CN101705633A - Device for controlling pulping process and control method thereof - Google Patents

Abstract

The invention discloses a control device and a control method for the beating process. The device includes a first pulp storage tank, a pulp pump, a second pulp storage tank, and a beater connected in sequence; a mixer with dilution water is provided in the first pulp storage tank, and a dilution water pipe is provided on the slurry inlet pipe of the pulp pump. A pulp concentration gauge is provided on the pulp outlet pipe of the pump, a liquid level gauge is provided in the second pulp storage tank, and a flow meter is arranged on the pulp outlet pipe of the beater. The method of the invention realizes the control of the beating process through constant pulp concentration, constant pulp flow rate and constant beating power. The device and method provided by the present invention realize the beating process under the conditions of the set pulp concentration, flow rate, pressure and beating power, which is beneficial to the stability of beating quality and paper quality, reduces the energy consumption of the beating process, and improves the quality of paper. physical properties.

Description

A control device and control method for beating process

technical field

The invention belongs to the field of pulping and papermaking, in particular to a control device and a control method for a beating process.

Background technique

The pulp and paper industry uses plant fibers as the main raw material. The plant fiber raw materials are dispersed into pulp fibers through material preparation, chemical or mechanical pulping processes, and the whiteness and whiteness stability are improved through bleaching to become pulp fibers for papermaking. However, before being sent to the paper machine to make paper, the pulp fibers must also be treated by beating equipment.

Beating is an important technical link in the preparation process of papermaking pulp. Its purpose is to change the physical form of fiber raw materials (fiber swelling, delamination, fibrillation and cutting, etc.) by applying force, so that the pulp Obtain certain characteristics to ensure the quality requirements of the paper or paperboard to be made, and to meet the performance requirements of the paper machine. Pulping is a complex process affected by many factors, which has an important impact on papermaking energy consumption, pulp fiber characteristics and paper physical properties.

The traditional beating process is controlled manually. With the expansion of industrial production scale and technological progress, the automatic control of beating process has been widely valued and continuously developed. Realizing the automatic control of beating process can reduce the fluctuation of beating quality, increase output and reduce energy consumption, which is one of the development directions of beating technology.

At present, there are mainly two technical directions for the control of the beating process. One control method adopts specific energy consumption control, that is, under the condition that the motor speed of the beater is constant, the energy consumption required by the unit absolute dry fiber amount is set, and the fiber throughput during beating is calculated by detecting the concentration and flow rate of pulp fibers , so that the required beating power can be calculated. This method needs to detect the concentration and flow of pulp in real time. When the concentration and flow of pulp fluctuate, it is necessary to adjust the gap between the movable grinding plate and the fixed grinding plate of the beater to adjust the beating power. Because the feedback of the system takes time, when the gap between the movable grinding plate and the fixed grinding plate is adjusted according to the last concentration and flow detection value, the pulp concentration and flow rate may fluctuate again, so it is actually difficult to calculate the energy per unit dry fiber amount Consumption is maintained at the set value. Another control method belongs to the beating quality control method. This method adopts online detection of beating quality (pulp beating degree, wet weight), and adjusts the beating motorized grinding plate and fixed grinding plate through the deviation between the beating quality measurement value and the set value. Sheet gap, so that the pulp quality is stable. Although some progress has been made in the development of domestic beating quality on-line measuring instruments, there is still a big gap from industrial application. Foreign measuring instruments are not only expensive, but also may not meet domestic needs. Therefore, the soft measurement technology of pulp quality is generally adopted to realize the control of pulp quality. However, due to the complexity of the beating process, there are many factors that affect the beating, which determines that any soft-sensing model has limitations and its adaptability is not too wide.

Contents of the invention

The purpose of the present invention is to overcome the disadvantages of the prior art and provide a control device for the beating process with high and stable pulp quality, stable paper physical properties and low beating energy consumption.

Another object of the present invention is to provide a method for controlling the beating process.

