Abstract:
A method and system for creating a vacuum in a dry sprinkler system to evacuate water when the sprinkler system is inactive and to assist in the quick dispersion of water through the sprinkler system when a fire event occurs are disclosed. A vacuum apparatus establishes a vacuum that is within the design pressure capability of sprinkler drops in the sprinkler system. A pressure regulator monitors the pressure and automatically activates the vacuum apparatus when a vacuum loss is detected. A valve is activated when a fire event occurs so that water is drawn through the sprinkler system quickly.

Description:
RELATED APPLICATIONS AND CLAIM OF PRIORITY  
       [0001]     This application claims priority to and incorporates by reference in its entirety, U.S. Provisional Application No. 60/569,954 entitled “Fire Protection Sprinkler System” and filed May 11, 2004. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention generally relates to fire protection systems. More particularly, the present invention relates to a fire protection sprinkler system that includes a vacuum to evacuate the system when the sprinkler heads are not activated.  
       BACKGROUND  
       [0003]     Most commercial buildings, hotels, hospitals and nursing homes are required by law to include fire extinguishing sprinkler systems in the building. In addition, sprinkler systems are increasingly used in residential applications, including apartment buildings, condominiums and homes. The sprinkler systems are generally housed in or near the ceilings of one or more floors of the building and are made of pipes having varying diameters. The systems are fed by a water supply line and are designed to deliver large amounts of water to a fire upon activation. The systems are typically activated when smoke or intense heat is detected.  
         [0004]     Sprinkler systems can be classified in two general categories: “wet” systems and “dry” systems. A “wet” system&#39;s pipes are permanently filled with water, which is immediately expelled through the sprinkler heads when the system is activated. Although wet systems have the benefit of immediate delivery of water upon activation, they are not suitable for installations where any part of the system is at risk for damage caused by freezing water. In addition, wet systems can create water damage if a sprinkler head malfunctions or is opened accidentally.  
         [0005]     “Dry” systems are available for installations where a risk of freezing exists or where avoidance of water flow or leakage is critical. In current dry systems, the system&#39;s pipes are generally empty of water. Air pressure is used in such systems to force air out of the pipes. When the air pressure is relieved, water flows into the pipes and is delivered to the heads. The resistance created by the water forcing the air out adds to the time that it takes for the water to reach the sprinkler heads.  
         [0006]     Current dry systems contain several disadvantages. First, since water must be delivered to all points in the system in a very short period of time upon activation, several standards have been set that restrict the design of the system. For example, the National Fire Protection Association (NFPA) requires most current dry systems to have an increased design area in order to account for a larger fire that may result from waiting for the water to arrive at the affected area of the system. To ensure that the water reaches all points in a system quickly, the NFPA also restricts most dry systems to a 750-gallon capacity. Moreover, the NFPA prohibits such systems from using a grid design layout unless the designer can demonstrate that the water will arrive at the portion of the system that is most remote from the source within 60 seconds. Thus, a system that allows for reduced pipe sizes, as well as grid/loop designs that can allow for quick water delivery to the sprinkler heads, is desirable. Second, since compressed air is almost always present in the system, moisture that is naturally present in the air can condense on the outside of the system and corrode the inside of the system, especially in cold temperature environments.  
         [0007]     A few prior art systems have attempted to overcome these problems by applying a vacuum to the system. However, these systems also contain several disadvantages. For example, U.S. Pat. No. 5,927,406, to Kadoche, describes a sprinkler system to which a vacuum is applied. The system activates and delivers water to the system whenever the system is returned to atmospheric pressure. However, the system in Kadoche requires specially designed sprinkler heads. Moreover, the system contains no means of distinguishing between a pressure change that is due to a fire and a pressure change that results from a sprinkler head malfunction.  
         [0008]     U.S. Pat. No. 6,715,561, to Franson, describes another vacuum system that requires specially designed sprinkler heads. The requirement of specially designed heads creates a significant financial deterrent to the use of the existing vacuum systems. Moreover, the system poses a significant risk of water damage to a building and its contents if any sprinkler head malfunctions or is damaged.  
