a need to provide an improved fire resistant busway which overcomes the above mentioned drawbacks of the existing technologies thereby allowing the busways to withstand heat for longer duration of time in the event of a sudden outbreak of fire caused due to a short circuit.
Objects of the invention
The primary object of present invention is to provide a fire- resistant, easy to install and compact busway system for installation within buildings.
Another object of present invention is to prevent busway from being melted at a high temperature so as to avoid the occurrence of busway explosion in the event of an electric short circuit.
Yet another object of the present invention is to restrict fire to a localized area and preventing spread of fire therefrom in the event of a sudden electric short circuit.
Summary of the invention
The present invention provides a fire restraining multi-tier busway system. The system comprises of a plurality of busway tier, housing, four mounting blocks and a fire- resistant thermal insulation material. The housing is a rectangular housing configured on each busway tier of the plurality of busway tier and includes four mounting blocks assembled thereon in a way forming three compartments therein, including a first and a second outer compartment and an inner compartment formed therebetween. The fire- resistant thermal insulation material is packed within the three compartments, and includes a refractory material and an intumescent material. Particularly, the refractory material is packed within the first and the second outer compartments, whereas the intumescent material is packed within the inner compartment. The intumescent material is capable of expanding upon exposure to fire, particularly for sealing gaps created due to fire. The plurality of busway tier are stacked together one above the other such that the corresponding first, second outer compartments and the inner compartment of two opposite busway tier face each other thereby creating three continuous chambers therein, including a first and a second outer chamber and an inner chamber therebetween. The system is installed in buildings such that in event of short circuit, leading to prolonged fire outbreak, the three chambers acts as a fire barrier avoiding spread of fire therefrom. In the event of prolonged fire, causing housing of busway tier to melt, the first outer chamber acts as a first fire barrier, the inner chamber acts as a second fire barrier whereas the second outer chamber acts as a third fire barrier. Thus, the three fire barriers restrain fire from spreading from a localized area and prolong the breach time by several hours even for the most intense cellulosic fire.
Brief description of the drawings
Figure 1 shows a perspective view of the fire restraining multi-tier busway system, in accordance with the present invention, crossing the wall-opening during installation within the building;
Figure 2 shows a perspective view of a busway tier having mounting blocks assembled thereon, in accordance with the present invention;
Figure 3 is a busway tier of figure 2 showing fire-resistant thermal insulation material packed within the three compartments, in accordance with the present invention;
Figure 4 is a perspective view showing assembling of the plurality of busway tier, in accordance with the present invention;
Figure 5 is a perspective view of the fire restraining multi-tier busway system, in accordance with the present invention;
Figure 6 shows a sectional view of figure 5 along line A-A showing the inner chamber filled with intumescent material, in accordance with the present invention;
Figure 7 is another view of the fire restraining multi-tier busway system of present invention passing through a wall during installation within the building;
Figure 8 shows a sectional view of figure 7 along line B-B showing the outer chamber filled with the refractory material, in accordance with the present invention;
Figure 9 shows a sectional view of figure 7 along line C-C showing the outer chamber filled with the refractory material, in accordance with the present invention;
Figure 10 is view similar to figure 8 showing the closure of the wall opening using metallic sheets after installation within the building, in accordance with the present invention; and
Figure 11 is a graph of the ISO-834 cellulosic fire cure showing the burning characteristics of the cellulosic fire, in accordance with the state of art.
Detailed description of the invention
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
The present invention provides a fire restraining multi-tier busway system for restricting and restraining spread of fire in event of an electric short circuit occurring after installation within the building. Particularly, the system acts as a fire barrier restricting fire to a localized area and preventing the spread of fire therefrom.
This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Accordingly, the present invention provides a fire restraining multi-tier busway system (100), (hereinafter referred to as “the system (100)”) for preventing spread of fire within buildings. The system (100) provides a heat resistant busway having resistance to heat and not melting even at higher temperature, thus avoiding occurrence of busway explosion in event of an electric short circuit.
Referring to figures 1 to 11, the system (100) comprises of a plurality of busway tier (10), housing (30), mounting blocks (50) and a fire- resistant thermal insulation material. The plurality of busway tier (10) is stacked together forming a gap therebetween. The housing (30) is configured on each busway tier (10) of the plurality of busway tier (10) for protection thereof. In an embodiment, the housing (30) is a rectangular housing around the busway tier (10) and includes a top housing and a bottom housing provided for covering the busway tier (10). In another embodiment, the housing (30) is made up of aluminium.
