FR2587450A1 - ELECTRODE CONFIGURATION FOR A HIGH VOLTAGE ELECTRIC BOILER - Google Patents

Abstract

AN IMPROVED ELECTRIC BOILER STRUCTURE USES A COMBINATION OF HIGH VOLTAGE ELECTRODES 6 JETS WHICH MINIMIZES JET DISINTEGRATION AND RESULTANT DISCHARGE BETWEEN THE BOILER JETS FEEDING WATER COLLECTOR 4 AND HEAT ELECTRODE 4 RECEIVING THE JETS. THE DESCRIBED INVENTION AVOIDS DISCHARGE CAUSED BY INTERSECTION OR ENCOUNTER OF VERTICALLY ARRANGED JETS. THE COLLISION OF JETS PRODUCES THE DISINTEGRATION OR "SPLASHING" OF GENERALLY CYLINDRICAL JETS 6 INTO CRITICAL PARTS ADJACENT TO THE HIGH VOLTAGE ELECTRODE 10 RECEIVING AND CHANNELING THE FLOW (EN 11-17). EQUIPMENT CONSTRUCTED USING THE CONFIGURATION DESCRIBED ENSURES REDUCED BOILER DISCHARGE AT NORMAL VOLTAGES AND EXTENSION OF THE OPERATING INTERVAL AT HIGHER VOLTAGES.

Description

An improved process for controlling the steam flow of a boiler

  electric with water jets electrodes is described in the patent application in the United States of America n 706 719 of the same inventor filed on February 28, 1965o The statement of this request and the accepted amendments make

  part of the references completing the present invention.

  TECHNOLOGICAL BACKGROUND OF THE INVENTION

  The invention relates generally to boilers

  high voltage electrical res and more particularly to high voltage electric boilers using

water jet electrodes.

  High voltage electric boilers of the type using water flow or so-called water jet electrodes have been in use for a long time. The functioning of this type of equipment was described in 1935 in volume XXII, number 3 of the review Brown Boverio In this type of equipment, the flow of water under pressure and directed towards high voltage electrodes is used to conduction heat the water flowing inside a large tank under

  pressure having insulated high voltage electrodes.

  In general, equipment of this type is in operation with three sets of three-phase electrodes under

  high voltage cooperating with a three-way electrical distribution

  widely used phased. Typically, equipment of this type operates at voltages as high as 15,000 volts between phases producing steam at capacities

  up to a power input of 50 megawatts.

  Although many boilers operating at lower voltages are highly reliable and operate satisfactorily, it has been necessary to provide an increasing number of equipment for operation at the upper end of the range, i.e. closer to kV and quite recently market demands have made

  necessary the development of equipment capable of operating

  operate at voltages as high as 24 kV between phases. This trend is due to the increased experience on the use of higher distribution voltages in companies by allowing to benefit from reduced costs sean'aTiquT sesaeqogp sal aasimTuTm inod neap sar uoTsua% alnuq snos apoaoaelgp aiTooarBl. aunp uoT% -sTITinl NOIMNSA ^ NI-G S SMSSd spoiloal, salt oaAB% UBaedooo sa% sap uoTemo U 1% e neil ap. 9% TATonp 5 -uoo BI aeua sanbTTo suoeelai sel ae.asqo uo ellenbul sUBp nua.p szac 'q 88POaOala' uffluel. alneq snos alaqTpnuto aun jasodoid ap ajooua sa uOTuaAUTl ap% a qo ailnu un À sUTmTl9 9%, uo zaldTlnm s% a ap suOTsTlTOO sap q snp sa9 ap UoTe% uTs9p ap sai $ a sal% a uTo% SA-uTo% saneq anod enbToaia% eoa & -a sa8 sap uoTeamo $ el% ueu. zaouoo sanbT4% o sal suoT1uamTp aTlanbel SubP 'neaap its q sapoaloal9 uoTOue% aneq SNOS anbTIoal a9Jqpneqo aun JasodoJd% ap ap his uoTuaAuTil aTeuamlddns% qo At a SE9 salt aeaue uoToDaeuT Amun B strep sanp eqTpnBqo BI sea 5z -Natal, uT% z9e2rao9p sel asTmTuTm Tnb neap sea sepoiloalepp uoTs.n; T $ uoo aun oeau% uueigdooo nsep sea Op uoTUmJo $ aun JasodoJd Op Osa uoTIuOAUil Op 8JTel-uemaddns Da qo un

