Relay control-based queuing unloading system for multiple filter presses

Abstract

The application relates to a relay control-based queuing unloading system of multiple filter presses. In order to overcome the defects of the prior art, the application comprises m filter presses, m scraper conveyors, a belt conveyor, a large centralized PLC, a total fire line and a total zero line, each filter press is additionally provided with a filter press PLC, each filter press PLC is provided with a corresponding scraper conveyor operation signal feedback connection line and a filter press starting signal output line, the two are respectively connected with a feedback relay coil and a filter press unloading starting normally open contact switch, each feedback relay coil, the normally open contact switch and a plurality of normally closed contact switches form a feedback relay switch, the filter press unloading starting normally open contact switch and a starting relay coil form a filter press unloading starting relay switch, m and n are positive integers, m>n>=2. The application has low transformation cost and reliable operation, and is suitable for low-cost upgrading and transformation of the existing filter press system.

Description

[0001] The present application relates to a kind of based on relay control's multiple filter press queuing unloading system. BACKGROUND

[0002] Filter press is applied to the automatic equipment of chemical industry, such as environmental protection, the role is to the slurry (such as coal slurry water) of certain concentration under certain pressure filtration realizes solid-liquid separation, solid forms filter cake and is unloaded, and filtrate is collected with special pipeline.

[0003] At present, many domestic factories and mines using multiple filter presses for sewage treatment, generally due to the conveying capacity of product conveyor or the limitation of next process link, multiple filter presses cannot unload at the same time, only unload one and then unload another or unload two at the same time, and then unload the other two one by one.

[0004] As shown in Figure 1 The existing filter press system includes coal slurry thickening bin 1, buffer bin 2, m stirring barrels 3, m filter presses 4, multiple scraper conveyors 5, belt conveyors 6, large centralized PLC (7), total fire line L, total zero line N, common negative terminal M and common positive terminal 99. The filter press 4 and the scraper conveyor 5 correspond to each other, and each filter press 4 is arranged above the corresponding scraper conveyor 5.

[0005] As shown in Figure 2 Each filter press 4 is also provided with a filter press PLC (8), and the large centralized PLC (7) is provided with a special input port I and a special output port O for each filter press PLC (8). Each filter press PLC (8) is provided with a first relay switch (KA1, KA2 … KAm), a scraper conveyor contactor (KM1, KM2 … KMm) and a second relay switch (KB1, KB2 … KBm). Each first relay switch (KA1, KA2 … KAm) includes a first relay coil and a first normally open contact switch. Each scraper conveyor contactor (KM1, KM2 … KMm) includes a contactor coil and a normally open auxiliary contact switch. Each second relay switch (KB1, KB2 … KBm) includes a second relay coil and a second normally open contact switch. Each first relay coil is connected in series between the corresponding filter press PLC (8) and the common negative terminal M. Each first normally open contact switch is connected in series between the total fire line L and the special input port I of the corresponding filter press PLC (8) of the large centralized PLC (7). Each contactor coil is connected in series between the total fire line L and the special output port O of the corresponding filter press PLC (8) of the large centralized PLC (7). Each normally open auxiliary contact switch is connected in series between the total fire line L and the total zero line N with the corresponding second relay coil. Each second normally open contact switch is connected in series between the total fire line L and the total zero line N.

[0006] As shown in Figure 2As shown, the filter press No. 4 needs to be unloaded, under the control of the filter press PLC (8), the first relay coil is powered, and the first normally open contact switch is closed. After the large set control PLC (7) receives the signal input through the corresponding special input port I, the corresponding contactor coil is powered through the corresponding special output port O, the normally open auxiliary contact switch is closed, the second relay coil is powered, and finally the second normally open contact switch is closed. The filter press PLC (8) controls the filter press No. 4 to automatically start the unloading program and automatically cycle the production operation.

[0007] The above structure can prevent the filter press 4 above the downstream scraper conveyor 5 from unloading when the scraper conveyor 5 does not run, effectively preventing unloading when the downstream scraper conveyor 5 does not run. However, if there are two or more filter presses 4 above the belt conveyor 6 simultaneously unloading, it is easy to cause the belt conveyor 6 to be overloaded for a short time, and the excess filter residue is easy to overflow the belt conveyor 6. However, the above structure cannot realize automatic queuing unloading.

[0008] If a special PLC-programmed cabinet with automatic queuing unloading function is used, the cost is as high as about 500,000 yuan, and the existing technology urgently needs a low-cost and reliable multi-filter press queuing unloading system based on relay control. SUMMARY

[0009] The technical problem to be solved by the present application is how to overcome the above-mentioned defects of the prior art and provide a low-cost multi-filter press queuing unloading system based on relay control.

[0010] To solve the above technical problems, the relay control-based multi-filter unloading system comprises a coal slurry thickening bin (1), a buffer bin (2), m stirring barrels (3), m filter presses (4), a plurality of scraper conveyors (5), a belt conveyor (6), a large centralized PLC (7), a total fire line (L), a total zero line (N), a common negative terminal (M), and a common positive terminal (99). The filter presses (4) and the scraper conveyors (5) correspond to each other, and each filter press (4) is arranged above the corresponding scraper conveyor (5). Each filter press (4) is also provided with a filter press PLC (8). The large centralized PLC (7) is provided with a dedicated input port (I) and a dedicated output port (O) for each filter press PLC (8). Each filter press PLC (8) is provided with a first relay switch (KA1, KA2, …, KAm), a scraper conveyor contactor (KM1, KM2, …, KMm), and a second relay switch (KB1, KB2, …, KBm). Each first relay switch (KA1, KA2, …, KAm) comprises a first relay coil and a first normally open contact switch. Each scraper conveyor contactor (KA1, KA2, …, KAm) comprises a contactor coil and a normally open auxiliary contact switch. Each second relay switch (KB1, KB2, …, KBm) comprises a second relay coil and a second normally open contact switch. Each first relay coil is connected in series between the corresponding filter press PLC (8) and the common negative terminal (M). Each first normally open contact switch is connected in series between the total fire line (L) and the dedicated input port (I) of the corresponding filter press PLC (8) on the large centralized PLC (7). Each contactor coil is connected in series between the total fire line (L) and the dedicated output port (O) of the corresponding filter press PLC (8) on the large centralized PLC (7). Each normally open auxiliary contact switch is connected in series between the total fire line (L) and the total zero line (N) with the corresponding second relay coil. The second normally open contact switch is connected in series between the total fire line (L) and the total zero line (N).

[0011] When a filter press needs to be unloaded, the first relay coil of the filter press PLC (8) is powered, and the first normally open contact switch is closed. After the large centralized PLC (7) receives the signal input through the corresponding dedicated input port (I), the corresponding contactor coil is powered through the corresponding dedicated output port (O), the normally open auxiliary contact switch is closed, the second relay coil is powered, and finally the second normally open contact switch is closed. The filter press PLC (8) receives the feedback from the scraper conveyor start, and the corresponding filter press automatically starts the unloading program and automatically cycles the production operation. The n filter presses (4) and their corresponding scraper conveyors (5) form a first group, and the remaining filter presses (4) and their corresponding scraper conveyors (5) form a second group.

[0012] The first group of each filter press PLC (8) is respectively provided with n-1 normally closed contact switches, the normally closed contact switches are respectively connected in series on the wires between the other filter press PLC (8) in the same group and the common negative terminal (M), the n-1 normally closed contact switches are controlled by the corresponding first relay coil, or are controlled by the first relay coil and the coil connected in parallel with the first relay coil;

[0013] The second group of each filter press PLC (8) is respectively provided with m-n-1 normally closed contact switches, the normally closed contact switches are respectively connected in series on the wires between the other filter press PLC (8) in the same group and the common negative terminal (M), the m-n-1 normally closed contact switches are controlled by the corresponding first relay coil, or are controlled by the corresponding first relay coil and the third relay coil connected in parallel with the first relay coil, the third relay coil is connected in parallel with the corresponding first relay coil, m and n are positive integers, m>n≥2.

