JP2004025138A - Dehydration and drying method using filter press apparatus and filter press apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely bring out a desired effect of dehydration and drying. <P>SOLUTION: The dehydration and drying is performed by providing the peripheral edges of filter cloth 4 with continuous annular sealing parts r so as to enclose filter chambers 6 and tightly bonding the peripheral edges of filter plates 2 and 3 to each other by means of the annular sealing parts r, then by heating the sludge supplied into the filter chambers 6 by means of heating panels H and by evacuating the interior of the surface regions of the filter plates enclosed by the annular sealing parts thereby evaporating the moisture of the sludge. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dehydration drying method using a filter press apparatus and a filter press apparatus.
[0002]
[Prior art]
In the above Japanese Patent Application Laid-Open No. 2000-153103, the present applicant dehydrated the sludge supplied to the filter chamber between the filter plates while keeping the temperature in the sludge heating section and evacuating the filter chamber through the filtrate discharge path. A technique for drying is proposed. In this prior art, moisture in the sludge evaporates and dehydration drying is promoted by an appropriate balance between the heat retention of the sludge and the degree of vacuum in the filter chamber.
[0003]
[Problems to be solved by the invention]
In the above prior art, the balance between heating and vacuum suction is important, and even if heating is appropriate, if the vacuum suction is insufficient, the desired dehydration drying effect cannot be obtained. However, if the filter cloth is simply held between the peripheral edges of the filter plate, air is introduced from the outside through the filter cloth holding portion when the filter chamber is vacuumed, and the filter chamber is brought to a desired degree of vacuum. It was difficult to keep. As a result, even if the apparatus is intended to be operated under appropriate conditions, the desired dehydrating and drying effect may not be obtained.
[0004]
Therefore, a main problem of the present invention is to ensure that the desired dehydration drying effect is exhibited.
[0005]
[Means for Solving the Problems]
The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A filter chamber formed between the filter plates, each having a pair of filter cloths in the filter chamber, and a sludge heating section for heating the sludge supplied into the filter chamber by heat exchange with the heat medium, A dehydrating and drying method using a filter press that supplies a heat medium to a sludge heating unit and vacuum-sucks each filter chamber to evaporate moisture in the sludge to perform dehydration drying,
At least one of the peripheral edge of the filter plate and the peripheral edge of the filter cloth is provided with a continuous ring-shaped seal portion so as to surround the filter chamber,
While closely adhering the peripheral parts of the filter plate through the ring-shaped seal part,
The vacuum suction is performed from within the filter plate surface area surrounded by the ring-shaped seal portion,
The dehydration drying method using the filter press apparatus characterized by the above-mentioned.
[0006]
(Function and effect)
Thus, in the present invention, after the peripheral portions of the filter plates are brought into close contact with each other via the ring-shaped seal portion, the vacuum suction is performed from within the filter plate surface region surrounded by the ring-shaped seal portion while heating the sludge. By doing so, the filter chamber is maintained at a desired degree of vacuum. As a result, according to the present invention, the balance between the heating and the degree of vacuum is appropriately maintained, and the desired dehydration drying effect is reliably exhibited.
[0007]
<Invention of Claim 2>
A filter chamber formed between the filter plates, each having a pair of filter cloths in the filter chamber, and a sludge heating section for heating the sludge supplied into the filter chamber by heat exchange with the heat medium, This is a filter press device configured to perform dehydration drying by supplying a heat medium from a common heat medium supply source to the sludge heating unit and vacuuming the filter chamber to evaporate water in the sludge. And
At least one of the peripheral edge of the filter plate and the peripheral edge of the filter cloth is provided with a continuous ring-shaped seal portion so as to surround the filter chamber,
While configured so that the peripheral portions of the filter plates are in close contact with each other via the ring-shaped seal portion,
The vacuum suction is made from the inside of the filter plate surface area surrounded by the ring-shaped seal portion,
The filter press apparatus characterized by the above-mentioned.
[0008]
(Function and effect)
The same effect as that of the first aspect of the invention can be achieved.
[0009]
<Invention of Claim 3>
The ring-shaped seal portion is provided only at the peripheral portion of the filter plate, and the filter cloth is configured to be disposed only in a region closer to the center than the ring-shaped seal portion at least during the vacuum suction. The filter press apparatus according to claim 2.
