Ventilating fan for fire fighting

Abstract: A manhandleable ventilating fan assembly (10) has a set of fan blades (36) carried by a fan hub (34) secured to the front end of a shaft (16) rotatably mounted in a housing (22) for a water-driven turbine runner (20) having radial-flow turbine vanes (20′) on its rear face. The turbine housing has rearwardly-facing inlet and outlet connections (24 and 26) for fire hoses, the inlet leading into an inlet chamber having a control valve (60) through which water passes to a volute (46) supplying the turbine vanes (20′) and having a diameter no greater than that of the fan hub (34). Water mist can be added from nozzles (70) to air driven by the fan. The assembly is tiltably mounted on a frame (93) supportable on wheels (100). A by-pass circuit may bleed off and replace some of the water circuitry through the turbine, and a driving pump on a fire truck, to avoid over-heating.

Description: This invention relates generally to the field of fans and, more particularly, to portable fans of the type used in firefighting applications by the use of positive pressure ventilation to help the firefighter both clear smoke from his path and fight the fire. Positive pressure ventilation is a firefighting technique for removing heat and smoke from a fire area within a building or the like wherein clear air is directed into the building to produce a positive pressure therein by using fans, or blowers. This technique is becoming well known in the art and involves, by way of example, positioning the fan in or near a ground floor doorway of a house having a fire therein and breaking open a window at a desirable location on the other side of the fire, such as on the second floor. The fan is operated to blow air into the house to create what is called a "positive pressure" inside the house (typically a couple of inches of water pressure) which pushes the smoke out. By the proper selection of the location of the exit opening and the direction of air flow from the fan, the clear air will flow from the doorway across the fire area to move smoke and heat away from the fire area so that it rises up and out of the house and away from the firefighters through the second floor opening provided. There are two types of blowers in use today for this type of firefighting application; namely, electric blowers and gasoline-powered blowers. Electric blowers have the disadvantage that for portable construction the higher horsepower motors are too heavy and cannot provide the high power requirements for many applications. Further, the higher current required may not be available in an emergency situation. Also, electric blowers normally are limited in speed to 3600 RPM. Gasoline-powered blowers have the disadvantages that they are noisy, heavy, and introduce deadly carbon monoxide inside the structure where the fire is located. US-A-1,407,889 discloses a blower having a fan carried by a shaft mounted for rotation and a turbine for driving the fan, the turbine including a housing having an inlet and an outlet for fluid. The invention provides a fan assembly characterised in that the assembly is for use in positive pressure ventilation in the fighting of fires and in that the turbine is water powered, the turbine housing inlet and outlet forming respectively a water supply hose connection and a water discharge hose connection both facing in a rearward direction opposite the direction of air flow produced by the fan. It is the general object of this invention to provide a water driven fan of the indicated type which is an improvement over that disclosed in said copending application. In furtherance of the general object of the invention, there is provided a portable fan driven by a water turbine capable of delivering air volume at more than 30,000 cubic feet per minute (14m³/s). The water driven fan in accordance with the invention requires no ignition, produces no exhaust, uses no electricity and eliminates the danger of sparking and the introduction of carbon monoxide into a building. Furthermore, the design in accordance with the invention can move a large amount of air in the safest way possible. Further, the design in accordance with the invention achieves a balance between efficiency and safety while offering the best performance with the lightest weight. The fan in accordance with the invention can be powered from any pumper with a tank, or from a hydrant, and can also be operated remotely from a fire truck. An actual embodiment comprises twelve polyamide fan blades, with the fan being 30 inches (0.76m) in diameter and being capable of providing sufficient pressure to ventilate several rooms simultaneously. This actual embodiment is lightweight and portable, weighing only 75 pounds (34kg) and measuring only 35 inches (0.89m) high, 35 inches (0.89m) wide and 21 inches (0.53m) long. Moreover, there is provided a water mist means which provides exposure protection for the firefighter, decreases the energy of the fire, improves the heat transfer ability of the air and replaces oxygen with water vapor in the immediate vicinity of the fire. Another feature of the invention is a novel inlet valve design whereby the inlet valve for the water is integrated into the