The pouring-in positive/negative-pressure foam proportioning system of a kind of foam truck
Technical field
The present invention relates to fire-fighting equipment field, particularly relate to the pouring-in positive/negative-pressure foam proportioning system of a kind of foam truck.
Background technology
When foam truck utilizes category-B foam solution to put out a fire, foam concentrate liquid (calling foam dope in the following text) fully must be mixed with water to scale, be put out a fire by spraying equipment post-foaming.For ensureing extinguishing effect, the mixed proportion of correct water and foam dope and the adequacy mixed are one of important prerequisites forming desired foam.Domestic foam dope conventional 3% and 6% two kind of specification.National Specification, to 3% foam, correct mixing ratio is 3% ~ 4%; To 6% foam, correct mixing ratio is 6% ~ 7%.
The domestic and international category-B foam automatic ratio hybrid system for foam truck has two kinds at present:
Common one is as shown in Figure 1 negative pressure system: by being arranged on the Venturi tube on water feeding of water pump pipeline, draw and sprayed by Venturi tube inner nozzle from one press water of pump outlet, vacuum is produced in hybrid chamber, thus suck quantitative foam dope, mix with water further after together entering water pump water inlet, fully stir realization through impeller and mix output fire extinguishing completely.The pressure reduction that the motive power entering water pump because of foam is formed from vacuum, therefore be called negative pressure system.The limitation of negative pressure system: (1) water feeding of water pump pipeline is generally negative pressure state maybe can not malleation higher than 0.05MPa, otherwise the vacuum that Venturi tube can produce will reduce greatly, thus affect the soakage of foam, reduce the degree of accuracy of mixing ratio and the maximum inlet capacity of system; That is, this system is suitable only for the ratio mixing that water pump (comprises cucurbitula inner storing water) during operation under water suction state, does not meet the water inlet state of " coupling " operation.(2) water pump will consume a part of press water and produce vacuum for Venturi tube injection, and the injection flow of fire monitor can only be less than the metered flow of water pump usually, more or less have impact on injection intensity and the jet length of foam monitor.
Common another kind is as shown in Figure 2 positive pressure system: the power drive foam pump utilizing chassis, is directly injected into a certain amount of foam dope in water pump water outlet pipeline, and realizes putting out a fire with exporting after the mixing of water by dedicated mixer.Pump outlet is barotropic state, therefore claims this system to be positive pressure system.Although existing positive pressure system can work under pump intake is barotropic state, overcome negative pressure system can not " to be coupled " deficiency of operation, but also there are some fatal defects: (1) due to system be to pump outlet inject foam dope, actual injection pressure can improve along with the raising of pump output pressure.Simultaneously, the on-way resistance of foam dope output channel and pipeline fittings as: control valve, check valve, blender etc. the local resistance that produces, both will consume the output pressure of foam pump nearly 1/3rd altogether, this is for maximum import (domestic only can reach 17bar) the special large discharge foam pump that can reach 20bar of operating pressure, lose very huge, cause water pump water outlet pressure namely can not inject foam dope more than 12bar.When not obviously being suitable for " coupling " operation pump outlet pressure energy reach 15bar even higher time foams mix, strongly limit the actual effect of " coupling "; (2) although the foam dope injecting pump outlet just enters water pump water outlet pipeline after special blender, but compare the negative pressure system stirred through water pump vane, water has a great difference with the adequacy that mixes of foam dope, the mixed liquor coefficient of foaming ejected by big gun is caused to have obvious gap, the extreme influence extinguishing effect of positive pressure system.
Current foam truck is using a kind of fire extinguishing mode of operation very with promotion prospect--" coupling " operation.So-called " coupling " operation is that the press water of self-water-supplying fire fighting truck or fire hydrant is in the future directly injected in the pump intake of main-battle firefighting truck, by the continuation acting stack power of car water pump of advocating war, make its performance considerably beyond the one fire extinguishing mode of operation of the specified technical indicator of car of advocating war.
Coupling operating type not only can greatly improve main-battle firefighting truck extinguishing ability, also have the following advantages: when (1) meets an urgent need, can reach more than 20% by the flow of two car " coupling " raising water pump and operating pressure, that greatly improves car of advocating war goes out rifle quantity; (2) highly can to provide support the press water that several hydraulic giants spray to 140m; Also directly can to supply water injection to the mobile monitor outside km; (3) water cannon about jet length 15m can be improved; (4) " coupling " operation can reduce car engine load of advocating war, and reduces engine speed, is conducive to improving fire fighting truck and continues fight capability; (5) " coupling " operation is a kind of work pattern of energy-conserving and environment-protective: directly to water pump moisturizing, and the overflow pipe after by canful during water pot moisturizing can be avoided to run off, and improves the utilization rate of water; Effectively can utilize the water supply energy of fire hydrant or water tender, it is directly added to and advocate war on car, energy-conserving and environment-protective.
