DE7435463U - Pressure filter for pulp - Google Patents

Description

■ -: PATENTANWÄLTE r

HENKEL, KEkW; FFEÜER & HÄNZEL

BAVARIAN MORTGAGE AND

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m'nchbn ^D - ⁸⁰⁰⁰ MÜNCHEN 90 Postscheck: München «,, 7 - so,

Alfonso Galletti
Turin, Italy

1 3rd OCT.

Pressure filter for pulp

The innovation relates to a pressure filter for sludge with a flow through which the liquid to be cleaned flows Filter element between an inlet chamber for the pulp and an outlet chamber for the purified liquid is switched on

The innovation relates specifically to filters of the type in which the filter element is not used frequently or regularly Needs to be replaced, but cleaned regularly must be when it has reached such a silting or clogging degree that the liquid flow by which the filter element is adversely affected. This cleaning is generally done by a countercurrent flushing process using the filtered liquid or the liquid to be purified. To carry out this flushing process must have suitable pipelines, valve systems and the like to reverse the flow of liquid be provided by the filter element.

If the flushing process is carried out under manual control, it is particularly time consuming and troublesome, and it requires considerable downtime for the filter.

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The task of the innovation is therefore to avoid the disadvantages and difficulties mentioned by creating a filter of the type outlined above wherein countercurrent purging of the filter element is provided by means which are simple and robust and which work quickly and precisely, without long downtimes the device in which the filter is installed or longer interruptions in normal filtering operations.

In a pressure filter for pulp, this object is achieved according to the invention in that it has an outer chamber an inlet line for the pulp to be cleaned, that the outer chamber is closed at the bottom by a drain valve, that an inner chamber is provided which is coaxially enclosed by the outer chamber and is delimited by a tubular member, the upper part of which extends over the outer chamber protrudes and is in communication with an outlet pipe and the lower part of which has a perforated wall which a filter element for filtering the pulp as it flows from the outer chamber into the inner chamber carries, and that a is provided within the inner chamber axially movable piston, which at its upper end with a Druckfluidum-Betätlgungselement and at its lower end via a rigid connecting member is connected to the drain valve, and that the Druckfluidum actuating element by a Pressure switch is controllable, which responds to the pressure in the outer chamber of the filter, an increase in this pressure to a predetermined value as a result an increasing clogging of the filter element results in an actuation of the actuating element in order to rapidly extend the piston in the downward direction into the inner chamber and to expel the already filtered liquid contained in this chamber from the chamber, wherein

this liquid flows through the filter element in the opposite direction to the normal flow direction during filtering and it flushes away deposits from the filter element, the downward displacement of the piston over the connecting member also an opening of the bottom drain valve has the consequence, so that the deposits removed from the filter element during the countercurrent flushing process are expelled from the outer chamber, whereupon the actuating element automatically returns to its rest position to allow normal filtering operation of the filter.

As a result of the automatic mode of operation of the pressure fluid actuating element, the filter according to the invention thus offers particular practical advantages when the filter element is blocked "

In the following, a special embodiment of the innovation is explained in more detail with reference to the accompanying drawing. Show it:

1 shows a schematic axial section through a print filter according to the innovation in normal operating condition,

Flg. FIG. 2 is a view similar to FIG. 1 showing the filter during the reverse flow flushing process, and FIG

FIG. 3 shows a section along the line III-III in FIG. 1.

The pressure filter according to the invention has an inner chamber A which is defined by an inner cylindrical tubular member 1 is, the lower part has a perforated wall with radial openings 2, which in turn through a the tubular member according to the type of liquid to be filtered and the size of the contamination to be retained by the filter

cleaning selected filter element 3 are closed. The cylindrical tubular member 1 is on its rear fascia closed by a transverse bottom wall 4, the is provided with a central gate or approach, while ropes upper end through a transverse flange 5 with a central sprue or extension is closed »The upper part of the chamber A communicates with an outlet pipe 6 extending radially outward.

The perforated lower wall of the tubular member 1 is surrounded by an outer annular chamber B, which is delimited by a cylindrical jacket or the same 7, which is closed at the upper end by a sealing flange θ «The housing 7 has a frustoconical, Wall 9 which tapers downward and merges into an opening which is normally closed by a drain valve 10. The latter consists of a frustoconical closure member which is slidably placed on a shaft 12 and is loaded by a spring 11 supported on an outwardly protruding edge of the shaft 12. The shaft 12 extends along the common axis of the tubular member 1 and the housing 7 over the entire length of the filter. The drain valve 10 opens automatically as soon as the prevailing in the outer chamber B by the. Internal pressure exerted on it exceeds the reaction force of the spring * ^A.

