JP4136971B2 - Rotary joint for slurry fluid - Google Patents

Description

  The present invention relates to a stationary side channel (a channel formed or installed in a stationary side member in a rotating device such as a centrifugal dehydrator or a turbine) and a rotating side channel (a rotating portion of the rotating device (rotation of a dehydrating drum). Rotary joint joints that connect to the flow path formed or installed on the support shaft, etc., especially sludge liquid (sewage sludge, manure sludge, wastewater sludge, general industrial wastewater sludge, etc.) etc. The present invention relates to a slurry fluid rotary joint that is preferably used when a slurry fluid having a high slurry concentration is caused to flow between the two flow paths.

Conventionally, as a rotary joint that connects a stationary flow path and a rotational flow path, a stationary joint case having a cylindrical passage portion connected to the stationary flow path, and a cylinder connected to the rotational flow path A rotating side joint case having a channel-shaped passage portion, a bearing for connecting the two joint cases so as to be relatively rotatable, and a sealing means for connecting and sealing the two passage portions so as to be relatively rotatable. The thing using a mechanical seal is known (for example, refer to patent documents 1).
Japanese Utility Model Publication 4-5587

  However, the conventional rotary joint using a mechanical seal as described above is superior in reliability and durability of the sealing function as compared with the one using an O-ring as a sealing means. Thus, it cannot be used for a rotating device such as a centrifugal dehydrator that handles a slurry fluid having a high slurry concentration such as the above, and its use is greatly limited.

  That is, when handling a slurry fluid such as sewage sludge, slurry components such as sludge enter and accumulate in the sealing function part of the mechanical seal (such as the relative rotational sliding contact part of both seal rings), and within a short period of time. The mechanical seal function will be reduced or lost, and cannot be put to practical use in rotating equipment such as centrifugal dehydrators that handle sewage sludge and the like. This problem is the same in the case where an O-ring or the like is used as the sealing means.

  The present invention has been made in view of such points, and a slurry fluid that is difficult to seal by a general sealing means such as a mechanical seal or an O-ring because the slurry concentration is high, such as sewage sludge and manure sludge. However, it is possible to make a rotary joint for slurry fluids that can flow in a well-sealed state between the stationary side flow path and the rotation side flow path for a long period of time, and has excellent reliability, durability, and practicality. It is intended to provide.

The slurry fluid rotary joint of the present invention that solves this problem is
A rotary side joint case having a cylindrical passage portion connected to a rotation side flow path is connected to a stationary side joint case having a cylindrical passage portion connected to the static side flow path, as a first passage as one passage portion. In a state where the part is inserted concentrically into the second passage part which is the other passage part, it is rotatably connected around the axis of both passage parts to form a series of fluid passages penetrating through both passage parts,
An annular space sealed between the opposing peripheral surfaces of the two passage portions by an annular seal member filled between the opposing peripheral surfaces and a mechanical seal interposed between the joint cases and between the fluid passages. forming a seal chamber which is sealed by a member,
An orifice communicating with the seal chamber is formed in the stationary joint case or the mechanical seal component provided in the stationary joint case ,
Between the joint cases, an annular space closed by two mechanical seals including the mechanical seal and forming a sealed liquid chamber communicating with the seal chamber through the orifice;
In the stationary joint case, a liquid supply path for supplying a sealing liquid having a pressure higher than that of the slurry fluid flowing in the fluid passage and allowed to be mixed into the fluid to the sealing chamber is formed .
The sealing liquid is configured to be supplied and filled from the orifice to the seal chamber.

In the accordance slurry fluid rotary joint, the mechanical seal to seal between the sheet Lumpur chamber and sealing liquid chamber, and a rotary seal ring provided on the stationary seal ring and the rotary side joint case provided on the stationary side joint case It is preferable that the end face contact type is in the form of relative rotational sliding contact, and a pore is formed in the stationary seal ring for communicating the seal chamber and the sealing liquid chamber, and this pore is used as the orifice. The rotation-side joint case has a second passage portion, and the stationary-side joint case has a first passage portion and a cylindrical bearing portion concentrically surrounding the second passage portion. A bearing that couples the joint case so as to be relatively rotatable is loaded between opposing circumferential surfaces of the second passage portion of the rotation-side joint case and the bearing portion of the stationary-side joint case, and the cooling fluid flows into the bearing portion. A liquid passage is preferably formed. In this case, it is preferable that a part of the sealing liquid supplied to the sealing liquid chamber is supplied to the cooling liquid path as a cooling liquid so that the cooling liquid passage communicates with the sealing liquid chamber. Moreover, it is preferable to use a gland packing as the annular seal member. That is, the annular seal member is clamped in the axial direction by a packing presser attached to one passage part and a packing pressing body provided in the seal chamber and provided to be rotatable relative to the other passage part. It is preferable that the gland packing is filled between the two passage portions. In this case, in order to effectively lubricate the gland packing with the sealing liquid, the packing pressing body bites into the packing portion which is the inner peripheral portion or the outer peripheral portion of the gland packing and is in contact with the other passage portion. It is preferable to provide a projection so that the sealing liquid is introduced between the gland packing and the other passage portion at a location where the projection is biting. Further, as the sealing liquid, it is preferable to use the same quality as the liquid component contained in the slurry fluid, and it is generally preferable to use water such as tap water for slurry fluid such as sewage sludge and urine sludge. .

