• Mecanique De Fluide

E225 - Principes generaux de l'etat d'equilibre des fluides (General principles concerning the state of the equilibrium of fluids) Summary: (based on Clifford A. Truesdell's introduction to Opera Omnia Series II, Volume 12) This work, the first of a series of three that constitute Euler's masterful treatise on fluid mechanics (the others being E226 and E227), contains a formulation of. Mini Manuel De Mecanique Des Fluides 2e Edition Rappels De Cours Exercices Corriges 07 Aug 2019 - Download this most popular ebook and read the Mini Manuel De Mecanique Des Fluides 2e Edition Rappels De Cours Exercices Corriges ebook. You'll not find this ebook anywhere online.

April 12, 1955 B. MILLGARD DEVICE FOR PRESSING OUT A FLUID FROM A MATERIAL IN PIECES Filed May 51 1951 United States Patent DEVICE FGR PRESSING OUT A FLUID FROM A MATERIAL IN PIECES Bror Manne Millgard, Ljusne, Sweden Application May 31, 1951, Serial No. 229,115 1 Claim. 100-95) irrespective of whether amount of material present is less than the maximum capacity of the pressing device. Another object of the invention is to construct a device capable of pressing the material for whatever length of time may be necessary for the complete outflow of the water, pressed out.

Another object of the invention is the provision of a device, which permits a sutficiently high pressing force without any possibility for the material to be jammed in the device causing a break down or damage of the machine. A device according to the invention is provided with a primary and a secondary reciprocating press member registering with each other, said press members being forced one against the other with the same or substantialy the same pressure. The invention is characterized by the fact, that when the pressure acting on said secondary press member has reached a predetermined value, said pressure is maintained substantially constant so that a further increase of the pressure acting on the primary press member, displaces said primary press member together with the pressed material and the secondary press member thereby during maintenance of the press intensity displacing said material in the moving direction of said primary member to a position for removing of a greater or lesser quantity of the pressed material. One embodiment of the invention is schematically shown in the accompanying drawing, partially in section.

The embodiment shown in the drawing is assumed to be connected to a hydraulic pressure system. To the opposite ends of a hydraulic cylinder 1 with a piston 2, conduits 3, 4 are leading from a slide valve 5. This slide valve controls the communication between said conduits 3, 4 and a feed line 6 for pressure medium on one hand and two outlets 7 and 8 on the other hand. The piston 2 is fixed to a tubular piston rod 9, the outer end of which is shaped like a press head 10, forming the primary press member, said piston 2 being slidable in a press chamber comprising two sections 11a, 11b.

Section 1111 is situated nearest the cylinder 1 and has a filler opening 12 for the material to be pressed. The other section 11b of the pressing chamber has a cylinder shape so that the press-head of the tubular piston-rod 9 fits therein as a piston. Both the circumference wall of the section 11b and the end wall of the press-head 10 are perforated, said tubular rod having in its inner end a drainage opening 13 for the water. The outer end of the cylinder 11b is covered by a movable counterpress plate 14, said plate also being perforated at 14'. The counterpress plate 14 forming the secondary pressmember is the outer end wall of a hollow piston rod 7 15 for a piston 16 in a hydraulic cylinder 17. For draining the liquid entered into the hollow piston rod 15 an aperture 15' is provided in its circumferential wall at the lowermost point thereof near the end wall 14.

Opposite ends of the cylinder 17 are connected to conduits 18, 19 connected to a slide valve 20 through conduits 22, 21 and 24, respectively. The conduit 19 permanently communicates with the conduit 4 via a conduit 23. The housing of the valve 20 communicates with the conduit 3 through a conduit 25, said conduit 25 in turn being leading via a ice conduit 26 to the upper end of said valve housing. Against the lower end of the valve 20 abuts a compression spring 27. A knife 28 is mounted for transverse reciprocation at 32, 33 leading to opposite ends of the cylinder 30, an inlet 34 for the pressure medium and two discharge conduits 35, 36. The valves 5 and 31 are operated by solenoids 37 and 38 respectively, and the valve 20 is operated in one direc' tion by the hydraulicpressure from the conduit 26 and; in the other direction by the spring 27.

The solenoid 37 is controlled by a timing relay 39, said relay 39 being coupled in a circuit 40 between the solenoid 37 and a contact member 41, said contact mam'- ber being arranged in the path of warm 42 attached to the tube 9. The circuit of the solenoid 37 comprises a conductor 43 to a contact member 44 arranged in the path of an arm 45 attached to the knife 28. The circuit of the solenoid 38 comprises a conductor 46 to a contact member 47, adapted to be operated by the arm 42 and also a conductor 48 to a contact member 49 arranged in the path of the arm 45. In the following the operation of the valves will be more clearly described in combination with the descrip tion of the manner of working of the machine. In the drawing the machine is shown in a position at which the piston 2 is moved to its right end position.

