Pressure-stabilizing sizing device of toilet paper machine

Abstract

The invention discloses a toilet paper machine pressure-stabilizing sizing device which is characterized by comprising a pulp forming pool used for stirring and mixing long fibers and short fibers, a sizing pump, a basis weight valve and a control system, the input end of the sizing pump is communicated with the pulp forming pool, and the output end of the sizing pump is communicated with the input end of the basis weight valve through a sizing pipeline; the sizing pipeline is provided with a concentration meter and a pressure meter, the pressure meter is used for detecting the pipeline pressure in the sizing pipeline, the sizing pump adopts a variable frequency motor, and the control system controls the rotating speed of the variable frequency motor according to the pipeline pressure measured by the pressure meter. Shutdown caused by faults due to full-load operation of the motor is reduced, and the maintenance cost is reduced. And the lift of the pipeline is reduced from 15m to 6m, so that the lift of the pipeline and the energy waste caused by the backflow of the slurry to the slurry forming pool are reduced. The slurry stabilizing box mounting space and a backflow control valve are saved, and the system structure is simplified. And abnormal shutdown time loss caused by paper breakage due to the fact that pulp accumulation blocks on the top and the box wall of the pulp stabilizing box block a basis weight valve and influence pulp flow fluctuation is reduced.

Description

Technical Field

[0001] The invention relates to papermaking process equipment, in particular to a pressure-stabilizing sizing device for a toilet paper machine. Background Art

[0002] The papermaking process of the tissue paper machine is to send the pulp to the head box through the sizing system. The pulp is sprayed out through the head box and formed and separated by the felt cloth and the forming wire. Then, the paper is taken out by pressing, drying, and corrugating. Figure 1 As shown, the sizing system is to mix the long fibers and short fibers in the mixing tank and the stock preparation tank, and then transport them to the pulping tank. While the pulping tank is stirring and mixing, the slurry is output through the sizing pump in sequence to the concentration agent, the high-level stabilizing box, the base weight valve, the fan pump for dilution, and the paper machine screen to the head box.

[0003] In the above process, the slurry pump motor is a non-variable frequency motor, and it is necessary to pump slurry with stable concentration to a high-level stabilizing box at a height of 15m. The stabilizing box enters the fan pump through the base weight valve at a stable pressure in a liquid level control manner. After the set liquid level is reached in the high-level stabilizing box, the excess part is returned to the slurry tank through the pipeline control valve, and the control valve of the return pipe is adjusted to stabilize the liquid level. In the whole process, in order to meet the slurry must reach the stabilizing box with a high lift of 15m and enter the base weight valve with a stable pressure; the slurry pump motor must always be running at full load, resulting in a waste of electricity consumption, which is not conducive to energy saving.

[0004] The installation of a high-position stabilizing box takes up a relatively large space and requires many pipes. During use, slurry is easily accumulated on the top and sides of the stabilizing box. Once the accumulated slurry forms blocks and falls into the slurry pipe, it will cause the base weight valve to be blocked, affecting the fluctuation of slurry flow and causing paper breakage. Sometimes it will directly block the base weight valve and result in no slurry flow. The high-position stabilizing box must be shut down regularly for cleaning and flushing, affecting processing efficiency. Summary of the invention

[0005] Purpose of the invention: The purpose of the invention is to provide a toilet paper machine pressure-stabilizing sizing device that reduces energy waste and lowers the failure rate.

[0006] Technical solution: The present invention adopts a pressure-stabilizing sizing device for a toilet paper machine, including a slurry tank for stirring and mixing long fibers and short fibers, a sizing pump, a base weight valve, and a control system. The input end of the sizing pump is connected to the slurry tank, and the output end of the sizing pump is connected to the input end of the base weight valve through a sizing pipeline. The sizing pipeline is provided with a concentration meter and a pressure gauge, and the pressure gauge is used to detect the pipeline pressure in the sizing pipeline. The sizing pump adopts a variable frequency motor, and the control system controls the speed of the variable frequency motor according to the pipeline pressure measured by the pressure gauge.

[0007] Furthermore, the input end of the pulping tank is connected to the output end of the mixing tank, and the mixing tank is used to mix the long fibers and the short fibers.

[0008] Furthermore, the output end of the base weight valve is connected to the input end of the fan pump, and the output end of the fan pump is connected to the head box through the paper machine screen. The pulp enters the fan pump through the base weight valve for dilution and is transported to the head box through the paper machine screen.

[0009] Furthermore, the control system is used to increase the speed of the variable frequency motor when the pipeline pressure measured by the pressure gauge is lower than the set pressure; and to reduce the speed of the variable frequency motor when the pipeline pressure measured by the pressure gauge is higher than the set pressure.

[0010] Furthermore, the control system includes a manual control module and an automatic control module, the manual control module is used to control the speed of the variable frequency motor according to the manually input motor speed, and the automatic control module is used to automatically control the speed of the variable frequency motor according to the pipeline pressure measured by the pressure gauge.

[0011] Furthermore, the set pressure ranges from 1.0 bar to 1.2 bar.

[0012] Furthermore, the lift of the sizing pipeline is 5.5m-6.5m.

