US 3606168 A
Description (OCR text may contain errors)
Sept. 20, 1971 H. J. SEAMAN, JR
RECIRCULATING SPRAY NOZZLE Filed Dec. 27, 1968 Jm/awzor 4 4mg Jam yr.
United States Patent Office 3,606,168 Patented Sept. 20, 1971 3,606,168 RECIRCULATING SPRAY NOZZLE Harry J. Seaman, Jr., Milwaukee, Wis., assignor to Seaman Corporation, Milwaukee, Wis. Filed Dec. 27, 1968, Ser. No. 787,329 Int. Cl. B05b 1/00 US. Cl. 239-597 6 Claims ABSTRACT OF THE DISCLOSURE A spraying apparatus for heated bituminous material including a spray bar divided by a horizontally disposed partition into inlet and outlet flow passages and a number of spray valves mounted on the spray bar, each spray valve having an inlet port connected to the inlet flow passage in the spray bar, an outlet port connected to the outlet flow passage in the spray bar and a spray port open to the atmosphere and a valve plug having a flow passage terminating in a spray nozzle port, the valve plug being mounted for rotary motion in said valve to selectively connect the flow passage to the inlet port and to either the outlet port or the spray port.
BACKGROUND OF THE INVENTION Bituminous material used for road surfacing must be heated to reduce the viscosity of the material sufficiently to permit the material to be sprayed evenly through the spray nozzle ports in the spray valves. As long as the bituminous material remains heated, it will flow freely through the spray valves. However, when the spray valves are closed, the material in the valves begins to cool and solidify, partially blocking the passages in the spray valves causing bare spots and/or streaks the next time the spray valves are opened. A recent improvement is the recirculating type spray bar in which the material continues to circulate through the spray bar when the valves are closed. This helps to keep the spray bar warm, but the spray valves must depend on heat transfer from the spray bar to maintain spraying temperature. This function is impeded by the presence of a gasket between the spray valve and the spray bar which is normally used to prevent leakage. The gasket acts as an insulation reducing the amount of heat transferred to said spray valves.
The bituminous material must be sprayed onto the road surface at a constant rate generally measured in gallons per square yard of road surface. If the rate is too high, material is wasted and if too low, the road surface will fail. In a recirculating type spray bar, the spray valves are bypassed and the bituminous material is recirculated through the spray bar only. During the periods of recirculation, the pump engine speed control is adjusted to provide the required flow rate based on the load produced by the spray bar. ;When the spray valves are opened, a change in load occurs resulting in a change in flow rate and a discrepancy in the amount of material sprayed onto the road surface until the engine speed con trol adjusts to the new load condition. The spray fan from the spray nozzles must be set to provide sufiicient overlap for proper coverage of the road surface. In spray valves having a separate nozzle screwed into the valve body, adjustment of the spray nozzle is often required due to vibration in order to maintain the proper relation of the spray fans. Too much overlap results in a waste of bituminous material while too little overlap will result in a poor road surface.
SUMMARY OF THE INVENTION The spraying apparatus of this invention provides a continuous flow path for the bituminous material through the flow passages of the spray bar and the spray valve and nozzle assemblies during both spraying and recirculating of bituminous material through the spray bar. Each of the spray valve and nozzle assemblies is provided with inlet and outlet ports connected directly to the inlet and outlet flow passages in the spray bar and a spray port for spraying heated bituminous material onto the road surface. Flow of heated bituminous material through the spray valve and nozzle assemblies is controlled by valve plugs having flow passages terminating in spray nozzle ports, the valve plugs being selectively moveable to connect the inlet port to either the spray port or to the outlet port through the flow passages in the valve plug. By maintaining a continuous flow of heated bituminous material through the spray bar and spray valve and nozzle assemblies, the spraying apparatus including the spray valve and nozzle assemblies, the spraying apparatus including the spray valve and nozzle assembly will always be at a high enough temperature to heat the material passing through the assembly and will prevent the congealing of bituminous material in the spray valve passages.
This spraying apparatus also provides a constant flow of bituminous material when the valve plugs are moved from the recirculating to the spraying positions due to the continuous flow of bituminous material through the spray nozzle ports provided in the valve plugs. The load on the pump will be determined by the spray nozzle ports and will remain the same Whether the bituminous material is recirculating through the spray bar or is being sprayed onto the road surface. The continuous flow of bituminous material through the flow passage in the valve plug prevents the bituminous material from congealing in the flow passages and thereby eliminates the possibility of streaking.
