Abstract:
A fire fighting pump and operation thereof and a fire fighting system and a fire engine, wherein the pump includes a housing, a motor mounted inside the housing and two or more stages of series-connected impeller assemblies. A water inlet is provided on the housing between the motor and the impeller assemblies. The impeller assemblies are mounted on the impeller shaft coaxially and in series with each other. The impeller shaft is fixed on the motor shaft or is coaxial with the latter. The impeller assembly includes a thruster, an impeller, an end cover and a retaining ring on the periphery of the thruster and the impeller, and those four elements are installed in turn. Several first blades are provided in the thruster and several second blades which correspond with the first blades in amount and location are provided in the impeller.

Description:
BACKGROUND TECHNOLOGY 
       [0001]    (a) Field of the Invention 
         [0002]    This invention involves in a kind of water pump and its operating methods, especially in a kind of submersible water pump for the use of forest fire fighting and its operating methods. 
         [0003]    (b) Description of the Prior Art 
         [0004]    For mountainous landfomms, since forest area has complicated landforms, steep and difficult terrains, luxuriant bushes and grasses and rich vegetations, once there is a forest fire that is strong and spreads quickly, it is very difficult and dangerous to put out the fire with wind extinguishing machines, No. 2 tools, extinguishing bombs and back-type extinguishing gun  34 , and especially, it is to put out tree top fire, mountain top fire, high strong fire line, it is impossible to use ordinary tools mentioned above to put out such fire. 
         [0005]    Water can put out the fire, furthermore, it is a kind of the most ordinary, effective and cheapest natural extinguishing agent. So it is the first choice to use water to put out the forest fire in many forest-developed countries. Some places with relatively fine economic conditions have taken the lead to use water pump, water vehicle and back-type water gun  34  to extinguish the fire. But fire fighting water source is restricted by high and steep fire site and relatively far distance. Since back-type water gun  34  is restricted by heavy load and no continuous water supply at the fire site, so it is usually to use it to clear up the fire site, it is hard to use it for effectively controlling the fire line, especially for controlling a high strength fire line. Water vehicle has a high cost and is limited by landform, and it is unsuitable for some places where are inaccessible for vehicles. 
         [0006]    Existing fire fighting pumps are usually driven by motors by means of belt wheels, with small lifts. In order to realize a certain high lift, it is usually to place a water pump at a certain height to gradually pump water to the required height through series-mounted multiple-stage water pumps. Currently, such application is featured by “multiple-stage connection and infinite water supply” of the water pump, on one hand, it always leads to a dead pump due to empty water hose  33  since there is unbalanced pumping water pressure between pumps, so it usually can neither transmit water to the fire line and nor bring water distinguishing effect into full play, on other hand, it increases cost and transportation difficulties, and especially, when it needs to install several water pumps at different heights and places, installation time is long. For some places with a complicated landform, it may be impossible to install them. Because of long installation time, extinguishing time will be extended and extinguishing operation will become more difficult. 
         [0007]    When forest fire occurs at forest mountains, since the mountain is high and steep, road is not accessible and water source is difficult, to put out a forest fire with water doesn&#39;t need a big water flow, but it needs to transmit water with long distance and high lift. Therefore, forest fire fighting pump should introduce equipments with relatively low water flow, relatively high lift, relatively light weight and relatively small volume, so as to facilitate carrying and operation at hill area, and it shall not use fire fighting pump equipments for urban use with relatively big water flow, relatively low lift and relative big size and heavy weight. 
         [0008]    First, existing fire fighting pump lacks full knowledge on forest fire fighting with water, it doesn&#39;t get ride of the wrong field, which forest fire fighting with water also needs a big water flow, high water pressure and long spraying distance; second, study on application idea and pattern of forest fire fighting with water is not sufficient. Forest fire spreading features decide fire line&#39;s dynamic feature, thus leading fire area to continue expanding and fire line to extend. Therefore, it lacks an application pattern of effective “dividing forces for encircling and making breakthroughs at several points”. Third, we cannot fetch water everywhere. Under specific forest conditions, if we want to put out a fire with water, we should try to get, transmit and guarantee a water source first. The current water pump cannot meet the need of small-caliber water hose  33  for high lift, long distance, high pressure-proof, fast laying and flexible water distribution to put out a forest fire. 
