DD261066A3

DD261066A3 - PROCESS FOR PREVENTING COMBUSTION AIR AND GLASS TUBE PRE-WATER

Info

Publication number: DD261066A3
Application number: DD86292110A
Authority: DD
Inventors: Peter Johst; Erhard Herzog; Herbert Heinze
Original assignee: Schwermasch Liebknecht Veb K
Priority date: 1986-07-03
Filing date: 1986-07-03
Publication date: 1988-10-19
Also published as: SU1714295A1

Abstract

Die Erfindung betrifft einen Glasrohrluftvorwaermer zur Waermerueckgewinnung aus Rauchgasen, bei dem die Waende des Rauchgasraumes durch in Kanaelen zirkulierende Heissluft bis auf Temperaturen oberhalb des Taupunktes erwaermt werden. Das Ziel der Erfindung besteht darin, einen Glasrohrluftvorwaermer so zu gestalten, dass die Ausnutzung der Waermeenergie bei der Verbrennungsluftvorwaermung durch Rauchgase bis in den Bereich der theoretisch niedrigsten Temperatur des Heizmediums zu realisieren, um einen maximalen waermetechnischen Wirkungsgrad zu erzielen. Erfindungsgemaess wird die Aufgabe dadurch geloest, dass in den Hohlraeumen zwischen den mittels Spannbolzen verbundenen Trennwaenden und Rohrtragplatten um die Glasrohre koaxial jeweils ein Stahlrohr angeordnet ist, das mit der Trennwand gasdicht metallisch verbunden ist. Die Anwendung der Erfindung erfolgt insbesondere in gasbeheizten Ofenanlagen der chemischen, keramischen und metallurgischen Industrie, Dampferzeugern und Verbrennungsanlagen. Fig. 1The invention relates to a Glasrohrluftvorwaermer for heat recovery from flue gases, in which the walls of the flue gas chamber are heated by circulating in channels hot air to temperatures above the dew point. The object of the invention is to make a Glasrohrluftvorwaermer so that the utilization of heat energy in the combustion air preheating by flue gases to realize in the range of the theoretically lowest temperature of the heating medium in order to achieve maximum thermal efficiency. According to the invention, the object is achieved by coaxially arranging in each case a steel tube in the cavities between the dividing walls and tube support plates connected by means of clamping bolts, which is connected to the dividing wall in a gas-tight metallic manner. The application of the invention is particularly in gas-fired furnace systems of the chemical, ceramic and metallurgical industry, steam generators and incinerators. Fig. 1

Description

In der zugehörigen Zeichnung zeigen:In the accompanying drawing show:

Fig. 1: einen Teilbereich des GlasrohrluftvorwärmersFig. 1: a portion of the glass tube air preheater

Fig. 2: die Anordnung des Glasrohrluftvorwärmers in einem Verfahren zur Luftvorwärmung für eine Gasfeuerung.2 shows the arrangement of the glass tube air preheater in a method for air preheating for a gas firing.

Aus der Fig. 1 ist eine Rohrtragplatte 1 ersichtlich, die jeweils die Enden der Glasrohre 2 aufnimmt. Parallel zu den auf beiden Seiten des Rohrbündels vorhandenen Rohrtragplatten 1 ist jeweils innenliegend eine zugehörige Trennwand 3 angeordnet, wodurch eine räumliche Trennung gegenüber dem rauchgasbeaufschlagten Bereich des Glasrohrbündels 4 erfolgt ist. Die Trennwände 3 besitzen koaxial zu den Glasrohren 2 in entsprechende Löcher eingeschweißte Stahlrohre 5, die an der Rohrtragplatte 1 gegen Dichtungen 6 gepreßt sind.From Fig. 1, a pipe support plate 1 can be seen, which receives the ends of the glass tubes 2, respectively. In parallel to the tube support plates 1 present on both sides of the tube bundle, an associated partition wall 3 is arranged in each case on the inside, whereby a spatial separation from the region of the glass tube bundle 4 exposed to the smoke gas has taken place. The partitions 3 have coaxial with the glass tubes 2 in corresponding holes welded steel tubes 5, which are pressed against the pipe support plate 1 against seals 6.

