AU601799B2 - Air blasting cartridge - Google Patents

Description

r s~,l V V 601 58 0/ 88 ani ndmyrats nadAe und1 r 7 9 9 BUEMPFIM OPrFHI3ALUPIA pif HHTEJIJWNTYAJ~hH~ft COGCTBEHFIOCT b c7 Mew.yHapoufie 6 i0p0 MEXaYTHAPOAHAS1 3ASIBKA, onTYBJIJ4KOBAHHASI B COOTBETCTBP'H4 C LLorOBOPOM 0 flATEHTH-Ofi KOonEPALU1414 (PCT) (51) Mema~ymipoguiam xjjaccmbHk-awj1X (11) Homep Y.ewKayiiapognoft nyI5JnKaw.If: WO 88/10159 1I300peTernIXI~ Al (43) ,LAM meKAYMaHOfH llyOJumfaiwl: B3089 5/02, 9/04 29 xzeKa6pL 1988 (29.12.FB) (21) Ho6mep NeW4vyHapaHoi 3aAnKH: PCT/SU87/00116 (74) Areirr: TOPPOBO-rlPOMbIIIJIEHHA5I FIAJATA CCCP; MocKBa 103735, yn. Kyf16biWCaa, At. 5/2 (SU) (22) PAa Ntewyiiapo2HoH imoxtat: [THE USSR CHAMBER OF COMMERCE AND 21 ox-rs6pq 1987 (21,10.87) INDUSTRY, Moscow (71) 3aaulrreJlb (04,q~ 6cexyKa3aHHblX zocyaapcme, Kpove US): (81) YKa3alffuxe rocygapcma: AT (eaponefcKfff4 naTeHT), MAKEEBCKMA I4HWKEHEPHO-CTPO1HTEJ~h- AU, BE (eaponeIgcK14 naTeHT), BR, CH (eaporiek- HbHI4 HHCTH4TYT (SU/SU]; MaKeeBKa 339023, CKHf4 riaTeHT), DE (aponhCKH naTeHT), FI, FR (eBnbc, 4E3ep) mC1Cro (SU) [MAKEEVSKY INZHE- poneflcmiA naTelIT), GB (eaponeiftcK naTeHT), NERNO-STROITELN'IY INSTITUT, pos. Makeevk,% IT (eaponefiCc~Hft na,-eHT), JP, LU (eapunef1cKHf na- (SLTYI, Tent), NL (eaponekn'1 no-TeHiT), SE (eaponeAcK~hf rnaTe-LT), US (72) H306PITa'reau, H, H306po1TaTeji/3annawreJuI (mno.1bKO 64Ia US): CJIE3 Jleommu EegIanbeB14 [SUISU]; Ma~ceeBKa 339000, 0nfyUJIRnnOBOH YA. O('rpoacicoro, a. a/18, XB. 39 (SU) [SLEZ, Leo- C ocm qemo~t o Ate3IcdynapoOd1om floucKc nid Gedallievich, Makeevka TIOPHH H~aaHOB11q Xanon 341000, np, MeTaJIilyproB, g, 43, KB. 20 (SU) [TJURINj Jury Ivanovich, Zhdanov X.O. IP. 16 M AR 1989 (54) Haaue wo6peTemifM: nHEBMVOHATPOI-

AUSTRALIAN

19 JAN, 1989 PATENT OFI-"

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Abstract A pneumatic chuck comprises a casing divided by 1 piston oriented along Its longitudinal atxis, Into arn Inlet chamber and a pumping chamber The Inlet, charoler is connected to a compressed air source through an air supply pipe passing through an axial opening In the pi eon The pumping chamber Is qonnected to the inlet chamber through an annular gap between the air suppl~f/ pipe and the piston At !ho moment of Its evacuation the pumping chamber Is connected to the atmosphere. !,Me cross-sectional surface (10) of the piston facing the pumping. chamber Is larger than that of the end-face surface of the piston facing the inlet chamber but, smaller than that of the end-face surffine (12) of an annular projection on, the piston facing the pumping chamnber an additional chamber being formed on the Inlet chamber side bysaid projection and by the casing

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(pi411N"flhit OpalfilHs ra6o" BeOuIM66PItTaifig Batirptims ItTanlla .Ano"hiN KopeCixca HapoZWlo-oleMQKpaTHf4OcKux Peeny'6nHxa KapoIcxast Pactiy0jisgKQ UWpu t,aHKa JIIOKCei6ypr MotlaKO Ma~tarackap manno Hiu~epjiatum 1iopaerim Cynalu C~kran 4.QHCTCKIIA C0103 Toro CCIMuCH10i IlinTTi AmeptHKH AIR-BLASTING CARTRIDGE Technical Field The present invention relates generally to water supply and water disposal practice and more specifically to air-blasting cartridges.

One prior-art air-blasting cartridge (SU, A, 130, 454) is known to comprise a housing subdivided into an inlet chamber and a discharge chamber by a piston arranged along the longitudinal axis of the housing. The inlet chamber communicates with a source of compressed air through an air admission tube which passes through an axial port in the piston. The discharge chamber communicates with the inlet chamber through an annular gap left in between the air admission tube and the piston. In addition, the discharge chamber gets connected with the surrounding atmosphere at the instant when it is being discharged.

Compressed air from its source is fed along the air admission tube to the inlet chamber to establish a pressure applied to the piston end adjacent to said chamber,thus forcing the piston against the seat. Compressed air is free to flow to the discharge chamber through the annular gap between the air admission tube and the piston. To actuate the known air-blasting chamber a valve is provided through which an air duct communicating with the air admission pipe can be connected to the atmosphere.

Once the operator has established communication between the air duct and the atmosphere, compressed is free to escape from the air duct, air admission tube and inlet chamber into the atmosphere. As a result, pressure in the i inlet chamber falls and the piston is urged, by virtue of the pressure exerted on the hard surface on the part of the discharge chamber, to move towards the inlet chamber, thus opening through-ports in the housing of the air-blasting cartridge for compressed air to release into the atmosphere.

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i INTERNATIONAL SEARCH REPORT -8 International Application No PCT/SU 87/00116 -I.CLASSIFICATION crF SUIJCr MATTER several classincatlon symbols apply. Indicate all) 2 -2 The heratofore-known air-blasting cartridge discussed above is designed for destructing hard and coal but is inapplicable for cleaning industrial pipelines or vessels containers from consolidated settlings or cake due to the following reasons: provision of a valve (discharge head) makes it impossible to maintain automatically a preset operating mode of the air-blast.ng cartridge within a prolonged period of time; the valve (discharge head) designed for a high pressure, is in fact a complicated contrivanc incapable of providing the necessary reliability of the air-blasting cartridge within e prolonged continuous operating period (that is, it suffices to carry out rock or coal break-down by air blasting only once; considerable length of the air duct -running from the air-blasting cartridge to the valve-attending operator causes considerable loss of compressed air escaping into the atmosphere and affects adversely the piston traverosing speed in the air-blasting cartridge due to a comparatively slow pressure drop in the inlet chamber, which is in turn owing to a great total amiount of compressed air in the air duct, air admission tube and inlet chamber, thus reducing much the air-blast power.

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Summary of the Invention T1he main object of the present invention is to provide a cartridge having such a construction of a piston that would provid~e automatic maintaining of preset operating conditions and possibilit-' of adjusting the operating conditions without interrupting the operation of tbhe airblasting cartridge, a possibility of the air-blasting cartridge operation in liquid media supersaturated with solid suspensions, operating reliability and simple construction and also considerable reduction, of power consumption of the air-blasting cartridge.

r 1' i: 3- This object is accomplished due to the fact in an airblasting cartridge, comprising a housing subdivided, by virtue of a piston arranged lengthwise a longitudinal axis thereof, into an inlet chamber communicating with a source of compressed air through an air admission tube which runs through an axial port of the piston, and a discharge chamber communicating with the inlet chamber through an annular gap between the air admission tube and the piston and adapted to communicate with the surrounding atmosphere at the instant of its discharge, according to the invention, the area of the piston end surface facing the discharge chamber exceeds the area of its end surface facing the inlet chamber but is small.er than the area of the end surface of a piston collar facing the discharge chamber, said collar forming, together with the housing, an additional chamber on the side facing the inlet chamber.

It is necessary to provide the piston vwith a damping device aimed at damping dynamic forces that result from collision of the piston and the housing of the air-blasting cartridge at the instant of an air blast, as well as at returning the piston into the initial position, said damping device being located in the piston collar on the side facing the additional chamber.

It is desirable that the damping device should comp- -ise a circular housing accommodating a damper with a bearing which is adapted to interact with the housing in the zone of the inlet chamber at the instant when the discharge chamber is being exhausted.

Such a construction arrangement provides for operating reliability and long service life of the damping device.

It is expedient that the additional chamber should communicate with the surrounding atmosphere, at the moment of exhausting the discharge chamber, through at least one open-end passage made in the housing close to the inlet chamber, a pressure relief valve being provided at the out- S let of said passage.

