DE1640064A1 - Explosion-proof control protection - Google Patents

Description

- 'Explosion-proof control contactor ) ie »rfiudLUZ concerns the explosion protection electrical .. switch in an explosive atmosphere. fii e applies to ns- special ones in an explosive atmosphere elei # - iri-cfie, ichalter, who fell into a lrert`äs - # - r ° e ,. EL - the switch box is located on the left side. which iifi fol, -.- elideii as u überdruck_ICarmner bezeictuzet: ° rird. @@ f >>'. be the [@; rfinduizg is: but not the vnatz JLer @@: @> I.osioilr- #: 1 octric lorrcii-tun-en before eventual , rcai. @ leäi, but to prevent the through! en @ = chal @ t- äur olelitriscien -schal ter res @ el = aw. @: i @ro ler @ -ele = E @ -i = il i c11 auft retend cif 't @ Lrtzhen die ix!: I # rebezde, as exulosive ajz @ e @ oi @: bring an atmosphere to the X -: - lo io - 1. The @, yrlo: protection against ions by the. rerdruckkan.mer will by the fact that - 1 . ;: ier electric i ages in a dense, or almost dense Y_asten housed i2t, as vrelcher at @. 'eachtu _ @@ - e, -: i sser y @ ereliz der _zor # i_ale @ chaltir-aste l serve -, - ka: -_ n. . Aul this: eise "" -rird -the inner atmosphere repent the äut, ', ere from: 7eticht. 2. an __xriosiv -., Rerder the troz; _z; re -. ~: @ i- asten tar i - iclert te-se At-os;: # hre -vr @ 3. -, o -_ ^ _ e = en ind-ff'ere_-th, d .. r_. _ic_ht; renrhare gas _e-oilden. =: a; s _ ac ter-.er ° is with a supply the- indi -'fere ^ te T; -er- bu: rde ^,: which under -.- one. : iUneren than de = aruct 7Phalten -.rird. y-abei is to be observed ==, daä.r: ie _4t_-iosph: re im caste --- # r-zere n bei: e tti = ': z_n J e.- ele_rtri- sch en -chalters the eror ^ er_che r; liferenz 'give: lt. To achieve that- 'st it -ot@-.e .d- @, 3a. = _e u: __ Te @ ende A @ r ^ osrhwra chT -i_1 das 12cere cl ez Kas @e nS -e == = a = -, despite the `_fact, '_a = nasty si @ _- a durcn url @ rer: _e-dbare: @ a_-torer ._; e @ .-;, _ = z tFt .ir ^, be-it-, there: D the caste-. from finishedv_nrstech @ -sche _ @, ri, nrle @ _i or @@ .. if rr'aiJ. from or _er! - l. _ is leaking. : The supplied? NertFas is therefore u = .ter a :: higher 'ruclals the outside :) of the 1 <asten located- liche, as explosive an-e-.ZO: rme_e atmosphere. For the execution of suppressed: ae. standing-_ 'cha1t- Boxes are in official public documents - precise Safety regulations have been established. In particular, it is required that: the control box is pressurized before the electric @ 'c: zalter -ti-n ter @. @ zna @ .r- -c sets "@ ir-3 before the>'? nterdruclcsetzen des: _chal t #: a3te <zs: furch da. ^ lnert - as the ex: @ osi. # A -: as is razed out; the; der - berdr ucit im fast: i: __ erc: 1 s ^ 1 a: 1ze aä_ rec_.rr- hold @vird until the .-- ä ---- u- :,: = o: -. e e.:_ electrical Scarf - '"- er zenoxrie,; vir,"@c?:; = Er _-if: sei: ze : 'meanwhile! - :: ery a @ si @ Le _ __e.:_._. .) a: erä'f. _? @ an;: ce @ - @e te-.zars cl._a _: a n_ t @ r ä i ...: e @@@ .___ _ .G - ste_ = __ ;; ec = e blow e ur eleh try @ -c: e @ c @ iat.-_ @ lasE @ _t CD # i 2e__ ur d @ cha- ._- eläase @.,.:: @@ `r-liche 'er: ^ - @ct_: z_,: gen # e e_ T @ ° _ cer systems under observation, for example for electrical control devices that can be operated manually with a lever or handle, as well as for the control of electric motors, whereby these various types of application are possible in explosive atmospheres, as they are in plants in the chemical industry or in refineries or in the Oil production (be it on land rigs or on drilling rigs) or on board ultankers or tankers for non-flammable liquefied gases through contact with the atmosphere.