  According to the slurry fluid rotary joint of the present invention, as will be understood from the description below, the slurry fluid can be relatively rotated even when the slurry fluid has a high slurry concentration such as sewage sludge and urine sludge. It can be made to flow satisfactorily over a long period between two flow paths (stationary-side flow path and rotation-side flow path). The slurry fluid rotary joint of the present invention can effectively suppress heat generation and heat loss of the bearing by providing a joint case portion provided with the bearing as a radiator structure with a sealing liquid such as water or a cooling liquid. Also, it can be suitably used for a high-speed rotating device such as a centrifugal dehydrator.

  FIG. 1 is a longitudinal side view showing a first embodiment of the present invention. In this embodiment, a rotary joint (hereinafter referred to as “first rotary joint”) R1 of the present invention is sewage sludge, manure sludge, wastewater sludge. , It is used for the liquid supply part of a centrifugal dehydrator that dehydrates general industrial wastewater sludge. That is, as shown in FIG. 1, the first rotary joint R1 is a sludge supply pipe in which a slurry fluid 1 such as sewage sludge is guided from a stationary flow path (a supply source such as sewage sludge to a liquid supply section of a centrifugal dehydrator). ) The two flow paths 2 and 3 are connected to flow from 2 to the rotation-side flow path 3 (a liquid supply path that is formed through the rotation shaft of the dewatering drum and communicates with the drum) 3. It is configured as follows. In the following description, the terms front and rear mean the left and right in FIG.

  As shown in FIG. 1, the first rotary joint R <b> 1 includes a stationary joint case 4, a rotating joint case 5 connected to the stationary joint case 4 so as to be horizontally rotatable, and a stationary fluid passage portion formed in the stationary joint case 4. A series of fluid passages 6 including 6a and a rotation-side fluid passage portion 6b formed in the rotation-side joint case 5 and sealing means 7 for sealing between the fluid passage portions 6a and 6b are provided.

  As shown in FIG. 1, the stationary side joint case 4 includes a cylindrical first passage portion 8 that forms a stationary side fluid passage portion 6a, and a cylindrical bearing portion 9 that concentrically surrounds the first passage portion 8. These are made of metal (for example, stainless steel such as SUS304) having a double cylinder structure composed of an annular flange portion 10 connecting the base end portions (front end portions) of both portions 8 and 9. The flange portion 10 is connected to the downstream end member of the stationary side channel 2 (the pipe end flange of the sludge supply pipe), and the stationary side fluid passage portion 6a which is the internal space of the first passage unit 8 is the stationary side channel. 2 is connected in communication.

  As shown in FIG. 1, the rotation-side joint case 5 is made of a metal made up of a cylindrical second passage portion 11 that forms a rotation-side fluid passage portion 6b and an annular flange portion 12 that is formed at the outer peripheral portion of the rear end. For example, stainless steel such as SUS304). The inner and outer diameters of the second passage portion 11 are set larger than the outer diameter of the first passage portion 8 of the stationary side joint case 4 and smaller than the inner diameter of the bearing portion 9. The flange portion 12 is connected to the upstream end member of the rotation-side flow path 3 (the rotation shaft end at which the liquid supply path is opened), and the rotation-side fluid passage portion which is the proximal end side internal space of the second passage portion 11. 6 b is connected in communication with the rotation-side flow path 3.

  Thus, as shown in FIG. 1, the rotation-side joint case 5 includes the second passage portion 11 and the bearing portion in a state where the distal end portion of the first passage portion 8 is inserted concentrically into the second passage portion 11. A pair of front and rear bearings 13a and 13b are interposed between the stationary joint case 4 and the stationary joint case 4 so as to be rotatable and immovable in the axial direction, and rotated together with the rotating shaft of the dewatering drum. The bearings 13a and 13b are loaded between the distal end portion (rear end portion) of the bearing portion 9 and the proximal end portion (rear end portion) of the second passage portion 11, and are appropriately disposed before and after the bearing loading region. A number of oil seals 14a, 14b are arranged. In this example, three oil seals 14a are arranged on the front side (inside the joint) of the bearing loading area, and one oil seal 14b is located on the rear side (outside of the joint) of the bearing loading area. Is arranged. The oil seals 14a and 14b have the outer peripheral portion fitted and fixed to the bearing portion 9, and the inner peripheral surface is brought into press contact with the second passage portion 11 or the outer peripheral surface of the bearing retainer 15 fitted and fixed thereto so as to be relatively rotatable. Ceramic coatings 11a and 15a are applied to the annular surface portion (the outer peripheral surface of the second passage portion 11 or the outer peripheral surface of the bearing retainer 15) that is in contact with the inner peripheral surface of the oil seal. ing. The bearing 9 of the stationary joint case 4 is provided with appropriate grease (for example, lithium-based grease) 16 between the bearings 13a and 13b, between the bearings 13a and 13b and the oil seals 14a and 14b, and between the oil seals 14a and 14a. A grease injection path 17 (partly provided with a plug 17a) for injection is formed.

  As shown in FIG. 1, the sealing means 7 includes an annular seal member 20 filled between the opposed peripheral surfaces of both passage portions 8 and 11, and a first mechanical seal 21 interposed between both joint cases 4 and 5. A seal chamber 22 which is an annular space formed on the opposing peripheral surfaces of the passage portions 8 and 11 and is closed by the annular seal member 20 and the first mechanical seal 21, and a sealing liquid 23 higher in pressure than the slurry fluid 1. A sealing liquid supply path 24 that supplies the sealing chamber 22 is provided.