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  sap aeuUOToOuOJ ap alqd-eo% e e9uuooaeaed nea, p se OZ -se apo =% oelp q uoTsuae aenuq snos enbToealP ajqTpnuqo aun JTlqse, 9, P 1-se UOlu8. & uT eluuuu uu su uo qo qo gel% ueawllQTuassa eaA9 Tnb sapoiloelTp se sap UoT% -T IBJd9l Bl Op uOTBlll2TJuOO ellenou aun, addolaAap BI 1- a seaqapnaqo sep saenaT'aeu sepoaloeal xne suaoe pe sae sep uoToula1 XuTua2 Xu 989seIsTIn SuOTBeIBsuT sel sUBp 'eanb% eanoogp Inale% euI ,, SgaeIq snId aoueszTnd ap xrmeATu xne Iuem - eITlno% ed seanea9% uT ge2aqo8qp ep Ue82STO1o aun% uu% TUn uq% suuozue% sel saaqTpneqo xnme% uenbT-Idd uS * UoTguel. BIl ue-ssTeqa uoTnqTagp ap. ma% ueLaosuBr% un, p aoueszTnd ap saeaed se% ea 9leTTu sasuedp SOI TsuTe% us% TA9 ua sOaTsmTB5 uoTnqTJsp ap s9TnozJo sap o0aa% uemaloaaTp JaeIiTu% uu% uu up% uan u-anoris leuuoT% TppU aqolem ap, naxtoBS uR aT2aauap uoTssTmsuea% Op seu2TI sap OStZ8Sz comes from the discovery of the inventor that the interaction between the Jets or the disintegration of the lower Jets due to the impact of Jets formed by nozzles higher spacing in the distribution manifold was the primary cause of excessive discharges inside the boiler. The disintegration of a uniform jet results in an enlarged flow distribution in the vicinity of contact with the electrode under high voltage. Parts of the now disintegrated jet have a shortened trajectory or path to the edge of the electrode. This shortening of the route significantly lowered the discharge voltage. A uniform jet, coming into contact with the electrode on its most distant surface has a higher dielectric rigidity by minimizing the tendencies

of landfills.

  The discovery of the inventor resulted in the development of a water jet distribution nozzle having an increased length up to a critical value with an equally critical angle of intersection with the associated collector wall. This combination when installed in a slightly modified manifold, establishes a vertical distribution of the Jets which allows

  the recombination of Jets inside the flow part-

  receiving the high voltage electrode. Jets interference is thus minimized and the resulting production of random flow distributions of water mixed around or

  outside the electrode flow conduit is essential

partially eliminated.

  As indicated above, it is this shortened flow path in use on the boilers currently produced which, according to the inventor's discovery, contributes to reducing

  the dynamic internal spacing of the boiler

  re during flow conditions associated with power flows, particularly when operating near

maximum boiler yields.

  The use of the combination structure described and claimed here allows the operation of boilers at

  significantly higher distribution voltages with forma-

  acceptable internal arcing and greatly reduces internal discharges or "trips" in equipment

current under lower voltage.