main body of the turbine, and the valve member has a balanced action so that it is easy to open and move throughout the flow controlling positions thereof. Another feature of the invention is the arrangement of the inlet and outlet of the water flow to the turbine such that the inlet and outlet connections project in the same direction and opposite to the direction of the air flow. This arrangement allows the hoses to be positioned such that they form two thrust absorbing legs of a tripod support for the unit during operation. Another feature of the invention is the compact design of the water turbine which has a relatively small diameter. This small diameter construction reduces the weight of the unit and minimizes the blockage of air flow to the upstream side of the fan which results in a smoother and greater air flow. Another feature of the invention is the provision of a novel carrying handle design whereby a single bar is configured to provide means for use in tilting or aiming the unit easily, easy access to handle portions for carrying or wheeling the unit, and safety protection against damage to the unit. Another feature of the invention is the provision of a tilting support for she fan and turbine unit and means for locking the unit at a desired angular position about a pivotal support for the same to facilitate directing the air flow, for example, toward the center of the door opening. Another feature of the invention is the provision of a novel "built-in" flow indicator design to provide an indication to the operator of the volume of air flow of the unit. Another feature of the invention is the provision of a novel construction and arrangement of spray nozzles for introducing water into the air stream. Other features of the invention relate to design safety of the unit. To this end, there are provided both plastic blades and a plastic shroud, which prevents the possibility of sparks even if rubbing should occur. Moreover, the turbine is constructed of a non-ferrous material which also prevents the possibility of sparks. There is also disclosed a novel method and system for supplying recirculating water at high pressure in a closed loop system for the operation of a water driven fan or the like. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a rear elevational view of a water driven fan in accordance with the invention. Figure 2 is a right side elevational view of the fan shown in Figure 1. Figure 3 is a fragmentary view taken from the rear of Figure 1 and showing various details of the fan in accordance with the invention. Figure 4 is a fragmentary view showing the inlet valve of the fan in a closed position. Figure 5 is a sectional view, in elevation, of the fan shown in Figure 1 with various parts eliminated for the sake of clarity of illustration. Figure 6 is a sectional view taken on line 6-6 of Figure 5. Figure 7 is a sectional view taken on line 7-7 of Figure 5. Figure 8 is an enlarged, partially broken-away view of the area encircled in Figure 6. Figure 9 is a sectional view taken on line 9-9 of Figure 8. Figure 10 is a fragmentary view showing the air flow indicator for the fan in accordance with the invention. Figure 11 is a sectional view taken generally on line 11-11 of Figure 3. Figure 12 is a detail view of a spray nozzle. Figure 13 is a schematic view of a system for supplying water to a water driven fan. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the Drawings, the water driven fan in accordance with the invention comprises a fan and turbine unit 10 which includes a water powered turbine 12 constructed and arranged to drive a fan 14 by way of a common shaft 16. Turbine 12 comprises a runner 20 mounted on and keyed to one end of shaft 16 to rotate within the interior of a two-part turbine housing 22, which is provided with an inlet 24 and an outlet 26 for directing water into and out of housing 22. Turbine housing 22 comprises a rearwardly extending volute body 21 and a forwardly extending turbine head 23 which are connected together by bolts at mating surfaces suitably sealed by an O-ring seal. Shaft 16 is rotatably supported at a medial portion by a pair of ball bearings 30 contained in head 23 of turbine housing 22 at a specially formed bearing housing portion 25 as is shown in Figure 5. Turbine runner 20 is mounted on and keyed to the rearward end of shaft 16 by a conventional mounting arrangement shown in Figure 5. Fan 14 comprises a hub or rotor 34 mounted on and keyed to the forward end of shaft 16 by a conventional mounting arrangement shown in Figure 5. This construction and arrangement using a common shaft 16 eliminates the cost and other problems of providing a coupling between the turbine 12 and the fan 14. Fan 14 is constructed to be a strong lightweight construction and has twelve fan blades 36 mounted on hub 34 at their bases 37 so as to extend radially outwardly from the axis of shaft 16 on a pitch angle of about 45-50 degrees. The fan blades 36 are contained within a shroud 38 and are enclosed by a pair of fan guards 40 and 41 formed of an open wire-like configuration as is shown in the Drawings. Shroud 38 has a special shape whereby the air flow entering fan 14 is smoothly accelerated and the air flow leaving fan 14 is subjected to further acceleration to improve the control of the direction of the air flow. This specific construction is shown in detail in said prior-mentioned copending application. Briefly stated, the construction is such that in the direction of air flow through fan 14 the entry portion of shroud 38 is formed to converge gradually, the medial portion of shroud 38 is generally cylindrical and the exit portion of shroud 38, starting from the location where the air leaves the edges of the fan blades 36 on their outer diameter, converges in a nozzle shape. The diameter of the exit portion of shroud 38 at its downstream end is equal to or less than the outer diameter of the fan blades 36 as is shown in Figure 5. By this arrangement, the air is smoothly accelerated as it comes into fan 14 and is subjected to further acceleration by the nozzle shape for improving the directional control of the air flow. This acceleration of the air flow reduces some of the vortexes in the air flow through fan 14 and provides a smooth flow of air delivered from fan 14 so that the fan 14 becomes directional so that the firefighter can direct the air flow more accurately. A typical fan in accordance with the invention comprises a twenty (output) horsepower (15kw) water turbine 12 operating at 1750-2000 RPM and a fan 14 having a 30 inch (0.76m) diameter. An actual embodiment of the fan in accordance with the invention is capable of delivering air volume at more than 30,000 cubic feet per minute (14m³/s). Moreover, the fan is portable in that it weighs only 75 pounds (34kg). Further, the fan is very compact in that its dimensions are 35 inches (0.89m) high, 35 inches (0.89m) wide and 21 inches (0.53m) long. The lightweight construction results from the design which permits the use of a turbine 12 which is made of lightweight cast aluminum, a shroud 38 made of lightweight plastic, namely, ABS, and fan blades 36 made of a strong lightweight plastic material, namely, glass reinforced polyamide and a fan hub 34 made of cast aluminum. A feature of the invention is the compact design of water turbine 12 such that it has a minimum diameter. This minimum diameter construction results in a reduction in the weight of the unit 10 and minimizes the blockage of air flow to the upstream side of fan 14 which results in a smoother air flow. To this end, there is utilized a radial-flow reaction turbine design whereby the turbine 12 comprises a stationary outer nozzle ring 42 which is arranged to deliver a high velocity, tangential water stream to the turbine vanes of runner 20 so that the water flow strikes the turbine vanes with an impulse force which is combined with the reaction force that is contained in the turbine runner 20 itself. In effect, the design is that of a combination impulse-reaction turbine which involves only one stage whereby it can be designed to be small, compact and light in weight. To this end, nozzle ring 42 is formed on the inner face of turbine head 23 and defines a plurality of guide vanes 44 so as to receive water flow from the volute chamber 46, which is defined in body 21 to extend circumferentially around the nozzle ring 42 to communicate therewith. The construction and arrangement of turbine 12 is such that volute passage 46 is located axially behind nozzle ring 42 and runner 20, as is apparent from Figure 5. In a conventional radial turbine, the volute chamber is located radially outwardly of the runner 20. Since volute chamber 46 is behind runner 20, turbine 12 can be made of a minimal diameter so that volute chamber 46 does not take up any substantial radial space. Accordingly, as is apparent from Figure 5, the turbine housing 22 has approximately the same outer diameter as the outer diameter of the hub 34 of fan 14. By reason of this construction, it is possible to achieve good, smooth air flow plus minimal noise. Any disturbance of the inlet flow to the fan adds to the noise which is objectionable. The design of the turbine 12 is such that the water flow to cause rotation of runner 20 and the operation of the fan 14 is as follows: The water enters the upstream end 47 of volute chamber 46 from an inlet chamber adjacent the inlet 24, as is best shown in Figure 3. The water under pressure then flows through volute chamber 46 in a generally circular converging scroll-like path around the upstream end of nozzle ring 42 and the water will flow initially axially into the nozzle passages between guide vanes 44 and will then be turned radially inwardly into the turbine vanes 20' of runner 20 to cause the runner 20 to rotate. The war flows through runner 20 radially inwardly and is turned axially rearwardly to flow through the outlet 26 from which it is discharged from the unit 10. The rotation of runner 20 causes common shaft 16 to rotate thereby driving hub 34 and fan blades 36 to produce the air flow desired. A feature of the invention is the design involving a novel inlet valve which is integrated into the volute body 21 of turbine housing 22 and includes a valve member having a balanced action. Another feature is the arrangement of the inlet 24 and outlet 26 of the water flow to and from turbine 12 such that they run in the same direction and opposite to