Die Verschraubung des durch Rohrtragplatte 1 und Trennwand 3 gebildeten Hohlraumes 7 erfolgt mittels Spannbolzen 8. Aus der Fig.2 ist die Einbindung von Luftvorwärmern in einer entsprechenden Gesamtanlage zur Vorwärmung von Verbrennungsluft für eine Gasfeuerung ersichtlich. Die vom Verbrennungsluftventilator 9 angesaugte Frischluft 10 wird in den ersten Glasrohrluftvorwärmer 11 geleitet und durchströmt hierin die Glasrohre 2. Danach wird derzweite Glasrohrluftvorwärmer 12 von der Verbrennungsluft 13 in gleicher Weise durchflossen und gelangt mit erhöhter Temperatur in einen Statilrohrluftvorwärmer 14. Nach erfolgtem Durchlauf steht die so aufgeheizte Verbrennungsluft 13 für den Eintritt in den Brenner 15 des Ofens 16 zur Verfügung. Von der Verbrennungsluft 13 wird eine Teilmenge abgezweigt und mittels eines Warmluftventilators 17 über eine Temperaturregelklappe 18durch die Hohlräume 7 beider Glasrohrluftvorwärmer 11,12 hindurchgeführt. Hierbei werden die in Stahlausführung vorhandenen und die Hohlräume 7 begrenzenden Bauteile, wie Rohrtragplatten 1, Stahlröhre 5 und Trennwände 3 oberhalb des Taupunktes aufgeheizt. Danach wird dieser Teilstrom der Verbrennungsluft 13 dem Hauptstrom vor dem Stahlrohrluftvorwärmer 14 wieder zugeführt. Der Weg des Rauchgases 19 verläuft vom Ofen 16 über den Stahlrohrluftvorwärmer 14 und die beiden Glasrohrluftvorwärmer 11,12 zum Schornstein Mittels eines Drainageanschlusses 21 kann die Abführung des Rauchgaskondensats erfolgen.The screwing of the cavity 7 formed by pipe support plate 1 and partition wall 7 is effected by means of clamping bolt 8. From Fig.2 the integration of Luftvorwärmern in a corresponding overall system for preheating combustion air for a gas firing is visible. The fresh air 10 sucked in by the combustion air fan 9 is directed into the first glass tube air preheater 11 and flows through the glass tubes 2. Thereafter, the second glass tube air preheater 12 flows through the combustion air 13 in the same way and at elevated temperature enters a static tube air preheater 14 heated combustion air 13 for entry into the burner 15 of the furnace 16 is available. From the combustion air 13, a subset is diverted and passed through a hot air fan 17 via a temperature control flap 18 through the cavities 7 of both Glasrohrluftvorwärmer 11,12. Here, the present in steel design and the cavities 7 limiting components, such as pipe support plates 1, steel tube 5 and partitions 3 are heated above the dew point. Thereafter, this partial flow of the combustion air 13 is supplied to the main flow before the Stahlrohrluftvorwärmer 14 again. The path of the flue gas 19 extends from the furnace 16 via the Stahlrohrluftvorwärmer 14 and the two Glasrohrluftvorwärmer 11,12 to the chimney by means of a drainage connection 21, the removal of the flue gas condensate.

