Stable operation of a pulp washing device and control method

Abstract

The present application relates to the technical field of pulp washing, and particularly relates to a stable operation pulp washing device and a control method, which comprises a press extruding pulp machine, a flow controller arranged at the feeding end of each press extruding pulp machine, and a stand pipe arranged at the discharging end of each press extruding pulp machine; the press extruding pulp machine, the flow controller and the stand pipe constitute a washing mechanism; a liquid level sensor, a pulp discharging port and a dilution water inlet are arranged on the stand pipe, the liquid level sensor is in communication connection with the flow controller, the pulp discharging port is connected with the feeding end of the press extruding pulp machine of another washing mechanism in a pipeline to form a series connection between the washing mechanisms, and a plurality of washing mechanisms are connected in a pipeline to form a pulp washing path. The present application can balance the liquid level in the stand pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pulp washing, in particular to a stable operation pulp washing device and control method. BACKGROUND

[0002] Pulp is an important raw material for papermaking, in order to ensure the manufacturing quality of the production, it is necessary to wash the pulp, separate and extract the black liquor in the pulp. The current pulp washing is usually through the washing machine to separate and extract the black liquor in the pulp, and then dilute with water, and so on. Because the volume of the standpipe used for diluting the pulp is limited, the liquid level in the standpipe is easy to produce large fluctuation, and then easy to cause equipment failure shutdown. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a stable operation pulp washing device and control method, which can balance the liquid level in the standpipe.

[0004] In order to solve the above technical problem, the technical scheme adopted by the present application is as follows: a stable operation pulp washing device, comprising a press extruding pulp machine, a flow controller arranged at the inlet end of each press extruding pulp machine, and a standpipe arranged at the outlet end of each press extruding pulp machine; the press extruding pulp machine, the flow controller and the standpipe constitute a washing mechanism.

[0005] A liquid level sensor, a pulp discharge port and a dilution water inlet are arranged on the standpipe, the liquid level sensor is in communication connection with the flow controller, the pulp discharge port is connected with the inlet end of the press extruding pulp machine of another washing mechanism in pipeline to form a series connection between the washing mechanisms, and a plurality of washing mechanisms are connected in pipeline to form a pulp washing path.

[0006] In order to solve the above technical problem, the present application provides a control method based on the stable operation pulp washing device in the above scheme, which is as follows:

[0007] The method comprises the following steps: S1, setting a standard pulp liquid level value in the standpipe;

[0008] S2, conveying the pulp to be washed into the press extruding pulp machine for pressing along the pulp washing path, and conveying into the standpipe for dilution;

[0009] If the pulp liquid level in the inner cavity of the standpipe in step S2 is as follows:

[0010] When the actual pulp liquid level in the inner cavity of the standpipe is higher than the standard pulp liquid level value, the flow controller increases the pulp flow into the press extruding pulp machine;

[0011] When the actual pulp liquid level in the inner cavity of the standpipe is lower than the standard pulp liquid level value, the flow controller reduces the pulp flow into the press extruding pulp machine.

[0012] The beneficial effect of the present application is that a flow controller is added at the feeding end of the press expeller, a liquid level sensor is added on the standpipe, and the liquid level sensor is in communication connection with the flow controller. By setting a standard liquid level value of the pulp, in the process of washing the pulp, dilution water enters the standpipe through the dilution water inlet to dilute the pulp concentration pressed by the press expeller, when the liquid level sensor judges that the actual liquid level of the pulp in the inner cavity of the standpipe is higher than the standard liquid level value of the pulp, that is, the flow of the pulp into the standpipe is insufficient, at this time the flow controller increases the flow of the pulp into the press expeller to increase the flow of the pulp discharged from the discharge end of the press expeller, thereby increasing the pressure in the standpipe, so that the diluted pulp can be quickly discharged; when the liquid level sensor judges that the actual liquid level of the pulp in the inner cavity of the standpipe is lower than the standard liquid level value of the pulp, that is, the flow of the pulp into the standpipe is too large, at this time the flow controller reduces the flow of the pulp into the press expeller to reduce the flow of the pulp discharged from the discharge end of the press expeller, thereby reducing the pressure in the standpipe, so that the speed of the diluted pulp discharged from the standpipe is slowed down. Thus, the liquid level balance in the standpipe is effectively and stably controlled. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A system structure schematic diagram for stably operating a pulp washing device in the specific embodiment of the present application;