The object of the present invention is achieved through the following technical solutions:

A control device for the beating process, characterized in that it includes a first pulp storage tank, a pulp pump, a pulp pump inlet pipe, a pulp pump outlet pipe, a second pulp storage tank, a beater, a pulper inlet pipe and a beater The pulp outlet pipe; the pulp pump inlet pipe and the pulp pump outlet pipe are connected with the pulp pump, the pulp inlet pipe of the beater and the pulp outlet pipe of the beater are connected with the beater; the first pulp outlet at the lower end of the first pulp storage tank is connected with the pulp pump The slurry inlet pipe is connected, and a mixer with dilution water is installed near the first slurry outlet in the first slurry storage tank; the agitator with dilution water is connected with the first dilution water pipe; the slurry pump inlet tube is provided with a first valve; the slurry pump The pulp inlet pipe is connected with the second dilution water pipe; the pulp pump outlet pipe is equipped with a pulp concentration gauge; the pulp flowing out of the pulp pump outlet pipe enters the second pulp storage tank; the second pulp storage tank is equipped with a liquid level gauge; The second pulp outlet at the lower end of the pulp storage tank is connected to the pulp inlet pipe of the beater; the pulp inlet pipe of the beater is provided with a second valve; the pulp outlet pipe of the beater is provided with a flow meter.

Further, the bottom of the first slurry storage tank has a gradually shrinking shape.

Further, the second slurry storage tank has an inverted conical bottom.

A control method for beating process, characterized in that:

(1) Constant pulp concentration: the pulp concentration is roughly adjusted through the agitator with dilution water installed in the first pulp storage tank, and the pulp concentration is adjusted through the pulp concentration meter and the second dilution water pipe connected to the pulp pump inlet pipe. Fine-tuning to realize the beating process under the set pulp concentration;

When the concentration displayed by the pulp concentration meter is higher or lower than the set value, the concentration of the pulp is adjusted by increasing or decreasing the amount of dilution water added, and the agitator with dilution water is used to roughly adjust the concentration of the pulp, and the pulp flows into the pulp pump. After that, the pulp concentration is fine-tuned through the dilution water pipe on the pulp pump inlet pipe to maintain the pulp concentration at the set value;

(2) Constant pulp flow rate: through the flow meter arranged on the outlet pipe of the beater, the second valve arranged on the inlet pipe of the beater and the liquid level gauge arranged on the second pulp storage tank, the pulp passing through the beater is checked. The throughput is adjusted so that the beating is carried out at the set flow rate;

When the pulp flow rate displayed by the flowmeter is lower than the set value, if the liquid level displayed by the liquid level gauge has room to increase at this time, then increase the pulp liquid level in the second pulp storage tank to increase the beating pressure and increase the pulp flow rate; When the liquid level gauge shows that the pulp liquid level in the second pulp storage tank is at the highest level, increase the pulp flow by increasing the opening of the second valve on the pulp inlet pipe of the beater to maintain the pulp flow at the set value;

When the pulp flow rate displayed by the flow meter is higher than the set value, the pulp flow rate can be reduced by reducing the pulp level in the second pulp storage tank and/or reducing the opening of the second valve on the pulp inlet pipe of the beater, so that the pulp The flow rate is maintained at the set value;

The adjustment of the pulp liquid level in the second pulp storage tank is adjusted by the opening of the first valve in front of the pulp pump;

(3) Constant beating power: the beating power is adjusted by adjusting the gap between the dynamic grinding plate and the fixed grinding plate of the beating machine, so that the beating process can be carried out under the set power condition.

The control device and control method of the beating process provided by the present invention realize beating under the set pulp concentration, flow rate, pressure and beating power. Under this condition, according to the modern beating theory, if the speed of the beating machine is maintained at At a certain level, the intensity of beating treatment received by pulp fibers when passing through the grinding zone of the beater is certain, and at the same time, the degree of beating treatment received by pulp fibers when passing through the grinding zone of the beater (expressed by the beating energy consumption per unit dry mass pulp ) is also certain, thereby realizing the beating process under the condition of setting beating intensity and beating degree.

Compared with the prior art, the present invention has the following advantages:

1. The present invention makes beating under the conditions of set pulp concentration, flow rate, pressure and beating power through the adjustment and setting of pulp concentration, pulp throughput of beating machine and power of beating machine during beating, and realizes beating under the conditions of set beating power. The beating process under the conditions of treatment intensity and beating treatment degree greatly reduces the fluctuation of beating quality caused by the fluctuation of various factors in the beating process, greatly improves the stability of pulp quality and the stability of paper physical properties, and is conducive to reducing the beating energy. consumption, improve pulp quality, and improve paper physical properties.

2. In the existing beating control method, the concentration and flow of pulp will fluctuate greatly. It is necessary to adjust the gap between the dynamic grinding plate and the fixed grinding plate of the beater to adjust the beating power. Trouble, but the present invention can keep the concentration and flow of the pulp well, so that the beating power is constant during the beating process, and there is no need to adjust the gap between the movable grinding plate and the fixed grinding plate, thereby improving the stability of the pulp quality and the physical properties of the paper of stability.