[0013] Beneficial effects: Compared with the prior art, the advantages of the present invention are: reducing downtime caused by failures due to the motor running at full load all the time, and reducing maintenance costs. The pipe head is reduced from 15m to 6m, reducing the energy waste caused by the pipe head and the slurry returning to the pulping tank. It saves the installation space of the stabilizing box and the reflux control valve, and simplifies the system structure. It reduces the loss of abnormal downtime due to paper breaking caused by the slurry block on the top and wall of the stabilizing box blocking the base weight valve and affecting the slurry flow fluctuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of a pressure-stabilizing sizing device for a toilet paper machine in the prior art;

[0015] Figure 2 It is a schematic structural diagram of the pressure-stabilizing sizing device of a toilet paper machine in the present invention. DETAILED DESCRIPTION

[0016] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figure 2As shown, in this embodiment, a stabilizing sizing device for a toilet paper machine includes a mixing tank, a slurry tank for mixing long fibers and short fibers, a slurry pump, a base weight valve, a control system, a fan pump, a paper machine screen and a head box. The mixing tank is used to mix long fibers and short fibers. The input end of the slurry tank is connected to the output end of the mixing tank. The input end of the slurry pump is connected to the slurry tank. The output end of the slurry pump is connected to the input end of the base weight valve through a slurry pipeline. The slurry pipeline is provided with a concentration meter and a pressure gauge. The pressure gauge is used to detect the pipeline pressure in the slurry pipeline. The slurry pump adopts a variable frequency motor. The control system controls the speed of the variable frequency motor according to the pipeline pressure measured by the pressure gauge. The output end of the base weight valve is connected to the input end of the fan pump, and the output end of the fan pump is connected to the head box through the paper machine screen. The slurry enters the fan pump through the base weight valve for dilution and is transported to the head box through the paper machine screen. The high-position stabilizing slurry box is removed, and the slurry pipe directly enters the fan pump through the base weight valve, and the pipeline head is reduced from 15m to 6m.

[0018] Change the pump motor to a variable frequency motor, add a motor speed setting box on the DCS screen, and a manual and automatic switching button. In the manual state, the motor speed can be manually input to meet the sizing amount; in the automatic state, the sizing pump speed is automatically adjusted according to the sizing pipeline pressure to meet the pressure.

[0019] Add a pressure gauge after the concentration meter and display the real-time pressure of the sizing pipeline on the DCS screen. Add a pressure setting box to manually input the actual pressure that needs to be controlled in the pipeline. Generally, the setting pressure range of the sizing pipeline is controlled at 1.0bar-1.2bar.

[0020] The speed of the variable frequency motor is adjusted manually or automatically by setting the pressure of the pipeline, so that the actual pressure of the pipeline is stabilized at the set pressure. If the actual pressure of the sizing pipeline is too low, insufficient sizing flow will cause the base paper weight to be too low or paper breakage. At this time, if the motor speed is set in manual mode, the motor speed must be manually increased until the actual pressure of the sizing pipeline reaches the set pressure. At this time, if the motor speed is set in automatic mode, the side sizing motor will automatically adjust the speed until the actual pressure of the sizing pipeline reaches the set pressure.

[0021] If the pressure in the sizing pipeline is too high, the excess sizing will cause the pipeline to be pressurized, resulting in a high motor speed and wasting energy; at this time, if the motor speed is set in manual mode, the motor speed must be manually reduced until the actual pressure in the sizing pipeline reaches the set pressure; at this time, if the motor speed is set in automatic mode, the sizing motor will automatically adjust the speed until the actual pressure in the sizing pipeline reaches the set pressure.

Claims

1. A stabilizing sizing device for a toilet paper machine, characterized in that: It includes a pulping tank for stirring and mixing long fibers and short fibers, a sizing pump, a base weight valve, and a control system. The input end of the sizing pump is connected to the pulping tank, and the output end of the sizing pump is connected to the input end of the base weight valve through a sizing pipeline. The sizing pipeline is provided with a concentration meter and a pressure gauge, and the pressure gauge is used to detect the pipeline pressure in the sizing pipeline. The sizing pump adopts a variable frequency motor, and the control system controls the speed of the variable frequency motor according to the pipeline pressure measured by the pressure gauge.

2. The toilet paper machine pressure stabilizing sizing device according to claim 1, characterized in that: The input end of the pulping tank is communicated with the output end of the mixing tank, and the mixing tank is used to mix the long fibers and the short fibers.

3. The toilet paper machine pressure stabilizing sizing device according to claim 1, characterized in that: The output end of the base weight valve is connected to the input end of the fan pump, and the output end of the fan pump is connected to the head box through the paper machine screen. The pulp enters the fan pump through the base weight valve for dilution and is transported to the head box through the paper machine screen.

4. The stabilizing sizing device for a toilet paper machine according to claim 1, characterized in that: The control system is used to increase the speed of the variable frequency motor when the pipeline pressure measured by the pressure gauge is lower than the set pressure; and to reduce the speed of the variable frequency motor when the pipeline pressure measured by the pressure gauge is higher than the set pressure.

5. The stabilizing sizing device for toilet paper machine according to claim 4, characterized in that: The control system includes a manual control module and an automatic control module. The manual control module is used to control the speed of the variable frequency motor according to the motor speed manually input, and the automatic control module is used to automatically control the speed of the variable frequency motor according to the pipeline pressure measured by the pressure gauge.

6. The stabilizing sizing device for a toilet paper machine according to claim 4, characterized in that: The set pressure ranges from 1.0 bar to 1.2 bar.

7. The stabilizing sizing device for a toilet paper machine according to claim 1, characterized in that: The lift of the sizing pipeline is 5.5m-6.5m.

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