         [0009]     Consequently, a need exists for a vacuum dry sprinkler system that can be used in existing sprinkler installations without requiring substantial redesign of the system or the use of specially designed sprinkler heads.  
         [0010]     A need also exists for a method of delivering water through an existing sprinkler system without requiring substantial redesign of the system, as well as through new systems in a manner that allows for reduced pipe sizes, and for grid and loop systems.  
         [0011]     This invention is directed to solving one or more of the above-described problems.  
       SUMMARY  
       [0012]     Before the present methods and systems are described, it is to be understood that this invention is not limited to the particular methodologies and systems described, as these may vary. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.  
         [0013]     It must also be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, reference to a “sprinkler head” is a reference to one or more sprinkler heads and equivalents thereof known to those skilled in the art, and so forth. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Although any methods, materials, and devices similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred methods, materials, and devices are now described. All publications mentioned herein are incorporated by reference. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.  
         [0014]     In an embodiment, a dry sprinkler system includes a network of pipes and sprinkler drops, a first water source, a vacuum apparatus that maintains a regulated vacuum on the network under normal operation, and a first valve that is activated upon a detection of a fire event so that activation of the valve causes water to be delivered to the network from the first water source. The regulated vacuum may be a pressure that is within the design capability of the sprinkler system, such as a pressure that is between about two inches and about ten inches of mercury. Optionally, the first valve is a three-way valve having a first port that is connected to the first water source, a second port connected to a second water source, and a third port connected to the network, such that first valve is activated by water from the second water source being removed from the second opening. However, two-port valves, and other multi-port valves, are possible. In an embodiment, a pressure sensor causes the system to prevent the delivery of water from the first source to the network unless a fire event is also detected. In addition, a heat or smoke sensor, such as a solenoid, may cause the system to permit the delivery of water from the first source to the network when a fire event is also detected.  
         [0015]     In an alternate embodiment, a system for applying a vacuum to a dry sprinkler system includes a valve having at least three ports, including a first water source port, a second port, and a water delivery port. The valve also includes a seat that prevents water from being delivered from the first water source port to the water delivery port in normal operation. The system also includes a vacuum apparatus that creates a vacuum on a sprinkler piping network when the sprinkler piping network is connected to the water delivery port. The system also includes an actuator that, upon a detection of a fire event, causes the seat to open so that water may be delivered from the first water source port to the water delivery port. Optionally, the system may also include a pressure regulator, and the vacuum apparatus may include a power source and switch. The switch may be activated when the pressure regulator detects a pressure that is above a predetermined level. Optionally, actuator includes a water source and fire detector, wherein the water source is directed away from the second port upon detection of the fire event.  
         [0016]     In an alternate embodiment, a method of creating a vacuum in a dry sprinkler system includes the steps of: (i) connecting a vacuum apparatus to a sprinkler system, wherein the apparatus includes a vacuum pump and a power source; (ii) establishing, by the vacuum apparatus, a vacuum in the sprinkler system, wherein the vacuum is within the design pressure capability of sprinkler drops in the sprinkler system; (iii) monitoring, by the pressure regulator, the vacuum; and (iv) automatically increasing, by the vacuum apparatus, the vacuum when the pressure regulator detects a pressure drop in the sprinkler system. The method may also include removing one or more sprinkler heads from their corresponding sprinkler drops in the sprinkler system after the vacuum is established to siphon trapped water from the sprinkler drops. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     The accompanying drawings, which are incorporated in and form a part of the specification, illustrate various embodiments and, together with the description, serve to explain the principles of the various embodiments.  
         [0018]      FIG. 1  is a block diagram illustrating exemplary features of a dry sprinkler system according to an embodiment.  
         [0019]      FIG. 2  is an expanded view of several of the features originally illustrated in  FIG. 1 .  
         [0020]      FIG. 3  is an expanded valve that may be used in an embodiment.  
         [0021]      FIG. 4  is a side view of an exemplary vacuum application apparatus.  
