GB2206621A - Hydraulic pulse generator - Google Patents

Description

-I- HYDRAMLIC PULSE GENERATOR 2206821 T4is invention relates to mining and

hydraulic pulseaction machines, and more particularly to hydraulic pulse generators.

The invention can find application in the mining industry and in waterwor. Ks engineering for breaking rock by high-pressure pulsed water jets. It can also be used in power engineering for cleaning boiler installations of heat-electric generation plants.

There is Anown a hydraulic pulse generator (cf., SU, Aq 7068,968) comprising a hydropneumatic accumulator communicating with a delivery pipeline, an oscillations generator communicating by way of a pipe with the hydropneumetic accumulator, a mechanism for controlling the movement of a hollow piston connected to the oscillations generator, a working nozzle communicating by vay of a pipe with the oscillations tenerator. The diameter of the pipe oetween the oscillations benerator and working nozzle amounts to two-thirds of the diameter of the pipe betweeen the oscillations generator and hydropneumatic accumulator, the length of the two pipes being equal.

Operation of this prior art hydraulic pulse generator involves acceleration of water in the pipe between the oscillations generator and hydropneumatic accumulator through a relief nozzle and auditional acceleration of the water in the pipe oetween tne oscillations generator and working nozzle folloved by deceleration of uhe i'low before the working nozzle.

This apparatus is characterized by an insufficiently - 2 high pressure before the working nozzle obtained at a definite relationship between tne lengtn and diameter of the pipes, which results in low operation efficiency. In addition, as a result of oscillations of the column of water in the pipe between the oscillations generator and working nozzle, a pulse of high pressure before the working nozzle is succeeded by low pressure pulses. which fail to break an object being hydraulicked, reduce the power of the high-pressure water jet. and result in an excessive quantity of water being thrown against the object, in many instances undesirable.

Thereis also &nown a h.,7drauliC Dulse 6enerator (cf., SU, Al 1,102,9%) comprising a hydropneumatic accumulator communicating with a delivery pipeline, a main oscillations -enerator communicating by a pipe with the hydropneumatic accumulator, a mechanism for controlling the movement of a hollow piston connected to the main oscillations generator. a a second oscillations generator mounted before a working nozzle and communicating by a pipe with the main oscillations generator.

Operation of this hydraulic pulse generator is based on accelerating water between the main oscillations generator and hydropneumatic accumulator, and between the main oscillations generator and second oscillations generator through a relief nozzle. An increment in pressure is attained by additionally increasing the speed of water flow in the pipe between the main oscillations generator and second oscillations generator as the water is discharged c - 3 through the relief nozzle.

One ciisadvantabe of this prior art hydraulic pulse generator resides in low efficiency of hydraulicking. This is caused by low energy of any single pulse and can be accounted for by that the amplitude of' U6h pressure before the workin6 nozzle attained at a certain relationship between the length and diamezer of the pipes communicating the hydropneumatic accumulator with the main oscillations generator and tLe main oscillations generator with the second oscillations enerator is not sufficiently high.

Also, as a result of oscillations of the column of vvater in the pipe between tne main oscillations generator and second oscillations generator, a high pressure pulse before the working nozzle is followed by low pressure pulses tailing to exert a breacinz-.. effect on an object being hydraulicked.

c zuchi low Dressure Dulses reduce t'--e power of the water jet and result in too much water tLúrown abainst the object being hydrauliciced.

It is an object of the pesent invention to increase tne el'i'iciency of nydraulicking by makinl--, any sin61e pulse v more po.erfui.

1 1 tnother object is to provide a riyuraulic pulse gene rator of hiEner ei:iiciency.

The objects o-If' the invention are attained by that in a hydraulic pulse 6enerator comprising a hydropneumatic accumulator communicating with a delivery pipeline, a main oscillations L.enerator communicating by way of a pipe with the hydropneumatic accumulator, a mechanism for controlling 4 the movement of a hollow piston connected to the main oscillations senerator, a second oscillations generator comprising a rillousing and a piston with a rod, which form inside tne housinG an after-piston cavity and a rod-end cavity communicating wita a working nozzle and with an inlet tube, the second oscillations generator communicating by way of a pipe with tne main oscillations generator. according to the invention, a non-return valve is provided in the pipe communicating tne main oscillations -enerator with the second oscillations enerator, whereas a second hydropneumatic accumulator is connected to the inlet tuoe of tne second oscillations 6enerator.

