JPS6237613A - Combustion chamber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION SUMMARY OF THE INVENTION A combustor suitable for processing low grade fuel gas mixtures is disclosed. This combustor includes a combustion chamber, a heat exchanger consisting of a long tube 71-lix for supplying low-grade fuel gas to the combustion chamber, and a burner disposed in the combustion chamber.

The burner is suitable for mixing the fuel gas with the low grade fuel gas exiting from the long tube outlet. The heat exchanger is in heat exchange relationship with the fuel gas exiting the combustion chamber outlet.

The passage of fuel gas from the combustion chamber to the outer tube surface of the heat exchanger is covered to allow preheating of the low grade fuel gas mixture before the fuel gas enters the combustion chamber.

[Industrial Application Field] The present invention relates to a combustor, particularly a combustor for burning low-grade combustible gas.

BACKGROUND OF THE INVENTION Energy conservation and pollution prevention measures require combustion techniques that burn low-grade fuels and fuel/air mixtures that generally should not be flammable under standard operating conditions. The presence is emphasized.

The low grade fuel/air stream can recover heat from the exhaust gas and transfer this heat to the incoming fuel/air stream for combustion.

PROBLEM SOLVED BY THE INVENTION The purpose of the invention is to incinerate low grade fuel/air streams, especially in paper, film and fabric coating equipment, tape manufacturing equipment, paint stores, etc., which are generally vented to the atmosphere. The present invention provides a recovery combustor suitable for exhaust streams containing solvents from, for example, The hot fuel gas from the recovery combustor can be used to heat the solvent drying oven or for space heating or for other purposes.

[Means for solving the problem] To this end, according to the invention, a heat exchanger consisting of a combustion chamber and a matrix of long tubes for supplying a low-grade combustible gas to this combustion chamber; Equipped with a burner placed in the
The burner mixes fuel gas with low-grade combustible gas exiting from at least some of the outlets of the long tube, and the heat exchanger is in heat exchange relationship with the fuel gas exiting from the combustion chamber outlet. A combustor with features is provided.

Passage of the fuel gas from the combustion chamber to the long outer surface of the heat exchanger allows for preheating of the low grade fuel gas mixture before entering the combustion chamber.

Preferably, the low grade combustible gas is a fuel/oxygen containing gas mixture. The term "gas" is also intended to encompass vapors. Burners are generally intended to consume fuel/oxygen-containing gas mixtures of low grade or having a composition below the lower limit of flammability at room temperature and atmospheric pressure.

Preferably, the burner includes a housing having a perforated outlet plate, connecting at least one hole in the grate to a fuel line, the outlet of the fuel outlet protruding beyond the plane of the plate; Outlet holes are provided at the periphery to supply fuel gas to at least some of the holes.

The burner is preferably attached to the outlet face of the heat exchanger, for example by bolting, and at least some outlets of the heat exchanger are capable of transferring a gas mixture into the housing of the burner, which is then combusted. .

The low-grade combustible gas can be a low-grade fuel gas stream and can also be a solvent-laden air stream. The fuel gas supplied by the burner fuel line can be, for example, a hydrocarbon gas such as natural gas, methane or propane. Other suitable fuel gases can also be produced by evaporation of volatile liquids.

Further, the present invention provides the following steps: (a) introducing a low-grade combustible gas into the inlet of the combustor; (b) introducing fuel into the burner and mixing the fuel gas with a low-grade combustible gas mixture; The present invention also provides a method for processing low-grade combustible gas, which is characterized by (c) igniting a mixture of combustible gas and low-grade combustible gas.

[Example] Hereinafter, the present invention will be described by way of example with reference to the accompanying drawings.

The combustor comprises a heat exchanger section 1 and a combustion chamber section 2 adjacent to the heat exchanger section.

The heat exchanger consists of a rectangular matrix of long tubes 3, each communicating with an internal inlet manifold 4. The tubes are supported by a fixed tubesheet at the inlet end and by a floating tubesheet at the outlet end.

The heat exchanger is surrounded by a housing 5 whose top and bottom surfaces are spaced from the heat exchanger and form an outflow passage 6 for the exhaust gases.

An internal baffle 7 is provided between the heat exchanger and the heat exchanger to displace the exhaust gases in a suitable cross flow against the outer surface of the tubes 3.

The combustion 'Mt section is connected to the heat exchanger section at the front of the floating tube sheet 8 and can be separated for inspection etc. The burner 9 is mounted on the floating tubesheet 8 and has an associated igniter 10. A dividing plate 11 (which can be attached to the floating tube sheet 8) is used to ensure that the gas does not bypass the combustion chamber space before exiting to the outer side of the heat exchanger 1.

The end wall is provided with a refractory cement lining 12 to prevent the burner flame from directly impinging on the combustion chamber wall.

