US2985438A

US2985438A - Outflow control device for high heat release combustion apparatus

Info

Publication number: US2985438A
Application number: US763661A
Authority: US
Inventors: Millard E Prowler
Original assignee: TODD SHIPYARDS CORP
Current assignee: TODD SHIPYARDS CORP
Priority date: 1958-09-26
Filing date: 1958-09-26
Publication date: 1961-05-23
Anticipated expiration: 1978-05-23

Description

May 23, 1961 M. E. PROWLER 2,985,438 OUTFLOW CONTROL DE E FOR HIGH HEAT RELEASE COMBUS N APPARATUS Filed Sept. 26, 1958 5 Sheets-Sheet 1 Millord E.Prow

ATTORNEYS M. E. PROWLER OUTFLOW CONTROL DEVICE FOR HIGH HEAT RELEASE ("OMBUSTION APPARATUS May 23, 1961 5 Sheets-Sheet 2 Filed Sept. 26, 1958 INVENTOR. Millard E. Prowler.-

ATTORNEYS.

May 23, 1961 PROWLER 2,985,438

OUTFLOW CONTROL DEVICE FOR HIGH HEAT RELEASE COMBUSTION APPARATUS Filed Sept. 26, 1958 3 Sheets-Sheet 3 INVENTOR.

Millard E. Prowler.

ATTORNEYS.

OUTFLOW CONTROL DEVICE FOR HIGH HEAT RELEASE COMBUSTION APPARATUS Millard E. Prowler, East Meadow, N.Y., assignor to Todd Shipyards Corporation, a corporation of New York Filed Sept. 26, 1958, Ser. No. 763,661

3 Claims. (Cl. 263-19) This invention relates to combustion chambers and particularly to means for controlling the outflow from high heat release combustion chambers. In combustion apparatus of the character referred to, a firing chamber is employed in which the fuel is burned at a high rate with a supply of air for supporting the combustion. The combustion chamber is usually surrounded by an outer shell and a large voltune of diluent air is introduced into this shell and discharged therefrom together with the products of combustion from the firing chambers through a discharge duct or orifice which conducts the heated air and gases to the point of use. In many instances the flames from the firing chamber pass out of the chamber through the duct and may cause damage; also direct radiation of heat from the flames may cause injury to apparatus supplied by the duct; also proper mixing of the diluent air and hot gases is frequently not obtained and stratification occurs at the outlet. Even in apparatus in which all of the air is passed through the firing chamber itself, proper mixing may not be obtained and stratification may The principal objects of the invention are directed to overcoming the foregoing and similar defects of apparatus of this diameter and particularly to provide means for controlling the outflow from combustion chambers in such a way as to produce proper mixing between the combustion gases and diluent air introduced either internally or externally of the combustion chamber, to eliminate stratification in the outflow, to control or restrict the flame travel, to cut ofl direct radiation of heat from the burner so as to prevent excessive temperatures downstream of the combustion chamber and to provide means by which the temperature gradient can be regulated or rearranged to suit the requirements of the apparatus or changes therein which may from time to time occur. Specific objects and advantages of the invention will appear from the following detailed description of, certain preferred embodiments chosen to illustrate the principles of the invention.

In the accompanying drawings, Fig. l is a diagrammatic illustration in longitudinal section showing a high heat release combustion chamber with oil burner and louvered hood illustrating one form of the invention;

Fig. 2 is a similar view showing a modification of the combustion chamber;

Fig. 3 is a transverse sectional view on line 3-3 of Fig. 2;

Fig. 4 is a view similar to Figs. 1 and 2 showing another embodiment of the invention;

Fig. 5 is a transverse section on line 5-5 of Fig. 4;

Fig. 6 is a transverse sectional view of a modification of the construction of Figs. 4- and 5 showing a difierent sleeve valve operating means;

Fig. 7 is a view similar to Figs. 1, 2 and 4 showing an embodiment of the invention in another form of combustion chamber, a construction also being shown for simultaneously actuating the louvers as a group; and,

Fig. 8 is a fragmentary transverse sectional view on line 8-8 of Fig. 7.

