Spraying apparatus
United States Patent 3902669

An apparatus for spraying refractory material in a wet slurry form on interior walls of soaking pits, blast furnaces, and the like with a spraying device which is attached to a movable boom or equal and is controllable from a location outside the interior of the structure being sprayed. The spraying device combines a liquid and a particulate material in a manner that the particulate material is sprayed on the interior walls of the structure. In addition, the spraying device is provided with an annular air nozzle which sprays compressed air in such a manner as to retain the sprayed material when applying the particulate material to the wall.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
118/303, 118/315, 118/323, 239/296, 239/588
International Classes:
B05B13/04; (IPC1-7): B05B3/12; B05B7/16; B05B15/06
Field of Search:
239/290,291,296,292,587,297,298,300,301,588,225,227,264,265 118
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Primary Examiner:
Wood Jr., Henson M.
Assistant Examiner:
Kashnikow, Andres
Attorney, Agent or Firm:
Petherbridge, Roy Lindgren Robert Gilhooly Edward E. L. D.
What is claimed is

1. An apparatus for spraying a mixture of particulate material in a wet slurry form on a wall comprising:


This invention relates in general to coating devices and, in particular, to an apparatus for spraying particulate material on the walls of a structure.

More specifically, the invention relates to an apparatus for spraying particulate material wherein there is included a spraying device which combines particulate material with a liquid such as water in a manner that the mixture is sprayed upon the interior walls of structures such as soaking pits and blast furnaces utilized in the steel industry. The spraying device is attached to an externally controllable boom or equal which permits the spraying device to be manipulated relative to the wall for completing coating thereof. In addition, the spraying device includes a novel pneumatic annular nozzle for directing an annular stream of compressed air controlling rebond of particulate material and the cleaning of the shell and cooler plates.

In the production of steel and similar industries, very large structures are utilized such as blast furnaces, soaking pits, and the like. During the continued use of these facilities, their inner walls tend to deteriorate to the point that their effectiveness can be impaired. Thus, coating materials are applied to these inner walls not only to repair damaged sections but also to apply protective coating on all portions of the wall in a manner that the useful lifetime is vastly extended.

A common substance utilized to coat the inner walls is a refractory material that provides extremely good resistance to deterioration in a high temperature environment of blast furnaces and is in the form of a particulate material. Thus, in order to facilitate adherence of this material to vertical walls and the like of a facility such as a soaking pit, it is necessary that water or other liquid be mixed in a slurry form and the mixture then ejected as a spray on the surface for adherence.

The prior art technique of applying the mixture to inner walls has been a time-consuming and costly process. The most common method of applying this material in the past has been through the use of a manually-held sprayer which requires that an operator be present within the blast furnace and the like during the spraying operation. Since soaking pits, blast furnaces and such structures are extremely large, the prior art technique of using hand sprayers required that scaffolds be built within the confines of the inner walls which had to be physically moved to cover the surface. The scaffold was in the form of a swinging structure suspended from a cable which was raised and lowered by means of a stationary winch. As the walls are sprayed, the scaffold had to be constantly lowered and raised and sometimes the hanging of the scaffold had to be modified to meet the constantly changing diameter of a blast furnace stack. The tedious process of supporting a man adjacent the wall was not only time consuming but definitely presented a dangerous safety hazard.

In addition to the problems of physically supporting a man adjacent the inner lining, the fact that the nozzle spraying the solution had to be manually held limited the size of the spraying device, which increased the time necessary to accomplish a given job. Another problem resulting from the prior art technique of spraying was the fact that the spraying device inefficiently applied the material to the walls whereby much of the particulate material would collect on the bottom of the facility which resulted in wasted material that had to be removed at a later time.


It is, therefore, an object of this invention to increase the spraying of material.

Another object of this invention is to increase the efficiency at which particulate material is applied to the wall of a structure.

A further object in the invention is to increase the spraying of material applied to walls of structures of large dimensions.

A still further object of this invention is to increase the efficiency at which particulate material is applied to the interior walls of large structures.

These and other objects are attained in accordance with the present invention wherein there is provided an improved apparatus for spraying a solution of particulate material for application to the walls of large structures such as blast furnaces, soaking pits, and the like. The apparatus includes a spraying device which is attachable to the end of a conventional boom or structure which permits the most manipulation of a spraying device to accomplish efficient spraying of material to the walls of the structure.

The spraying device of the invention combines a spray of water with the particulate material for application to the lining of the pit or furnace. The necessity for an operator of the apparatus to be within the furnace is eliminated whereby he is safely outside and can direct the spraying of material remotely. By being outside the area and without the necessity of being supported by a scaffold, hazards to personnel, which may be in violation of the Federal Occupational and Health Administration regulations is alleviated. Moreover, since the spray device is supported by a boom or structure, a significantly larger capacity device can be utilized for spraying a larger volume or increased flow rate of material actually increasing the tons-per-hour application rate.

This use of the boom or structure supported flow mixer of the invention not only eliminates the mixing equipment necessary when hand nozzles are utilized, but reduces the number of men required to apply the material. The apparatus of the invention is also provided with a pneumatic annular nozzle positioned adjacent to the sprayed solution whereby the compressed air flow directed from the nozzle controls the application of the material to limit the area the particulate material is deflected so that increased and more efficient coating of material is applied to the lining for an elimination of the build-up of uncoated material.


Further objects of the invention, together with additional features contributing thereto and advantages accrueing therefrom, will be apparent from the following description of an embodiment of the invention when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a prospective side illustration of the apparatus for spraying material of the invention mounted adjacent to the wall of a soaking pit;

FIG. 2 is a side schematic illustration of the spraying device used in the apparatus of the invention;

FIG. 3 is an end schematic illustration of the spraying device of FIG. 2; and

FIG. 4 is a perspective illustration of the spraying device of FIG. 2.


Referring to the FIGS. 1, 2, and 3, there is illustrated the apparatus of the invention for spraying material on the interior walls of structures. Although not intended to be so limited, for convenience of illustration the apparatus is shown in FIG. 1 in operative position within a conventional soaking pit utilized in the production of steel. The spraying apparatus 1 of the invention is mounted within the soaking pit by means of a boom means 2 which permits upward, downward, and lateral manipulation of the spraying device from a location external to the soaking pit.

Spray apparatus 1, is easily adapted to any boom means such as, for example, the boom 2 supporting a hammer 3 for removing slag from the wall 4 of soaking pit and the like. The boom is mounted on turret 5 for 360° rotation and hydraulic means 6 permits the boom to be lowered or raised. Boom is telescopic in form and the lower portion 2a with pivotal hammer 3 can, therefore be raised or lowered. Any suitable means is utilized to attach the apparatus directly to the slag hammer.

Referring now to FIGS. 2 and 3, there is illustrated the novel spray apparatus of the invention for applying a refractory material to the walls 4 of soaking pit. Apparatus 1 includes a mixing housing 10 having an interior passage 10a which is coupled to a conventional nozzle element 11. An inlet coupling 12 is attached to the other end of the passage of housing 10 and is adapted to be attached to a particulate material supply hose (not shown) which delivers particulate material into the housing for spraying against the wall of the soaking pit. The supply conduit supplies particulate material and the like to inlet 12 and is adapted to be attached to any conventional pressure source which permits the delivery of particulate material from a location exterior of the pit. The hose can be coupled to boom 2 in any desired manner.

As best shown in FIGS. 3 and 4, housing 10 is also coupled to a pair of liquid conduits 15 which are adapted to supply a liquid such as water to interior passage 10a under pressure in a manner that the flowing particulate material supplied to passage 10a and water mix to be ejected through nozzle 11. The mixing of the liquid and the particulate material in housing 11 can be achieved in any conventional manner. The flow of water or other liquid through pipe 14 can be controlled by an electrically actuated control valve 15 operable from an external position to regulate the amount of flow and flow rate of the liquid and thus fluid mixture ejected by nozzle 11.

From the foregoing it should be apparent that the particulate material introduced into housing 10 through inlet 12 and the liquid introduced at two locations into housing 10 through pipes 14 intermix in a known manner and as a mixture flow outward through nozzle 11 for delivery to the wall. Mixing chamber 10 is mounted on a support structure 21 which is retained on a turret element 22. Turret 22 is operably connected by a shaft means to an electric gear motor or variable speed motor 23 supported within a box 23a to effect rotational movement of the turret to control the direction of flow being ejected by nozzle 11.

The rotational movement of turret 22 can be controlled from the exterior by an operator controlling the operation as outlined previously. Apparatus 1 is supported by means of a removable bracket 24 which is secured to hammer 3 of boom means 2 and can be removed and attached thereto in a conventional manner. A pneumatic nozzle means 35 is also attached to turret 22 and includes an upright pipe 31 coupled to a connector element 32. An inlet pipe 33 delivers a supply of compressed air, for delivery into upright pipe 30.

A lateral pipe 34 is suitably coupled to the upper end of pipe 30 and includes a nozzle 35 means having a plurality of jets 36 encircling the area being sprayed to direct the stream of air in vicinity and direction that the refractory material is being sprayed by nozzle 11. The stream of compressed air creates a conical pattern encircling the area of the spray of refractory material 11 which achieves significantly improved adherence of particulate material to the lining and eliminates build-up of unattached material at the bottom of a pit and elsewhere which appears in the prior art techniques of coating walls. The presence of the pneumatic spray prevents the formation of a cloud of refractory material which can occur during a spraying operation.

In operation, an operator of the spray apparatus of the invention is situated exeriorly of a furnace or soaking pit on a platform or otherwise and can follow the application of the refractory material visually or through closed circuit TV or holes cut in the lining of the blast furnace. The operator also is able to control not only the flow of particulate material through the nozzle, but is also able to introduce the right amount of water by means of electrically controlled water valve 15. Because of the mounting of the fluid control device upon the boom or support means 2, the relative moveability of the manipulator and the rotational movement provided by turret 22, the material sprayed by the nozzle can be moved up or down, angularly, and rotated through a circular angle of 360°.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for the elements thereof without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teaching of the invention without departing from its essential teaching.