HYDRAULIC FILTERING PRESS FOR TREATING OLEAGINOUS SEEDS.
Messrs. Laurent Bros. & Collot exhibited at the Paris Universal Exhibition in 1878 a patented hydraulic apparatus styled a filtering press, the principle and construction of which it will prove of interest to describe. The apparatus is remarkable for its simplicity and ease of manipulation, and is destined to find an application in most oil mills.
Details of Structure.--The filter, which is shown in detail in Figs. 5 to 7, is formed of two semicylindrical cast iron shells, F, that are firmly united, and held by a strong iron band which is cleft at one point in its circumference, and to which there is adapted a mechanism permitting of loosening it slightly so as to facilitate the escape of the oil-cake. Within these shells, F, there are grooves, a, which have the arrangement shown by the partial section in Fig. 11, and through which flows the oil expressed by pressure. To prevent the escape of the material through these grooves or channels, the interior of the shells is lined throughout with plates or strips of brass that fit very closely together, and present a simple slit with chamfered edges opposite the grooves. At the two joints of the shells four of these plates are riveted two by two; all the others are movable, and rest, like the pieces of an arch, against the fixed plates that form abutments. Each half lining is thus held by means of a central plate, b' (Fig. 10), with oblique edges, and which, being driven home by the top of the filter, binds the whole tightly together. All these plates, which are slightly notched at their upper part, rest on a small flange at the lower part of the shells.
FILTERING PRESS FOR OLEAGINOUS SEEDS.--AUTOMATIC INJECTION PUMP
As regards their manufacture, these plates are cut out of sheets of perfectly laminated brass, and are afterward set into a matrix to center them properly. After the shells have been bored out, all the plates are mounted therein so as to obtain a perfectly cylindrical and uniform surface. The plates are then numbered and taken out; and, finally, a slit with chamfered edges is cut longitudinally through them, save at three points--two at the extremities and one at the middle. The plates thereafter rest against each other only at these three points, and leave at the chamfered places capillary openings just sufficient to give passage to the oil, but not to the pressed paste, however fine it be. As will be seen in Fig. 5, the points of contact are not in the same horizontal plane, but are arranged spirally, so that the flow will not be stopped at this place as it would be were these solid parts all at the same height. The filter, F, is completed by two pieces that play an important part. The first of these is a cast iron rim, J, which is set into the upper edge, and forms a sort of lip whose internal diameter corresponds exactly to the surface of the plates, b. This rim, J, is cast in one piece, and carries on its circumference two small, diametrically opposite iron studs, which are so placed that they may engage in the groove, p, at the upper edge of the shells, F.
The second of the two pieces is a cast iron bottom, K, which works on a hinge-joint, and which is perforated with a large number of holes for giving passage to the oil that has traversed the hair cloth cushion of which we shall speak further on. These holes must correspond accurately with the radial conduits presented by plate, E, and through which flows the oil to a circular channel running around this same piece. In order to exactly maintain such a relation between the holes and channels, the piece, E, is provided with a stirrup-iron, d, that passes around one of the columns, C, of the hydraulic press.
The entire filter thus constructed is attached to one of the columns, C', of the hydraulic press in such a way that it can revolve around it. For this purpose, the column is surrounded by an iron sleeve, L, cast in two pieces, and which in its lower position rests on the shoulder, e, of the column. The filter is connected with the sleeve by means of screws, as shown in Fig. 6.
We shall now describe the mechanism for loosening the band, I, and moving the bottom, K.
The band, I (Figs. 5 to 9), is cleft at a point in its circumference corresponding to one of the joints of the shell, F, and carries at each side of the cleft a bearing in which turns freely a steel pin. One of these latter, i, is cylindrical, and the other, j, has eccentric extremities that are connected with the former by two small iron rods, k and l. The upper extremity of the pin, j, is provided with a bent lever-handle, M, and the lower one carries in its turn a small disk, m, the use of which will be explained further on. It results from such an arrangement that by acting on the lever, M, with the band, and by reason of the eccentricity of the pin, j, the two extremities of the band, I, may be made to approach or recede at the will of the operator. The position of nearest approximation is limited by the abutting of the hook at the end of the lever, M, against the side of the filter. This latter position corresponds to the moment of charging the apparatus (Fig. 6), while the contrary one indicates the moment that the oil cake falls (Fig. 4). Although the separation is but a few millimeters, it is sufficient for disengaging and allowing the cake to drop.