  Other objects and advantages of the invention will become apparent

  on reading the following detailed description and

  reference to the attached drawing in which: FIG. 1 shows a partial section of a boiler with a traditional water jet electrode, showing in particular the manifold for distributing the water jets and the high voltage electrode under section; Figure 2 is a section through the boiler of Figure

  1 along lines 2-2, showing particularly with arra-

  chely the production of water jets electrodes and the impact on the high voltage receiving electrode for a single high voltage phase; Figure 3 is a section through an electric boiler with a water jet electrode similar to that of Figure 3a but constructed in accordance with the aims and principles of the present invention; Figure 3a is a partial section of a boiler to

  high voltage electrode showing the relationship of the elect

  receiving trode and distribution collector and particularly showing the trajectory of interference jets present in typical equipment currently in use; Figure 4 is a cross section of Figure 3 along lines 4-4 showing in particular the formation of a traditional water jet electrode in which the

  encounter or collision results in an electric shock.

  Although the improved electric boiler according to the invention is described below in connection with the form

  preferred execution, it will be understood that this form of execution

  particular invention should not limit the invention to this realization. On the contrary, this application must cover

  all variants, modifications and equivalent provisions

  nits which can be included in the context of the invention

  defined by the appended claims.

  DETAILED DESCRIPTION OF THE INVENTION

  With particular reference to Figures 1 and 2, the boiler consists of an external tank or casing

  under pressure 2, containing the assembly 4 of the feed manifold

  mentation of water supplying water for the water jet electrodes 6 from the water flowing through a series of nozzles 8. Inside the pressure vessel of the boiler, there is also high voltage electrodes

  Typically, a three-phase voltage is used to generate

  drer the steam with, as described (reference to FIG. 2), three sets of high voltage electrodes 10 which are shown in cooperation with three series of nozzles or water jets 8o The sets 10 comprise a high voltage supply through an insulator 13 establishing a

  electrical connection isolating the pressure to provide the -

  current from an external power source and

  apply it to the inner electrode 10. More particular-

  the passage of current through the insulator 13 energizes the electrode flow channel 11 o The jet electrodes 6 striking the channel initiate heating

  Note, for clarity, Figure 1 does not indicate

  that a single series of nozzles 8 of electrodes in water jets 6 and a single receiving electrode under high voltage 10. Inside the high pressure boiler tank, there is also the outlet part of the pump 12 for the supply water having internal parts of its casing 14 with an inlet 16 and an outlet terminated by a supply water outlet duct 180 Between the pump outlet and the duct 18, there are a set 20 of control valve and actuating element having an actuating element outside the tank 2 for actuating a valve closing element 24. As will be explained below, the setting

  in place of element 24 regulates the supply of feed water

  tation by pump 12 at manifold 4.

  As shown (Figure 1) the supply duct

  supply water establishes a sufficient water level, typically

  only 22, inside the collector 4 by allowing water to flow from the nozzles 8 forming the electrodes in water jets 6 which strike against the receiving electrodes under

high voltage 10.

  Figures 3 and 3a show a partial section of a water jet electrode formation and the construction of a high voltage electrode. Each construction uses, as in the equipment described above, a pressure tank 2 containing a set of high voltage electrodes 10 supplied with high voltage from a terminal 15 by an insulated connector 13 and having a part 11 channeling the Water jet Centrally inside the tank 2, there is a manifold 4 for distributing jets containing a cylindrical part having a plurality of vertically arranged orifices terminating an associated plurality of control nozzles

  8 placed inside the collection set

  tor 4. Each nozzle 8 has an open end in communication

  tion with the water level 22 of the cylindrical collector part and one end terminated by the orifice 5 forming

the water jet.

  In operation, with reference to FIG. 3a, with the collector water level as indicated at 38, the water outlet flow rate from the vertically oriented orifices ends up

  to a vertical column of water jets electrodes

  sant the distance 49 between the cylindrical surface of collection

  tor 37 and part 11 of the flow channel of the electrode assembly. As shown, the trajectories of the water jets electrodes from the high level 39 to the low level 40 produce an interference or an intersection of jets typically taking place in the region represented in 41o. With further reference to FIG. 4, Jets collisions

  produced by the meetings in 41 resulted in a distribution

  tion of the agglomerated water flow with a significant part of the flow now mixed, that is to say a composite jet having elements of Jets 39 and 40. The collision of the Jets alters the initial Jets dimension at point that the descending Jets produced have a component 42 of elements

of Jets 39 and 40.

