US1704623A

US1704623A - Refractory gun

Info

Publication number: US1704623A
Application number: US252806A
Authority: US
Inventors: Gerald P Mcmanamna
Original assignee: MCCRAKEN RIPLEY CO
Current assignee: MCCRAKEN RIPLEY CO; MCCRAKEN-RIPLEY Co
Priority date: 1928-02-08
Filing date: 1928-02-08
Publication date: 1929-03-05
Anticipated expiration: 1946-03-05

Description

Mrfch 5, 929,

' G. P. MCB/IANAMNA REFRACTORY GUN Filed Feb. 8, 1928.

Patented Mar. 5, H92@ UNH@ STATES retenir ernten GERALD P. MUMNAMNA, OF PORTLAND, OREGON, ASSIGNOR TO MCCRN-REPLEY C0., OF PORTLAND, OREGON, A CORORATON OF OREGON.

nnrnacfronv een.

Application led February 8, 1928. Serial No. 252,806.

My invention relates especially to. the socalled refractory guns having for lts purpose the spraying of a plastic material upon the walls of a combustion chamber, for relining the same and restoring them to function properly after having been worn away in service.

My invention incidentally relates to devices employed for coating any wall surface with a cementitious material.

The average boiler or industrial furnace burns out the re brick lining at the rate of one-fourth to one-half an inch a month, in the heavy duty zones or parts of the furnace where the greatest wear takes place; and some furnaces will double this average wear.

The re-surfacing of the re brick lining when done by hand is a slow process, and so there has, heretofore, been devised a socalled refractory gun which was employed for applying the spray or coating of the plastic material to restore the burnt away wall surfaces; and such refractory guns d-o the work better than can be done by hand.

But these devices, as known to me, do not work satisfactorily nor efficiently, because it is necessary to make the plastic mixture with an excess of water, in order to render it thin enough for use in said refractory guns.

In other words, the plastic material, if'

made of the proper consistency was too heavy or stiff to be forced through thelllmited outlet in the gun by the employmentof air under pressure, or secondary air,` blast as such pressure 1s commonly referred "to In order to overcome such resultan render the plastic mixture usable 'for' the,

refractory gun it was, therefore, necessary to intermix therewith an excess ofwaterto;

render the composition thin enough toipermit it being forced through the rrestricted outlet of the refractory gun. But-when so doing the following difhculties were created:

The excess Water materially weakened the bonding strength ofthe high temperature cement, causing it to separate and fall o'. Obviously, a patchthat will not stick is no repair at all.

jThis excess water has to be evaporated out pf the patch, which causes excessive and refractory material will not build or objectionable shrinkage developing large cracks in .the patch after the furnace has been fired.

Due to the excess water, the sprayed on ile up on the wall, much over a quarter o an inch at a time, being so wet it runs down the wall or drops off entirely, which slows up the operation, as it is necessary to wait considerable time after each application for the material to dry sufficiently to take the next coat; and it will be readily seen this is a serious objection for the time element is paramount in such work.

Restoration of furnace walls sometimes necessitates rebuilding to a depth of three or four inches, and to wait for each coat of one quarter to three eighths of an inch to dry means considerable loss of time, in addition to the time required to dry out the vast amount of excess water.

Further, the time required in emptying the gunis too long to be economical of even the labor required, not to mention the loss due to the time the plant is out of use.

Theobject of my invention is to provide a refractory gun, adapted to spray plastic material of the proper consistency without clogging or creating, air ockets within itself while it is discharging which would tend to prevent the mixture from dowing Eninterruptedly through the discharge ori- A further object of my invention is to provide a refractory gun of simple construction and which will operate in an ecient manner.

I' attain my object, in agun of the character described comprising the combination of a container provided with a head constituting a surge chamber, said head having converging walls terminating in a tubular elongate projection chamber arranged transverse of the axis of the container, the surge chamber and the projection chamber being connected by an elongate opening in combination with means for elevating the plactic material in the container into the said head, and means for applying Huid pressure to project the material from the said projection chamber. A

Further details of my invention and the construction and operation thereof are hereinafter fully described with reference to the accompanying drawings, in which? Fig. 1 shows a side elevation of my invention partly in section andillustrates the details of construction thereof.

