US3771722A

US3771722A - Adapter for converting low pressure pilot burner for use with high pressure gas supply

Info

Publication number: US3771722A
Application number: US00240558A
Authority: US
Inventors: L Morris
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1972-04-03
Filing date: 1972-04-03
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13

Abstract

An adapter for converting a standard low pressure pilot burner for use with a high pressure gas supply including a fitting adapted to engage tubing for supplying the gas under high pressure and an orifice member of the pilot burner, the fitting carrying a pair of pressure reducing orifices interconnected by an elongated passage through the fitting.

Description

United States Patent Mo is 1451 Nov. 13, 1973 1 ADAPTER FOR CONVERTING LOW 9,396 11/1852 Wood 239/5903 PRESSURE PILOT BURNER FOR USE WITH z 5 2 2? i:

, a er HIGH PRESSURE GAS SUPPLY 522,088 6/1894 Shaw 239/5903 [75] Inventor; Louis P, Morris, Garden Grove, 917,998 4/1909 Buddington 239/590.3 X

Calif.

[73] Assignee: Robertshaw Controls Company, Primary Henson wood 11 Richmond, Assistant Examiner-John J. Love Filed A r 3 1972 Attorney-Anthony A. OBrien 21 A l. N 240,55 1 pp 0 8 57 ABSTRACT [52 us. 01 239/5903 239/590.5 239/596 adapter cnverting a Standard low Pressure 51 Int. Cl .7 liosb 1/00' Pilt burner use with a high Pressure gas sL'PPIY [58] Field of Search 239/590, 590.5, 590.3, duding a fitting adapted engage tubing Supply- 239/596 600 ing the gas under high pressure and an orifice member 4 of the pilot burner, the fitting carrying a pair of pres- [56] References Cited sure reducing orifices interconnected by an elongated f' UNITED STATES PATENTS passage through the ittmg 536,953 4/1895 Hughes et a]. 239/5903 15 Claims, 1 Drawing Figure BACKGROUND or THE INVENTION.

1. Field of the Invention The present invention'pertains to pilot burners and, more particularly, to a pilot burner adapted to permit utilization of pilot burners with gas supplied at high pressures.

2. Discussion of the Prior Art As is well known, many gas operated appliances including a main burner normally utilize a pilot burner to provide an ignition flame thereby rendering the burner continuously in condition for operation. Most gas supply lines utilized for such appliances deliver-gas at low pressures, and standard pilot burners are designed, for operation with gas. supplied at such low pressures in order to provide a pilot flame of predetermined size.

Recently, the number of gas appliances, being installed in multi-unit buildings, sometimes referred to as high rise apartments or office buildings, has substantially increased. It is desirable to utilize high pressure gas supplies for such buildings in order to provide adequate service and to reduce construction costs; however, standard low pressure pilot burners cannot properly operate under such high pressure conditions. Thus, the problem exists in the gas appliance field of having to vary construction of appliances, particularly pilot burners, dependent upon where the appliance is to be installed. z 7

At first glance, the above described problem appears to be of a simple natur'eand easilysolved; however, attempts to construct an adapter to permit use of standard low pressure pilot burners with high pressure gas supplies have not met with success in that there are practical limitations with respect to producing extremely small pressure reducing orifices, such adapter must preferably function foruse with non-candling tab type standard pilotburners thereby preventing the use of extremely long adapter passages, cost and complexity must be kept ata minimum, and installation must be facilitated in order to keep labor costs at' a minimum. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to construct an adapter for use-with a standard low pressure pilot burner-in order to convert such pilot burner for use with a high pressure gas supply.

The present invention is generally characterized in a pressure reducing adapter for converting a low pressure pilot burner for use with a high pressure gas supply, the pressure reducing adapter including a fitting adapted to be disposed between tubing for supplying the high pressure gas and an orifice member of the pilot burner and having an elongated passage therethrough, and a pressure reducing orifice carried by-the fitting in communication with the passage.

A further object of the present invention is to construct apilot burner adapter for modifying a standard pilot burner for low pressure gas of the inchesof water column order to operate with high pressure gas of the pounds per square inch order.

Another object of the present invention is to provide an adapter for reducing the pressure at'a pilot burner orifice sufficiently such that the pressure at-the pilot burner orifice corresponds to the nominal supply pressure for an inches of water column pilot burner.

' The present invention has another object in that noise accompanying the reduction of pressure from a high pressure gas supply to a low pressure required for a standard pilot burner is reduced to a minimal level.

A further object of the present invention is to construct a pressure reducing adapter for use with a standard low pressure pilot burner such that the adapter may be easily installed and is composed of a minimal number of parts thereby reducing labor and material costs. 7

Some of the advantages of the present invention over previous attempts to reduce the pressure at a pilot burner are that the components of the adapter of the present invention are of a simple design and may be easily manufactured,-the adapter of the present invention may be utilized with'non-candling tab type standard pilot orifice members and the adapter may be installed directly upstream of the pilot orifice member thereby facilitating installation thereof.

- Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a broken side elevation, partly in section, of a pilot burner adapter according to the present invention in combination with a main burner.

DESCRIPTION OF THE PREFERRED EMBODIMENT assembly 14. Bracket 12has an externally threaded nipple 16 depending therefrom adapted to engage an internally threaded nutl'8.'Nipple 16 has a cylindrical bore 20 extending from an outer end22 thereof to a flared inner end 24. I

Nut l8 has a cylindrical bore 26 therethroug'h to receive a p'iece'of tubing 28 adaptedto supply gas under high pressure to 'theburn'er' assembly 14; A beveled wall 30 extends from bore 26 to an internally threaded A wall 32 which engages nipple l6. Tubing 28 carries an annular ferrule 34-adjacent an end 36 thereof; ferrule '34 having a generally triangular configuration in cross sectionwith opposite sides 38 and. 40 meeting at a flat apex.

An orifice member 42 has a curved head 44-extending slightly above bracket 12 with a centrally disposed orifice 46 therein to permit gas effluence to support a pilot flame. Head 44 is aligned with outer end 22 of bore 20 through nipple l6 and terminates in a cylindrical wall 48 which extends through bore 20 and has a flared skirt50 extending outwardly therefrom to engage theflared end 24 of bore 20.

' As thus far described, the pilot burner assembly may be assembled for use with a low pressure gas supply by tightening nut 18 such that surface 40 of ferrule 34 seals against skirt 50 of orifice member 42 and surface 38 engages beveled wall 30 to provide a gas seal between tubing 28 and orificernernber 42. Accordingly, low pressure gas from tubing 28 will escape'through orifice 46 to support the pilot flame.

An adapter for modifying the pilot burner assembly 14 as thus far described for use with a high pressure gas supply isindicated generally at 52 and includes a fitting 54 having a central cylindrical body 56 with a neck 58 having an outer diameter substantially the same as the inner diameter of wall 48 of the orifice member 42. The outer surface of fitting 54 around body 56 defines an outwardly extending frusto-conical shoulder 60 adjacent neck 58, the configuration of shoulder 60 corresponding to the configuration of flanged end 24 of nipple 16 and skirt 50 of orifice member 42. An annular recess 61 is formed in fitting 54 within an annular collar or flange 62 depending from body 56. Flange 62 has a beveled edge 63 for sealably engaging surface 40 of ferrule 34.

Projections

64 and 66 extend centrally from opposite ends of body 56 and have grooves formed therearound by

annular ribs

68 and 70, respectively. A passage 72 extends longitudinally through the center of body 56 and

projections

64 and 66 to permit gas to flow through fitting 54. A small cup-shaped orifice member or spud 74 having a central orifice 76 is press fitted and rolled on projections 64 and held in place by a dimple engaging the groove formed by rib 68, and a similar small cup-shaped orifice member or spud 78 having a central orifice 80 is press fitted and rolled on projection 66 and held in place by a dimple engaging the groove formed by rib 70. 7

ln assembly, the fitting 54 is positioned between the orifice member 42 and tubing 28 such that shoulder 60, skirt 50 and flared end 24 of nipple 16 are in tight engagement, and the tubing 28 fonns a gas seal with fitting 54 due to engagement of surface 40 of ferrule 34 with beveled edge 63 of flange 62 of the fitting. With nut 18 screwed onto nipple 16, the entire pilot burner assembly is tightened to provide the required gas seal in order to prevent escaping gas.

The adapter 52 is, thus, easily assembled with a standard low pressure pilot burner in that the adapter need only be inserted between the standard tubing and pilot orifice member. That is, the nut 18 need only be loosened to separate the tubing 28 from the orifice member 42 and the adapter 52 inserted therebet'ween to convert a standard low pressure pilot burner for use with a high pressure gas supply. Tubing 28 desirably has end 36 chamfered to assure bottoming of the tubing in recess 61.

Once assembled the adapter 52 operates as a pressure reducer in that the high pressure of the gas upstream of the adapter in tubing 28 is reduced as gas flows through orifice 80, passage 72 and orifice 76 of the adapter. Accordingly, the pressure of the gas in the chamber 82 defined between adapter and orifice member 42 is reduced to the nominal low pressure required to provide a predetermined pilot flame fed by the effluence of gas through pilot orifice 46. The combination of pressure reducing'orifices 76 and 80 and the length of passage 72 provide the required reduction in pressure from pounds per square inch to inches of water column while maintaining noise at a low level.

In order to further reduce the noise level, the pressure reducing orifices of the adapter may be displaced from the longitudinal alignment shown in the FIGURE such that the pressure reducing orifices are not aligned; and, furthermore, one or both of the pressure reducing orifices can open at an angle to the longitudinal axis of the passage 72 through the fitting.

The pressure in the chamber 82 between the adapter 52 and the orifice member 42 can be controlled by varying the size of the

pressure reducing orifices

76 and 80. For example, when the supply pressure in tubing 28 is 10 psi, the pressure in chamber 82 can be reduced to 16.9 in. of water column by providing pressure reducing orifices 76 and each with a diameter of 0.010 in. with pilot orifice 46 having a diameter of 0.0 l 6 in.; and, with the supply pressure remaining at 10 psi, the pressure in chamber 82 can be reduced to 7.7 in. of water column by providing

pressure reducing orifices

76 and 80 with diameters of 0.010 in. and 0.008 in., respectively, while retaining the diameter of the pilot orifice 46 at 0.016 in.

The pilot burner adapter of the present invention may be provided with any suitable external configuration inorder to cooperate with various pilot burners, it being of primary importance only'that the adapter have an elongated passage and a pressure reducing orifice to reduce gas pressure in the tubing prior to supply to the pilot orifice. That is, while the external configuration of fitting 54 provides an advantageous gas seal with the pilot orifice member 42 and tubing 28, other configurations may be utilized dependent upon the configuration of the pilot burner support bracket and nipple and the fastening nut.

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter described above or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A pressure reducing adapter for converting a low pressure pilot burner for use with a high pressure gas supply, the pilot burner including an orifice member adapted to receive gas through tubing means; said adapter comprising a fitting having a central body adapted to be disposed between the tubing means and the orifice member of the pilot burner and. having first and second projections extending from opposite ends of said central body with an elongated passage extending through said central body and first and second projections, a first cup-shaped orifice member engaging said first projection .and carryinga first pressure reducing orifice,,and a second cup-shaped orifice member engaging said second projection and carrying a second pressure reducing orifice.

2. The pressure reducing adapter as recited in claim 1 wherein said first and second pressure reducing orifices are aligned with said passage.

3. A pilot burner assembly for use with a high pressure gas supply comprising tubing means adapted to supply gas under high pressure; i

pilot orifice means for establishing a pilot flame with gas under low pressure; and

pressure reducing adapter means interconnecting said tubing means and said pilot orifice means including a fitting engaging said tubing means with a gas seal, said fitting having a central body with first and second projections extending from opposite ends of said central body, elongated passage means extending through said central body and first and second projections, a first cup-shaped orifice member engaging said first projection and carrying a first pressure reducing orifice, and a second cupshaped .orifice member engaging said second projection and carrying a second pressure reducing orifice. I 4. The pilot burner assembly as recited in claim 3 wherein said pilot orifice means includes a member having a head with a pilot orifice therein and a cylindrical wall extending from said head and terminating at a flared skirt, and said central body of said fitting has a frusto-conical shoulder engaging and mating with said skirt.

5. The pilot burner assembly as recited in claim 3 wherein said fitting has an annular recess therein receiving said tubing means and an annular flange surrounding said recess and engaging said tubing means to provide a gas seal.

6. The pilot burner assembly as recited in claim 5 wherein said tubing means includes a ferrule disposed around the end thereof and having a surface for engaging said flange of said fitting. I

7. The pilot burner assembly as recited in claim 6 and further comprising a nipple having a central bore therethrough receiving said pilot orifice member and being externally threaded, and an internally threaded nut engaging said nipple, said fitting being disposed within said nut whereby the engagement of said nut and said nipple tightens said pressure reducing adapter means with said tubing means and said pilot orifice means.

8. An adapter for a pilot burner which includes a low pressure orifice means adapted for receiving gas through tubing means, comprising a fitting having a central body adapted to be disposed between thetubing means and the low pressure orifice means andhaving an elongated passage therethrough, v

a first orifice member on the-fitting having a first reducing orifice communicating from the tubing means to one end of the elongated passage, and a second orifice member on the fitting having a second reducing orifice communicating from. the other end of the elongated passage to the low pressure orifice means,

said passage between the one and other ends having a length which with the first and second reducing orifices provides a reduction in pressure from the tubing means to the low pressure. orifice means while maintaining noise at a low level.

9. A pressure reducing adapter for converting a low pressure pilot burner for use with a high pressure gas supply, the pilot burner including a threaded-nipple, a

low pressure orifice member having a skirt for extending from the nipple, an annular'ferrule on-an end of a high pressure gas supplying tube and a threaded nut surrounding the tube and the ferrule and adapted to screw to the nipple and to thighten the ferrule against the skirt to seal the tube to the low pressure orifice member; said adapter comprising a fitting adapted to be sealingly tightened by the nut and nipple between the tube and the low pressure orifice member, said fitting having (a) a shoulder for engaging the skirt, (b) an annular flange for engaging the ferrule, and (c) an elongated passage between the tube and the low pressure orifice member; and I pressure reducing orifice means carried by the fitting in communication with the passage.

10. A pressure reducing adapter as recited in claim 9 wherein said pressure reducing orifice means includes a first pressure reducing orifice at one end of the passage, and a second pressure reducing orifice at the other end of the passage. 5 11. A pressure reducing adapter as recited in claim 9 wherein the skirt is flared,

the shoulder is frusto-conical, and

the annular flange terminates in a beveled edge for engaging the ferrule.

12. A pilot burner assembly for use with a high pressure gas supply comprising tubing means adapted to supply gas under high pressure,

low pressure orifice means for establishing a pilot flame with gas under low pressure,

a pressure reducing adapter having a central body interconnecting the tubing means and the low pressure orifice means,

said adapter having an elongated passage extending between the tubing means and the low pressure orifice means, i

a first orifice member .on the adapter having a first reducing orifice communicating from the tubing means to one end of the elongated passage,

a second orifice member on the adapter having a second reducing orifice communicating from the other end of the elongated passage to the low pressure orifice means, and

said passage between the one and other ends having a length which with the first and second reducing orifices provides a reduction in pressure from the tubing means to the low pressure orifice means while maintaining noise at a low level.

sure gas supply comprising an annular ferrule on an end of a high pressure gas supplying tube;

a threaded nipple;

a low pressure orifice member having a skirt for extendingfrom the nipple;

a threaded nut surrounding the tube and the ferrule and adapted to screw to the nipple and to tighten the ferrule against the skirt to seal the tube to the low pressure orifice member;

a fitting adapted to be sealingly tightened by the nut and nipple between tube and the low pressure orifice member, said fitting having (a) a shoulder for engaging the skirt, (b) an annular flange for engaging the ferrule, and (c) an elongated passage between the tube and the low pressure orifice member; and i pressure reducing orifice means carried by the fitting in communication with the passage.

14. A pilot burner assembly'as recited in claim 13 wherein said pressure reducing orifice means includes a first pressure reducing orifice at one end of the passage, and a second pressure reducing orifice at the other end of the passage.

15. A pilot burner assembly as recited in claim 13 wherein the skirt is flared,

the shoulder is frusto-conical, and

the annular flange terminates in a beveled edge for engaging the ferrule.

13. A pilot burner assembly for use with a high pres-

Claims

1. A pressure reducing adapter for converting a low pressure pilot burner for use with a high pressure gas supply, the pilot burner including an orifice member adapted to receive gas through tubing means; said adapter comprising a fitting having a central body adapted to be disposed between the tubing means and the orifice member of the pilot burner and having first and second projections extending from opposite ends of said central body with an elongated passage extending through said central body and first and second projections, a first cup-shaped orifice member engaging said first projection and carrying a first pressure reducing orifice, and a second cup-shaped orifice member engaging said second projection and carrying a second pressure reducing orifice.