         [0009]    Now, there is a kind of submersible water pump for deep well operation, e.g. patent number 01271640.5, a submersible water pump includes a housing, a motor fitted inside the housing, and a bush in which multiple-stage impellers are installed. On the top of the motor is an end cover while a bearing seat is on its low part. Impellers are installed on the impeller shaft in series. Impeller shaft is connected with the motor shaft by means of a coupling while a water inlet is provided on the housing between motor and impellers. As compared with a submersible water pump driven by a belt wheel of a motor, a submersible water pump of such structure is featured by small volume, big pressure, high lift and simple installation. Since the existing submersible water pump can only use the centrifugal force of the multiple-stage impellers to increase the pressure, so the increased pressure is limited and lift cannot meet the need of fire fighting, therefore, it is usually used for deep well operation, it is not used as a fire fighting pump. The operating methods of current water pump is that only the impellers rotate, but without a thruster, so such kind operating methods of existing submersible water pump cannot form a helical separation propelling mode to her increase the water pressure, as a result, the lift and water transmitting distance cannot meet the need for fire fighting, furthermore, the existing submersible water pump is not yet used for fire fighting, and especially for forest fire fighting. 
       SUMMARY OF THE INVENTION 
     Invention Contents 
       [0010]    The first purpose of this invention aims at providing a kind of fire fighting pump to meet fire fighting need through heightening the lift by means of increasing pressure between the impeller assemblies of the submersible water pump. 
         [0011]    The second purpose of this invention aims at providing operating methods of a fire fighting pump with long distance, high lift and strong pressure resistance. 
         [0012]    To realize this invention is a kind of fire fighting pump that includes a pump housing, a motor installed inside the pump housing and series-mounted two-stage or over two-stage impeller assemblies installed inside the cylindrical cavity of the pump housing. Pump housing is equipped with a water inlet between the motor and the impeller assemblies that are coaxially mounted on the impeller shaft or with the motor shaft. Impeller shaft is fixed on the motor shaft. The impeller assembly includes a thruster, impellers, an end cover and retaining rings. At the center of the end cover is equipped with the first vent. The thruster includes the central shaft, 3 or more than 3 first blades, the first hub and the second hub, the first blade is fitted between the first hub and the second hub; 3 or more than 3 first division grooves are formed among the first hub, first blades and the second hub. Inside the central shaft is provided with a second vent that matches the impeller shaft. The thruster is fixed on the impeller shaft through the second vent. Impellers include the second blades whose number is the same as those of the first blades, the third hub and the fourth hub. The position of the second blade corresponds with position of the first blade. The second blades are placed between the third hub and the fourth hub. The second division grooves are formed among the third hub, the second blades and the fourth hub, whose number is the same as those of the first division grooves. The third vent is provided at the center of the impellers, which matches with the central shaft of the thruster. The third hub of the impellers is supported on the second hub of the thruster. The central shaft of the thruster is coupled inside the third vent of the impellers. The retaining rings are mounted on the outer ring of the impellers and thruster. The end cover is fitted on the impellers. A sealed water flow passage is formed among the end cover&#39;s vent, the first division groove of the thruster, the second division groove of the impellers and the retaining ring. The end cover and thruster are installed together between the two neighboring impeller assemblies. A sealed water flow passage is formed between the impeller assemblies. The major difference between this technical plan and the existing submersible water pump for deep well operation lies in the structure of the impeller assemblies. During pumping water, impeller shaft rotates together with the motor shaft so as to drive thruster fixed on the impeller shaft to rotate, while the impeller shaft drives the thruster fixed on the impeller shaft to rotate. Impellers of the impeller assemblies, retaining rings and end cover rotate irregularly under the action of the thruster, thus forming a helical separation propelling mode, increasing water pressure, and making water supply distance longer, lift high and volume small. So it is unnecessary to install a fire fighting pump at a certain height, it is only to pull the water hose to the needed position. Install is fast, convenient, not limited by landform and has a wide applicable field, so it can meet fire fighting need. 
         [0013]    As a modification, the first positioning ring is equipped in the direction of the first hub reverse to the outer periphery along the small end of thruster&#39;s first hub. The first positioning ring is fitted inside the first vent of the end cover and matches the first vent, thus facilitating the assembly. 
         [0014]    As a modification, the second positioning ring is fitted in the direction of small end of the fourth hub facing the big end of the outer periphery along the fourth hub of the impellers. The first step is fitted on the second positioning ring. The inner periphery of the retaining ring matches the outer periphery of the first step, thus facilitating the assembly and sealing the water flow passage. 
         [0015]    As a modification, the end cover is equipped with the third step and the fourth step. The outer periphery of the third step matches the inner periphery of the retaining ring; the outer periphery of the fourth step matches the inner periphery of the second positioning ring, thus facilitating the assembly and sealing the water flow passage. 