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Referring to the drawings in detail, Fig. 1 shows a high heat release unit in which the combustion takes place in a firing chamber 10 at one end of which is an oil burner 12 which discharges atomized fuel. Fuel oil is forced through a supply pipe 14, air for combustion being introduced through the ducts l6. Diluent air is introduced through a large duct 18 into the outer shell 20 and passes around the firing chamber which it cools as it passes outward between the walls and mixes in a mixing chamber 21 with the products of combustion discharged from the firing chamber. The heated gases and air then pass through the discharge duct 22 to the point of use which may 'be a gas turbine, test chamber, drying system or other device Where the hot gases are utilized. A baflle sleeve 23 may be placed between the outer shell 20 and the wall of the firing chamber 10. While the oil burner is illustrated as a source of combustion, obviously gas or pulverized coal or other fuel may be utilized. The firing chamber is illustrated as of metal with cooling fins on the outside but it can have a refractory lining or be otherwise suitably constructed.

In accordance with the present invention, a. hood having openings therein is provided over the end of the firing chamber. As shown in Fig. l a metal hood 24 of generally conical form is used, closed at its end 26, and having a plurality of slots 28 therein, these being shown as disposed radially of the conical surface and each being provided with a hinged louver door 30 which may be actuated by a rod 32 and hand grip 34.

Any suitable means for opening and closing the louver doors may be provided, each door being separately controlled, or mechanism may be provided for actuating all of the doors or groups of doors simultaneously. The doors are preferably so arranged as to give a swirling action to the outflowing gases so as to cause a thorough mixing of the same with the diluent air flowing through the outer shell or jacket 20.

The outflow of the gases can be controlled by the degree to which the doors are opened and furthermore the distribution of the hot gases in the passage 22 may be regulated by opening all or only part of the doors. In this way the temperature gradient across the discharge passage may be regulated 0r rearranged. Direct flow of the hot gases through the outlet duct can also be controlled so as to prevent excessive downstream temperatures. Also the hood and particularly the closed end thereof shield the duct from excessive radiant heat liberated by the combustion at the fuel firing zone, thus further preventing excessive temperatures in the outlet duct.

In the construction shown in Fig. 2, a louvered hood is provided similar to that shown in Fig. l. In this instance air is supplied from a blower 40 which provides air both for the combustion and for diluent purposes. The duct 42 from the blower is divided so as to deliver the air in two streams, one passing through valve means 44 to the fuel burner throat ring 46 while the balance of the air passes through the valve 48 to the space inside of the shell or jacket 20. This air passes to the mixing chamber 2i where it is mixed with the hot gases from the firing chamber which escapes through the openings 28 in the hood 24 as in the construction previously described. These openings are controlled by louver doors 30 and rods 32.

In the construction shown in Figs. 4 and 5, combustion air is supplied by a blower 40 which however is connected by a duct 42a to outer part of a jacket or outer shell 20 and passes through the same to the burner throat ring 46. The entering air cools the combustion chamber and at the same time is heated before passing through the burner throat ring. A separate supply of diluent air is provided which enters through the duct 60 into a mixing chamber 62 surrounding the hood 24a at the end of the firing chamber. In this instance the hot gases escape through tubular discharge nozzles having tapered slots 72 therein which are wider at their outer ends. These are controlled by valve sleeves 74 having openings 76 therein which are wider at their inner ends than at their outer ends (Fig. 5). These sleeves may be rotated on their tubular nozzles'by the hand wheels 78 so as to regulate the outflow. Any other suitable constructions of louvers or nozzles may be employed.

Fig. 6 shows a construction by which a series of sleeve valves similar to those shown in Figs. 4 and 5 may be provided with a single operating device. The hand wheels 78 are replaced by cranks 80 which have crank pins 82 working between pins 84 carried by an operating ring 86 mounted to slide in bearings 88. The ring may be rotated ,in any suitable manner as by being provided with teeth 90 engaged by a worm 92 actuated by a hand crank 94.