  As shown in FIGS. 1 and 3, the annular seal member 20 seals between the fluid passage 6 and the seal chamber 22, and is arranged in the packing presser 25 and the seal chamber 22 attached to the second passage portion 11. The gland packing is filled between the passage portions 8 and 11 while being pressed in the axial direction by the first passage portion 8 and the packing pressing body 27 provided so as to be relatively rotatable. The packing retainer 25 is made of metal (for example, stainless steel such as SUS304) having a cylindrical retainer portion 25a inserted between the passage portions 8 and 11 to press the end surface (rear end surface) of the gland packing 20 on the side opposite to the seal chamber. Steel) and is attached to the base end portion (rear end portion) of the second passage portion 11 by a bolt 28. The packing pressing body 27 is an annular body made of metal (for example, stainless steel such as SUS304) whose inner and outer diameters are substantially matched with the outer diameter of the first passage portion 8 and the inner diameter of the second passage portion 11. One spring that is mounted so as to be movable in the axial direction while being relatively rotatable with the passage portion 8, and is interposed between an annular spring receiving portion 29 that projects from the inner peripheral portion of the second passage portion 11. 26 is pressed against the seal chamber side end surface (front end surface) of the gland packing 20. That is, the gland packing 20 is pinched (compressed) in the axial direction between the packing presser 25 and the packing pressing body 27 by the elastic force of the spring 26. The spring 26 is inserted into the first passage portion 8, and the elastic force is such that the contact surface pressure (seal pressure) to the passage portions 8 and 11 determined by the clamping pressure of the gland packing 20 is appropriate. Set to

  By the way, the gland packing 20 is provided in a state in which the packing presser 25 and the packing pressing body 27 for clamping the gland packing 20 do not rotate relative to the passage portion 11 of the rotation-side joint case 5 (the packing pressing body 27 includes the spring 26). Therefore, when the rotation-side joint case 5 rotates, the gland packing 20 rotates together with the second passage portion 11, and the second-passage portion 11 rotates. Sliding (relative rotation) occurs between the one passage portion 8. Therefore, in order for the sealing function by the gland packing 20 to be properly exhibited, the gap between the inner peripheral surface of the gland packing 20 and the outer peripheral surface of the first passage portion 8 needs to be appropriately lubricated by the sealing liquid 23. However, in the first rotary joint R1, the following measures are taken so that the seal portion of the gland packing 20 (the portion that makes a relative rotation sliding contact with the first passage 8) is well lubricated by the sealing liquid 23. It is.

  That is, as shown in FIGS. 3 and 4, the protrusion 27 a that bites into the inner peripheral side portion of the gland packing 20 in contact with the first passage portion 8 on the rear end surface of the packing pressing body 27, that is, the contact surface with the gland packing 20. In the packing portion 20a in which the protrusion 27a bites in, the sealing liquid 23 is devised so that the sealing liquid 23 can enter between the gland packing 20 and the first passage portion 8. Therefore, when the rotation-side joint case 5 rotates, the sealing liquid 23 that has entered the packing portion 20a is introduced into the contact portion (seal portion) between the gland packing 20 and the first passage portion 8, and the seal portion is lubricated. . It is preferable to provide a plurality of protrusions 27a at equal intervals in the circumferential direction of the packing pressing body 27. However, providing more protrusions than necessary leads to a large amount of leakage of the sealing liquid 23. It should be set appropriately according to the sealing conditions. In this example, as shown in FIG. 4, four protrusions 27a are provided. Further, the amount L1 of the protrusions 27a biting into the gland packing 20 must be increased more than necessary in order to prevent a large amount of the sealing liquid 23 from leaking. As shown in FIG. 3, it is preferable to set the gland packing 20 so that it is half or substantially half the axial length L0. A ceramic coating 8a is provided on the outer peripheral surface portion of the first passage portion 8 with which the gland packing 20 contacts in order to reduce the frictional force with the gland packing 20 as much as possible in combination with the lubrication by the sealing liquid 23. It has been subjected.

  As shown in FIGS. 1 and 2, the first mechanical seal 21 has an axis line on the rotary seal ring 30 fixed to the passage portion 11 of the rotary side joint case 5 and the flange portion 10 of the stationary side joint case 4 facing this. A stationary seal ring 31 movably held in a direction and a spring 32 that presses and urges the stationary seal ring 31 against the rotary seal ring 30, and seals by the relative rotational sliding contact action of both the seal rings 30, 31. It is an end surface contact type mechanical seal configured to seal between the chamber 20 and a sealed liquid chamber described later. The rotary seal ring 30 is fitted and fixed to the distal end portion (front end portion) of the second passage portion 11 via an O-ring 33, and relative rotation with respect to the second passage portion 11 is prevented by the drive pin 34. The stationary seal ring 31 is an annular body composed of a main body portion 31a that contacts the rotary seal ring 30 and a holding portion 31b that fits and fixes the main body portion 31a. The holding portion 31b is held by the flange portion 10 via the O-ring 35. At the same time, by being engaged with a drive pin 36 provided on the flange portion 10, the stationary joint case 4 is held so as to be movable in the axial direction and not relatively rotatable. The spring 32 is interposed between the holding portion 31 b of the stationary seal ring 31 and the flange portion 10, and urges the stationary seal ring 31 to press and contact the rotary seal ring 30. In this example, the main body 31a of the rotary sealing ring 30 and the stationary sealing ring 31 is made of silicon carbide, and the holding part 31b of the stationary sealing ring 31 is made of titanium.

