CN102762861B

CN102762861B - Measuring pump

Info

Publication number: CN102762861B
Application number: CN201180009711.XA
Authority: CN
Inventors: 谢尔盖·格尔茨; 扬·尼德勒; 安德烈亚斯·克劳斯
Original assignee: Grundfos Nonox AS
Current assignee: Emitec Denmark AS
Priority date: 2010-02-18
Filing date: 2011-02-16
Publication date: 2016-05-18
Anticipated expiration: 2031-02-16
Also published as: EP2362101B1; JP5784636B2; WO2011101121A1; JP2013519831A; US20120312399A1; CN102762861A; EP2362101A1

Abstract

The present invention relates to a kind of measuring pump, it has measuring room (14), the suction passage (32) being connected with measuring room (14) and the pressure channel (20) being connected with measuring room (14) wherein, are provided for disperseing the device of bubble in suction passage (32).

Description

Measuring pump

Technical field

The present invention relates to measuring pump.

Background technology

Measuring pump is generally positive displacement pump and has piston or the film as detrusor, and detrusor is transported by drive motorsMoving. Detrusor is the degree extruding volume to be scheduled in measuring room, thereby this volume is outwards exported from measuring room. Measuring room is logicalOften there are two pipe joints: pressure connection and suction pipe joint, wherein, pressure connection is extended conventionally vertically upward, and inhalesEntering pipe joint extends vertically downward from measuring room.

In the time of the such degassed material of for example hydrogen peroxide of weight feed, can have problems. At this, in measuring room not onlyIn the time of metering, have gas and form, and also have gas formation at the metering room off period of pump. But, the bubble in measuring roomCan cause: the liquid that can not weight feed presets volume by measuring room. Therefore expect will to enter by suction passageThe bubble entering and be present in measuring room is derived from measuring room as quickly as possible.

Summary of the invention

In view of these problems, the object of the invention is to, measuring pump is optimized, make to exist or to lead to by suctionThe bubble that road enters can quickly and reliably be derived from measuring room.

Object of the present invention is achieved by the improved measuring pump of one. Preferred embodiment by the description in literary composition withAnd accompanying drawing provides.

Have in known manner measuring room according to measuring pump of the present invention, measuring room is connected with suction passage, waits to supplyThe medium of answering, particularly liquid to be supplied enters measuring room by suction passage. In addition, measuring room is also connected with pressure channelConnect, the medium of being supplied by measuring pump leaves from measuring room by pressure channel. This supply or this pump-absorb action are with traditionalMode realizes by detrusor, and detrusor is arranged on measuring room or in measuring room. Detrusor can be for example by film or pistonForm.

According to the present invention, in suction passage, be provided for disperseing the device of bubble, or, suction passage is configured to,Can therein the bubble entering by suction passage be dispersed into less bubble. When larger bubble enters by suction passageFashionable, its risk is: these larger bubbles can be attached on the wall of suction passage, and therefore rests on suction passage or meterIn amount chamber. If these bubbles are dispersed into less bubble, its advantage has been to reduce the wind being attached on suction passage wallDanger, and these less bubbles can and further be climbed in pressure channel by measuring room by suction passage.Preferably make the bubble fast rise of the valve downstream in suction passage in measuring room, make bubble preferably at total travel time(time of suction stroke and compression travel subsequently) 80% after arrive the port of export of measuring room, arrive pressure channel,Particularly arrive and be arranged in the delivery valve of pressure channel, thus can be near the terminal of compression travel by bubble from measuring roomExtrude. For example, be arranged on suction passage for disperseing the device of bubble to can be used as add ons (protuberance, rib etc.), excellentChoosing is arranged on the downstream of valve in suction passage or transfer valve. Alternatively, can realize by the changes of section of suction passage rightThe dispersion of bubble or smash, thus larger bubble is dispersed into less bubble.

Further preferably Formation cross-section variation in suction passage, using the device as disperseing bubble, preferred at this for this reasonThis changes of section is discontinuous, that is is for example ladder or platform form. This preferably make suction passage larger,Be that measuring room is adjoined in extended cross section. Preferably the cross section of extended suction passage is greater than the suction passage of conventional metered dose pumpCross section. That is to say, select consciously the cross section of suction passage to be greater than the needed cross section of the normal operation of measuring pump at this, withImprove the discharge of bubble. On the cross section expanding, realize the division of the bubble to rising. Therefore, streamwise is seen, largerFirst bubble is attached on the wall of the one or more suction passages before the cross section that is positioned at expansion. That is to say, bubble firstIn the narrow of suction passage, keep sticking on wall. But due to flowing and buoyancy in suction stroke, part bubbleIn enlarged cross section, divided, and be climbed in measuring room as less bubble subsequently, and arrive and press through measuring roomPower passage.