[0010]
(Function and effect)
The form in which the ring-shaped seal portion is provided only at the peripheral portion of the filter plate is very preferable because of its simple structure. In this case, even if the peripheral portions of the filter plate are brought into close contact with each other via the ring-shaped seal portion, the seal If the filter cloth is pinched by the portion, outside air leaks into the filter chamber through the filter cloth. Therefore, by configuring as in the third aspect of the present invention, the filter cloth is not held by the seal portion, and the sealing performance of the ring-shaped seal portion can be sufficiently exhibited.
[0011]
<Invention of Claim 4>
The pressure air is supplied between the filter cloth and the filter plate, and the filter cloth is bulged with respect to the filter plate so that the cake attached to the filter cloth is peeled off. The filter press apparatus of Claim 1.
[0012]
(Function and effect)
In a conventional general filter press apparatus, the dewatered and dried cake stuck to the filter cloth is peeled off and discharged by winding the filter cloth or mechanically scraping the filter cloth, but the filter cloth is quickly damaged. And problems such as complicated device configuration.
[0013]
The invention described in claim 4 solves such a problem. By supplying pressurized air between the filter cloth and the filter plate and causing the filter cloth to bulge against the filter plate, It is to peel off the attached cake. In the invention described in claim 4, since there is no friction against the filter cloth, the filter cloth is not easily damaged, and no scraping device is required. Since it is sufficient to add a compressor or the like for supplying the apparatus, the apparatus configuration is greatly simplified.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<First Embodiment>
FIG. 1 shows a front view of a filter press apparatus example 1 according to the present invention. As shown in FIG. 2, the apparatus 1 includes a heating filter plate 2 in which each filter cloth 4 is provided with sludge heating portions H and H on its side, and a non-heating filter plate 3 having no sludge heating portion. These are arranged alternately in the horizontal direction in a posture along the vertical direction, and belong to the horizontal type from the arrangement form of the filter plates.
[0015]
In addition, this device example 1 belongs to a so-called intaglio type, and each filter plate 2 and 3 is formed with recesses 2a and 3a on the surface facing the adjacent filter plates 2 and 3, respectively. A pair of filter cloths 4, 4... Are suspended between the plates 2 and 3, respectively.
[0016]
These filter plates 2, 3... Are connected to adjacent filter plates via connecting members 109, 109, and the mutual interval is adjusted by a cylinder 5 that expands and contracts in the horizontal direction. Therefore, in this state, the filter plates 6 are formed between the recesses 2a and 3a of the adjacent filter plates 2 and 3 by bringing the adjacent filter plates 2 and 3 into contact with each other by tightening the cylinder 5 and tightening. As a result, the pair of filter cloths 4, 4 are held in a bag shape in the filter chamber 6.
[0017]
Details of the heating filter plate 2 are shown in FIGS. 2 and 3 (the filter cloth 4 is omitted in FIG. 3). In the recesses 2a and 2a of the heating filter plate 2, a pair of heating panels H and H as a sludge heating unit of the present invention are attached to substantially the whole with a slight gap therebetween. The heating panel H in the illustrated example is hollow, and a heat medium supply path 2F for supplying a heat medium from the outside through the inside of the filter plate 2 is communicated with the lower end portion of the side surface of the filter plate 2 and the filter plate. A heat medium discharge path 2E for discharging the heat medium to the outside through the inside of the filter plate 2 is communicated with the upper ends of the two side surfaces. Further, a flow meter 20 and a flow rate adjusting valve 21 are respectively provided in both the heating medium supply path 2F and the heating medium discharge path 2E of each heating filter plate 2 so that the heating medium flow rate for each heating filter plate can be adjusted. It has become. Thus, the heat medium can be supplied from the outside to the lower end portion of the heating panel H, the inside of the heating panel H can be raised, and the used heat medium can be discharged from the upper end portion of the heating panel H to the outside.
[0018]
Further, the inlet of the filtrate discharge path 2X is opened at the upper and lower edges of the recesses 2a, 2a of the heating filter plate 2 and communicated with the inside of the filter chamber 6 through a gap with the heating panel H. The filtrate discharge path 2X is connected to a vacuum suction device (not shown) (for example, a vacuum suction pump connected to the filtrate discharge path and a storage tank for storing the sucked filtrate).