Fig. 2 shows a longitudinal, sectional perspective View of the container and head and illustrates the proportions ofthe projection chamber. l

Fig. 3 shows a fragmentary, section of the removable headtaken longitudinally through the projection chamber and illustrates diagrammatically the movement of the plastic material and the action of the secondary airu blast. i

Figaft shows in a fragmentary, transverse section a modification in the form of the projection chamber. 3

With reference to the figures my refractory gun comprises a cylindrical container a provided with a removable hea-d b, circular at its base, but the walls converging ,up- Wardly, forming a Wedge-shaped surge chamber terminating in an elongate cylindrical projection chamber c transverse of the vertical axis of the container.

APorts are provided at each end of the said rojection chamber, forming respectively, an inlet orifice d, connected with'a fiuid pressure line e, which provides the secondary air blast, and a discharge orifice f connected to a suitable hose, g, provided at its endwith a nozzle la. through which the plastic material from the container is discharged.

A filling door z' is rovided in one of the sidewalls of Athe hea provided with offset flanges i ,in order that the said door may be seated Hush with the interior surface of the Wall and at the same time provide a fluid tight closure without obstructions on its ina pressure line Z in which are terior surface to' the movement of the material through the head.

A free moving piston j is provided in the container a and an orifice k is provided in the bottom of the container, connected with rovided shutofi valves m and n, and an Q: aust valve o',

f arranged between them, the exhaust valve serving to release the pressure under the piston and permit it to return to the bottom of the container, by gravity.

The pressure lines e and Z are connected by a T p to the main pressure line g. A shut-oil valve 1' is also provided in the pressure line c and a pressure gauge s is connected to the pressure line e on the intake side of the valve r.

In the operation of my refractory gun, the valves m, n and fr being closed and the fluid pressure shut off, the plastic, integrally mixed material isloaded into the container through the door 'i and`-`f1led up to the base of the head b, the bottom of the contamer.

piston g resting on the The container being loaded and the door z"k tightly closed and the work ready to be started, the valves m, m. and 7' are opened, the exhaust valve o bein already closed, and fluid pressure is permitted to enter the container, beneath the piston g, forcing it up- .Ward and the plastic material intothe head b, and the secondary' air blast entering the projection chamber through the orifice 0l, blows the lplastic material out through the orifice f, the hose g and nozzle It, as a spray onto the surface being coated.

When the plastic material is all discharged from the gun which will be in approximately two minutes, the valves m, n and 1 are shut off and the exhaust valve la is opened which permits the pressure in the container to escape andthe piston to return by gravity to the bottom of the container.

To repeat the operation, the container will again be filled, the exhaust valve closed, and the Valves m, n. and 1' opened and the work of lining a furnace wall with refractory material may go on.

Thus it maybe plainly seen that in the work of lining'the furnace walls of industrial plants, in which the time element is of im ortance, will be carried on rapidly and e ciently, with only the .necessary inp terruption f or filling the container. Also, by providing the head or surge chamber b of the container with converging walls and an elongate, cylindrical projection chamber, the plastic material being forced into it by the upward pressure of the 100 pistonj, will not be retarded by any 'obstruc- `tionson the said walls and further by conwhich would result in the material not being delivered through the outlet orifice continuously, causing the flow therefrom to be uneven and contain more moisture sometimes than others.

The tendency of the material to be compressed to ,too great a degree and to squeeze out some of the moisture by the compression of the material into a smaller volume is also avoided, the area of the inlet of the projection chamber being four times as great as the cone shaped head of the refractory guns of the type now in general use.