  As shown in FIG. 1, the sealing liquid supply path 24 is an annular space formed between the joint cases 4 and 5, and a sealing chamber 37 adjacent to the sealing chamber 22 via the first mechanical seal 21. It consists of supply and discharge liquid passages 38 and 39 for circulating and supplying the liquid 23 to the sealed liquid chamber 37, and an orifice 40 formed in a mechanical seal component provided in the stationary side joint case 4, that is, the stationary sealing ring 31.

  The sealing liquid chamber 37 is an annular space formed between the bearing portion 9 of the stationary joint case 4 and the passage portion 11 of the rotating side joint case 5 as shown in FIGS. It is closed by two mechanical seals 21 and 41 interposed between 4 and 5. That is, the sealing chamber 37 is sealed between the seal chamber 22 and the bearing chamber 42 provided with the bearings 13a and 13b and the oil seals 14a and 14b. Sealed by a second mechanical seal 41. As shown in FIGS. 1 and 2, the second mechanical seal 41 is disposed at a position close to the foremost oil seal 14 a, and is arranged on the inner peripheral surface of the bearing portion 9 via an O-ring 43 and a drive pin 44. It is disposed between the stationary sealing ring 45 made of carbon that is fitted and fixed, the spring holding ring 46 that is fitted and fixed to the tip of the second passage portion 11, and the stationary sealing ring 45 and the spring holding ring 46. A rotary seal ring 48 fitted and held in the second passage portion 11 via an O-ring 47 so as to be movable in the axial direction is interposed between the spring holding ring 46 and the rotary seal ring 48. And a spring 49 that urges the stationary seal ring 45 to be pressed against the stationary seal ring 45, and is configured to shield and seal the sealing chamber 37 and the bearing chamber 42 by the relative rotational sliding contact of the seal rings 45 and 48. End face contact type mechanical Is Lumpur. The rotary seal ring 48 includes a silicon carbide main body 48a that contacts the stationary seal ring 45, a titanium holding portion 48b that fits and fixes the main body 48a, and a stainless steel drive collar 48c that is fixed to the holding portion 48b. The drive pin 50 attached to the drive collar 48c is inserted into and engaged with the spring holding ring 46, thereby allowing the rotary seal ring 48 to move in the axial direction and preventing its relative rotation with respect to the second passage portion 11. is doing. As shown in FIG. 1, the seal liquid 23 a leaked to the shaft seal chamber portion 42 a between the foremost oil seal 14 a and the second mechanical seal 41 is discharged to the bearing portion 9 of the stationary joint case 4. A drain 51 is provided. In this example, the O-rings used for the joint cases 4 and 5 and the mechanical seals 21 and 41 are all made of fluoro rubber.

  As shown in FIGS. 1 and 2, the liquid supply path 38 is formed in the stationary joint case 4 and is opened to the sealing liquid chamber 37, and the sealing liquid 23 supplied from the sealing liquid supply line 38a is supplied to the sealing liquid chamber. 37 is supplied continuously. As shown in FIGS. 1 and 2, the drainage passage 39 is formed in the stationary joint case 4 and is opened to the sealing liquid chamber 37, and the sealing liquid 23 is discharged from the sealing liquid chamber 37 to the sealing liquid discharge line 39a. To do. Both lines 38a, 39a constitute a circulation circuit having a pressure adjusting mechanism, and keep the pressure of the sealing chamber 37 within a certain range while circulating the sealing solution 23 to the sealing chamber 37. That is, the pressure of the sealing liquid 23 in the sealing liquid chamber 37 is maintained so as to be slightly higher than the pressure of the slurry fluid 1 flowing in the fluid passage 6 (for example, about 0.05 MPa higher than the pressure of the slurry fluid 1). Is done. As the sealing liquid 23, a liquid that is allowed to be mixed into the slurry fluid 1 is used, and generally a liquid having the same quality as the liquid component of the slurry fluid 1 is used. In this example, since the slurry fluid 1 is sewage sludge, sewage sludge, etc., fresh water (normal temperature) such as tap water is used.

  As shown in FIGS. 1 and 2, the orifice 40 is a single pore formed through the holding portion 31 b of the stationary seal ring 31 in the radial direction, and communicates both the chambers 22 and 37. The sealing liquid 23 is supplied and filled from the sealing liquid chamber 37 to the sealing chamber 22. In general, it is preferable that the diameter of the pore 40 as an orifice is about 1 mm, and in this example, it is set to 1 mm. Note that the number and diameter of the pores constituting the orifice 40 can be set as appropriate according to the allowable mixing amount of the sealing liquid 23 into the slurry fluid 1, and are arbitrary if the allowable mixing amount is not limited. Can be set to

  In the first rotary joint R1 configured as described above, between the inner region (fluid passage 6) and the outer region (bearing chamber 42, etc.) of the passage portions 8 and 11 in both joint cases 4 and 5. A seal chamber 22 filled with a sealing liquid 23 higher in pressure than the slurry fluid 1 flowing in the fluid passage 6 is interposed, and as a sealing means of the seal chamber 22, a gland packing 20 is provided at a location in direct contact with the slurry fluid 1. The end-contact type mechanical seal (first mechanical seal) 21 is used in a place where it is used and does not come into contact with the slurry fluid 1, and the sealing liquid is supplied to the seal chamber 22 through the orifice 40. Therefore, even when the slurry fluid 1 has a high slurry concentration such as sewage sludge and manure sludge, the slurry fluid 1 leaks over a long period of time. It can be excellently flow without causing.

