EP0684432A1 - Three pars boiler - Google Patents

Abstract

The invention relates to a three-pass boiler, comprising a water-carrying housing (1) with a combustion chamber (3) forming the first train (2) with a train remote from the burner and divided into channels (4 ') and extending along the combustion chamber (3) (4) leading exhaust openings (5), to which second train (4) closed to the exhaust gas collecting chamber (7), the third train (6), which is also divided into channels (6 ') and also extends along the combustion chamber (3), extends in parallel. In order to adapt the available flow volume of the trains to the decreasing exhaust gas volume in a simple manner, according to the invention the channels (4 ') forming the second train (4) overall have a larger, flowable volume than that of the third train (6), the larger number the channels (4 ') of the second train (4) below and a smaller number of these channels (4') together with all channels (6 ') of the third train (6) above the horizontal longitudinal center plane (E) of the combustion chamber (3) and the combustion chamber (3) is closed towards the burner side with an annular diaphragm (11).

Description

The invention relates to a three-pass boiler, consisting of a water-carrying housing with a combustion chamber forming the first train with burner distant, leading to the second train divided into channels, extending along the combustion chamber, leading to the second train, the third, also divided into channels and also train extending along the combustion chamber is extended in parallel.

Such three-pass boilers are known, for example, according to CH-A-485 182. The term "parallel extension" with regard to the third train is to be understood to mean that the channels of the third train extend between the channels of the second train, i.e. the heating gases flow through the combustion chamber and the two subsequent trains in countercurrent. The fact that the heating gases cool down on their way to the heating gas outlet, i.e. reduce their volume, has so far and as far as is known only been met by heating gas inlet inserts, the density of which increases towards the outlet side, or that the cross section, for example, of the third outlet, is smaller than that of the second train. As far as is known, the latter was only achieved by having to install several, correspondingly small cross-sectional tubes in the water-bearing housing above the combustion chamber for the third train, moving away from the construction principle according to CH-A-485 182. The upward tendencies of hot combustion gases in the boiler are not taken into account in the boiler according to the aforementioned CH-A-485 182, i.e. the filling level of the heating gas flues in the lower area is worse than in the heating gas flues extending above. In addition, there are a large number of heating gas deflection points on the entire circumference of the combustion chamber, which is probably the cause of a not inconsiderable noise generation in such heating boilers.

The invention has for its object to improve and design a three-pass boiler of the type mentioned in such a way that the entire flow path behind the combustion chamber is adapted in a simple manner to the decreasing heating gas volume and the thus decreasing flow rate of the heating gases, but at the same time the overflow areas from the combustion chamber into the second train and from the second into the third train as open overflow cross-sections, each of which detects all individual trains, that is, discrete separate overflow cross-sections should be avoided.

This object is achieved in a boiler of the generic type according to the invention in that the channels forming the second train overall have a larger, flowable volume than that of the third train, the larger number of channels of the second train below and a smaller number of these Channels are arranged together with all channels of the third train above the horizontal median longitudinal plane of the combustion chamber. In addition, the combustion chamber is closed to the burner side with an annular cover.

In this solution according to the invention, the essential part of the second train is thus arranged in a targeted manner in the lower half around the combustion chamber, while the volume-reduced third train extends with a remaining part of the second train along the upper half of the combustion chamber. Assuming that the entire ring-cylindrical train around the combustion chamber was divided into thirty-two individual trains and the individual trains of the second and third trains were arranged alternately, there would be sixteen individual deflection points from the combustion chamber into the channels of the second train. In contrast, and due to the compact combination of all the individual channels of the second train, there is practically only a correspondingly large deflection point in the embodiment according to the invention. The same situation arises when moving from the second to the third move. Apart from this, the heating gases must first consistently flow through the area of the ring-cylindrical overall train which extends essentially below, i.e. in this lower area a good degree of filling is ensured without other auxiliary measures. In addition to the achievable adaptation to the decreasing flow volume of the heating gases, a considerable reduction in noise formation can be observed and, in addition, such training has proven to be extremely favorable with regard to condensate formation and pollutant emission, which can obviously be explained by the fact that, as mentioned, the hot exhaust gases in the essentially can only pass through the lower area of the boiler. With regard to advantageous further refinements, reference is made to the subclaims to be explained in more detail below.

The three-pass boiler according to the invention is explained in more detail below with the aid of exemplary embodiments.

• Fig. 1 einen Längsschnitt durch den Dreizug-Heizkessel;
• Fig. 2 einen Querschnitt durch den Dreizug-Heizkessel gem. Fig. 1 im Bereich der Züge;
• Fig. 3 A-C Schnitte durch unterschiedliche Ausführungsformen der Zugkanäle und
• Fig. 4 schematisch und im Schnitt eine bauliche Einzelheit.