     
    
     DETAILED DESCRIPTION  
       [0022]     Referring to  FIG. 1 , an embodiment of a novel dry sprinkler system is illustrated in a block diagram. The exemplary system includes a three-way valve  10  that receives water from a water source  16  via a source pipe  18 . The valve controls the delivery of water from the source  16  to a plurality of sprinkler heads  21  via one or more pipes  20 . Preferably, each port of the valve  10  is connected by a water-resistant gasket or seal (not shown) to its corresponding piping (i.e., the source  16 , piping  22  and/or the sprinkler network  20 ).  
         [0023]     To ensure that the pipes  20  are at least substantially empty when the sprinkler system is inactive, the valve may include a seat  11  that seals off the flow of water from source  16  when water pressure is also present from source  24 . The seat  11  may be made of any durable, water-resistant material. In a preferred embodiment, the seat  11  is made of brass with a hard neoprene rubber coating. However, those skilled in the art will recognize that the seat  11  may be made of other materials as well. The seat  11  may be connected to a first hinge  12  around which the seat may swivel when a camber  15  is lifted. The camber  15  may be connected to a second hinge  13 . A pin or piston  14  may open the seat  11  and allow delivery of water from source  16  to the sprinkler heads  21  when the pin  14  pushes against the camber  15 , typically because of a reduction or loss of water pressure from pipe  22 .  
         [0024]     The valve  10  may be any commercially available three-way valve, such as those made by Victaulic Co., Reliable Automatic Sprinkler Co., and Globe Fire Sprinkler Corp. However, for such commercially available valves, modification may be required to ensure that the seat  11  does not pull up and allow water to flow from the source  16  into the system  20  when a vacuum is applied. Such modifications may include using a stronger hinge  12  and/or a stronger spring-loaded camber  15  and hinge  13  mechanism.  
         [0025]     When the sprinkler system is inactive, the sprinkler piping  20  is substantially dry. The piping  20  is preferably maintained at a vacuum during periods of inactivity. The applied vacuum is preferably below atmospheric pressure at a vacuum pressure between about 2 inches and about 10 inches of mercury. The vacuum may be applied to the piping  20  by a vacuum apparatus  50  that draws air from the piping through a vacuum pipe  40 . The vacuum pipe  40  must be airtight to permit the vacuum apparatus  50  to apply the vacuum. Optionally, the vacuum apparatus  50  may be capable of applying higher pressures such as vacuum pressures in the range of about 27 to about 30 inches of mercury. In such an embodiment, a pressure regulator  42  may be provided to step down the applied vacuum to a desired level (i.e., a level within the design pressure capability of the sprinkler drops in the sprinkler system). For example, the vacuum level may be between about 2 inches and about 10 inches of mercury. Other vacuum levels are possible without departing from the scope of the invention. Once the vacuum has been applied, one or more of the sprinkler heads  21  may be removed to allow the siphoning of trapped water from the corresponding sprinkler drops.  
         [0026]     The pin  14  may position the camber  15  to keep the seat  11  in place after the vacuum is applied to the piping system  20 . The pin  14  may be held in place by water pressure from a pipe  22  that receives water from a source  24 . Source  24  may be the same source as the primary water source  16 , or it may be a different source. The pin  14  triggers the camber  15  and releases the seat  11  when water pressure from pipe  22  is relieved. Water pressure may be relieved in pipe  22  in one or more ways.  
         [0027]     In an embodiment, a first solenoid  28  may relieve the water pressure in pipe  22  by triggering a first valve  26  to open and allow water from source  24  to be directed to a drain  34 . The first solenoid  28  may be activated by the detection of heat and/or smoke that would be indicative of a fire that requires activation of the sprinkler system  20 . The first solenoid  28  may include heat and/or smoke detection capabilities, or it may be connected to a separate heat and/or smoke sensor (not shown).  
         [0028]     In an embodiment, a vacuum loss detection mechanism  32  may relieve the water pressure in pipe  22  by triggering a second valve  30  to open and allow water from source  24  to be directed to the drain  34 . The vacuum loss detection mechanism  32  may directly detect an accidental loss of vacuum in the piping system  20 , or a vacuum sensor (not shown) located within the piping system  20  may trigger the vacuum loss detection mechanism  32 .  