  Under these conditions, the feed water having a

  electrical potential close to that of the collector for electro

  trodes 4 is now directed to an external part of

  the surface of the flow guide 17. When the assembly of elect

  trodes 10 operates at a potential of the phase voltage, the flow of current through the jet takes place according to the

  passage 43 having a length 49. As this course is nota-

  significantly less than that of the direct path 48, the discharge takes place between the electrode surface and the collector surface in the vicinity indicated in 3. This flow results in a greatly reduced discharge distance and in resulting arcs 43 The uncovering of the inventor of the Jets collision phenomenon led to the formation of the water-jet electrode and to the high-voltage electrode configuration described here and shown in particular in FIG. 3. With reference to FIG. 3 , as described above, the set of electrodes 10 and collector 4 is contained inside a pressure tank 2. The collecting element 4 uses a plurality of nozzles 8, terminated at one end through flow control orifices 5 and in fluid communication with the collector supply water at its opposite end. As shown, the tubular axis of the nozzle 8 is inclined relative to the perpendicular to the manifold surface 37 at the critical angle 46. Additional critical lengths include the width

  nozzle 47 and the distance, shown at 48, between the

  cylindrical face of manifold 37 and the surface of

  tion 11 of the electrode flow under high voltage As indicated, still with reference to FIG. 3, using the

  critical constants determined by the inventor, the traJec-

  upper roof 39 of water jet electrode and lower jet trajectory 40 combine or agglomerate on a

  significantly larger vertical part of the electrical surface

  trode 11. It has also been determined that collisions.or interact-

  Jets such as 41 are much reduced or not

  thus eliminating the arc tendency caused by electrode jets with various speed components 42

(reference to figure 4).

  The inventor also discovered that the increased surface

  the combination of the jets with respect to the flow surface-

  This results in a significantly reduced current density at the surface 11 of the electrode assembly 10o. Local heating and deterioration of the electrode are thus significantly reduced. A continuous problem in the water jet electrode boilers used is the generation

  hydrogen (H2) and oxygen (02) at the electrode surfaces.

  It is well known that the reduced density of the electric current

  trode decreases gas formation through increased recombination. Improved recombination thus results in a

decreased production of H2 and 02.

  The application of the discovery of the inventor under the

  form of the example of execution described-has resulted in an improvement

  notable operation of the high voltage water jet electrode boiler. The inventor observed a 67% increase in operating voltage and a

  50% increase in boiler capacity without increase

  setting the power requirements of the pump

  feed water for water jet electrodes.

  Typical critical constants determined by the

  venteur which produce the above-mentioned improvements in the operation of the boiler are an electrode nozzle length of 15 cm and an angle of 30 between the nozzle axis and a horizontal radius, perpendicular to the cylindrical collector surface. The spacing 48 between the high-voltage electrode and the discharge surface of the collector orifices, taking account of the principles of the invention, is 42 cm and the critical ratio of the radial-spacing 48 to the

  nozzle length 47 is less than 1.88.

  The boiler also includes the termination of the end

  lower part of the electrode assembly 10 under high voltage into a flow portion 26 channeling the flow of return water 24 coming from the electrodes in water jets 6 towards a counter-electrode or grid 30 of return of water operating at the potential of the reservoir or the earth. The channeled water from the Jet electrode passes through the counter electrode, returning to the lower part of the tank o typically a water level

  return 32 is maintained during operation.

  People experienced in the techniques of

  electric boilers will understand that all feed water

  tation of the water jet electrodes in the electrode boilers is maintained at a tightly controlled value of electrical conductivity through the use of products

chemicals added.

