JPH0133131Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a residual liquid return device for a filter press.

For filter presses that perform batch-type filtration operations, the stock solution remaining in the stock solution supply circuit must be returned to the stock solution tank after each filtration process is completed. When opened, residual liquid falls onto the cake tray. Therefore, the filter press is connected to a compressed air supply circuit in which a check valve, an on-off valve, etc. are inserted at the final end of the stock solution supply circuit to the filtration chamber, and the compressed air supply circuit is inserted at a position close to the filter press. A certain check valve prevents the stock solution from flowing in the opening/closing direction of this circuit during filtration operation, and when the filtration operation is completed, the opening/closing valve is opened each time to send compressed air into the stock solution supply circuit of the filter press. This pushes the remaining liquid back toward the stock solution tank.

However, in this type of residual liquid return device, if a problem occurs with the check valve, which is generally considered a consumable item, it can easily stop when the liquid is being pressurized into the filter press.
The concentrate will not only leak into the compressed air supply circuit, which will then become contaminated with the concentrate, but also, in the case of filter presses integrated in chemical processes, Leakage may cause corrosion of the circuit, leading to serious accidents. Of course, if only to prevent corrosion of the circuits due to leakage of raw solution, these circuits, air tanks, etc. could all be constructed of high-grade materials such as stainless steel, but this would be too costly. Therefore, this idea was proposed, and its gist is that a leakage liquid reservoir is created at a suitable place in the circuit on the primary side of the check valve of the above-mentioned residual liquid return device, where leakage liquid into the circuit can accumulate. A liquid leakage detection device is inserted in which a pair of electrode rods are placed opposite each other in the liquid reservoir, and an alarm current flows between the pair of electrodes when leakage liquid accumulates in the leakage liquid reservoir. .

To explain the embodiment with reference to figures, in FIG. 1, reference numeral 1 denotes a stock solution supply port to a filter press 2, and this stock solution supply port 1 includes a stock solution injection circuit 3 that communicates with a stock solution injection pump (not shown), and a stock solution injection circuit 3 that communicates with a stock solution injection pump (not shown). A return circuit 4 leading to a tank (not shown) is connected. 5
is a supply port for compressed air to the filter press 2, and this supply port 5 is connected to the final end of a supply circuit 6 for supplying stock solution to the filtration chamber in this filter press 2; A compressed air supply circuit 8 leading to the air tank 7 is connected thereto. 9 is an air compressor.

Then, the stock liquid press-in circuit 3 and the residual liquid return circuit 4
Air-operated on-off valves 10 and 11 are inserted into the compressed air supply circuit 8, respectively.
An air-operated on-off valve 13, a flow control valve 14, and a check valve 15 that stops the flow toward the air tank 7 are inserted, and each air-operated on-off valve 10, 1
When 1 and 13 are opened and closed in a predetermined order, the injection of raw liquid into the filter press 2 and the return of the remaining liquid from the filter press 2 are performed alternately. The following liquid leak detection device 1 is installed in the circuit on the primary side of the check valve 15 of the compressed air supply circuit 8 according to
6 has been inserted.

That is, the liquid leakage detection device 16 of this embodiment
As shown in FIGS. 2 and 3, a housing 17 is provided which is connected to the primary side 15a of the check valve 15 and inserted into the circuit 8.
A leaking liquid reservoir 18 is formed inside the housing 17 in which the leaking liquid leaking from the check valve 15 can first accumulate, and in this housing 17, when the leaking liquid is not collected in the leaking liquid reservoir 18, the leaking liquid reservoir 18 is mutually opened. A pair of electrode rods 19, which are a pair of electrode rods that are connected to each other, and when a certain amount of leakage liquid (up to the position in Figs. 2 and 3) collects in this leakage liquid reservoir 18, the end portions of the electrode rods 19 are closed by the accumulated leakage liquid. . A warning lamp 21 and/or a buzzer 22 of a warning circuit 20 warns of the occurrence of trouble. In addition, in FIGS. 2 and 3, 23 is an electrode cover.

Next, to explain the operation, in the compressed air supply circuit 8 of the residual liquid return device for a filter press according to this invention, a liquid leak detection device 16 as described above is inserted on the primary side of the check valve 15. Therefore, if an unexpected problem occurs with the check valve 15 and the raw liquid leaks to the primary side of the check valve 15 when the raw liquid is pressurized into the filter press 2, the leaked liquid will be Since the leaking liquid accumulates in the leaking liquid reservoir 18 first, the leaking liquid accumulates in the leaking liquid reservoir 1.
The positions of the pair of electrode rods 19, 19 in the housing 17 are set so that the space between the pair of electrode rods 19, 19 is closed by the leaked liquid before the leaked liquid accumulated in the electrode 8 does not flow out from there. By doing so, liquid leakage due to trouble in the check valve 15 can be immediately detected by a signal issued from the alarm circuit 20 into which the pair of electrode rods are inserted.

Therefore, according to the residual liquid return device for a filter press according to this invention, the residual liquid return circuit is configured by the above-mentioned liquid leak detection device inserted into the circuit on the primary side of the check valve. We quickly detect troubles and wear and tear that are likely to occur in check valves,
It is possible to prevent the accidents mentioned at the beginning, and even if the residual liquid return circuit and the air tank and compressor connected to it are constructed from low-grade materials at low cost, these structures This provides the advantage that there is no risk of the components being corroded by leaking liquid.

[Brief explanation of drawings]

Figure 1 is a flow sheet showing an embodiment of the residual liquid return device for a filter press according to this invention;
The figure is a partially cutaway side view of the liquid leak detection device, and FIG. 3 is a sectional view taken along the line -- in FIG. 2. 1...Stock solution supply port, 2...Filter press, 3
...Standard solution press-in circuit, 6 ...Standard solution supply circuit, 7...
Air tank, 8... Compressed air supply circuit, 9...
...Air compressor, 15...Check valve, 16
...Liquid leak detection device, 17...Housing, 18
...Leaking liquid pool, 19...Electrode rod, 20...Alarm circuit.

Claims (1)

[Claims for Utility Model Registration] 1. A compressed air supply circuit in which a check valve is inserted is connected to the final end of the stock solution supply circuit to the filtration chamber of the filter press, and the circuit on the primary side of the check valve is A residual liquid return device for a filter press that is connected to a supply source of compressed air, which forms a leakage liquid reservoir at a suitable place in the circuit on the primary side of the check valve, where leakage liquid into the circuit can accumulate. A liquid leakage detection device is inserted in the liquid reservoir, in which a pair of electrode rods are arranged opposite each other, and when leakage liquid accumulates in the leakage liquid reservoir, an alarm current flows between the pair of electrodes. What will become. 2. The residual liquid return device for a filter press according to claim 1, wherein the liquid leakage detection device is inserted into the circuit on the primary side of the check valve in contact with the primary side of the check valve. .