the direction of air flow. This arrangement of the inlet 24 and outlet 26 allows the fire hoses to be positioned such that they help support the unit 10 during operation. To this end, turbine inlet 24 comprises a hollow cylindrical portion 50 of turbine body 21 that extends along an axis parallel to the axis of shaft 16 in a rearward direction, i.e., a direction opposite to the direction of air delivery from the fan 10. Portion 50 has a strainer 51 located in a counterbore in its end. A female hose coupling 52 is rotatably attached on the end of portion 50 and is provided with internal threads for connection to the male coupling of a supply hose 53 shown in connected condition in Figures 1 and 2. Turbine body 21 defines an inlet chamber 54 (Figures 3 and 4) for receiving water under pressure delivered to the inlet coupling 52 by way of the supply hose 53 which is connected to a suitable pressurized water supply. A flow control inlet valve means 60 is mounted in the turbine body 21 for controlling the flow of water from the inlet chamber 54 to the upstream end 47 of volute chamber 46. The flow control inlet valve means 60 includes a valve seat 62 at the upstream end 47 of volute chamber 46, a throttle valve member 64 cooperable with valve seat 62 for controlling flow therepast and means for mounting valve member 64 for movement toward and away from the valve seat 62. The mounting means for valve member 64 includes a cover 66 mounted on the turbine body 21, a valve stem 68 threadedly mounted in cover 66 and having valve member 64 mounted on the lower end thereof for movement therewith by means of a nut 69. A handle 63 is secured on the upper end of valve stem 68. Valve member 64 has a cylindrical recess 65 formed in the upstream side thereof and cover 66 has a plug portion 67 extending into inlet chamber 54 and sealingly received within recess 65, the seal being provided by means of an O-ring seal carried by plug portion 67. This design minimizes the pressure area on the upstream side of valve member 64 to thereby provide a balancing of the pressures on the upstream and downstream sides of valve member 64. Thus, the operator of the fan unit 10 can turn handle 63 and move valve member 64 very easily to open valve means 60 and set the same at the desired flow control positions. It is particularly advantageous to be able to open the valve means 60 easily and this is achieved by means of the above-described balanced arrangement. The turbine outlet 26 comprises a hollow cylindrical portion 27 of the turbine body 21 that extends along an axis parallel to and in alignment with the axis of shaft 16 and parallel to the axis of the turbine inlet cylindrical portion 50 as is shown in Figure 5. The hollow cylindrical portion 27 also extends in the same direction as the inlet portion 50 i.e., rearwardly. The rearward end of the outlet cylindrical portion 27 has external male threads formed thereon to provide a coupling for connection to a female coupling of a return hose 55. The above-described arrangement whereby the inlet and outlet hose connections extend rearwardly from the unit 10 provides a very advantageous design whereby the supply hose 53 and the return hose 55 can be connected to the unit 10 to extend rearwardly therefrom. The arrangement permits the operator to put the unit 10 as close to a doorway was possible during use because there is no need to leave clearance for the hoses 53 and 55. Furthermore, firefighting hoses are typically 2 1/2 inches (6.35cm) in diameter and will not bend on a very sharp radius, particularly when they are stiff, and instead will "kink" if they are bent too sharply. Furthermore, with the hoses 53 and 55 extending rearwardly from the unit 10, they can be placed on the ground to, in effect, act like a tripod support. In other words, one fire hose is bent to extend away from turbine 12 outwardly in one direction and the other hose is bent to extend away from turbine 12 in a diverging direction whereby the hoses themselves act like a supporting tripod to take up the reaction force (thrust) that is developed from the unit 10, i.e., the reaction force that wants to move the unit 10 rearwardly. A feature of the invention is the provision of a novel construction and arrangement of nozzles for introducing a spray of water into the air stream so that a water mist can be delivered to a fire. Such means comprises three spray nozzles 70 mounted at the periphery of turbine head 23 in a circumferentially equally spaced relationship, as is best shown in Figure 6. The nozzles 70 are arranged to inject a small spray of water behind the fan blades 37 whereby a mist of water can be directed to the fire area by the firefighter during the fighting of a fire by positive pressure ventilation. Nozzles 70 each have an orifice opening 71 configured to dispense a flat, diverging (V-shaped) water spray and are oriented to direct these water sprays in planes extending transversely across a wide portion of the path of rotation of fan blades 36. There is provided means for supplying water to said spray nozzles, such means comprising a flow control valve means 72 for controlling the flow of water to the spray nozzles 70 and flow passage means for supplying water from