         [0029]     In an embodiment, either the heat/smoke sensor or the vacuum loss detection mechanism  32  may direct water from source  24  away from the piping system  20  toward the drain  34 . However, in an alternate embodiment, both the heat/smoke sensor and the vacuum loss detection mechanism  32  must be activated in order to direct water from source  24  away from the piping system  20  toward the drain  34  and open the seat  11  in valve  10 . In an alternate embodiment, the vacuum loss detection mechanism  32 , when activated, may signal the vacuum apparatus  50  to apply a vacuum to the piping system  20 .  
         [0030]     When the sprinkler system is inactive, the vacuum apparatus  50  may only apply a vacuum to the piping system  20  until the piping system achieves a desired vacuum level. Once the desired vacuum level is achieved, the vacuum apparatus  50  may turn off or switch to a power saving or dormant mode.  
         [0031]      FIG. 2  is an expanded view of several of the features originally illustrated in  FIG. 1 . For example, the three-way valve  10 , the solenoid  28  and valve  26 , the vacuum valve  30 - 32 , the drain  34 , the vacuum regulator  42  and various pipes are shown. The specific structure, including pipe sizes and configuration, illustrated in  FIG. 2  is exemplary only and is not intended to limit this scope of the invention.  
         [0032]      FIG. 3  is an expanded view of an exemplary three-way valve  10  that may be used in accordance with the invention. The valve illustrated in  FIG. 3  is one such as may be commercially available and known in the prior art.  FIG. 3  illustrates several elements of valve  10 , including a seat  11 , hinge  13  and spring-loaded camber  15 . The seat  11  may include a seal, such as  18 , which may be made of, for example, rubber or another water resistant material.  
         [0033]     Referring now to  FIG. 4 , a side view of an embodiment of a vacuum apparatus  50  is shown. The apparatus includes a vessel  52 , upon which a frame  54  may be mounted that supports items such as a power source  56  and a vacuum pump  58 . The power source  56  may be, for example, a one horsepower electric motor. The power source  56  may be operably connected to and may supply power to the vacuum pump  58 . The vessel  52  may have a suction inlet with a ball valve  62  on one end, and a sight glass  60  on the opposite end. Drain valve  64  may extend from the bottom of vessel  52 , with an optional check valve  66  and drain pump  72 . The vessel  52  may be mounted on one or more supports  66  with optional apertures for conveniently mounting to skids or wheels (not shown). A power cord  68  may extend from the power source  56  and may be coiled on a hook (not shown) located on the apparatus  50 . The apparatus  50  may also include one or more of a pressure gauge  70 , an on/off switch  74 , an air filter  76 , a pressure regulator and a muffler  80 .  
         [0034]     The vessel  52  is preferably an ASME compliant tank. While the vessel  52  may be any size, the vessel  52  preferably has a 10 to 50 gallon capacity, and most preferably is of a size that does not make the apparatus  50  difficult to move and/or transport. However, vessels of other sizes, such as vessels having five-gallon capacities or larger capacities, are possible. The vessel  52  may be made of a material that is impervious to water, such as a metal. Although a tank is depicted as vessel  52  in  FIG. 4 , it is recognized that other containers may be contemplated within the scope of this invention. In this embodiment, the drain valve  64  is approximately 1.5 inches in diameter and may protrude from the bottom of vessel  52 . However, it is recognized that other means for draining the vessel  52  may be contemplated within the scope of this invention.  
         [0035]     Vacuum pumps  58  contemplated for use with the invention may include a piston, a fan and one or more screw type pumps (e.g., cylinder bounded devices for moving fluids such as air). In an embodiment, a piston type vacuum pump  58  operating at 1725 revolutions per minute and capable of generating a reduced pressure/pressure differential of approximately 0 to approximately 30 inches of mercury may be used. In such an embodiment, the vacuum pump  58  may create a stable reduced pressure of about 10 inches of mercury. It is also recognized that any vacuum pump capable of generating a stable reduced pressure of about 10 inches of mercury may be used and still fall within the scope of the invention, as most current sprinkler systems use couplings that can withstand a pressure of up to 10 inches of mercury. However, systems may operate at higher or lower vacuum pressures and still fall within the scope of the invention.  
         [0036]     The power source  56 , illustrated in  FIG. 4 , may be, for example, an electric motor capable of generating about three horsepower. However, it is also recognized that any power source or engine capable of generating power sufficient to operate the vacuum pump  58  may be used and still fall within the scope of the invention. For example, the stability of the reduced pressure may increase and an increased number of sprinkler heads  21  may be removed at once by using a motor with increased maximum horsepower.  
         [0037]     As indicated by  FIG. 4 , the power source  56  provides power to the vacuum pump  58 . In this embodiment, the power source  56  is positioned on the frame  54  above and on the opposite side of the vessel  52  from the vacuum pump  58 . A coupling guard may cover a coupling that runs between the power source  56  and the vacuum pump  58 . In the embodiment depicted in  FIG. 4 , the power source  56  has an external power source, e.g. an electric outlet, and power cord  54 . Other structures and engine types are possible within the scope of the invention. In addition, other components of the apparatus  50  may be positioned differently, but still fall within the scope of the invention.  
         [0038]     In an embodiment, a method of removing water includes providing an apparatus such as that discussed herein, connecting the apparatus to a sprinkler system, and creating a reduced pressure within the system. The connection may occur in several places, such as a gang valve. The main gang drain valve may reside on the inside or outside of the building which houses the sprinkler system, and a multi-story building may have only one gang drain valve for the entire system, or one gang drain valve for each floor of the building. In this embodiment, once a vacuum pressure is established in the apparatus using the vacuum pump  58 , water is removed from the sprinkler drops by unscrewing the sprinkler head  21  from each sprinkler drop. Once each sprinkler head  21  is unscrewed, the vacuum pressure established by the vacuum pump  58 , which creates a pressure differential between the pressure in the sprinkler system  20  and the atmospheric pressure outside the sprinkler system, creates a siphon or vacuum that removes the trapped water from the sprinkler head drop. The trapped water is siphoned from the sprinkler head drop through the sprinkler system pipes, possibly all the way to the vessel  52 . The system may use a filter to prevent water from backing up from the vessel  52  into the vacuum pump  58 .  
         [0039]     It is recognized that the apparatus may be attached to any point on the sprinkler system where a hose can be connected such that an airtight seal may be created between the hose and the sprinkler system  20 . The sprinkler system  20  may be breached at any point on a sprinkler head drop such that the inside of the pipe drop is exposed to air at the atmospheric pressure, causing the siphon that transports the trapped water in the sprinkler drop to the vessel  52  on the apparatus  50 . An alternate embodiment of the vacuum apparatus is illustrated in co-pending U.S. patent application Ser. No. 10/040,094, of which  FIGS. 1-4  and the accompanying text are incorporated herein by reference. Alternate vacuum devices may also be used. However, the apparatus described above and the apparatus illustrated in U.S. patent application Ser. No. 10/040,094 may be used in preferred embodiments since such an apparatus may provide additional benefits as described in U.S. patent application Ser. No. 10/040,094.  
         [0040]     The present system may provide several advantages. For example, water delivery to remote areas of a piping system may occur more quickly than in normal dry systems, since the relief of a vacuum system effectively sucks water from the water source through the piping. In other words, water is quickly pulled through the pipe, rather than pushed through the pipe from a water source. This effect also provides benefits for residential systems and other sprinkler systems that use plastic pipes, which may not be able to endure, or which may react with loud sounds to, the pressure caused when water is pushed through the pipes. Further, unlike existing vacuum systems, the vacuum pipe in the present inventive system need only operate until the vacuum level is achieved in the piping system. Once the vacuum level is achieved, the vacuum apparatus may shut off or may switch to a dormant mode until the vacuum pressure is relieved, either by an air leak or by activating the sprinkler system because of heat for a fire.  
         [0041]     It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in this description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Hence, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.  
         [0042]     As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.