JP2017221897A - Centrifugal separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent abrasion by a centrifugally separated solid matter.SOLUTION: A centrifugal separator comprises a bowl, an annular groove part formed using a rib projecting from an outer peripheral surface of the bowl and extending in a circumferential direction of the bowl, a screw conveyor housed inside the bowl, and a casing rotatably housing the bowl and the screw conveyor and having a baffle extending in an annular shape on an inner peripheral surface. The rib has a notch-shaped part, and an abrasion resistant plate is detachably mounted in this notch-shaped part. The abrasion resistant plate has a plate groove part connecting to the annular groove part. A tip part of the baffle extends into the inside of the annular groove part and the plate groove part. The plate groove part has a smaller width than the annular groove part, and is has a greater height of a groove part bottom surface.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a centrifugal separator, and more particularly, to a wear countermeasure for preventing wear caused by a centrifuged solid substance.

  As a centrifuge for centrifuging a processed product in a solid-liquid mixed state, a fixed casing, a bowl disposed in the fixed casing, and a screw disposed in the bowl are provided. 2. Description of the Related Art A decanter that centrifuges a processed product into a solid and a separated liquid by rotating at a specific differential speed is known.

  In this type of centrifugal separator, for example, a slurry solution containing metal hydroxide particles or a slurry solution containing coal particles (that is, a slurry solution containing abrasive particles) is used to prevent wear caused by solids. Is required.

  6 is a cross-sectional view showing a part of the solid matter discharge end portion in the centrifugal separator disclosed in Patent Document 1, and FIG. 7 is an enlarged view of a part of FIG. Referring to FIG. 6, the centrifugal separator includes a casing 101, a bowl 102 rotatably accommodated in the casing 101, and a screw 103 rotatably accommodated in the bowl 102. A baffle 101 a is formed in an annular shape on the inner wall surface of the casing 101, and the baffle 101 a extends toward a flange 102 a provided at an axial end of the bowl 102.

  The solid matter containing the abrasive particles is discharged into the chamber 104 formed on the right side of the baffle 101a. Since the abrasive particles are likely to accumulate around the baffle 101a, there is a risk that the abrasive particles with the flange 102a accumulated during the rotation of the bowl 102 may cause sliding wear. Therefore, in Patent Document 1, as an anti-wear measure, annular extension portions 102b and 102c are provided at the upper end portion of the flange 102a, and the bottom surface of the recess 102d formed by these annular extension portions 102b and 102c is used as a wear-resistant member. A plug 105 is embedded. The plug 105 is fitted into an opening formed in the flange 102a, and is fixed by an adhesive such as an epoxy resin.

JP 57-19049 A

  However, in the above-described configuration, the region protected by the plug 105 is limited to the bottom surface of the recess 102d, and the inner side surfaces (that is, the inner wall surfaces of the annular extending portions 102b and 102c) cannot be protected from sliding wear. . Therefore, there is a possibility that the annular extending portions 102b and 102c of the flange 102a are worn at an early stage due to the abrasive particles that have entered the recess 102d.

  Further, when the flange 102a is slidably worn, it is necessary to remove the supply pipe 106 from the bowl 102 and to carry out the replacement work of the flange 102a after the bowl 102 is carried out of the casing 101. Costs and costs.

  Furthermore, during operation of the centrifugal separator, vibration is applied to the adhesive layer between the flange 102a and the plug 105, and the plug 105 may fall off in the axial direction.

  In order to solve the above-described problems, a centrifugal separator according to the present invention includes (1) a bowl, and an annular groove portion that is formed using a rib protruding from the outer peripheral surface of the bowl and that extends in the circumferential direction of the bowl. A centrifuge comprising: a screw conveyor housed in the bowl; and a casing that rotatably houses the bowl and the screw conveyor and provided with a baffle extending annularly on an inner peripheral surface thereof. The rib is formed with a notch-shaped portion, and a wear-resistant plate is detachably attached to the notch-shaped portion, and the wear-resistant plate is formed in the annular groove portion in the circumferential direction of the annular member. A plate groove portion to be connected is formed, and a tip end portion of the baffle extends inside the annular groove portion and the plate groove portion. Groove width than the annular groove is small and characterized by a high level of the groove bottom.

  (2) The notch-shaped portion includes a retaining slit that prevents the wear-resistant plate from coming off from the radial direction of the bowl, and the wear-resistant plate rotates the bowl with respect to the retaining slit. The centrifugal separator according to (1) above, wherein the centrifugal separator is inserted from an axial direction.