, Fig.7 shows a modification of the invention somewhat similar to that shown in Figs. 1 and 2. In this instance, however, all of the air is introduced through a duct 42b and passes between the wall of the firing chamber and the jacket wall or outer shell 20 and passes through the firing chamber where it supports the combustion of the fuel discharged from the fuel burner. In this construction no separate supply of diluent air is provided but all of the combined air and combustion products pass out through the *louvered openings in the hood 24, mixing chamber 21 and outlet passage 22. In this instance the burner is a gas burner supplied by a gas supply pipe 14a.

Means are shown in Figs. 7 and 8 for actuating the louvers in a group by means similar to that shown in Fig. 6. In this construction, cranks 34a are connected to the rods 32a which actuate the louvers. Crank pins 82a work between pins 84a mounted on operating ring 86a which may be rotated in bearings 88a by worm and gear construction 90a, 92a and 94a.

While certain preferred embodiments of the invention have been illustrated and described in detail, it is to be understood that changes may be made therein and the invention embodied in other structures. It is not, therefore, the intention to limit the patent to the specific constructions illustrated but ot cover the invention broadly in whatever form its principles may be utilized.

What is claimed is:

1. A high heat release air heater comprising an inner shell forming a firing chamber and having an outlet end, an outer shell, means for supplying fuel and air superatmospheric pressure for combustion in the firing chamber, means for supplying diluent air to outer shell, a discharge duct connected to the outer shell at a location beyond the outlet end of the firing chamber, and a hood of conical shape enclosing the outlet from the firing chamber, said hood being provided with radial openings in the conical wall thereof, and louvers hinged along longitudinal margins of said openings and adjustable to positions for giving a swirling motion to the gases and mixing the same with diluent air prior to discharge into the discharge duct.

2. A high heat release air heater comprising an inner shell forming a firing chamber, said inner shell having an outlet at its front end and having a rear end in which is mounted a burner throat ring, a fuel burner mounted in said throat ring, means for supplying fuel under pressure to said burner, means for supplying air under superatmospheric pressure to said throat ring for providing air for the supporting of the combustion of the fuel discharged by the burner, the rear wall of said inner chamber being closed except for the passages through said throat ring, a hood enclosing the outlet from the firing chamber, said hood having a generally conical shape and being closed at the outer end and being provided with outlet ports in a conical wall portion of said hood, adpustable valves for controlling discharge of the hot gases from the combustion chamber through said outlets, an outer shell enclosing said inner shell and said hood, said outer shell being provided with a conical reducing section surrounding the conical hood, there being a space between the inner and outer shells, an unobstructed discharge duct of smaller diameter than the diameter of the outer shell attached to the outer end of said conical reducing section and in alignment with the axis of said shells for conveying the heated gases to the point of use, and means for supp-lying the air under pressure to the space between the inner and outer shells for discharge with the hot products of combustion to the discharge duct.

3. A high heat release air heater comprising an inner shell forming a firing chamber, said inner shell having an outlet at its front end and having a rear wall in which is mounted a burner throat ring, a fuel burner mounted in said throat ring, means for supplying fuel under pressure to said burner, means for supplying air under super-atmospheric pressure to said throat ring for providing air for the supporting of the combustion of the fuel discharged by the burner, the rear wall of said inner chamber being closed except for the passages through said throat ring, a

hood' enclosing the outlet from the firing chamber, said hood having a generally conical shape and being closed at the outer end and being provided with outlet ports in a of said shells for conveying the heated gases to the point of use, and means for supplying the air under pressure to the space between the inner and outer shells for discharge with the hot products of combustion to the discharge duct.

References Cited in the file of this patent UNITED STATES PATENTS 194,527 Miller Aug. 28, 1877 1,738,176 Dyer Dec. 3, 1929 2,048,321 Carruthers et al July 21, 1936 2,164,954 Stephens July 4, 1939 2,445,466 Arnhym July 20, 1948 2,518,364 Owen Aug. 8, 1950 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nos 2385 4138 May 23 1961 Millard E. Prowler It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent. should read as corrected below Column 3, line 45, after "air" insert under =5 line 47 after "to insert the column 4 line 10, for "adpustable" read adjustable Signed and sealed this 31st day of October 1961a (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC