# US 4,397,633 A · Fuel oil heater

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- Number: US 4,397,633 A
- Document ID: US4397633A
- Status: Granted
- Kind: A
- Application number: 06/296,673
- Filed: 1981-08-27
- Granted: 1983-08-09
- Earliest claimed: 1981-08-27
- Inventors: Charles G. Rowlee
- Web page: https://patentgrep.com/patent/US4397633A

## CPC

- F23K 5/20: Preheating devices (in burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space F23D11/44)
- Y10T 137/6416: With heating or cooling of the system
- F23K: FEEDING FUEL TO COMBUSTION APPARATUS (fuel feeders specially adapted for fluidised bed combustion apparatus F23C10/22)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Apparatus for heating the fuel oil exiting from an oil supply tank and in the supply pipe leading to an oil burner furnace. The return oil line, from the pressure relief valve in the oil burner unit, is led to a coil fitted about the furnace stack leading from the oil burner furnace. The outlet of this heating coil is then led into a metal tempering box, mounted below the tank, through a pipe banded to the supply pipe so as to warm the oil in the supply pipe and the oil in the tempering box. Supply oil is fed from the oil supply tank into the tempering box, to mix with the heated oil in the tempering box, with the mixed warmed oil led from the tempering box into the supply pipe leading to the oil burner of the furnace.

## Claims

### Claim 1

Apparatus for heating the fuel oil that is supplied to an oil burner furnace, where the oil burner furnace is fitted with an oil burner unit that pumps oil from a supply line leading from a fuel tank into an oil burner nozzle and also pumps oil through a pressure relief valve to an oil return line, and where the furnace is fitted with a stack to carry hot exhaust furnace gases to a flue comprising
means to heat the oil in the return line utilizing the heat of the exhaust gases of said stack, and
means to heat the oil in the supply line utilizing the heat of the oil heated in the return line.

### Claim 2 (depends on 1)

The invention recited in claim 1 in which the means to heat the oil in the return line comprises a coil mounted about the stack, which coil is fitted between the section of the return line leading to the fuel tank and the section of the return line leading from the oil burner unit.

### Claim 3 (depends on 1)

The invention as recited in claim 1 in which the means to heat the oil in the supply line comprises mounting together sections of the supply line and the return line leading from the fuel tank to the oil burner unit along a substantial portion of their length.

### Claim 4 (depends on 1)

The invention as recited in claim 1 in which the means to heat the oil in the supply line comprises a hollow tempering box, with the return line leading from the means to heat the oil in the return line into said tempering box, and with the supply line extending from the interior of said tempering box to the oil burner unit, with an outlet of the fuel tank extending into the said tempering box.

### Claim 5 (depends on 4)

The combination as recited in claim 4 in which the tempering box is mounted below the fuel tank, and enclosed in thermal insulation.

### Claim 6 (depends on 3)

The combination as recited in claim 3 in which the said sections of the return line and supply line are clamped together and enclosed in thermal insulation.