the inlet chamber 54 to the upstream end of the inlet passage 73 of each spray nozzle 70. Referring particularly to Figures 6, 8 and 9, the valve means 72 comprises a rising stem plug valve 74 having a valve member 76 cooperable with a valve seat 78 which is in communication, at its upstream side, with the inlet valve chamber 54. From the downstream side of the valve seat 78 there is provided a horizontal passageway 80 which communicates at its down-stream end with a short vertical passageway 82, which, in turn, communicates at its downstream end with a small, flat horizontally extending passageway 84. Passageway 84 communicates, at a small rectangular port with an annular passageway 86 between the body 21 and head 23 of the turbine housing 22. As is best shown in Figure 9, each of the spray nozzles 70 is threadedly mounted in the head 23 in a bore 90 which communicates at its inner end with a part of annular passageway 86. The inlet passages 73 of each of the spray nozzles 70 communicate, at their upstream end, with an associated bore 90. In order to inject a water spray behind the fan blades 36, the operator simply opens valve means 72. Valve means 72 is opened by turning the valve handle 75 attached on the outer end of a valve stem 77 on which valve member 76 is provided. This causes valve member 76 to move away from valve seat 78 so that water can flow from inlet chamber 54 therepast into passageway 80. The water flows sequentially through passageway 80, passageway 82 and passageway 84 into annular passageway 86. From passageway 86 the water flows into each of the bores 90 and each nozzle inlet passage 73 and is dispensed through the associated orifice openings 71 to be directed into the air stream at a location behind fan blades 36. The fan 14 directs the three water sprays as a fine mist along with the air flow delivered thereby. A feature of the invention is the provision of a novel frame which provides a support for the unit 10 and means for locking the unit 10 at a desired angular position about a pivotal mounting for the same on the novel frame. To this end, there is provided a frame 92 which is made of a one-piece tubular construction including a pair of side arms 93 which are joined at their lower ends by a cross member 95. The side arms 93 have a generally upright straight portion extending from the upper end thereof to join a curved portion at the middle thereof and a bottom portion extending from the curved portion along the ground. At bores in their upper ends, the side arms 93 rotatably support a pair of axles 91 which are located to extend on a transverse horizontal axis and are received in hubs 96 formed on the turbine body 21 at diametrically opposed locations. The axles 91 are formed by the shank portion of mounting bolts 97 the threaded ends 94 of which are fixedly secured in an associated hub 96. Side arms 93 have a transversely extending axle 98 extending through the curved portions thereof. At the outer ends of axle 98 there are mounted a pair of wheels 100 which are located on the outside of the side arms 93. Frame 92 thus has a pair of side arms 93 which extend rearwardly from the top end thereof at an angle to a curved portion and forwardly from the curved portion along the ground to cross member 95 to thereby provide stable support for unit 10. The wheels 100 provide a rolling support for unit 10 when it is desired to move the unit 10 along the ground. In accordance with a feature of the invention, the transverse axis of the upper axles 91 is arranged to extend through the center of gravity of the fan and turbine unit 10. This provides for stability during use and transport of unit 10. There is provided means for releasably locking unit 10 in a plurality of angular positions about the pivotal axis thereof provided by axles 91. To this end, body 21 has mounted thereon, by means of a pair of mounting bolts 102, a guide plate 104 having an arcuate slot 106 therein extending on an arc centered on the pivotal axis of unit 10 provided by axles 91. Plate 104 is positioned adjacent the upper portion of one of the side arms 93 as is shown in Figures 1, 3 and 11. A releasable locking means is mounted on one side arm 93 adjacent guide plate 104 and comprises a carriage bolt 108 received at its straight sided portion in arcuate slot 106. The shank portion of bolt 108 extends through a horizontal hole in side arm 93 and has its threaded end engaged with a handle 110. The parts are arranged so that handle 110 can be rotated to tighten plate member 104 in a frictionally secured position against the side arm 93 when desired. In this manner, it is possible to pivot unit 10 about its pivotal axis and lock the same in any desired angular position limited only by the cooperation between the bolt 108 and the slot 106 of guide plate 104. In Figure 11, unit 10 is shown in its vertical position. However, it will be apparent that unit 10 can be pivoted in a counterclockwise direction, as viewed in Figure 11, to various upwardly facing positions, such as shown in Figure 13, for example. When the angular position is selected, unit 10 can be locked therein by turning handle 110 to frictionally secure side arm 93 of frame 92 and guide plate 104 together. As shown