3. The invention has simple equipment, wide application range, low cost, low operation cost, convenient operation and maintenance, and easy popularization and application.

Description of drawings

Fig. 1 is a schematic diagram of the control device of the beating process provided by the present invention.

In the figure, 1: first slurry storage tank; 2: agitator with dilution water; 3: first dilution water pipe; 4: second dilution water pipe; 5: first valve; 6: slurry pump inlet pipe; 7: slurry Pump; 8: pulp pump outlet pipe; 9: pulp concentration meter; 10: second pulp storage tank; 11: liquid level gauge; 12: pulper inlet pipe; 13: second valve; 14: beater; 15 : pulper outlet pipe; 16: flow meter.

Detailed ways

The present invention will be further specifically described below in conjunction with the accompanying drawings and examples, but the protection scope of the present invention is not limited to the scope expressed in the examples.

Example

As shown in Figure 1, the control device of the beating process provided by the present invention includes a first pulp storage tank 1, a pulp pump inlet pipe 6, a pulp pump 7, a pulp pump outlet pipe 8, a second pulp storage tank 10, a pulp pump Machine pulp inlet pipe 12, beater 14, pulper outlet pipe 15, agitator with dilution water 2, first dilution water pipe 3, second dilution water pipe 4, pulp concentration meter 9, liquid level meter 11, flow meter 16 , the first valve 5, the second valve 13;

The agitator 2 with dilution water is arranged in the slurry storage tank 1, and the first dilution water pipe 3 is the dilution water inlet pipe with the agitator 2 for dilution water;

One end of the slurry pump inlet pipe 6 is connected to the first slurry storage tank 1, and the other end is connected to the slurry pump 7. The slurry pump inlet pipe 6 is provided with a first valve 5 and connected to the second dilution water pipe 4;

The pulp concentration meter 9 is set on the slurry pump outlet pipe 8;

The liquid level gauge 11 is arranged on the second slurry storage tank 10;

One end of the pulp inlet pipe 12 of the beater is connected to the bottom of the second pulp storage tank 10, and the other end is connected to the beater 14, and the pulp inlet pipe 12 of the beater is provided with a second valve 13;

The flow meter 16 is arranged on the slurry outlet pipe 15 of the beater;

The bottom of the first slurry storage tank 1 has a shape that gradually shrinks toward the side where the agitator 2 with dilution water is provided;

The second slurry storage tank 10 has an inverted conical bottom.

In this embodiment, bleached eucalyptus pulp is used as raw material, the beating concentration is set to be 4.5%, the pulp flow rate is 20Kg/min, the beating power is 110Kw, and the synchronous speed of beating motorized grinding discs is 1500rpm. The control method of the beating process of the present invention includes the following Steps and process conditions:

1. Pulp concentration adjustment: the pulp concentration in the first pulp storage tank is about 8%, the pulp concentration is roughly adjusted by the agitator 2 with dilution water arranged in the first pulp storage tank 1, and the pulp concentration meter 9 and setting The second dilution water pipe 4 on the pulp pump inlet pipe 6 fine-tunes the pulp concentration to realize the beating process at a set pulp concentration of 4.5%;

When the concentration displayed by the concentration meter 9 is higher or lower than the set value of 4.5%, the concentration of the pulp is adjusted by increasing or decreasing the amount of dilution water added. Carry out rough adjustment, and then fine-tune the pulp concentration through the second dilution water pipe 4 on the pulp pump inlet pipe 6, so that the pulp concentration is maintained at a set value of 4.5%;

2. Pulp flow adjustment: through the flow meter 16 arranged on the pulp outlet pipe 15 of the beater, the second valve 13 arranged on the pulp inlet pipe 12 of the beater and the liquid level gauge 11 of the second pulp storage tank 10 through the pair of pulping Adjust the pulp throughput of the machine so that the beating is carried out at the set flow rate;

When the pulp flow rate shown by the flow meter 16 is lower than the set value of 20Kg/min, if the liquid level shown by the liquid level meter 11 has room for improvement, then increase the pulp liquid level in the second pulp storage tank 10 to increase beating pressure to increase the pulp flow; when the liquid level gauge 11 shows that the pulp liquid level in the second pulp storage tank 10 is at the highest level, then increase the pulp flow by increasing the opening of the second valve 13 on the pulp inlet pipe 12 of the beater, Keep the pulp flow at the set value of 20Kg/min;