         [0016]    As a modification, the maximum outer diameters of the end cover, retaining ring and the second positioning ring are equal, thus facilitating to put them into the pump housing. 
         [0017]    As a modification, the stage of the described impeller assemblies is 30˜74, and the number of thruster&#39;s first blades is 3˜12, thus making single pump&#39;s water transmitting distance/lift reach 2500 m/100 m˜1500 m/200 m. 
         [0018]    The first hub and the second hub of the thruster are of an open and diplex umbrella type. The first hub is in parallel with the second hub. The third hub and the fourth hub of the impellers are of an open and diplex umbrella type, and the third hub is in parallel with the fourth hub. Such shape is conducive to increasing water pressure. A rubber washer is fitted between the third vent of impellers and the central shaft of the thruster, which can reduce friction and mutual collision between the central shaft of thruster and impellers, thus enabling the fire fighting pump to be endurable. 
         [0019]    As a modification, the first hub&#39;s maximum outer diameter is greater than the second hub&#39;s maximum outer diameter, the fourth hub&#39;s maximum outer diameter is greater than the third hub&#39;s maximum outer diameter, and the maximum outer diameters of the second hub and the third hub are basically the same, so it is convenient for smooth water flow, thus increasing fire fighting pump&#39;s water transmitting distance and lift. The helical direction of the first blade is reverse to that of the second blade. 
         [0020]    As a further modification, pump housing is cylindrical for convenience of production. Thruster, impellers, end cover and retaining rings are made of stainless steel. So it improves wear resistance and tightness, and has a low requirement for water quality. Not like plastic material, stainless steel material will not produce deformation during high speed rotation, so pump body can be laterally, obliquely and vertically placed, and it suits various water qualities. 
         [0021]    It is a kind of operating method of a fire fighting pump. Fire fighting pump includes a pump housing, a motor mounted inside the pump housing, and 2-stage or over 2-stage series-mounted impeller assemblies. Pump housing between the motor and impeller assemblies is equipped with a water inlet. Impeller assemblies are coaxially series-mounted on the impeller shaft. Impeller shaft is fixed on the motor shaft or coaxial with the motor shaft. Impeller assembly includes the thruster, impellers and end cover. Around the thruster and impellers are equipped with retaining rings. The first blades are provided on the thruster. The second blades are provided on the impellers, whose number is the same as that of the first blades and with the corresponding positions. Thruster is fixed on the impeller shaft. Impellers are coupled on the impeller shaft, and end cover passes through the impeller shaft. During pumping water, operating process includes that impeller shaft rotates together with the motor shaft. Impeller shaft drives the thruster fixed on the impeller shaft to rotate. Impellers, retaining ring and end cover of the impeller assemblies rotate irregularly under the action of the thruster. Operating way of a fire fighting pump forms a helical separation propelling mode that increases the water pressure, makes water supply distance longer and lift high, so it can meet fire fighting need. 
         [0022]    Effective result of this invention derives from introduction of submersible water pump structure for deep well operation, increase of a thruster, so it forms a helical separation propelling mode and increases propelling water pressure, thus making water supply distance longer, lift high and easy water suction. Single pump water transmitting distance/lift can reach 2500 m/50 m˜1000 m/200 m while water pump&#39;s effective water supply flow/lift can reach 6.0 m/50 m˜3.0 m/2000 m per hour. It features small volume, quick and easy installation, no landform restriction and wide application field. Thruster and impellers are made of stainless steel material, so it increases its wear and tightness. It has a low water quality requirement. Not like plastic material, stainless steel material will not produce deformation during high speed rotation, so pump body can be laterally, obliquely and vertically placed, and it suits various water qualities. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a schematic one for the submersible water pump of this invention to connect with outer equipments. 
           [0024]      FIG. 2  is a schematic one for impeller assembly structure of the submersible water pump of this invention, which is cut along the central position of the assembly. 
           [0025]      FIG. 3  is a dimensional resolution schematic one of this invention for an impeller assembly that is turned by 180°. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Concrete Implementation Mode 
       [0026]    As shown in  FIG. 1  to  FIG. 3 , a kind of fire fighting pump  29  includes a cylindrical stainless steel pump housing  1 , a motor (not shown) fitted inside the pump housing  1  and 52-stage series-mounted impellers assemblies  30 . A water inlet  31  is provided on pump housing  1  between the motor and impeller assembly  30  that is coaxially series-mounted on the impeller shaft  2 . The impeller shaft  2  is an external hexagonal metal shaft and fixed on motor shaft (not shown) by means of a coupling and coaxially interacts with the motor shaft. 