3. A pilot burner assembly for use with a high pressure gas supply comprising tubing means adapted to supply gas under high pressure; pilot orifice means for establishing a pilot flame with gas under low pressure; and pressure reducing adapter means interconnecting said tubing means and said pilot orifice means including a fitting engaging said tubing means with a gas seal, said fitting having a central body with first and second projections extending from opposite ends of said central body, elongated passage means extending through said central body and first and second projections, a first cup-shaped orifice member engaging said first projection and carrying a first pressure reducing orifice, and a second cup-shaped orifice member engaging said second projection and carrying a second pressure reducing orifice.

4. The pilot burner assembly as recited in claim 3 wherein said pilot orifice means includes a member having a head with a pilot orifice therein and a cylindrical wall extending from said head and terminating at a flared skirt, and said central body of said fitting has a frusto-conical shoulder engaging and mating with said skirt.

6. The pilot burner assembly as recited in claim 5 wherein said tubing means includes a ferrule disposed around the end thereof and having a surface for engaging said flange of said fitting.

8. An adapter for a pilot burner which includes a low pressure orifice means adapted for receiving gas through tubing means, comprising a fitting having a central body adapted to be disposed between the tubing means and the low pressure orifice means and having an elongated passage therethrough, a first orifice member on the fitting having a first reducing orifice communicating from the tubing means to one end of the elongated passage, and a second orifice member on the fitting having a second reducing orifice communicating from the other end of the elongated passage to the low pressure orifice means, Said passage between the one and other ends having a length which with the first and second reducing orifices provides a reduction in pressure from the tubing means to the low pressure orifice means while maintaining noise at a low level.

9. A pressure reducing adapter for converting a low pressure pilot burner for use with a high pressure gas supply, the pilot burner including a threaded nipple, a low pressure orifice member having a skirt for extending from the nipple, an annular ferrule on an end of a high pressure gas supplying tube and a threaded nut surrounding the tube and the ferrule and adapted to screw to the nipple and to thighten the ferrule against the skirt to seal the tube to the low pressure orifice member; said adapter comprising a fitting adapted to be sealingly tightened by the nut and nipple between the tube and the low pressure orifice member, said fitting having (a) a shoulder for engaging the skirt, (b) an annular flange for engaging the ferrule, and (c) an elongated passage between the tube and the low pressure orifice member; and pressure reducing orifice means carried by the fitting in communication with the passage.

10. A pressure reducing adapter as recited in claim 9 wherein said pressure reducing orifice means includes a first pressure reducing orifice at one end of the passage, and a second pressure reducing orifice at the other end of the passage.

11. A pressure reducing adapter as recited in claim 9 wherein the skirt is flared, the shoulder is frusto-conical, and the annular flange terminates in a beveled edge for engaging the ferrule.

12. A pilot burner assembly for use with a high pressure gas supply comprising tubing means adapted to supply gas under high pressure, low pressure orifice means for establishing a pilot flame with gas under low pressure, a pressure reducing adapter having a central body interconnecting the tubing means and the low pressure orifice means, said adapter having an elongated passage extending between the tubing means and the low pressure orifice means, a first orifice member on the adapter having a first reducing orifice communicating from the tubing means to one end of the elongated passage, a second orifice member on the adapter having a second reducing orifice communicating from the other end of the elongated passage to the low pressure orifice means, and said passage between the one and other ends having a length which with the first and second reducing orifices provides a reduction in pressure from the tubing means to the low pressure orifice means while maintaining noise at a low level.

13. A pilot burner assembly for use with a high pressure gas supply comprising an annular ferrule on an end of a high pressure gas supplying tube; a threaded nipple; a low pressure orifice member having a skirt for extending from the nipple; a threaded nut surrounding the tube and the ferrule and adapted to screw to the nipple and to tighten the ferrule against the skirt to seal the tube to the low pressure orifice member; a fitting adapted to be sealingly tightened by the nut and nipple between tube and the low pressure orifice member, said fitting having (a) a shoulder for engaging the skirt, (b) an annular flange for engaging the ferrule, and (c) an elongated passage between the tube and the low pressure orifice member; and pressure reducing orifice means carried by the fitting in communication with the passage.

14. A pilot burner assembly as recited in claim 13 wherein said pressure reducing orifice means includes a first pressure reducing orifice at one end of the passage, and a second pressure reducing orifice at the other end of the passage.

15. A pilot burner assembly as recited in claim 13 wherein the skirt is flared, the shoulder is frusto-conical, and the annular flange terminates in a beveled edge for engaging the ferrule.