ACTUATING DEVICE FOR PIPE-CHAMBER FEEDERS OF HYDRAULIC TRANSPORT EQUIPMENTS

Abstract: An actuating device for pipe-chamber feeders of hydraulic transport equipments, the latter having main closing appliances (1A, 1B, ...), auxiliary closing appliances (5A, 5B) and a delivering high-pressure pump (14). The novel feature is that a dashpot (16) or any other pressure storing unit belongs to a pressure equalizer pipe (15) interconnecting the high-pressure pure-water-pipe (8) of the said pump with the auxiliary closing appliances (5A, 5B) and in said dashpot (16) the carrier liquid is in direct or indirect contact with a gas- or aircushion.

Description: Actuating device for pipe-chamber feeders of hydraulic transport equipments Pi el of invention The invention relates to an actuating device for pipe-chamber feeders of hydraulic transport equipments suitable for forwarding solid materials, e .g . coal or slag in form of . a slurry, said equip¬ ments containing valves or other closing appliances . In practice such pipe-chambers are mostly of tubular shape . Bacfc-round of inven ion The function of a chamber /pipe- chamber/ feeder consists of the periodical alternate filling of the chambers with " , slurry at low • pressure and of emptying them at high pressure . While performing this function, the closing appliances, especially valves or sliding valves have to be opened and closed in a certain sequence and at short time periods . IThis can be most advantageously performed in a manner as it is described in the Hungarian Patent Specification No . l6θ 526. If in any of the chambers the flow of slurry is stopped by closing the corresponding closing appliances , said chamber is then pressurized, wmich is relatively time-consuming when known prior-art equipments are used. Tor pressurising, i .e . for increasing the pressu¬ re in a closed chamber , only a limited amount of the water flow deli es ed by the water pump can be used, an amount namely that would not cause considerable caanges in both the quantity and pressure of the water delivered by said pump . 3?ro_n the aforementioned it become obvious that with tradi¬ tional equipments a long-lasting time consuming changeover does not only result from the slow motion of the closing appliances, but also from the fact that the above mentioned pressurizing of the pipe- -chambers is rather time-consumptive too , whereby the output of the equipment is considerably reduced. In addition, he pm__p raili g slurry from the slurry-tank into the pipe-chambers is prevented from working during the long changeover period so that if large quantities of slurry continuosuly arrive, solid matter may deposit in the slurry tank that, can lead to serious break-downs . Summary of invention In order to eliminate the above and other deficiencies it seems to be advisable to reduce the time requirement of said change¬ over . In accordance with the present invention the desired reduction of time for changeover is achieved by shortening the duration of pressure equalizing. According to a basic idea that has led to the present invention it has been required that if pressure is not equa¬ lized merely by a partial water-flow taken from the pressure pipe of the waterpu p during changeover, but for this purpose - entirely or at least partly - stored high-pressure water is used, pressurizing of the pipe-chambers can be performed very quickly, witlv-in a split of the time that has been needed up to now. In addition to this, it will no more be necessary to take a sudden large amount of water from the pressure pipe of the v/ ter-pump in a short period of time, which would negatively influence the operation of the pump concerned. Summing up the above , the essence of the invention lies in the application of a dashpot or any similar pressure storing unit arranged to the pressure equalizer pipe interconnecting the high- -pressure pure -water -pipe of the filling pump with the auxiliary closing appliances , in which pressure storing unit the carrier liquid is subj ected to the effect of a gas— or aircushion. In such a new structure the water in the pressure storing unit will be re-pressurized in the intervals between two changeovers and such stored pressure can be applied to the pipe-chamber upon every change¬ over without any delay within a very short time . Description of a preferred embodiment of the invention The invention will now be described in detail by way of example only, with reference to the accompanying drawing showing the schematical v ew of a feeder with two- ii>e-cl-.aπ. e s, in which.,, when • 5 being in operation, tl:e feeder fills periodically the pipe-chambers with slurry at lor; pressure and it empties them at high pressure . Slurry is fed from a container. 