Further by providing an elongate projection chamber With an inlet orifice at ono end admitting a secondary air blast and the outlet orifice at the other, the plastic inaterial is rapidly picked up as it enters the 123 projectionl chamberand atomized and blown out the outlet orifice and through the hose, as illustrated in Fig. 3.

This action is further accelerated by forming the projection chamber nearly cylindri- 13o j walls terminating in a-tubul groesse out some of its moisture content and cause the plastic material to be too dry and stick and clog the projection chamber.

In Fig. 4 is shown a modification of the head b, in which the projection chamber 3 is not cylindrical, the side walls being parallel, thereby providing an increased area for the admission 'of the material therein, but at the same time permitting the plastic material to expand slightly in the increased cross sectional area. Y

A T 5 is provided in the connection of the pressure line to the valve m and a short pipe section 6 is connected thereto, provided with a valve 7 and acap j By this means the hose g may beremoved from the outlet orice 7 and connected to the pipe section 6, the cap 8 then being screwed over the orifice f, and a plug 9 provided in the piston j will be removed, the piston being permitted to rest onthe bottom of the container a, the container then being filled with drysan j By closing the valve ot and openingl the valves m, r and 7, the sand may be blown out through the hose g and my refractory gun used for sand blasting, which is an eiicient method of preparin wall surfaces for receiving a coating of re ractory or cementitious material'. l v

1. In a sprayer for plastic material, a container provided with a head constituting a surge chamber, said'head havingl converging are ongate projection chamber arran ed transverse of the axis of the container, t e surge chamber and the projection chamber being connected by an elongate opening, in combination. with means for elevating the plastic material in the container into the said head, and means for applying iiuid pressure tov project the materlal from the said projection chamber.

2. In a sprayer for plastic material a container provided with a head constituting a surge chamber, said head having converging walls .terminating in a tubular elongate projection chamber arranged transverse of the axis of the container, the surge chamber and the projection chamber being connected by anvelongate opening, the lcross sectional area of the projection chamber being greater than the width of said opening, in combination with meansfor elevating the plastic material in the container into the said head,

and means for applying Huid pressure to preject the material from the said projection chamber. Y

3. In a sprayer for plastic material, a container provided with a headconstituting a surge chamber, said head having converging walls terminating in a cylindrical elongate projection chamber arranged transverse'of the axis of the container,.the` surge chamber and the projection chamber being connected by an elongate opening, the diameter of the projection chamber being greater than the width of said opening, in combination with means for elevating the plastic material in the'container into the said head, and means fory applying fluid ressure to project the material from the sai projection chamber.

4. In a sprayer `for 'plastic material the combination of a container provided with a removable head constituting a surge chamber, said head having converging walls terminating in a tubular elongate chamber arranged transverse of t e axis of the container, the surge chamber and the projection chamber bemg connected by an elongate opening and a duid pressure pipe connected to` one end of said projection chamber, the opposite end of the latter being adaptedv to have a delivery pipev attached thereto.

5. In a sprayer for plastic material the combination of a container provided with a head constituting a surge chamber, said head having converging walls terminating in a tubular elongate projection chamber arranged transverse of the axis of the container, the surge chamber and the projection chamber being connected by an elongate opening and one of said converging walls provided with a door.

6. Inr` a sprayer for plastic material the combination 'of a containerA provided with a head constituting a surge chamber, .said head having converging walls terminating in a tubular elongate rojection chamber arranged transverse of t e axis of the container, the surge chamber and the projection chamber being connected by an elongate opening and one of said converging walls' provided with a door whose inner surface is gush with the interior surface of such wa 7. In a sprayer for plastic material the i combination of a container provided with a head constituting a surge chamber, said head having converging walls terminating 1 in a tubular elongate -projection chamber arranged transverse of the axis of the container, the surge chamber and the projection chamber being connected by an elongate opening, a fluid-pressure pipe connected to one end of said projection chamber, the opposite end of the glatter being adapted to have a'delivery pi e attached thereto and the cross section o the projection chamber being greater than that of said Huid pressure pipe.