  (3) The centrifuge according to (2), wherein the retaining prevention slit has a dovetail structure.

  (4) The centrifugal separator according to any one of (1) to (3), wherein the wear-resistant plate is fixed by a bolt.

  (5) Any one of the above (1) to (4), wherein the notch-shaped portions are provided in at least two locations of the rib, and the intervals between the adjacent notch-shaped portions are substantially equal to each other. The centrifuge according to any one of the above.

  (6) Said (1) thru | or (5) characterized by the said baffle being a side wall of the solid substance receiving chamber formed between the said casing and the said bowl and receiving the solid substance discharged | emitted from the said bowl. ).

  (7) The centrifuge according to any one of (1) to (6), wherein the wear-resistant plate is made of a material having rigidity higher than that of the rib.

  According to the present invention, the wear spot due to the abrasive particles contained in the solid is concentrated on the wear-resistant plate, so that the rib (corresponding to the flange 102a of Patent Document 1) and the bowl can be protected from sliding wear. it can. Further, since it is not necessary to remove the rib from the bowl when exchanging the wear-resistant plate that has undergone sliding wear, the cost can be reduced while simplifying the exchanging operation.

  Furthermore, by providing a retaining slit in the notch-shaped portion, it is possible to suppress the wear-resistant plate from falling off from the radial direction of the bowl.

It is a schematic sectional drawing of a horizontal type decanter. It is an external view of the ring-shaped member seen from the rotating shaft direction of the bowl. It is an enlarged view in a part of ring-shaped member with which the impeller was mounted | worn. FIG. 4 is a view as viewed from an arrow E in FIG. 3. It is F arrow line view of FIG. It is sectional drawing which shows a part of solid discharge end part in the centrifuge disclosed by patent document 1. FIG. It is an enlarged view in a part of FIG.

  Hereinafter, a centrifuge that is a preferred embodiment of the present invention will be described by taking a horizontal decanter as an example. However, the technical scope of the present invention is not limited and interpreted by the embodiments described below. FIG. 1 is a front view of a decanter and a sectional view of a part thereof.

  The decanter 1 includes a bowl 10, a screw conveyor 20 disposed inside the bowl 10, and a casing 60 that rotatably accommodates the bowl 10 and the screw conveyor 20. The bowl 10 rotates around the rotation axis L indicated by a two-dot chain line. One end of the bowl 10 in the direction of the rotation axis L is supported to be rotatable with respect to the bearing 11, and the other end is supported to be rotatable with respect to the bearing 12.

  A plurality of separation liquid discharge ports 13 are formed at one end of the bowl 10 in the rotation axis L direction. A plurality of solid discharge ports 14 are formed at the other end of the bowl 10 in the direction of the rotation axis L. These solid discharge ports 14 are arranged around the rotation axis L of the bowl 10, and the intervals between the adjacent solid discharge ports 14 are set to be approximately equal. The opening shape of the solid discharge port 14 may be circular, for example.

  The other end side of the bowl 10 in the direction of the rotation axis L is constituted by a beach portion 15 having a conical cone shape. However, the present invention can also be applied to the bowl 10 having a constant inner diameter that does not have the beach portion 15.

  The screw conveyor 20 has a function of conveying a solid substance to which a centrifugal force is applied in the bowl 10 in the direction of the rotation axis L, and rotates with a relative differential speed with respect to the bowl 10. That is, the screw conveyor 20 is rotated at a lower rotational speed than the bowl 10 when power is transmitted from the gear box 30. As the gear box 30, for example, a planetary gear can be used.

  Screw blades 22 are spirally formed on the outer peripheral surface of the body portion 21 of the screw conveyor 20. A hollow portion (buffer portion) is formed inside the body portion 21, and this hollow portion serves as a processed material supply chamber 21 a for supplying a processed material, and an outer peripheral surface of the processed material supply chamber 21 a. A plurality of processed material passages 210a are formed in the.

  The supply pipe 40 passes through the pulley 31 for driving the bowl 10 and extends in the direction of the rotation axis L of the bowl 10, and one end forms a processed material introduction port 40 a outside the bowl 10, and the other end Forms a treated product supply port 40b inside the treated product supply chamber 21a.

  The treatment product introduced from the treatment product introduction port 40a is introduced into the treatment product supply chamber 21a through the supply pipe 40. The processed products include various solid-liquid mixtures that can be separated into solid and liquid by centrifugation. The present invention is applied to processing liquids containing abrasive particles such as metal hydroxide particle-containing slurry and coal particle-containing slurry liquid. Are particularly suitable.

