US2873492A

US2873492A - Hot tops, feeders or sinking head boxes

Info

Publication number: US2873492A
Application number: US605346A
Authority: US
Inventors: Vallak Enn
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-08-21
Filing date: 1956-08-21
Publication date: 1959-02-17
Anticipated expiration: 1976-02-17

Description

Feb. 17, 1959 E. VALLAK 2,873,492 nor TOPS, FEEDERS OR smxmc HEAD BOXES Filed Aug. 21, 1956 Fig. 1

INVENTOR: ENN VALLAK/ United States Patent nor rors, FEEDERS 0R SINKING HEAD BOXES Enn Vallak, Geneva, Switzerland Application August 21, 1956,Serial No. 605,346

1 Claim. c1. 22-147 This invention relates to so called hot tops, feeders or sinking head boxes. Such hot tops are employed in casting molds, particularly ingot molds, in order to prevent the so called pipe from arising in the ingot. To this effect it has been proposed to make hot tops of heat insulating, ceramic material, but hot tops of wood and other combustible material are also known in the art, whereby the combustion heat is utilized as to prevent the top section of the ingot from cooling down too rapidly. A particularly useful and suitable hot top design is described in the Swedish Patent No. 142,209, corresponding to my co-pending U. S. patent application Serial No. 351,546, filed April 28, 1953, which became abandoned on April 26, 1957, according to which the hot top consists of a combustible material, which at the same time is porous, i. e. pervious to gases.

When such combustible hot tops are employed, it is of the utmost importance that the air necessary for the combustion may quickly enter the inner portions of the hot top material, enabling the combustion to proceed with the desired speed and uniformity.

The main object of my present invention is to effect this task by providing the combustible or possibly exothermic hot top material with inner ducts or recesses, communicating at least at one end with the atmosphere and permitting an air stream to be supplied to and through the inner portions of the hot top. In order to maintain a constant circulation of air, it is suitable to provide at least two ducts or recesses, separated by an intermediate wall; one or more of said ducts or recesses serving for the supply of fresh air and the other for disposing of flue gases.

An embodiment of the device according to the invention is shown diagrammatically on the accompanying drawing, in which:

Figure 1 is a perspective view of a hot top plate seen from the inside;

Figure 2 is a fragmentary vertical sectional view of a portion of an ingot mold wall with a hot top plate of the type shown in Fig. 1 attached thereto.

The hot top plate is designated with 1 on the drawing and consists of combustible material, such as pulverized coke, coal or charcoal, saw dust or the like, which together with a binding agent, such as waste sulphite lye, is formed into plates of desired shape and in such a manner that the plates will become porous, namely pervious to gases so that, in burning the plate, the flue gases may escape through the walls of the hot top material without trying to find their way out through the molten metal in the ingot mold 5. According to the embodiment shown, the hot top plate 1 is provided with two recesses or ducts 2, separated by an intermediate wall 3. At the top these recesses 2 communicate with the atmosphere, and at the bottom they communicate with each other through a passage or opening 4. When the hot top is burning, affected by the heat from the molten metal of the ingot mold. 5, fresh com bustion air is supplied to one recess 2, as indicated by the arrow to the left of Fig. l, and this air will enter the other recess 2 through the opening 4, whereupon excess air and flue gases escape at the top of the last mentioned recess, as shown by the arrow to the right of Fig. 1. Thus, inside the hot top a circulation of air is maintained, causing the combustion to occur faster and more uniformly.

The recesses 2 are preferably disposed on the side of the hot top facing the ingot mold wall 5. As a matter of course, nothing prevents two or more ducts or recesses from being arranged in each plate, but it is essential that intermediate walls 3 are arranged in order to obtain a guided air stream through the plate.

The ducts may take the form of a number of separate more or less vertical channels within the material of the plate, said channels communicating With the atmosphere at least at one end and preferably at both ends, so as to admit air to enter at one end and flue gases to escape at the other end.

The composition of the plate may vary from case to case but in many cases I prefer to utilize the composition described in my pending U. S. application Serial No. 351,546.

What I claim is:

A hot top plate, for use in connection with an ingot mold having an encircling wall, said plate including combustible material and being adapted to be disposed adjacent the internal surface of said wall, said plate including two side flanges and a bottom flange connected therebetween, and an upright ridge between said side flanges extending from the top of said plate to a point spaced from said bottom flange for a certain distance, said plate with its flanges and ridge being adapted to define with said internal wall surface an upright U- shaped air channel having two upright branches and a connecting branch therebetween, said certain distance being inferior to the distance between said ridge and either side flange whereby the connecting branch will have a smaller cross section than the upright branches, both upright branches being open on top.

References Cited in the file of this patent UNITED STATES PATENTS 1,139,284 Hitt May 11, 1915 1,208,703 Turner et al. Dec. 12, 1916 1,235,744 Washburn Aug. 7, 1917 1,258,209 Gathrnann Mar. 5, 1918 1,500,759 Howard et al. July 8, 1924 FOREIGN PATENTS 519,349 Canada Dec. 13, 1955 1,084,725 France July 13, 1954