[0019]
On the other hand, the details of the non-heated filter plate 3 are shown in FIGS. 2 and 4 (the filter cloth 4 is omitted in FIG. 4), and the structure for heating in the heated filter plate 2 is shown. The configuration is omitted.
[0020]
Furthermore, the present apparatus example 1 belongs to a so-called center feed type, and sludge supply holes SF penetrating in the thickness direction are formed in substantially central portions of the heating filter plate 2 and the non-heating filter plate 3, respectively. . Further, the filter cloths 4 and 4 arranged on one side and the other side of the filter plates 2 and 3 are connected to each other through a communicating portion passing through each sludge supply port SF, and an upper end portion thereof is A support bar 108 provided on the filter plates 2 and 3 is supported in a suspended state.
[0021]
Characteristically in the first embodiment, as shown in FIGS. 2, 5 and 6, the filter cloth 4 is filtered at the peripheral edge (the part excluding the part corresponding to the concave parts 2a and 3a of the filter plate). A continuous ring-shaped seal portion r is provided so as to surround the chamber 6. For example, as shown in FIG. 6, the ring-shaped seal portion r can be formed by impregnating a predetermined portion of the filter cloth 4 with an elastic seal material g (for example, rubber or soft resin) such as resin. Further, in this case, the elastic sealing material g may be exposed on the surface of the filter cloth 4, but the peripheral edge portion of the filter cloth 4 is sandwiched between the peripheral edge portions of the filter plates 2 and 3, and in that case, sufficient sealing performance is obtained. Therefore, even if there are some voids in the filter cloth, sufficient sealing performance is exhibited.
[0022]
In the apparatus 1 configured as described above, sludge can be dehydrated and dried as follows, for example. First, the filter plates 2, 3... Are tightened and closed by extension of the cylinder 5 (shown only in FIG. 1) to form a filter chamber 6 as shown in FIG. At this time, since the peripheral portions of the filter plates 2 and 3 are brought into close contact with each other via the ring-shaped seal portion r, the filter chamber 6 is surely and sufficiently sealed.
[0023]
Thereafter, the heating medium supply device (not shown) is operated to circulate the heating medium through the heating panels H and H, and the sludge supply device (not shown) is further operated before or simultaneously with this, so that the sludge is sludged. Pressure is supplied between the filter cloths 4 and 4 in the filter chamber 6 through the supply path SF.
[0024]
The sludge supplied into the filter chamber 6 is passed through the filter cloths 4 and 4 only by the sludge supply pressure, and the dehydration proceeds. At this time, the heat of the heating medium passing through the heating panels H and H is transmitted to the sludge between the filter cloths 4 and 4, and the dewatering proceeds while the sludge is heated.
[0025]
In such dehydration, the inside of the filter chamber 6 is vacuum-sucked from the inside of the filter plate surface region surrounded by the ring-shaped seal portion r via the filtrate discharge path 2X by a vacuum suction device (not shown) in the present invention, and the vacuum state (negative pressure state ). Thereby, the water | moisture content in sludge evaporates and dehydration drying is accelerated | stimulated. This vacuum suction can always be performed at the time of sludge dewatering, or can be performed only for an arbitrary period.
[0026]
In any case, since the ring-shaped seal portion r is provided at the peripheral edge of the filter cloth 4 as described above during the vacuum suction, the filter chamber 6 is surely and sufficiently sealed, and the inside of the filter chamber 6 is completely sealed. A desired vacuum level is maintained. As a result, according to the present invention, the balance between the heating and the degree of vacuum is appropriately maintained, and the desired dehydration drying effect is reliably exhibited.
[0027]
On the other hand, when the dehydration drying is completed and the dehydration dry cake is formed in the filter chamber 6, the discharge process is then started. The discharging process is the same as that of the second embodiment described below, and will be described together with the second embodiment.
[0028]
<Second Embodiment>
In the first embodiment, the ring-shaped seal portion r is provided on the peripheral edge of the filter cloth 4, but in the present invention, a ring-shaped seal portion R can be provided on the peripheral edge of the filter plate as shown in FIG. .
[0029]
More specifically, in the illustrated example, a ring-shaped seal portion R is provided on the peripheral edge of the surface of the heated filter plate 2 facing the non-heated filter plate 3. Although not shown, conversely, a ring-shaped seal portion R can be provided at the peripheral portion of the surface of the non-heated filter plate 3 facing the heated filter plate 2. The ring-shaped seal portion R can be provided by fitting and fixing a ring-shaped seal material made of an elastic seal material such as resin (for example, rubber or hollow resin) in a mounting groove provided on the surface of the filter plate 2. it can.
