WO2003013687A1

WO2003013687A1 - Filter press and filter press method

Info

Publication number: WO2003013687A1
Application number: PCT/KR2002/001507
Authority: WO
Inventors: Kwang-Soo An
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-08-08
Filing date: 2002-08-07
Publication date: 2003-02-20
Anticipated expiration: 2004-02-08
Also published as: KR20030013670A

Abstract

The present invention provides a filter press and a filter press method in which the heat generated from heating plates interposed between filter plates are transferred to a cake procuded by effecting liquid-solid separation from sludge contained within a fluid introduced between the filter plates, thereby minimizing the moisture content of the cake. Further, if necessary, the filter press of the present invention allows the drying of the cake as well as the dehydration of the cake, thereby omitting an additional drying step and providing a simple process.

Description

FILTER PRESS AND FILTER PRESS METHOD

Technical Field

The present invention relates to a filter press for effecting liquid-solid separation of sludge contained within a fluid introduced between a plurality of filter plates, and more particularly to a filter press and a filter press method for minimizing the moisture content of a produced cake and if necessary, for completely drying the cake.

Background Art

As well known to those skilled in the art, filter presses are widely used, for example, for dehydrating sludge from various industrial wastewater treatment processes, and more particularly, for dehydrating powder from various production processes such as dye, pigment, etc.

The most important object in the aforementioned filter presses is to economically and maximally reduce the moisture content of a cake produced by filter pressing. Generally, there have been proposed several filter press methods, i.e., one filter press method in which sludge on a filter plate to be pressed is dehydrated by applying a high pressure thereto by a pump so as to improve the dehydration efficiency, and another filter press method in which a pressing diaphragm is attached to a filter plate in a filter chamber to apply a pressure on sludge contained within the filter chamber of a filter press and then the pressing diaphragm is pressed by air or water so as to reduce the moisture content of the sludge.

However, the aforementioned propositions do not meet the expectations. Therefore, recently, there is used a filter press comprising a plurality of filter plates suspended or reciprocated on a guide rail in a filter chamber within a housing. Each filter plate includes a plate provided with a central feed inlet for feeding a fluid, an air supply hole formed therein, and a pressing diaphragm and a filter screen covering the outside of the plate. Herein, the filter plates are closely attached thereto, and then the fluid is introduced into the filter chamber from a fluid supply pump.

Then, air is injected into the filter chamber via the air supply hole formed on the plates of the filter plates so as to expand the pressing diaphragms formed on the outer circumference of the plates, thereby pressing the fluid between the filter plates, and enabling the liquid to be passed through a gap between the filter screen and pressing diaphragm and allow the solid to be formed between the filter plates as a cake. Next, in order to reduce the moisture content of the produced cake, air of high pressure is supplied to the filter chamber via a fluid supply line. Then, the supplied air accompanied with the moisture contained in the cake is discharged, thereby reducing the moisture content of the cake. After that, in order to further reduce the moisture content of the produced cake, the filter chamber is maintained under vacuum, thereby minimizing the moisture content of the cake. However, since this method still has a limit in reducing the moisture content of the cake, a more effective method is required. In ϋ. S. Patent No. 5,672,272, there is disclosed a method for applying steam of a pressure of lkg/cm² (at temperature of approximately 120^°C) between the plate and the pressing diaphragm of the filter plate. In this method, the steam of the pressure of lkg/cm² must be separately provided to each filter plate. In manufacturing the filter plate, since the plate is made of a hard synthetic resin and the pressing diaphragm is made of a rubber, the temperature of the supplied steam of the pressure of lkg/cm² is limited to approximately 120^°C. Further, since thermal conductivity of rubber is lower than that of the metal by approximately 100 times, a long time for transferring the heat to the pressing diaphragm is required, thereby requiring a long time for drying the cake .

Moreover, since the pressing diaphragm made of the rubber material is easily worn out within a short time due to the supplied steam of the pressure of lkg/cm², the pressing diaphragm must be frequently replaced with a new one, thereby causing inconvenience and economic burden to users .

Disclosure of the Invention

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to minimize the moisture content of a cake formed by a filter press method without any modification of the conventional filter press .

It is another object of the present invention to dry the cake produced by the filter press method.

In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a filter press method using a filter press, comprising: a filter press preparation step (SI) for interposing a heating plate between plural filter plates in a filter chamber of the filter press, closely attaching the heating plates and the filter ■ plates to each other, and introducing a fluid into the filter chamber; a first dehydration step (S2) for supplying air to the filter plates and pressing the fluid between the filter plates and the heat plates so as to enable the liquid to be discharged and allow the solid to be formed as a cake; a second dehydration step (S3) for injecting air or warm blast into the filter chamber so as to reduce the moisture content of the cake; a vacuum generation step (S4) for maintaining the filter chamber under vacuum; a drying step (S5) for heating the heating plates interposed between the filter plates so as to dry the cake; and a discharging step (S6) for discharging the dried cake to the outside.

