DE1957634U - SELF-PRIMING CENTRIFUGAL PUMP. - Google Patents

Description

Saint-Gobain Techniques Nouvelles _a

Courbevoie ₉ France

Self-priming centrifugal pump

The innovation also affects self-priming centrifugal pumps Vertical axis »which works without a stuffing box and with the pumped liquid equipped with non-contacting bearings Is it where the pump is particularly corrosive to the transport or dangerous »especially radioactive liquids.

There were already self-priming vertical centrifugal pumps for corrosive or dangerous liquids, in which the impeller of the pump consisting of a horizontal disk is between an upper and a lower one Space is arranged and the disc with one group each is provided with blades on both sides »the end of which

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Measurements and shapes are determined in such a way that the dynamic pressure caused by the on the underside of the disc seated blades is' smaller than the dynamic generated by the blades seated on the top Pressure.

The rotation of the centrifugal pump wheel places among these Operating conditions the transfer of the liquid from the lower or suction chamber into the upper or pressure chamber safe due to wings »which are provided on the underside of the disc» whereby at the same time due to The seal between the environment and the pressure chamber is established by means of wings on the upper side will »without the need for any static seals and / or stuffing boxes. The waterproofing is here supplied by the liquid itself "which" due to the effect of centrifugal force "which is supplied by the wings on the upper side of the disc are created »a stable ring -forms» between the wings and the channel surrounding the control shaft forms permanent.

The present invention aims to improve the operating conditions of a self-priming pump on the one hand » under which the automatic self-priming of the pump takes place exactly »on the other hand the sealing at the Implementation of the rotating shaft during the run or standstill of the centrifugal pump wheel. The invention

wants to look here in particular to various technological implementation details »the series production make it easier for the pump.

According to the invention by the underside of the Centrifugal pump impeller carried wing a special profile in such a way that a vacuum pump operation during the Self-priming is possible.

The profile is preferably built up by connecting two arched parts that form the flanks of the wing and in each case by a part which is slightly inclined with respect to the radius and a part »which is practically tangential to the circumference of the wheel »are formed.

Due to this arrangement, the centrifugal pump impeller starts rotating when the pump 2U self-primes. The practically radial flank of each wing "whose shape is analogous to that of a classic wing or impeller" presses the liquid against the circumference of the wheel or the other flank of the wing causes the sucked air to roll against a liquid _centrifugal ring, this ring being due to the wheel is held by rigid vanes that sit firmly on the inner wall of the pump body.

According to a further feature of the invention, the suction chamber and the pressure chamber have at least one opening in connection »which are at a level above that of the gyro

pump wheel is arranged such that "at standstill in Pump body has a sufficient quantity of liquid for • immediate re-priming tem the next re-start remains. The pressure chamber is expediently provided with a ball valve that prevents the liquid from flowing back brakes the pump body when the centrifugal pump wheel is at a standstill, thus maintaining a liquid reserve automatic self-priming of the pump facilitated.

Due to a particularly suitable construction, all of the elements required to build the pump be made of stainless steel or an alloy or obtained by precision casting »whereby any welding in assembling the device is avoided. The drive arrangement of the centrifugal pump wheel and the pump body is via a removable systm connected at a distance from the liquid suction and pressure lines, which are preferably vertical and coaxial in the Extensions run within each other. Finally, the mechanical drive can be slightly different from the real one Pump body are released.

The device of the invention works naturally without stuffing boxes and bearings "which are not in contact with the pumped FlüssigMt where die.Pumpe especially the transport of corrosive or: allows dangerous, particularly radioactive liquids.

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Exemplary embodiments of the invention are intended to will now be explained in more detail with reference to the accompanying drawings

Fig. 1 schematically shows a vertical section through a self-priming Shows centrifugal pump according to the invention.

Fig. 2 shows part of the impeller from below.

Fig. 3 illustrates a further embodiment of the invention represent.

As can be seen from FIG. 1, the pump body 1 is in the form of a cylindrical container with a flat bottom and a vertical axis. The body is divided into two compartments by a horizontal partition 2, which axially receives a vertical tube 3. _t that runs near the bottom of body 1. This has two channels h and 5 on one of its side surfaces "which are used to suck in and discharge the liquid to be pumped under pressure" whereby the channel k opens into space 6 _s which is delimited inside the body 1 under the horizontal plate 2 "while the channel 5 is connected to the cavity 7 which is located in the body 1 above the plate 2. The channels 1+ and * 5 are connected with a connection piece 8 »in which the ends 9 and 10 of the lines terminate, which lead the liquid to the pump and it after passage through

request the pump. The connection between the part 8 and the body 1 takes place via metal rings 11 and 12 and seals eg 13 »whereby this connection can be made at a distance via a bracket I ¹ +» whose actuation defines the separation or connection between the connector 8 and the pump body 1 .

