WO1986003719A1

WO1986003719A1 - Self contained engine and cabin preheater

Info

Publication number: WO1986003719A1
Application number: PCT/US1985/002130
Authority: WO
Inventors: Francis E. Robertson; Frank E. Robertson
Original assignee: Robertson Francis E; Robertson Frank E
Priority date: 1984-12-17
Filing date: 1985-10-25
Publication date: 1986-07-03

Abstract

An improved method of heating on aircraft engine and cabin. The engine muffler (2) is used with a shroud (4) to form a combustion chamber and heat-exchanger. A burner (3) provides heat which is transferred to air flowing through the heat-exchanger (2) and into the cabin. A two-way valve (10) controls the air flow. When the valve is closed heated air is diverted into the engine compartment. Thus the engine is heated by conduction from the muffler and by direct contact with the hot air.

Description

SELF CONTAINED ENGINE AND CABIN PREHEATER

This invention relates to engine operator and passenger compartment preheaters and specifically to aircraft engines and cabins.

Heretofore aircraft parked in cold weather have had to hp warmed with large cumbersome heaters usually mounted on carts, although some small ones can be carried by hand. They are all either very cumbersome, time consuming, or inefficient. There are good electrically operated ones except usually electricity is not convenient or even available. Pilots in remote cold areas often place tents over their engines with portable heaters underneath or carry flame type blow torches with stove pipe to direct flame and heat all of which are extremely dangerous.

None known are self contained, built-in and also heat the cabin.

Accordingly several objects of this invention are the ability to land an aircraft in a cold location and with controls that can be located in the cabin, start the heater burning and come back at a time only limited by the amount of fuel to a warm aircraft engine and cabin. Further objects and advantages of this invention will become apparent from a consideration of the drawings and ensuring description thereof.

Fig. 1 is a front view of the invention as in a typical aircraft installation.

Detail 1 shows the preheater butterfly type vent valve in the half open position in said valves bousing 13.

Fig. 2 is a right side view including the cabin heat ducting with as s ociated valves and fuel line 12. Detail 3 is an enlargement of the ram air and the preheaters two way valve with associated control cable 11 and lower opening 5. Figure 3 is an isometric view.

This invention consists of an exhaust system so constructed as to be below or beside or both below and beside an engine. As shown in fig. 1 in a typical aircraft instalation, said engine is between exhaust pipes 5 and above muffler 2, heat shroud 4, and burner 3. The engines exhaust outlet or preheaters inlet 1 is at the lowest point.

A propane gas burner, thermocouple and igniter of conventional design are located in said muffler near said exhaust system. Outlet 1 which during preheater operation becomes said heaters fresh air inlet.

As shown in fig. 2, a heat shroud 4 surrounds said muffler except for the sides. Leading to said mυffler from the front of the instalation is a ram air tube 9. between ram air tube 9 and said heat shroud is a two way valve 8 with opening on bottom 5.

Left of said muffler in fig. 2 is the cabin heat tube 7 with a continual rise in elevation to a two way cabin heat valve 10 located on the cabin firewall entering into the cabin below instrument panel and wind shield defrosters.

Cold air enters exhaust system outlet 1 and muffler 2, mixes with gas and burns at burner 3. Heat and gases generated rise by natural convection out said mufflers silencing and spark arresting cones 7 and up exhaust pipes 5 and out vent valve 6.

Heat generated radiates from said muflers sides 2 and exhaust pipes 5, and rises bv natural convection to the engine located above and between said exhaust system.

Additional heat is transfered to said engine by conduction through said exhaust pipes 5.

Cabin heat is generated by cold air entering the two way valve 8 through its opening 5. Entering the air space between said muffler and said heat shroud being heated by said muffler and rising by natural convection up heat tube 7 and entering the cabin through two wav valve 10 below the instrument panel and wind shield defrosters. If said two wav valve 10 is in the closed position, heat will divert from the cabin to the engine compartment as valve 10 is identical to valve 8 shown in detail 3. The preheater contains therein several component parts which are of conventional design. These components include the said exhaust pipes and muffler. Said eras burner with thermocouple and spark igniter. Butterfly type valve 6 and two way valves 8 and 10 with associated controls. These component parts and their application are well understood by those skilled in the art and therefore the construction and operation of the afore mentioned parts will not be discussed. While the above contains mainly specifics, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one prefered embodiment thereof. Mainly other variations are possible. For example, provided said exhaust system is constructed as shown. That is, with a continual rise in elevation from said exhaust outlet to a point near said engines combustion chambers where said vent is located, so that heat can rise by natural convection. It will then be possible to attach anv portable flame burner to said exhaust outlet and achieve the desired heating. It is also possible to place said exhaust system in most anv location and rely on a blower powered by any means to force operation of this invention. It is also possible to construct the ram air intake 14 below said muffler therebv eliminating two way valve 8, or additional vents can be added to aid circulation.

Accordingly the scope of this invention should be determined not by the embodiment illustrated, but bv the appended claims and their legal equivalents.

It is understood that it may well be that modifications and improvements mav be made in this invention bv those skilled in the art without departing from the spirit and scope thereof.

It is also to be understood that while the invention has been described in terms of certain particular structures, methods, and arrangements. The invention is not to be limited to these structures, methods, or arrangements except insofar as they specifically set forth in the subjoined claims.

Claims

New use claim

A method of υsing an engines own exhaust system as a builtin engine and cabin preheater.

A. Muffler and exhaust pipes acting as heat exchangers.

B. Means of creating a flame within said exhaust system to generate heat.

C. Valves as means of controlling fresh air, heat, and exhaust gases.

D. New use. Using above elements together in any engine to have a safe, self contained, lightweight, compact means of providing heat to said engine, operators compartment, and cabin for cold weather starting.

An improved method of preheating any engine, particularily in air-cooled aircraft engines and cabins without needing electricity or having to carry bulky equipment and batteries along, of having toemploy ecpensive preheating equipment, consisting of the engines own modified exhaust system.