-4- 1is feature provides for a considerable reduction of the damping effect produced by the air in the additional chamber and protects the latter against soiling.

The herein-proposed air-blasting cartridge, according to the invention, is applicable for cleaning industrial pipelines used to transfer liquids supersaturated with solid suspensions, various pulps inclusive, and is operable within a wide range of compressed air pressures using automatically adjustable parameters of an air blast. The present air-blasting cartridge features simple construction reliable in operation. Besides, the construction of the herein-proposed air-blasting cartridge provides the maximally possible air-blasting force that of compressedair discharge) and its ability to self-propel along the surface being cleaned when cleaning pipelines.

Brief Description of the Drawing Given below is a specific embodiment of an air-blasting cartridge to be considered with reference to the accompanying drawing, wherein a schematic longitudinal sectional view of the air-blasting cartridge is represented, according to the invention.

Best Mode for Carrying Out the Invention The air-blasting cartridge comprises a housing I as shorn in the accompanying Drawing which is subdivided, by a piston 2 arranged along a longitudinal axis of the piston 2, into an inlet chamber 3 and a discharge chamber 4.

The in/let chamber 3 communicates with a source of compressed air L (omitted in the Drawing) through holes 5 in an air-admission tube 6, which. runs through an axial port of the piston 2 and establishes an annular gap 7 therewith. The inlet chamber 3 communicates with the discharge chamber 4 through the annular gap 7.

A collar 8 is provided on the piston 2 which forms, together with the housing 1, an additional chamber 9 on the side facing tie inlet chamber 3.

5 The area of an end surface 10 of the piston 2 that faces the discharge chamber 4 is greater than the area of an end surface 11 thereof that faces the inlet chamber 3 but is smaller than the area of an end surface 12 of the collar 8 that faces the discharge chamber 4.

The piston 2 is provided vrith a damping device located on the collar 8 on the side facing the additional chamber 9.

The damping device comprises a circular housing 13 which is thread-fitted in the collar 8. The circular housing 13 accommodates a damper 14 with a bearing ring The damper 14 is made from an elastic material, such as polyurethane.

At least one through-passage 16 is provided in the housing 1 within the zone of the inlet chamber 3. Four such through-passages 16 are provided in this particular embodiment of the air-blasting cartridge. A pessure relief valve is provided at the outlet of each of the through-passages 16, said valve comprising a closure 17 under which a ball 18 is fitted, which is forced against the exit port of the through-passage 16 by a spring 19.

Through-holes 20 arranged at an angle to the air-blasting cartridge axis are provided in the housing 1 within the zone of the discharge chamber 4, which ensure traversing of the cartridge in the course of operation.

A reducing union 21 is fitted in the end face of the housing 1 on the side Jf compressed air supply, for the air -blasting cartridge to communicate with the source of compressed air (omitted in the Drawing). A ring-bolt 22 is provided on the reduci4ng union 21 for holding the rope (omitted in the Drawing) with which the air-blasting cartrige is safe-guarded during operation and is withdrawn from the pipeline (omitted in the Drawing).

The air-blasting cartridge of the invention operates as follows.

Compressed air is fed from its source (omitted in the Drawing) along a high-pressure conduit (omitted in the Drawing) and through the reducing union 21, the air admission

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-6 tube 6 and the holes 5 therein to the inlet chamber 3, whence through the annular gap 7 compressed air flows into the discharge chamber 4. As a result, the force of the compressed-air pressure applied to the end surface 11 of the piston 2 urges the latter against the seat, thus shutting off the through-holes Since the end surface 10 of the piston 2 is greater than the end surface 11 thereof, the pressure force exerted upon the end surface 10 after the pressure in the discharge chamber 4 has reached the preset value, exceeds the pressure force applied to the end surface 11 by a value equal to the force friction between the piston 2 and the housing 1. As a result, the piston 2 starts traversing towards the inlet chamber 3. As soon as the piston 2 comes off the seat the compressed air pressure is applied to the end surface 12 of the collar 8 of the piston 2. Thus, the force of the compressed air pressure applied to the piston 2 from the side of the discharge chamber 4 rises drastically, whereby the piston 2 is urged to move practically at once towards the inlet chamber 3, thus opening instantaneously the through-holes 20 and letting compressed air to discharge from the discharge chamber 4 through the holes into the surrounding atmosphere to produce an air blast.

The impact of the piston 2 against the housing 1 within the zone of the inlect chamber 3 is taken up by the damper 14 through the bearing ring 15. Thus, the damper 14 is caused to corapress and accumulate potential energy, which is then transmitted to the piston 2 to return it to the initial position.