  That is, since the seal chamber 22 is sealed with the sealing liquid 23 having a pressure higher than that of the slurry fluid 1, the slurry fluid 1 flowing from the stationary side fluid passage portion 6a to the rotation side fluid passage portion 6b is in the two passage portions 6a. , 6b does not leak.

  Moreover, although the gland packing 20 does not exhibit a high-level sealing function like a mechanical seal, the sealing function is not reduced or lost in a short time due to contact with sewage sludge or the like unlike a mechanical seal. That is, if a mechanical seal, for example, the first mechanical seal 21 is used at a position where it contacts the slurry fluid 1, a secondary seal portion (held by the O-ring 35) between the sealing rings 30 and 31 that rotate relative to each other and the stationary sealing ring 31. Slurry components such as sludge intrude into the part) and the sealing rings 30 and 31 do not come into proper contact with each other or the follow-up operation (axial displacement) of the stationary sealing ring 31 becomes defective. The sealing function will be reduced or lost. However, since the gland packing 20 is not capable of exhibiting a sophisticated sealing function like the mechanical seal 21, the sealing liquid 23 having a pressure higher than that of the slurry fluid 1 is a seal portion of the packing 20 (the first passage for relative rotation). From the contact portion with the portion 8) to the fluid passage 6 side, thereby preventing the slurry fluid 1 from entering the seal portion. Therefore, the sealing function of the gland packing 20 is not lowered or lost due to contact with the slurry fluid 1. Moreover, since the gap between the gland packing 20 and the first passage portion 8 is lubricated by the sealing liquid 23 leaking from the seal portion, damage to the gland packing 20 due to contact wear with the first passage portion 8 is prevented, The sealing function by the gland packing 20 is satisfactorily exhibited over a long period of time.

  By the way, as long as the leakage of the sealing liquid 23 from the gland packing 20 is very small, the sealing liquid 23 is of the same quality as the liquid content of the slurry fluid 1, so that any problem is caused by the leakage sealing liquid 23 being mixed into the slurry fluid 1. Does not occur. For example, for sewage sludge, sewage sludge, and the like that are dehydrated by a centrifugal dehydrator, even if a small amount of water used as the sealing liquid 23 is mixed, the subsequent dehydration process is not affected at all. Further, the sealing portion of the gland packing 20 is lubricated by the sealing liquid 23. However, if this lubrication is not sufficiently performed, the gland packing 20 is damaged due to contact wear with the first passage portion 8, and a large amount of leakage occurs. Will occur.

  Therefore, in order to satisfactorily seal the slurry fluid 1 over a long period of time, leakage from the seal portion of the gland packing 20 is sufficient to allow sufficient lubrication at the contact portion between the gland packing 20 and the first passage portion 8. In general, it is necessary that the amount of leakage is so small that the slurry fluid 1 is not adversely affected. However, such a request is satisfied by providing the first mechanical seal 21 and the orifice 40. The

  That is, since the sealing chamber 22 and the sealing liquid chamber 37 adjacent to the sealing chamber 22 communicate with each other through the orifice 40 which is a fine hole, the sealing from the orifice 40 to the sealing chamber 22 is performed in response to leakage from the gland packing 20. Even when the liquid supply amount is automatically controlled and the pressure of the slurry fluid 1 flowing in the fluid passage 6 fluctuates, the leakage amount from the gland packing 20 is always within the appropriate range (hereinafter referred to as “appropriate leakage amount”). Retained. For example, when the leakage from the gland packing 20 temporarily increases from the appropriate leakage amount, a flow rate difference in an increasing direction is generated between the sealing liquid supply amount from the orifice 40 to the seal chamber 22 and the appropriate leakage amount. The sealing liquid flow rate in the inside (in the flow path formed by the pores) increases. As a result, a loss corresponding to the speed increase occurs, so that the amount of sealing liquid supplied from the orifice 40 to the seal chamber 22 decreases, and the leakage amount from the gland packing 20 is instantaneously adjusted to an appropriate leakage amount. On the contrary, when the leakage from the gland packing 20 is reduced below the appropriate leakage amount, a flow rate difference in a decreasing direction is generated between the sealing liquid supply amount from the orifice 40 to the seal chamber 22 and the appropriate leakage amount. Since the sealing liquid flow rate becomes smaller and the loss decreases as the speed decreases, the amount of sealing liquid supplied from the orifice 40 to the seal chamber 22 increases, and the leakage amount from the gland packing 20 becomes the appropriate leakage amount. Will be adjusted instantly. When the orifice 40 is formed on a rotating member (the rotary joint case 5 or a mechanical seal component provided on the rotary joint case 5), the sealing liquid supply amount from the orifice 40 may become unstable depending on the rotation conditions. There is sex. Therefore, in order for the above-described orifice function to be satisfactorily exhibited, the orifice 40 should be formed on a non-rotating member.

  Further, since the mechanical seal 21 is used as a means for sealing the seal chamber 22 together with the gland packing 20, that is, the space between the seal chamber 22 and the sealing liquid chamber 37 is highly sealed by the first mechanical seal 21. The pressure in the seal chamber 22 fluctuates to accurately reflect the leakage from the gland packing 20. As a result, the above-described orifice function is properly exhibited, and the leakage control from the gland packing 20 is favorably performed. If an annular seal member having a low sealing function such as the gland packing 20 is used instead of the first mechanical seal 21, the pressure in the seal chamber 22 does not accurately reflect the leak from the gland packing 20, Therefore, the orifice function described above cannot be properly performed.