11 by a low-pressure slurry pump 12 via filling pipe 7 into one of the pipe-chambers , while the water having been left therein from the previous cy&le of operation is displaced into a wat er emptying duct 10. Simultaneously, a pump 14 is pressing high-pressure pure water through a pure-water-pipe C into the other pipe-chamber and it expels thereform the slurry having been filled-in during the previous cycle into a slurry pipe 9. The operative steps of changeover are outlined only briefly below, as in a close sense they do not belong to the scope of the invention and they correspond to the pro cess of operation as described in the Hungarian latent Specification No . lβO 526 referred to above and which is incorporated by reference . In the initial working phase the pipe- chamber A is in the stage of filling, while pipe-chamber B is emptied. Pilling and empty¬ ing, are taking place simultaneously with the same time interval. This can be achieved by measuring and controlling the filling and discharg¬ ing flow. Pilling and discharge are performed at considerably different pressures ,- with the value of filling pressure not exceeding 2 to 5 bars , the pressure of discharge may reach 100 to 150 bars depending from the required dist ance and head of delivery. Following the above initial operative phase a changeover is to be carried out in such a way that considerable changes of the pressure in the pipe-chambers will not result in pressure and velo¬ city fluctuations, and thus , swingings or hydraulic impacts towards the delivery pipe and the high-pressure pump are avoided. Changeover is carried out as ollows : a/ Closing appliances 1A, 4A and 6A are closing . In the filled pipe-chamber A the slurry stops to flow, while in pipe-chamber B flow is not interrupted. b/ Auxiliary appliance 5A is opening and simultaneously, the pump 14 applies pressure onto pipe-chamber A by means of the partial flow taken from its pressure pipe. Iλiration of the process is deter¬ mined by the pre-requisite that the partial flow that is taken through the flow-cross-sec ion cleared by the closing appliance 5A should be kept at such a low value that neither the quantity nor the pressure of the water- flow of pump 14 should change considerably . c/ πhen pressure in pipe-chamber A is reaching the required pressure-level, the appliance 2A opens, the path of discharge water is cleared towards the pipe-chamber , as long as the whole flow is passing through pipe-chamber B. d/ The main closing appliance 3A opens while appliance 3B closes . tion of the two main closing appliances is controlled so that the mutually opened cross-sections can be only larger but never smaller than that of one single appliance . Simultaneously, auxiliary closing appliance 5A closes . e/ Appliances 2B and 53 are now closing, pipe-chαnber B does not communicate anymore with the high-pressure pure-water-pipe 8. f/ Auxiliary closing appliance 6B is opening , whereby the pipe-chamber 3 is relieved of pressure towards the water emptying duct 10. g/ Main closing appliances IB and 4B are opening and filling of the pipe-chamber B begins. The sequence of steps described above is then followed by the second phase of operation in the course of which pipe-chamber A is emptied and pipe-chamber B, is filled. Hereon a repeated change¬ over occurs followed by the operational steps as specified above tak¬ ing place in the same order of sequence, but in relation of the pipe-chambers, in a contrary sense . The resulting duration of each of the changeover s occurring in the course of the regular working cycles is composed of the time required for the actuation of the closing appliances and of that required for the change of pressure which takes place through the small-sized auxiliary appliances . A reduction of this latter period of time is of utmost impoπtance, as already mentioned before . Accord- inxtlv, the main objects of the present invention are to reduce the - durations of pressure changes /pressure equalizations/, and simul¬ taneously to provide for the prolongation of the useful life of the water-pumps of the equipments concerned. In order to achieve these , a pressure equaliser pipe 15 branchong-off from the pure-water-pipe S of the water pump 14 consists of a little-diameter part 1 and a large-diameter part 153. Prom the boundary of said two parts a connecting duct 22 - having the same diamtere as the large-diameter part 153 - is starting and it discharges into a dashpot 16. Due to the -fact that the part 15 A is formed with a small diamet er and it also contains a throttle-valve 20 being suitable for flow quantity control, it can be achieved by proper adjusting the possible passing flow that the liquid quantity allowed to flow through said part 15A cannot influence considerably the liquid flow of the pump 14 , even if no pressure prevails in the after-coupled liquid storing dashpot 16. The daspot 16 - a part of which is filled with air or gas - communicates with the auxiliary appliances 5A and 5B via a check valve 17 . ϊϊhen in operation, during the closed position of said closing appliances , in the dashpot 16 effective pressure is built up via the throttle-valve 20. The dashpot 16 is so dimensioned that it is able to discharge the liquid quantity needed for the pressure equalization of the pipe-chambers very quickly and