[0014] In this way, at any same time, only one filter press in the same group is in unloading, so that at any time, at most two filter presses above the belt conveyor are simultaneously unloaded, effectively preventing the occurrence of short-term overload of the belt conveyor 6, reducing the occurrence of filter residue overflowing the belt of the belt conveyor 6, and the load fluctuation of the belt conveyor is small.

[0015] As an optimization, m=7, n=3, the two normally closed contact switches of the first group of each filter press PLC (8) form a third relay switch with the third relay coil;

[0016] One normally closed contact switch of the second group of each filter press PLC (8) is controlled by the corresponding first relay coil and forms a first relay switch with the first normally open contact switch, and the remaining two normally closed contact switches form a third relay switch with the third relay coil.

[0017] In this way, when the first relay coil and the third relay coil fail, they can be replaced individually, which is convenient to purchase and maintain.

[0018] The relay control-based multi-filter press queuing unloading system has low transformation cost and reliable operation, and is suitable for low-cost upgrading and transformation of existing filter press systems. BRIEF DESCRIPTION OF DRAWINGS

[0019] The relay control-based multi-filter press queuing unloading system will be further described below with reference to the accompanying drawings:

[0020] Figure 1 is a schematic diagram of the distribution process of the filter press system equipment;

[0021] Figure 2Is the circuit structure schematic diagram between the PLC of No.4 filter press and the main control PLC before the modification of the existing filter press system;

[0022] Figure 3 Is the local circuit structure diagram of the first group of the multi-filter press queuing and unloading system based on relay control (the first group contains No.3, No.4 and No.5 filter presses in Figure 1 );

[0023] Figure 4 Is the local circuit structure diagram of the second group of the multi-filter press queuing and unloading system based on relay control (the second group contains No.1, No.2, No.6 and No.7 filter presses in Figure 1 ).

[0024] In the figure: 1 is a coal slurry thickening bin, 2 is a buffer bin, 3 is a stirring barrel, 4 is a filter press, 5 is a scraper conveyor, 6 is a belt conveyor, 7 is a main control PLC, 8 is a filter press PLC, 9 is a coal slurry water feeding pipe, 10 is a filter press water drainage pipe;

[0025] L is the total fire line, N is the total zero line, M is the 24V common negative pole, M is the common negative pole end (24V), and 99 is the common positive pole end;

[0026] I is the special input port of each filter press PLC (8) on the main control PLC (7);

[0027] O is the special output port of each filter press PLC (8) on the main control PLC (7);

[0028] KA1, KA2, KA3, KA4, KA5, KA6, KA7 are the first relay switches corresponding to each filter press PLC (8);

[0029] KM1, KM2, KM3, KM4, KM5, KM6, KM7 are the scraper machine contactors corresponding to each filter press PLC (8);

[0030] KB1, KB2, KB3, KB4, KB5, KB6, KB7 are the second relay switches corresponding to each filter press PLC (8);

[0031] KC1, KC2, KC3, KC4, KC5, KC6, KC7 are the third relay switches corresponding to each filter press PLC (8). DETAILED DESCRIPTION