Particularly preferably the cross section of suction passage is expanded into the second larger cross section from the first less cross section, at this, theThe size of one area of section is 0.3 times to 0.8 times of the second area of section. Be preferably base by the first narrower section selection at thisIn basis and the cross section of the suction passage of conventional measuring pump, the particularly cross section of minimum are suitable. That is to say, be connected in downstreamThe cross section expanding is extended with respect to the cross-sectional sizes of the suction passage of known measuring pump.

Further preferably this less cross section is defined by the valve in suction passage, the i.e. outlet of transfer valve. This outletRepresent the narrowest position in suction passage. Thus, first bubble suspends and is retained in this narrow positions, then narrow at thisThe port of export of narrow portion position is divided in enlarged cross section, and is dispersed into thus less bubble.

Further preferred valve has the retainer of remaining onIn valve body, particularly ball body of valve, andAnd less cross section defines by the free space between rib or edge strip and the valve body of retainer. Retainer or spherical guarantorHold frame and have edge strip or the rib that streamwise extends, valve body imports between these edge strips or rib. These edge strips or rib existRadially inwardly outstanding on downstream end, thus form there the axial stop part of valve body. Liquid to be supplied flows through limitFree space between bar and rib. The common cross-section of this free space has defined the less cross section before enlarged cross section. PreferablyThree or four such ribs or edge strip are set, and they form retainer.

Preferred pressure passage is tilted to Shangdi extension with respect to vertical axis and leaves in the Part I that adjoins measuring roomMeasuring room. By being arranged on the pressure channel in the vertical top of measuring room, i.e. the embodiment of this inclination of output channel,Can realize in the region of pressure channel, there is no may gather bubble, interface, horizontally extending top. By thisPlant the extension of tilting and provide the interface, top that tilts to extend with respect to vertical axis, bubble rises along this boundary face. By thisThe extension bubble being tilted to continues to rising along this surface, and therefore automatically enters pressure channel, and in pressure channelRise. To guarantee in this way: the bubble that is gathered in measuring room upper end due to buoyancy in measuring room enters reliablyIn pressure channel, and discharge as quickly as possible from measuring room by pressure channel.

Further preferably on the Part I at pressure channel, connect the Part II vertically extending in downstream. CauseThis bubble can rise in this part of pressure channel unblockedly and can not gather. In this way canRealization do not have bubble may assemble or adhere to its on, the part of horizontal stretching or the pressure channel of wall.

Preferably in the Part II of pressure channel, valve is set. This valve can be check-valves, as it is in this meteringConventionally the outlet side that is arranged on measuring room in pump is such. In suction stroke at detrusor in measuring room, this valve canPrevent that medium to be supplied is back in measuring room by pressure channel. This valve is arranged in the vertical component of pressure channel,Thereby also advantageously there is no there the face of the level that may gather larger bubble. In addition, this set is favourable,Because this valve is closed by gravity conventionally.

Further preferably correspondingly design the suction passage that passes into measuring room, make suction passage adjoin first of measuring roomIn part, tilt and down extend and leave measuring room with respect to vertical axis. To realize thus: in this part of suction passageThere is no may gather bubble horizontal stretching above. Or rather, due to the extension of this inclination, suction passageIn bubble can extend along the inclination of suction passage be arranged in above wall rise and enter measuring room. Then, bubbleCan continue there to rise and enter into as described above pressure channel.

Further preferably on the Part I at suction passage, connect the Part II vertically extending in upstream. CauseIn this part, there is not face bubble, level that may gather thereon in this yet.

