FR2468763A1 - TWO-STAGE ROTARY APPARATUS FORMING CENTRIFUGAL PUMP OR RELAXING TURBINE - Google Patents

Abstract

The invention relates to a rotary apparatus forming both a centrifugal pump and an expansion turbine. It relates to an apparatus comprising a housing 34, inlets 12 and outlets 30, a volute 14 in each stage, end plates 38 and a shaft 15 carrying centrifugal wheels 20. The two stages are mounted back to back. . The pump allows the circulation of very corrosive suspensions. Application to the pumping of coal suspensions.

Description

The present invention relates to centrifugal pumps

  fuzes and expansion turbines, and more specifically rotary machines forming centrifugal pumps and expansion turbines operating at high temperature, at high pressure and with high volume flow rates, of the type used in the chemical industries and in power plants. Coal liquefaction operations, the industrial development of which is currently under consideration, require a suspension feed system.

  coal with a high capacity and operating at almost

  high level. An extrapolation of the alternative power supply pumps currently used to provide the desired high capacity requires a large number of devices with correspondingly large investment and maintenance costs. In another perspective, the high volume centrifugal pumps appear

  ability to provide the high capacity needed for

  liquefaction of coal. However, the pumps

  centrifuges must be carried out so that they function

  at high speed so that they give the

  high voltage required and may be subject to wear

  excessive internal pressure due to the high speeds of

  sions. A thorough study of the prior art

  shows that centrifugal pumps of the most common type

  used for pumping liquid and solids mixtures is a single-stage unit

  at low speed and at low pressure. In some

  several series of devices have been mounted in series.

  designed to give high pressures.

  When using with suspensions of

  coarse materials the solids of which may

  to dye 65 mm, the wheels of the pumps are made with large widths of passage between the fins and with significant thicknesses. The wheel generally has a bandage and operates with a large clearance relative to the casing. The front and rear tires of the wheel have integral discharge fins which reduce the recirculation

  in order to reduce abrasion wear in

  free space and that leaks or accumulations of

  solid substances are minimal. Hard metals such as the "Ni-hard" alloy as well as

  cast iron coated with soft rubber. In some applications

  mining operations or dredging, the pumps at-

  dyes a pressure of 3.5.105 to 5.25.10 Pa, when the wheels turn with a speed of the ends of the vanes between 18 and 26 m / s. For a given speed of the tip of the fins necessary to obtain a certain

  pressure, the use of a large-diameter wheel

  low speed is preferable for obtaining a low speed of circulation of the suspension and a

  long service life of the pump subjected to wear.

  In the case of applications of fine suspensions, having for example solids whose

  dimensions are between 0.04 and 1.7 mm, we used

  single-stage and higher-speed pumps in chemical processing operations. The wheels have bandages, the clearance left between the wheels and the crankcase is lower, and the gaskets and the wear ring are cleaned by clean fluids. Commonly used materials are austenitic stainless steel, a nickel-based hard alloy "Ni-hard", white cast iron and high chromium steel. Silicon carbide coating giving good combined strength

  corrosion and erosion. The concentrations of

  The pensions used in the chemical treatments are between 5 and 15% by weight, but these same pumps have been used for coal suspensions in an oil having a concentration of up to 40% (by

  example in the SRC factory in Wilsonville, United States of America

  America). These pumps give pressures of the order of 106 Pa, and they operate with a speed of the ends

fins of the wheel of 43 m / s.

  The centrifugal pump for suspension according to the in-

  vention is intended to function in the form of a tur-

  hydraulics of relaxation receiving a suspension, when

  that the current flowing in the pump changes direction. The turbine transforms a fluid at high pressure so that it

  take a lower pressure and thus transform the energy

  Kinetic kinetics of fluid in rotation energy. When the pressure decreases in the turbine, the gases contained in the

  fluid are released and extracted from the system by any

suitable.

  The hydraulic turbine can be used in any operation in which a control valve of one

  flow rate is used to lower the pressure

  high voltage of a current at a lower value. In con-

  sequence, a hydraulic turbine can replace

  high-pressure flashers commonly used in a coal liquefaction plant or in a geothermal energy recovery facility and

  geomechanics. In a liquefaction plant

  well, relief valves are used for reducing

  elevated pressure and temperature liquid coal in the reactor to form a lower pressure liquid coal in the filter feed tank, before further processing in a vacuum tower (for forming refined solid coal) or in a fractionation column (to form a fuel

  oil or a distillation fuel). In an installation

  geothermal and geomechanical energy recovery, the expansion valve is used directly at the wellhead for the recovery of methane dissolved in the

  high pressure brine in suitable tanks.

  When using the centrifugal pump of

  suspension as a hydraulic expansion turbine of sus-

  instead of high-pressure relief valves

  it has two important advantages: (1) the

  severe erosion caused by the valves is sup-

  awarded because of the progressive pressure and velocity changes obtained in the hydraulic turbine and (2)

  the potential energy of the high-pressure current is recovered

  in the form of useful power on the tree of tur-

  hydraulic power. In addition, the extension of the service life and the energy recovery provided by tur-

  the hydraulic system give a lower cost than the

  relaxing popes, when using.

  The problems posed by pumps and turbines

  of suspension of known types are the following

  (a) the erosion of the casing and wheel (or

  impeller rotor), a problem partially solved by increasing the

  the thickness of the walls, by hardening of the surfaces, by the application of resistant coatings, by

  maintaining low speeds, by removing the discon-

  and (b) the problems of settlement and grinding in gap spaces between the parts, these problems being solved in part by increasing these spaces and by installing expulsion members,

  (c) problems of wear of

  have been partially resolved by the use of organs

  expulsions, deflectors and circulation devices

fluid flow,

  (d) the problems posed by the shock and the abra-

  spikes, partially solved by hardening

  surfaces, maintaining low fluid velocities and

  resilient coatings, and (e) excessive wear of the wear rings, partially solved by use of a circulation device

  fluid and by important games.