Prei'eraul-,, the hydraulic pulse generator according to the invention comprises a source of continuous pressure connectea to the after-piston cavity of tlie second oscillations benerator.

Tne pi,ovision in tne Ape communicatin, the main oscillations 6enerator with the second oscillations 6enerator of a non-return valve allows to make use of only pressure pulses proauced in this pipe as tne main oscillations --enerator sel.f-oscillates. Tne energy of such hieki pressure pulses is stored in the other hyaro)neumatic accumulator connected to the inlet tuoe of the second oscillations 6enerator.

Connection o.: tae source of continuous pressure to the after-piston cavity of the second oscillations generazor ensures concentration o-!' tne ener6y of 11i6L1 pressure pulses and exhaust of viater tnrougil the woricing nozzle to an object ceing hydraulicked at high pressure.

Other advantaSes of the invention will become more fully apparent rrom a more detailed description of a preferred embodiment thereof taicen in conjunction with the accompanying draivin6s illustrating a general sectional view of the proposed hydraulic pulse generator.

A hydraulic pulse generator according to the invention comprises a hydropneumatic accumulator 1 communicatin6 with a delivery pipeline d, a main oscilla tions generator 3 communicating by way or a pipe 4 with tne c.ydropneumatic accumulator 1. A mz;:chanis!n 5 for controllinc. the movement of a hollow piston 6 is connected to the main oscillations 6enerator 3. A second oscillations generator 7 comprises a housing 8 accommodatin- a piston 9 with a piston rod 1C to form an after-piston cavity 11 and a rod-enci cavity 12 communicatin6 with a worAing nozzle 1' und.i,.,-., ar, inlet tube 14.

The secona o--2cillai;ions Eenerator 7 communiciates by way of a pipe, 1;) the main oscillitions c,,:nerator 3; a non-ruturn valv-e 10--- beinG proviaed in tr.e Pipe 15 before the inlet tuoe 14 of the second oscillations generator 7. A second aydropneumatic accumulator 17 is likewise connected to tne inlez tue 14 of tne second oscillations 6enerator The nousing b of the secand oscillations generator has a hole 19 connecting the rod-end cavity 12 with the wor.i.ing nozzle 13. The second hydropneumatic accurrularor 17 is provided with a membrane 20 forced by the pressure of --.as to a grid 21l wLereas the main oscillations generator 3 has a discharge or pressui,e re'Lief nozzle 22.

- 6 The hydraulic pulse generator operates in the following manner.

Suosequent to opening the access of water from the delivery pipeline 2. the mechanism 5 for controlling the movement of the hollow piston 06 initiates self-oscillations, eaca period of self-oscillations incluaing two phases, viz., the low ph-.-se and the high phase.

The low phase of oscillationsbegins after the piston -0 of tne main oscillations enerator 3 has moved toward the pipe 15. Tais is acco-, rtpani,;d by zermination of h-,?draulic communication between the pipes 4 and 15, whereby the pipe IfIr: communicates witill tne pressure relief nozzle d2. The pressure of water in the zone o-L' t'l-le main oscillations c,enerator tends to reduce. and a wave of low pressure (as compared with tne delivery pressure in the delivery DiDeline 2) propagates alon6 tne pipe 4 toward the riv,dropneumatic accumulator 1 having been repulsed by a wave of pressure close to tLe uelivery pressure. iormally, 3 to Yaves of low pressure propagate between the main oscillations --enerator 3 and r-tydropneumatic accumulator 1 in the low phase of pressure oscillations. This operation mode is known as hydraulic nammer, and it enables to v considerably increase pressure in the zone of the main oscillations enerator 3. As every successive repulsed Yjave travels to the main oscillations generator 3. the speed of water flow in tne pipe 4 and the P-ressure in tne zone of tLe main oscillations --enerator 3 tend to increase spasmodically. i,-ien the pressure difference at the piston 6 brov,,s to a magnitude sufficient to cause its movement. the piston 6 assumes a position close to the pipe 4. The pressure relief nozzle d2 closes, and the pipes 4 and 15 communicate to end the low phase of pressure oscillations and start the high phase.