In accordance with another aspect of the present invention, there is provided a filter press provided with a plurality of filter plates suspended or reciprocated on a guide rail in a filter chamber within a housing, each filter plate including a plate with an air supply hole, a pressing diaphragm formed outside the plate, a filter screen covering the pressing diaphragm, a central feed inlet for feeding a fluid, and an outward drainage outlet for discharging the liquid of the fluid, said filter press being characterized in that a heat supply pipe is installed on the upper end of the housing and a heat exhaust pipe is installed on the lower end of the housing, and a heating plate made of a metal is interposed between the filter plates so as to be connected to the heat supply pipe and the heat exhaust pipe via a connection pipe, the heating plate including a discharge path formed between a plurality of protrusions so as to correspond to the filter plate, a filter screen covering the discharge path, a central feed hole corresponding to the feed inlet for feeding the fluid, an outward drainage hole corresponding to the drainage outlet for discharging the liquid of the fluid, and a heat supply path formed within the heating plate.

Preferably, a heating coil may be installed within the heating plates.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a block diagram illustrating a filter press method in accordance with the present invention; Fig. 2 is a schematic view of a filter press in accordance with the present invention;

Fig. 3 is an enlarged view of Fig. 2; and Fig. 4 is an enlarged cross-sectional view of the filter press in the used state of Fig. 3. Best Mode for Carrying Out the Invention

Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings .

Fig. 1 is a block diagram illustrating a filter press method in accordance with the present invention.

As shown in Fig. 1, the filter press method of the present invention using a filter press comprises a filter press preparation step (SI) , a first dehydration step (S2) , a second dehydration step (S3) , a vacuum generation step

(S4) , a drying step (S5) , and a discharge step (S6) .

In the filter press preparation step (SI) , a heat supply channel for supplying heat or a heating plate provided with a heating coil as heating means is interposed between filter plates in a filter chamber of the filter press, and the heating plates and the filter plates are closely attached each other. Then, a fluid is introduced into the filter chamber. In the first dehydration step (S2) , air is supplied to the filter plates so as to expand a pressing diaphragm and a filter screen formed on the outer circumference of the filter plate, thereby pressing the fluid between the filter plates and the heat plates so as to enable the liquid to be passed through gaps between the filter screens and filter plates and allow the solid to be formed as a cake.

In the second dehydration step (S3) , air or warm blast is injected into the filter chamber so as to pass through the cake formed by the filter press, thereby discharging the moisture contained within the cake and reducing the moisture content of the cake.

In the vacuum generation step (S4) , the injected air into the filter chamber is exhausted so as to maintain the filter chamber under vacuum, thereby minimizing the moisture content of the cake .

In the drying step (S5) , the heating plate interposed between the filter plates is heated to transfer the heat to the cake, thereby drying the cake so as to have almost no moisture content, i.e., approximately 0%.

In the discharging step (S6) , the filter plates and the heating plates are separated from the each other, thereby discharging the dried cake formed therebetween to the outside . Herein, the heating plate is made of a metal with excellent heat and corrosion resistances. Therefore, the heating plate can be heated up to high temperature of approximately 100^°C to 300^°C. The heat of high temperature is transferred to the cake so as to minimize the moisture content of the cake. Further, the supply of the heat of high temperature of approximately 300°C shortens the heating time of the filter chamber, thereby improving the dehydration efficiency and then drying the cake.

Therefore, the above-described filter press method allows the cake to be dehydrated and if necessary, to be dried prior to the discharge of the cake, thereby not requiring any subsequent post-process phase such as a drying phase .

Fig. 2 is a schematic view of a filter press in accordance with the present invention, and Fig. 3 is an enlarged view of Fig . 2.

As shown in Figs. 2 and 3, the filter press 1 of the present invention comprises a housing 100, a filter chamber 110 installed within the housing 100, and a plurality of filter plates 50. The filter plate 50 includes a plate 55 with an air supply hole 52, a pressing diaphragm 56 formed outside the plate 55, a filter screen 58 covering the pressing diaphragm 56, a central feed inlet 55a for feeding a fluid, and an outward drainage outlet 55b for discharging the liquid of the fluid to the outside.