It shows

• 1 shows a longitudinal section through the three-pass boiler.
• Fig. 2 shows a cross section through the three-pass boiler. 1 in the area of the trains;
• Fig. 3 AC sections through different embodiments of the train channels and
• Fig. 4 schematically and in section a structural detail.

The three-pass boiler consists of a water-bearing housing 1 in a known manner a combustion chamber 3, forming the first train 1, with discharge openings 5 remote from the burner, leading to the second train 4 ', drawn along the combustion chamber 3, 4, to which second train 4 closed to the exhaust gas collecting chamber 7, the third, also divided into channels 6' and also along the combustion chamber 3 extending train 6 is parallel.

Substantially and in accordance with the task, the channels 4 'forming the second train 4 overall have a larger, flowable volume than that of the third train 6, the greater number of channels 4' of the second train 4 below and a smaller number of these channels 4 'are arranged together with all the channels 6' of the third train 6 above the horizontal longitudinal center plane E of the combustion chamber 3. It is also important that the combustion chamber 3 is closed towards the burner side with an annular diaphragm 11 (see FIG. 4).

As shown in FIGS. 3A to C, the channels 4 ', 6' of both the second 4 and the third train 6 have essentially the same cross sections. The embodiment according to FIG. 3 C is a greeting body inserted into a pipe run 10 which extends through the entire housing 1 and which contains the channels 4 ', 6' and which at the same time also forms the wall 9 of the combustion chamber 3. Depending on the length of the combustion chamber 3, this cast body is formed from two or more rings. The volume reduction of the third train 6 compared to the second train 4 is achieved in that, based on the exemplary embodiment according to FIG. 2, the second train 4 is formed by nineteen channels 4 'and the third train 6 by only thirteen channels 6'. The cross hatching shown in FIG. 2 only serves to illustrate the channels that form the second train 4. In relation to the total volume through which the second and third train 4, 6 can flow, about 55 to 65%, preferably 60%, is claimed by the second train.

At the end of the combustion chamber 3, that is to say in front of the combustion chamber base 3 ', there is an overflow slot 5' in the combustion chamber wall 9 in the embodiment according to which detects all the channels 4 'of the second train 4 and forms the discharge opening 5. Fig. 3 B provided.

In the embodiment of the channels 4 ', 6' acc. 3 C, i.e. using a cast body in the form of several individual rings (not particularly shown), the channels 4 'on the last ring are radially open and the channels 6' of the third train 6 are radially closed, but are open axially towards the exhaust gas collection chamber 7.

In the sheet metal structures of the channels 4 ', 6' acc. 3 A, B, the U-profiles 13 ', the sheet metal strips 13 and the combustion chamber wall 9 are correspondingly dimensioned and cut in such a way that corresponding overflow openings result.

The ring diaphragm 11 shown in Fig. 4 ensures that the heating gases generated by the burner 12 can not flow directly into the third train 6, but, as indicated in Fig. 1 with arrows, through the slot 5 ', the second train 4 and between the combustion chamber closure 14 and the ring screen 11 to the third train 6 and from there to the collecting chamber 7 with the exhaust port 8 must take.

The overflow at the end of the combustion chamber 3 thus does not take place in discrete individual flows, and the heating gases leave the second train 4 on a broad front and enter the third train 6 after the flow around the burner 12, which they also have on a broad front as a self-contained exhaust gas stream leave. This avoids cross-pulsations of individual heating gas flows that are otherwise present and presumably responsible for noise generation.

Claims (4)

1. three-pass boiler, consisting of a water-carrying housing (1) with a combustion chamber (3) forming the first train (2) with burner remote, for the second in channels (4 '), along the combustion chamber (3) extending train (4 ) leading exhaust openings (5), to which second train (4) closed to the exhaust gas collection chamber (7), the third train (6), also divided into channels (6 ') and also extending along the combustion chamber (3), extends in parallel,
characterized,
that the channels (4 ') forming the second train (4) overall have a larger, flowable volume than that of the third train (6), the larger number of channels (4') of the second train (4) below and a smaller one The number of these channels (4 ') together with all the channels (6') of the third train (6) are arranged above the horizontal longitudinal center plane (E) of the combustion chamber (3) and the combustion chamber (3) also has an annular screen towards the burner side ( 11) is closed. 2. Three-pass boiler according to claim 1,
characterized,
that the channels (4 ', 6') of both the second (4) and the third train (6) have essentially the same cross sections. 3. three-pass boiler according to claim 1 or 2, characterized in
that at the downstream end of the burning chamber mer (3) an overflow slot (5 ') is arranged which detects all channels (4') of the second train (4) and forms the discharge opening (5). 4. Three-pass boiler according to one of claims 1 to 3,
characterized,
that the channels (4 ') of the second train (4) have a total flow volume of 55 to 65% based on the total flow volume of the second and third train (4, 6).

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