The shaft 12 acts a "! - connecting link, since it is attached to his The upper end is connected to a piston 13 which is guided in the inner chamber A so as to be displaceable with a seal. The piston 13 is supported by a rod 14 of a pressurized fluid actuator 15, in the illustrated embodiment a pneumatic actuator carried on the Upper side of the final transverse flange 5 is arranged. A

flexible bellows 16 protects the rod 14 of the actuator 15 to prevent liquid from escaping through the upper transverse flange 5 < > The actuating element 15 is controlled by a pressure switch, not shown controlled, which is responsive to the pressure prevailing in the outer chamber B of the filter.

The outer chamber B communicates with a tangential inlet line 7a, via which the liquid to be cleaned is fed in during normal operation of the filter.

Among the normal. Operating conditions is the filter in the state shown in Fig. 1, in which the lower drain valve 10 is closed and the piston 13 is at the top of its stroke. The ones about the Line 7a introduced into the outer chamber B is distributed over the entire outer chamber and flows radially inward through the filter element 3 »to then enter the inner chamber A, from which it is via the outlet pipe 6 flows off.

If the filter element 3 is clogged, so that the pressure prevailing in the outer chamber B rises and finally reaches a predetermined maximum value, the pressure switch, not shown, actuates the actuating element 15, so that the piston 13 and the shaft 12 connected to it are quickly extended downward as shown in FIG. By this axial displacement of the piston 13, the outlet pipe 6 is separated from the inner chamber A, and the already filtered, Liquid contained in the lower part of the inner chamber A is then expelled through the piston 13 at high speed the inner chamber A pushed out, the filter element 13 opposite to the normal flow direction when It flows through the filters and washes away the deposits on the outer surface. At the same time, the

Downward movement of the shaft 12 opens the lower drain valve 10 so that the flushed away from the filter element Deposits entrained liquid on the underside of the filter is discharged without mixing with the inflowing liquid to be filtered.

Once countercurrent purging of the filter element is complete, the pressurized fluid actuator 15 pulls the Piston 13 back to its original rest position, the drain valve 10 closes and the filter is returned to the normal operating condition.

The rinsing of the filter element can also be done manually Control takes place by actuating the control elements of the actuating element 15

From the above description it can be seen that the countercurrent flushing of the filter takes place fully automatically and within a very short time, without having to resort to complicated arrangements of additional pipelines and valves ₉ by adding the filter components with the addition of an actuator controlled by an actuator or an actuator Piston can be used.

Various modifications and changes to the illustrated and described embodiment will be apparent of the innovation possible without deviating from the framework and basic idea of the innovation

Claims (1)

G Ik 35 463.5 Alfonso Gallstti November 21, 1974 ut ζ a η proverbs Pressure filter for pulp, characterized that it has an outer chamber (B) with an inlet line (7a) for the pulp to be cleaned, that the outer chamber is closed at the bottom by a drain valve (10) that is coaxial with the outer chamber by = closed inner chamber (A) is provided, which is bounded by a tubular member (1), the upper part of which over the Outer chamber protrudes and is connected to an Aasia pipe (6) in Connection and its lower part a perforated wall! having a filter element (3) for filtering the Turbidity in its malfunction carries from the outer chamber into the inner chamber, and that an axially inside the inner chamber movable piston (13) is provided, which at its upper end with a pressure fluid actuating element (15) and is connected at its lower end to the drain valve (10) via a rigid connecting member (12), and that the Druckfluidum actuating element (15) by a Pressure switch is controllable, which responds to the pressure prevailing in the outer chamber (B) of the filter, at its caused by increasing clogging of the filter element Increase to a predetermined value a rapid downward movement of the piston into the inner chamber (A) the can be triggered and the pressure / already filtered liquid in the chamber is increased to such an extent that the Filter element opposite to the normal direction of flow and at the same time flushing away the clogging deposits can be flowed through, and that the drain valve is set such that / under the increased pressure of the filtered Liquid opens to expel the deposits, and that the actuating element after the pressure relief given thereby can be automatically reset to its starting position for normal filter operation. -U- 2 · Pressure filter according to claim 1, characterized in that the pressure fluid actuating element (15) has a movable rod (14), one part of which sieves. In the Innenkaunier (A) of the filter extends and is protected by a flexible bellows (16), which at its lower end with the piston (13) and at the upper end with the ■. Inner chamber (A) closing upper end wall (5) closed 1st. ; '.--- -. ν '.-.' .. .. 3 «pressure filter according to claim 1 or 2, characterized in that that the displaceable piston (13) during the initial phase its downward stroke the connection between the inner ■■ .. chamber (A) and the outlet pipe (6) interrupted. 4 · Pressure filter according to one of Claims 1 to 3, characterized in that the . . Eehene drain valve (10) slidably mounted on the connecting member (12) connected to the actuating element (15) and through a. elastic or spring means is loaded (11) so that it is able to automatically open when the force by the pressure prevailing in the outer chamber (B) pressure exerted on it the Vorbelastun ^ ski ^s aft of the resiliently ttelß exceeds. ... ■ -