The present invention mainly solve how to realize foam truck under bicycle extinguishing operation state and " coupling " operation time all can complete the function that water mixes by correct proportions with foam dope, make foam truck use " coupling " extinguishing operation mode to become possibility.
Summary of the invention
Technical problem to be solved by this invention is to provide the pouring-in positive/negative-pressure foam proportioning system of a kind of foam truck, froth ratio mixing during pump sump operation can be met, froth ratio mixing when can meet again water pump " coupling " operation, special under water pump " coupling " state, discharge pressure reaches more than 15bar, the foam of water flow when exceeding water pump metered flow correctly mix, both merged the advantage of existing two kinds of hybrid systems, overcome its limitation used, and contributed to again using " coupling " operation in drill.
The present invention solves the problems of the technologies described above adopted technical scheme:
The pouring-in positive/negative-pressure foam proportioning system of a kind of foam truck, described positive/negative-pressure state foam proportioning system is connected with outer inlet pipeline by foam pump fluid pipeline, outer inlet pipeline end Bonding pressure water pump water inlet, pressure water pump delivery port connects outlet pipeline.
Described outer inlet pipeline coupling pressure scope: 0 ~ 1.0MPa, force value :-90kPa during negative pressure; Described foam pump fluid pipeline pressure limit: 0 ~ 2.0MPa, range of flow: 0 ~ 16L/s
Described positive/negative-pressure state foam proportioning system is provided with foam tank, and foam tank is connected with foam pump entrance by foam pump filling line, and foam pump outlet connects foam pump fluid pipeline and earial drainage bypass respectively; Foam pump fluid pipeline is provided with fluid injection check valve, and foam pump fluid pipeline lower end is parallel with outer water influent pipeline; The described earial drainage bypass other end communicates with foam tank.
The drive system of described foam pump comprises chassis power takeoff, hydraulic oil pump, hydraulic motor, hydraulic control valve and pipeline component, there are three kinds of different modes to adapt to different chassis and system requirements, be respectively from the power takeoff power taking of side, chassis, drive foam pump by power transmission shaft; From the power takeoff power taking of side, chassis, by hydraulic pump, fluid motor-driven foam pump; By water pump drive spindle power taking.
Described positive/negative-pressure foam proportioning system also comprises proportion adjustment system, and described proportion adjustment system comprises PLC, display and by the vacuum pressure sensor of PLC regulable control, foam tank liquid level gauge, water pot water-level gauge, water flow sensor, foam stream quantity sensor and ratio adjusting valve;
Described vacuum pressure sensor is located on pressure water pump, and described water flow sensor is located on outlet pipeline, and described foam stream quantity sensor is located on foam pump fluid pipeline; Described ratio adjusting valve is electric-controlled type, is located at respectively in foam pump fluid pipeline and earial drainage bypass.
Described positive/negative-pressure foam proportioning system is provided with detergent line, and detergent line is Bonding pressure pump outlet and foam pump filling line respectively.Detergent line working pressure range: 0 ~ 1.0MPa.
Described water flow sensor and foam stream quantity sensor adopt slurry type flowmeter.
Described foam pump filling line is connected with water influent pipeline, and foam pump filling line is provided with foam dope filter.
The present invention adopts the technique effect achieved by technique scheme to be:
(1) the present invention is based on positive pressure system, inlet is arranged on pump intake, set up some sensing devices simultaneously, and by PLC parametric controller, the foam that effective solution water feeding of water pump is respectively under " suction " or " injection " state accurately mixes, solve simultaneously when water pump pump rotary speed when " coupling " do not rise counter fall and flow can substantially exceed rated value time the System Matching Issues that changes of foam dope deliverability.
(2) advantage of negative pressure system and positive pressure system is remained, overcome shortcoming, the overall performance of fire fighting truck and adaptability are improved a lot, particular/special requirement to foaming system when and particularly meets fire fighting truck " coupling " operation, makes thisly have the extinguishing operation mode of promotion prospect to be ensured.