  Accordingly, the seal portion of the gland packing 20 is always properly lubricated by the sealing liquid 23, and the leakage from the seal portion is maintained at an appropriate leakage amount. The slurry fluid 1 can flow well from the stationary side channel 2 to the rotation side channel 3 even when the slurry fluid 1 has a high slurry concentration such as sewage sludge and manure sludge. Can do.

  By the way, the above-described orifice function is more effectively exhibited by setting a part 20a of the gland packing 20 as a non-sealed part by the protrusion 27a of the packing pressing body 27. That is, the sealing liquid 23 in the seal chamber 22 actively invades the packing portion 20a in which the protrusion 27a is biting. Therefore, as the rotation-side joint case 5 rotates, the packing portion 20a is placed on the contact portion between the gland packing 20 and the first passage portion 8 (more precisely, the contact portion between the gland packing 20 and the ceramic coating 8a). The sealing liquid 23 that has entered from the inside gradually permeates, and the contact portion is well lubricated. As a result, even when the first rotary joint R1 is installed in a high-speed rotating device such as a centrifugal dehydrator and the gland packing 20 and the first passage portion 8 rotate relatively at a high speed, the gland packing 20 is thus worn. The above-mentioned orifice function is properly exhibited without being damaged.

  Further, in a high-speed rotating device such as a centrifugal dehydrator, the bearings 13a and 13b may generate heat violently due to high-speed rotation of the rotation-side joint case 5, and there is a risk of heat loss. However, in the first rotary joint R 1, the second passage portion 11 that holds the inner peripheral portions of the bearings 13 a and 13 b constitutes the outer peripheral wall of the seal chamber 22, and is cooled by the sealing liquid 23 in the seal chamber 22. (Because it is water-cooled), the bearings 9 a and 13 b (and the bearings 9 a and 13 b (and the bearings 9 a and 13 b) are cooled by contact with the sealing liquid 23 in the sealing chamber 37. The heat generation of the oil seals 14a and 14b) is suppressed, and the life reduction due to heat loss is prevented as much as possible.

  Note that the effects and functions of the first rotary joint R1 described above are similarly exhibited when the slurry fluid 1 is used for applications in which the fluid 1 flows from the rotation side channel 3 to the stationary side channel 2. Needless to say.

  FIG. 5 is a longitudinal side view showing a second embodiment of a rotary joint according to the present invention. In this embodiment, a rotary joint (hereinafter referred to as “second rotary joint”) R2 includes bearings 13a, 13b ( And the same structure as the first rotary joint R1 described above except that the bearing portion 9 of the stationary joint case 4 holding the oil seals 14a, 14b) has a radiator structure by the coolant 23b. Of the constituent members in the second rotary joint R2, those having the same structure as the first rotary joint R1 are designated by the same reference numerals in FIG. 5, and the details thereof are omitted.

  That is, in the second rotary joint R2, as shown in FIG. 5, the bearing portion 9 of the stationary side joint case 4 holding the bearings 13a and 13b and the oil seals 14a and 14b is provided with the coolant 23b. A flowing cooling liquid passage 60 is formed to constitute a radiator structure for cooling the bearings 13a and 13b and the oil seals 14a and 14b. The coolant passage 60 is an annular space that is disposed at a position corresponding to the front bearing 13 a and is formed concentrically with the outer peripheral portion of the bearing portion 9. The sealing liquid (water) 23 in the sealing liquid chamber 37 is supplied to the cooling liquid passage 60 as the cooling liquid 23 b via the first to third communication paths 61, 62, 63 formed in the bearing portion 9. It has become. The second communication passage 62 is an annular passage formed at a position corresponding to the stationary sealing ring 45 of the second mechanical seal 41 and formed concentrically with the inner peripheral portion of the bearing portion 9. The communication path 61 communicates the sealed chamber 37 and the second communication path 62, and the third communication path 63 communicates the second communication path 62 and the coolant path 60. In addition, a discharge path 64 that communicates with the coolant passage 60 is formed in the bearing portion 9. The above-described sealing liquid discharge line 39a is connected to the discharge path 64, and the sealing liquid 23 (cooling liquid 23b) is circulated and flowed from the sealing liquid chamber 37 to the cooling liquid passage 60. That is, in the second rotary joint R <b> 2, the drainage passage 39 in the first rotary joint R <b> 1 includes the coolant passage 60, the communication passages 61, 62, 63, and the discharge passage 64. As shown in FIG. 5, the third communication passage 63 and the discharge passage 64 are opened facing the coolant passage 60 in the front-rear direction, but the partition provided in the coolant passage portion between the openings. 65 prevents a short path between the two paths 63 and 64. In this example, room-temperature water is used as the sealing liquid 23 or the cooling liquid 23b. However, if necessary, a cooling mechanism is provided in the circulation circuit composed of the sealing liquid supply line 38a and the sealing liquid discharge line 39a. The sealing liquid 23 discharged from the cooling liquid passage 60 and circulated and supplied to the sealing liquid chamber 37 can also be cooled.