  The invention relates to a centrifugal pump oper-

  at high temperature and pressure and with a

  high volume bit for the chemical industry. The

  pump according to the invention has been developed for the industrial

  sorting of the coal treatment in which suspensions

  coal, which may contain up to 50% of

  about ticular, must be transported. However,

  the pump according to the invention is suitable for other applications

  centrifugal pumps which are therefore part of the

  of the invention. More specifically, the two-stage centrifugal pump according to the invention comprises a pump housing and at least one pair of inlets and outlets

  for loading and unloading each stage of the pump.

  Inputs and outputs are placed across the periphery

  the pump so that they allow for a di-

  rect. Pre-curved vanes are arranged along the inner wall of the pump casing and carry fluid from the inlet

  to the wheel while reducing the relative speed

  tive at the entrance of the wheel and especially at the end of the inlet of the fins of the wheel. Two wheels placed face to face along the shaft of the pump, are intended to increase the kinetic energy of the fluid while transferring it to a radial diffuser without fins. This diffuser then reduces the speed of the fluid and increases its pressure because of its increasing volume. The fluid from the diffuser is conveyed in a change of directional scroll also for increasing the pressure of the fluid while also eliminating the secondary currents of the fluid.

  which could increase losses in the

  tallation. A replaceable nozzle is placed between the diffuser and the volute so that it channels the fluid to the volute and finally, a hydrostatic seal against the suspension is mounted coaxially along the pump shaft. to prevent leakage of the primary fluid

  from the inside of the pump to the outside

  which is at atmospheric pressure.

  When the flow direction of the fluid of the centrifugal pump is reversed, the apparatus constitutes an expansion turbine according to the invention. When the apparatus is operating in a turbine, the discharge pipe of the pump becomes the intake of the turbine, the aforementioned volute becomes the convergent spiral of turbine, the nozzle becomes the transition guide, the radial diffuser without fins becomes the inlet nozzle radial turbine without

  fins, the pump wheel becomes the rotor of the tur-

  First, the pre-bending fins become the righting guide vanes and direct the flow of fluid to the inlet volute of the pump which becomes the discharge spiral of the turbine. When the fluid leaves the discharge spiral, it is transported by

  a crossing duct to the admission of the second tur-

  and follows a similar path in this second stage.

  Thus, the invention relates to a rotary apparatus

  centrifugal pump and expansion turbine, function-

  at high pressure and temperature and with

  high volume, which can be used in the case of

  very abrasive place and having a high pressure.

  The invention also relates to a rotating apparatus forming a centrifugal pump and an expansion turbine which enables

  handling extremely abrasive materials.

  It also relates to a rotating apparatus forming a centrifugal pump and expansion turbine, having a high efficiency. It also relates to a rotary apparatus forming a centrifugal pump and expansion turbine in which the

thrusts are balanced.

  It also relates to a centrifugal pump that can be driven from one side or the other and an expansion turbine that can provide motive power on one side

or the other.

  It also relates to a two-stage rotary apparatus forming a pump and an expansion turbine, the two stages

  can be mounted in series or in parallel.

  It also relates to a rotary apparatus with two

  stages forming pump and expansion turbine, having a cross

externally.

  It also relates to a rotating apparatus forming a centrifugal pump and expansion turbine posing problems

very reduced maintenance.

  It also relates to a rotating apparatus forming centrifugal pump and expansion turbine having replaceable elements. It also relates to a rotary apparatus forming a pump and an expansion turbine operating at a pressure and a time

  high temperatures, giving satisfaction in

chemical treatment.

  Other features and advantages of the

  will become apparent from the following description,

  with reference to the accompanying drawings in which: Figure] & is a perspective view with torn parts of a two-stage centrifugal pump used for the transmission of a suspension; Figure 1b is a sectional view of the inlet of the centrifugal pump along line 1b-1b of Figure 3a; Figure 1c is a sectional view of the centrifugal pump outlet along line 1c-1c of Figure 3a; Figure 2a is an end view, with torn parts, of the two-stage centrifugal pump used for suspension feed; Figure 2b is a top view of the centrifugal pump of Figure 2a, showing the two inputs and the two outputs placed peripherally on the main housing of the pump; Figure 3a is a section of the centrifugal pump in a vertical and axial plane passing through the center of the two-stage centrifugal pump; Figure 3b shows in enlarged form an upper left portion of Figure 3a; Figure 4a is a perspective with parts torn from the change of direction;

  Figure 4b is a section along line 4b-

4b of Figure 4a;

  FIG. 4c is a section along line 4c-

  4c of Figure 4a; Figure 4d is a partial perspective of the volute and the beak; Fig. 5 is a perspective with torn parts of a two-stage expansion turbine; Figure 6a is a perspective with parts

  torn from the convergent spiral of change of direction

tion; -

  Figure 6b is a section along line 6b-

6b of Figure 6a;

  Figure 6c is a section along the line 6c-

  6c of Figure 6a; Figure 6d is a partial perspective of the convergent spiral and the transition guide; and FIGS. 7a and 7b on the one hand and 8a and 8b on the other hand are speed diagrams corresponding to the wheel of the pump on the one hand and to the rotor of the turbine

on the other hand.

  In FIGS. 7a to 8b, the reference C designates the absolute speed, the reference Cm the southern speed, the reference Cu the tangential component of the absolute speed, the reference W the relative speed, the reference Wu the tangential component of the relative speed. , the reference-U1 the speed of the ends of the fins at the entrance of the wheel, the reference U1 the speed of the tip of the fins

  at the turbine rotor inlet, the reference U2 the

  the end of the fins at the discharge of the wheel and the

  reference U2 the speed of the tip of the fins to the

  turbine, the speeds being indicated in m / s.

  In addition, these figures indicate that, in the case of

  pump wheel, the front edge of the fins is

  rounded and the tapered posterior edge while the arrangement is reversed in the case of the turbine rotor of FIGS. 8a

and 8b.