- Upon closinG of the pressure relief nozzle 22 having a relatively low hydraulic resistance, the pressure in the zone of the main oscillations generator 3 grows to become hi6her than the (ielivery pressure. A wave of this high pressure travels along the pipes 4 and 15, the speed of io the flow of in the pipe 15 being hi6her than that in the Dipe 4 due to a smaller diameter of the pipe 15. There fore, shoe&,,,aves of equal pressure but different flow, speed propagate to both sides of the main oscillations gene rator 3. As tne v,ave repulsed from trie nyiropneumatic accu.,aula-uor 1 L.eturns to trie main oscillations generator 3, the piston 6 illoves toward the Pipe 15. The;,ipe 4 coximunicates with the relief nozzle 22, whereby the hydraulic communication thereof with the pipe 15 is terminated. This ends the high phase o. pressure oscillations, and the low phase of oscillations of the flow of water in the pipe 4 is initiated.

On the other hand, the start of the high phase is characterized by propagation of a wave of preliminarily increased pressure from the main oscillations generator 3 along the pipe 4 to reach the non-return valve 16 and cause it to open. Y'Vhile passing throuEh the non-return valve 1Q-', the flow enters the inlet tube 14 of the second oscillations generator 7 to the hydropneumatic accumulator 17.

- 8 and the rod 10 of the piston 9 of the second oscillations generator 7 stops the admission of water to the working nozzle 13. The second hydropneumatic accumulator 17 receives the high pressure flow. Hydraulic resistance to.the flow grows, since its overflow to the hydropneumat accumulator 17 is prevenzed.by the pressure of air above the membrane 20. As a result, the speed of water flow tends to slow down to result in an adaitional increase in the pressure of the flow. Than" to this pressu--e growth the flow overcom,s the resistance of compressed air above the membrane 20 and enters the interior of the hydropneumatic accumulator 17 between the grid 21 and membrane 20, thereby forcing the me-.forane 20 away. Therewith, a wave of this extra high pressure travels 1.5 along the pipe 11- toward the main oscillations generator 3. With equal lengths of the piDes 4 and 15, as this wave approaches the main oscillations Generator 3, a pressure wave repulsed from the hydropneumatic accumulator 1 reaches the oscillations generator 3 from the opposite side. This causes the movement of the piston 6 of the main oscillations generator 3 toward the pipe 15 to start the low phase of oscillations and terminate hydraulic communication between the pipes 4 and 15. For this reason, the pressure at the main oscillations generator 3 at tne side of the pipe 15 reduces to a level somewhat higher than the delivery pressure. whereas the speed of flow eguals zero. and tne wave of this pressure and zero speed propagates along the pipe 15 toward the non-return ic jb - 9 valve 16. As this wave reaches the non-return valve 16, the latter is caused to close, since the force of pressure acting thereon at the side of the hydropneumatic accumulator 17 is greater. In consequence, the pressure before the non-return valve 16 drops for a wave of this pressure and zero speed to again travel to the main oscillations generator 3. Oscillations of the water in the pipe 15 (viz., between two dead ends: closed non-return valve 16 and main oscillations generator) will continue, to be accompanied by a reduction in tae pressure until the low Dhase of flow oscillations in tne pipe 4 ends and hydrau lic coinmunicLtion between the pipes 4 and 15 is resumed.

As soon as this hz:.ppens, the hiGh phase sets on aLain, and u. wave of preliminarily increased pressure will travel alont- the pipe 15 toward the non-return valve 16. The sequence repeats, and the nydropneumatic accumulator 17 again receives the pulse, tnat is a certain amount of water un-er increased pressure. With the reception of this amount, and consequently compression of air above the me.-jorane 2C, ttie hj;ciraulic resistance of the hydropneumatic accumulator 17 tends to be more pronounced to entail a pressure C,,rowth in a wave induced before t',lie non-return valve in the Lign phase. The hydropneumatic accumulator 17 is charged until the pressure of air above the membrane 20 (and the pressure of liquid thereunder) grows to such a ma6nitude that the force produced thereby and exerted on tne surface area ol the rod 10 of the piston 9 overcom--s the force of pressure in the afterpiston cavity 11 ol--- the housing 8 acting on the surface area of the piston 9. As this occurs, the piston 9 departs from the inlet tube 14 and the force acting to move the piston 9 with rod 10 grows, because the pressure at the side of the hydropneumatic accumulator 17 acts on the sur face area of the entire rod 10. Tne piston 9 and rod 10 are caused to move from the inlet tuoe 14 to-ward the source 18 of continuous pressure. A flow of liquid under high pressure pa.:ses turough the rod-end cavity 12 and hole 19 to escape ourside from the working nozzle 13.

