US2663362A - Heater for supplying hot gases - Google Patents

Description

Dec. 22,- 1953 1-, H, RANSQME 2,663,362

' HEATER FOR S UPPLYING HOT GASES Filed July 16, 1951 IN VEN TOR. mfiims'a/m Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE! Tallent H. Ransomc, akland,Calif.

Application July 16, 1951, Serial No. 237,009

2 Claims. (01. 1587) 1 This invention relates to an air heater which is specially designed for use in the drying of cotton and other products or materials.

In the processing of cotton particularly in the ginning operation thereof, it is essential that the moisture content of the cotton is reduced to a predetermined point to insure eflicient ginning. Gas burners using butane or natural gas are employed to heat air by mixing it with products of combustion. The mixture is delivered to a drier by a fan or blower, hence, it is'important that the air and gasratio in the burner remains constant as improper combustion would otherwise result and discoloration of the cotton would take place. The atmosphere in a ginning plant is full of dust and lint and as the gas burners employed are of the Venturi type, material trouble has been encountered, due to the fact, that dust and lint tends to coat the inner surfaces of the Venturi tubes to such an extent as to change the gas and air ratio with poor combustion as a result.

An object of the invention is accordingly to prevent dust and lint from entering the Venturi tube of the burner; another object is to prevent dust and lint from entering the combustion zone of the heater as burning lint might pass through the heater and create a serious fire hazard; a further object is to provide an air heater employing a countercurrent air flow to prevent over heating of metal surfaces surrounding the combustion zone and thereby eliminating the use of fire brick or similar insulating material.

The heater structure is shown by way of illustration in the accompanying drawing which is a plan view of the heater said view being partially broken away and being partially shown in section.

In the drawing A indicates an elongated shell cylindrical in cross section and constructed of steel or like metal. One end of the shell is closed by a burner supporting head indicated at 2 while the opposite end is closed by a flue supporting head 3. Extending through the head 3 is a flue 4, this flue is centrally disposed within the cylindrical shell and extends substantially the length thereof. The flue terminates at a point adjacent the burner supporting head 2, but is spaced therefrom as shown. The end of the flue adjacent the burner supporting head 3 is open as shown at 5 while the opposite end which extends through the flue supporting head is connected with the suction side or inlet of a blower 6.

A main burner 1 of the Venturi type is supported by the burner head 2 and extends therethrough, it is positioned in alignment with the flue 4 and the flame of the burner i accordingly directed into the open end thereof. Formed in the shell adjacent the flue supporting head are a plurality of openings which are covered by a screen 8, hence, when the burner and blower are in operation air will enter through the screened openings and will flow in the direction of arrows at toward and against the burner and its support-- ing head, the air is here deflected and mixes with. the flame of the burner and then enters the open.

end of the flue and passesthrough it to the blower flow as it flows in the direction of arrows a when;

entering and in the direction of arrow b when; discharging through the flue. This counterflow is important as it cools the burner supporting head and the adjacent portion of the outer shell which surrounds the combustion zone to such an extent that fire brick or similar insulation may be entirely eliminated. This reduces cost and weight and furthermore promotes combustion and overall efficiency.

The Venturi type burner] is provided with an air inlet head 9 and this i connected with the interior of the shell A by! means of a tube l0 which is provided with a valve ll so that a correct air and gas ratio 'may be maintained in the burner. Inasmuch as all air entering the shell of the heater must pass through the screen 8 there will be no dust or lint to coat the inner surface of the Venturi tube, this precludes faulty burner performance, furthermore, there is no lint to enter the combustion zone and all fire hazard is accordingly eliminated.

The main burner 1 i usually provided with a pilot burner such as indicated at I2. This burner may be installed in the sam manner as the main burner to prevent coating or clogging of its inner surfaces with lint or dust, or it may as here shown be installed within the shell where it is kept comparatively cool by the incoming air and where its air intake is open to the dust and lint free air within the shell.

The temperature of the air delivered to the cotton drier may be around five hundred degrees F. or more, but it may be delivered to the drier at any desired temperature by regulating the flame area of the main burner or by admitting additional cool air to flue 4 by means of a louver IA. The air entering at this point may or may not be screened as it is so far removed from the combustion zone that if-lint enters there is 'no danger of it becoming ignited and creating afirehazard. I Y

The heater as a whole is simple in construction and efiicient in operation. It does not require a heavy underpinning or foundation as it is comparatively light in weight due to elimination of fire brick or other insulation. Fire hazard is done away with due to the screening of all air and the main and pilot burners can be relied upon for continuousand efficient performance as no. dust lint can' accumulate on their interior. surfaces, and while this and other features of the heater have been more or less specificallydescribed and illustrated, it should be understood that changes may be resorted to within the scope-eithe-appended elongated cylindrical shell; a head" at eachend forming a closurethrefor; a Venturi-type" gas burner having its discharge end extending through one head, a discharge flue extending through the otheryhead said flue extending, through the length .of the, shell and terminating .in. front of the: discharge, of the burner but, being spaced therefrom and being. open toreceive the flame. of the, burner, .a screen covered .air'inlet formed-in the shelladj acent the other endofthe flue, and, a a blower connected with the. discharge flue to induce a flow .01, air lengthwise of the shell toward the burnersupporting head and .then in the reverse direction through the discharge flue. an air inlet-headon .the burner and 4 means for conveying air from the interior of the shell to the air inlet head of the burner.

2. In a heater of the character described a closed elongated shell, a discharge flue extending through one end of the shell and terminating at a point adjacent the opposite end but being spaced therefrom said terminating end being open, a Venturi type gas burner having its discharge end entering the shell and disposed in front of the open end of theflue to direct its flame into the line said burner having its gas and air inlet exterior of the shell, a pilot burner disposed wholly within the shell at one side of the discharge end of the first named burner, means for maintaining a flow of air from the opposite end of the shell towardwboth burners to cool the same and also to cool the portion of the shell surrounding .the'flame area of. the burners said air passing through the flame area and entering the open end of the flue and flowing in a reverse direction therethrough, means for conveying air from the interior of the shell to the air'inlet of the first named burner; and meansfor filtering all of the air entering the'shell.

TALLENT H; RANSOME.

References Cited in thefile of this patent "UNITED STATES PATENTS Number Name Date 286,301 Hequembourg .Oct. 9,. 1883 398,505 Gibbons Feb. 26, 1889 1,791,561 Heyn et a1 Feb. 10, 1931 2,077,043 Gehnrich' Apr. 13, 1937 32,386,115 vHolthouse Oct. 2, 1945 "2,445,059 Garretson July 13, 1948

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