In this article we will discuss about the design of core and coreless induction furnace. An improved form of core type furnace is Ajax-Wyatt vertical core type . ea1 ring induction type. CONSTRUCTION. OF FURNACE. The vertical-ring ioduction furnace makes use of the pat- sented Ajax-Wyatt heating element. VERTICAL CORE TYPE INDUCTION FURNACE Also known as AJAX-WYATT FURNACE. Vertical crucible is used for the charge. Bottom is usually V-shaped or .
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Alert me to new issues of J. My construction gives a maximum advantage for the secondary-on-secondary stirring effect already described, both through concentration of electromagnetic effect at the V due to the transformer position linking the V and because of the elimination of the counter force represented in Figure 8 by arrow 68 due to primary-on-secondary force in the prior art form.
The Ajax‐Wyatt or Vertical Ring Induction Furnace
Your email address will not be published. At the time of starting, a complete ring of metal must be present the crucible otherwise, the secondary circuit will remain open and heat will not be produced. Further purposes appear in the specification and in the claims. The current flowing through the charge is very high may be of the order of several thousand amperes.
In other words, whatever assistance primary-onsecondary pressure above the medial transformer line offers in clearing metal out ahead of the secondary-on-secondary flow is not effective until a point in the channel is reached at which the fluid resistance to upward molten metal flow along the outer channel wall has been reduced and is being progressively lowered by enlargement of the channel.
AJAX furnace – Wikipedia
Yet another disadvantage is that it requires low frequency 10 Hz supply which requires frequency changer, which involves extra cost. This causes secondary-on-secondary flow along the inner 3o channel walls at the angle directly opposing gravity return flow from the primary-on-secondary circulation.
Its efficiency is about 75 percent. A further purpose is to start primary-on-secondary stirring in the submerged channel of an electric induction furnace at the same point at which secondary-on-secondary stirring is initiated. A further undesirable feature of th3 magnetic damming action is that, due to the high temperature differential between the submerged channel and the pool, molten metal in the channel is likely to be vaporized, particularly where a high energy input into the furnace is employed.
PubMed Articles by Adam, W. In an electric induction furnace, a crucible adapted to hold a molten metal charge, walls forming a single-conduit submerged channel depending from the crucible, having two branches, each communicating with the crucible at its upper end, converging one with respect to the other branch along a straight portion and meeting the other branch at its lower end in an angle whose point is directed downwardly and a transformer core passing around and linking the angle, having its sole exciting coil between the channels and part of said core outside of but close to the angle for concentrating flux at the angle in excess of that in the channel branches close to the crucible, there being but one channel per transformer.
In an electric induction furnace, walls forming a holder for a molten metallic charge, walls forming a single-conduit submerged channel having converging branches each communicating at one end with the holder and meeting in an angle whose point is directed away from the holder at the other end, a closed magnetic circult surrounding the point of meeting ofthe branches and a transformer coil comprising the sole energizing means for the magnetic circuit.
It will be evident that both of the moving forces used primary-on-secondary and secondary-on-secondary are motor effects.
Standard sizes of these furnaces are 60 — KW, single phase 50 Hz working at volts.
Induction Heating | Ajax Wyatt Furnace – your electrical guide
For the reasons above, beneficial effect of primary-on-secondary pressure upon the molten metal above the medial transformer line is much less than the injurious effect of the counter pressure in that part of the inductiin below the medial line. The examples of direct induction heating are the high-frequency eddy current heating used for case hardening or tempering of various machine parts, annealing of steel strip and soldering.
The channel is effectively a V, whose bend is located at To overcome this difficulty, core type induction furnace is operated at a very low frequency say 10 Hz.
The stirring action is produced by the pinch effect which is proportional to the square of amp-turns.
The core is made of laminated steel and the secondary circuit is formed by the single turn of molten metal. I read your post. The induction heating may be low frequency as in the case of core type induction furnace or high frequency as the case with coreless induction furnaces. A further purpose is to concentrate flux at the bend of a submerged channel angle having the point of the angle directed away from an electric induction furnace pool.