  A plurality of baffles 61 to 63 are provided on the inner peripheral surface of the casing 60, and these baffles 61 to 63 are arranged in this order from the solids discharge side to the separation liquid discharge side. Of these baffles 61 to 63, the baffle 61 corresponds to the baffle described in claim 1. A receiving chamber A for receiving solid matter discharged from the solid discharge port 14 is formed inside the casing 60. The receiving chamber A is mainly formed with the baffle 61, the casing 60, and the beach portion 15 as wall portions. That is, the baffle 61 forms the side wall of the receiving chamber A.

  A ring-shaped member 70 (corresponding to the rib described in claim 1) extending in the circumferential direction is provided on the outer peripheral surface of the bowl 10, and this ring-shaped member 70 is attached to a flange member (not shown) in the direction of the rotation axis L. It is fixed against.

  Next, the ring-shaped member 70 will be described with reference to FIGS. FIG. 2 is an external view of the ring-shaped member viewed from the direction of the rotation axis L of the bowl. However, the lower half of the ring-shaped member and the impeller are omitted in the drawing. FIG. 3 is an enlarged view of a part of the ring-shaped member to which the impeller is attached. 4 is a view taken in the direction of arrow E in FIG. FIG. 5 is a view taken in the direction of arrow F in FIG.

  The ring-shaped member 70 is provided at a position corresponding to the baffle 61 and can be made of, for example, stainless steel. On the outer peripheral surface of the ring-shaped member 70, a single annular groove 70a extending in the circumferential direction is formed. The annular groove portion 70 a is formed at the approximate center in the direction of the rotation axis L of the ring-shaped member 70. 2, 3, and 5, the annular groove portion 70 a is illustrated with a dotted line.

  The ring-shaped member 70 is formed with two notch-shaped portions 71 penetrating in the direction of the rotation axis L (however, one notch-shaped portion 71 is not shown) at an interval of about 180 degrees. The notch-shaped portion 71 includes a retaining slit 71a and a bolt fastening hole 71b. The retaining slit 71a includes a pair of tapered surfaces 711a and a bottom surface 712a connecting the lower ends of the tapered surfaces 711a.

  The tapered surface 711a is formed so as to gradually expand from the outer diameter surface of the ring-shaped member 70 toward the inner diameter surface. The bolt fastening holes 71b are formed in the bottom surface 712a of the notch-shaped portion 71, and are provided by the number of bolts 75 described later.

  An impeller (corresponding to a wear-resistant plate) 5 is detachably attached to each notch-shaped portion 71. The impeller 5 is made of a material having rigidity higher than that of the ring-shaped member 70. For example, Igetalloy (registered trademark), which is a cemented carbide, can be used.

  The impeller 5 includes a pair of impeller tapered surfaces 5a and 5b, an impeller bottom surface 5c, an impeller short vertical surface 5d, an impeller long vertical surface 5e, an impeller top surface 5f, and an impeller groove portion (plate groove portion) 5g, and is provided with respect to a retaining slit 71a. Can be inserted and removed from the direction of the rotation axis L. The pair of impeller taper surfaces 5a and 5b are in contact with the pair of taper surfaces 711a of the retaining slit 71a when the impeller 5 is mounted. In this manner, the retaining slit 71a is configured by the tapered surface 711a and the fixing structure of the impeller 5 is a dovetail structure, so that the impeller 5 can be prevented from falling off from the radial direction of the ring-shaped member 70. That is, even if the bolt 75 described later is loosened and removed due to vibration during centrifugation, the impeller 5 can be prevented from falling off.

  The impeller short vertical surface 5d and the impeller long vertical surface 5e extend in a direction substantially perpendicular to the outer peripheral surface of the ring-shaped member 70, and the impeller short vertical surface 5d is formed shorter than the impeller long vertical surface 5e. The impeller top surface 5f is formed at a position connecting the upper end portions of the impeller short vertical surface 5d and the impeller long vertical surface 5e, and is positioned above the head of the bolt 75. That is, the bolt 75 is accommodated in the opening of the impeller 5 so as not to protrude from the impeller top surface 5f. Thereby, it can suppress that the head of the volt | bolt 75 carries out sliding wear by the solid substance deposited on the casing 60. FIG. An opening for inserting a fastening tool (for example, a wrench) is formed in the head of the bolt 75. When this opening is cut by sliding wear, the replacement work of the bolt 75 becomes complicated. According to the present embodiment, since the bolt 75 is protected from sliding wear, when the impeller 5 is subjected to sliding wear, the bolt 75 is simply removed using a fastening tool, and the impeller 5 can be easily replaced. be able to.