  In an advantageous embodiment, the invention

  The invention relates to a rotary apparatus in the form of a two-stage centrifugal module which can operate under very severe conditions. These conditions are pressures

  and high temperatures, a high volume flow and a half

  place capable of causing extensive erosion. We consider

  first dies the rotary apparatus in its application of

  pump, with reference to Figures la-4d and 7a-7b, re-

  identical ferences representing similar elements on the different drawings. These figures therefore represent a two-stage centrifugal pump used as feed for a suspension. It should be noted that the two stages placed face to face in the pump operate in the same way. Figure la is a perspective with torn parts of the pump 10 in which a fluid flows into the module 10 through the inputs 12 and in volutes 14 input. From these, the fluid is transported between vanes 16 prior bending so that the relative speed of entry of the end 18

  fins at the entrance of the wheel is reduced. Have them-

  pre-curving letters are intended to reduce the wear rate by erosion at the entrance of the wheel and

  essentially at the entrance end of the wheel,

  the order of 2, so that the useful life can be

  increased by 100%. These pre-curving fins as-

  know this increase in duration in many ways.

  First, the section of the inlet volute is reduced if

  although the relative velocity of the fluid transmitted to the

  the previous curvature is maintained. This vane deflects the fluid in the direction of rotation of the wheel and thus reduces the relative speed of the fluid transmitted to the wheel 20. Next, the pre-curving reduces the load applied to the blades of the wheel and thus reduces the

  number of blades required while allowing the use of

  thicker blades, so that the useful life is increased. The pre-curving also reduces wheel wear by allowing the use of a blade angle,

  side of the wheel, which corresponds to an orientation

  more radial and thus reduces the force of matter

  particle acting on the surface of the blades. Finally, the

  preliminary curvation reduces the diffusion of the wheel (W2 / W1)

  which reduces the current separation and the secondary currents

  Possible dams that normally appear between the pressure side and the suction side of the circulation passage and create eddies in the corners, causing localized erosion. Figure lb is a

cutting of the pump inlet.

  The fluid, when it leaves the pre-incision portion of the pump 10, flows into the wheel 20 in which its kinetic energy increases. The wheel has bandages to reduce spaces at the tip of the blades, reducing secondary currents that cause erosion and speed

  uniform delivery to the broadcaster without

  slacks. The fluid then exits through the outlet end 22 of the wheel 20 to a radial diffuser 24 without fins which is intended to reduce the speed of the fluid and to increase its pressure when the volume of the diffuser 24 increases. The reduction in fluid velocity reduces the speed of wear of the volute nozzle by erosion by a factor equal to 3. The fluid is directed from the radial diffuser 24 by the nozzle 26 (FIGS. 1c, 4a, 4c and 4d) to a change of direction volute 28 (FIGS. 4a to 4d) in which the pressure increases and the fluid is finally guided towards the exit

  30. The volute 28, combined with the spout 26, is

  presented more precisely in FIGS. 4a to 4d. The exa-

  careful mentions that the section of volute 28 aug-

  nozzle 26 at the outer outlet 30 and that the volute is placed asymmetrically with respect to the end of the diffuser 24. It should be noted that in this configuration

  advantageously, an external output 30 plays the role of a different

  secondary fuser which has a frustoconical shape. The fluid of the external outlet 30 can be transmitted by a

  external duct 32 to the second floor placed in the

  dule 10, so that it is connected in series, or can be transmitted to an external location so that the stages of the pumping module 10 can be connected in parallel. It should be noted that although the module was

  described with reference to a two-stage pump, it

  comes as well to single or multi-level modules.

  According to the criteria for the pump, the

  housing 34 may be formed of any material having a

  high mechanical strength that can be used in practice, and

  can be molded with virtually any thickness

  walls. It should be noted that the housing 34 of the pump also includes the body of the pump. However, given the severity of the criteria imposed on the pump according to the invention, the housing 34 may be formed of molded ductile steel, for example of the ASTM-216 G.R.WCB type, with a

  average wall thickness of about 5 cm.

  The main housing 34 of the pump is completed by plates forming end caps. These plates 38 contain many functional elements that are necessary for the support and the tight closure

  of the module 10 of the centrifugal pump. The functional elements

  3a are the ball bearing of the shaft holder, having a seal 42 enclosing a lubricant, the double mechanical seal 45, and the hydrostatic primary seal assembly 46 with respect to the suspension. This primary assembly 46 and the seal 44 formed between the stages are described in more detail in the French patent application No. 80.02830 filed by the Applicant. It should be noted that the functional elements must be identical and that their assembly must be the same in the two plates 38 forming lids. Each of the indicated elements can be removed from the plate 38

  without removing the plate itself from the pump 10. However,

  In an advantageous embodiment of the invention, the plate 38 can be disassembled with the elements assembled inside, after removal of the casing 48 from the bearing and

  of the bearing nut 50.

  - The different rotating elements are stacked,

  from each end 52 of the shaft to a shoulder-

  54 which is in the middle of the main shaft 56 so that the inside of the pump is accessible from both

  sides without the other side being affected.

  The wheels 20 are mounted on the main shaft

  56 so that they are face to face. The operation is

  partly because the entrance 12 of the two floors makes

  part of the main casing 34. The two wheels 20, ex-

  axial thrusts in opposite directions, ensure the equi-

  liberation of the rotary assembly relative to the fixed parts

  of the pump 10. Although any material of mechanical resistance

  The main shaft, in an advantageous configuration, is formed of alloy steel No. 4,340 and the fitted elements, comprising the wheel, are formed from alloy A-286, tungsten carbide, or aluminum alloy. alloy steel No. 4,341 or 4,330. Two sleeves mounted on

  the pile fixed on the shaft are preferably formed from

  A-286 bonding which is refractory and resists corrosion.

  This feature is chosen so that the differences

  of thermal dilatation of the tree and the different elements

  mounted on the sleeves are compensated and that the stack remains sealed between ambient temperature and an operating temperature of about 2900C. It should be noted that the pump according to the invention can

  be carried out so that it operates at ambient temperature

  ature. In this case, thermal expansion is not a problem and any other suitable material can be chosen. Ball bearings 40 are also part of the rotary assembly. They are placed at both ends of the shaft 56 and tightened by a nut 50. These main elements which rotate, with the shaft 56 and the wheels 20, must be as carefully balanced during the

  manufacture so that wear is not excessive.

