Alkali Concentration Control Method for Dyeing and Finishing Equipment

Abstract

The present invention discloses a method for controlling the alkali concentration of a dyeing and finishing equipment. The dyeing and finishing equipment includes a working tank, and is also provided with a preparation tank and an alkali concentration detection mechanism for detecting the alkali solution concentration of the working tank and the preparation tank. The method includes detecting the real-time concentration value Pi of the alkali solution in the working tank, comparing Pi with the process-set concentration value Ci of the alkali solution. If Pi < Ci - ΔW, an alkali solution with a concentration of Cj is prepared in the preparation tank, where Cj = (Ci + ΔK); the alkali solution in the preparation tank is quantitatively added to the working tank; detecting the real-time concentration value Pj+(n-1) of the alkali solution in the working tank. If Pj+(n-1) < Ci - ΔW, the preparation tank prepares an alkali solution with a concentration of Cj+n = Cj+(n-1) + ΔK, and returns to step (1c) to execute sequentially until Ci - ΔW ≤ Pj+(n-1) ≤ Ci + ΔW, and then returns to step (1) to execute sequentially. The present invention can keep the alkali solution concentration in the working tank always within the range of the process-set concentration value.

Description

Technical Field

[0001] The present invention relates to a method for controlling alkali concentration, in particular to a method for controlling alkali concentration in dyeing and finishing equipment, belonging to the technical field of textile dyeing and finishing processes. Background Art

[0002] In the dyeing and finishing process, there is usually a process of impregnating the fabric with alkali liquor in a working tank for mercerization / alkali shrinking treatment. The alkali liquor concentration in the working tank is a key process parameter. Making the alkali liquor concentration in the working tank meet the process-set concentration value range and remain constant can improve the surface gloss and hand feeling of the fabric, increase the dye uptake rate, and improve the dimensional stability of the fabric for the mercerization process; for the alkali shrinking process, it can increase the tissue density and elasticity of the knitted fabric. Therefore, the alkali liquor concentration in the working tank directly affects the appearance quality of the fabric, dyeing, and post-finishing processes.

[0003] Dyeing and finishing equipment such as alkali shrinking machines and mercerizing machines usually have working tanks for impregnating alkali liquor, and the fabric is treated by impregnating it with alkali liquor in the working tank. The existing methods for controlling the alkali liquor concentration in the working tank usually adopt the manual titration method. The operator manually adjusts the size of the valve to add or supplement raw alkali, dilute alkali, or water to control the alkali liquor concentration in the working tank. However, there are the following disadvantages in using manual titration in work: The titration results of different operators are often different, and errors are extremely likely to occur; there is a huge time interval between detecting and adjusting the alkali liquor concentration. During this interval, the concentration of the alkali liquor has changed again, so the adjusted value is not adjusted according to the concentration at the adjustment moment, and there is a large error; in the manual mode, continuous detection cannot be achieved, and the alkali liquor concentration cannot be continuously adjusted, so it is difficult to keep the alkali liquor always at the set concentration value, affecting the reproducibility of the subsequent dyeing process, resulting in a high defective rate of the fabric, unable to achieve automatic control, increasing the number of workers and labor costs, causing waste of resources such as water, steam, and chemicals, increasing the sewage treatment cost, and affecting the environment, which urgently needs improvement.

[0004] Chinese Utility Model Patent ZL201721205724.5 named: An Automatic Control Device for Alkali Quantity in an Alkali Weight Reduction Machine, Chinese Utility Model Patent ZL201120374805.4 named: On-line Measurement and Control System for Alkali Concentration in Alkali Weight Reduction Process, etc. patents all disclose a method for controlling alkali liquor concentration. The common point is that they do not set up a preparation tank for preparing alkali liquor, but only set up a working tank for impregnating alkali liquor. During the continuous operation of the fabric for alkali weight reduction treatment, in order to adjust the alkali liquor concentration in the working tank to the process-set concentration value, the method adopted is to directly add raw alkali, dilute alkali, or water into the working tank. This is very likely to cause the ratio concentration of alkali to be sometimes high and sometimes low, with poor concentration stability, and it is easy to have uneven fusion of concentrated alkali during the alkali liquor fusion process, resulting in stratification of alkali and water.

[0005] Therefore, the technical solutions provided by the prior art cannot well solve the actual working condition problems. In the mercerizing / alkali shrinking process, the alkali liquor concentration in the working tank cannot reach the requirements of fabric alkali padding / impregnation, directly affecting the quality of the processed fabric. For example, a significant reduction in the barium value of mercerized fabric will affect the mercerizing effect, resulting in differences in mercerizing effect, alkali content on the fabric, and fabric width. These have a very obvious impact on fabric dyeing, causing color differences in fabric dyeing. In the alkali shrinking process, the tissue density and elasticity of the fabric do not meet the standards, often resulting in product rejection or rework, low product qualification rate, and high processing costs. Measuring and controlling the alkali liquor concentration in the working tank during the dyeing and finishing process has always been a difficult technical problem, and there is no good solution in the prior art. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for controlling the alkali concentration of a dyeing and finishing equipment that can continuously detect and adjust the alkali liquor concentration in the working tank, with high adjustment accuracy of the alkali liquor concentration, uniform fusion of alkali and water, and keeping the alkali liquor concentration in the working tank always within the range of the process-set concentration value.

[0007] To solve the above technical problem, the present invention adopts such a method for controlling the alkali concentration of a dyeing and finishing equipment. The dyeing and finishing equipment includes a working tank for impregnating alkali liquor, a preparation tank for preparing alkali liquor, and an alkali concentration detection mechanism for detecting the alkali liquor concentration in the working tank and the preparation tank. The control method includes the following steps:

[0008] (1) The alkali concentration detection mechanism detects the real-time concentration value P of the alkali liquor in the working tank i , and compares the real-time concentration value P i with the process-set concentration value C of the alkali liquor i .

[0009] (1a) If P i < C i - ΔW, where ΔW is the allowable concentration error value and ΔW ≥ 0;

[0010] (1b) Configure alkali liquor with a concentration of C j in the preparation tank, C j = (C i + ΔK), where ΔK is the alkali concentration adjustment increment and ΔK > 0;

[0011] (1c) Add the alkali liquor in the preparation tank to the working tank;

[0012] (1d) The alkali concentration detection mechanism detects the real-time concentration value P of the alkali liquor in the working tank after step (1c) j+（n-1） , if P j+（n-1） < C i - ΔW, the preparation tank configures a concentration of C j+n = C j+（n-1）The lye of +ΔK, where n is a positive integer, return to step (1c) and execute sequentially. When step (1c) and (1d) are executed for the first time, n is 1. When executed for the second time, n is 2, and so on until C i -ΔW ≤ P j+（n-1） ≤ C i When +ΔW, return to step (1) and execute sequentially.

[0013] As a preferred embodiment of the present invention, after step (1),

[0014] (2a) If the P i > C i When +ΔW, ΔW is the allowable concentration error value, ΔW ≥ 0;

[0015] (2b) Configure lye with a concentration of C f in the preparation tank, C f = (C i -ΔK), where ΔK is the lye concentration adjustment increment, ΔK > 0;

[0016] (2c) Add the lye in the preparation tank to the working tank;

[0017] (2d) The lye concentration detection mechanism detects the real-time concentration value P f+（n-1） of the lye in the working tank after step (2c). If P f+（n-1） > C i +ΔW, configure lye with a concentration of C f+n = C f+（n-1） -ΔK, where n is a positive integer, return to step (2c) and execute sequentially. When step (2c) and (2d) are executed for the first time, n is 1. When executed for the second time, n is 2, and so on until C i -ΔW ≤ P f+（n-1） ≤ C i When +ΔW, return to step (1) and execute sequentially.

[0018] As another preferred embodiment of the present invention, after step (1),

[0019] (3a) If the P i > C i When +ΔW, ΔW is the allowable concentration error value, ΔW ≥ 0;

[0020] (3b) According to the P i , C i and the real-time lye volume V in the working tank, calculate and discharge the lye volume △V in the working tank, △V = V×(P i -C i )÷P i ;

[0021] (3c) Add water equal to ΔV to the working tank to make the alkali concentration within C i ±ΔW range, and return to step (1) to execute sequentially.

[0022] As a preferred embodiment of the present invention, 0.1%C i ≤ΔW≤10%C i , 1%C i ≤ΔK≤30%C i .

[0023] As a preferred embodiment of the present invention, the alkali concentration detection mechanism includes an alkali liquid detection flow cell provided with an alkali liquid concentration sensor. The working tank is connected to the alkali liquid detection flow cell through a first pipeline, and the preparation tank is connected to the alkali liquid detection flow cell through a second pipeline. A first control valve is provided on the first pipeline, and a second control valve is provided on the second pipeline. The alkali liquid concentration sensor, the first control valve, and the second control valve are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller.

[0024] As a preferred embodiment of the present invention, the alkali concentration detection mechanism includes a first alkali liquid concentration sensor and a second alkali liquid concentration sensor; the first alkali liquid concentration sensor is used to detect the alkali liquid concentration in the working tank, the second alkali liquid concentration sensor is used to detect the alkali liquid concentration in the preparation tank, and the first and second alkali liquid concentration sensors are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller.

[0025] As a preferred embodiment of the present invention, the dyeing and finishing equipment is provided with a first liquid level sensor and a second liquid level sensor; the first liquid level sensor is used to detect the alkali liquid level in the working tank, the second liquid level sensor is used to detect the alkali liquid level in the preparation tank, and the first and second liquid level sensors are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller.

[0026] As a preferred embodiment of the present invention, the preparation tank is provided with an alkali liquid input pipe and a water inlet pipe. An alkali inlet control valve is provided on the alkali liquid input pipe, and a water inlet control valve is provided on the water inlet pipe. The alkali inlet control valve and the water inlet control valve are controlled by the electric controller of the dyeing and finishing equipment or an independently provided electric controller.

[0027] As a preferred embodiment of the present invention, a communication pipe is provided between the working tank and the preparation tank, and a control pump / valve is provided on the communication pipe. The control pump / valve is controlled by the electric controller of the dyeing and finishing equipment or an independently provided electric controller.

