SU1214830A1 - Siphon water outlet of pumping station - Google Patents

Description

The invention relates to hydraulic engineering, namely to siphon water outlets of pumping stations.

The purpose of the invention is to increase the reliability of the water flow.

FIG. 1 shows a siphon outlet, a longitudinal section; in fig. 2 - the same, top view; in fig. 3 - vacuum breakdown valve, general view; in fig. 4 - vacuum breakdown valve, top view; in fig. 5 shows section A-A in FIG. one.

The siphon vodovtusk pumping station includes a siphon 1, the upstream branch 2 of which is connected to the pressure pipe 3 of the pump (not shown) through the bellows 4, which provides the possibility of vertical movement of the upstream branch 2 of the siphon 1. The neck 5 of the siphon 1 has a float 6, made in the form the chamber formed by the double walls of the neck 5. The float 6 placed in the pressure pool 7 provides movement of the ascending branch 2 of the siphon 1 when the water level in the pressure pool 7 changes. The descending branch 8 of the siphon 1 is filled vtusk- nym hole 9. The valve 10 vtolnen vacuum breakdown in the form of high-speed tube 11 installed inside the neck 5 in the bottom of its cross section. In the case of a throat 5 of a rectangular cross section, the vacuum breakdown valve 10 should be located in the lower lateral corners of the throat 5 at the uppermost ridge 12 of the siphon 1 with an average horizon position

waters of the pressure pool 7.

I

The input end 13 of the speed tube 11 is made in the form of a confuser 14, and its output end 15 is open and is located outside and below the neck 5, while the float 6 is made with buoyancy that ensures that the output end 15 of the speed tube 11 exceeds the pressure level of the pressure pool 7

Siphon vodovtusk pump station works as follows.

When starting the pump ij overflow of water through the ridge 12 of the siphon 1, the flow enters the confuser 14 of the speed tube 11 and closes its input end 13, while part of the flow enters the pressure pool 7 through

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output end 15 of the speed tube 1 1.

Subsequently, when charging the bottom of the siphon 1 and the direct current of water in it in the speed tube 11, due to the velocity head, excess polo2 is created.

positive pressure --- O (where tsC is the coefficient of non-uniformity of the distribution of velocity division V over the throat section 5 of the siphon 1, g 9.8 m / s - acceleration of earth attraction), due to which the pressure in the tube 11 is greater than the pressure of the liquid at its 15 output end 15. In this case, the breakdown-vacuum valve 10 is hydraulically closed. The flow of air into the siphon 1 is stopped and its normal operation is ensured. 20 At the moment of stopping the pump, the flow velocity in the throat 5 of the siphon

I is fading. Flow of water from the tube

II stops. Is equal to oiV

property --- o, i.e. overpressure in speed tube 11 is absent. Due to the presence of a vacuum in the throat 5 of the siphon 1, through the outlet end 15 of the tube 11, air begins to flow into the siphon 1 - 30 ST.

. Subsequently, when the flow in the siphon 1 moves in the opposite direction, the pressure in the speed tube 11 becomes negative, i.e. housings35 exact pressure --- i 0. Valve

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10 increases the flow of air into the siphon 1, which is quickly discharged.

Studies have shown that the flow velocity in the throat 5 is usually at least 2.0-2.5 m / s, which corresponds to a velocity head of 20-30 cm. Excess pipe 11 over ypoBHfiM of water in the pressure pool 7 should be in the order of 5-10 cm, which is 1 / 4-1 / 3 of the velocity head in the throat 5 of the siphon 1. In this case, due to the velocity head, the breakdown of the vacuum in the siphon 1 is prevented and the normal operation of the siphon 1 is guaranteed, i.e. ensures reliable operation of the water flow.

Completion of the entry of the speed tube 55 in the form of a confuser 14 makes it possible to increase the magnitude of the velocity head in the tube 11 as compared to its value in the throat 5 of the siphon 1 and

45

50

31

due to this, reduce accordingly the cross-section of the tube 11 and its dimensions.

Studies have shown that the cross-sectional area of the valve 10 for disrupting the vacuum should be within 3-5% of the cross-sectional area of the throat 5 of the siphon 1. However, the confuser 14 allows to increase the magnitude of the velocity head in the tube 11 2 to 4 times. the cross section of the confuser 14 3-5% of the cross-sectional area of the neck 5, it is possible to reduce the cross-sectional area of the velocity

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tubes 11B within 1 / 3-1 / 4 of the area of the inlet section of the confuser 14,

The location of the valve 10 stall 5 vacuum in the lower lateral corners of the neck 5, i.e. in the zones of the least hydraulically active flow, it reduces the active zone, vortexes, and consequently, reduces the area of flow restriction in the throat 5, reduces the hydraulic resistance and thereby increases confusion of the entrance of the velocity tube 1G.

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Compiled by P.Gordiyenko Editor T.Miteiko Tehred L.Mikesh,

864/42 Circulation 642Subscription

VNIIPI USSR State Committee

Inventions n discoveries 113035, Moscow, Zh-35, Raushsk nab., d.4 / 5

Branch PPP Patent, Uzhgorod, Proektna St., 4

Proofreader E. Sirohman

Claims (1)

SIPHON INLET OF A PUMPING STATION, including an ascending branch connected to a pressure pipe with the possibility of vertical movement, a neck, a descending branch, a float fixed on the neck and placed in the pressure basin, and a vacuum stall valve located in the neck, characterized in that, in order to improve the reliability of the water outlet, the vacuum stall valve is made in the form of a high-speed tube installed in the lower part of the neck cross section, and the inlet end of the high-speed tube is made in the form of onfuser, and its outlet end is made open and is located outside and below the neck, while the float is made with buoyancy, ensuring the position of the outlet end of the high-speed pipe, ki above the water level of the pressure head basin. FIG. 1 12148ZD