A further advantage of this spray valve nozzle assembly is that, due to the spray orifice being an integral part of the valve plug, the angle between the plane of the spray fan and the spray bar with'respect to the vertical axis will always remain constant. This is quite important since too small an angle will cause interference of adjacent spray fans, and too great an angle will produce too fnarrow a coverage and insufiicient overlap of spray ans.
Other objects and advantages of the present invention will become apparent when read in connection with the accompanying drawings, in which:
FlG. 1 is a schematic view of the circulating system for the heated bituminous material connected to the spraying apparatus.
FIG. 2 is a front view in section of one of the spray valves showing the how path of the heated bituminous material through the spray valve.
FIG. 3 is a side view taken on line 33 of FIG. 2 showing the valve plug for the spray valve.
FIG. 4 is a bottom view of a portion of the spray bar showing the angular relation of the spray nozzle port to the spray ibar.
DESCRIPTION OF THE INVENTION Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.
Referring to the drawing, the spraying apparatus 10 of this invention is shown connected to a recirculating system 12 for a bituminous material 14 which has been heated by conventional means in a reservoir 16. The heated bituminous material 14 is pumped through the circulating system 12 to a spray bar 1-8 and recirculated through the spray bar or sprayed onto a road surface by means of a number of spray valve and nozzle assemblies 20. The flow of the bituminous material 14 through the spray assemblies 20 is controlled by means of valve plugs 22 each of which has a flow passage 24 terminating in a spray nozzle port or orifice 26. The valve plugs 22 are selectively move'able to provide a spray path or a recirculating fiow path through the spray assemblies 20.
The heated bituminous material 14 in the reservoir 16 is continuously circulated through the spray bar 18 and back to the reservoir 16 by means of a pump 28 connected to a suction pipe 30 positioned in the reservoir 16 and to a pressure pipe 32 connected to the spray bar 18 by a hose 34. Control valves 36 and 38 are provided in the suction pipe 30 and the pressure pipe 32, respectively, to allow for filling or draining of bituminous material to the reservoir 16. The heated bituminous material 14 is returned from the spray bar 18 to the reservoir 16 through a hose 40 connected to a pipe 45. The bituminous material is circulated through the recirculating system 12 Without passing through the spray bar 18 by means of a bypass valve 42 connected to a three way pipe fitting 44 in pressure pipe 32 and a three way pipe fitting 46 in return pipe 45. The flow of bituminous material to the spray bar 18 is controlled by control valves 48 and 50 provided in pressure pipe 32 and return pipe 45, respectively.
The spray bar 18 is divided into an inlet flow passage 52 and a return flow passage 54 by means of a horizontally disposed partition 56. Circulation of bituminous material from the inlet flow path 52 to the outlet flow path 54 in the. spray bar 18 is achieved by means of the spray valve and nozzle assemblies 20 mounted on the outside of wall 58 of the spray bar 14. Each of the spray assemblies 20 includes a housing 60 secured to the outer Wall 58 of the spray bar 18 by means of bolts 62. leakage of bituminous material between the housing 60 and wall 58 is prevented by means of a gasket '64 positioned between the housing 60 and the wall 58. The housing 60 includes a central chamber 66 which is connected to the inlet passage 52 through a port 68 in Wall 58 and to the return passage 54 through an outlet port 70 in wall 58. A spray port 72 is provided in the lower part of the housing 60' to allow the bituminous material to be sprayed onto a road surface.
The flow of bituminous material 14 through the housing 60 is controlled by means of the valve plugs 22 which are mounted for rotary motion within the housing 60. The valve plugs 22 include an annular body portion 74 positioned within chamber 66 and a hub 76 positioned in well 78 in the housing 60 with a valve stem 80 projecting outwardly through an aperture 82 in housing 60. The valve plugs are sealed within the chamber 66 of the housing 60 by means of an O-ring 84 positioned in a groove 86 in the outer periphery of the hub '76. The valve plugs 22 separate the inlet port 68 from the outlet port 70 and the spray port 72. The inlet port 68 is selectively connected to the outlet port 70 or to the spray port 72 by rotating the valve plug 22 to align the passage 24 in the valve plug 22 with the inlet port 68 and either the outlet port 70 or the spray port 72.