         [0027]    Impeller assembly  30  includes stainless steel end cover  3 , stainless steel thruster  4 , stainless steel impeller  5  and stainless steel retaining ring  6 . 
         [0028]    Thruster  4  includes central shaft  7 ,  3  first blades  8 , the first hub  9  and the second hub  10 . Thruster  4 &#39;s first hub  9  and second hub  10  are of open diplex umbrella type. The first hub  9  and the second hub  10  are in parallel. The first hub  9 &#39;s maximum outer diameter is greater than the second hub  10 &#39;s maximum outer diameter. The first blade  8  is placed between the first hub  9  and the second hub  10 . Three first division grooves  11  are formed among the first hub  9 , the first blade  8  and the second hub  10 . The second vent  12  that matches impeller shaft  2  is fitted on the central shaft  7 . The second vent  12  is of an internal hexagonal type. Thruster  4  is fixed on impeller shaft  2  via the second vent  12 . The first positioning ring  13  is provided in the direction reverse to the first hub  9  along the outer periphery of small end of thruster  4 &#39;s first hub  9 . 
         [0029]    Impeller  5  includes the second blade  14  that is the same as the first blade  8 . Positions of the third hub  15 , the fourth hub  16  and the second blade  14  correspond to the position of the first blade  8 . Impellers  5 &#39;s third hub  15  and fourth hub  16  are of an open and diplex umbrella type. The third hub  15  and the fourth hub  16  are in parallel. Third hub  15 &#39;s maximum outer diameter is smaller than the maximum outer diameter of the fourth hub  16 . The second blade  14  is placed between the third hub  15  and the fourth hub  16 . The second division groove  17  is formed among the third hub  15 , the second blade  14  and the fourth hub  16 , which is the same as the first division groove  11 . The third vent  18  is provided in the center of the impeller, which matches the central shaft  7  of the thruster  4 . A rubber washer  19  is fixed inside the third vent  18  of the impeller  5 . The second positioning ring  20  is fitted in the direction of small end of the fourth hub  16  facing the big end of the outer periphery along the fourth hub of the impeller. The first step  21  is provided on the second positioning ring  20 . The inner periphery of the retaining ring  6  matches the outer periphery of the first step  21 . 
         [0030]    The first vent  22  is provided on the center of the end cover  3 . The first positioning ring  13  is fitted inside the first vent  22  of the end cover  3 , and matches the first vent  22 . End cover  3  is equipped with the third step  23  and the fourth step  24 . The outer periphery of the third step  23  matches the inner periphery of the retaining ring  6  wile the outer periphery of the fourth step  24  matches the inner periphery of the second positioning ring  20 . 
         [0031]    Maximum outer diameters of the end cover  3  while retaining ring  6  and the second positioning ring  20  are equal. Maximum outer diameters of the second hub  10  and the third hub  15  are basically the same. The helical direction of the first blade  8  is reverse to that of the second blade  14 . 
         [0032]    Rubber washer  19  is fixed inside the third vent of the impeller. The central shaft  7  of the thruster  4  is mounted onto the rubber washer  19  of impeller  5 . The third hub  15  of impeller  5  is supported on the second hub  10  of thruster  4 . Retaining ring  6  is fitted on the outer periphery of impeller  5  and thruster  4 , and matches the first step  21  of impeller  5 . Central shaft  7  of thruster  4  is fixed on impeller shaft  2 . Impeller  5  is coupled on the central shaft  7  of thruster  4  by means of rubber washer  19 . Thruster  4  of neighboring impeller assembly  30  is mounted together with end cover  3 . Outer periphery of the fourth step  24  of end cover  3  matches inner periphery of the second positioning ring  20  of impeller  5 . A sealed water flow passage is formed among the end cover  3 &#39;s vent, thruster  4 &#39;s first division groove  11 , impeller  5 &#39;s second division groove  17  and retaining ring  6  while a sealed water flow passage is formed between impeller assemblies  30 . 
         [0033]    Submersible water pump&#39;s motor connects with generator  32 . One end of impeller assembly  30  of the submersible water pump connects with water hose  33  that connects with water gun  34 . Number of the first blades is 3. Submersible water pump introduces a 52-stage impeller assembly, a fire fighting water hose of 1.5 inch and 1200 m long for water transmission and 3 water operating hoses. Spray gun&#39;s nozzle diameter is 15 mm. There is one gun nozzle. Measured by satellite positioner, lift from the last water outlet position to the water level is 200 m, water outflow is 3.2 m3/h and spraying distance is 10 m, so it can meet fire fighting need. 