The object of the invention is to create a control contactor, which meets the specified requirements, and 'minimum requirements with regard to prescribed implementation conditions with regard to the pressurization that before the inert gas is swept through and the tightness nder-relative tightness of the chaltkaster_s, which may generate YLLriken electrical. Contains switch and assumed by one to be explosive. the atmosphere is surrounded.

The tax treasury contains at least one: detector., Which one first and a second chamber, the first chamber consisting of two of the pressurized inert gas in the same way: through-flow compartments, which through an aperture from each other are separated, and the second. Chamber one acting on an electrical contact and tensioned by a return spring Has piston ,. and with the compartments. the first chamber is connected so that the pressure prevailing between these compartments on both sides of the diaphragm = I difference acts against the force of the return spring tü: f the calving.

:; Further details and advantages of the invention result from the following description of the figures, in which; -fiz .. 1 the schematic diagram of an inventive Tax 'protect; -Fie. 2 and 3 two preferred embodiments of the invention and the schematic diagram of a modified embodiment of the invention shows.

On # W`ipuren 1 ', 3 and 4 two areas Z @ are more explosive Area and Z2 as ni'clit explosive area, both through the schematic wall, P separated, shown. -In area Z2 there is an electrical system S L, which is not designed to be explosion-proof in any 'tit'. These For example, the system is supplied with electricity from a network E and controls the flow of electricity via a housing under internal overpressure "- which is explosive in deru Area Z1 1iezt. The electrical Anlaz-ea_2 @ z in particular an electrical switch CE and a time switch connected to this> TI, whose Zaech will be explained later will be out. The electrical switch CE is with the housing E through e = connected in multi-core cable GM.

The housing IS ', in which the different, schematically represented by the Rectangle i: - The electrical relay shown is contained by the it Feeding the supply line Cireit Inerteas.

The housing E does not have to be completely tight. =: s -.äst, leakages that are covered by a leakage line, so that the control contactor can. Regulations, it is sufficient that the amount of inert gas supplied by the ersorgimzs1Ei t .. @ n: g C1 can cover all gas losses to such an extent that a v'zck can be maintained in the housing -E, which corresponds to the various -in dE-tert is the same.

The actual detector is _n zigzag. 't marked with the -B; ezuzs- -wichen 1. It is connected to the housing 3 by the intermediate line 0 2, which opens into a first compartment 2 of a first chamber 3. The chamber is divided into two compartments by a diaphragm 4 provided with a calibrated blade 5. The second compartment 6 is connected to a discharge tube C3 for the inert gas J. The detector 1 also consists of a second chamber 7 in which a piston 8 is displaceable, the movement of which is limited by the shoulder 9. The piston -8 is provided with a piston rod 10 , which can slide into a 1 ~: ohru_n --- 11, which is located in the front wall of the 7th. A return spring 12 presses the piston. t against the paragraph ä, as long as the detector is not under pressure.

The piston acts via the piston rod 10 on an interrupter 13, which is in an Iz-aTunerrauT above chamber 7 so a3.xgebrawn: G is,. that the The door closes when the piston is closed, the return spring beve - t.

The breaker 1 3 is connected to the time switch DT by a two-wire Cable c: B, which penetrates the partition wall P --- t, connected.

The compartments 2 and 6 of the chamber 3 are connected by the lines 1, 4 and 15 to the two compartments formed by the piston 8 of the chamber 7 in such a way that the pressure difference between the compartments 2 and 6 counteracts the restoring force of the Spring 12 acts.

The detector has, among other things, two each in cbn compartments 2 and 6 * filters arranged below and above the entry points of the newspapers 14 and 15 16 and 17 on.

In fig. 2, the detector 1a is housed in a single block , the lines 14 and 15 being replaced by the bores 14a and 15a. In the remaining details this detector agrees with the one in I; 'ig. 1 match. -In zig. 3 is the detector 1b itself in the below interior Housing Eb under excess pressure: The detector 1 b is with the ir-Fig. 2- except for the following detail identical; Piston 8 is _with the --internal wall of the second Chamber 7 connected by a reverberant 1 8 which creates a mini mum of friction between the piston and the chamber can be achieved target. ? ei this:.: Detector is of course not an intermediate Line C2 necessary, it is enough if in the first Chamber an i_f tion 1? is located. --ie _nsrteas7irkulaticn inside the housing A = b is achieved by inner collecting lines and baffles, not shown, in order to completely empty the interior during purging with the inert gas before the application of voltage. from the initial existing: to achieve an explosive atmosphere.