The centrifugal pump wheel is arranged in the interior of the pump body 1 and is mounted on a vertical drive shaft 16 on the outside attached or keyed by a pin or wedge 17 is. This wheel has according to the arrangements "which are made in the older proposal * wings" e.g. 18 and 19 "on" which are each carried by its top and bottom. The lower wings 19 have after a special feature of the invention a special profile »that makes it possible» the operation of the pump as well as classic centrifugal pump »can also be carried out as a vacuum pump after start-up.

As can be seen from Fig. 2 "the profile of the blades is determined by a connection of the two flanks a and b" of which the former runs practically radially and has a general curvature "whose convexity is formed in the direction of rotation of the gyroscope Vy " as shown schematically by the arrow f in the drawing. The flank of the blade 19 is completely similar to that of the blades of a conventional centrifugal pump wheel.

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borrowed. On the other hand, the. second flank b of the wing »the see with the flank a connects "a practically tangential shape on the circumference of the Hades" whereby a gradually develops narrowing space between the wing 19 and the fixed wing e.g. 2Q becomes possible "that of the body to be worn inside. The flanks a and b of the wing are connected by a curved part c »where the Centrifugal pump impeller preferably 3-6 vanes of the above Art distributed on the underside carries «which are slightly offset from the center ο of the wheel. At the The special profile of the blades allows the pump to start

19 a "rolling" (laminage) of those contained in the device Air against a liquid ring created by the wheel as a result of centrifugal force »whereby the ring in its position against the wheel due to the rigid blades

20 is held. The pump starts self-priming so automatically. During this process, the radial blades arranged on top of the wheel leave one blocking liquid ring arise »as in that older proposal outlined. The pressure of the liquid at this point is then equal to that pressure prevails in the pressure chamber of the pump; the static pressure equilibrium in the liquid ring is automatically established such a »that this liquid ring against the pump impeller and the interior of the housing Closes or seals the outside atmosphere. The wings

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(Th ff '.. "'

Cooperate with a rigid disc 21a which extends beyond the wheel 15 into a rigid coaxial with the drive shaft 16 arranged sleeve 21 also extended.

The upper end of the shaft 16 is connected to an encapsulated electric motor of a type known per se. This motor is fastened to a cylindrical intermediate part 2k by means of a fastening flange 23, which delimits a circular cavity 25 inside the body 1, which, as will be seen below, is reserved for clearing the air expelled through this cavity when the pump starts up. Due to its shape, part 2 ¹ + also delimits a second cavity 26 which is reserved for mounting a valve. This consists of a ball 27 and a seat 28 formed in a disk 28a. Part 2k has an annular groove 29 for a toroidal seal 30 which ensures the seal between the part and the body. On this it is fastened by means of screws 31. In the middle, the part Zk is screwed onto the upper end of the sleeve 21 surrounding the shaft »whereby a system of flexible segments 32 provides a complementary seal during rotation between the upper part of the sleeve 21 and the shaft 16 ensures. The latter has a thread 33 in the middle part "which tries to prevent" liquid droplets from being carried back upwards "

which land against the doeren part of the pump body the body 22 are driven.

According to a "further feature of the invention, the body 1 has a practically radial opening 3k in the knee of the suction line" which connects this channel k with the space 7 "outside the body 1 above the wheel 15" The opening is used to "switch the siphon to idle" which is created by the channel 5 when the pump is at a standstill and through which the liquid quantity can remain inside the body 1 for the next start-up. Other radial bores such as 35 and 36 _a are provided in the socket 21 and allow the intake air to flow through the cavity 25 to the outlet opening 37. The cavity 25 is closed by a plate 38 which protects the transmission of the motor 22 against any projections.

Finally, the pump body is equipped with protective grids 39 ^ O, which are arranged in cavities 6 and 7, respectively. These cavities are provided on both sides of the wheel 15; the grids prevent entry into the pump for voluminous _a in suspension

body. One provided in the bottom of the cylindrical body 1 The stopper allows the device to be emptied completely if required.