A low excess pressure is maintained in the additional chambev 9, accounted for by the hydraulic resistance of the presstire relief valves provided at the outlet of the through-passages 16.

Once the discharge chamber 4 has been exhausted, the compressed air pressure applied to the end surface 11 of the piston 2 and the elastic force of the dam; r 14 acting -1 -7 upon the latter cause the piston 2 to return to the initial position. Then the entire operating cycle is repeated.

It should be noted that the compressed air pressure in the inlet chamber 3 increases but slightly when the piston 2 travels towards said chamber and, once the piston 2 stops, drops quickly down to the value of the compressed air pressure in the aid admission tube 6. Besides, the lapse of time spent by the piston 2 to traverse towards the discharge chamber 4 for the through-holes 20 to shut off exceeds the period of time within which the piston 2 travels towards the inlet chamber 3 for the through-holes to open. This can be explained by the fact that the piston 2 is moved for opening the holes 20 under the force of compressed air pressure exerted upon the end surface 12 of the collar 8 of the piston 2, whereas its traversing for shutting off the holes 20 is actuate: by the force of the compressed air pressure applied to the end surface 11 of the piston 2, which is much smaller in area than the end surface 12. That is why the discharge chamber 4 has time enough to discharge nearly completely, which also adds to the operating efficiency of the air-blasting cartridge.

io loss of compressed air occurs in the air-blasting cartridge according to the invention, since there is not necessary to escape compressed air into the atmosphere for pressure reducing in the inlet chamber in order to actuate the air-blasting cartridge which is the case in the priorart cartridges.

A comparatively high rate of opening the through-holes p 20 enables one to provide a relatively high discharge velo- 30 city of compressed air from the discharge chamber 4 into the surrounding atmosphere and hence to attain generation of high-power shock waves.

Industrial Applicability Background of the Invention The present invention can find most utility when applied for cleaning industrial pipelines that are to transfer A A badly soil-d liquids, various pulps inclusive, as well as voirs of' water-cooling towers, andL. 'ox aes5uoi~iiig vuiLuw hard materials.

Claims (1)

1. 9- The claims defining the invention are as follows: 1. An air-blasting cartridge, comprising a housing subdivided, by a piston arranged lengthwise along a longitudinal axis thereof, into an inlet chamber communicating with a source of compressed air through an air admission tube which runs through an axial port of paid piston, and a discharge chamber communicating with the inlet chamber through an annular gap between said air admission tube and said p1:;ton and adapted to communicate with the surrounding atmosphere at the instant of its discharge wherein the area of the end surface of said piston that faces said discharge chamber is greater than the area of the end surface of said piston that faces said Inlet chamber but is smaller than the area of the end surface of a collar on said piston that faces said discharge chamber, S said collar forming, together with said housing an additional chamber on] the side facing said inlet chamber; and said piston is provided with a f5 damping device situated in said collar on the side facing said additional chamber, 2. An atr-blasting cartridge as claimed in claim 1, characterized In that satd damping device comprises a circular housing accommodating a damper with a bearing ring which is adapted to interact with said housing within the zone of said inlet chamber at the instant when said discharge, chamber is being discharged. 3. An air-blasting cartridge as claimed In claim 1, characterized! in that said additional chamber establishes communication, at the instant when said discharge chamber is being discharged, with the surrounding atmosphere through at least one open-end passage made In said housing close to said inlet chamber, a pressure relief valve being provided at the outlet o. o of said passage. 4, An air-blasting cartridge substantially as hereinbefore described with reference to the drawing, S"ii DATED this TWELFTH day of JUNE 1990 Makeevsky inzhenerno-strottelny instltut Patent Attorneys for the Applicant SPRUSON FERGUSON gr/370r r Z p i) ::I Ta a I- ATR-BLASMIN CARMRIDGE Abstraot -jX the Disolosuwa Ae air-blasting cartridge comprises a housing sub- divided ito an inlet chamber and a discharge chamber by a piston arranged along its longitudinal axis. The inlet chamber communicates with a source of com- pressed air through an air admiLssion tube which runs through ane axial port of the piston The discharge chamber comunicates with the inlet chamber through an annular gap between the air admission tube and the piston The discharge chamber is adapted to com- mmnicate with the surrounding atmosphere at the izistant of Its discharge. The area of the pislon end surface (10) fa- vsng the discharge chamber is greater than the area of the piston end ourfaeo facing the inlet chamber (3) but is smaller than the area of the end ourface (12) of the collar on the piston that faces the discharge cham- ber said collar forming, together with the housing (M)v an additional chamber on the aide facing the inlot chamber w~