[0028] As a preferred embodiment of the present invention, the working tank is provided with a clean water addition pipe and an alkali liquid discharge pipe. A water addition control valve is provided on the clean water addition pipe, and a alkali discharge control valve is provided on the alkali liquid discharge pipe. The water addition control valve and the alkali discharge control valve are controlled by the electric controller of the dyeing and finishing equipment or an independently provided electric controller.

[0029] After adopting the above method, the present invention has the following beneficial effects:

[0030] The present invention is provided with a preparation tank for preparing alkali solution and an alkali concentration detection mechanism for detecting the alkali solution concentrations in the working tank and the preparation tank. On the one hand, by detecting the alkali solution concentrations in the working tank and the preparation tank in real time, analyzing the deviation between the two in a timely manner, and injecting a relatively small amount of prepared alkali solution from the preparation tank to the working tank in a timely manner, the alkali solution concentration in the working tank is always maintained linearly. The entire control method is more conducive to the automatic adjustment and control of the alkali solution concentration in the working tank. The linear result is stable, the homogeneity of the alkali solution concentration is good, and the control accuracy is high, fully ensuring that the alkali content of each part of the fabric is consistent and solving the problem of fabric color difference. On the other hand, the detected data of the alkali solution concentrations in the working tank and the preparation tank can be mutually verified, with high confidence, and can automatically, accurately and stably control the alkali solution concentration during the production process. Finally, the alkali solution concentration in the working tank is always within the range of the process-set concentration value, reducing the defective rate and rework rate of the fabric and improving the fabric quality and production efficiency.

[0031] The present invention solves the technical problem in the prior art that directly mixing raw alkali into the working tank results in high and low alkali ratio concentrations, poor concentration stability, and easy uneven fusion of concentrated alkali during the fusion process of the alkali solution in the working tank, causing stratification of alkali and water, local over-concentration of the alkali solution concentration, and poor alkali reduction / mercerization effects. The present invention makes the fusion of alkali and water uniform, makes the density of the product more uniform and unified after alkali shrinkage, has a high mercerization barium value, and further improves the fabric quality.

[0032] The present invention has a small alkali solution concentration gradient between the working tank and the preparation tank, enabling the working tank to quickly and accurately obtain the alkali solution concentration value that meets the requirements, greatly reducing the system inertia and lag time delay of alkali preparation control. The alkali solution concentration value in the process of alkali solution concentration control is closer to the target value, with small alkali solution concentration fluctuations, improving the dyeing depth, vividness, and fullness of the fabric, and making the fabric present good luster.

[0033] The present invention automatically prepares alkali, continuously detects and adjusts the alkali solution concentration in the working tank, with high alkali solution concentration adjustment accuracy, greatly improving the automation and intelligent level of production equipment. In particular, it well improves the detection and control of the key quality indicators of products during the production process, greatly reducing the labor cost during the processing process and enhancing the competitiveness of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The following further details the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0035] Figure 1 It is a schematic diagram of the first working state of the working tank, preparation tank, and alkali concentration detection mechanism of the present invention.

[0036] Figure 2This is a schematic diagram of the second working state of the working tank, preparation tank and alkali concentration detection mechanism of the present invention. Detailed implementation manners

[0037] For the dyeing and finishing equipment of the present invention, such as a clip mercerizing machine, in the process of impregnating and padding with alkali, in the mercerizing process, alkali liquor (sodium hydroxide solution) is used in the working tank to treat the fabric to increase the surface luster of the fabric. Different alkali liquor concentrations produce different mercerizing effects. According to the process requirements, the alkali liquor concentration in the working tank, i.e., the impregnating and padding alkali tank, needs to be controlled correspondingly according to the classification of the fabric, the fabric structure, the gram weight of the fabric, etc. Generally, the alkali liquor concentration for mercerizing cotton knitted fabric is controlled at 250-290 g / L, and the working tank can generally hold about 1200 liters of alkali liquor.

[0038] See Figure 1 、 2 The present invention provides a method for controlling the alkali concentration of dyeing and finishing equipment. The dyeing and finishing equipment includes a working tank 1 for impregnating alkali liquor, a preparation tank 2 for preparing alkali liquor, and an alkali concentration detection mechanism 3 for detecting the alkali liquor concentration in the working tank 1 and the preparation tank 2. The control method includes the following steps:

[0039] (1) The alkali concentration detection mechanism 3 detects the real-time concentration value P of the alkali liquor in the working tank 1 i , and compares the real-time concentration value P i with the process-set alkali liquor concentration value C i ,

[0040] (1a) If P i < C i - ΔW, where ΔW is the allowable concentration error value, and ΔW ≥ 0;

[0041] (1b) Configure alkali liquor with a concentration of C j in the preparation tank 2, and C j = (C i + ΔK), where ΔK is the alkali concentration adjustment increment, and ΔK > 0;

[0042] (1c) Add the alkali liquor in the preparation tank 2 to the working tank 1;

[0043] (1d) The alkali concentration detection mechanism 3 detects the real-time concentration value P of the alkali liquor in the working tank 1 after step (1c) j+（n-1） , if P j+（n-1） < C i - ΔW, the preparation tank 2 configures alkali liquor with a concentration of C j+n = C j+（n-1） + ΔK, n is a positive integer, and return to step (1c) to execute sequentially. When step (1c) and (1d) are executed for the first time, n takes the value of 1. When executed for the second time, n takes the value of 2, and so on, until C i - ΔW ≤ Pj+（n-1） ≤ C i When it is +ΔW, return to step (1) and execute sequentially.

