US3616812A

US3616812A - Back-draft valve

Info

Publication number: US3616812A
Authority: US
Inventors: Joseph A Vietorisz
Original assignee: Koppers Co Inc
Current assignee: Raymond Kaiser Engineers Inc
Priority date: 1969-07-23
Filing date: 1969-07-23
Publication date: 1971-11-02
Anticipated expiration: 1988-11-02

Abstract

A BACK-DRAFT VALVE FOR USE WITH A BLAST FURNACE INCLUDES A WATER-COOLED VALVE SEAT PANEL THAT IS REMOVABLE AND REPLACEABLE AND THAT HAS A LOCKING MECHANISM TO SECURE THE VALVE SEAT IN POSITION. ALSO INCLUDED IS A FRUSTOCONICAL REFRACTORY LINING ON THE FLUID ENTRANCE PASSAGEWAY AND A CYLINDRICAL REFRACTORY LINING ON THE FLUID EXIT PASSAGEWAY OF THE VALVE HOUSING.

Description

NW. 2, 19% J. A. VIETORISZ 3,616,812

BACK-DRAFT VALVE Filed July 23, 1969 2 Sheets-Sheet 1 MGM I NVENTOR.

J05EPH A. V/ETOR/SZ cS MMM V/QUJJVL NOW, 2, 1971 vlETORlSZ 3,616,812

BACK-DRAFT VALVE Filed July 23, 1969 2 Sheets-Shoot 2 I NVENTOR.

JOSEPH A. V/ETOR/SZ mgzwm United States Patent whee 3,616,812 Patented Nov. 2., 1971 3,616,812 BACK-DRAFT VALVE Joseph A. Vietorisz, Pittsburgh, Pa., assignor to Koppers Company, Inc. Filed July 23, 1969, Ser. No. 844,136 Int. Cl. F16k 49/00 U.S. Cl. 137340 2 Claims ABSTRACT OF THE DISCLOSURE A back-draft valve for use with a blast furnace includes a water-cooled valve seat panel that is removable and replaceable and that has a locking mechanism to secure the valve seat in position. Also included is a frustoconical refractory lining on the fluid entrance passageway and a cylindrical refractory lining on the fluid exit passageway of the valve housing.

BACKGROUND OF THE INVENTION Whenever it is necessary to make repairs to or to maintain a blast furnace, such repairs being, for example, to remove and replace a worn tuyere or a blow pipe, it is necessary to divert the gases from the hearth zone of the blast furnace into a stack so that such repairs and maintenance may be carried out by workmen who will not be exposed to the high temperatures of the gases flowing from the furnace hearth.

Before undertaking such repair or maintenance work, it is necessary to make sure that all of the valves in the hot blast main leading from the hot blast stoves to the bustle pipe are closed, and that a back-draft valve in a horizontal conduit that branches off from the hot blast main or bustle pipe and that leads to the stack, is opened. Then, the gases in the hot blast main and in the hearth zone flow through the back-draft valve and into the stack.

The open back-draft valve, therefore, allows any flammable gases in the hearth zone to flow toward the stack.

These flammable gases mix with hot blast air and com bustion of the gases occurs for a short period of time in the horizontal conduit. Hence, the back-draft valve may be exposed for a short period of time to very hot flame temperatures produced by the burning gases.

The valve of the invention is capable of withstanding such very high flame temperature, and yet is readily actuated to close and open the horizontal conduit to allow the hot blast air and flammable gases to escape into the stack.

SUMMARY OF THE INVENTION A back-draft valve for use with a blast furnace includes a water-cooled valve seat panel that is removable and replaceable and that is suspended within the housing. Means cooperating with the housing and with the valve seat panel urge it into fixed cooperative relation with the housing. The fluid entrance passageway of the housing is covered internally with a frusto-conical refractory shaped lining and the fluid exit passageway in the housing is covered internally with a cylindrical shaped refractory lining.

BRIEF DESCRIPTION OF THE DRAWING The drawing illustrates one embodiment of the invention in which:

FIG. 1 is an elevational view, partly in section, of a back-draft valve in accordance with the invention;

FIG. 2 is a view along line IIII of FIG. 1;

FIG. 3 is a view along line IIIIII of FIG. 1; and

FIG. 4 is a view along line VV of FIG. 3.