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The Pui | pe described above works as follows: Before the start-up, the space 7 is partially filled with liquid up to a height "which is located between the wheel 15 and the base of the intermediate part 2h ", the height being a function of the position of the opening 3 ¹ + and the intake port k .

If the wheel 15 is set in rotation by the shaft of the motor 22, the liquid in the cavity 6 rises into the space 7 via the pipe 3 and the peripheral edge of the wheel 15 Wheel due to the special profile of the blades 19 * as explained above and dispersed in bubbles "which" after passage through the holes 35 "exit the cavity 25 and the openings 37 into the outside atmosphere. The entrained air from the liquid particles are dureh the thread 33 of the shaft 16 and'zurückgeworfen _s back into the cavity 7 or in the interior of the cavity 25 collected.

If the liquid reaches the opening 3 ^ at the level of the Threshold of the suction pipe 4 »so it flows into the lower one Room 6 above »which enables the pump to be primed in this way. At the same time, he lifts in room 7 pressure generated the ball 27 of the valve and sets the pump body with the pressure channel 5 in connection. While of the working cycle, the seal along the shaft 16

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ensured under conditions according to the older proposal.

At a standstill "when the rotation of the wheel Vy ceases ₄ the manometric height in the device becomes zero and the ball 27 of the valve falls back on its seat 28, although the extent of the return takes place slowly over a small recess (not shown)" is left in the disk 28a in such a way that no grooves or grooves in the suction line are required, which would lead to an overflow of liquid to the outside. The protective grille 39 is rinsed in counterflow until the level of liquid stabilizes at a height which corresponds to the idling of the siphon formed by the channel k due to the connection opening 3 ^. The pump is. then ready for a new start with an automatic self-start.

The above-described pump can be disassembled for maintenance or in the event of malfunctions due to its design and execution of its various parts; after flushing and emptying, the entire arrangement of pump body and drives can be removed by simply activating the connecting piece 8 and the channels k and 5 of the bracket Ik can be uncoupled. One can also "remove the drive motor 22 alone" without emptying the body 1 "by removing the part 2k by means of any-

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unscrewed a suitable system for remote control and quick disassembly.

Of course, the invention is not based on the embodiment described above. It can, for example, as shown in FIG. 3, be provided with a coupling of the centrifugal pump wheel with a motor, the immersion rotor of which is arranged below, which leads to a generally reversed arrangement of the parts in the embodiment shown in Fig. 1 AiETührungsform to in both cases, similar parts to refer to * in the latter case a seal is not mfehr necessary by the liquid ring between the underside of the wheel and the rotating shaft "since the rotor kO clad of the engine and so is housed inside a sealed space kl . The centrifugal pump impeller thus only has blades, ^k as shown at 19 », which this time are arranged on the surface and which make the suction of the pump and then normal operation possible. The wings can also be limited by a rotating flange.

- Protection claims -

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Claims (2)

Protection claims: 1. Self-priming vertical centrifugal pump for corrosive or dangerous liquids »when the impeller of the pump consists of a horizontal disc" is arranged between an upper and a lower space, and the disc is provided with a group of blades on both sides " Dimensions and shapes are determined in such _{a way} that the dynamic pressure "generated by the blades on the underside of the disc is" smaller than that generated by the blades on the top ", indicated by blades or blades (19) on the Underside of the centrifugal pump wheel (15) % which have a special profile "such" that the pump works as a vacuum pump during the suction phase. 2. Centrifugal pump according to claim 1 »characterized in that the profile of each wing (19) of the underside des Hades (15) is given by the connection of two arched parts (a; b) which are the flanks of the wing (19) form and each by a slightly inclined towards the radius and from a practically to the circumference of the wheel tangential (b) part are formed. 3 · Centrifugal pump according to one of the preceding claims, characterized in that the suction chamber (6) with the t C t Pressure chamber ($) communicates via at least one opening (3 ¹ O »which is arranged above the centrifugal pump impeller (15) in such a way * that when the pump body (1) comes to a standstill, a sufficient amount of liquid remains for immediate self-priming when the pump is started up. * +. Centrifugal pump according to any preceding claim characterized in that _a that the pressure chamber is fitted with a ball valve (27 ;. 28) "that a deceleration of the flowing back to the pump body (1) at standstill of the centrifugal pump wheel (15) fluid ensures elund so storing a Flüssigkeitsres. erve made it easier for the pump to self-priming. a. -ee.