[0044] As a preferred embodiment of the present invention, after step (1),

[0045] (2a) If the P i > C i +ΔW, where ΔW is the allowable concentration error value and ΔW≥0;

[0046] (2b) Configure the lye with a concentration of C f in the preparation tank 2, and C f = (C i - ΔK), where ΔK is the lye concentration adjustment increment and ΔK>0;

[0047] (2c) Add the lye in the preparation tank 2 to the working tank 1;

[0048] (2d) The lye concentration detection mechanism 3 detects the real-time concentration value P f+（n-1） of the lye in the working tank 1 after step (2c). If P f+（n-1） > C i +ΔW, configure the lye with a concentration of C f+n = C f+（n-1） - ΔK in the preparation tank 2. n is a positive integer. Return to step (2c) and execute sequentially. When step (2c) and (2d) are executed for the first time, n is 1. When executed for the second time, n is 2, and so on, until C i - ΔW≤P f+（n-1） ≤ C i +ΔW, return to step (1) and execute sequentially.

[0049] As another preferred embodiment of the present invention, after step (1),

[0050] (3a) If the P i > C i +ΔW, where ΔW is the allowable concentration error value and ΔW≥0;

[0051] (3b) According to the P i , C i and the real-time lye volume V in the working tank 1, calculate and discharge the lye volume △V in the working tank 1, and △V = V×(P i - C i )÷P i ;

[0052] (3c) Add water equal to △V to the working tank 1 to make the lye concentration within the range of C i ±ΔW, and return to step (1) and execute sequentially.

[0053] As a preferred embodiment of the present invention, 0.1%C i ≤ΔW≤10%C i , 1%C i ≤ΔK≤30%C i .

[0054] As a preferred embodiment of the present invention, refer to Figure 1 , 2 , the alkali concentration detection mechanism 3 includes an alkali solution detection flow cell 3-2 provided with an alkali solution concentration sensor 3-1. The shape of the alkali solution detection flow cell 3-2 can be tank-shaped, barrel-shaped, etc. The working tank 1 is connected to the alkali solution detection flow cell 3-2 through a first pipeline 1-1, and the preparation tank 2 is connected to the alkali solution detection flow cell 3-2 through a second pipeline 2-1. A first control valve 1-2, such as an electrically controlled or pneumatically controlled stop valve, is provided on the first pipeline 1-1, and a second control valve 2-2, such as an electrically controlled or pneumatically controlled stop valve, is provided on the second pipeline 2-1. The alkali concentration detection mechanism 3 preferably further includes a waste liquid discharge pipeline 3-3 and a waste liquid control valve 3-4, a cleaning water pipe 3-5 and a cleaning water control valve 3-6. The alkali solution concentration sensor 3-1, the first control valve 1-2, the second control valve 2-2, the waste liquid control valve 3-4, and the cleaning water control valve 3-6 are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller through wired or wireless signals. The electric controller can adopt a digital controller with a human-machine interface, such as a DDC digital controller, an embedded control system, an industrial control computer, etc. The electric controller is not shown in the figure. During operation, the alkali concentration detection mechanism 3 adopts a time-division multiplexing method, that is, when it is necessary to detect the real-time concentration value of the alkali solution in the working tank 1, the electric controller opens the first control valve 1-2, sends the alkali solution in the working tank 1 into the alkali solution detection flow cell 3-2, and obtains the real-time concentration value through on-line detection by the alkali solution concentration sensor 3-1. After the detection is completed, the waste liquid is preferably discharged from the alkali solution detection flow cell 3-2 through the waste liquid discharge pipeline 3-3 and the waste liquid control valve 3-4, and then the first control valve 1-2 is closed. When it is necessary to detect the real-time concentration value of the alkali solution in the preparation tank 2, the electric controller opens the second control valve 2-2, sends the alkali solution in the preparation tank 2 into the alkali solution detection flow cell 3-2, and obtains the real-time concentration value through on-line detection by the alkali solution concentration sensor 3-1. After the detection is completed, the waste liquid is preferably discharged from the alkali solution detection flow cell 3-2 through the waste liquid discharge pipeline 3-3 and the waste liquid control valve 3-4, and then the second control valve 2-2 is closed. After each detection of the alkali concentration detection mechanism 3, the alkali concentration detection mechanism 3 is preferably automatically cleaned through the cleaning water pipe 3-5 and the cleaning water control valve 3-6.

[0055] As another preferred embodiment of the present invention, the alkali concentration detection mechanism 3 includes a first alkali solution concentration sensor and a second alkali solution concentration sensor; the first alkali solution concentration sensor is used to detect the alkali solution concentration in the working tank 1, and the second alkali solution concentration sensor is used to detect the alkali solution concentration in the preparation tank 2. The first and second alkali solution concentration sensors are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller through wired or wireless signals. The first alkali solution concentration sensor and the second alkali solution concentration sensor are not shown in the figure. During operation, when it is necessary to detect the real-time concentration value of the alkali solution in the working tank 1, the first alkali solution concentration sensor is used to perform on-line detection to obtain the real-time concentration value, and the data is transmitted to the electric controller. When it is necessary to detect the real-time concentration value of the alkali solution in the preparation tank 2, the second alkali solution concentration sensor is used to perform on-line detection to obtain the real-time concentration value, and the data is transmitted to the electric controller.