in Figure 3, suitable friction washers are positioned between handle 110 and side arm 93 and between guide plate 104 and side arm 93. Another feature of the invention is the provision of a novel carrying handle design whereby a single bar is configured like a handlebar to provide means for tilting or aiming the unit 10 easily, with easy access to handle portions for carrying or wheeling unit 10, and means providing safety protection against damage to the unit 10. To this end, a handle 112 is made of a single piece construction and is connected by bolts to the shroud 38 at a pair of end portions 114 which extend rearwardly from shroud 38 at circumferentially spaced apart locations thereof. Each end portion 114 has a hand grip 115 thereon for use in carrying unit 10. The single-piece handle 112 includes a second portion 116 which joins end portions 114 and extends in a radial plane spaced rearwardly from shroud 38. The top of portion 116 extends on an arc having a portion radially outwardly of shroud 38. The radial plane wherein portion 116 is located is positioned to be rearwardly beyond the turbine body 21 whereby handle 112 protects turbine 12 if unit 10 should fall over rearwardly. Another feature of the invention is the provision of a novel "built-in" air flow indicator to provide a visual indication to the operator of the volume of free air flow being delivered by fan 14. To this end, there is provided a flow indicator 120 of the type disclosed in detail in U.S. Patent No. 4,715,327. The flow indicator 70 is mounted on the turbine body 21 to extend horizontally by means of a mounting bolt 119 which cooperates with a mounting bracket 123 to secure an inlet end bonnet 121 to turbine body 21. Bonnet 121 defines an inlet chamber 122 which has an inlet port in flow communication with a passage 124 in body 21 leading to a part of volute chamber 46 and having a ranging orifice 125 therein. A transparent tube 127 extends horizontally from inlet bonnet 121 and has its downstream end received in and sealed within a bore 117 in the side of outlet 26 communicating with the outlet flow from turbine 12. The upstream end of tube 127 is also suitably sealed in inlet bonnet 121 as is shown in Figure 10. Transparent tube 127 provides a window through which the water flowing from volute chamber 46 to the outlet 26 can be visually observed. The flow indicator 120 comprises means for indicating the volume of the free air flow delivered by fan 14. Such means comprises an elongated coil spring 128 contained within tube 127 and having one end secured to a pin 129 fastened at the inlet end of tube 127 and having a free end adapted to move within tube 127 as spring 128 expands and contracts between a collapsed condition and a fully extended position shown in Figure 10. Coil spring 128 is constructed with a selected spring rate whereby spring 128 can be expanded a substantial distance and an amount that is corrolated with the pressure differential between the inlet and outlet of flow indicator 120 which corresponds to the pressure differential across tubine 12 and the free air flow delivered by fan 14. The air flow indicator means also comprises a ball 130 which is captured within the interior of the coils of spring 128. To this end, spring 128 has the coils at its free end wound into a tapered configuration to thereby capture the ball 130. The parts are arranged so that ball 80 assumes a set position within the free end of spring 128 in response to the drag force thereon provided by the flow of water through tube 127 from the inlet to the outlet ends thereof. Ball 130 is colored yellow, (or another bright color) so as to be clearly visible and is smaller in diameter than the inner diameter of tube 127. Tube 127, spring 128, and ball 130 are constructed and arranged so that the water flow through the tube 127 from the inlet to the outlet ends thereof passes around ball 130 resulting in a drag force being applied to ball 130 causing it to move toward the outlet end of tube 127. This movement of ball 130 causes spring 128 to expand. The arrangement is such that ball 130 will assume a position which is indicative of the pressure differential between the inlet and outlet of tube 127 which corresponds to the volume of water flow through the turbine 12 and the rate of rotation of the turbine runner 20 and, therefore, the position of ball 30 corresponds to the rate of rotation of fan blades 36 and the volume of free air being delivered by the fan 14. A scale 140 is mounted on body 21 adjacent tube 127 and is provided with indicia to indicate the volume of air flow in CFM (cubic feet per minute; 1 m³/s = 2120 CFM) as is shown in Figure 10. Ranging orifice 125 is sized so that ball 130 will move within tube 127 and across the indicia on scale 140 during the normal range of operation of turbine 12. Another feature of the invention is the provision of a closed loop system for supplying water at high pressure for the operation of the turbine and fan unit 10 which system can be operated by a novel method. An object of the system and method is to minimize the heat buildup of the water circulating in the closed loop supply system. A feature of this closed loop system is that the water supply to