  Each external input 12 is intended to trans-

  carrying the fluid from the outside of the pump housing to a device for circumferentially directing the fluid stream. Although any guiding device may be used, a plurality of precurve fins 16 formed along the inner wall of the pump housing 34 are advantageous for curving the fluid stream in the direction of rotation of the wheel, with reduction of the speed relative to the inlet end of the wheel and thus reducing the erosion of the ends of the inlet vanes of the wheel by abrasion. Although the pre-bending fins 16 may be formed in one piece along the inner wall of the pump housing, it is advantageous that they be molded

  separately so that they are removable and replaceable.

  Although any material having good wear resistance may be used for molding the pre-bending fins 16, the molded white cast iron is the

  most advantageous material. This white cast of

  The coating can then be surface-treated with an agent which increases its hardness, for example a coating of boride or tungsten carbide. This protection of the fins 16

  curvature increases the longevity of these.

  In addition, in one variant, inlet scrolls can

  can be placed between the outer inlet 12 and the fins 16 of curvature. These volutes 14, like the

  fins 16, facilitate the reduction of the speed of

  and promote the action of the fins 16 as they adjust the velocity of the fluid to the speed of the end of the inlet vanes of the wheel, so that the erosion to

  the entrance to the wheel and essentially at the end of 18

  the wheel is significantly reduced.

  The wheels 20 of the pump, in both stages and for all modules, have the same basic shape; however, it should be noted that the left and right wheels are symmetrical to each other. Although the wheels 20

  may be formed of any material of mechanical resistance

  high density, the white cast iron is advantageous

  given its extreme hardness and elasticity

  male. However, this material does not allow the wheel to support its own torque in the case of a normal shaft coupling, Accordingly, a reported hub formed of modified steel 4,330 is preferably brazed into the hub during the making. The insert and the wheel

  form a single piece after soldering connection.

  The surface 62 of the wear ring of the tire wheel, em-

  fishing a flow in the opposite direction of the end of the wheel at the entrance of it, is extremely sensitive

  wear and usually constitutes the region of

  initial launch of the wheel in the case of conventional suspension pumps. The wear ring of the wheel and the complementary fixed ring 64 are therefore advantageously formed of K-703 tunsgene carbide giving a long duration of use. The ring 62 of tungsten carbide

  is mounted on the wheel 20 by means of a partial ring

* threaded fixture fixed by narrowing, and it is purged by

a clean fluid at high pressure.

  The radial diffusion of the fluid stream during

  that it leaves the wheel 20 requires a circumferential channel of sufficient length for the speed of the current to be suitably reduced from 36 to 21.3 m / s before entering the volute 28. ' The radial diffuser 24 has two parallel walls, an inner liner 66 and an outer liner 68, as well as the discharge port of the wheel. The diffuser walls are formed by two inserts made of cast iron plates

very hard white.

  Wear is expected to be severe in the region

  of the diffuser because of the high speed of the suspension

  if we. Consequently, the surfacing of the surfaces of the

  although it is only possible, it is advantageous. In addition, given the erosion problems posed by the device, it is preferable that the diffuser does not have fins. The plates of the diffuser are held in position by the casing 34 of the pump, the inserts 70 and 72 of the volutes and the plate 38. They are fixed by positioning pins so that they

  can not turn. Although any geometric configuration

  The scroll bar 28 can be used, a change of direction wheel 28 is advantageous because it eliminates losses due to secondary currents. The volute 28 may be secured to the housing 34. However, in a

  advantageous configuration, it is in the form of a

  replaceable report. The transition to hydrodynamic profile

  The volute is made with two concentric annular inserts. These inserts 70 and 72 are fitted into a concentric cavity formed in the casing 34 during assembly of the pump. After assembly, the fluid discharge passage formed by the outside of the two rings co-operates with the discharge channel formed in the main casing 34. The inner ring 72 of the volute contains the spout 26 or the volute tip. The spout 26 is in the form of an additional insert and is placed between the inner ring 72 of the volute and the plate

  internal 66 of the diffuser. In an advantageous configuration

  The scrolls are formed of cast white cast iron and the spout is made of tungsten carbide K-703. This

  divided volute configuration allows access to the inte-

  of the volute and forms free surfaces allowing additional surface treatment, for example a

  possible surfacing with tungsten carbide.

  Since the operating temperature of the pump is 290 ° C and the white cast iron and tungsten carbide have different coefficients of thermal expansion, the carbide wear ring of the wheel is placed with a radial clearance. When the operating temperature is reached, the material has expanded

and centered the carbide ring.

  The shrunken ring material is an alloy steel 4340 and the exposed portion of the ring can be surface tungsten carbide deposition.

by flame spraying.

  Each stage of the centrifugal pump module 10 comprises at least one external inlet 12 and an external outlet 30, at the periphery of the main housing 34. These external inputs 12 and these external outlets 30 allow

  loading and unloading of floors while allowing

  both a live maintenance of the pump 10. In a

  advantageous figuration in which the pump module 10

  two-stage centrifuge, an external conduit 32 of crossed

  can be added so that it can

  in series. In this mode of operation, the discharge outlet of the low-pressure stage is connected to the inlet 12 of the high-pressure stage via the conduit 32. The latter may be formed of any material of high mechanical strength but it is preferably a material adapted to that of the main housing 34. It should be noted that the external outlets 30 advantageously have a shape

  frustoconical and play the role of secondary diffusers.

  The main hydrostatic seal described in the aforementioned French patent application No. 80.02830, provides the seal in the case of coal suspension in an oil of particle size at least equal to 43 p at a temperature of about 290.degree. a difference

  pressures ranging from about 1.75 to 10.10 Pa.

  However, according to the actual criteria to which the pump

  must satisfy, different joints, allowing different

  e 7 pressures of up to 3.5.10 Pa can be used. Similarly, the seal 44 placed between the stages is advantageously of the type described in the United States patent application.

  No. 64,320, filed by Fritz C. Catterfeld on August 6, 1979.

  This particular seal 44 is intended to function in

  severe conditions as indicated above. This-

  during, it should also be noted that any joint joint placed between the floors gives satisfaction according to the criteria

  fundamentals set for the operation of the pump.

