US2361252A - Flow heater - Google Patents

Description

R. E. WELCH Oct. 24 1944o FLOW HEATER Filed Feb. 2, 1942 3 Sheets-Sheet 2 ocr. 24, 1944e R," E. WELCH 2,361,252

FLOW HEATER Filed Feb. 2. 1942 5 Sheets-Sheet 3 RQbewEx/zch,

Patented Oct. 24, 1944 UNITED STATES PATENT oFricE FLOW HEATER Robert` E. Welch, Houston,l Tex., assignor to Nowery J. Smith, doing business as, Nowery J. Smith Supply Company, Houston, Tex.

Appiication February 2, 1942, serial No. A429,351

(c1. cs2- 1) 2 Claims.

The present invention relates to a flow heater for oil Wells.

It is a principal object of the invention to provide suitable apparatus for heating the high pressure wet gas as it flows -directly from theoil weil.

A further object of the invention is to provide apparatus fory automatically heating the high pressure wet gas ilow from an oil well, so that a denite temperature of the oilwell flow may be maintained after the high pressure flow has been reduced to a pressure suitable for separating.

Many oil wells in use today produce a very high pressure wet gas, the pressure of which must be greatly reduced before it can be separated into its components of oil, water, and gas. Itis common practice to heat the high pressure flow from the well, so that the ow will not freeze when the pressure is reduced, in view of the scientific fact that reducing the pressure of a gas also causes a cooling of the temperature of the gas. If the high pressure flow from the well were reduced in pressure at well temperature, great diiliculty would be experienced, because the iiow wouldfreeze and the pressure regulating valves would freeze. By my invention, I have provided an oil well flow heater ,which is automatically regulated so that a deiinite and controlled temperature j of flow at reduced pressure is obtained, and the 'possibility that the iiow will freeze and the/pressure regulators freeze is avoided.

- It is a further object of my invention to provide an oil well ow heater construction, in which the supply of fuel to the heater burners is thermo- Y statically controlled in response to thetemperature of the heated oil well flow after pressure reduction. p

Further objects and advantages of the invention will be readily understood from the accompanying description and drawings, in which:

Figure 1 is an elevation of the complete heater apparatus, including the pressure reducing regulators and the thermostatic` burner controls; y

Figure 2 is a vertical section of the heater tank, showing the) burner, ilues, and iiow conducting pipe or coil partly in elevation;

Figure 3 is a cross sectional view taken on\the line 3 3 of Figure 2, showing the details of the u able manner.

of the float controlled water supply to the upper water compartment of the heater.

Referring to the drawings, in which like n merals indicate like parts, i indicates generally the'vertical upright tank comprising the main heater structure. The vertical tank i is divided into an upper water-containing compartment 2 and a lower rebox compartment 3 by a iianged and dished steel head d, constituting the domeshape'd head of the rebox. Extending from the steel head 4 through the upper water-containing compartment 2are a series of flues orre tubes 5. These tubes extend above the level of the water in the compartment 2 and communicate with the atmosphere through the hood and chimney structure 6. Positioned within the upper water-containing compartment 2 Vand coiled in proximity to the iiues 5, is a flow conducting` pipe 1. This pipe enters the tank at 8, and is provided `on the inlet side with a cut-'off valve 8a., by means 4of which the flow conducting/,pipe 'i may' be valved andconnected to the source of high pressure flow from the well. The flow conducting pipe 1 is provided with the outlet pipe 9 for conducting the heated ow to the pressure reducing and regulating valve `2i` to be described hereinafter.

Positioned within the rebox 3 are a plurality of low pressure vgas burners Ill. These burners are nested in a group in the center of the rebox and y are'llsupplied with a source of warm dry gas as fuel, by means of the fuel supply pipe I l A pilot burner I2 is also provided, which ls intended to be burning at all times and is supplied with fuel through the pipe I3. Air supply tubes I4 for the burners are positioned in the bottom of the firebox and are provided with damper valves i5 to control the amount of 'air supplied to the burners. These damper valves are shown as manually oper` ated, although they may be operated in any suit- A irebox door i6, by means of which access to the rebox may be had, is shown in Figure 1 of the drawings.

The upper water-containing compartment of the heater is supplied with water through the positioning of the burner iiues within the tank; the level of the water line is an overow pipe vFigure 4 is a cross sectional view taken on the line 4 4 of Figure 2, and showing the details of the burners and the air supply tubes in the fhebox,

and

Figure 5 is a fragmentary view, showing a detail opening I8, which will carry away any excess amount of Water in the tank, should the float operated valve l1 fail to function. The upper compartment 2 is also provided with a waterlevei sight gage i9, and a thermometer 20, by means of which conditions of the water in the upper compartment may be ascertained.

The heated high pressure oil well flow, after passing through the ow conducting pipe or coil 1, is conducted through the outlet pipe 9 to the pressure regulator valve, indicated generally at 2| where its pressure is reduced to the desirable pressure for further treatments, such as separating or the like; In order to make repairs on the pressure regulator, should they be necessary, a by-pass system is provided to shunt the iiow around the pressure regulator. Valves 22, 23, and 24, together with a piping 25, constitute the by-pass arrangement, and it can be readily seen that by closing the valves 22 and 24. and opening the valve 23, the iiow will be by-passedv around the pressure regulator.4 After leaving the pressure regulator, the flow is conducted through the pipe 26 to the thermowel 21, which contains the actuating bulb 28 of the thermostat valve 29 controlling the fuel supply to the burner I0. A temperature indicator 49 is positioned onv the thermowel 21 to indicate the temperature of the reducedl pressure oil well ow. 'I'he treated iiow then passes through the pipe 30 to the separator apparatus or other apparatus, which is desired to be used to treat the oil well flow.