  The second rotary joint R2 configured in this manner exhibits the same effects and functions as the first rotary joint R1, and further has a bearing portion 9 of the stationary joint case 4 that holds the bearings 13a and 13b. Since the cooling liquid 23b (water which is the sealing liquid 23) circulates and flows, the bearings 13a and 13b (and the oil seals 14a and 14a) are provided even when the rotation-side joint case 5 rotates at a high speed. Is sufficiently cooled and there is no risk of heat loss due to heat generation. Therefore, even when equipped in a high-speed rotating device such as a centrifugal dehydrator, durability is improved and a good joint function can be exhibited over a long period of time. Moreover, since the sealing liquid 23 is used as the cooling liquid 23b and the sealing liquid supply device and the cooling liquid supply device are used together, a system including a centrifugal dehydrator as compared with the case where both supply devices are provided separately. The whole can be simplified. Even in the first rotary joint R1 in which the coolant passage 60 is not provided, as described above, the bearings 13a and 13b are cooled by the seal liquid 23 in the seal chamber 22 and the seal chamber 37, but the second rotary joint R2 In this way, the bearing 9 has a water-cooled radiator structure, so that the cooling can be performed more effectively.

  FIG. 6 is a longitudinal side view showing a third embodiment of a rotary joint according to the present invention. A rotary joint (hereinafter referred to as “third rotary joint”) R3 in this embodiment is an annular seal member. The second rotary joint R2 has the same structure as that of the second rotary joint R2 except that a plurality of springs 66 are used as the clamping pressure application means of the gland packing 20 as described above. In addition, about each structural member in 3rd rotary joint R3 which makes the same structure as 2nd rotary joint R2, it attaches | subjects the same code | symbol in FIG. 6 and FIG. 7 which is an enlarged view of the principal part. The details will be omitted.

  That is, in the third rotary joint R3, as shown in FIGS. 6 and 7, a spring holding ring 67 is disposed between the packing pressing body 27 and the spring receiving portion 29, and a plurality of spring holding rings 67 are arranged on the spring holding ring 67. One spring 66 (only one is shown) is held. That is, the spring retaining ring 67 is fitted and fixed to the inner peripheral surface of the second passage portion 11 in a state of being abutted with the spring receiving portion 29, and is formed in an axially penetrating shape formed at equal intervals in the circumferential direction. The springs 66 are inserted and held in the plurality of spring holding holes 67a. Each spring 66 is inserted between the spring holding hole 67a and is loaded between the spring receiving portion 29 and the packing pressing body 27, and the packing pressing body 27 is connected to the first or second rotary joint R1, Like the spring 26 in R2, it is urged against the gland packing 20. The spring receiving portion 29 is formed with a communication hole 29a that communicates with each spring holding hole 67a. The spring holding ring 67 is prevented from rotating relative to the second passage portion 11 by engaging a pin 67 b projecting therefrom with an engagement hole 29 b formed in the spring receiving portion 29.

  In the third rotary joint R3 configured in this way, the packing pressing body 27 is pressed at equal intervals in the circumferential direction by the plurality of springs 66, so that the pressing force of the gland packing 20 by the packing pressing body 27 is not increased. Evenly, the clamping pressure of the gland packing 20 is more appropriately performed.

  The configuration of the present invention is not limited to the first to third rotary joints R1, R2, and R3 described above, and can be appropriately improved and changed without departing from the basic principle of the present invention.

  For example, in the first to third rotary joints R1, R2, and R3, the orifice 40 is formed in the stationary seal ring 31 that is the stationary side member of the first mechanical seal 21, but as shown in FIG. You may make it form. The position where the orifice 40 is formed is not particularly limited in terms of the orifice function as long as it is a stationary side member. However, in order not to cause a stagnation portion due to the sealing liquid 23, a sealing portion by the mechanical seal (first mechanical seal) 21 is used. It is preferable to make it a place that can be opened to the seal chamber 22 in the vicinity of.

  Further, in the first to third rotary joints R1, R2, and R3, the packing pressing body 27 is pressed and urged against the gland packing 20 by the springs 26 and 66, so that the clamping pressure of the gland packing 20, that is, the sealing force is changed to the spring. However, depending on the sealing conditions, the packing pressing body 27 is provided on the inner peripheral surface of the second passage portion 11 without providing the springs 26 and 66, as shown in FIG. It is also possible to adjust the clamping force (sealing force) of the gland packing 20 by the tightening force of the bolts 28 of the packing retainer 25 by engaging with the annular locking portion 68. On the other hand, when the springs 26 and 66 are provided, the springs 26 and 66 are arranged in a place where they are not in direct contact with the slurry fluid 1 as described above in order to prevent clogging due to the accumulation of the slurry fluid 1. It is preferable to keep it.

  In the first to third rotary joints R1, R2, and R3, the passage portion 11 of the rotation side joint case 5 is used as the second passage portion that constitutes the outer peripheral wall of the seal chamber 22, and the passage portion 8 of the stationary side joint case 4 is used. The first passage portion 8 that forms the inner peripheral wall of the seal chamber 22 is used, but the relationship between the passage portions 8 and 11 can be reversed. In other words, the passage portion 8 of the stationary joint case 4 is used as a second passage portion having a large diameter, and the passage portion 11 of the rotation side joint case 5 is used as a first passage portion having a small diameter that can be inserted into the passage portion 8. A seal chamber 22 may be formed between the inner peripheral surface of 8 and the outer peripheral surface of the passage portion 11. In this case, a bearing portion corresponding to the bearing portion 9 is provided in the rotation side joint case 5, and the bearings 13 a and 13 b (and the oil seals 14 a and 14 b are provided between the bearing portion and the passage portion 8 of the stationary side joint case 4. ).

  Further, the annular seal member 20 is not limited to the above-described gland packing, but the one that can control the leakage amount of the sealing liquid 23 from the annular seal member 20 by the orifice 40 and has excellent durability against high-speed rotation is used. It is preferable to do.