the unit 10 is a relatively small amount and said supply can be contained in the water tank provided on a typical fire truck. Further, by the use of a recirculating conduit means cold water is added to the recirculating loop from the supply tank to minimize the rate at which the temperature rise of the water circulating in the closed loop occurs. The system is disclosed in Figure 13 and comprises a supply hose 53 connected at its downsteam end to the inlet 24 of turbine 12, a return hose 55 connected at its upstream end to the outlet 26 of turbine 12. The high pressure water supply includes a high pressure pump 150 having a discharge 152 and a suction 154. By way of example, pump 150 may comprise a midship fire truck pump manufactured by Hale Fire Pump Company and capable of delivering from 750-2000 gallons per minute (3410 to 9090 litres per minute) at pressures up to typically 300 PSI (about 2 x 10³ kPa) while being driven from the engine of a typical fire truck 200. There is also provided a first conduit means 156 for delivering water from discharge 152 of pump 150 to a discharge fitting 158, which has the upstream end of the supply hose 53 coupled thereto. A pump discharge valve 160 is connected in the conduit means 156 to control flow therethrough. Discharge valve 160 is typically a ball valve which has some throttling capability. The system includes a second conduit means 162 for delivering water from the downsteam end of return hose 55 to the suction of pump 150. Conduit means 162 has two branches,one of which has a pump inlet valve 165 connected therein and terminates at a suction fitting 164 coupled to return hose 55. The other branch of conduit means 162 terminates at a suction tube cap 167 and has a butterfly valve 163 connected therein to control flow therethrough. Valve 165 is typically a ball valve. Pump 150 and the conduits 156 and 162 are typically made as all part of the same casting and are mounted on the fire truck 200 adjacent to a supply tank 170 on the fire truck 200 and known in the art as a "booster tank". A third conduit means 172 is connected between supply tank 170 and conduit means 162 and has a tank valve 174 connected therein for controlling flow from tank 170 to a portion of conduit means 162 downsteam of valves 163 and 165. A fourth conduit means 180 is connected between conduit means 156 and the supply tank 170 and has valve 182 connected therein for controlling flow therethrough. The above-described arrangement of pump 150 and conduit means 156, 162 and 180 is provided on many fire trucks; however, they are used in a conventional way to supply water to fire hoses, draw water from other fire trucks or hydrants, relay water from one fire truck to another, etc. and have not been used to drive water driven devices like unit 10. In accordance with the novel method and system of the invention, the system shown in Figure 13 is operated as follows. The first thing the firefighters do upon the arrival at a fire scene with a fire truck 200 having its tank 170 filled with a volume of water is to position the unit 10 and hook up the supply hose 53 and return hose 55 between the inlet 24 and outlet 26 of the unit 10 and the discharge fitting 158 and suction fitting 163 in the arrangement shown in Figure 13. During this hook-up procedure all the valves 160, 163, 165, 174 and 182 on the fire truck 200 are positioned in their closed position. In the use of the system with a fan and turbine unit 10, the inlet valve 60 on the unit 10 is initially positioned in the closed position. In this case, the valves 160, 165, 174 and 182 are then opened in any desired sequence. Preferably valve 165 should be opened first to prevent excessive pressure buildup in the return line. Then, when pump 150 is brought to an operating condition and the inlet valve 60 of unit 10 is opened, the water will flow through a closed loop system as shown by the arrows in Figure 13. In some cases it may be desirable to open the pump discharge valve 160 last and use it to achieve a throttling control of the water flow. This would be achieved in combination with the throttle of the fire truck engine that drives pump 150 and is conventional procedure used by firefighters. The system will now operate in a novel manner to provide a recirculating closed loop water supply to the turbine 12 and to operate unit 10 with a quantity of water such as is carried by tank 170 of a conventional fire truck. In addition, by reason of the secondary recirculating flow of water through conduit means 180 from the discharge 152 of the pump 160 back to the supply tank 170, low temperature water will be continually added to the closed loop through conduit means 172 and tank valve 174. This secondary recirculating flow serves to moderate the rate of temperature rise of the water flowing through the closed loop system during operation to a rate which will prevent damage to the pump 150, the turbine 14 and the other components in the closed loop system. It is to be noted that the system shown in Figure 13 is applicable to various types of water-powered devices other than the turbine and fan unit 10, such as for example, other types of water turbine or water motor driven fire-fighting and rescue equipment.