The movable bottom, K (Figs. 5 and 6), which closes the base of the filter during the pressing, becomes detached and drops vertically (Figs. 3 and 4), when the filter is disengaged from the press, and the oil cake is to be dropped out. To render the maneuver of this part easy, the bottom is provided with a projecting piece, N, united by a bolt with the band, I, and furnished with an articulated hand-lever, N', that terminates in an appendage, q. The upper part of the hinge is provided with a tail piece, q', under which the appendage q, places itself when the bottom, K, is brought to its horizontal position. Consequently, when the operator desires to let the bottom drop in the position shown by the dotted line (Fig. 5), after the filter has been loosened, he moves the lever, N, to the position shown by the dotted line (Fig. 6). The appendage, q, then disengages itself from the tail piece, q', and the bottom is thus enabled to assume a vertical position. As the bottom at the time of charging would not be sufficiently supported if there merely existed the lever and catch, it is further provided at its opposite extremity with an appendage, r, which slides over a catch, r'. This latter is attached to the disk, m, at the lower extremity of the pin, j (Fig. 7), and takes exactly the proper position when the band is closed at the moment of charging, but leaves it, on the contrary, when the band is loosened to allow the oil cake to drop out.
As the lateral flow takes place through the interstices of the brass lining, there is need of but one cushion on the bottom and another at the top to hold the material to be pressed. The first is a simple hair-cloth disk for preventing the seed from passing through the perforations in the bottom plate; and the second, O, of which Figs. 12 and 13 represent a segment, is formed of three thicknesses of the same material united at the edges by two flat iron circles, s, riveted together. These circles, which are made to fit the inside diameter of the shells very accurately, prevent any leakage of the oil around the presser, G, and keep the hairs from getting caught between this piece and the plates, b.
Charging of the Filter. (Figs. 14 and 15.)--The apparatus for charging the filter is of the same capacity as the latter, and is made of galvanized iron. It is placed on a slide at the aperture of the steam kettle so as to receive the warm seed as it is thrown out by the stirrer. When full, it is taken up by its handles, rested on the rim of the filter, and its contents emptied therein.
General Manipulation of the Press.--Supposing the filter in the position shown in Figs. 3 and 4, at the moment the seedcake is about to drop out: the operator takes hold of the lock lever, N, with his left hand, raises the bottom, K, to a horizontal position, and at the same time fastens the bolt of the lever by turning it. He then seizes the lever, M, with his right hand, and turns it so as to close the filter, having care at the same time to support the extremity, r, of the bottom with his left hand so that the catch, r', may pass under it when the lever is manipulated. The bottom haircloth is then put in place, the charge is thrown in, and its surface leveled, and the hair-cloth cushion is laid on top. The filter is then revolved around the column so as to bring it into the position shown in Fig. 1. The cock of the distributer that admits water under pressure being turned on, the ram, D, rises, carries with it the filter, and compresses the material against the presser, G. At the end of from six to ten minutes the pressure-valve is closed and the discharge-valve opened. The filter then slides down with its socket along the column, C', till it reaches the shoulder, e, where it rests. It is next swung around to the position shown in Fig. 3, and emptied of its contents by a manipulation, the reverse of that described for charging it. All these manipulations of charging and emptying require no more than half a minute on the part of an experienced workman.
The press under consideration is well adapted to the treatment of heated seed paste, and has been very successfully employed for that purpose in France, Belgium, and Holland. It succeeds equally well for the extraction of oil from nuts. Referring to the drawings, the scales are for Figures 1, 2, 3, 4, 14, 15, one fifteenth actual size; Figures 5, 6, 7, 8, 9, one-tenth; Figures 10, 11, 12, and 13, one-fifth.--Machines, Outils et Appareils.
LAURENT & COLLOT'S AUTOMATIC INJECTION PUMP.
As well known, in every well-constructed injection pump, there is a system of gearing which acts upon the suction valve and stops the operation of the pump as soon as the requisite pressure is reached; but the piston, for all that, continues its motion, and, besides the resistant work of the pump has passed through different degrees of intensity, seeing that at every moment of its operation the piston has preserved the same stroke and velocity. We are speaking, be it understood, of pumps that are controlled mechanically. In the one that we are about to describe, things take place far otherwise. In measure as the pressure increases, the stroke of the piston diminishes, and when it has reached its maximum, the motion of the piston ceases entirely. If, during the operation progression undergoes more or less variation, that is, for example, if it diminishes at a given moment to afterwards increase, the stroke of the piston undergoes all the influences of it.