A heat supply pipe 10 is installed on the upper end of the housing 100, and a heat exhaust pipe 10a is installed on the lower end of the housing 100. A heating plate 20 made of a metal is interposed between the filter plates 50 so as to be connected to the heat supply pipe 10 and the heat exhaust pipe 10a via a connection pipe 12. The heating plate 20 includes a discharge path 22 formed between a plurality of protrusions so as to correspond to the filter plate 50, a filter screen 24, a feed hole 26 corresponding to the feed inlet 55a for feeding the fluid, a drainage hole 28 corresponding to the drainage outlet 55b for discharging the liquid of the fluid, and a heat supply path 20a formed within the heating plate 20.

Herein, the heating plate 20 is preferably made of a metal with excellent heat and corrosion resistances, thereby not being deformed even under the high temperature of approximately 100^°C to 300^°C. Therefore, the heating plate 20 can be heated up to the high temperature.

Instead of the heat supply path 20a, a conventional heating coil may be used in the heating plate 20, thereby directly generating heat via an electrical source and more quickly heating the heating plate 20.

By using the aforementioned heating coil, the heating plate 20 may be simple in structure and quickly heated in a short time.

Fig. 4 is an enlarged cross-sectional view of the filter press in the used state of Fig. 3.

As shown in Fig. 4, the filter plates 50 and the heating plates 20 are closely attached to each other in the filter chamber 110, and then the fluid is introduced into the filter chamber 110. Air is supplied to the filter chamber 110 via the air supply holes 52 of the plates 55 of the filter plates 50. Then, as shown in the one-dot chain line in Fig. 4, the pressing diaphragms 56 and the filter screens 58 are expanded by the supplied air, thereby pressing the fluid between the filter plates 50 and the heating plates 20 so as to enable the liquid to be discharged and allow the solid to be formed as a cake .

Then, air or warm blast is injected into the filter chamber 110 via the feed inlet 55a, thereby discharging the air or the warm blast accompanied with the moisture contained within the cake. Next, the filter chamber 110 is maintained under vacuum, thereby minimizing the moisture content of the cake . Heat is supplied to the heating plates 20 interposed between the filter plates 50 via the heat supply path 20a to heat the heating plates 20. Heat generated by the heating plates- 20 is transferred to the cake, thereby drying the cake so as to have almost no moisture content of approximately 0%.

Therefore, the aforementioned filter press allows the cake to be dehydrated so as to have the minimum moisture content, and then if necessary, to be dried.

After the filter pressing and drying steps are completed, the filter plates 50 are separated from the heating plates 20 and the dried cake is discharged to the outside. Then, the filter pressing process of the present invention is completed.

Industrial Applicability

As apparent from the above description, the present invention provides a filter press and a filter press method in which the heat generated from heating plates interposed between filter plates are transferred to a cake produced by effecting liquid-solid separation from sludge contained within a fluid introduced between the filter plates, thereby minimizing the moisture content of the cake.

Further, if necessary, the filter press of the present invention allows the drying of the cake as well as the dehydration of the cake, thereby omitting an additional drying step and providing a simple process .

Moreover, since the heating plate is constructed to have a shape corresponding to that of the filter plate, the present invention may be applied to the conventional filter press as it is, thereby providing convenience to users.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims .

Claims

Claims :

1. A filter press method using a filter press, comprising: a filter press preparation step (SI) for interposing a heating plate between plural filter plates in a filter chamber of the filter press, closely attaching the heating plates and the filter plates to each other, and introducing a fluid into the filter chamber; a first dehydration step (S2) for supplying air to the filter plates and pressing the fluid between the filter plates and the heat plates so as to enable the liquid to be discharged and allow the solid to be formed as a cake; a second dehydration step (S3) for injecting air or warm blast into the filter chamber so as to reduce the moisture content of the cake; a vacuum generation step (S4) for maintaining the filter chamber under vacuum; a drying step (S5) for heating the heating plates interposed between the filter plates so as to dry the cake; and a discharging step (S6) for discharging the dried cake to the outside.

2. A filter press provided with a plurality of filter plates suspended or reciprocated on a guide rail in a filter chamber within a housing, each filter plate including a plate with an air supply hole, a pressing diaphragm formed outside the plate, a filter screen covering the pressing diaphragm, a central feed inlet for feeding a fluid, and an outward drainage outlet for discharging the liquid of the fluid, said filter press being characterized in that a heat supply pipe is installed on the upper end of the housing and a heat exhaust pipe is installed on the lower end of the housing, and a heating plate made of a metal is interposed between the filter plates so as to be connected to the heat supply pipe and the heat exhaust pipe via a connection pipe, the heating plate including a discharge path formed between a plurality of protrusions so as to correspond to the filter plate, a filter screen covering the discharge path, a central feed hole corresponding to the feed inlet for feeding the fluid, an outward drainage hole corresponding to the drainage outlet for discharging the liquid of the fluid, and a heat supply path formed within the heating plate.

3. The filter press as set forth in claim 2, wherein a heating coil is installed within the heating plates.