[0014] Label explanation:

[0015] 1. Press expeller;

[0016] 2. Flow controller; 21. Pulp inlet valve; 22. Medium concentration pump;

[0017] 3. Standpipe. DETAILED DESCRIPTION

[0018] To explain the technical content, purposes and effects of the present application in detail, the following will be explained in combination with the embodiments and the drawings.

[0019] Pulp is an important raw material for papermaking. In order to ensure the manufacturing quality of the production, the pulp needs to be washed to separate and extract the black liquor in the pulp. The current pulp washing is usually to separate and extract the black liquor in the pulp by a washing machine, and then to dilute with water, and to repeat this cycle. Due to the limited volume of the standpipe for diluting the pulp, the liquid level in the standpipe is prone to have large fluctuations, which in turn easily causes equipment failure and shutdown.

[0020] Based on this, the present application provides a stable pulp washing device and control method, which can solve the problem of large fluctuations in the liquid level in the standpipe.

[0021] Please refer to Figure 1As shown in the drawings, the stable pulp washing device comprises a press squeezing machine 1, a flow controller 2 arranged at the feeding end of each press squeezing machine 1, and a vertical pipe 3 arranged at the discharging end of each press squeezing machine 1; the press squeezing machine 1, the flow controller 2 and the vertical pipe 3 constitute a washing mechanism.

[0022] The vertical pipe 3 is provided with a liquid level sensor, a pulp discharging port and a dilution water inlet, the liquid level sensor is in communication connection with the flow controller 2, the pulp discharging port is in pipeline connection with the feeding end of the press squeezing machine 1 of another washing mechanism to form a series connection between the washing mechanisms, and a plurality of washing mechanisms are in pipeline series connection to constitute a pulp washing path.

[0023] Preferably, five washing mechanisms are in pipeline series connection.

[0024] As can be seen from the above description, the beneficial effects of the present application are that the flow controller 2 is additionally arranged at the feeding end of the press squeezing machine 1, the liquid level sensor is additionally arranged on the vertical pipe 3, and the liquid level sensor is in communication connection with the flow controller 2. By setting a standard pulp liquid level value, in the process of washing the pulp, the dilution water enters the vertical pipe 3 through the dilution water inlet to dilute the pulp concentration pressed by the press squeezing machine 1; when the liquid level sensor judges that the actual pulp liquid level in the inner cavity of the vertical pipe 3 is higher than the standard pulp liquid level value, that is, the pulp flow entering the vertical pipe 3 is insufficient, at this time, the flow controller 2 increases the pulp flow entering the press squeezing machine 1 to increase the pulp flow discharged from the discharging end of the press squeezing machine 1, thereby increasing the pressure in the vertical pipe 3, so that the diluted pulp can be quickly discharged; when the liquid level sensor judges that the actual pulp liquid level in the inner cavity of the vertical pipe 3 is lower than the standard pulp liquid level value, that is, the pulp flow entering the vertical pipe 3 is too large, at this time, the flow controller 2 reduces the pulp flow entering the press squeezing machine 1 to reduce the pulp flow discharged from the discharging end of the press squeezing machine 1, thereby reducing the pressure in the vertical pipe 3, so that the speed of discharging the diluted pulp from the vertical pipe is slowed down. Thus, the liquid level balance in the vertical pipe 3 is effectively and stably controlled.

[0025] Please refer to Figure 1 As shown in the drawings, further, the flow controller 2 comprises a pulp inlet valve 21, and the pulp inlet valve 21 is in communication connection with the liquid level sensor.

[0026] As can be seen from the above description, the pulp flow entering the press squeezing machine 1 is controlled by controlling the opening size of the pulp inlet valve 21.