Accompanying drawing explanation
Below in conjunction with accompanying drawing, the invention will be further described
Fig. 1 is existing negative pressure system fundamental diagram
Fig. 2 is existing positive pressure system fundamental diagram
Fig. 3 is structural representation of the present invention
Fig. 4 is routine work of the present invention and the foam flow-pump rotary speed comparison diagram of " coupling " operation
Fig. 5-1 is water pump drive spindle power taking schematic diagram of the present invention
Fig. 5-2 is side power taking schematic diagram in power transmission shaft chassis of the present invention
Fig. 5-3 is side power taking schematic diagram in hydraulic pump chassis of the present invention
Wherein, 1-foam pump, 2-PLC controller, 3-display, 4-detergent line, the outer inlet pipeline of 5-, 6-water pot, the outer water influent pipeline of 7-, 8-pressure water pump, 9-foam pump fluid pipeline, 10-outlet pipeline, 11-foam dope filter, 12-liquid flowing valve, 13-fluid injection check valve, 14-water influent pipeline, 15-foam pump filling line, the bypass of 16-earial drainage, 17-water flow sensor, 18-foam stream quantity sensor, 19-ratio adjusting valve, 20-vacuum pressure sensor, 21-foam tank liquid level gauge, 22-water pot water-level gauge, 23-liquid feed valve, 24-foam tank, the outer liquid-filling valve of 25-, water intaking valve after 26-, 27-cleaning valve, 28-power transmission shaft, 29-transmission shaft support, 30-driving belt, 31-chassis speed changing box power takeoff, 32-water pump transmission system, 33-hydraulic oil pump, 34-hydraulic oil pipe, 35-hydraulic control valve, 36-hydraulic motor
Detailed description of the invention
The pouring-in positive/negative-pressure foam proportioning system of a kind of foam truck as shown in Figure 3, this hybrid system is connected with outer inlet pipeline 5 by foam pump fluid pipeline 9, outer inlet pipeline 5 end Bonding pressure water pump 8 water inlet, pressure water pump 8 delivery port connects outlet pipeline 10.The present invention is different from traditional positive pressure system and foam inlet is connected to water outlet, but is creationaryly connected with inlet pipeline by foam main-inlet, can overcome but namely positive pressure system water pump water outlet pressure can not inject the problem of foam dope more than 12bar.
Positive/negative-pressure state foam proportioning system is provided with foam tank 24, and foam tank 24 is connected with foam pump 1 entrance by foam pump filling line 15, and foam pump 1 exports and connects foam pump fluid pipeline 9 and earial drainage bypass 16 respectively; Foam pump fluid pipeline 9 is provided with fluid injection check valve 13, and foam pump fluid pipeline 9 lower end is parallel with outer water influent pipeline 7, and the effect of outer water influent pipeline 7 can supplement foam dope from extraneous foam bucket when foam pump systems which dispense breaks down; Described earial drainage bypass 16 other end communicates with foam tank (24).
Foam pump (1) drive system as shown in Figure 5 comprises chassis speed changing box power takeoff 31, hydraulic oil pump 33, hydraulic motor 36, hydraulic control valve 35 and pipeline component, there are three kinds of different modes to adapt to different chassis and system requirements, be respectively from the power takeoff power taking of side, chassis, drive foam pump by power transmission shaft; From the power takeoff power taking of side, chassis, by hydraulic pump, fluid motor-driven foam pump; By water pump drive spindle power taking.
Positive/negative-pressure foam proportioning system also comprises proportion adjustment system, the PLC 2 of proportion adjustment system and the adjustable control vacuum pressure sensor 20 of display 3, foam tank liquid level gauge 21, water pot water-level gauge 22, water flow sensor 17, foam stream quantity sensor 18 and ratio adjusting valve 19.Vacuum pressure sensor is arranged on pressure water pump 8, and water flow sensor is arranged on outlet pipeline 10, and foam stream quantity sensor is placed on foam pump fluid pipeline 9; Ratio adjusting valve 19 is electric-controlled type, is arranged on respectively in foam pump fluid pipeline 9 and earial drainage bypass 16.
Operation principle of the present invention is:
1, negative pressure duty, namely water feeding of water pump is " suction " state: this handling situations is generally the operation of fire fighting truck bicycle or other non-coupled handling situations, and the hydraulic pressure in the lower outside water inlet pipe 5 of this handling situations is the malleation that negative pressure state maybe can not have higher than 0.05MPa; Foam source has two, one is the foam dope drawn from outer water influent pipeline 7 by negative pressure operation in fire bucket, two is that foam pump 1 operates and carried by the route of stoste in foam tank 24 along foam pump filling line 15-foam pump fluid pipeline 9, the i.e. pressure state of " malleation foam; negative pressure enters water ", the two enters pressure water pump 8 by outer inlet pipeline 5 and carries out mixing the mix-froth ratio of arrival requirement to realize good extinguishing effect.