Claims: A fan assembly for use in positive pressure ventilation, having a fan (14) carried by a shaft (16) mounted for rotation, and a turbine (12) for driving the fan (14), the turbine (12) including a housing having an inlet (24) and an outlet (26) for fluid, characterised in that the assembly is for use in positive pressure ventilation in the fighting of fires and in that the turbine is water powered, the turbine housing inlet (24) and outlet (26) forming respectively a water supply hose connection and a water discharge hose connection both facing in a rearward direction opposite the direction of air flow produced by the fan. A fan assembly according to claim 1 characterised in that the turbine housing defines an inlet chamber (54) for receiving water under pressure from the inlet (24) to drive the turbine, and a volute chamber (46) communicates with said inlet chamber (54) from which volute chamber water is supplied to the turbine around the axis thereof. A fan assembly according to claim 2, characterised by a flow control valve means (60) mounted in said turbine housing for controlling the flow of water from said inlet chamber to said volute chamber. A fan assembly according to claim 3, wherein said flow control valve includes a valve seat (62) at the downstream end of the inlet chamber (54), a valve member (64) cooperable with said valve seat for controlling flow therepast, a cover (66) mounted on the turbine housing (22), and a valve stem (68) threadedly mounted in the cover (66), the valve member (64) being mounted on the end of said valve stem (68) for movement therewith, the valve member (64) having a recess (65) formed in the upstream side thereof, and the cover (66) having a plug portion (67) extending into the inlet chamber (54) and sealingly received within the recess (65) in the valve member (64). A fan assembly according to any of the preceding claims, wherein the turbine includes a runner (20) mounted for rotation about its axis having a set of radial flow turbine vanes (20') facing rearwardly of the runner plane, and the volute chamber (46) lies in a region axially behind said turbine vanes. A fan assembly according to claim 2, wherein the fan (14) includes a central hub (34) from which fan blades (36) extend radially outwardly, and the volute chamber (46) has an outer diameter approximately equal to or less than the diameter of the hub (34) of the fan. A fan assembly according to any of the preceding claims, characterised by a plurality of spray nozzles (70) in said housing constructed and arranged to deliver a small spray of water behind said fan blades whereby a mist of water can be directed to the fire area by the firefighter during the fighting of the fire by positive pressure ventilation, and means (86) for supplying water to said spray nozzles. A fan assembly according to any preceding claim, characterised by a frame (92) supporting said fan assembly and having wheel means (100) mounted thereon to provide a rolling support for said unit. A fan assembly according to any preceding claim, characterised by a frame (92) supporting the fan assembly, means mounting the unit on the frame to pivot about a transverse axis to various angular positions, and handle means (112) secured to said unit for directing the position of said frame and for tilting said unit to a desired angular position. A fan assembly according to any preceding claim, characterised by flow indicator means (120) for indicating the flow rate of water through the unit and thereby indicating the volume of the air flow delivered by the fan. A fan assembly according to any preceding claim wherein the fan assembly includes a housing (38) extending around the outer edges of the fan blades (36), said housing (38) being constructed and arranged to provide a converging entry portion upstream of the fan blades for accelerating the flow of air entering the fan (14) and a converging exit portion downstream of the fan blades for accelerating the flow of air exiting the fan blades (36). A fan assembly according to claim 1, characterised by a means for supplying water at high pressure to the fan assembly (10), by means of a system including a high pressure pump (154) having a discharge and a suction, a supply tank (170) containing a volume of water, first conduit means (156, 53) for delivering water from said pump discharge (152) to the fan assembly (10), second conduit means (55, 162) for delivering water from the fan assembly (10) to a suction of said pump, third conduit means (172) connected between the said supply tank (170) and said second conduit means (162) for delivering water from said tank to said pump section, and fourth conduit means (180) connected between said first conduit (152) means and said supply tank (170) for delivering water from said first conduit means to said supply tank.

Inventors: EBERHARDT HARRY ALFRED, TESKE RICHARD E, EBERHARDT, HARRY ALFRED, TESKE, RICHARD E.
Applicants: HALE FIRE PUMP CO, HALE FIRE PUMP COMPANY
Application year: 1990
Main classification: A62C3
IPC codes: F04D27, F04D25, A62C3, F03B13