The valve plugs 22 can be rotated manually by means of a common actuating bar 88 connected to the valve stem 80 by a radially extending arm 90. The actuating bar 88 is moved relative to the spray bar 18 to rotate the valve stems 80 to align the flow passage 24 in the annular body portion 74 with the ports in the housing 60.
The bituminous material 14 is sprayed onto the road surface by means of the spray nozzle port or orifice 26 provided at the end of the passage 24. The spray nozzle port 26 converges inwardly near the end of the flow passage 24 and then diverges outwardly to an elongated slot 92. An even distribution of bituminous material is produced across the full width of the spray bar 18' by means of the angular relation of the slot 92 to the axisEM of the spray bar 18. The spray bar of the adjacent spray valve and nozzle assemblies 20 will overlap sufli'ciently to produce a continuous spray of bituminous material across the full width of the spray bar. This angular relationship can be seen in FIG. 4 where the longitudinal axis 96 is shown intersecting the axis 94 of the spray bar :18 at an angle of 15 to 30. Since this relationship is fixed due to. the location of the slot 92 in the valve plug, a continuous spray will be produced each time a spraying operation is started.
In operation, the bituminous material is heated in the reservoir 16 and pumped through the circulating system 12 when heated sufficiently to become flowable. Valves 4-8 and 50 are then opened and valve 42 closed to circulate the bituminous material through the spray bar 18 and spray valve and nozzle assemblies 20. The actuating bar 88 is then moved to rotate the valve plugs 22 to align the passage 24 with the inlet port 68 and the spray port 72. When the spraying operation is completed, the actuating bar 88 is moved to rotate the valve plug 22 and align the passage 24 with the inlet port 68 and outlet port 70. A continuous flow of bituminous material 14 will then pass continuously through the spray valve and nozzle assemblies 20 whenever the spray apparatus is being used.
A continuous load is imposed on the pump 28 by locat ing the spray nozzle port 26 at the end of the flow passage 24 in the valve plug 22. The bituminous material will flow through the nozzle 26 when the material is recirculating as well as when the material is being sprayed onto a road surface.
Although only a single spray bar 18 is shown in the drawing; it should be apparent that the spray bar is adaptable to a variety of different spraying structures where the material to be sprayed must be kept in constant motion.
What is claimed is:
1. A spraying apparatus comprising a spray bar having an inlet flow passage and an outlet flow passage, and
a number of spray valves mounted on said bar, each of said valves including a valve plug-for selectively connecting said inlet flow passage either to said outlet flow passage or to a spray port diverging outwardly from said valve plug.
2. An apparatus according to claim 1 wherein said valve plug includes a flow passage having a converging outlet.
3. An apparatus according to claim 1 wherein each of said spray ports are angularly oflset from the longitudinal axis of said housing.
4. An apparatus according to claim 10 wherein said spray ports are angularly offset from the longitudinal axis of said housing to produce overlapping shaped sprays of bitumen.
5. An apparatus according to claim 1 including means for simultaneously moving said valve plugs in said spray valves.
6. An apparatus for spraying heated bituminous material comprising a spray bar,
a partition dividing said spray bar into an inlet flow passage having a number of inlet ports and an outlet flow passage having a number of outlet ports,
a number of spray valves mounted on said spray bar,
each of said spray valves including a housing having a central chamber enclosing one of said inlet ports and one of said outlet ports and an elongate diverging spray port,
a valve plug mounted in said chamber in each of said housings to separate the inlet port from said outlet port and said spray port,
said valve plug including a flow passage having a converging outlet, and
6 means for moving said .plug to connect said flow passage 1,325,513 12/1919 Fricker 239--59'8X in said valve plug with said inlet port and either said 2,256,639 9/ 1941 Erickson 239--124 outlet port or said spray port. 3,120,927 2/1964 Holland 2339-172X References Cited: UNITED STATES PATENTS 3,043,518 7/1962 Cartwright L 239-424 3,106,937 10/ 1963 Sands 239-124X 3,268,176 8/1966 OBrien et a1 23-9-536X 5 ALLEN N. KNOWLES, Primary Examiner T. C. CULP, JR., Assistant Examiner