' The low pressure burners l0 lused in this apparatus are supplied with gas as a fuel, of which there is a great abundance in most oil fields, and this gas is usually cold and of high pressure. Y It is, therefore, necessary to warm the fuel gas and reduce its pressure, andi I have provided in my invention apparatus for performing this function. The cool dry fuel gas is supplied through the pipe 3| and passes through a hairpin coil 32 withinA the upper water-containing compartment rof the heater, whereby the fuel gas is warmed. The fuel gas then passes through a pressure regulator 33 and the,pipe`34 to the pressure reducing apparatus. In view of the high pressure of the gas, I have provided two pressure reducing regulators 35 and 36 to reduce the fuel gas to the very .lowV pressure needed for the low pressure burners 4lll. The yhigh pressure lfuel gas first passesthrough the pressure regulator 35. A T

fitting A31 is provided to branch the reduced pressure fuel gas into two lines. Some of the reduced pressure gas is conducted through the pipe 38 and the shut-off valve 39 to the pipe I3 which supplies the pilot burner-with fuel. A pressure indicator 4D is shown to indicate the pressure ,of the fuel supply to the pilot. 'I'he warmed dry gas 31 through thek pipe 4| to the .pressure regulator 38. This further reduces the pressure of the fuel gas so that it islow enough to properly burn in the' low pressure burners. pressure fuel gas is conducted through the pipe 42 from the pressure regulator 3B to the thermostatically controlled valve .29 which is responsive to the temperature of the oil well flow as it passes the thermowel y21. Theithermostatically regulated low pressure fuel gas as supplied by the thermostatic valvey29, then passes throughthe This warm and low the pressure regulator 38 and thermostatic valve 29. A press'ure indicator 41 may be used to indicate the pressure vof the fuel gas supply to the low pressure burners.

The pressure regulator 2| for reducing the pressure of the heated high pressure oil well ow is of 'the standard construction operated by diaphragms, and in order to prevent freezing, is supplied with asource of warm highpressure gas conducted through the tubing l48 connected to the down-stream side of the hairpin coil 32. The warm dry gas conducted through the tube 48 is used to operate the diaphragms in the pressure regulator 2|, and thus minimize the possibility that the pressure regulator will freeze.

As the pressure4 regulator valves, shut-off valves, thermowel, and thermostatically-controlled valve are all of standard manufacture, it will be readily understood that my invention is not limited to the use of any specific forms of these mechanisms, but that any suitable substitutes may be used.

In operating my flow heater, the flow from the oil wells which is mainly a high pressure wet gas, is conducted through the iiow conducting pipe 1 coiled within the upper water-containing compartment 2. This coil is in proximity to the rebox tubes or fiues 5, and the heat of burning gases passing through the flues 5 will be transmitted through the water in the upper compartment 2 to the coil 1. This results in a heating of the high pressure wet gas flowing through the coiled pipe 1. The heated high pressure flow then passes through the outlet pipe 9 to the pressure reducing regulator 2|. After the pressure of the heated oil well ow is reduced the temperature of the reduced pressure flow is obtained. The thermowel 21 and the actuating bulb 28 of the thermostatically-controlled valve 29 are operated in response to this temperature of the reduced pressure flow. The thermostatic valve 29 controls the operation of the burners I0 which supply the heat to the upper water 'i at reduced pressure also passes from the T fitting compartment 2, and hence to the high pressure wet gas flow from the well.

'I'hus it'will be seen that I have provided apparatus for heating the high pressure flow from an oil well and controlling the amount of heat supplied to said high pressure flow in accordance with the temperature of the reduced pressure flow, so that a definite temperature of reduced pressure flow may be maintained. By operating my thermostatic valve on the fuel supply to the burner in response to the temperature ,of the reduced pressure oil well flow, I canvobtaina denite control of the temperature of the reduced oil well flow as it passes the outlet pipe 30.

`In the appended claims, the term fiow" is intended to mean the Wet gas flowing directly from oil and gas wells.

I claim:

1. In an apparatus of the character described, an upright tank having an upper water compartment and a lower firebox compartment, a burner in said rebox. a series of vertical flues extending from the firebox compartment through the water compartment to communicate'with the atmosphere, a line including a flow conducting pipe coiled in proximity to the flues within said upper compartment, said line being adapted 'to be connected to a' source of high pressure gas flow from an oil well, pressure reducing means in said line beyond said tank, and means Vto control the supply of fuel to the burner in said,-

to the temperature in said line beyond said pressure reducing means.

2. In an apparatus ofthe character described,

, a line adapted to be connected to an oil wel] to receive warm high pressure gas from the latter, a pressure reducer in said line, a second line adapted to be connected to a source of cold high pressure gas, gas-tired means to heat said second line and to also heat said first-named line at a point in advance of said pressure reducer, said second line leading to said heating means to supply gas fuel to the latter, and temperature responsive means in said first-named line beyond' said pressure reducer to control the flow in said second line.

ROBERT E. WELCH.

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