at a slight pressure drop , while the check-valve 17 , the pressure equalized pipe 15 , as well as auxiliary closing appliances 5 A, 53 are dimensioned in such a way that they are able to iead the pressure equalizing flow into the pipe-chambers in a very short time and without any significant loss of pressure . Accordingly, in course of the step b of the above specified changeover process , when one of the auxiliary closing appliances 5 A and 5B opens, in the pipe-chamber in question pressure equalization takes place very quickly . At the same time , this fast pressure equaliz¬ ing procedure will practically not influence the quantity or pressure of the flow of the filling pump 14 and of the pure -water -pipe 8, because - as already mentioned - not even in a pressure relieved state of the dashpot 16 could such a wat er quantity come out , which would considerably change the quantity or pressure of the flow of the water pump 14. In such a manner harmful water impacts and swing¬ ings can be surely avoided and in the course of chamber filling and emptying periods - being far longer than the changeover time - enough time is allowed for the dashpot to be recharged to normal working pressure . By using the described method of pressure equalization,, changeovers can be carried out with a more steady working pressure compared to the st ate achieved- by applying the known prior art metho d according to the Hungarian Patent Specification ΪTo . l6θ 526. Compared to said method, considerable saving of time is provided by using the invention as described above-. According to the drawing, the dashpot 16 is made of metal and its piston 21 is contacting on one side the water coming from the s ll- diameter -part 15 of pressure equalizer pipe 15 , while on the other side there is an air /or gas/ cushion. Liquid storage under pressure can also be realized without a piston, in a container with elastic lining or walls -in a manner known per se . The part 153 of pipe 15 has a large dia-πeter , that means in view of the specification and the claims that its diameter is larger than that of the small-diameter-part 15A. In practice, the ratio of diameters may lie in the range ' between 1 :5 and 1 :8. Pressure and quantity of water delivered by pump 14 from water tank 13 are controlled by means of a slide valve 19. However , the procedure of regulation is unavoidably accompanied by a certain pressure drop; accordingly only a part 8A of the pure-water-pipe S is a full-pressure part , while the part after the slide valve 19 is a reduced-pressure part SB. So it is considered as advantageous, if the pressure equalized pipe 15 starts from the /full -pressure/ part 8A of the pure-water-pipe S. .

Claims: υ _ a i s : 1. Actuating device for pipe-chars er feeders of hydraulic transport equipments, the latter having main closing appliances /IA, 13 ..../, auxiliary closing appliances /5A, 53, 6A, 62 and a delivering high- pressure pump /1 /, c h ar a c t e r i s e d * in that a dashpot /l≤/ or any other pressure storing unite belongs to the high-pressure p re -water-pipe /&/ of the pump /14/ or to ' another duct being in connection with the said pipe /&/ and in said dashpot the carrier liquid is in direct of indirect contact with an elastic means preferably with a gas- or aircushion. 2. Actuating device as claimed ir. claim 1, c h ar a c ¬ e i z e d in that the dashpot /l6/ cr another pressure sto¬ ring unit is in the prescure equalizer pipe /15/ interconnecting; the high-pressure pure-water-pipe /€,/ with the auxiliary closing appliances /5 , 53/. »< • Actuating device as claimed ir. claim 2, c h r a c ¬ t e r i z e d in that the pressure equalized pipe /15/ is connect¬ ed to the pure -water-pipe /8/ at a full-pressure -part /SA/ before a slide-valve /IS/ or any other control organ arranged in the pure- -water-pipe /£/. 4. Actuating device as claimed ir. claim 2 or 3» c h ¬ r a c t e r i z e d in that the pressure equalizer pipe /15/ consists of a small-diameter, part /15k/ and a large-diameter part /15B/, and a connecting pipe /22/ leading to said dashpot /l6/ is starting from the boundary of said two pipe-parts and said connect¬ ing pipe /22/ having a larger diameter than that of the small dia¬ meter part /1 A/. 5. Actuating device as claimed in any of the claims 2 to 4, c h a r a c t e r i z e d in that in the pressure equalizer pipe /15/ between the connecting pipe /22/ and the pure -water -pipe /8/ -ghere is a throttle-valve /20/ suitable for adjusting or controlling the flow of water there through. _• 6. Actuating device as claimed in claip or 5, c a c ¬ t e r i z e d in that in the large-diameter part /15B/ of the pressure equalizer pipe /15/ a check-valve /17/ is arranged.

Inventors: AJTAI LASZLO, ILLES KAROLY, KOCSANYI LASZLO, AJTAI, LASZLO, ILLES, KAROLY, KOCSANYI, LASZLO
Applicants: HEVES MEGYEI TANACSI, KOEZPONTI BANYASZATI FEJLESZTE, HEVES MEGYEI TANACSI EPITOEIPARI VALLALAT, KOEZPONTI BANYASZATI FEJLESZTESI INTEZET
Application year: 1986
Main classification: B65G53
IPC codes: B65G53