         [0034]    Operating process of fire fighting pump  29  includes: 
         [0035]    Motor shaft is driven to rotate by the motor Impeller shaft  2  rotates together with the motor shaft. Thruster  4  fixed on impeller shaft  2  rotates. Impeller assembly  30 &#39;s impeller  5 , retaining ring  6  and end cover  3  rotate irregularly under the action of thruster  4 , thus forming a helical separation mode, increasing water pressure, making water supply distance longer, lift high and volume small so it is unnecessary to install a fire fighting pump  29  at a certain height, it is only to pull the hose to a needed position, installation is quick, simple, not limited by landform and has a wide application filed, and it can meet fire fighting need. 
         [0036]    After survey of landform, operation of remote water pump includes: 
         [0037]    (1) Install equipments: Connect generator  32  and water pump&#39;s power cable, connect water pump&#39;s outlet with hose  33  and place water pump into the water; (2) Turn on the machine: Start generator  32  with a key, turn on the controller of output power switch, operate the controller to start the water pump and pump water to put out the fire; (3) Turn off the machine: Operate the controller to stop the pump, turn off the controller, turn off the generator  32  with a key; (4) Take back equipments: Turn on water relief valve to drain water, disconnect hose  33  from water pump outlet, take out water pump from water, disconnect power cables of generator  32  and water pump and take back hose  33 . 
         [0038]    Precautions for operating remote water pump: (1) Check power cable for damage so as to prevent electric leakage; (2) Probe road and prepare a laying path before laying water hose  33  so as to have a smooth laying of hose; (3) Turn on and turn off the machine strictly according to procedures, otherwise it would affect lifetime of the equipments; (4) It should turn on the water relief valve before removing hose  33 , which can be turned off only after water inside hose  33  is completely drained. 
       Application Example 2 
       [0039]    What differs from application example 1 is that number of the first blades is 6. Submersible water pump introduces a 52-stage impeller assembly, a fire fighting water hose of 1.5 inch and 1200 m long for water transmission and 3 water operating hoses. Spray gun&#39;s nozzle diameter is 15 mm. There is one gun nozzle. Measured by satellite positioner, lift from the last water outlet position to the water level is 170 m, water outflow is 3.2 m3/h and spraying distance is 7.5 m, so it can meet fire fighting need. 
       Application Example 3 
       [0040]    What differs from application example 2 is that number of the first blades is 5. Submersible water pump introduces a fire fighting water hose of 1.5 inch and 1200 m long for water transmission and one water operating hose. Spray gun&#39;s nozzle diameter is 5 mm. There is one gun nozzle. Measured by satellite positioner, lift from the last water outlet position to the water level is 200 m, water outflow is 3.0 m3/h and spraying distance is 10 m, so it can meet fire fighting need. 
       Application Example 4 
       [0041]    What differs from application example 2 is that number of the first blades is 7. Submersible water pump introduces a fire fighting water hose  33  of 10 inch and 140 m long for water transmission and 3 water operating hose. Spray gun&#39;s nozzle diameter is 3 mm. There are 2 gun nozzles. Measured by satellite positioner, lift from the last water outlet position to the water level is 200 m, water outflow is 3.0 m3/h and spraying distance is 10 m, so it can meet fire fighting need. 
       Application Example 5 
       [0042]    What differs from application example 2 is that number of the first blades is 9. Submersible water pump introduces a 30-stage impeller assembly and fire fighting water hose of 1.5 inch and 1200 m long for water transmission and one water operating hose. Spray gun&#39;s nozzle diameter is 15 mm. There is one gun nozzle. Measured by satellite positioner, lift from the last water outlet position to the water level is 50 m, water outflow is 2.2 m3/h and spraying distance is 4 m, so it can meet fire fighting need. 
       Application Example 6 
       [0043]    What differs from application example 2 is impeller assembly  30  includes plastic end cover  3 , plastic thruster  4 , plastic impeller  5  and plastic retaining ring  6 . The number of the first blades is 12. Submersible water pump introduces a 75-stage impeller assembly and fire fighting water hose of 1.0 inch and 1250 m long for water transmission and 2 water operating hoses. Spray gun&#39;s nozzle diameter is 15 mm. There is one gun nozzle. Measured by satellite positioner, lift from the last water outlet position to the water level is 50 m, water outflow is 2.2 m3/h and spraying distance is 4 m, so it can meet fire fighting need.