When the pulp flow shown by the flow meter 16 was higher than the set value 20Kg/min, by reducing the pulp liquid level of the second pulp storage tank 10 and/or reducing the opening of the second valve 13 on the pulper feed pipe 12 Reduce the pulp flow to maintain the pulp flow at the set value of 20Kg/min;

The adjustment of the pulp liquid level in the second pulp storage tank 10 is adjusted by the opening of the first valve 5 in front of the pulp pump 7;

3. Adjustment of beating power: the beating power is adjusted by adjusting the gap between the movable grinding plate and the fixed grinding plate of the beating machine 14, so that the beating process is carried out under the condition of a set power of 110Kw.

During the beating process, the beating is carried out under the set pulp concentration, flow rate, pressure and beating power.

The above beating process achieves a good beating effect, the beating energy consumption is reduced by more than 15%, and the physical properties of paper are increased by more than 10%.

Claims (4)

1. the control device of a pulping process is characterized in that comprising first reserve pit (1), stock pump (7), stock pump pulp-inlet pipe (6), stock pump grout outlet (8), second reserve pit (10), beater (14), beater pulp-inlet pipe (12) and beater grout outlet (15); Stock pump pulp-inlet pipe (6) links to each other with stock pump (7) with stock pump grout outlet (8), and beater pulp-inlet pipe (12) links to each other with beater (14) with beater grout outlet (15); First grout outlet of first reserve pit (1) lower end links to each other with stock pump pulp-inlet pipe (6), is provided with band dilution water agitator (2) near first grout outlet in first reserve pit (1); Band dilution water agitator (2) links to each other with the first dilution water pipe (3); Stock pump pulp-inlet pipe (6) is provided with first valve (5); Stock pump pulp-inlet pipe (6) links to each other with the second dilution water pipe (4); Stock pump grout outlet (8) is provided with pulp density meter (9); The paper pulp that stock pump grout outlet (8) flows out enters second reserve pit (10); Second reserve pit (10) is provided with liquid level gauge (11); Second grout outlet of second reserve pit (10) lower end links to each other with beater pulp-inlet pipe (12); Beater pulp-inlet pipe (12) is provided with second valve (13); Beater grout outlet (15) is provided with flowmeter (16).

2. the control device of pulping process according to claim 1 is characterized in that the bottom of first reserve pit (1) has the shape of shrinking gradually.

3. the control device of pulping process according to claim 1 is characterized in that second reserve pit (10) has the bottom of back taper.

4. the control method of a pulping process is characterized in that:

(1) constant pulp density: by the band dilution water agitator (2) that is arranged in first reserve pit (1) pulp density is carried out coarse adjustment, pulp density finely tuned with the second dilution water pipe (4) that links to each other with stock pump pulp-inlet pipe (6) by pulp density meter (9), be implemented in the pulping process of setting under the pulp density; When the concentration of pulp density meter (9) demonstration was higher or lower than setting value, the concentration by the addition that increases or reduce dilution water is regulated paper pulp made pulp density maintain setting value;

(2) constant pulp flow:, making beating is carried out under the flow of setting by being arranged on flowmeter (16) on the beater grout outlet (15), being arranged on second valve (13) on the beater pulp-inlet pipe (12) and the liquid level gauge (11) that is arranged on second reserve pit (10) is regulated the paper pulp throughput by beater;

When the pulp flow of flowmeter (16) demonstration was lower than setting value, if the liquid level that liquid level gauge this moment (11) shows has the space of raising, the paper pulp liquid level that then improves second reserve pit (10) increased beating pressure, the increase pulp flow; The paper pulp liquid level that shows second reserve pit (10) when liquid level gauge (11) has been in highest level, then improves pulp flow by the aperture that strengthens beater pulp-inlet pipe (12) last second valves (13), makes pulp flow maintain setting value;

When the pulp flow of flowmeter (16) demonstration is higher than setting value, can reduce pulp flow by paper pulp liquid level that reduces by second reserve pit (10) and/or the aperture that reduces last second valve of beater pulp-inlet pipe (12) (13), make pulp flow maintain setting value;

The adjusting of the paper pulp liquid level of described second reserve pit (10) is by the aperture size adjustment of preceding first valve (5) of stock pump (7);

(3) constant making beating power: the moving abrasive disc by regulating beater (14) and decide refining plate interval and regulate making beating power carries out pulping process under the power condition of setting.