The control contactor described is based on the assumption that the purging is through. the inert gas is constantly maintained, be it by a 'constant Nifenge, which has ensured the displacement of the original atmosphere, be it, -in an embodiment not pursued further here, in an after: this initial one. Flushing to the amount required according to the safety regulations Both according to one and the other view, the amount flowing out of the housing is slightly less than the amount entering due to the leakage losses and is directed towards the detector, whose chamber is throttled by the diaphragm 4 -3 it flows through ..:,) ae control contactor normally works in such a way that the pressure difference between compartments 2 and 6 exceeds a jert which is so great that the double-acting. Y, olben: # - e men die '-: action of the return spring 12 is brought into a position 7 in which the breaker, 13. closed ig-k. The closing of the breaker 13 causes a signal, which indicates that the `Lorrich-tiiL1-- is working normally. This signal is passed on from the explosive zone 1 through the cable Cl3 to the time switch DI. This causes a delay before the electrical switch 2, which the voltage setting of the electrical n relay = _ located in the housing which is under internal overpressure is carried out, is actuated.

empty is to be noted, that the side between the sides of the diaphragm 4 prevailing pressure values .z is greater than that prescribed for the interior of the housing nd.es-t-overpressure, that- @ o opens and closes the sub-blezer 1 3 or it through- being gi-rlc. = TallerL sich @. rö @ r, sselbst -open = n 1ä ß t. of the various losses in the inert - askreislaif @ <u` @ der Ln, rehK.se against the atmospheric pressure the prevailing pressure be even greater than the -iiruc kaball a = _ the 1e z? e 4: The safety conditionsLu2E of the L overpressure: rd: thereby increased.

- The leader is according to a strict Mhstsikalischeu law Durehi1Lißme uze uze so depending on the pressure drop cei @ = through-penetration of the diaphragm measured, -.aF during the duration t of the delay3.ri- the 'e_`: -xe of the the explosive atmosphere originally located in it can freeze-free: thereby -will the safety regulation of the arr% i-lsr-zl-zl-zl: fulfilled.

0 One becomes - cheerful -; z`estbtelle: that the time delay t not only 'rir'_t in one direction, that is, with regard to the flow rate: ides #herbrechers 1: 3, but that the relay T. immediately out of the way of SDannuniu nasty j ,; ird, Gveizi, for example, the amount flowing through the diaphragm should be too small. _ ! ::; 3i e: irzun, s; #travel of the tax contactor to the 'i-are: @ 1 to ? n; --- 'to be explained,: -; ground irr fol.en.eh several > Fall e throughf-esriräzhe, iy ds.H at : ": CTB.Ie = @ de .. ^. : - expensivecc li @ üz it he ei pull K._e. --iic _? _ - .. "Ehr -i Cer > .or: .a; pe: - = indesüwen-e beau-Ts-hL ^ -t, se vErrinrern @ = c_ überil = cr = -sz> urch - 1u: - '. me, -1 £ 7en: a: 1d nrüce. The through = _lu. through the 'leilde 4 becomes. e °.: -: @ the _, @ ° `@ '# ^ _._-. Ere: _-:? =, C'? itself -12 4 E3 ^ är # @ __. Q? z. _ "--ach un z, eY er 1 _: S3 C ' . _ _ _ü - .. -... the e_ . at "` ° - @. _ l -ii Z. - 2. If the supply line C1 is completely or partially broken, the gas flow decreases or sinks to * below the flow losses, whereby the voltage from the electrical relay is recognized immediately as under Kiffer 1.

3. If the flow losses exceed due to poor or incomplete seals a certain value, be it due to deterioration of the fittings, the passages For the Babel, etc., there is a decrease in the flow and a subsequent one except. Set tension as a result.