[0032] Embodiment one: as Figure 1 , 3,4, the present application based on relay control of multiple filter press unloading system includes coal slurry thickening bin 1, buffer bin 2, m stirring barrel 3, m filter press 4, a plurality of scraper conveyor 5, belt conveyor 6, large centralized PLC (7), the total fire line L, the total zero line N, the common negative terminal M and the common positive terminal 99, the filter press 4, the scraper conveyor 5 one by one, each filter press 4 is arranged above the corresponding scraper conveyor 5, each filter press 4 is also equipped with a filter press PLC (8), the large centralized PLC (7) is provided with special input port I and special output port O for each filter press PLC (8), each filter press PLC (8) is equipped with first relay switch KA1, KA2... KAm (when m is 7, KA7), scraper machine contactor KM1, KM2... KMm (when m is 7, KM7) and second relay switch KB1, KB2... KBm (when m is 7, KB7), each first relay switch KA1, KA2... KAm includes a first relay coil and a first normally open contact switch, each scraper machine contactor KM1, KM2... KMm includes a contactor coil and a normally open auxiliary contact switch, each second relay switch KB1, KB2... KBm includes a second relay coil and a second normally open contact switch, each first relay coil is respectively connected in series between the corresponding filter press PLC (8) and the common negative terminal M, each first normally open contact switch is respectively connected in series between the total fire line L and the special input port I of the corresponding filter press PLC (8) on the large centralized PLC (7), each contactor coil is respectively connected in series between the total fire line L and the special output port O of the corresponding filter press PLC (8) on the large centralized PLC (7), each normally open auxiliary contact switch is respectively connected in series between the total fire line L and the total zero line N with the corresponding second relay coil, each second normally open contact switch is respectively connected in series between the total fire line L and the total zero line N, characterized in that: n filter presses 4 and their corresponding scraper conveyors 5 form a first group, the rest of the filter presses 4 and their corresponding scraper conveyors 5 form a second group,

[0033] Each filter press PLC (8) in the first group is respectively provided with n-1 normally closed contact switches, the above normally closed contact switches are respectively connected in series on the wire between the other filter press PLC (8) in the same group and the common negative terminal M, the above n-1 normally closed contact switches are controlled by the corresponding first relay coil, or by the first relay coil and the coil connected in parallel with the first relay coil;

[0034] Each filter press PLC (8) in the second group is equipped with mn-1 normally closed contact switches. The normally closed contact switches are connected in series to the wires between the other filter press PLCs (8) in the same group and the common negative terminal M. The mn-1 normally closed contact switches are all controlled by the corresponding first relay coil, or by the corresponding first relay coil and the third relay coil. The third relay coil is connected in parallel with the corresponding first relay coil. m and n are both positive integers, and m > n ≥ 2.

[0035] The first relay switches KA1, KA2...KAm and the third relay switches KC1, KC2...KCm are preferred; Schneider RXM2AB2BD 24V is preferred.

[0036] Figure 1 , 3 In the specific implementation shown in section 4, m = 7 and n = 3. The first group includes... Figure 1 In the No. 3, No. 4 and No. 5 filter presses, the two normally closed contact switches of each filter press PLC (8) in the first group are combined with the third relay coil to form the third relay switch KC3, KC4 and KC5;

[0037] The second group includes Figure 1 In the filter presses No. 1, No. 2, No. 6 and No. 7, the normally closed contact switch of each filter press PLC (8) in the second group is controlled by the corresponding first relay coil, and together with the first normally open contact switch, they form the first relay switch.

[0038] The remaining two normally closed contact switches are combined with the third relay coil to form the third relay switches KC1, KC2, KC6, and KC7.

[0039] Working principle: Assuming that filter press No. 4 needs to unload, under the control of its filter press PLC (8), its first relay coil is energized, and then the first normally open contact switch is closed. After the large centralized control PLC (7) receives the signal input from the corresponding dedicated input port I, it energizes the corresponding contactor coil through the corresponding dedicated output port O, causing the normally open auxiliary contact switch to close, energizing the second relay coil, and finally closing the second normally open contact switch. The filter press PLC (8) receives the feedback signal of the scraper conveyor starting, and filter press No. 4 automatically starts the unloading program and automatically cycles through production.

[0040] When filter press No. 4 automatically begins the unloading process, its third relay coil KC4 is energized. The two normally closed contact switches connected in series between the PLC (8) of filter presses No. 3 and No. 5 in the same group and the common negative terminal M are kept in the open state. In this way, filter presses No. 3 and No. 5 do not receive a feedback signal and cannot execute the unloading procedure, and are in a queuing waiting state.

[0041] Once the 4th filter press unloading is completed, because the filter press PLC (8) program can switch to continuous operation state, the 4th filter press automatically enters the next cycle program. The third relay coil KC4 loses power, the two normally closed contacts of KC4 are closed, and the filter press PLC (8) of the 3rd and 5th filter presses returns to the unloading state, and of course the 3rd and 5th filter presses also automatically execute the queuing unloading.