In addition, this to the pressure channel that tilts to extend and also have if desired the Part I of suction passage also allow asWith hitherto known, flatly arrange from measuring room and horizontally outward prolong with respect to the center of measuring room or the side of measuring roomThe passage stretched, pipe joint and possible suction passage and the valve of pressure channel. This is in most of the cases based on structure sideThe reason of face is desirable, thinks that joint and valve provide enough structure spaces, because directly adjoining one of measuring roomSide is typically provided with detrusor (for example film) and driver thereof, thereby has limited there the structure sky for pipe joint and valveBetween. In addition, particularly see along the stroke directions of detrusor, the diameter of pipe joint and valve is greater than the width of measuring room conventionally. JustThis, need to make these parts lateral extension exceed the border of measuring room.

Further preferred in the Part II of suction passage, in the vertically extending part of suction passage, valve is setDoor. This valve can be check-valves as known conventional measuring pump. This check-valves cuts out in compression travel, and thusCan prevent that medium back flow to be supplied is to suction passage, instead of enter pressure channel. Conventionally be utilization by this valve designGravity is closed, and is therefore particularly suitable for being arranged in the channel part of vertical stretching.

About in pressure channel and the possible valve setting in suction passage, it should be noted that, also can beThere arranges multiple valves that series connection arranges.

Further the Part I of preferred pressure passage and/or the Part I of suction passage are along the extrusion back to measuring pumpThe direction of device tilts with respect to vertical axis. Can stagger and be provided for sucking with respect to measuring room side direction in this wayWith the pipe joint (measuring pump is connected with outside pipe-line system by pipe joint) of pressure channel, particularly input and output valveDoor or check-valves. Can stagger these parts are set in a side of detrusor and driver thereof dorsad at this, have foot in this sideEnough for these parts, in particular for the structure space of valve.

Further preferred pressure passage and/or suction passage are connected with measuring room in the outer regions of measuring room. ExcellentSelect measuring room to have around horizontal axis, preferably around the circular cross-section of the stroke axis of detrusor. At this, preferably suction passageLeave measuring room with pressure channel minimum point and peak at measuring room the periphery of measuring room, thus also shape not thereOne-tenth may gather face bubble, that be positioned at level above. Therefore,, by the circular circumference of measuring room, can make to be connected to pressureFace on power feeder connection also rough ground extends and rises to peak, thereby makes the bubble that accumulates in there can continue to riseUntil the entrance of pressure channel, then, bubble here can further rise in the Part I of slant dilation subsequentlyAnd may connect in vertical Part II thereon, and leave from measuring room.

Preferred pressure passage and may also have suction passage, the Part I by its inclination is with respect to vertical directionAngulation extends to direction between 70 degree at 20 degree, further preferably angulation at 10 degree between 60 degree, particularlyAt 10 degree between 60 degree.

In order to improve the discharge of bubble, the Part I of preferred pressure passage and/or the Part I of suction passage straightFootpath is greater than 4mm, is further preferably greater than 5mm, is particularly preferably greater than 6mm, for example, be 6.5mm. Passage by such size is straightFootpath can guarantee that larger bubble also can pass through passage fast, and can not be attached in passage.

Further preferred pressure passage has than under detrusor in the upstream that is arranged at the detrusor in pressure channelThe diameter of You Geng great or cross section. Can realize and make bubble enter pressure by valve as quickly as possible by this embodimentIn power passage, and therefore make measuring room farthest not comprise bubble. Can again pipeline section be reduced in valve downstreamTo traditional size.

In addition, preferably make valve in valve and the suction passage in pressure channel, i.e. hanging down between traditional check-valvesStraight distance is as much as possible little. This means, these valves are arranged on measuring room by near-earth as far as possible, to make to adjoin measuring roomPassage and total volume and the path of liquid to be supplied between two valves as much as possible little. Logical by shortening pressureDistance between valve in road and in suction passage, arrives in pressure channel reducing the valve of bubble from suction passageThe rise time of valve, thus can advantageously make this rise time lower than sucking and the total travel time of compression travel80％。

Vertical range between valve in valve and suction passage in preferred pressure passage is equal to or less than measuring roomPerpendicular to 2.5 times of the maximum gauge of horizontal axis, and be preferably equal to or less than 2 times of this maximum gauge. By this designScheme can realize the less distance between valve.

According to another preferred embodiment, vertical between the valve in valve and suction passage in pressure channelDistance, particularly adjoins the vertical range between the check-valves of measuring room, be equal to or less than form detrusor film outsideFootpath. This film outwards stretches with certain degree the external diameter that exceedes measuring room conventionally because its in this region, be sealed andFix. Because the distance between valve is equal to or less than the external diameter of film, therefore can obtain on the whole the meter of measuring roomThe much compacter structure of amount head, and especially make the volume between valve keep as much as possible little, before this hasGood effect described in face.

