DE1071729B - Standing steam-heated heat exchanger with helically tightly wound heating pipes - Google Patents

Description

With steam-heated heat exchangers. for heat consumption systems, especially in the case of discontinuous Operation, i.e. with strong load changes and especially when the vapor pressure is above the water pressure comes to rest or when the water of the heating system without additional pump power is circulated, the possibility of steam formation on the heated side of the heat exchanger, which is caused by local overheating and is known to be extremely unpleasant and disadvantageous Noises or steam and water hammer.

As a result of the steam and water hammer caused by the steam formation, among other things above all a closed steam-condensate circuit, i.e. the accumulation of condensate in the heating system almost never be realized. An economical use of heat in the heat exchanger was consequently and also due to the previously unfavorable construction of the heating pipe system not possible.

The invention relates to an upright steam-heated heat exchanger of the type in which which in a known manner the heating pipe system consists of helically tightly wound heating pipes and in which the liquid to be heated is fed in countercurrent to the steam. To such According to the invention, further improving heat exchangers with regard to the disadvantages mentioned above the heating pipes are designed in such a way that the heat-exchanging surface of the heating pipe system in the direction from the steam outlet to the condensate outlet, at least in the upper part of the heating system increases.

According to a further feature of the invention, the straight ends of the helical heating tubes are attached on the one hand to a lower tube sheet and, on the other hand, passed through an upper tube sheet running obliquely upward in the direction of the outlet connection of the heated liquid. These heating tubes also protrude into the steam space above the tube sheet. The arrangement can be devised such that the turns of the individual heating tubes at ^- its upper end gradually decrease in the direction of the outlet nozzle of the heated liquid. Advantageously, the helically wound heating pipes can also be arranged at an angle.

Tn the drawing several embodiments of the invention are shown in Figs. 1 to 4.

In the case of the heat exchanger 1 according to FIG. 1, the steam heating system 2 consists of a multiplicity of heating tubes 3, which consist of helical, tightly wound turns 4 in a known manner. The standing steam-heated heat exchanger with helically tightly wound heating pipes

Applicant:

W. Bälz & Sohn K.G., Heilbronn / Ne.ckar

The helical heating pipes 3 can be produced in such a way that straight pipes are wound into a helical shape in devices specially created for this purpose. In contrast, the ends of the heating tubes 3 connected to a lower tube sheet 5 and an upper tube sheet 6 are straight. So you have no turns. Such a steam heating system having helical heating pipes achieves a larger heating surface of the heating system and an increased utilization of the amount of heat supplied to the heat exchanger, especially compared to the heat exchangers with straight pipes.

The heating pipe system of the heat exchanger according to Fig. 1 forms a heating section, which in different Altitudes also has different temperatures. It is evident that for a flawless one Operation of the heat exchanger also corresponding to different altitudes. Temperatures or corresponding Heating values are assigned, d. h .. one must strive to have a small heating surface there Achieve, where the heat is transferred very quickly with steam and to form a large heating surface there, where a small amount of heat is available. The heating section must therefore, in particular To avoid steam hammer, maintain a very specific temperature gradient. Depending on the individual

Φ5 If necessary, this temperature gradient must therefore be selected.

The choice of the temperature gradient can be achieved by grading the heating surface. This gradation is achieved in the embodiment of Fig. 1 in that the helical heating pipes are of different lengths, namely their lengths increase from right to left. Of course you can the staging of the heating pipe system can also be carried out in a different way than shown in Fig. 1.

909 690/392

Claims (6)

Such a design and influencing the heating section of the heat exchanger accordingly enforce the desired heating values in the sense that if there is a sudden need for heat until the heating surface is completely flooded, brief overheating in the vicinity of the hot water outlet, especially in the case of large heat exchangers, cannot occur , whereby the dreaded steam hammer can be avoided. The helically wound heating pipes of the heat exchanger according to Fig. 1 are also set at an angle. The advantage of the inclined position of the heating pipes can be seen in particular in the better turbulence of the water to be heated. While in vertical heating pipes, for example, the water heated by the lower heating pipe windings is not led away from this immediately, but rather slides along them more or less from bottom to top, which has an unfavorable effect on the heat transfer and the flow rate, the inclined heating pipes lead away heated water from the heating pipe windings after it has been heated, as this tends to flow vertically from bottom to top. The consequence of this is that, compared to the arrangement with vertical heating pipes, the heat transfer is more intensive and the turbulence is increased. Due to the inclination of the heating pipes, an even greater length or a larger surface area of the heating pipe system is achieved. This arrangement of the heating tubes accordingly brings about a further improvement in heat exchangers with a heating system that decreases in accordance with the temperature gradient in the heating surface. From Fig. 1 it can also be seen that the straight ends 7 of the heating tubes 3 are passed through the upper tube sheet 6 and protrude into the upper vapor space 8, the tube sheet 6 being arranged at an angle. If, with a horizontal arrangement of the tube sheet 6, the condensate suddenly comes into contact with the tube sheet 6, which has a temperature corresponding to the steam temperature, it can easily evaporate, causing steam hammer or noises to occur. With the inclined arrangement of the tube sheet 6 and especially when the heating tube ends 7 are led out of the tube sheet 6, more favorable heat dissipation is achieved in the upper part of the heating tube system, which largely prevents the condensate from boiling and thus the formation of steam. According to FIGS. 1 to 3, heat conducting means made of metal are also provided between the upper straight pipe parts. Such heat conducting means can be formed from pipe pieces 9 according to FIG. 1 or from two sheet metal strips 10 forming a wedge shape according to FIG. 2 or from strips 11 according to FIG. 3. Such heat conductors have already been proposed per se for heat exchangers. The purpose of these means is to achieve increased heat dissipation and thus an effect that prevents the formation of steam or steam and water hammer. According to Fig. 4, the heat exchanger is conically narrowed in the upper part of the tank in order to achieve a maximum water velocity at the outlet of the heat exchanger with a significantly reduced heating surface. Claims. 1. Vertical steam-heated heat exchanger with helically tightly wound heating pipes which the liquid to be heated is fed in countercurrent to the steam, characterized in that that the heating tubes are designed such that the heat exchanging surface of the Heating pipe system in the direction from the steam inlet to the condensate outlet at least in upper part of the heating system increases. 2. Heat exchanger according to claim 1, characterized in that the straight ends of the helical heating pipes attached on the one hand to a lower tube sheet and on the other hand through an upper in the direction of the outlet connection of the heated liquid at an angle The tube sheet running out at the top is passed through and into the steam space above this tube sheet protrude. 3. Heat exchanger according to claim 2, characterized in that the turns of the individual Heating pipes at their upper end gradually in the direction of the outlet connection of the heated Lose liquid. 4. Heat exchanger according to one of the preceding claims, characterized in that the helically wound heating pipes are arranged at an incline. 5. Heat exchanger according to one of the preceding claims, characterized in that on upper obliquely arranged tube sheet on the side of the heated liquid between the straight Parts of the heating pipes, heat conducting means made of metal, such as pipes, metal sheets and the like. Are arranged. 6. Heat exchanger according to one of the preceding claims, characterized in that the Container of the heat exchanger is conically narrowed at its upper part. Considered publications:
German Patent Nos. 212 014, 107 924;
British Patent No. 724 249. 1 sheet of drawings