2, malleation duty, namely water feeding of water pump is " injection " state: this handling situations is generally " coupling " operating type of multiple stage fire pump tandem working, hydraulic pressure in the outer inlet pipeline 5 of First fire fighting truck is far above specified hydraulic pressure, i.e. " malleation " state, foam dope is injected in outer inlet pipeline 5 with " malleation " state by drive system by foam pump 1 equally, after fully mixing in pressure water pump 8, carry out extinguishing operation via outlet pipeline 10.
Two kinds of job states with the use of the advantage remaining negative pressure system and positive pressure system, overcome shortcoming, the overall performance of fire fighting truck and adaptability improved a lot.
The function mode of detergent line 4 is: close outlet pipeline 10, outer inlet pipeline 5 normal water supply, via the route of pressure water pump-detergent line-foam pump filling line-foam pump fluid pipeline-outer inlet pipeline, realize a circulation, effectively can clean foam solution residual in different pipeline, be convenient to the regular maintenance of pipeline.
The method of operation of earial drainage bypass 16 is: described earial drainage pipeline 16 two-port connects foam pump 1 respectively and exports and foam tank 24, can foam pump 1 overlond running or foam pump water influent pipeline 9 pressure excessive time, unnecessary foam dope is flow in foam tank 24 along earial drainage pipeline 16 again, to reach the object alleviating water influent pipeline hydraulic pressure, it also avoid the excess loss of fire-fighting foams liquid simultaneously.
Routine work is as shown in Figure 4 visible with the foam flow-pump rotary speed comparison diagram of " coupling " operation, foam flow and the proportional relation of pump rotary speed in two kinds of operating types, foam flow increases along with the raising of pump rotary speed, and " coupling " operating type is compared with routine work, in identical pump rotary speed situation, the foam flow of " coupling " operating type is higher, can realize better extinguishing effect, improves fire-fighting efficiency.
Main suitable parameters of the present invention is as follows:
1, foam pump main line pressure limit: 0 ~ 2.0MPa, range of flow: 0 ~ 16L/s (foam pump maximum working pressure (MWP) 1.4MPa, pipeline voltage endurance capability 2.0MPa)
2, fire pump discharge mouth range of flow: 8 ~ 180L/s
3, outer water filling coupling pressure scope: 0 ~ 1.0MPa, force value :-90kPa during negative pressure
4, detergent line working pressure range: 0 ~ 1.0MPa
5, foam pump power: 16kW
Compared with existing fire extinguishing system, the advantage that the present invention has has:
(1) foam pump rated operating pressure is low, and volume is little, failure rate is low;
(2) foam pump flow is large, applied widely, contains existing vehicle and joins various flow fire pump;
(3) foaming system cost is low, and cost performance is high.
The correction data of the present invention and existing single malleation ratio system and single negative pressure ratio system is as follows:
1, the pouring-in experiment of negative pressure foam ratio system bicycle negative pressure
When measuring 6% foams mix ratio, data are as follows
2, the pouring-in experiment of malleation foaming system bicycle malleation
When measuring 6% foams mix ratio, data are as follows
3, the pouring-in experiment of positive/negative-pressure foam proportioning system of the present invention
When measuring 6% foams mix ratio, during water pump water outlet pressure 1.0MPa, data are as follows
In above-mentioned experimental data:
Negative pressure foam ratio system: both can adapt to large discharge and spray, can adapt to again low discharge and spray; Inapplicable coupling is supplied water and is sprayed.
Malleation froth ratio system: pump working pressure only can at 1.2MPa pressure operation, otherwise foam solution can not normally can inject because pipe-line system resistance is excessive; Be not suitable for coupling to spray.Because power superposition causes pump capacity and discharge pressure increasing, rotating speed to decrease on the contrary during coupling, have the foam pump working speed of fixed speed ratio to reduce with water pump, output flow and pressure all do not meet the demands.
Positive/negative-pressure foam proportioning system: the present invention can be suitable for the multiple fire-fighting operation situation such as normal water supply and coupling water supply, and under two kinds of handling situations, foams mix is than all between acceptability limit 6% ~ 7%.