Brief description of the drawings

With reference to the accompanying drawings the present invention is illustrated below. In the accompanying drawings:

Fig. 1 shows according to the sectional view of measuring pump unit of the present invention,

Fig. 2 shows the amplification sectional view of the pump head of measuring pump unit as shown in Figure 1.

Detailed description of the invention

This measuring pump unit has the electric machine casing 2 that pump head 4 is installed on it in known manner. In electric machine casing 2Drive motors 6 is set, and it drives link rod 10 by transmission device 8, makes thus central area that link rod 10 makes film 12 linearlyMove back and forth.

On the measuring room 14 of film 12 in pump head 4, form detrusor. Measuring room 14 forms specific volume, and it can lead toCross the motion of film 12 and dwindle and increase, in each stroke of film 12, can supply by the measuring room of pump 14 thusSpecific volume.

Pump head 4 is set to, and pressure connection 16 is located thereon end, and suction pipe joint 18 is positioned at its bottom. By inhalingEnter pipe joint 18 and suck medium to be supplied or liquid to be supplied. The liquid of supplying or measuring by pressure connection 16 outputsBody. Pressure connection 16 and suction pipe joint 18 are set for this reason, to be connected with connecting pipe.

Pressure connection 16 is connected with measuring room 14 by pressure channel 20. At this, this pressure channel 20 has firstPart 22 and the Part II 24 being connected with Part I 22 in downstream. The Part I 22 of pressure channel 20 along with its with respect toThe longitudinal axis A that vertical axis X tilts is upwards extended from measuring room 14. At this, the Part I 22 of this pressure channel 20 passes into passIn the upper end of the conglobate measuring room 14 in the cross section of horizontal axis Y. Meanwhile, Part I 22 edges of pressure channel are back to filmThe direction of the detrusor of 12 forms or electric machine casing 2 is extended obliquely and is left measuring room 14. In the illustrated embodiment, pressure is logicalThe longitudinal axis A of the Part I 22 in road 20 becomes miter angle to extend with horizontal axis Y with respect to vertical axis X. But need explanation, also can select other angle, be preferably the angle between 15 degree to 70 degree. This of the Part I 22 of pressure channelPlant the advantage being in tilted layout and be, can make the vertical Part II 24 of pressure channel 20 in side direction on the one hand, namely edgeThe direction of horizontal axis Y, staggers in the direction back to film 12 with measuring room 14. This connects for force pipe being set in pump head 416 and two valves 26 and 28 of being arranged in pressure channel enough spaces are provided, and needn't place it in motor casingIn the region of body 2. Meanwhile, the inclination of the Part I 22 of pressure channel is extended and is with respect to horizontally extending advantage, canMake to be present in bubble in measuring room 14 does not have obstacle and rises in the Part I 22 of the inclination of pressure channel. CauseThis, at the face of the not larger level that may gather bubble in the top of measuring room. Based on this circular configuration, also make measuring room14 the such moulding of other perisporiums: make bubble can upwards rise to T-shaped mouth or the branch road of pressure channel 20 unblockedly.

In addition, for determining enough large size in the cross section of the Part I 22 of pressure channel 20, in the present embodiment, sectionThe diameter of face is greater than 5mm, thereby makes larger bubble also can pass through without barrier the Part I 22 of this pressure channel 20. Hang downStraight part 24 is connected on Part I 22 in downstream, is provided with two valves that are one another in series 26,28 in this vertical component 24.Due to the vertical stretching of Part II 24, make bubble also can be unblocked in this Part II 24 rise. In addition valve,26 and 28 can close by gravity in known manner.