Consequently, the tubular piston rod 9 and the press-head 10 are moved to their end-positions. The counterpress plate 14, which is normally pressed against the mouth of the cylinder 11b of the press chamberis moved a small distance away from the mouth of the cylinder by the material 50, which has been packed in said cylinder 11b as described in the following. At the beginning of the pressing operation the piston 2 was situated in its left end position in the cylinder 1 and the press head 10 of the piston rod 9 had reached the left end wall of the filler opening 12. Thereafter, the valve 5 takes the position shown in the drawing, thereby supplying pressure medium to the left end of the cylinder 1 comprising the piston 2 via the pipe 3. The valve 20 also takes its shown position so that the pressure medium from the pipe 3 is supplied to the right end of the piston 16.

At the first pressing step the counterpress plate 14 is pressed by the same force as the press head 10 against the material packed in the cylinder 11b. In order to permit the packed material to be forced forward through the cylinder 11b the pressure in the counterpress cylinder 17 must be prevented from exceeding a certain limit of pressure, said limitation being afforded by the valve 20. This valve is actuated in one direction by the pressure in the conduit system 3, 25, 26 and in the other direction by the spring 27, said spring being dimensioned to be compressed when the pressure on the upper end of the valve has reached a certain value.

Then the valve 20 is forced downward whereby it closes the supply of pressure medium from the pipe 25 to the right end of the counterpress cylinder 17. At the same time a communication is attained from the conduit 18 via the conduits 22, 24 with the conduit 23, said conduit 23 being in communication with the outlet 8 in the position shown in the drawing. At this time, both sides of the piston 16 are in communication with said outlet 8. When the pressure in the press cylinder 1 increases above the pressure in the cylinder 17 limited by the spring 27, the press head 10 will displace the packed material 50 in the cylinder 11b, thereby moving the connterpress piate 14 to the right, causing a portion of the material to be fed out of the cylinder 11b, as is shown at 51. When the press head 10 has reached its outer end position (to the right in the drawing) the arm 42 attached to the piston-rod 9 operates the contact member 41, said member energizing the timing relay 39. This relay 39 is adjustable in order to permit the press head 10 to exert a force on the material during a neces- Patented Apr. 12, 1955 sary period.

Mecanique De Fluide

When this period is finished, the timing relay energizes the solenoid 37, said solenoid operating the valve 5, so that the pressure in the cylinders 1 and 17 is reversed, whereby the pistons 2 and 16, respectively, are moved back to their initial. When-the piston 2 has reached its left end position, the arm 42 operates the contact 47, said contact thereby energizing the solenoid 38. Said solenoid-operates the valve 31 causing the piston 29 tomove the knife 28 downwards in order to cut off the portion 51 of the material inthe formof a briquette to be removed. When the knife has reached its lower end position, the arm 45 operates the contact 49 in order to disconnect the solenoid 28 and, consequently, the valve 31 is operated.

And the knife is moved back to its initial position. In this position the arm 45 operates the contact 44, which disconnects the solenoid 37, thereby causing thecounterpress piston 16 to move forward for pressing the material, which in the meantime has been supplied through the feed opening 12., During the pressing of this material the water is pressed out and drains off through the openings in the cylinder 11b, the press head 10 and the counterpress plate 14. Owing to the drainage of water in all directions the pressing device according to my invention secures a good drying effect. The drying effect is improved by the fact that the material to be severed at the end of the pressing operation is entirely fed out of the cylinder 11b.

The period necessary for drainage of the water is easily regulated by the'timing relay 39. The cylindrical section 11b of the press chamber can be made so long that the same amount of material can be subjected to several repeated pressing operations before the final feeding out. The mouth of the press chamber can be formed for the purpose of the best drainage effect. As the press head does not move throughout the whole length of the press chamber theouterend portion of the cylinder 11b can be provided with a decreasing or increasing area towards the mouth or it can be entirely cylindrical, depending on the properties of the material to be pressed. This may not be permitted in presses, by which the press member is moved throughout the entire length of the press chamber.The press head 10 should be constructed in such a w-ay'as to secure a uniform distribution of the material throughout the whole cross section of the cylinder 11b.

Especially with a horizontal arrangement of the pressing device the material will collect at the bottom of the press chamber, if at each piston stroke the material does not fill up the pressing chamber completely. At incomplete filling up of the press chamber the material to be pressed must be given an upwards directed movement, said movement being obtained by use of an oblique or a concave pressing surface, as shown in the drawing. For the purpose of cutting oif the portion of the material extending above the path of the piston rod 9 in the filler opening the press head is provided with an annular knife 52 cooperating with a ring 53 of similar material. At the outer end of the press chamber the knife 28 is arranged to slide against a ring 54 of knife steel, fixed at the mouth of said end. Patent Citations Cited Patent Filing date Publication date Applicant Title.

Feb 6, 1911 Sep 26, 1911 Joseph Stehlin Hydraulic press. Dec 2, 1932 Jun 22, 1937 Nat Automatic Tool Co Timing relay for machine tools. May 4, 1940 Feb 23, 1943 Lee Harry S Method and apparatus for handling and dispensing food products. Jul 20, 1944 Jun 24, 1947 Habenicht August F Pressing apparatus. Jul 26, 1928 Jan 16, 1931 Hermann Zander Selbsttaetige hydraulische OElpresse mit Kolben und Gegenkolben. Title not available. Title not available.