The pump of which we speak is shown in Figs. 16 to 21, and is the invention of Messrs. Laurent Bros. & Collot. It may be described briefly as follows:
The apparatus, as a whole, has for base a cast-iron reservoir; A, to the top of which is fixed the pump properly so-called, B, as well as the clack box, A, and safety valve. The pump is placed opposite an upright, D, whose top serves as a guide to the prolongation, E, of the piston rod. This latter is traversed by a pivot, a (Fig 19), on which is mounted a lever, F, whose outer extremity is articulated with a connecting rod, G, which is itself connected with the cranked shaft, G¹. This shaft has for its bearings two supports, b, attached to the reservoir, and carries the driving pulleys and a fly wheel. The beam, F, having to give motion to the piston in describing an arc of a circle at the extremity attached to the connecting rod, must, for that reason, have a fixed point of oscillation, or one that we must consider as such for the instant. Now, such point is selected on a piece, H, having the shape of the letter C, and which plays an important part in the working of the pump. This piece is really a two-armed lever, having its center of oscillation in two brackets, c, at the base of the reservoir. Fig. 17 shows the relation of the beam, F, and lever, H. The upper extremity of this latter is forked, and embraces the beam, F, whose external surfaces are provided with two slots, d, in which to move slides, e, attached to studs, f, which are perfectly stationary on the extremities of the forks of the lever, H. One of the slots is shown in section on the line 1--2 in Fig. 20, and on the line 3--4 in Fig. 21.
Things thus arranged, if we suppose the piece, H, absolutely stationary, it is clear that, as the oscillation of the beam, F, is effected on the studs, f, as centers, the piston of the pump will perform an invariable travel whose extent will be dependent upon its position between such point of oscillation and the point of articulation of the connecting rod, G. But we must observe that even according to such a hypothesis, the point, f, would not be entirely stationary, because the point of articulation, a, upon the piston rod being obliged to follow an invariably straight line, the slots, d, will have to undergo an alternate sliding motion on the slides, e, save, be it understood, when the latter are brought to coincide exactly with the center of articulation, a. Now we shall, in fact, see that the point, f, can move forward in following the slots, d, and that it may even reach the point of articulation, a, of the beam, F, on the rod, E, that is to say, occupy the position shown in Fig. 18, where the oscillation of the beam, F, being effected according to the point, a, the stroke of the piston has become absolutely null.
The position of the piece, H, is, in effect, variable with the pressures that are manifested in the pump. It will be seen that the latter has a tubular appendage, g, in whose interior there plays what is called a "starting rod," h, which is constantly submitted to the pressures existing in the interior of the pump, and which rests against the lower arm, H¹, of the piece, H. But this latter is also loaded at the opposite side with heavy counterpoises, i, which counterbalance, within a determinate limit, the action of the rod, h, that tends constantly to cause the lever, H, to oscillate around its pivot, in the brackets, c.
To sum up, then, as long as the pressure in the pump has not reached a determinate limit, the lever, H, held by its counterpoises, i, will keep the position shown in Fig. 16, and for which the center of oscillation, f, corresponds with the maximum stroke of the pump piston. But as soon as such limit is exceeded, the equilibrium being broken, the action of the rod, h, predominates, the piece, H, reverses from right to left, the point of oscillation, f, moves forward in the slots, d, and the stroke of the piston is reduced just so much. If, finally, the pressure continues to increase, the motion of the piece, H, will continue, and the point of oscillation, f, will reach the position for which the motion of the piston ceases completely (Fig. 18).
But it results further, therefrom, that if when such position is reached, the pressure diminishes, the lever, H, will, under the influence of its counterpoise, tend to return to its first position and thus set the piston in motion. As we remarked in the beginning, the automatism of these functions is absolutely complete.
It will be remarked that the piece, H, is provided with an appendage, H², whose interior forms a rack. This rack engages with a pinion, I, mounted on an axle, J, which carries externally a fly wheel, K. This axle, J, moves with the various displacements of the lever, and its fly wheel overcomes by its inertia all backward and forward shocks resulting from the thrusts due to the sliding of the steel slides in the different positions of the connecting rods. Such shocks would make themselves especially felt while the dead centers were being passed.
The velocity with which this pump runs varies from 75 to 80 revolutions per minute. It easily gives a pressure of 200 atmospheres. With a hydraulic press having a piston O.27 of a meter in diameter, it permits of effecting in ten minutes the extraction of the oil from 25 kilogrammes of colza seeds. Referring to the drawings, the scales for Figures 16, 17, 18 are one-fifteenth actual size, and Figures 19, 20, 21, one-tenth.--Machines, Outils et Appareils.