  Further, the rotary joint of the present invention is suitable for a rotary device such as a centrifugal dehydrator that handles slurry fluid having a high slurry concentration such as sewage sludge, manure sludge, etc. As long as (mixing of a small amount of sealing liquid) can be tolerated, it can be applied well to slurry fluids of any property including slurry fluids having a low slurry concentration, and its application is extremely wide.

It is a vertical side view which shows a 1st rotary joint. FIG. 2 is an enlarged detailed view showing a main part of FIG. 1. FIG. 3 is a detailed view showing another main part of FIG. 1 in an enlarged manner. It is a vertical front view of the principal part along the IV-IV line of FIG. It is a vertical side view which shows a 2nd rotary joint. It is a vertical side view which shows a 3rd rotary joint. FIG. 7 is a detailed view showing an essential part of FIG. 6 in an enlarged manner. It is a vertical side view of the principal part which shows the modification of the rotary joint which concerns on this invention. It is a vertical side view of the principal part which shows the other modification of the rotary joint which concerns on this invention.

Explanation of symbols

  R1 ... 1st rotary joint (slurry rotary joint), R2 ... 2nd rotary joint (slurry rotary joint), R3 ... 3rd rotary joint (slurry rotary joint), 1 ... Slurry fluid, 2 ... Static side flow path DESCRIPTION OF SYMBOLS 3 ... Rotation side flow path, 4 ... Stationary side joint case, 5 ... Rotation side joint case, 6 ... Fluid passage, 6a ... Stationary side fluid passage part, 6b ... Rotation side fluid passage part, 7 ... Sealing means, 8 ... 1st passage part (passage part of stationary side joint case), 9 ... bearing part, 10 ... flange part, 11 ... 2nd passage part (passage part of rotation side joint case), 12 ... flange part, 13a, 13b ... bearing , 14a, 14b ... oil seal, 20 ... gland packing (annular seal member), 20a ... packing part (seal with protrusions biting in) 21) 1st mechanical seal (mechanical seal for sealing the seal chamber), 22 ... Seal chamber, 23, 23a ... Sealing liquid, 23b ... Cooling liquid (sealing liquid), 24 ... Sealing liquid supply path, 25 ... Packing presser, 26... Spring (first mechanical seal spring), 27... Packing pressing body, 27 a... Projection, 29 .. spring receiving portion, 30 .. rotating seal ring (mechanical seal component provided on the rotating joint case) 31a ... Main body part of stationary seal ring, 31b ... Holding part of stationary seal ring, 37 ... Sealing liquid chamber, 40 ... Orifice, 41 ... Second mechanical seal, 60 ... Coolant passage.

Claims (6)

A rotary side joint case having a cylindrical passage portion connected to a rotation side flow path is connected to a stationary side joint case having a cylindrical passage portion connected to the static side flow path, as a first passage as one passage portion. In a state where the part is inserted concentrically into the second passage part which is the other passage part, it is rotatably connected around the axis of both passage parts to form a series of fluid passages penetrating through both passage parts,
An annular space sealed between the opposing peripheral surfaces of the two passage portions by an annular seal member filled between the opposing peripheral surfaces and a mechanical seal interposed between the joint cases and between the fluid passages. forming a seal chamber which is sealed by a member,
An orifice communicating with the seal chamber is formed in the stationary joint case or the mechanical seal component provided in the stationary joint case ,
Between the joint cases, an annular space closed by two mechanical seals including the mechanical seal and forming a sealed liquid chamber communicating with the seal chamber through the orifice;
In the stationary joint case, a liquid supply path for supplying a sealing liquid having a pressure higher than that of the slurry fluid flowing in the fluid passage and allowed to be mixed into the fluid to the sealing chamber is formed .
A rotary joint for slurry fluid, characterized in that the sealing liquid is supplied and filled from the orifice into the seal chamber. The mechanical seal that seals between the seal chamber and the liquid seal chamber is of the end surface contact type in which the stationary seal ring provided in the stationary joint case and the rotary seal ring provided in the rotary joint case are in relative rotational sliding contact. , to form pores communicating the seal chamber and the sealing liquid chamber into the stationary seal ring, the pores characterized that you have no said orifice, rotary joint slurry fluid according to claim 1 . The rotation side joint case has a second passage portion, and the stationary side joint case has a first passage portion and a cylindrical bearing portion concentrically surrounding the second passage portion. Is mounted between the opposed peripheral surfaces of the second passage portion of the rotary joint case and the bearing portion of the stationary joint case, and a coolant passage through which the coolant flows The rotary joint for slurry fluid according to claim 1 or 2, characterized in that is formed . Coolant passages have been communicated to the sealing liquid chamber, a part of the supplied sealing liquid is configured to feature the tare Rukoto as supplied to the coolant passage as a coolant to the sealing liquid chamber, 請 A rotary joint for slurry fluid according to claim 3. Both annular seal members are clamped in the axial direction by a packing presser attached to one passage portion and a packing pressing body disposed in the seal chamber and provided to be rotatable relative to the other passage portion. It is a gland packing filled between the passage parts, and the packing pressing body is provided with a protrusion that bites into the packing part that is in contact with the other passage part on the inner peripheral side part or the outer peripheral side part of the gland packing, It characterized that you have configured to sealing liquid is introduced between the gland packing and the other passage portion in a portion where the protrusion bites, claim 1, claim 2, claim 3 or The rotary joint for slurry fluid according to claim 4. It characterized that you use water as working liquid, according to claim 1, claim 2, claim 3, the claims 4 or rotary joint slurry fluid according to claim 5.