  The applicant has further discovered that operating at an electrode voltage of 20 kV makes it possible to reduce the

  conductivity of the supply water from the useful value

  usually between 2000 micromhos and about 1700 micromhos

  while we still get the 50% increase in the return

  of the boiler. People experienced in electric boiler techniques will easily understand

  that this reduction in the conductivity of the feed water

  tion of the water-jet electrodes results in a further reduction in the formation of hydrogen and oxygen on the surface 11 of the set of high-voltage boiler electrodes 10o

  People experienced in the heating technique

  electric ones will understand more easily than a

  a number of auxiliary controls for traditional boilers

  such as the water level indication, the intake of feed water, the safety pressure valve and others are as shown and indicated in Figures 1 and 2o As these elements do not part of the invention, no further explanation of their role

  will not be contained in this presentation.

  '' In operation, the water contained at level 32 inside

  The pressure vessel 2 of the boiler enters the pump inlet 16 and is supplied to the manifold 4 via the pump outlet line 18. The water level 22 essentially determines the quantity of boiler steam supplied to the receiving load because the number of Jets electrodes 6 generated is a direct function of the water level

  22 in the collector 4o The supply water of a conductor

  controlled speed leaving the nozzles 8 and forming the water jet electrodes 6 meets or strikes the central part 11 of the set of high voltage electrodes 10 (reference to

  Figure 2) As the tank 2 and the nozzles 8 function-

  come essentially from the neutral earth voltage while the high voltage electrode operates at the voltage of

  phase of the electric power supply, the water con-

  Jet 6 conductor is heated by the passage of the current which raises its temperature and produces vaporo As indicated above, the quantity of vapor produced and, to some degree, its pressure are determined directly by the number of Jets and by the amount of water coming out of the nozzles which are determined by the water level in the collector. Since only a small amount of the Jets electrode water is heated to a temperature high enough to produce steam, the cumulative flow of water from the nozzles 8 and the Jets 6 takes place vertically towards the low in the flow channel 11 of the high voltage electrode assembly 10, exits the high voltage electrode

  at 26. At this point, the return water from the electrode in Jets -

  of water is essentially at the electrical potential of the elect

  high voltage trode. This is why, as shown, the outlet flow of the electrode passes through a counter-electrode for the return water 30, Like the electrode

  is at neutral earth or tank potential, the

  Lement of the current through the outlet produces additional steam in the return flow 28. All the non-vaporized water returns to the lower part of the tank 2,

  typically by maintaining a level 32. The volume of water contained

  naked at level 32 is functional because it serves as a rest volume tending to reduce turbulence at the entrance to the

pump.

  It is thus seen that, according to the discovery of the invention, an improved boiler with high-voltage water jets electrodes has been proposed which fully satisfies the aims.

  sought exposed above. Although we have described a perfec-

  operation in a water jet electrode configuration

  and high voltage electrodes for special equipment

  link, we will understand that we could envisage many variants and various modifications which will appear to

  experienced people in light of the above discussion.

  The invention must therefore encompass all variants entering

  in the context of the appended claims,

  According to a preferred embodiment of the boiler according to the invention, the angular intersection of the nozzle 8 of the water jet and the external surface of the collector is 60 ′, and the length of the electrode is 190 cm.

Claims (3)

