EP2335914A2 - Piston press - Google Patents

Abstract

The press is designed such that thin sheet screen plates are inserted into four upright, lateral openings in a quadratic- square tube frame in such a manner that vertical edges of sheets form a seamless angle. The sheets are completely supported from behind with grids. The plates are screwed onto the grids while the grids are screwed to an inner frame surface such that upper and lower openings of a designed cage retain a screen structure, where the screen structure is externally mounted in a vertical, reversibly movable manner by a respective hydraulic cylinder.

Description

Description.

The invention relates to a piston press with a cage for muddy liquids. It relates primarily to devices for filtering manure.

The disadvantage of these techniques is a high residual moisture in the expressed dry matter, as well as the susceptibility to failure. Mostly used round cylindrical sieves are thick walls because of the statics and must be perforated with water jet, lasers or drills. That makes them expensive. The use of slotted screens is even more costly. As most of the stables are being rinsed today, stones, sand or even objects enter the machines again and again. In particular, the expensive slotted screens often suffer damage.

The European patent "High pressure vessel with stamping device" EP 0260 249 A1 and the DE 696 13 699 T2 describe a piston press in a closed round cylinder with two counter-rotating plunger, by two vertically, in opposite directions moving pistons with attached seven presses.

In our own experiments with such a design and a pressure up to 200 bar in the hydraulic cylinders and a diameter of 80 cm, 100 cm in length, and 0.8 mm sieve holes, it was impossible with this system even 300 liters in one operation to squeeze because both filters clogged prematurely.

Task of this invention is therefore to have larger screen areas and still be able to press with a high piston pressure. Not only the screens, but the entire construction should be cheap and the user should be able to replace all stressed parts easily and quickly, without having to consult specialists. In addition, the screens should be automatically cleaned at each press.

The solution is carried out by a reciprocating press, according to claim 1. The piston press according to the invention has a rectangular, preferably square shape, wherein four lateral screen plates are mounted in the base frame, which are supported by commercial gratings.

By this arrangement, it is possible to use in a reciprocating press on the four sides and the piston plates punched screen plates of only one millimeter thickness, which are still individually, easily replaceable. In many experiments, a combination of a millimeter thin screen plate and a grid was developed as a support, which are simply bolted together. The lateral sieve arrangements are mounted in the lateral open fields of a square tube frame. The four screens are advanced until the vertical edges of the adjacent screens form a right angle. A corresponding statics of the gratings allows a hydraulic piston pressure up to 200 bar.

Expensive, thick-walled screens made with laser or water jet technology with surfaces with small tolerances are also unnecessary, as thick Stahlstützrohe or plates. Supporting the fine sheet metal screens with gratings also led to more passage of the filtrate. The plunger plates have the same sieve construction.

Instead of piston rings as a seal or scraper, a piston seal made of silicone rubber was generated, which can be selectively leveled. It is wear-resistant, cleans the sieves at each stroke, easily replaceable and, moreover, considerably less expensive than piston rings. The gasket is sandwiched between a circumferential square bar bolted to the frame of the piston plate and a same, congruently located below, which is bolted to the overlying seal.

By tightening or loosening individual screws, the seal exits at this point or retracts. It can be selectively leveled and adapted to intolerances, whereby the contact pressure on the side walls can be flexibly adjusted.

In this way, we have a screen cage open at the top and bottom, in which the top and bottom can both be moved up and down hydraulically. With an edge length of the cage of one meter, a screen area of almost six square meters is created, with a volume of approx. 0.8 cubic meters per filling. The filtrate is collected in a casing of the cage and removed.

Preferably, first pressed from bottom to top and then the floor is returned to the starting position. This creates a turbulence of the sediment, which makes the bottom sieve again durchgängiger. The ejection of the sediment is carried out in the entire width of one side of the cage by a slide which is guided on the bottom sieve and pushes the dry matter through a flap in the opposite side. In order to prevent overflowing of the sediment via the slide, the upper press bottom moves down to the slide, so that it forms a closed drawer with the lower one.

Before ejecting the upper piston plate is shut down until it shuts off at a pre-defined pressure from about 150 bar. Since the bottom sieve and the side screens can be almost impermeable in dense heights, then opens the ejector a small gap and the slider is also withdrawn until it also opens a gap. In this way, not only any remaining raw slurry that is above the sludge and is no longer to be pressed through the sieves, pressed again into the input circuit, but also the extreme pressing of the filter cake lying on the ground possible. In tests, a residual moisture content of only 10% was achieved.

This new technology also makes it possible for the first time to squeeze out pig, cattle or poultry manure with one and the same machine, without special prior adjustment or retrofitting.

Claims (7)

Piston press with a cage, wherein the cage is formed from a rectangular, preferably square square tube frame and in the four upstanding, lateral openings Feinblechsiebplatten are introduced such that the vertical edges of the screen plates form seamless angles, the screen plates over the entire surface from behind Gratings are supported on which the screen plates are screwed, wherein the gratings are screwed to the inner frame surface and wherein in the lower and upper opening of the cage depending a piston plate (b, c) is provided, the outside by a respective lifting cylinder, vertical, are mounted movable in opposite directions and each consist of the same sieve construction of the cage. Piston press according to claim 1, characterized in that angular support frame as the piston plates (b + c) vertically movable gratings have a circumferential square seal preferably made of silicone rubber, which is clamped between a rigid and a congruent screwed to this frame such that by tightening or loosening individual Screws the tension of the seal is selectively leveled. Piston press according to claim 1 or 2, characterized in that above the bottom sieve (b), in its basic position, two opposite, vertical sieve sides are designed so that one side has an outwardly open discharge flap (g) in the entire width of the sieve surface , while the opposite side, also in full width, as a slide (h) is designed, which can be pushed hydraulically actuated above the floor and through the opposite opening, wherein by lowering the upper screen plate except for the slide (h) a drawer is formed. Piston press according to one of claims 1 - 3, characterized in that the ejector flap (g) and the slide (h) form an overflow valve, which no longer squeezable Rohgülle is pressed back into the feed circuit, when they each open to himself outwardly only a gap can be. Piston press according to one of claims 1 - 4, characterized in that the piston press has an outer lining, within which the filtrate is discharged Piston press according to one of the preceding claims, characterized in that the piston press operates without an electronic control operation. Piston press according to one of the preceding claims 1 - 6, characterized in that two or more of these piston presses work with only one common control in the composite.

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