  Further, the impeller top surface 5f is inclined by a difference in length between the impeller short vertical surface 5d and the impeller long vertical surface 5e. As described above, when the impeller top surface 5f is formed in a tapered shape, the contact portion of the solid matter is limited to the vicinity of the top portion 5f ′ having the highest height among the impeller top surfaces 5f. On the other hand, when the impeller top surface 5f is formed in a flat shape, the entire impeller top surface 5f is in surface contact with the solid matter, so that the frictional force increases, and the bowl 10 rotates while resisting this large frictional force. Therefore, power consumption increases. According to the configuration of the present embodiment, since the contact between the solid matter accumulated in the casing 60 and the impeller 5 becomes a point contact, the frictional force is reduced, and an increase in power consumption can be suppressed. Moreover, since the frictional heat is reduced by making the contact with the solid matter a point contact instead of a surface contact, the impeller 5 can be prevented from being overheated.

  Further, by providing the impeller short vertical surface 5d on the upstream side of the impeller long vertical surface 5e in the rotation direction of the bowl 10, the impeller top surface 5f is gradually inclined from the upstream to the downstream in the rotation direction. Is going to be higher. When the impeller top surface 5f is inclined in the opposite direction (that is, when the inclination direction of the impeller top surface 5f is a direction in which the height gradually decreases from upstream to downstream in the rotation direction), the top portion 5f There is a possibility that the solid material scraped by the point contact with ′ is pressed against the impeller top surface 5f by the solid material around the impeller 5 and the opening of the impeller top surface 5f is filled. On the other hand, in this embodiment, since the shaved solid substance falls in the said rotation direction of the impeller 5, it can suppress that it is pressed on the impeller top surface 5f.

  One end of the impeller top surface 5f in the longitudinal direction is formed in an arcuate shape, and the other end is formed in a U shape bent at 90 degrees. The impeller bottom surface 5c is in contact with the bottom surface 712a of the retaining slit 71a when the impeller 5 is mounted.

  The impeller groove portion 5g is formed at a position connected to the annular groove portion 70a in the circumferential direction of the ring-shaped member 70. Here, as shown in FIG. 5, the width of the impeller groove 5g (in other words, the dimension of the impeller groove 5g in the direction of the rotation axis L) is T1, and the width of the annular groove 70a (in other words, the annular groove in the direction of the rotation axis L). The width T2 is larger than the width T1 when the dimension 70a) is T2. Further, the bottom surface of the impeller groove portion 5g is formed at a position higher than the bottom surface of the annular groove portion 70a. That is, the bottom surface 51 of the impeller groove portion 5g is provided at a position closer to the impeller top surface 5f than the bottom surface of the annular groove portion 70a when viewed in the normal direction of the paper surface of FIG. The reason why the sizes of the impeller groove portion 5g and the annular groove portion 70a are set in this way will be described later.

  On the impeller top surface 5f, openings for inserting bolts 75 are formed at positions sandwiching the impeller groove 5g. These bolts 75 pass through the impeller 5 and are fastened to the ring-shaped member 70. . Thereby, the impeller 5 can be more firmly fixed. Moreover, the impeller 5 can be easily removed simply by releasing the fastening by the bolt 75 and pushing out the impeller 5 in the direction of the rotation axis L.

  Here, as shown in FIG. 1, the front end portion of the baffle 61 extends toward the inside of the annular groove portion 70 a of the ring-shaped member 70 and the impeller groove portion 5 g of the impeller 5, and these annular groove portion 70 a and impeller A slight gap is formed between the groove 5g and the tip of the baffle 61. However, the gap between the baffle 61 and the impeller groove portion 5g is set to be smaller than the gap between the baffle 61 and the annular groove portion 70a.

  Next, the behavior of the centrifuged solid material will be described. The centrifuged solid matter is discharged from the solid discharge port 14 to the receiving chamber A as described above. This solid matter is easily deposited on the inner surface of the casing 60 around the impeller 5, and this deposit grows and contacts the impeller 5 as the centrifugal separation proceeds. Here, when the treated product is nickel hydroxide, mist-like nickel is deposited on the casing 60, and this deposit contains a lot of moisture immediately after being deposited on the casing 60, but is gradually dehydrated and hardened. To do.