DETAILED DESCRIPTION The valve 11 of FIG. 1 is a gate valve having a housing 13 and a valve bonnet 15 bolted to the housing 13. Internally, the valve 11 includes a valve disc 17 that may be similar to the valve disc disclosed in application Ser. No. 594,058, filed Nov. 14, 1966 now Pat. 3,511,262. Such valve disc is water-cooled and cooperates with a fluid cooled seat valve 33 that is disposed in the housing 13 on the downstream side of the valve disc 17. Hot gases flow through the valve 11 along a flow axis indicated by an arrow, A, of FIG. 2.

The valve housing 13, in the region of the valve opening is constructed as shown in FIG. 2. That is to say, a frusto-conical steel supporting ring 19 is secured both to a fluid entrance flange 21 on the housing 13, and to a vertical wall 23 of the fluid cooled housing 13. A triangular shaped space 25 formed by the frusto-conical supporting ring 19, the housing 13, and the flange 21 is used to convey a suitable fluid for cooling the adjacent members.

The inner surface of the frusto-conical ring member 19 is covered with a layer 27 of refractory material, and the inner surface 29 of the refractory materials is frusto-conical in shape, for a purpose that will be explained hereinafter.

The opposite side of the valve housing 13, is also provided with a frusto-conical steel supporting ring 31 that is disposed so as to form a support for a water-cooled valve seat panel 33. The supporting ring 31 is also covered with a refractory lining 35, but such refractory lining has a cylindrical internal surface 37. A triangular shaped cooling water passage 39 is also provided in the valve housing around the supporting ring 31.

In order for the back-draft valve 11 of the invention to be fully effective, it is essential that the valve seat panel 33 be locked in a central position in the housing 13. Positioning of the valve seat panel 33 in a proper central axial position is effected by means of a mechanism 40 comprising a pair of wedges 41 suitably applied to the valve seat panel 33 that cooperate with the side brackets 43 mounted to the valve seat panel, and with eccentric rollers 45 mounted on shaft 47.

It will be noted that in FIG. 1 only the valve seat locking mechanism 40 on the right hand side of the valve 11 has been shown, but it should be understood that the valve seat positioning mechanism 40 on the left hand side of the valve 11 is similar, but to an opposite hand.

A pair of stoppers 49 are welded, or otherwise suitably fixed, to a housing portion 51 that is connected to the frusto-conical supporting

rings

19, 31.

The top edge 53 of the stoppers 49, and the bottom edge 55 of the side brackets 43 are so located in relation to each other that, when the side brackets 43 coact with the stoppers 49, the horizontal center line of the valve disc 17, in the closed position, will be in the horizontal plane of the water-cooled valve seat 33. Also, the side stoppers 49 coact with the wedges 41 and position the valve disc 17 centrally in the valve housing 13 so that the vertical center line axis of the valve housing 13 will coincide with the vertical center line of the seat panel.

The eccentric roller 45 is mounted to the shaft 47 that is journaled in the housing 13 about as shown in FIG. 3, and is rotatable by means of any suitable tool applied to a protruding shaped end 57 of the shaft 47. On the protruding shaft end 57, there is a lock nut 59 that secures and holds the roller 45 in any desired position. When the roller shaft 47 is rotated, the eccentric roller 45 coacts with a curved surface 61 of the side brackets 43 to urge the valve seat panel 33 into fixed cooperative relation with the frusto-conical supporting ring 31. The surface 61 may be curved as shown, or it may be straight and a portion of a wedge, if preferred.

The interaction of the eccentric roller 45 and the curved surface 61 of the side brackets 43 prevents any upward movement of the valve seat panels 33 when the valve disc 17 is raised to its open position.

The valve seat panel 33 is cooled internally by water flowing thereinto through an inlet conduit 63, and flowing therefrom through an outlet conduit 65. The conduits 63,

65 pass through conventional glands (not shown) in the valve housing 13.