The burner is shown in detail in FIGS. 2 and 3. The burner comprises a stainless steel plate cube 20 and has open opposing sides. The cube is bolted at one of its open faces to the floating tubesheet 21 to collect the effluent flow from the cube 22 section. A burner plate 23 with a regular array of holes 24 is attached to the other open surface. The fuel gas supply pipe 25 is the burner cube 2
0 and rotated 90 degrees to pass through the central hole of the burner plate 23. The end of the supply pipe is sealed to allow the combustion gases to pass through four outlet holes 26 evenly spaced around the periphery of the pipe 25. Exit hole 2
6 is located adjacent to the burner plate 23 to direct the fuel gas to the outer surface of the burner plate (i.e. perpendicular to the axis of the hole in the burner plate).

A high-energy spark igniter 10 is placed close to the burner. This igniter can be retracted after igniting the burner. Furthermore, a flame detector 13 is arranged within the combustion chamber 2. The interior of the combustion chamber can be observed through a viewing glass (not shown). The heat exchanger section 1 and the combustion chamber section 2 are covered with a suitable thermal insulation material 14, such as a thick ceramic fiber blanket surrounded by an aluminum coating. Exhaust gas exits the combustor via outlet 15.

In use, control and startup of the combustor is provided by a burner management controller (not shown).

First of all, air is supplied to the inlet 4 and fuel is supplied to the burner 9, which is then ignited by the igniter 10. Various safety devices form part of the operational controls, eg shutting off the fuel if the flame is not ignited.

After the burner has raised the temperature of the combustion chamber to the desired value, the air supply is switched to a solvent-containing air stream (low grade combustible gas) which is fed to the inlet 4. The burner 9 can then be operated with a reduced fuel supply or completely deenergized, the action of the burner being controlled by a control device based on, for example, the gas outlet temperature of the combustion chamber. When the fuel is completely shut off, the air stream containing the solvent still moves from the inlet to the combustion chamber and the solvent is burned by recovering heat from the exhaust gas.

In another embodiment of the invention, fuel gas exits the combustion chamber through an annular outlet formed between the cylindrical baffle and the combustion chamber housing. This arrangement tends to reduce the temperature difference between each long tube and to prevent deformation of the heat exchanger outlet face.

[Effects of the Invention] According to the present invention, a solvent drying oven, suitable for incineration of low-grade fuel/air streams, such as exhaust streams containing solvents, etc.
A recovery combustor suitable for use for purposes such as heating is obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of the combustor showing the combustion chamber and burner, FIG. 2 is a longitudinal sectional view of the burner, and FIG. 3 is an end view of the burner. 1... Heat exchanger 2... Combustion chamber 3...
Long pipe 4...Inlet manifold 5...
・Housing 6...Outflow passage 7...Baffle 8...Tube sheet 9...Burner 10...Ignition device 11...Divided plate 13...Flame detector 14...Insulating material 15 ...Outlet 20...Plate cube 21...Tube sheet 22...Tube 23...Burner plate 24...Hole 25...Pipe 26...Outlet hole

Claims (10)

[Claims] (1) A heat exchanger consisting of a combustion chamber, a matrix of long tubes that supplies low-grade combustible gas to the combustion chamber, and a burner disposed within the combustion chamber, and the burner is configured to supply fuel gas and the long tubes. combustible gases exiting from at least some of the outlets of the combustion chamber, the heat exchanger being in heat exchange relationship with the fuel gas exiting from the exits of the combustion chamber. 2. The combustor of claim 1, wherein the burner includes a housing having a perforated outlet plate, and at least one hole in the plate connects to a fuel line. (3) The combustor according to claim 2, wherein the outlet of the fuel line projects beyond the plane of the outlet plate and is provided with outlet holes around the outlet to diffuse the fuel gas over at least some of the holes. . (4) The combustor according to any one of claims 1 to 3, comprising an igniter and/or a flame detector within the housing. (5) The combustor according to any one of claims 1 to 4, wherein the housing is lined with a refractory material. (6) The combustor according to any one of claims 1 to 5, wherein the fuel gas outlet from the combustion chamber is arranged in an annular manner. (7) (a) introducing a low-grade combustible gas into the inlet of the combustor according to any one of claims 1 to 6;
(b) introducing a fuel gas into the burner and mixing the fuel gas with a low-grade combustible gas; and (c) igniting the mixture of the fuel gas and the low-grade combustible gas. Processing method for grade combustible gas. (8) The method according to claim 7, wherein the low-grade combustible gas is a low-grade fuel/air mixture. (9) The method according to claim 8, wherein the low-grade combustible gas is an air stream containing a solvent. (10) The method according to any one of claims 7 to 9, wherein the fuel gas is a hydrocarbon gas.