[0056] As a preferred embodiment of the present invention, the dyeing and finishing equipment is provided with a first liquid level sensor 4 and a second liquid level sensor 5; the first liquid level sensor 4 is used to detect the alkali liquid level in the working tank 1, and the second liquid level sensor 5 is used to detect the alkali liquid level in the preparation tank 2. The first and second liquid level sensors 4 and 5 are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller through wired or wireless signals. During operation, the alkali liquid level in the working tank 1 is detected by the first liquid level sensor 4, and the data is transmitted to the electric controller. When the alkali liquid level in the working tank 1 is lower than the process-specified liquid level, the electric controller controls the metering pump 7a or the flow control valve 7b to add the alkali solution with a concentration of C in step 1d i -ΔW≤P j+（n-1） ≤C i +ΔW from the preparation tank 2 to the working tank 1 until the alkali liquid level reaches the process-specified liquid level or within its allowable range; and by detecting the alkali liquid level in the working tank 1 through the first liquid level sensor 4, the real-time alkali liquid volume V of the working tank 1 can be obtained. The second liquid level sensor 5 detects the alkali liquid level in the preparation tank 2, and the data is transmitted to the electric controller. When the alkali liquid level in the preparation tank 2 is lower than the set liquid level, the electric controller controls the alkali inlet control valve 2-5 and the water inlet control valve 2-6 to prepare the alkali solution with the current concentration, so that the liquid level in the preparation tank 2 is always at the set liquid level or within its allowable range.

[0057] As a preferred embodiment of the present invention, during operation, since the fabric continuously takes away a certain amount of the working liquid, the system liquid supplement is set to continuous operation. The electric controller always controls the metering pump 7a or the flow control valve 7b to add the alkali solution with a concentration of C in step (1d) i -ΔW≤P j+（n-1） ≤C i +ΔW from the preparation tank 2 to the working tank 1 in excess of the fabric carrying amount. The overflowing alkali solution in the working tank 1 flows back to the recovery tank, and the preparation tank 2 also continuously prepares the alkali solution with a concentration of C i -ΔW≤P j+（n-1）≤C i The lye with +ΔW, and ensure that its liquid level is always within the specified liquid level of the lye in the preparation tank or within its allowable range.

[0058] As a preferred embodiment of the present invention, refer to Figure 1 、 2 , the preparation tank 2 is provided with a lye input pipe 2-3 and a water inlet pipe 2-4. The lye input pipe 2-3 is provided with an inlet lye control valve pipe 2-5, such as an electrically controlled or pneumatically controlled stop valve. The water inlet pipe 2-4 is provided with a water inlet control valve 2-6, such as an electrically controlled or pneumatically controlled stop valve. The inlet lye control valve 2-5 and the water inlet control valve 2-6 are controlled by the electric controller of the dyeing and finishing equipment or an independently provided electric controller. In terms of electrical connection, the inlet lye control valve 2-5 and the water inlet control valve 2-6 are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller through wired or wireless signals. During operation, according to actual needs, the electric controller controls the opening and closing and the opening degree of the inlet lye control valve 2-5 and the water inlet control valve 2-6, and prepares lye with a concentration that meets the actual needs in the preparation tank 2. Preferably, ensure that the liquid level in the preparation tank 2 is always within the set liquid level or its allowable range.

[0059] As a preferred embodiment of the present invention, refer to Figure 1 、 2 , a connecting pipe 6 is provided between the working tank 1 and the preparation tank 2. The connecting pipe 6 is provided with a control pump / valve, and the control pump / valve includes Figure 1 the metering pump 7a shown in Figure 2 the flow control valve 7b shown in

[0060] or a liquid metering pump or composed of a flow meter and an electric control valve, etc. The control pump / valve is controlled by the electric controller of the dyeing and finishing equipment or an independently provided electric controller; in terms of electrical connection, the control pump / valve is connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller through wired or wireless signals. Figure 1 、 2 , the working tank 1 is provided with a fresh water addition pipe 7c and a lye discharge pipe 8. The fresh water addition pipe 7c is provided with a water addition control valve 7d, and the lye discharge pipe 8 is provided with a lye discharge control valve 9. The water addition control valve 7d and the lye discharge control valve 9 are controlled by the electric controller of the dyeing and finishing equipment or an independently provided electric controller. In terms of electrical connection, the water addition control valve 7d and the lye discharge control valve 9 are connected to the electric controller of the dyeing and finishing equipment or an independently provided electric controller through wired or wireless signals.

