FI100225B - Apparatus for separating liquid from solid - Google Patents

Description

100225

Apparatus for separating liquid from solid - Anläggning för att separera en vätska frän ett fast amne 5 Known presses for separating water from fibrous solid are practically all based on drum, screw, filter belt, roller or disc technology. Different types are characterized by certain operating parameters and the consequent ideal operating conditions. Screw presses have become more common, especially in sludge applications. However, they have clear drawbacks, especially when the material 10 to be compressed should be made very dry. If the material is still abrasive or its friction properties change over time, the use of a screw press can prove difficult. This is due to the discrepancy between the operating principle of the screw press and the high pressure required to achieve a high final dry matter content. High pressure has to be developed by reducing the area of the outlet of the compressed material with a special adjustable (self-adjusting) equipment in order to achieve a (constant) pressure. Generally, this device is a cone to be pressed against the screw outlet or a flap hinged on one side, which is pressed in the direction of material flow from the latter side against the material flow. As a result of the limitation of the area of the outlet, the screw becomes easily blocked when the pressure is increased.

20

However, the screw press is an excellent bulk drain, as its hydraulic specific drainage capacity is easy to build very large.

The pressure inside the screw can also be developed by changing the pitch of the screw or making the screw shaft conical, but this solution always requires a 100% degree of filling to operate stably and is also disadvantageous in terms of clogging.

Solutions with separate low and high pressure presses are also known. One such solution is presented in FI publication 71006. In known solutions, however, the high-pressure head of the low-pressure press 30 is not directly connected to the supply of the high-pressure press.

The material from the screw press can, if desired, be transported to a special high-pressure press, which can be, for example, a drum press. In the drum boom-35 cross under the press roll, a very high pressure can be generated on a smaller surface area, with which it is possible to achieve a high final dry matter content. On the other hand, the hydraulic specific dewatering capacity of the drum press is difficult to make large because the pressing event under the roll is short-lived and the pressurized surface area in use is quite limited.

100225 2 However, such a double-press solution becomes quite expensive, as two separate presses with intermediate conveyors cost a lot compared to the capacity.

The object of the invention is to eliminate this drawback and to provide a method by which low and high pressure compression can be effectively combined into a preferred combination with a higher dewatering capacity than the separate units.

Characteristic features of the apparatus according to the invention are set out in claim 1.

10 This object can be achieved by installing a low-pressure press and a high-pressure drum press in Saija so that the high-pressure end of the low-pressure press joins the supply of the high-pressure part directly. With a suitable control system, the low-pressure press is always driven slightly faster in terms of volume capacity than the high-pressure section, whereby the low-pressure section develops pressure for the supply of the high-pressure section. In this case, pressure is generated both in the low-pressure part and in the drum press inside the part of the drum preceding the nip. This is now the extra pressurized hole area that can be used for drying. On the other hand, the size of the material outlet has not had to be limited in any way and the pressure development can be regulated by means of the control system 20 on the basis of the speed difference and / or the pressure sensors.

In the following, the invention will be described in more detail by way of example with reference to the accompanying drawings, which illustrate one possible mode of exploitation.

v 25 Figure 1 shows a side view of the apparatus according to the invention, partly in section.

Figure 2 shows the equipment as seen from the end.

Figure 3 shows the apparatus so as to show the supply of material to be dried by means of a screw-press 30 to a drum press.

«·

The low pressure part 2 is a screw clamp. A drum press 1 is mounted on its outlet as a high pressure section. The rotation speed of the screw is controlled by system 3 based on two pressure sensors, 6 and 7 in the example. The pre-compression pressure thus develops inside the screw 2 and in the space 5. The pressurized area is marked with a score. If a drum press which presses only once is used, the pressurized tl 3 100225 area extends over the entire pressing width and the escape of the material to be pressed from one end is prevented by a barrier plate similar to that at the inlet end. The drum press is particularly well suited as a high-pressure press after the screw press, because in any case the material to be pressed has to be fed into the drum 5 by a screw conveyor and because it is possible to pressurize a large additional area at least in both the drum and the roll.

The method works, for example, by adjusting the speed of the screw according to the material flow by means of a pressure sensor 6 in the screw casing in order to achieve the highest possible degree of filling. The sensor 7 in the high-pressure press, on the other hand, reduces the volume capacity of the high-pressure press by reducing the rotational speed or by thinning the nip if the pressure in the space 5 decreases and vice versa.

The functionality of the method is in no way tied to press-15 structures just as described above, but can be applied to many other combinations as long as they are physically interconnected.

Depending on the situation and the application, the piston press can be either a low or high pressure press. It can be used to feed high pressure presses. There may be several pistons 20.

Instead of pressure sensors, for example, a force measurement connected to the end shutter plate of the drum or to the plow 4 can be used. The screw pressure can also be examined by measuring the axial force of the screw shaft bearing, the shaft torque or the current consumption of the drive motor.

• I

Claims (4)

4,100225 1. Applying the separator and the pressure to the fasteners, the colors to which the pressure is pressed (2), exempting the screws, to the pressure to the pressure, and the cylinder (1) to the three-dimensional pressure, the same assembly is sequentially equipped with a cylinder head pressurized to the cylinder head of the cylinder assembly, the headforms of which are pressurized to the cylinder presses (30) (2) that the aggregate (4), in which case a part of the cylinder is rolled with a cylinder and a cylinder and a tracer pressed at the back of the tricket, is used to move the cylinder to the cylinder or through the shaft. An apparatus for separating a liquid from a solid, the apparatus comprising a low pressure press (2), e.g. that the low pressure press (2) generates pressure on itself and inside the drum press (1) and that the drum press has a body (4) between the drum and the roll or at the drum outlet, covering most of the cross-sectional area between the roll and the drum and preventing the low pressure press from escaping towards or from the discharge end. 2. A method according to claim 1, comprising a pressure press with a screw press (2). il 35 5 100225 Apparatus according to Claim 1, characterized in that the low-pressure press is a screw press (2). 15 3. An invention according to claim 1 or 2, comprising a cylinder press with a multi-press method. Apparatus according to Claim 1 or 2, characterized in that the drum press is based on a multi-pressing method. Apparatus according to one of Claims 1 to 3, characterized in that the speed of rotation or the size of the drain of the low-pressure press (2) and the drum press (1) is controlled by the control system (3), e.g. by means of pressure or force sensors (6, 7). 4. Anlamging enligt nägot av patentkraven 1-3, kännetecknad av att lägtrycks-5 Pressens (2) och cylinders (1) rotationshastighet eller gapets storlek regulleras av ett reglersystem (3) t.ex. with a trickgivare or a dynamometer (6, 7). • I