R E V E N D I C A T I 0 N S.   1. In an electrodes type boiler   water jets, the improvement comprising: a reservoir (2) for containing the pressurized steam; an electrode (10) disposed in a generally vertical direction, electrically insulated in said tank (2) having a flow line (11) for receiving the flow from the water jet electrode (6); a cylindrical water collector (4) for water jets having an inner chamber and an outer surface in vertical alignment radially spaced from said flow pipe (11); a plurality of tubular nozzles (8) forming jets   of predetermined length in said manifold (4) and present   both a first end angularly cutting said surface and a second open end; a jet discharge orifice (5) defined by said intersection of a nozzle (8) and the manifold surface; and a critical ratio of radial spacing (48) to the   nozzle length (47) less than 1988.   2. Boiler according to claim 1, in which the angular intersection of said water jet nozzle (8) and the external collector surface is essentially of 60.   3, Boiler according to claim 1, wherein said nozzle length (47) is essentially 15 cm. 4o Boiler according to claim 1, wherein   said radial spacing (48) is essentially 40 cm.   5. Method for decreasing the current density of the contact area of a high voltage electrode in an electric boiler of the water jet type having a plurality of nozzles (8) forming water jets arranged vertically   and a high voltage electrode (10) adjacent vertica-   Lement comprising the operations of: - elongation of the nozzle (8) of water jet; -increasing the projection angle of the water jet; - the positioning of the electrode (10) inside the said water jet trajectory so as to intercept omo 061 op qUmaBTBlaTuasso% s apoiloolap Jnon2uol e; Tpel% e oO ap% sa (9i7) uoToasiauTp otue% TpeI alanbl sup '9 uoTIo S -TpueBaJ el uo0as neesp se enbTioaoel eTpneqDj * 8 (7) .maoaleTIoo Tpnp seneTaadns sesnq easnb sel suTom ni pua.dmoo saeTLnqn% sa. sap% uem.o0% uamelo.% Ja segu2T1e (8) sesnq op% TlJanld e; TpeI ellenbl suep '9 UOTo -TpuBAea ul uoles neap sao enbTloal, 9 altpn3qD Oz - O UOTesTIUUeo ep (Il) spaoq s% 4psap JneTl9uT, 1% 4uaxnoa% as% oleuoo op Bojalns el ep uoToasubuilTubus (9) nuep% a e.Tsodmoo apoloae, aun% uemJo; suoToesJauT sa.TpsaG 's9uTuuelgpaPd   (8) eOUnSTp BTPBU SJOAUo. q% uBpueosap% 0G op aJToB lJ.   eun% uuuTmaeJp (Lt) Janan2uol Tp sl% e (9fil) aBsUe% pel e.qmeqo elpPl suap 9ejaAno 9: mga2lxe epuooes aun e. 9% m -gaJkxa SJaITmJd BJp el -q JnaoTelloO Op aOujang 9 4.UQIUmamJ -TeIn2Ue.uednoo (8) sesnq seTpsel '(i) inaloelloo% TPel sUBp OZ (L) eauTmaJappad.inenSuot eunp senp   sagu2Tlue% uemeToJBa (8) ssnq ap l.TTeanTId eun -   (9i7) eaUTMJGI -ep9ad eluTpe eouesTp Bun q.uameTlnooPiT% uuasPleuro (Il) spioq sap% ae% oBUOo op Boatjns e% çpe [ep og1Iedpa% ue% 9 ue L IOaUOO ap Soat.ns% Tpu%. ue% ue% 9 ejlneTxe9X aoUa.lS e% pul 'ea'naTigxa eoujans aun% e ainaTJaIuT eaqmUiqo eun% u.te% uemoT9eo-jjeA UsodsTp enbTJpuTl.âo teITegug   eaJoI op (1) uoTeueamTlsp nTaap noooslloo un -   uemalnoogl luesTleueo (Il) spioq sap alque s% ep O 1 joBeuoo ap asojns eun uer X (Z) aTOAJSs9J.Tp8l SUUp.UeIEBeO   -T;: I apsodsTp (01) uoTsuS; lXnuq snos apoiBo.alg aun - UOTSOSed   snos JnadeS el ap aTuaeuoo znod (z) JTOAae99I A -   :% ueueadmoo% uemauuOToaead ie 'ineesp seB 5; epoiel.9 ead [4. np enbTjioalI eaqTpnlqo aun suea 9 alemTxem% TOS (0O) uoTsua. eXnaq snos epolzoelap aou; zns e-TPUI JnS% a uni p%; ouUuoo ap aitej anb UObej Sp I sae sap OlsMTUpM uoToaselaUTIp.uTod un ua s%: a sTpseI OS4uLSSz