[0061] As a preferred working process of the present invention, refer to Figure 1 、 2, the control method includes: (1) The electric controller opens the first control valve 1-2, and sends the lye in the working tank 1 during the operation of the fabric 10 into the lye detection flow-through cell 3-2 through the first pipeline 1-1. The lye concentration sensor 3-1 detects the real-time concentration value P of the lye in the working tank 1 i and transmits the data to the electric controller. At the same time, the electric controller closes the first control valve 1-2 and drains the waste liquid in the lye detection flow-through cell 3-2. The electric controller transmits the real-time concentration value P i to be compared with the process-set lye concentration value C i ;

[0062] (1a) If the P i < C i -ΔW, preferably 0.1%C i ≤ΔW≤10%C i ;

[0063] (1b) The electric controller controls the opening and closing and the opening degree of the lye inlet control valve 2-5 and the water inlet control valve 2-6, and configures lye in the preparation tank 2. During the preparation process, the electric controller opens the second control valve 2-2, and sends the lye configured in the preparation tank 2 into the lye detection flow-through cell 3-2 through the second pipeline 2-1. The lye concentration sensor 3-1 performs on-line detection to obtain lye with a concentration of C j , C j =(C i +ΔK), preferably 1%C i ≤ΔK≤30%C i . After the preparation is completed, the electric controller closes the second control valve 2-2, opens the waste liquid control valve 3-4 and drains the waste liquid in the lye detection flow-through cell after 3-2, opens the cleaning water control valve 3-6, injects clean water into the lye detection flow-through cell 3-2 for cleaning, and after the cleaning is completed, closes the cleaning water control valve 3-6 and closes the waste liquid control valve 3-4;

[0064] (1c) The electric controller opens the metering pump 7a shown in Figure 1 or the flow control valve 7b shown in Figure 2 , and preferably adds the lye in the preparation tank 2 to the working tank 1 quantitatively, such as 5 liters or 8 liters or 15 liters, etc., or all through the connecting pipe 6. The liquid outlet 6-1 of the connecting pipe 6 is preferably a conventional toothed overflow trough full-width uniform liquid outlet;

[0065] (1d) The electric controller opens the first control valve 1-2, and sends the lye in the working tank 1 after step (1c) into the lye detection flow-through cell 3-2 through the first pipeline 1-1. The lye concentration sensor 3-1 detects the real-time concentration value P of the lye in the working tank 1 after step (1c) j+（n-1）, and transfer the data to the electric controller. Meanwhile, the electric controller closes the first control valve 1-2, opens the waste liquid control valve 3-4 to drain the waste liquid in the caustic soda detection flow cell 3-2, and then opens the cleaning water control valve 3-6. After injecting clean water into the caustic soda detection flow cell 3-2 for cleaning, the cleaning water control valve 3-6 and the waste liquid control valve 3-4 are closed. At the same time, the electric controller transmits the real-time concentration value P j+（n-1） to be compared with the set concentration value C of the caustic soda process i . If P j+（n-1） < C i -ΔW, the electric controller controls the opening and closing and the opening degree of the caustic soda inlet control valve 2-5 and the water inlet control valve 2-6, and prepares caustic soda with a concentration of C j+n = C j+（n-1） +ΔK in the preparation tank 2. The preparation process is the same as that in step (1b) and will not be elaborated here. n is a positive integer. Return to step (1c) and execute sequentially. When step (1c) and (1d) are executed for the first time, n takes the value of 1. When executed for the second time, n takes the value of 2, and so on, until C i -ΔW ≤ P j+（n-1） ≤ C i +ΔW, return to step (1) and execute sequentially. In this step, ΔK can take a certain value. For example, each time step (1c) and (1d) are executed, ΔK takes 4% C i ; ΔK can also take a variable value, taking the difference between the real-time concentration value of the caustic soda in the working tank and the set concentration value C i each time as the increment of the caustic soda concentration in the preparation tank; it can also decrease sequentially with each execution of step (1c) and (1d). For example, when executed for the first time, ΔK takes 6% C i , and when executed for the second time, ΔK takes 5.5% C i , and so on; or according to the changing trend of the caustic soda concentration in the working tank approaching the set concentration value C i , the value of ΔK decreases in a timely manner. For example, when executed for the first time, ΔK takes 8% C i , when executed for the second time, the value of ΔK remains unchanged, or when executed for the second time, ΔK takes 3% C i , and when executed for the third time, ΔK takes 2.5% C i , etc. That is, the electric controller changes the value of ΔK in a timely manner according to the real-time concentration value in the working tank and its changing trend by a conventional built-in algorithm

[0066] Since the fabric 10 runs through caustic soda padding / impregnation in the working tank 1, the fabric fibers swell, the solute of the caustic soda penetrates into the interior of the fibers and between the inner-layer fibers. The fabric through caustic soda padding / impregnation will absorb caustic soda, and the acidic gas in the air will also consume caustic soda. These disturbances directly cause the concentration of the caustic soda in the working tank 1 to gradually decrease. Therefore, usually, the above-mentioned P i < C i-ΔW condition.