  Although the elements and operations described above can be modified so that the pump operates under ambient conditions, the temperature

  in general is determined by the temperatures

  erations of treatment. In the installation concerned, the

  operating temperature is advantageously

  viron 2900C. Temperatures of this order for the pump require the pump to be warmed up before

  getting started. The operation must be carried out for several

  important reasons. First, more importantly,

  the main elements of the pump must not be able to

  not be damaged by thermal shock. Then, the drive shaft of the pump must be concentric to the motor. The pump is mounted on a horizontal central axis, with a three-point mounting system on four supports. A first mounting device, located on the inlet side of the pump, is fixed and the other mounting device on the inlet side of the pump allows elongation by radial expansion. A third mounting device on the outlet side of the pump allows elongation

  axial expansion by thermal expansion while the fourth

  Positive mounting gives full latitude in the horizontal direction

  any zonal. The pump has a dilatation

  from the fixed mounting device; consequently

  quence, the central axis of the pump moves in the plane

  horizontal relative to the engine. The importance of this

  placement due to thermal expansion depends on the setting made when mounting at room temperature; therefore, the pump must be heated to a temperature

  such as the drive axes of the pump and the motor

  are virtually concentric. The third

  temperature requiring heating is imposed by

  differences in thermal expansion of the elements

  dull of the pump, especially when some parts are made of tungsten carbide. For example, a wear ring of tungsten carbide of the wheel, mounted with a diametral clearance of 0.36 mm at ambient temperature, is not

  not centered until the pump reaches 175 to 1050C.

  Similarly, the rotary assembly mounted on the shaft which has a relatively small mass compared

  to the assembly mounted on the housing, expands faster-

  the case; as a result, the shaft support bearings are mounted via a frustoconical joint allowing axial clearance and

  some flexibility, such as Belleville washers.

  These washers constituting springs are more compressed than during their assembly, during the thermal transition, but they nevertheless reach the appropriate adjustment to the operating temperature. The most convenient method for heating is the injection of hot fluid into the pump itself until the operating temperature is reached and allows the admission of the suspension and the start of the pump. It must be wrapped in an insulation sheath preventing

  important gradients of temperature between the

  and the outside of the pump can cause significant thermal stresses in localized areas and can cause cracking of the structure. Stopping the pump for inspection or other reasons is performed after draining the interior and removing the slurry that may harden during cooling. Purge plugs 80 are formed in the lower cavities of the inlet and discharge volutes.

  Figures 7a and 7b are diagrams of

  corresponding to the front edge of the wheel and to its

  posterior border, under the conditions indicated above.

  It is furthermore noted that the centrifugal suspension pump which bears the reference 6 can operate in the manner of an expansion turbine which bears the reference 100 in FIG. 5, when the circulation of the fluid changes direction in the pump 10. , in a second series of advantageous embodiments of the invention, it relates to a two-stage expansion turbine module 100 which can operate under very severe conditions. These conditions include a high temperature and pressure, a high volume flow rate and a medium that can cause intense erosion. FIGS. 6a to 6d, in which like figures denote like elements, represent a two-stage suspension expansion turbine 100 and FIGS. 8a and 8b are velocity diagrams corresponding to this turbine. It should be noted that the two floors of the

  turbine 100, placed face to face, have the same operation.

  Figure 5 is a perspective with torn parts

  an expansion turbine 100 in which a fluid

  is entered in the module 100 by an entry 102 and in a convergent spiral 104 of change of direction. Under the most advantageous operating conditions, the inlet 102 is delimited by an insert element 103 of hard metal while the convergent spiral comprises inserts 105 and 107. The fluid coming from this spiral 104 is conveyed along the guide 106 transition (Figures 6a, 6b and 6d) and enters the radial inlet nozzle 108 without wings so that the fluid is accelerated to the rotor 110 of the turbine. This rotor 110 rotates in the direction imposed by the tangential inlet 102 and the convergent spiral 104. The inlet radial nozzle 108 comprises a plate smooth finish internal coating 102 and a plate 114 external finish coating

  smooth, separated by a distance equal to the width of

  rotor. The plates 112 and 114, like the plates 105 and 107 of the spiral, are formed of very hard white cast iron. In addition, the surfaces of the plates

  112 and 114 are closely adapted to the profile of the spirals.

  As in the case of the pump 10, the surfaces of the regions which undergo a high wear wear a coating

  hard surface, for example boride.

  The fluid, when he lost part of his

  kinetic energy, leaves the radial rotor 110 and is

  by means of current rectifying fins 115 to an outlet spiral 117 (which is part of the main casing of the turbine) and the outlet 119 of the expansion turbine. The fluid stream is (1) is returned via a conduit 120 to the inlet 102 of the second stage in which the expansion operation is identical to that described for the first stage, so that the turbine is mounted in series, (2) be transported to an outdoor location

  allowing parallel assembly of the floors of the tur-

  It should be noted that, although the expansion turbine module 100 is used in a two-stage turbine as previously indicated, the invention is also applicable to the turbine module with one or more stages. The differential pressure of expansion is 1.75.106 Pa per stage. When the two stages are mounted in series, the total difference of relaxation pressiors is 3.5.106 Pa per module. Given the difference between pressors between the rotorsplaces face to face, a seal must be provided by joints between floors. Such a seal 44 placed between the stages is of the type described for the centrifugal pump 10, two hydrostatic seals being pressurized by a purge fluid transmitted at a pressure greater than that which prevails within the

  100 relaxation turbine. Similarly, a suspension

  The high-pressure section is sealed with respect to the atmosphere and with respect to the other sensitive elements of the turbine, for example the bearings, by a hydrostatic seal 46 which is controlled by a compatible purge fluid by means of a a hydraulic interface between two different fluids, allowing

  obtaining a theoretically null velocity of circula-

  fluids forming the interface.

  According to the criteria set for the operation of the expansion turbine, the housing 116 thereof can be formed of any material of high mechanical strength which can be used in practice and can be molded practically with any desired thickness of walls.It should be noted that the housing 116 comprises the body of the turbine. Given the severity of the operating criteria of such a turbine, the housing 116 is advantageously formed of molded ductile steel, for example steel ASTM-216 G.R.WCB, and

  the average wall thickness is about 5 cm.