Thus, the valve seat panel 33, locked in at two sides of its horizontal center line by the mechanisms 40, can freely expand horizontally when it is exposed to heat; there being predetermined clearances between the wedges 41 and the stoppers 49. The valve seat panel 33 hangs freely downward below the stoppers 49. Only the weight of the valve seat panel and the friction in the glands, which is easily overcome, resist the thermal expansion forces acting on the heated valve seat panel 33. The valve seat panel is fork-shaped, as shown in FIG. 1 at 66, and is cooled internally. Therefore, the thermal movements will be small and the thermal forces will be well within tolerable limits.

The protruding shaped end 57 of the shaft 47 is covered with a removable cap 67 having a cylindrical part 69 that may be fitted onto the housing in which the shaft 47 is journaled.

As mentioned previously, the fluid entrance passageway in the valve housing is covered internally with a frustoconically shaped refractory lining 27. It may be noticed from FIG. 2, the inner frusto-conical surface 29 converges in the direction of the fluid flow, A, so that hot gases entering the valve 11, are directed slightly toward the center line flow axis. Thus, the hot gases are directed away from the sealing face of the fluid cooled valve seat panel.

Although, the locking and centering positioning mechanism 40, as well as the frusto-conical shaped lining are described herein with reference to a back-draft valve, it is understood that the present invention is not limited to only a back-draft valve, and it may be applicable to any valve of the gate type.

From the foregoing description of an embodiment of the invention, those skilled in the art will recognize several significant features and advantages, among which are:

That the valve seat panel is effectively centered and securely locked in the valve housing in a simple manner;

That the locking device is readily and easily serviceable from outside of the valve housing;

That the valve seat panel is not subjected to excessive stresses due to thermal expansion; and

That the internal refractory lining covering the fluid inlet flow passageway is frusto-conical to direct the hot gases flowing through the valve away from the sealing face of the valve seat panel.

What is claimed is:

1. In a gate valve having a housing with entrance and exit passageways and a valve disc moveable therein to regulate the flow of fluid along an axis through said gate valve, the improvement comprising:

(a) a fluid cooled valve seat panel disposed in said housing;

(b) a pair of spaced apart stoppers mounted to said housing;

(c) a pair of spaced apart brackets that are mounted to said valve seat panel and that are cooperative with respective stoppers;

(d) a pair of diametrically opposed wedges mounted to said valve seat panel that cooperate with said stoppers to center said valve seat panel in said hous- 111g;

(e) a pair of spaced apart side brackets that are mounted to said valve seat panel, and that have one surface that is cooperative with (f) an eccentrically mounted roller fixed to a shaft journaled in said housing with;

(g) means for rotating said shaft and roller to urge said valve seat panel towards and into cooperative fixed relation with said housing;

(h) a refractory lining on the internal surface of the entrance passageway of said valve, said lining having a frusto-conical internal surface converging in the direction of fluid flow through said valve; and

(i) refractory lining on the internal surface of the exit passageway of said valve, said lining having an internal cylindrical surface that is coaxial with the fluid flow axis through said valve.

2. In a gate valve having a housing with "both an entrance and an exit passageway and having a valve disc movable therein to regulate the flow of fluid along an axis through said valve, the improvement comprising:

(a) a fluid-cooled valve seat panel disposed in said housing;

(b) means on said seat panel coacting with fixed means on said housing for supporting said seat panel in a central axially aligned position in said housing;

(0) a pair of spaced apart side brackets mounted onto said valve seat panel with one surface of each bracket cooperating with (d) an eccentrically mounted roller fixed to a shaft journaled in said housing;

(e) means for rotating said shaft and roller to urge said valve seat panel towards and into cooperation with said housing; and

(f) refractory lining disposed over the interior surfaces of both the entrance and the exit passageways of said valve housing.

References Cited UNITED STATES PATENTS 3,040,773 6/ 1962 McInerney 137-340 X 3,068,888 12/1962 Mohr, Jr. 251-158 X 3,126,941 3/1964 Mohr et al. 137340 X 3,171,429 3/1965 Sturrner et al 251-159 X 3,207,174 9/1965 Berczynski 137340 X 3,266,517 8/1966 Carr 137340 3,430,689 3/1969 Pantke et a1 137340 X SAMUEL SCOTT, Primary Examiner