[0027] Please refer to Figure 1 As shown in the drawings, further, the flow controller 2 further comprises a medium-concentration pump 22, and the medium-concentration pump 22 is in communication connection with the liquid level sensor.

[0028] From the above description, the medium consistency pump 22 not only can provide the power of the pulp into the press expeller 1, but also can increase the pulp flow into the press expeller 1 by increasing the output power when the pulp valve 21 reaches the maximum opening and further increase the pulp flow into the press expeller 1 is needed.

[0029] Further, the press expeller 1 is provided with a pressure gauge for measuring the internal pressure of the press chamber of the press expeller 1, and the pressure gauge is in communication connection with the press expeller 1.

[0030] From the above description, in order to avoid the equipment failure shutdown caused by the high internal pressure of the press chamber of the press expeller 1, the pressure gauge is used for real-time monitoring. When the pressure gauge judges that the internal pressure of the press chamber of the press expeller 1 is higher than the standard value of the internal pressure of the press chamber, the output power of the press expeller 1 is increased to quickly discharge the pulp in the press chamber; when the pressure gauge judges that the internal pressure of the press chamber of the press expeller 1 is lower than the standard value of the internal pressure of the press chamber, the output power of the press expeller 1 is reduced to slow down the discharge rate of the pulp from the press chamber.

[0031] The control method of the present application comprises the following steps: S1, setting a standard pulp level value in the standpipe 3;

[0032] S2, conveying the pulp to be washed into the press expeller 1 along the pulp washing path for pressing, and into the standpipe 3 for dilution;

[0033] If the following situations exist in the inner cavity of the standpipe 3 in step S2:

[0034] When the actual pulp level in the inner cavity of the standpipe 3 is higher than the standard pulp level value, the flow controller 2 increases the pulp flow into the press expeller 1;

[0035] When the actual pulp level in the inner cavity of the standpipe 3 is lower than the standard pulp level value, the flow controller 2 reduces the pulp flow into the press expeller 1.

[0036] In the first alternative embodiment, in order to control the internal pressure balance of the press chamber of the press expeller 1, the following steps are taken: S2, setting a standard internal pressure value of the press chamber of the press expeller 1;

[0037] If the following situations exist in the internal pressure of the press chamber of the press expeller 1 in step S2:

[0038] When the internal pressure of the press chamber of the press expeller 1 is higher than the standard internal pressure value of the press chamber, the output power of the press expeller 1 is increased;

[0039] When the inside pressure of the press chamber of the press expeller 1 is lower than the inside pressure standard value of the press chamber, the output power of the press expeller 1 is reduced.

[0040] In the second optional embodiment, in order to control the inside pressure balance of the press chamber of the press expeller 1, the inside pressure standard value of the press chamber of the press expeller 1 is set in step S2.

[0041] When the inside pressure of the press chamber of the press expeller 1 is higher than the inside pressure standard value of the press chamber, the output power of the press expeller 1 is increased and the concentration of the pulp to be washed into the inside of the press chamber of the press expeller 1 is reduced.

[0042] When the inside pressure of the press chamber of the press expeller 1 is lower than the inside pressure standard value of the press chamber, the output power of the press expeller 1 is reduced and the concentration of the pulp to be washed into the inside of the press chamber of the press expeller 1 is increased.

[0043] When the inside pressure of the press chamber of the press expeller 1 is lower than the inside pressure standard value of the press chamber, the output power of the press expeller 1 is reduced and the concentration of the pulp to be washed into the inside of the press chamber of the press expeller 1 is increased.

[0044] In the third optional embodiment, in order to control the inside pressure balance of the press chamber of the press expeller 1, the inside pressure standard value of the press chamber of the press expeller 1 is set in step S2.

[0045] When the inside pressure of the press chamber of the press expeller 1 is higher than the inside pressure standard value of the press chamber, the output power of the press expeller 1 is increased and the concentration of the pulp to be washed into the inside of the press chamber of the press expeller 1 is reduced.