The housing (30) of the each busway tier (10) includes atleast four mounting blocks (50) assembled thereon. In a preferred embodiment, four mounting blocks (50) are assembled on the housing (30) of each busway tier (10). Particularly, four mounting blocks (50) are assembled on top and bottom housing separately. The mounting blocks (50) are assembled onto the housing (30) such that three compartments are formed therein, including a first outer compartment (42a), a second outer compartment (42b), and an inner compartment (44) formed therebetween, as shown in figure 2. The fire-resistant thermal insulation material is filled within the three compartments created using the mounting blocks (50). The fire-resistant thermal insulation material includes a refractory material (70) and an intumescent material (90). In an embodiment, the refractory material (70) is packed within the first outer compartment (42a) and the second outer compartment (42b), whereas the intumescent material (90) is packed within the inner compartment (44) of each busway tier (10) of the plurality of busway tier (10), as shown in figure 3. The intumescent material (90) is capable of expansion upon exposure to fire. Particularly, the intumescent material (90) expands and covers any crevices/gaps created upon exposure to fire. In an embodiment, the refractory material (70) and the intumescent material (90) is in form of slabs. In a preferred embodiment, the refractory material (70) includes, not limiting thereto, a fibre-woll material, whereas the intumescent material (90) includes, not limiting thereto, an epoxy resin. However, it is evident to a person skilled in the art that any other material having like property can be used as the refractory and the intumescent material.
The plurality of busway tier (10) in the system (100) are assembled together one above the other such that the corresponding mounting blocks (50) face each other as shown in figure 4. Particularly, the plurality of busway tier (10) present within the system (100) are stacked together such that the three compartments of the busway tier (10) disposed above, aligns exactly facing each other with the respective three compartments of the busway tier (10) present below, thereby forming three continuous chambers therein including, a first outer chamber (92a), a second outer chamber (92b) and an inner chamber (94) formed therebetween. Particularly, the plurality of busway tier (10) in the system (100) is stacked together such that the bottom housing of the busway tier (10) disposed above, faces the top housing of the busway tier (10) present below such that the corresponding mounting blocks (50) and the respective three compartments of the busway tier (10) aligns exactly with respect to each other thereby forming three continuous chamber- the first outer chamber (92a) and the second outer chamber (92b) filled with the refractory material (70) as shown in figures 7 to 9, and the inner chamber (94) disposed therebetween filled with the intumescent material (90) as shown in figures 5 & 6. The plurality of busway tier (10) in the system (100) is assembled, stacked and tightened together using mounting bolts (20).

The system (100) is commonly installed in tall buildings. Particularly, the system (100) is placed within a wall opening (142), as shown in figure 1; of the buildings such that the inner chamber (94) filled with the intumescent material (90) gets aligned geometrically with central plane (144) of a wall (150). The gaps remaining between the system (100) and the wall opening (142) are then filled with the refractory material (70) and the wall opening (142) is then closed using metallic sheets (170) as shown in figure 10. The metallic sheets (170) are made up of ferrous material thereby minimizing the gaps present in between the wall opening (142) and the system (100). Any gaps left open thereafter are sealed using the intumescent material (90) from either side of the wall opening (142) to ensure that fire does not spread through the gaps/crevices in between the plurality of busway tier (10).
Most building material used in construction of the buildings includes cellulose. Figure 11 shows the typical burning characteristics of a cellulosic fire, showing the ISO-834 curve. In the event of intense and prolonged fires on either side of the wall opening (142) having the system (100) placed therein, the housing (30) and copper conductors (not shown) melts first. The melting point of Aluminium is around 6600C and that of Copper is around 10850C, and most carbon steels melts beyond 13000C. Following melting of the housing (30) and the copper conductors, the first outer chamber (92a) gets exposed to fire, and restrains spread of fire therefrom thereby creating a first barrier for the fire to cross-over. Further, in the event the first outer chamber (92a) is breached by the fire, the chamber lying immediate to the first outer chamber (92a) restrains the spread of fire therefrom. Thus, the fire crossing through the first outer chamber (92a) is restrained by the inner chamber (94) packed with the intumescent material (90), thereby creating a second barrier for the fire to cross-over. Furthermore, in the event the fire crosses the inner chamber (94), the second outer chamber (92b) lying immediate next to the inner chamber (94) creates a third fire barrier to restrain the fire from crossing and spreading.

The system (100) is thus a three stage fire restrain system (100) adapted to prolong the fire breach time by several hours even for the most intense cellulosic fire thereby providing fire safety feature for higher buildings. The system (100) is an integral part of the building once installed therein thus providing resistance to penetration by fire. Further, in an event of the fire outbreak, the system (100) is adapted for compartmentalizing and restraining the fire to the localized area. Since busway shafts are hollow allowing free passage of air between the busway and the busway shaft, and even between the plurality of busway tier (10) through the gaps present therebetween, use of the system (100) helps in restraining fire in event of fire outbreak and in delaying the spread of fire from the localized area.
Advantages of the present invention
1. The system (100) helps in arresting and delaying the spread of fire in buildings thereby providing the fire safety feature in tall buildings.
2. The system (100) is adapted to withstand high temperature and pressures and functions as a fire barrier in buildings.
3. Low melting point materials can be used in manufacturing the housing (30).
4. The system (100) is easy to install, economic in manufacture, and can be used for restraining cellulosic fires.
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system (100), structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.