The entire volume of vazer under ai6h pressure is tnere fore thrown as a higli power pulsed jet a6ainst an object to be hydrauliciced.

Thereafter, discnart.e of the second dydropneumatic accumulator 17 is initiated.

The eseac)e or water tirouj,-i thle working nozzle 13 is accompanied by a smooth reduction in pressure inside the hjdropneumatic accumulator 17. Yaen 'urle pressure is reducea to trie extent tuat the force at tne sice of trie source 18 of continuous pressure (pressure in t',-le after piston cavity 11 exerted on the surface area of tae pis ton 9) overcomes the force at the sice or tae inlet tuGe 14 (pressure in the hydropneumatic accumulator 17 exerted on the surface area of the rod 10), the Diston 9 with the rod 10 are caused to move to the inlet tube 14 of the second oscillations z---enerator 7. Access of a'U--er to the working nozzle 13 is terminated. Discnarr..e of the second aydropneumatic accumulato- 17 ends to be followed by repeated chargin6 thereof, after which tne operation cycle is recommenced.

Z - 11 The pressure level before the workinn. nozzle 13 depends on the operating conditions of the h.vdraulic pulse generator, relationsuip between working surface areas of the piston 9 and rod 10, initial pressure of air above the nembrane 20 of the second hydropn6umatic accumulator 170 and continuous pressure in the afterpiston cavity 11. By varying the latter in the course of operation or the hydraulic pulse generator it is possible to control the pressure before the working nozzle 13 within certain limits.

The auration of a high pressure pulse before the working nozzle 13, and tne time during which the liquid is exhausted therelfrom depend on the geometripal volume and initial Dressure of air in the second Lydropneumatic accumulator 17, and diameter of the working nozzle 13.

The aerein proposed hydraulic pulse..enerator makes it possible, thanks to the pulsed stora.,,,e of the energy of tne flow of water unue-A an overpressure in the second hydropneumatic accumulator 1'?0 to attain a higher energy of a single pulse of water exhausted from the working nozzle while maintainin- the level of overpressure, which results in a suostantially increased efficiency of hydraulicking. In addition, extra discharge of tae low pressure flow of liquid from tne pipe 15 is prevented, which makes the proposed hydraulic pulse generator more efficient in operation.

The heretofore described embodiment of tne present invention ensures an increase in the efficiency of hydraulicicing trLanks to increasing the energy of a single 30pulse.

Claims (1)

1. A hydraulic pulse generator comprising a first hydropneumatie accumulator communicating with a delivery pipeline, a first oscillations generator communicating by way of a first pipe with the first hLydropneumatic accumulator. a mechanism for controlling the movement of a hollow piston connected to the first oscillations generator, a second oscillations generator comprisinga a housin- and a Diston with a rod, which form inside the houw.inE; an afzer-piston cavity and a rod-end cavity communicatin,.. with a working nozzle and with an inlet tube, the second oscill&4u,-ions generator communicating by way of a second pipe ivith. the first oscillations generator, a non-return valve provided in tLe second pipe, a second hydropneumatic accumulator connected to the inlet tube of the second oscillations generator. d. A bjdra,--lic pulse generator comprising a source of continuous Pressure communicating witn t"-e afterpiston cavity of the second oscillations generator. 20 3. A hydraulic pulse generat;:)r substantially as heretofore Cescribed with reference to the accompanying drawin-.

-%bhslied 19813 at Une Pae.-t Offi,!e. State Heuse. C671 High H--"norn. Lon'-,'n W= 4TP Crpl.=S =a-.- be otza,.-.ed- from The Patent office.

5,:lez Branch. 5, M-:--- Cra. 0-p,n_o-:n. 27ent BRZ- -:R- Printed by eray. Kent Ccr. 1 a 7