  The main casing 116 of the turbine is

  pleated by plates 118 forming end caps.

  moth. These plates contain many functional elements

  which are necessary for the support and sealing of the turbine module 100. The functional elements are the same as those shown in Fig. 3a for the pump 10 and include the shaft support ball bearing 40 having the seal 42 which encloses a lubricant, the double mechanical seal 45 and the main hydrostatic seal 46. This main seal 46 and the seal 44 formed between the stages are advantageously of the type described in the aforementioned French patent application No. 80.02830 and in the aforementioned United States Patent Application No. 64 320. It should be noted that functional elements

  must be identical and must have an identical

  tick in the two end plates 118. Each of the elements can be removed from the corresponding plate 118

  without the plate itself being removed from the turbine 100.

  However, in an advantageous embodiment of the invention,

  As a result, the plate 118 can also be removed with the various elements mounted therein, after removal of the bearing housing 48 and the rolling clamp nut 50. The rotating members are stacked from each shaft end 52 toward a shoulder 54 formed in the middle of the main shaft 56 so that the interior of the

  the expansion turbine is accessible from both sides.

  The rotors 110 of the turbine are assembled on

  the main tree 56 so that they are face to face. The opera-

  Partly, because the inlet 102 of the two stages is part of the main housing 116. The two rotors 110, exerting axial thrusts in opposite directions, ensure the balancing of the assembly comprising the rotors with respect to the fixed parts. Although any material of high mechanical strength can be used, the shaft, in an advantageous configuration, is made of alloy steel No. 4,340 and the elements mounted on the shaft by sleeves, including the rotor of the turbine, are formed of alloy A-286, tungsten carbide or alloy steel No. 4 341 or 4 330. Two sleeves placed on the shaft are preferably formed of alloy A-286 which is refractory and resists corrosion. In this way, the differences in thermal expansion of the tree and

  elements placed on the sleeves are compensated and the

  puncture is kept tight between the temperature

  biante and an operating temperature of about

  2900C. It should be noted that the turbine can also be

  read to operate at room temperature. In this case, thermal expansion is not a problem

  and any other suitable material may be chosen.

  Ball bearings 40 are also part

  of the rotating assembly. They are placed at both ends.

  of the shaft 56 and tightened by a nut 50.

  rotary elements, as well as the tree 56 and the

  tors 110, must all be carefully balanced during

  of manufacture so that wear is not excessive.

  During operation, the absolute velocity and the pressure of the suspension stream are reduced in the turbine 100 so that energy is transmitted to the rotors 100. The speed diagrams of the centrifugal pump 10 are shown in FIGS. 7a and 7b while those of the same pump operating in a hydraulic turbine are shown in FIGS. 8a and 8b. The only ones

  differences concern the meaning of speed vectors,

  presenting the reversal of the current in the pump.

  As indicated in FIGS. 7a, 7b, 8a and 8b, the speeds at the inlet of the rotor 110 are the same as at the outlet of the pump wheel, apart from the direction. The speeds at the outlet of the turbine rotor are slightly different from those of the pump impeller inlet,

  the difference being 6 (as shown in

  broken). This result is due to the fact that the pump impeller turns the current less than the rotor of the pump.

  turbine during operation. As a result, the

  the impeller of the impeller of the turbine has a greater rotation or swirl than that which is given by the curving vanes prior to the inlet

of the pump wheel.

  Thus, the greatest rotation provided by the impeller rotor causes fluid flow to enter the straightening guide vanes at a negative angle of incidence of 100, giving a slight mismatch and possibly causing potentially higher erosion. . However, a slight shortening of the anterior edge of the straightening fins (i.e.

  posterior edge of the forward curvature fins)

  do not have an angle of incidence of 0 to the current and thus avoid losses and erosion. When the pressure decreases

  the hydraulic turbine 100, the dissolved gas is progressively

  of the solution and forms a vapor-liquid mixture having a small volume fraction of vapor. In a spinning stream, a low density fluid such as vapor collects in the center or towards the core of the flow that flows freely, that is to say far from the hydraulic surfaces. The rotary current or vortex formed at

  turbine rotor discharge is a location other than

  the steam can be collected and discharged from each turbine stage by a suitable hollow shaft. Another

  appropriate gas manifold is shown on the

  5 on which a collector tube 122 withdraws the gas

  released in the cross connection conduits 120.

  Due to the operating temperature of

  2900C of the expansion turbine and the difference in di-

  thermal exposure presented by the white cast of

  Tungsten carbide, the wear ring of the carbide rotor is placed with a radial clearance. When the turbine reaches operating temperature, the material has expanded so that the carbide ring is centered. The shrunken ring material is No. 4,340 alloy steel and the exposed portion of the ring may be tungsten carbide deposition surfaced.

by flame spraying.

  Each stage of the turbine module 100 has at least one external input 102 and an external output 119 placed

  at the periphery of the main housing 116. These exits

  102 and these external outputs 119 allow the

  In an advantageous configuration in which the two-stage expansion turbine module 100, an external cross-connect duct 120 can be added so that the stages can be added. operate in series. In this operating mode, the outlet 119 of the high-pressure stage is connected to the inlet 102 of the low-pressure stage via this duct 120. This can be formed of any material having a high mechanical strength but it is advantageous that this material is in agreement with that of the main housing 116 of the

relaxation turbine.

  The main hydrostatic seal described in the aforementioned French patent application No. 80.02830 seals a suspension of coal in the oil with

  a particle size of at least 43 p at a temperature of

  about 2900 ° C. and for a pressure difference of between about 1.75 × 10 6 Pa and more than 2.1 × 10 7 Pa.

  about. However, according to the real criteria of

  of the expansion pump, various seals,

  operating up to 3.5.107 Pa can be used.

  Similarly, the seal between the stages is of the type described in the aforementioned U.S. Patent Application No. 64,320. This particular seal is intended to operate under the severe conditions described above. However, it should be noted that any common joint intended to be placed between the stages can be

  used, according to the basic criteria of

turbine operation.