  In the present embodiment, sliding wear due to hard particles is made by making the width T2 of the annular groove portion 70a larger than the width T1 of the impeller groove portion 5g and providing the bottom surface of the impeller groove portion 5g higher than the bottom surface of the annular groove portion 70a. Is concentrated in the impeller groove portion 5g. Thereby, the ring-shaped member 70 and the bowl 10 provided separately from the impeller 5 can be protected from sliding wear.

  This effect is more easily obtained by installing the impeller 5 in at least two places in the circumferential direction of the ring-shaped member 70.

  Here, when the bolt 75 is loosened and dropped due to vibration during centrifugation, the impeller 5 may be detached from the ring-shaped member 70 due to the centrifugal force of the bowl 10. However, in this embodiment, since the impeller 5 is slid into the retaining slit 71a to restrict the movement of the bowl 10 in the centrifugal force direction, the impeller 5 can be prevented from coming off.

  When the sliding wear of the impeller 5 further proceeds, it is necessary to stop the decanter 1, remove the impeller 5 from the ring-shaped member 70, and then replace it with a new impeller 5. This removal operation can be performed simply by releasing the fastening of the bolt 75 and pushing out the worn impeller 5 in the direction of the rotation axis L.

  Here, when the impeller 5 is not provided, the ring-shaped member 70 is slidably worn by the hard particles, so that the entire ring-shaped member 70 needs to be replaced. This replacement operation can be performed only after the supply pipe 40 and the like are removed from the bowl 10 and the bowl 10 is carried out of the casing 60. Therefore, the replacement work takes time and costs increase. On the other hand, in this embodiment, since it is only necessary to replace the impeller 5 that has been worn by sliding, the replacement work is easy and the cost can be reduced.

(Modification 1)
In the above-described embodiment, the retaining slit 71a has a dovetail structure, but the present invention is not limited to this, and other structures that can prevent the impeller 5 from falling off in the radial direction of the bowl 10 (for example, a sickle joint structure). ) Can also be adopted.

(Modification 2)
In the above-described embodiment, the “rib” is formed by assembling the ring-shaped member 70 formed with the annular groove 70a on the outer peripheral surface of the bowl 10, but the present invention is not limited to this, and the two annular ribs are rotated. An annular groove portion may be formed by assembling the outer peripheral surface of the bowl 10 with a gap in the direction of the axis L. In this case, an annular groove is formed by a gap formed between these annular ribs.

DESCRIPTION OF SYMBOLS 1 Centrifugal separator 5 Impeller 5a, 5b Impeller taper surface 5c Impeller bottom surface 5d Impeller short vertical surface 5e Impeller long vertical surface 5f Impeller top surface 5g Impeller groove part 10 Bowl 20 Screw conveyor 60 Casing 61 Baffle 70 Ring-shaped member 70a Annular groove part 71 Shape part 71a Retaining slit 71b Bolt fastening hole 75 Bolt

Claims (7)

Bowl and
An annular groove formed with ribs protruding from the outer peripheral surface of the bowl and extending in the circumferential direction of the bowl;
A screw conveyor housed inside the bowl;
A casing in which the bowl and the screw conveyor are rotatably accommodated, and a baffle extending in an annular shape is provided on an inner peripheral surface;
A centrifuge having
The rib has a notch-shaped part, and a wear-resistant plate is detachably attached to the notch-shaped part.
The wear resistant plate is formed with a plate groove connected to the annular groove in the circumferential direction of the annular member,
The tip of the baffle extends inside the annular groove and the plate groove,
The plate groove part is smaller in width than the annular groove part, and the height of the bottom face of the groove part is high. The notch-shaped portion includes a retaining slit that prevents the wear-resistant plate from coming off from the radial direction of the bowl,
2. The centrifugal separator according to claim 1, wherein the wear-resistant plate is inserted into the retaining slit from a rotation axis direction of the bowl.   The centrifuge according to claim 2, wherein the retaining prevention slit has a dovetail structure.   The centrifuge according to any one of claims 1 to 3, wherein the wear-resistant plate is fixed by a bolt.   The notch shape part is provided in at least two places of the rib, and the interval between the adjacent notch shape parts is substantially equal to each other. Centrifugal device.   The said baffle is a side wall of the solid substance receiving chamber formed between the said casing and the said bowl and receiving the solid substance discharged | emitted from the said bowl, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. The centrifuge according to one. The centrifuge according to any one of claims 1 to 6, wherein the wear-resistant plate is made of a material having rigidity higher than that of the rib.