4. If the diaphragm 4 becomes blocked completely or partially, the supply line C1 continues to maintain the internal overpressure, but does not flush the interior space before it is switched on. In this 1-a11 the piston 8 pushes the interrupter 1? close anyway and function as if everything were normal. For this reason there are filters 16 and 17 on both sides of the end 4 and the adjacent pressure lines 14 and 1'5 or 14a and 15a, the meshes of which are very small compared to the opening of the diaphragm 4. The risk of blockage of the diaphragm 4 is thereby transferred to one of the filters 16 or 17, and in both cases the flow through the pipe is reduced, with the result that the relay 14 is de-energized, 5. The discharge line C3 becomes blocked; then. everything runs as in the case of the blockage of the filter: 17, the overpressure is maintained, but not the flow ... this also results in a de-energization ..

6. If the discharge line C3 is leaking, the control contactor needs it not to be overridden from the point of view of safety regulations, the piston 8 does not move. In any case, the effect remains that the fine-mesh metallic filter 16 and 1'7 the interior of the housing from the surrounding Shield the atmosphere and, with certain reservations, a kind of explosion protection grille can form. - -Of course you have to look at the case too. grasp that several, Housing under internal overpressure with various electrical relays, each of which are switched by a control contactor according to the invention, via inert gas lines connected in parallel are acted upon: and that the inert gas from them via lines that are quietly connected in parallel.

EIat in this case one of the housings a @ Zeck, which pressure and flow to the other, in the. Housings - housed electrical relays - sink. leaves, if the loss of the back is large enough, all will be put out of control, -.

On the other hand, one of the housings is no longer for some reason pressurized, it remains nothing = nevertheless connected to the discharge line, their overpressure in relation to the atmosphere - which, by the way, is - because of different downstream losses are not negligible. It would therefore be a Backflow of the gas into the housing, the air pressure of which is faulty, take place, and an overpressure built up in this housing due to the considerable backflow -.rerden.

Now the drainage line could start from one. Flushing Her nech contain gas, which would be explosive. The control contactor according to the invention However, would discover this error immediately, since the piston and the orifice are not on and around a static overpressure special = n. a d2 uamic pressure difference: work together, namely, -rjas is even more important, only in a certain direction of flow.

In Figo 4 another embodiment of the: rizü_ng is shown, The same in this figure with the corresponding parts of the s-J..guren 1 to 3 Wear parts the same reference numbers with the addition of the capital letter A.

The control contactor consists of two detectors, an input detector 1A-e and an output detector 1A-s, which are identical. These two detectors are connected in series via the housing with internal pressure relief and the leakage line FA, which is attached next to it, 4h. that the inert gas stream coming from the supply line C 1A first flows through the chamber 3A-e with the aperture 4A-e, then fills the housing EA and again .in the chamber 3A-s of the Aus, a, .n sdetektors 1A-s and flows out through the Abführleitun.-C3A.

The breakers 13 A-e and 13 & -s, each from the bilateral Acting pistons 81 - e and v A-s. are also; "; her das zweiadrize Cable CBA, which actuates the time switch 71'A -3, - wired in series. With this dearly, the security is increased by this: 3ert, because both the one as well as the other detector must close a break contact so that the electrical relay: -A is assigned @ ar @ u. #. This arrangement reduces the 'tahrschel nlichkcit an undiscovered material failure of the Tax ;: contactor.

The case has been discussed above that with a simple Detector completely or partially clogs the aperture. I'm a simple detector there no protection against this phenomenon; one can 'Probli: ch-Iceit of constipation reduce the aperture with the help of filters 16 and: 17.

In contrast, in the embodiment according to FIG. 4, the filters 16A-e, 17A-e or 16 A-s17 A = s are retained as a useful prevention; An interruption or restriction of the flow through the Ausrangsttektor 1 As causes a reduction of the flow rate through the input detector 1 Ae, where-1 is put out of voltage by the relay 1: A. On the other hand, there was a reduction in the flow rate in the inlet detector, which was not noticed by the inlet detector itself. (for example by clogging its aperture) , 1 from - the exit gate. Discovered.-Also in this embodiment, the filters of each detector are redeemable. They reduce the likelihood of a gradual loss of the two lobes and goblets according to two physical laws would decrease so that both pressure drops would not change in spite of the flow reduction. According to these laws, the amount of leakage losses, the inlet and outlet pressures, which would necessarily change with the flow rate, would also be included ..

The case that both pressure drops despite the change in the flow rate Remaining pale size can, however, only occur in theory.

Even in this theoretical case, the overpressure would still be assured, since the current, which no longer exists, would not be discovered.

Another example is to demonstrate the advantage of the embodiment according to FIG. 4 clarify.