  Although the elements and operations of the expansion turbine, described above, can be modified for use under ambient conditions, the operating temperature is determined by the process temperatures. In the installation considered,

  the operating temperature is advantageously

  viron 290'C. The operating temperatures of tur-

  bine of this order require a temperature of the turbine before it is started. This must be done for several important reasons. The first and most important is the removal of the

  thermal shock which could deteriorate the important elements

  tants of the expansion turbine. Then, the training axis

  the turbine should be turned concentrically. The tur-

  is mounted on a horizontal central axis, with a system

  three-point mounting system arranged on four supports.

  One of the mounting devices on the input side of the tur-

  is fixed while the opposite device on the side of

  trea allows radial thermal expansion. The third

  mounting device, placed on the output side of the tur-

  bine, allows axial thermal expansion while the fourth mounting device allows free movement in any horizontal direction. The turbine extends to

  from the support which is in a fixed position; consequently

  In this case, the central axis of the turbine moves in a horizontal plane. The amplitude of this displacement due to heat depends on the setting adjustment at room temperature; in

  therefore, the turbine must be heated to a temperature of

  such that the drive axes of the turbine and the motor are almost concentric. The third criterion requiring warming is the difference

  thermal expansion of the various elements of the tur-

  especially when it contains parts made of tungsten carbide. For example, a rotor wear ring formed of tungsten carbide, placed with a diametral clearance of 0.36 mm at ambient temperature, is not

  centered as long as the temperature of the pump is not

taken between 175 and 2050C.

  Similarly, the rotational assembly mounted on the shaft has a low mass relative to the assembly attached to the housing and therefore expands more rapidly than the housing; as a result, the shaft support bearings are mounted so that they can move axially,

  with some flexibility, through a

  frustoconical positive flexion, for example

  Belleville washers. These washers are compressed

  more important than during their assembly during the thermal transition; however, they resume the proper setting at the operating temperature. The most convenient method for warming up is perhaps the injection of a hot fluid into the turbine

  proper until the operating temperature

  and the admission of the suspen-

  commissioning and commissioning of the expansion turbine. That-

  it must be wrapped with an insulation sheath preventing

  the appearance of important thermal gradients between

  the interior and exterior of the turbine because such gradients could cause thermal stresses in localized areas and could cause structural cracking. Stopping the turbine for inspection or other reasons requires purging the inside and removing the suspension that could

  harden during cooling. The operation is

  in the manner indicated for the centrifugal pump.

  Thus, the invention relates to a rotary apparatus

  centrifugal pump or expansion turbine function-

  at high temperature and pressure, with a volumetric flow rate

  high density, suitable for the chemical industries, dredging

and material handling.

  It is understood that the invention has been described and shown only as a preferred example and that we can bring any technical equivalence in its constituent elements without departing from its scope.

Claims (48)