United States Patent The power input of the vertical ring induction furnaces varies from 45 kw. Circulation is of great importance in submerged channel electric induction furnaces, not only because it is relied upon to convey heated 43 charge to the pool of molten charge, but because, without adequate and properly controlled circulation, the charge in the molten conductor will reach an abnormally high temperature at which attack upon the refractory lining of the channel will be more rapid, at which vaporization of charge in the channel may occur and at which other undesirable effects of overheating may be observed.
Pinch effect flow, due to the tendency of current in different parts of the same molten conductor to constrict the conductor and to cause ‘5 molten metal to flow upwardly along the middle of the channel has been considered in the above discussion, but has not been discussed before nor further than is herein explained for the reason that the elimination of counter-pressures along the outer walls of the channel, provided by my invention herein, is highly beneficial whether pinch effect be weak or strong.
Due to the secondary-on-secondary stirring, there is a tendency to cause molten metal to flow upwardly from the point 39 along the outside of the channel in each branch toward the pool as indicated by the arrows 64, and to permit molten metal to flow by gravity down the inside of the channel from the pool as indicated by the arrows 66, to replace the upwardly flowing molten metal. Figure 7a is a view similar to Figure 7, showing a different channel cross section.
In an electric induction furnace, a crucible, walls forming a single-conduit submerged chan- 3s nel extending laterally from the crucible, communicating at its ends with the crucible and having an angle whose point is directed away from the crucible and transformer means for concentrating flux at the angle including a core linking the channel with one leg adjacent the angle and a transformer coil within the angle which coil affords the sole energization for the transformer.
In a submerged channel electric induction furnace having a V-shaped channel with the point of the V directed from the pool of the furnace, a further purpose is to place the core of a coretype transformer around the bend of the V and to locate a coil surrounding the core between the branches of the V.
The edgepresented contour 59 of Figure 4a might also be used and somewhat less desirably the flat-presented contour 60 of Figure 4b could be employed. Google Scholar Articles by Adam, W. A further purpose is to eliminate some of the wear upon the refractory walls of the submerged channel of an electric induction furnace.
The channel is markedly diverging at its ends 40 and 41, and desirably has a groove L32 joining the two wytat at the ends. From Figure 8 it will be clear that the primaryon-secondary pressure of the prior art form having the shell type transformer tends to cause circulation directly counter to the secondary circulation in that part of the tube-constituting almost all of the funace lies below the transformer medial line and tends to cause circulation above that medial line in the same direction as the secondary-on-secondary circulation.
The essential features of Figures 5 to 7b, inclusive, are, however, the same as those of Figures 1 to 4b, inclusive. The reaction of one field upon wyattt other will 6o tend to force the molten metal charge within the channel to follow the outside of the channel in moving away from the points of high field intensity 66 which is intensified under theIron core.
Abstract The specifications for an ideal electric melting furnace are laid down, and operating data are presented to show that the vertical ring induction furnace more nearly meets these specifications than any other type of furnace. The specifications for an ideal electric melting furnace are laid down, and operating data are presented to show that the vertical ring induction furnace more nearly meets these specifications than any other type indyction furnace.
The results of the tests made upon my invention are indutcion and convince me of the commercial inductlon of the furnace of my invention; not only for wyattt of lower melting point, including brass relatively high in zinc, such as red brass, copper, but also for iron and steel.
Heat and electrical insulation of the coil have been omitted. InFigures 7, 7a and 7b, the same three channel cross sections are shown as are illustrated in Figures 4, 4a and 4b.
Ajax Wyatt Vertical Core Furnace is used for melting and refining of non-ferrous metal like brass, copper and zinc. In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such in so far as they fall within inductiion reasonable spirit and scope of my invention.
Their fields, one clockwise and the other counterclockwise about its conductor, will therefore have the same direction at some points 61 between them and wyatr inside the channel.
Please share it, your one share can change my life. From the figure, it is clear that the coupling is loose and leakage reactance is high hence the power factor is low.
Moreover, in the indirect induction heating method the eddy current are induced in the heating elements by electromagnetic induction which produces heat in heating elements. For example, in Figure 2a the angle 44′ of the V is an obtuse angle rather than an acute angle as shown in Figure 2, and any type of angle between an extremely obtuse angle and a very acute angle may be used, provided the angle point faces away from or is directed away from the pool, and does not reach or greater for reasons later explained.
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