An embodiment of the invention has been discussed above, which had a single supply line and only one discharge line, with multiple housings were subjected to internal overpressure from a single pressure center. Here should the Lec._1_4Terluste one of the housing - this is determined by the regulations especially stressed - don't get excessively large. '.: an must therefore pay attention to it before they get too rough. -Un instantaneous or permanent irregularities To switch off the flow, one is a little bigger in a Ge @ tuse - = flow as den zag Ichliei3uiz, des ün terbr. echer: io _ @: ta << tes necessary maintain.

So you get to the -eis-iel with a common arrangement of n relays with a -: # - withdrawal of the excess flow from n-1 housings by the nth housing through the use of simple statement detectors an important I: ec-Trerlust this Housing verdec t - "errl-en: Dazezen can be reached with a zach 11.:r. 4 exits Control contactor that there must be a smaller static pressure in the housing # E.A, ; m the _.- thrust requirement caused by the Zeck losses -aer aperture 4A-e of the leaked housing to cover, reducing the flow rate through the == aperture rA-s of the off, on - sdetektor immediately so @rerrin? er t: rird that the piston 8 A-s interrupts the electrical: 'jtromkre-.s of the relay located in the housing n.

Claims (1)

P atentans p_rü ch e 1. 'Explosion-proof control contactor with an inner. overpressure, from. an inert gas flushed through and weighing closed circuit before the closing of the circuit, continuously flowed through housing, g - characterized by a detector ('), which consists of a first chamber (3) and a second chamber (7), the first chamber having two compartments ( 2, 6), which are separated from one another by a diaphragm (5) and are flowed through by the inert gas flowing through the housing (E), which is under internal overpressure, and the second chamber (7) on a bilateral piston (8 ), which of the. between the two compartments (2, 6) to both =. @siten the orifice (5) _ the prevailing pressure difference is controlled and acts against the = restoring force of an ßüctstell spring (12) - on an interrupter (13). -2. . . Control contactor according to claim 1, characterized in that: gekenzzeic hn et that the. Leiden Kai ^ meri (3, 7 ) of the detector (1) are connected to each other by two Ilerbin, 3u_nzsleitunzen (149 15). 3. 'control contactor according to claims 1, thereby zeke --ir -ze -; chances that the first ka: r-er (3) rait_ dem Housing (E) through a stream of inert gas Intermediate line ( @ 2) is connected. Äteuerschütz -zach claim 2, characterized by - draws that the piston (j one with it has rigidly connected piston rod (10) which i »a bore (11) -directs and on the, interrupter (13) presses ..- -teuerschütz -Zach spoke 1, thereby #, re know - shows that the breaker (13) rides you switch (DT) is connected,:; = elcher in one non-explosive area (L2) and the electrical cal relay (__) at @@ pannaux: @ - sets. Control contactor zach. Painting 1, thereby identifying - eichnet that he # the first hamrc: er (3). z «., mature in Fascii = e filter (1, 17) aut "reis, @, @ relahe to be used . ei = d .er -le = de () above v__d below the @. @ r-ündunes en der -; ° er-indanzslei t,., # - en (14, 15) arge CrvneT are. . . @tnaersc = _a-cr Claim 1, thereby, geke _ @ @_ - z. eich = _ et, da .. der =? ei @@ vhalter (L) eire 1. @ citerz @ er - @ - evokes, @@ e :: @ 7_cyens so zrol r @; @ ie @ .ye zum.urehs; üler dies @ -eh.uses (Z) _otviendi @ e y @ t ... '@ control contactor according to claim 1, characterized in that the piston (8) is connected to the inner wall of the second chamber (7) by a bellows (18) . Control contactor after. Claim 1 characterized by the fact that the first (3) and second (7) channels are in one .. Block (1 a) are uz @ .d by a two-way binding openings (14a, 15a) " 10. 3 control contactor according to Ans-Oruch 9, characterized in that the block (1a) is located in the housing (2b). 11. Control contactor according to claim 1, characterized in that that there are two detectors (1A = e, 1A - s) on = Neist, which are switched one after the other in the I - lert- @ as: 3 front, r ~, - with the interrupter (13 A -e, 13 A - s) in the same. '': are also connected in series. 12. Control contactor according to claim 11, characterized in that one of the detectors (1-A - e of the housing (`iA) is located while another !) etektor (4.A - s) 'is located at its exit.