[0067] The electric controller compares the real-time concentration value P i with the set concentration value C of the lye process i and

[0068] (2a) If the P i > C i +ΔW, preferably 0.1%C i ≤ΔW≤10%C i , the following steps can be taken;

[0069] (2b) The electric controller controls the opening and closing and the opening degree of the lye inlet control valve 2-5 and the water inlet control valve 2-6, configures lye in the preparation tank 2. During the preparation process, the electric controller opens the second control valve 2-2, sends the lye configured in the preparation tank 2 into the lye detection flow-through cell 3-2 through the second pipeline 2-1, and the lye concentration sensor 3-1 performs on-line detection to obtain lye with a concentration of C f , C f =(C i -ΔK), preferably 1%C i ≤ΔK≤30%C i . After the preparation is completed, the electric controller closes the second control valve 2-2, opens the waste liquid control valve 3-4 and drains the waste liquid in the lye detection flow-through cell 3-2, then opens the cleaning water control valve 3-6, injects clean water into the lye detection flow-through cell 3-2 for cleaning. After the cleaning is completed, closes the cleaning water control valve 3-6 and the waste liquid control valve 3-4;

[0070] (2c) The electric controller opens the Figure 1 shown metering pump 7a or Figure 2 shown flow control valve 7b, and preferably quantitatively adds, such as 5 liters or 8 liters or 15 liters, etc., or all of the lye in the preparation tank 2 to the working tank 1 through the connecting pipe 6. The liquid outlet 6-1 of the connecting pipe 6 is preferably a conventional toothed overflow tank full-width uniform liquid outlet;

[0071] (2d) The electric controller opens the first control valve 1-2, sends the lye in the working tank 1 after step (2c) into the lye detection flow-through cell 3-2 through the first pipeline 1-1, and the lye concentration sensor 3-1 detects the real-time concentration value P of the lye in the working tank 1 after step (2c) f+（n-1） , and transmits the data to the electric controller. At the same time, the electric controller closes the first control valve 1-2, opens the waste liquid control valve 3-4 and drains the waste liquid in the lye detection flow-through cell 3-2, then opens the cleaning water control valve 3-6, injects clean water into the lye detection flow-through cell 3-2 for cleaning. After the cleaning is completed, closes the cleaning water control valve 3-6 and the waste liquid control valve 3-4. At the same time, the electric controller compares the real-time concentration value P f+（n-1） with the set concentration value C of the lye processi In comparison, if P f+（n-1） > C i + ΔW, the electric controller controls the opening and closing and the opening degree of the caustic inlet control valve 2-5 and the water inlet control valve 2-6, and the preparation tank 2 prepares the caustic solution with a concentration of C f+n = C f+（n-1） - ΔK. The preparation process is the same as that in step (2b) and will not be elaborated here. n is a positive integer. Return to step (2c) and execute sequentially. When step (2c) and (2d) are executed for the first time, n takes the value of 1. When executed for the second time, n takes the value of 2, and so on, until C i - ΔW ≤ P f+（n-1） ≤ C i + ΔW, return to step (1) and execute sequentially. In this step, ΔK can take a certain value. For example, each time step (2c) and (2d) are executed, ΔK takes 4% C i ; ΔK can also take a variable value, and each time the difference between the real-time concentration value of the caustic solution in the working tank and the process-set concentration value C i is taken as the increment of the caustic solution concentration in the preparation tank; it can also decrease sequentially with each execution of step (2c) and (2d). For example, when executed for the first time, ΔK takes 6% C i , when executed for the second time, ΔK takes 5.5% C i , and so on; or according to the changing trend of the caustic solution concentration in the working tank approaching the process-set concentration value C i , the value of ΔK decreases in a timely manner. For example, when executed for the first time, ΔK takes 8% C i , when executed for the second time, the value of ΔK remains unchanged, or when executed for the second time, ΔK takes 3% C i , when executed for the third time, ΔK takes 2.5% C i etc. That is, the electric controller changes the value of ΔK in a timely manner according to the real-time concentration value in the working tank and its changing trend by a conventional built-in algorithm.

[0072] The electric controller compares the real-time concentration value P i with the process-set concentration value C of the caustic solution i .

[0073] (3a) If the P i > C i + ΔW, preferably 0.1% C i ≤ ΔW ≤ 10% C i , the following steps can also be taken;

[0074] (3b) The first liquid level sensor 4 detects the caustic solution level in the working tank 1 and transmits the data to the electric controller. The electric controller calculates and obtains the real-time caustic solution volume V in the working tank 1. The electric controller calculates according to the P i , C iAnd the real-time caustic solution volume V in the working tank 1 is calculated, and the caustic solution volume ΔV in the working tank 1 is discharged through the caustic solution discharge pipe 8 and the caustic discharge control valve 9. ΔV = V×(P i - C i )÷P i , and then the caustic discharge control valve 9 is closed;

[0075] (3c) The electric controller opens the water addition control valve 7d to control the working tank 1 to add water equal to the amount of ΔV, so that the caustic concentration is within the range of C i ±ΔW, and return to step (1) to execute sequentially.

[0076] Through testing, the present invention has high precision in adjusting the caustic solution concentration, the caustic and water are evenly fused, and the caustic solution concentration in the working tank is always within the process-set concentration value range, achieving good results.