  Centrifugal pump (10) with two stages, characterized in that it comprises a pump housing (34), at least one inlet device (12) and an outlet device (30) for each stage of the pump, input and output devices passing through the periphery of the pump housing and having a direction substantially transverse to the axis of the pump,   a device (14) for directing circumferences   basically the fluid flow in each stage, this   device being placed along the inner wall of each   floor of the stacker (34) so that it turns the neck   fluid in the direction of rotation of the wheel and that   reduce the velocity relative to the wheel entry and essen-   substantially at the diameter of the wheel end (18), two end plates (38) removably mounted on the pump housing (34) for facilitating the direct maintenance of the centrifugal pump. (10), a shaft (56) placed axially between the plates   (38) and supported by them via   of several bearings and several seals, two wheels (20) placed face to face at the rate of one wheel per stage, the wheels being mounted coaxially on the shaft (56) of the pump so that the fluid pressure increases, a diffuser (66) for receiving the fluid of each wheel (20), a volute (28) for receiving the current of each of the diffusers (66), a spout (26) placed between each diffuser (66) and the volute 28) so that it directs the fluid of the diffusers (66) into the volutes (28), and a sealing device (44) on the shaft (56) of the pump, this sealing device being placed coaxially along the shaft (56) between each wheel (20) and the corresponding end plate (38) to prevent fluid leakage and support the shaft. 2. Pump according to claim 1, characterized in that it comprises several input devices (12)   and a plurality of output devices (30) for each stage.   Pump according to claim 2, characterized in that   it has a first input device (12) and a first   first output device (30) for the first stage of the   pump (10) and a second input device (12) and a second   output device (30) for the second stage.   4. Pump according to claim 3, characterized in that it comprises an external connection (32) crossover for connecting the first output device (30) to the second input device (12) so that the stages   of the pump (10) are connected in series.   Pump according to Claim 3, characterized in that the inlet (12) and outlet (30) devices are mounted in parallel.   6. Pump according to claim 1, characterized in   the output device (30) is formed by a different frustoconical fuser.   7. Pump according to claim 1, characterized in   what the device intended to direct circumferential-   the fluid stream (14) has fins (16) curvature.   8. Pump according to claim 7, characterized in that the vanes (16) pre-bending are   integral with the inner wall of the housing (34) of the pump.   9. Pump according to claim 7, characterized in   the vanes (16) of preliminary curving are dis-   Removably placed along the inner wall of the housing (34).   Pump according to claim 9, characterized in that   what the vanes (16) of preliminary curvature are molded white cast iron.   11. Pump according to claim 1, characterized in that it further comprises inlet scrolls (14) for reducing the relative speed of entry level   the diameter of the entrance end of the wheel.   Pump according to one of claims 7 and 11,   characterized in that the pre-bending fins (16) and the volutes (14) have their coated surface a curing agent.   Pump according to Claim 12, characterized   in that the coating is formed of a boride.   Pump according to Claim 1, characterized   in that a seal (44) is placed between the coaxial stages   along the shaft (56) of the pump between the wheels (20). 15. Pump according to claim 14, characterized in that the seal (44) formed between the stages comprises two opposite seals, arranged coaxially along the   the shaft (56) of the pump between the wheels (20).   16. Pump according to claim 1, characterized in that the diffuser (66) is a radial diffuser without fins.   17. Pump according to what the diffuser (66) 18. Pump according to what the diffuser (66) nested, aligned to 19. Pump according to what the diffuser (66) pump.   20. Pump according to what the diffuser (66) 21. Pump according to what the diffuser (66) hardening.   22. A pump according to claim 23, characterized in that is replaceable.   claim 17, characterized by having two parallel walls the displacement of the wheel.   Claim 17, characterized in that it is embedded in the housing (34) Claim 17, characterized in that   is formed of cast white cast iron.   Claim 17, characterized in that it is surface-coated with an agent claim 21, characterized in that the curing agent is a boride surface treatment. Pump according to claim 1, characterized in that the volute (28) is of the type ensuring a change of management.   24. Pump according to claim 1, characterized in that what the volute is replaceable.   25. Pump according to claim 24, characterized in   the volute (28) is nested in the pump (10).   26. Pump according to claim 24, characterized in   that the volute (28) is formed of cast white cast iron.   27. Pump according to claim 26, characterized in that the volute (28) has its surface coated with a curing agent. 28. Pump according to claim 27, characterized in   the curing agent is a surfacing of a boride.   29. Pump according to claim 1, characterized in the spout is replaceable.   Pump according to claim 29, characterized in that what the beak is reported.   31. Pump according to claim 29, characterized in that   the spout (26) is formed from a carbon-based alloy tungsten bure.   32. Pump according to claim 1, characterized in that the device ensuring the seal on the pump shaft comprises a self-centering seal (46) controlled   by a fluid and operating at high pressure.   33. A two-stage expansion turbine, characterized in that it comprises: a turbine casing (116), two end plates (118) removably mounted on the casing (116) of the turbine and intended to facilitate direct interview,   at least one input device (102) and one   positive output (119) for each stage, the input (102) and output (119) devices passing through the periphery   housing (116) of the turbine and being placed in direct   substantially transverse to the axis of the turbine (100), a convergent spiral (104) of change of direction for each stage, arranged so that it receives the current of each input device (102) of the turbine, a finless inlet radial nozzle (108) for each stage, radially positioned to receive current from each convergent spiral (104), and the received current to be accelerated, a replaceable spiral transition guide (106) for each stage, placed between each spiral (104) and chaquetuyère (108) so that the fluid of each spiral (104) is directed in the corresponding nozzle (108), a turbine shaft (56), placed axially between   end plates (118) which support it through   a plurality of bearings and a plurality of gaskets, two turbine rotors (110) facing each other at the rate of one rotor (110) for each stage, the rotors being coaxially disposed on the shaft (56), a set of vanes (115) of adjustment for   each floor, placed along the inner wall of the bowl.   turbine (116) to receive fluid from each rotor (110), and shaft-mounted seal (46)   (52) of the turbine and placed coaxially along this   between the rotor (110) and the corresponding plate of   mite (118) so that the fluid can not escape and that it assures the support of the tree.   34. Turbine according to claim 33, characterized in that it comprises several input devices (102)   and a plurality of output devices (119).   35. Turbine according to claim 34, characterized in that it is a two-stage expansion turbine (100) having a first pair of input devices.   (102) and output (119) for the first stage and a se-   conde pair of input devices (102) and output (119) for the second floor.   36. Turbine according to claim 35, characterized in that it further comprises an external connection (120) crossed for connecting the first device-output -2468763   (119) to the second input device (102) so that the   stages of the turbine are mounted in series.   37. Turbine according to claim 36, characterized in that the external connection (120) further comprises a gas manifold (122). 38. Turbine according to claim 35, characterized in that it can be connected by external connections so that it comprises an assembly of the group which comprises two independent inputs and two independent outputs,   two independent inputs and one common output, one   a common entrance and two independent exits, a com- mune and a common exit. - -   39. Turbine according to claim 33, characterized in that the input device (102) further comprises   a replaceable insert (103) formed of hard metal.   40. Turbine according to claim 33, characterized   in that the spiral (104) is replaceable.   41. Turbine according to the claim in that the spiral (104) is provided (100).   42. Turbine according to the claim in that the spiral (104) is molded. 43. - Turbine according to claim in that the volute (104) is coated in hardening agent.   44. Turbine according to the claim in that the curing agent is a rure. 45. Turbine according to that the nozzle (108) 46. Turbine according to that the nozzle (108) nested rows.   47. Turbine according to that the nozzle (108) 48. Turbine according to, characterized in the turbine, characterized white cast iron 42, characterized surface of one - 43, characterized surfacing of claim 33, characterized is replaceable. claim 45, characterized is delimited by two walls claim 45, characterized   is reported in the turbine (100). claim 45, characterized   in that the nozzle (108) is formed of cast white cast iron.   49. Turbine according to claim 48, characterized in that the nozzle (108) is coated on the surface with an agent hardening.   50. Turbine according to claim 49, characterized in that the curing agent is a treatment according to boride surface.   51. Turbine according to claim 33, characterized in that the volute transition guide (106) is reported.   52. Turbine according to claim 33, characterized in that the volute transition guide (106) is   formed of an alloy of tungsten carbide.   53. Turbine according to claim 33, characterized in that it comprises a seal (44) placed between the stages, arranged coaxially along the shaft (56) between the rotors (110) of the turbine.   54. Turbine according to claim 53, characterized in that the seal (44) placed between the stagescomporte two opposed seals, mounted coaxially on the shaft (56)   between the rotors (110) of the turbine.   55. Turbine according to claim 33, characterized in that fins (115) of recovery are integral   the inner wall of the housing (116) of the turbine.   56. Turbine according to claim 33, characterized in that the fins (115) for rectification are arranged removably along the inner wall of the casing. (116) of the turbine.   57. Turbine according to claim 56, characterized in that the fins (115) of straightening are formed cast white cast iron.   Turbine according to Claim 33, characterized   in that it further comprises a spiral (117) of   intended to reduce erosion at the outlet (119).   Turbine according to one of claims 33 and 58,   characterized in that the straightening fins (115) and the outlet spiral (117) are surface coated with a curing agent.   Turbine according to claim 59, characterized   in that the coating is formed of a boride.