[0030]
Also, characteristically, the filter cloths 4, 4 are arranged only in the region closer to the center than the ring-shaped seal part R, so that the filter cloths 4, 4 are not sandwiched by the seal part R. It has become. As a result, the problem of external air leaking into the filter chamber 6 through the filter cloth as in the case where the filter cloth is sandwiched by the seal portion R is fundamentally solved, and the sealing performance of the ring-shaped seal portion R is sufficient. Will come into play.
[0031]
For this reason, in the second embodiment, as shown in FIGS. 8 and 9, the size of the filter cloths 4 and 4 is accommodated in the ring-shaped seal portion R, and the upper end of the filter cloths 4 and 4 is attached to the filter cloth. It is suspended from the support bar 108 via a support material 8 having a higher airtightness (even more preferably thinner) than the support member 8. Thus, the filter cloth 4 on the heated filter plate 2 side or the filter cloth 4 on the non-heated filter plate 3 side is not pinched by the ring-shaped seal portion R. The support material 8 of the filter cloth 4 is sandwiched between the ring-shaped seal portions R. However, since this is more airtight than the filter cloth 4, the airtightness of the filter chamber 6 is not impaired.
[0032]
Other configurations (including the dehydration drying method and the cake discharge method) in the second embodiment are basically the same as those in the first embodiment, and thus the same reference numerals are given and description thereof is omitted.
[0033]
Here, the cake discharging method in the apparatus of the first and second embodiments will be described. First, as shown in FIG. 1, the loose head 101 is opened by contraction of the cylinder 5, and the filter plates 2 connected to each other are connected. 3 are sequentially pulled to open the frames so that the distance between the filter plates 2 and 3 is a constant interval. At this time, the support bar 108 moves to approximately the center between the filter plates 2 and 3. As a result, as shown in FIG. 10, since the filter cloths 4 and 4 are restrained by the filter plates 2 and 3 only at the position of the sludge supply port SF, the portion below the sludge supply hole SF position of the filter plates 2 and 3 However, with the movement of the filter plates 2 and 3, the filter plate is moved away from the suspension position by the support bar 108, and the cake is discharged by its own weight.
[0034]
<Third Embodiment>
In the dehydration drying of the present invention, cake sticking to the filter cloth is less than that of conventional dehydration alone, so that the cake can be discharged by a simpler method. Therefore, the third embodiment employs a novel cake discharging method.
[0035]
That is, in the third embodiment, as shown in FIGS. 11 and 12, when discharging the cake, pressurized air is supplied between the filter plates 2 and 3 and the filter cloth 4 via the filtrate discharge paths 2X and 2X. The filter cloth 4 is bulged with respect to the filter plates 2 and 3, respectively. Due to the swelling of the filter cloths 4 and 4, the pressure air passing through the filter cloths 4 and 4 acts as an auxiliary, and the cake attached to the filter cloths 4 and 4 is peeled off.
[0036]
Thus, the dehydrated and dried cake formed between the filter cloths 4 and 4 can be peeled off and discharged from the filter cloths 4 and 4 without winding up the filter cloth or mechanically scraping. Therefore, since there is no friction with respect to the filter cloth 4, the filter cloth is hardly damaged. In addition, since a scraping device is not necessary and a flow path for vacuum suction can be used, there is an advantage that it can be implemented with a simple configuration by simply adding a compressor or the like for supplying pressurized air to the flow path. is there.
[0037]
In the third embodiment, since the filter cloths 4 and 4 are fixed and supported only by the corresponding filter plates 2 and 3, no additional devices such as the support bar 108 and the support material 8 are required, and the ring There is also an advantage that even better sealing performance is exhibited because nothing is sandwiched between the sealing portion R and the filter plate 3 and both come into direct contact with each other.