[0046] When the inside pressure of the press chamber of the press expeller 1 is lower than the inside pressure standard value of the press chamber, the output power of the press expeller 1 is reduced and the concentration of the pulp to be washed into the inside of the press chamber of the press expeller 1 is increased.

[0047] When the inside pressure of the press chamber of the press expeller 1 is lower than the inside pressure standard value of the press chamber, the output power of the press expeller 1 is reduced and the concentration of the pulp to be washed into the inside of the press chamber of the press expeller 1 is increased.

[0048] In the above-mentioned first to third optional embodiments, the inside pressure standard value of the press chamber of the press expeller 1 is 9kpa to 11kpa. Preferably, the inside pressure standard value of the press chamber of the press expeller 1 is 9kpa, 10kpa or 11kpa, and most preferably, the inside pressure standard value of the press chamber of the press expeller 1 is 10kpa.

[0049] Example 1

[0050] A stable pulp washing device, please refer to Figure 1As shown, it comprises a pressurized pulp press 1, a flow controller 2 arranged at the inlet end of each pressurized pulp press 1, and a standpipe 3 arranged at the outlet end of each pressurized pulp press 1; the pressurized pulp press 1, the flow controller 2, and the standpipe 3 constitute a washing mechanism; the standpipe 3 is provided with a liquid level sensor, a pulp discharge port, and a dilution water inlet; the liquid level sensor is in communication with the flow controller 2; the pulp discharge port is connected to the inlet end of the pressurized pulp press 1 of another washing mechanism to form a series connection between the washing mechanisms; a plurality of washing mechanisms are connected in series to form a pulp washing path.

[0051] Embodiment II

[0052] A control method comprises the following steps: S1, setting a standard pulp liquid level value in the standpipe 3; S2, conveying the pulp to be washed into the pressurized pulp press 1 for pressing and into the standpipe 3 for dilution; if the pulp liquid level in the inner cavity of the standpipe 3 in step S2 meets the following conditions: the actual pulp liquid level in the inner cavity of the standpipe 3 is higher than the standard pulp liquid level value, the flow controller 2 increases the pulp flow into the pressurized pulp press 1; the actual pulp liquid level in the inner cavity of the standpipe 3 is lower than the standard pulp liquid level value, the flow controller 2 reduces the pulp flow into the pressurized pulp press 1.

[0053] Embodiment III

[0054] This embodiment further limits how to control the pressure balance in the pressurized pulp press 1 based on Embodiment II, and the specific implementation is as follows:

[0055] In step S2, a standard pressure value in the pressurized pulp press 1 is set; if the pressure in the pressurized pulp press 1 in step S2 meets the following conditions: the pressure in the pressurized pulp press 1 is higher than the standard pressure value, the output power of the pressurized pulp press 1 is increased; the pressure in the pressurized pulp press 1 is lower than the standard pressure value, the output power of the pressurized pulp press 1 is reduced. The standard pressure value in the pressurized pulp press 1 is 10 kPa.

[0056] Embodiment IV

[0057] This embodiment further limits how to control the pressure balance in the pressurized pulp press 1 based on Embodiment II, and the specific implementation is as follows:

[0058] In step S2, the inside pressure standard value of the press chamber of the press expeller 1 is set. If the inside pressure of the press chamber of the press expeller 1 in step S2 is higher than the inside pressure standard value, the concentration of the pulp to be washed delivered into the inside of the press chamber of the press expeller 1 is lowered. If the inside pressure of the press chamber of the press expeller 1 in step S2 is lower than the inside pressure standard value, the concentration of the pulp to be washed delivered into the inside of the press chamber of the press expeller 1 is increased. The inside pressure standard value of the press chamber of the press expeller 1 is 10 kPa.

