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(11) | EP 0 667 486 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Instantaneous accumulating steam generator |
| (57) In a steam generator there are provided: a funnelled conveyor (11) from inside the
chamber (13), with winding shape to soften confluence of said steam when drawn from
said chamber; and outside, downstream of the conveyor (11) and centrally therewith,
a "plenum chamber" (17), operating as flywheel, from which chamber said steam is gently
drawn and sent outside. The probe (23) inside the boiler (1) is equipped with a protection
chamber (25) for protecting the stem (27) thereof from condensate deposit formation
thereon and false level signals caused by depression; the resistances (29) are provided
at a very long distance between end portion (31) and flange (5). |
[0002] It is known that, in prior art instantaneous steam generators, unbalance conditions occur between steam consumption and steam generation inside the steaming chamber.
[0003] This is due to the chamber internal volume and to the internal depression range that brings about an increase in water level, thus decreasing the steam chamber.
[0004] Moreover, the flange surface allows a humidity entrainment due to the depression occurring during the steam flow from steam chamber to solenoid valve.
[0005] Resistances usually have poor wear resistance due both to the high temperature and to the reduced water volume created by the depression range.
[0006] Object of the present invention is to overcome said drawbacks by providing a steam generator of the above-mentioned type in which the amount of produced steam and the amount of required steam are balanced, without creating a strong condensate entrainment and without excessively stressing the resistances.
[0007] A further object of the steam generator according to the invention is to avoid false level signals on the internal probe, due to condensate deposit formation on the probe after the entrainment occurring on the flange.
[0008] These and further objects together with other features and advantages, are attained by the instantaneous steam generator of the invention, wherein:
- a central, funnelled steam conveyor is provided from the inside to the outside of the steam chamber, designed in such a way as to gently draw steam from inside said steam chamber, said conveyor being of a winding shape adapted to soften the confluence of said steam when drawn from said steam chamber;
- a "plenum chamber", that is a steam vessel operating as flywheel is provided outside the generator boiler and located downstream and centrally with respect to the above conveyor, from which vessel the steam is drawn and sent outside without sudden variations of the balance between water and steam inside the boiler;
- the probe inside the boiler is equipped with a protection chamber for protecting the probe stem from the condensate deposit caused by the depression occurring on the flange lower surface as well as from false water level signals, caused by the displacement of said water volume by depression;
- the resistances are provided at a very long distance between end portion thereof and flange, in order to avoid those strong, sudden changes of temperature to which usual resistances are subject.
[0009] Further features and advantages of the invention will appear from the following detailed description of an embodiment thereof, given as a nonlimiting example, with reference to the accompanying drawings, in which:
Fig. 1 is a side elevation view of a longitudinal section of the steam generator of the invention;
Fig. 2 is a top plan view of the boiler of said generator;
Fig. 3 is a side elevation view of a longitudinal section of the outlet conveyor applied to an outlet opening of said boiler;
Fig. 4 is a side elevation view of a longitudinal section of the inlet conveyor or mouth applied to the inlet opening of the steam vessel or "plenum chamber" applied to the boiler.
[0010] As clearly shown in the Figures, the steam generator of the invention comprises substantially a small boiler 1 to which a cover 5 is sealingly fixed in 3; this cover 5 is usually plane and is secured in place by a plurality of through bolts 7 extending through said cover 5 and a suitable circular projection 9 provided on the outside cylindrical wall of the boiler 1.
[0011] Centrally to the cover 5, a central, funnelled steam conveyor 11 is provided, from the inside to the outside of the steam chamber 13, designed in such a way as to gently draw steam from inside said steam chamber 13.
[0012] For that purpose, said conveyor 11 is of a winding shape, with neck 15 in the Venturi-like tube (see Fig. 3), said neck being adapted so as to facilitate and speed up the steam flow from the boiler 1 to a vessel 17 located downstream.
[0013] Said vessel 17 is provided outside the generator boiler 1, and it is centrally located with respect to the conveyor 11, and operates as steam "plenum chamber".
[0014] The steam enters said vessel 17 through an inlet conveyor 19, also equipped with neck 21 in the Venturi-like tube, said inlet conveyor 19 being aligned with the outlet conveyor 11 from the boiler 1 and completing the function of softening for the steam flow from said boiler 1 to said vessel 17.
[0015] The steam will be sent to users through an outlet hole 21, provided in the Figure on top of the vessel 17, and also equipped with funnelled mouth.
[0016] The probe 23 inside the boiler 1 is equipped with a protection chamber 25 for protecting the stem 27 of said probe 23 from condensate deposit formation caused by the depression occurring on the flange lower surface as well as from false water level signals, caused by the displacement of said water volume by depression.
- a central, funnelled steam conveyor (11) is provided from the inside to the outside of the steam chamber (13), designed in such a way as to gently draw steam from inside said steam chamber (13), said conveyor (11) being of a winding shape adapted to soften the confluence of said steam when drawn from said steam chamber;
- a "plenum chamber" (17), that is a steam vessel operating as flywheel, is provided outside the generator boiler (1) and located downstream and centrally with respect to the above conveyor (11), from which vessel (17) the steam is drawn and sent outside without sudden variations of the balance between water and steam inside the boiler (1);
- the probe (23) inside the boiler (1) is equipped with a protection chamber (25) for protecting said probe stem (27), from the condensate deposit caused by the depression occurring on the lower surface of the flange (5) as well as from false water level signals caused by the displacement of said water volume by depression;
- the resistances (29) are provided at a very long distance between end portion (31) thereof and flange (5), in order to avoid those strong, sudden changes of temperature to which usual resistances are subject.