[0038]
<Fourth Embodiment>
The first embodiment and the second embodiment are combined, and as shown in FIG. 13, a ring-shaped seal portion r is provided on the peripheral portion of the filter cloths 4 and 4, and at the corresponding position on the peripheral portion of the filter plate 2. Alternatively, the ring-shaped seal portion R may be provided so that the peripheral portions of the filter plates are in close contact with each other via the ring-shaped seal portion r of the filter cloths 4 and 4 and the ring-shaped seal portion R of the filter plate 2 ( Fourth embodiment). In this case, the peripheral edge portion of the filter cloth 4, 4 is sandwiched by the ring-shaped seal portion R, but the filter cloth 4, 4 itself is also provided with the ring-shaped seal portion R. , 4 hardly leaks air.
[0039]
<Others>
In the above description, the present invention has been shown to be applied to a filter cloth hanging type, but it can also be applied to a filter cloth traveling type dehydrator. Further, in the present invention, in addition to the center feed that supplies the heated sludge from the center of the filter plate, it may be the upper feed that supplies the sludge from the upper part of the filter plate, or the under feed that supplies the sludge from the lower part of the filter plate. it can.
[0040]
Furthermore, in the present invention, the opening / closing of the valve, the start / stop of the pump, the closing / opening of the frame by the cylinder, etc. in the above-described specific example can be performed automatically by an appropriate control device.
[0041]
【The invention's effect】
As described above, according to the present invention, the desired dehydration drying effect can be reliably exhibited.
[Brief description of the drawings]
FIG. 1 is a front view of a filter press device according to a first embodiment.
FIG. 2 is an enlarged vertical sectional view of a main part.
FIG. 3 is a view showing a heated filter plate surface.
FIG. 4 is a diagram showing the surface of a non-heated filter plate.
FIG. 5 is a view showing a filter cloth surface.
FIG. 6 is an enlarged vertical cross-sectional view showing a state where the filter plate is held by a peripheral edge portion.
FIG. 7 is an enlarged vertical cross-sectional view of a main part of a filter press device according to a second embodiment.
FIG. 8 is a view showing a heated filter plate surface.
FIG. 9 is a diagram showing the surface of a non-heated filter plate.
FIG. 10 is an enlarged vertical cross-sectional view of a main part showing a cake discharging state.
FIG. 11 is an enlarged longitudinal sectional view of a main part of a filter press device according to a third embodiment.
FIG. 12 is an enlarged vertical cross-sectional view of a main part showing a cake discharging state.
FIG. 13 is an enlarged vertical sectional view showing a main part of a fourth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Filter press apparatus, 2 ... Heated filter board, 3 ... Non-heated filter board, 4 ... Filter cloth, r, R ... Ring-shaped seal part.

Claims (4)

A filter chamber formed between the filter plates, each having a pair of filter cloths in the filter chamber, and a sludge heating section for heating the sludge supplied into the filter chamber by heat exchange with the heat medium, A dehydrating and drying method using a filter press that supplies a heat medium to a sludge heating unit and vacuum-sucks a filter chamber to evaporate water in the sludge and performs dehydration and drying.
At least one of the peripheral edge of the filter plate and the peripheral edge of the filter cloth is provided with a continuous ring-shaped seal portion so as to surround the filter chamber,
While closely adhering the peripheral parts of the filter plate through the ring-shaped seal part,
The vacuum suction is performed from within the filter plate surface area surrounded by the ring-shaped seal portion,
The dehydration drying method using the filter press apparatus characterized by the above-mentioned. A filter chamber formed between the filter plates, each having a pair of filter cloths in the filter chamber, and a sludge heating section for heating the sludge supplied into the filter chamber by heat exchange with the heat medium, A filter press device configured to perform dehydration drying by supplying a heat medium to a sludge heating unit and vacuuming the filter chamber to evaporate water in the sludge,
At least one of the peripheral edge of the filter plate and the peripheral edge of the filter cloth is provided with a continuous ring-shaped seal portion so as to surround the filter chamber,
While configured so that the peripheral portions of the filter plates are in close contact with each other via the ring-shaped seal portion,
The vacuum suction is made from the inside of the filter plate surface area surrounded by the ring-shaped seal portion,
The filter press apparatus characterized by the above-mentioned. The ring-shaped seal portion is provided only at the peripheral portion of the filter plate, and the filter cloth is configured to be disposed only at least in a region surrounded by the ring-shaped seal portion at the time of vacuum suction, The filter press apparatus according to claim 2. The pressure air is supplied between the filter cloth and the filter plate, and the filter cloth is bulged with respect to the filter plate so that the cake attached to the filter cloth is peeled off. The filter press apparatus of Claim 1.

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