Pressure channel 20 turns round from measuring room 24 on the peak of measuring room 14. Suction passage 32 is perpendicular relativelyGround, passes in measuring room 14 in bottom. Suction passage 32 has Part I 34 and is connected this Part I 34 in upstreamPart II 36. As the Part I of pressure channel 20, the Part I 34 of suction passage 32 is with its longitudinal axis B phaseBe tilted to downward-extension for vertical axis X and horizontal axis Y. In the embodiment shown in this, longitudinal axis B is with respect to horizontal axisY becomes miter angle equally with vertical axis X, and what can be also still other by this angle Selection be preferably placed between 15 degree and 70 degreeScope in angle. Importantly, the Part I 34 of suction passage 32 is not horizontally extending, as according to of the present inventionThe Part I 22 of pressure channel 20 neither be horizontally extending the same. The inclination of the Part I 34 by suction passage 32 is stretchedExhibition will realize: make bubble in suction passage 32 can be unblocked in this section rise. They are along this part 34Upper wall slide and enter in measuring room 14, then bubble rises in the Part I 22 of pressure channel 20 there, and logicalCross this Part I 22 and be outwards transported to pressure connection 16. Therefore, suction passage 32 also there is no that bubble can amassPoly-on it, interface, horizontally extending top. By making Part I 34 edge film 12 and the motor casings dorsad of suction passage 32The direction of body 2 tilts to extend, can also realize by suction pipe joint 18 and valve 30 and 38 in suction passage 32 along towards sideMeasuring room 14 in the horizontal direction of face and pump head 4 staggers and arranges, thereby these parts are not rushed with arranging of filmProminent.

On Part I 34 in upstream at suction passage 32, be connected with the Part II 36 that vertically X extends,Wherein series connection arranges two valves 30 and 38. Valve 30 and 38 is also two non-returns that can close by gravity in known mannerValve.

In addition, in suction passage 32, be provided for being dispersed in the device of the bubble in the liquid stream entering. In this feelingsUnder condition, this device is realized with the form of enlarged cross section. Valve 30 is made up of ball body of valve, and it is maintained at spherical retainer 31In. This spherical retainer by be parallel to vertical axis X extend rib or edge strip form, at this, between these edge strips fromDefine the stream by valve by space 33. Neutralize the freely sky between the edge strip of spherical retainer 31 at spheroid circumferenceBetween 33 jointly defined the first less cross section, this first cross section is less than the cross section of the suction passage 32 that is connected in downstream. AlsoBe to say, form enlarged cross section at the output of free space 33. This enlarged cross section is designed to, preferably makes the total of free space 33Area of section is between 0.3 times to 0.8 times of area of section of suction passage 32 that is connected in downstream. Can by this embodimentTo realize, make the bubble entering by suction pipe joint 18 be attached to Qi Bishang in free space 33, then going to connectionIn the enlarged cross section of the suction passage 32 in downstream, split into single less bubble, thus can be by larger gas at thisBubble is separated into less bubble, and then, these less bubbles can pass through suction passage 32, measuring room 14 and pressure channel 20Fast rise.

In addition, the side direction of the vertical component 24 and 36 by pressure channel 20 or suction passage 32 staggers, can also be along hanging downNogata is arranged on the first valve 26 on the pressure side relative to one another to X, and the first valve 30 is arranged on to suction side, so that can be totalOn body, make distance between volume and two valves 26 and 30 remain on as much as possible little, particularly this outside measuring room 14Distance between two valves is mainly in the length of the pressure channel 20 of valve 26 upstreams with in the suction in valve 30 downstreamsThe length of passage 32. The advantage of doing is like this, in the time that pump is static, can make to treat supplying media or liquid to be supplied in this regionThe volume of body is as much as possible little, thereby the in the situation that of degassed medium, also only has the gas of minute quantity to discharge, therebyMake the quantity and the size that accumulate in the bubble in this region all remain on as much as possible little. In shown embodiment, valveDistance a between the input side of 30 outlet side and valve 26 equals the external diameter of film 12. Thisly be substantially equal to or little apart from aBe arranged so that advantageously there is minimum vertical range between valve 26 and 30 in film 12 external diameters. In addition, this is apart from a'sSize is equal to or less than 2.5 times of maximum gauge of measuring room 14, and further preferred distance a is less than the maximum gauge of measuring room 142 times.

Reference numerals list

2 electric machine casings

4 pump heads

6 drive motors

8 transmission devices

10 link rods

12 films

14 measuring rooms

16 pressure connections

18 suction pipe joints

20 pressure channels

The Part I of 22 pressure channels 20

The Part II of 24 pressure channels 20

26,28,30 valves

31 spherical retainers

32 suction passages

33 free spaces

The Part I of 34 suction passages 32

The Part II of 36 suction passages 32

38 valves

X vertical axis

Y horizontal axis

The longitudinal axis of the Part I 22 of A pressure channel 20

The longitudinal axis of the Part I 34 of B suction passage 32

A distance

The maximum gauge of d measuring room 14.