[0059] Example Five

[0060] This embodiment further defines how to control the inside pressure balance of the press chamber of the press expeller 1 on the basis of Example Two, as follows:

[0061] In step S2, the inside pressure standard value of the press chamber of the press expeller 1 is set. If the inside pressure of the press chamber of the press expeller 1 in step S2 is higher than the inside pressure standard value, the output power of the press expeller 1 is increased and the concentration of the pulp to be washed delivered into the inside of the press chamber of the press expeller 1 is lowered. If the inside pressure of the press chamber of the press expeller 1 in step S2 is lower than the inside pressure standard value, the output power of the press expeller 1 is decreased and the concentration of the pulp to be washed delivered into the inside of the press chamber of the press expeller 1 is increased. The inside pressure standard value of the press chamber of the press expeller 1 is 10 kPa.

[0062] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent transformation or direct or indirect application in the related technical field based on the content of the present application specification and drawings is also included in the patent protection scope of the present application.

Claims

1. A control method for stabilizing the operation of a pulp washing device, characterized by: The stable operation pulp washing device comprises a press expeller, a flow controller arranged at the feeding end of each press expeller, and a standpipe arranged at the discharging end of each press expeller; the press expeller, the flow controller, and the standpipe constitute a washing mechanism; A liquid level sensor, a pulp discharging port, and a dilution water inlet are arranged on the standpipe; the liquid level sensor is in communication connection with the flow controller; the pulp discharging port is connected with the feeding end of another press expeller of the washing mechanism in series to form a series connection between the washing mechanisms; a plurality of the washing mechanisms are connected in series to form a pulp washing path; In step S1, a standard pulp liquid level value is set in the standpipe; In step S2, the pulp to be washed is delivered into the press expeller along the pulp washing path to be pressed, and into the standpipe to be diluted; If the pulp liquid level in the inner cavity of the standpipe in step S2 is as follows: If the actual pulp liquid level in the inner cavity of the standpipe is higher than the standard pulp liquid level value, the flow controller increases the pulp flow into the press expeller; If the actual pulp liquid level in the inner cavity of the standpipe is lower than the standard pulp liquid level value, the flow controller decreases the pulp flow into the press expeller.

2. The control method according to claim 1, characterized in that: The flow controller comprises a pulp inlet valve in communication connection with the liquid level sensor.

3. The control method according to claim 2, characterized in that: The flow controller further comprises a medium consistency pump in communication connection with the liquid level sensor.

4. The control method according to claim 1 or 3, characterized by: A pressure gauge for measuring the pressure in the press chamber of the press expeller is arranged on the press expeller; the pressure gauge is in communication connection with the press expeller.

5. The control method of claim 1, wherein: In step S2, a standard pressure value in the press chamber of the press expeller is set; If the pressure in the press chamber of the press expeller in step S2 is as follows: If the pressure in the press chamber of the press expeller is higher than the standard pressure value, the output power of the press expeller is increased; If the pressure in the press chamber of the press expeller is lower than the standard pressure value, the output power of the press expeller is decreased.

6. The control method of claim 1, wherein: In step S2, a standard pressure value in the press chamber of the press expeller is set; If the pressure in the press chamber of the press expeller in step S2 is as follows: If the pressure in the press chamber of the press expeller is higher than the standard pressure value, the concentration of the pulp to be washed delivered into the press chamber of the press expeller is decreased; If the pressure in the press chamber of the press expeller is lower than the standard pressure value, the concentration of the pulp to be washed delivered into the press chamber of the press expeller is increased.

7. The control method of claim 1, wherein: In step S2, a standard pressure value in the press chamber of the press expeller is set; If the pressure in the press chamber of the press expeller in step S2 is as follows: If the pressure in the press chamber of the press expeller is higher than the standard pressure value, the output power of the press expeller is increased and the concentration of the pulp to be washed delivered into the press chamber of the press expeller is decreased; When the inside pressure of the pressurized chamber of the pressurized pulper is lower than the inside pressure standard value of the pressurized chamber, the output power of the pressurized pulper is reduced and the concentration of the pulp to be washed, which is delivered into the inside of the pressurized chamber of the pressurized pulper, is increased.

8. The control method of claim 5, wherein: The inside pressure standard value of the pressurized chamber of the pressurized pulper is 9 kPa to 11 kPa.

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