Wie aus der erläuterten Schaltung hervorgeht, erreicht das Rauchgas 19 erst im Glasrohrluftvorwärmer 11 seine niedrigsten Temperaturwerte. Diese Temperaturen liegen im Taupunktbereich. Durch die erfindungsgemäße Gestaltung der Hohlräume der Glasrohrluftvorwärmer wird jedoch an den gefährdeten Bauteilen aus Stahl das Auftreten chemischer Reaktionen vermieden. Die vorteilhafte Wärmeübertragung von der die Hohlräume 7 passierenden Verbrennungsluft 13 auf die Trennwände 3 wird im wesentlichen durch die im Wärmestrom befindlichen Stahlrohre 5 realisiert.As can be seen from the circuit explained, the flue gas 19 only reaches its lowest temperature values in the glass tube air preheater 11. These temperatures are in the dew point range. Due to the inventive design of the cavities of Glasrohrluftvorwärmer the occurrence of chemical reactions is avoided at the vulnerable components made of steel. The advantageous heat transfer from the combustion chamber 13 passing through the combustion air 13 on the partitions 3 is realized substantially by the steel tubes 5 located in the heat flow.

Claims

Glasrohrluftvorwärmer for heat recovery from flue gases with cavities between the connected by means of clamping bolts partitions and pipe support plates, characterized in that coaxially around the glass tubes (2) each a steel tube (5) is arranged, which is gas-tight metallically connected to the partition wall (3).

For this

2 pages drawings

Field of application of the invention

The invention relates to a Glasrohrluftvorwärmer for heat recovery from flue gases, wherein the walls of the flue gas chamber are heated by circulating hot air in channels to temperatures above the dew point. The application is particularly in gas-fired furnace systems of the chemical, ceramic and metallurgical industry, steam generators and incinerators.

Characteristic of the known technical solutions

It is customary to heat the combustion air by Luftvorwärmer in tube package design using hot flue gases. However, the process of raising the temperature of combustion air is limited by the dew point range and the corrosive effect of flue gas condensate that occurs. The existing in Glasrohrluftvorwärmern steel pipe support plates and boundary walls are exposed to these negative influences despite the use of high quality materials and stronger dimensions. The drop below the dew point temperature is now counteracted by the fact that the formation of the flue gas condensate exposed walls are heated to a temperature above the dew point. For fastening glass tubes in tube sheets or pipe flanges, it is known that distributed over the tube sheet or in a pipe flange concentric holes of different diameters are formed so that a web is formed. The freely expiring tube end of the glass tube is guided through the web and it is surrounded within the bore of the largest diameter of a sealing element with an associated bolted or welded locking ring. This creates between the glass tube and the surrounding tube sheet or pipe flange a seal after the manner of a stuffing box. (DD-PS 225773)

It is disadvantageous in this embodiment, that while an attachment and sealing of the glass tubes relative to a single wall can be achieved, but this design can no longer be used in the arrangement of a double wall of Glasrohrluftvorwärmers for heating the wall areas by the resulting cavity. In addition, there is no heat transfer between glass tube and wall with this known type of attachment and sealing of the glass tubes.

Object of the invention

The aim of the invention is to realize by the design of a Glasrohrluftvorwärmers the utilization of heat energy in the combustion air preheating by flue gases to the range of the theoretically lowest temperature of the heating medium in order to achieve maximum thermal efficiency.

Explanation of the essence of the invention

The invention has for its object to make the heating channels of a glass tube air preheater so that a maximum utilization of the heat energy of hot flue gases by cooling below the dew point at a required increase in temperature on the walls of the flue gas chamber on the dew point of the flue gases to prevent corrosion phenomena and the achievement a high energy efficiency is realized.

According to the invention, this object is achieved in that'is arranged in the cavities between the partitions connected by means of clamping bolts and tube support plates around the glass tubes coaxially a steel tube, which is connected to the gas-tight metallic partition.

The most significant advantage of the invention is that it is possible by the design of the glass tube penetrations through the cavities and the sheath of the glass tubes to cool the flue gases well below their dew point range. When passing heated fresh air through the cavities, the partitions are so strongly reheated by the heat conduction of Stahlrohrummantelungen that it can not occur dew point corrosion.

embodiment

The invention will be explained below with reference to an exemplary embodiment.