Claims

1. a measuring pump, has:

Measuring room (14);

The suction passage (32) being connected with this measuring room (14), wherein said suction passage (32) comprises and adjoins described measuring room(14) Part I (34), described Part I (34) tilts and down extends and leave described meter with respect to vertical axis (X)Amount chamber (14); With

The pressure channel (20) being connected with this measuring room (14), is arranged in the vertical top of described measuring room (14);

It is characterized in that, in described suction passage (32), be provided for disperseing the device of bubble, wherein, at described suction passage(32) in, the discontinuous cross section of structure expands as described for disperseing the device of bubble, wherein, and described suction passage (32)Described measuring room (14) is adjoined in extended cross section.

2. measuring pump as claimed in claim 1, is characterized in that, the cross section of described suction passage (32) is from less first sectionFace is expanded into the second larger cross section, and described the second cross section is the extended cross section of described suction passage (32), wherein, and shouldThe area in the first cross section equals 0.3 times to 0.8 times of area in described the second cross section.

3. measuring pump as claimed in claim 2, is characterized in that, described the first less cross section is by described suction passage (32)In the outlet definition of valve (30).

4. measuring pump as claimed in claim 3, is characterized in that, described valve (30) has the valve remaining in retainerMain body, and described the first less cross section is by being positioned at the free space between rib and the described valve body of retainer (31)(33) definition.

5. the measuring pump as described in any one in claim 1 to 4, is characterized in that, described pressure channel (20) is adjoiningState in the Part I (22) of measuring room (14) with respect to vertical axis (X) be tilted to Shangdi from described measuring room (14) extend fromOpen.

6. measuring pump as claimed in claim 5, is characterized in that, the Part II (24) of described pressure channel (20) is in downstreamBe connected with the Part I (22) of described pressure channel (20), the Part II (24) of described pressure channel (20) is along vertical axis(X) extend.

7. measuring pump as claimed in claim 6, is characterized in that, in the Part II (24) of described pressure channel (20), establishesPut at least one valve (26).

8. the measuring pump as described in any one in claim 1 to 4, is characterized in that, second of described suction passage (32)Divide (36) to be connected with the Part I (34) of described suction passage (32) in upstream, the Part II of described suction passage (32)(36) extend along vertical axis (X).

9. measuring pump as claimed in claim 8, is characterized in that, in the Part II (36) of described suction passage (32), establishesPut at least one valve (30).

10. measuring pump as claimed in claim 5, is characterized in that, the Part I (22) of described pressure channel (20) and/orThe Part I (34) of described suction passage (32) along the direction of the detrusor back to this measuring pump with respect to described vertical axis(X) tilt.

11. measuring pumps as described in any one in claim 1 to 4, is characterized in that described pressure channel (20) and/or instituteState suction passage (32) is connected with described measuring room (14) in the outer regions of described measuring room (14).

12. measuring pumps as described in any one in claim 1 to 4, is characterized in that the First of described pressure channel (20)Divide the diameter of the Part I (34) of (22) and/or described suction passage (32) to be greater than 4mm.

13. measuring pumps as claimed in claim 12, is characterized in that, the Part I (22) of described pressure channel (20) and/Or the diameter of the Part I (34) of described suction passage (32) is greater than 5mm.

14. measuring pumps as claimed in claim 13, is characterized in that, the Part I (22) of described pressure channel (20) and/Or the diameter of the Part I (34) of described suction passage (32) is greater than 6mm.

15. measuring pumps as described in any one in claim 1 to 4, is characterized in that the valve in described pressure channel (20)(26) vertical range (a) between the valve (30) and in described suction passage (32) is equal to or less than described measuring room (14)2.5 times of maximum gauge.

16. measuring pumps as claimed in claim 15, is characterized in that, the valve (26) in described pressure channel (20) and described inVertical range (a) between valve (30) in suction passage (32) is equal to or less than the maximum gauge of described measuring room (14)2 times.

17. measuring pumps as described in any one in claim 1 to 4, is characterized in that the valve in described pressure channel (20)(26) vertical range (a) between the valve (30) and in described suction passage (32) is equal to or less than the film that forms detrusor(12) external diameter.