[0042] Similarly, the 1st, 2nd, 6th and 7th filter presses in the second group also automatically execute the queuing unloading

[0043] This scheme adds several relay switches on the basis of the existing filter press system large centralized PLC (7) and each filter press PLC (8), with a small cost, each filter press can automatically queue and unload, and the function is more in line with the actual needs of the scene, not mechanical queuing and unloading, but which filter press has high efficiency and is automatically unloaded first, and then automatically queued. If a single filter press fails, it will automatically exit the queuing unloading. The feeding, filtering and transportation equipment are automatically connected and operated, and no full-time operators are needed on site. It can greatly improve the production efficiency of the filter press and eliminate human errors. This technology has great application value for factories and mines using multiple filter presses.

Claims

1. A relay control-based queuing unloading system for multiple filter presses, comprising a coal slurry thickening bin (1), a buffer bin (2), m stirring barrels (3), m filter presses (4), a plurality of scraper conveyors (5), a belt conveyor (6), a large centralized PLC (7), a total fire line (L), a total zero line (N), a common negative terminal (M), and a common positive terminal (99), the filter presses (4) and the scraper conveyors (5) corresponding one-to-one, each filter press (4) being arranged above the corresponding scraper conveyor (5), and each filter press (4) being further provided with a filter press PLC (8), the large centralized PLC (7) being provided with a dedicated input port (I) and a dedicated output port (O) for each filter press PLC (8), each filter press PLC (8) being provided with a first relay switch (KA1, KA2, …, KAm), a scraper machine contactor (KM1, KM2, …, KMm), and a second relay switch (KB1, KB2, …, KBm), each first relay switch (KA1, KA2, …, KAm) comprising a first relay coil and a first normally open contact switch, each scraper machine contactor (KM1, KM2, …, KMm) comprising a contactor coil and a normally open auxiliary contact switch, and each second relay switch (KB1, KB2, …, KBm) comprising a second relay coil and a second normally open contact switch, each first relay coil being connected in series between the corresponding filter press PLC (8) and the common negative terminal (M), each first normally open contact switch being connected in series between the total fire line (L) and the dedicated input port (I) of the corresponding filter press PLC (8) on the large centralized PLC (7), each contactor coil being connected in series between the total fire line (L) and the dedicated output port (O) of the corresponding filter press PLC (8) on the large centralized PLC (7), each normally open auxiliary contact switch being connected in series with the corresponding second relay coil between the total fire line (L) and the total zero line (N), and each second normally open contact switch being connected in series between the total fire line (L) and the total zero line (N), characterized in that: n filter presses (4) and their corresponding scraper conveyors (5) form a first group, and the rest of the filter presses (4) and their corresponding scraper conveyors (5) form a second group, Each filter press PLC (8) in the first group is respectively provided with n-1 normally closed contact switches, which are respectively connected in series with the wires between the other filter press PLC (8) in the same group and the common negative terminal (M), and the n-1 normally closed contact switches are controlled by the corresponding first relay coil, or by the first relay coil and the coil connected in parallel with the first relay coil; Each filter press PLC (8) in the second group is respectively provided with m-n-1 normally closed contact switches, which are respectively connected in series with the wires between the other filter press PLC (8) in the same group and the common negative terminal (M), and the m-n-1 normally closed contact switches are controlled by the corresponding first relay coil, or by the corresponding first relay coil and the third relay coil connected in parallel with the corresponding first relay coil, m and n are both positive integers, and m>n≥2.

2. The relay control based multi-filter discharge queuing system of claim 1, wherein: m=7, n=3, the two normally closed contact switches of each filter press PLC (8) in the first group form a third relay switch with the third relay coil; One normally closed contact switch of each filter press PLC (8) in the second group is controlled by the corresponding first relay coil and forms a first relay switch with the first normally open contact switch, and the remaining two normally closed contact switches form a third relay switch with the third relay coil.

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