Claims

1. A method for controlling the alkali concentration of a dyeing and finishing equipment, the dyeing and finishing equipment including a working tank for impregnating alkali liquor, characterized in that, There is also a preparation tank for preparing the alkaline solution and an alkaline concentration detection mechanism for detecting the alkaline solution concentration in the working tank and the preparation tank. The control method includes the following steps: (1) The alkaline concentration detection mechanism detects the real-time concentration value Pi of the alkaline solution in the working tank, and compares the real-time concentration value Pi with the set concentration value Ci of the alkaline solution process. (1a) If Pi < Ci - ΔW, where ΔW is the allowable concentration error value and ΔW ≥ 0; (1b) Prepare an alkaline solution with a concentration of Cj in the preparation tank, where Cj = (Ci + ΔK), ΔK is the alkaline concentration adjustment increment and ΔK > 0; (1c) Add the alkaline solution in the preparation tank to the working tank; (1d) The alkaline concentration detection mechanism detects the real-time concentration value Pj+(n - 1) of the alkaline solution in the working tank after step (1c). If Pj+(n - 1) < Ci - ΔW, prepare an alkaline solution with a concentration of Cj+n = Cj+(n - 1) + ΔK in the preparation tank. n is a positive integer, and return to step (1c) to execute sequentially. When step (1c) and (1d) are executed for the first time, n takes the value of 1. When executed for the second time, n takes the value of 2, and so on, until Ci - ΔW ≤ Pj+(n - 1) ≤ Ci + ΔW, then return to step (1) to execute sequentially; Among them, 1%Ci ≤ ΔK ≤ 30%Ci. During the process of repeatedly executing step (1d), determine the value of ΔK according to the real-time concentration value of the working tank and its change trend.

2. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1, wherein: After step (1), (2a) If Pi > Ci + ΔW, where ΔW is the allowable concentration error value and ΔW ≥ 0; (2b) Prepare an alkaline solution with a concentration of Cf in the preparation tank, where Cf = (Ci - ΔK), ΔK is the alkaline concentration adjustment increment and ΔK > 0; (2c) Add the alkaline solution in the preparation tank to the working tank; (2d) The alkaline concentration detection mechanism detects the real-time concentration value Pf+(n - 1) of the alkaline solution in the working tank after step (2c). If Pf+(n - 1) > Ci + ΔW, prepare an alkaline solution with a concentration of Cf+n = Cf+(n - 1) - ΔK in the preparation tank. n is a positive integer, and return to step (2c) to execute sequentially. When step (2c) and (2d) are executed for the first time, n takes the value of 1. When executed for the second time, n takes the value of 2, and so on, until Ci - ΔW ≤ Pf+(n - 1) ≤ Ci + ΔW, then return to step (1) to execute sequentially.

3. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1, wherein: After step (1), (3a) If Pi > Ci + ΔW, where ΔW is the allowable concentration error value and ΔW ≥ 0; (3b) Calculate and discharge the volume of the alkaline solution in the working tank △V according to Pi, Ci and the real-time volume V of the alkaline solution in the working tank, where △V = V×(Pi - Ci)÷Pi; (3c) Add water equal to △V to the working tank to make the alkaline concentration within the range of Ci ± ΔW, and return to step (1) to execute sequentially.

4. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1 or 2 or 3, characterized in that: 0.1%Ci ≤ ΔW ≤ 10%Ci.

5. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1 or 2 or 3, characterized in that: The alkali concentration detection mechanism includes an alkali solution detection flow cell provided with an alkali solution concentration sensor. The working tank is connected to the alkali solution detection flow cell through a first pipeline, and the preparation tank is connected to the alkali solution detection flow cell through a second pipeline. The first pipeline is provided with a first control valve, and the second pipeline is provided with a second control valve. The alkali solution concentration sensor, the first control valve, and the second control valve are connected to the electrical controller of the dyeing and finishing equipment or an independently provided electrical controller.

6. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1 or 2 or 3, characterized in that: The alkali concentration detection mechanism includes a first alkali solution concentration sensor and a second alkali solution concentration sensor; the first alkali solution concentration sensor is used to detect the alkali solution concentration in the working tank, the second alkali solution concentration sensor is used to detect the alkali solution concentration in the preparation tank, and the first and second alkali solution concentration sensors are connected to the electrical controller of the dyeing and finishing equipment or an independently provided electrical controller.

7. The method for controlling the alkali concentration of a dyeing and finishing equipment according to claim 1 or 2 or 3, characterized in that: The dyeing and finishing equipment is provided with a first liquid level sensor and a second liquid level sensor; the first liquid level sensor is used to detect the alkali solution level in the working tank, the second liquid level sensor is used to detect the alkali solution level in the preparation tank, and the first and second liquid level sensors are connected to the electrical controller of the dyeing and finishing equipment or an independently provided electrical controller.

8. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1 or 2 or 3, characterized in that: The preparation tank is provided with an alkali solution input pipe and a water inlet pipe. The alkali solution input pipe is provided with an alkali inlet control valve, and the water inlet pipe is provided with a water inlet control valve. The alkali inlet control valve and the water inlet control valve are controlled by the electrical controller of the dyeing and finishing equipment or an independently provided electrical controller.

9. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1 or 2 or 3, characterized in that: A connecting pipe is provided between the working tank and the preparation tank, and the connecting pipe is provided with a control pump / valve, which is controlled by the electrical controller of the dyeing and finishing equipment or an independently provided electrical controller.

10. The method for controlling the alkali concentration of the dyeing and finishing equipment according to claim 1 or 2 or 3, characterized in that: The working tank is provided with a fresh water addition pipe and an alkali solution discharge pipe. The fresh water addition pipe is provided with a water addition control valve, and the alkali solution discharge pipe is provided with an alkali discharge control valve. The water addition control valve and the alkali discharge control valve are controlled by the electrical controller of the dyeing and finishing equipment or an independently provided electrical controller.

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