Titration acid adding structure and dyeing machine thereof

Abstract

The invention discloses a titration acid adding structure and a dyeing machine thereof, relates to the technical field of dyeing and finishing equipment, and solves the technical defects that the acid control mode of the traditional dyeing machine cannot accurately control the pH value, or two sets of central acid adding barrels are needed, manual dilution is needed, the occupied area is large, the operation is inconvenient, automatic control cannot be realized and the like. The bottom of the self-flowing acid storage barrel is connected with an acid adding valve; a nozzle of the acid adding valve is internally provided with a replaceable throttling joint with different hole diameters; a backflow pipeline is further arranged on the feeding barrel; the outlet of the material pump is also connected with a filling pipeline of the main cylinder; and a quantitative follow-up valve is arranged on the filling pipeline. A user does not need to prepare one more diluted acid barrel, dilution is not needed, and full-process automation of acid control can be truly achieved on the premise that the acid adding control precision is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of dyeing and finishing equipment technology, specifically to structural improvements of dyeing machines employing titration and acid addition. Background Technology

[0002] There are two main methods for acid control in traditional dyeing machines: Method 1 involves injecting acid into the main pump inlet using a metering pump. However, since the pH value is extremely sensitive at 7, the metering pump cannot accurately measure the acid, often resulting in significant pH over-adjustment. This can lead to excessively rapid coloring and uneven coloring, causing quality problems. Method 2 involves installing an acid-adding valve at the pump inlet of the feeding tank. To prevent excessive acid addition at around 7, two acid-adding valves are required: one for raw acid (such as 98% glacial acetic acid) and the other for dilute acid (such as 50% glacial acetic acid). While this method effectively addresses pH sensitivity, it requires the user to prepare two central acid-adding tanks, and the dilute acid tank needs to be manually opened, increasing the workload of operators, occupying space, and failing to achieve fully automatic acid control. Summary of the Invention

[0003] In summary, the purpose of this invention is to address the shortcomings of traditional dyeing machines, such as the inability to accurately control pH value through acid control methods, the need for two central acid tanks, the requirement for manual dilution, the large space required, the inconvenience of operation, and the inability to achieve automatic control. Therefore, this invention proposes a titration acid addition structure and its dyeing machine.

[0004] To address the shortcomings of the technology proposed in this invention, the following technical solution is adopted: A titration acid addition structure is characterized by comprising: a gravity-flow acid storage tank and a feeding tank; the bottom of the gravity-flow acid storage tank is connected to an acid addition valve for controlling the titration acid addition from the gravity-flow acid storage tank to the feeding tank; the nozzle of the acid addition valve is provided with a throttling valve of different orifice diameters; the feeding tank is also provided with a reflux pipe for returning the dye liquor in the main cylinder, and a reflux valve is provided on the reflux pipe; a circulation mixing pipeline is provided between the bottom and the side wall of the feeding tank, and a feed pump and a mixing valve are connected in series on the circulation mixing pipeline; the outlet of the feed pump is also connected to the main cylinder's injection pipeline, and a quantitative follow-up valve is provided on the injection pipeline.

[0005] The technical features that further define the present invention include: The reflux valve includes a normal temperature reflux valve and a high temperature reflux valve, which are respectively installed on the first reflux sub-pipe and the second reflux sub-pipe. The first reflux sub-pipe and the second reflux sub-pipe are connected in parallel, and the second reflux sub-pipe is also equipped with a first cooler.

[0006] The filling pipeline is also equipped with a fast filling control valve connected in parallel with the metering follow-up valve.

[0007] The present invention discloses a dyeing machine, comprising: a main cylinder, a main pump, a heat exchanger, and an acid addition control system; the main pump and the heat exchanger are connected in series on a heating circulation pipe connected to the main cylinder; it also includes the aforementioned titration acid addition structure, wherein the reflux pipe is connected to the heating circulation pipe to return the dye liquor in the main cylinder to the feeding tank; the quantitative follow-up valve is connected to the main cylinder to continuously add the dye liquor from the feeding tank to the main cylinder; a pH sampling pipe is also provided on the heating circulation pipe in the direction of the main pump outlet, and a pH sampling valve, a second cooler, and a pH sensor are provided on the pH sampling pipe; the pH sensor is located after the second cooler; the pH sensor, the heating follow-up valve of the heat exchanger, and the acid addition valve are respectively connected to the acid addition controller.

[0008] The method by which the controller controls the acid adding valve to add acid is as follows: Once the function is running normally, the pH sampling valve is opened to sample the dye solution in the main tank, obtaining the initial pH value of the dye solution in the main tank. At the same time, the acid addition controller collects the initial temperature of the dye solution in the main tank through the dye solution temperature sensor, and then uses the dye solution temperature sensor to collect the dye solution temperature in the main tank in real time. After the dye solution temperature reaches the preset endpoint temperature, the pH change curve with temperature is determined based on the heating time and the pH value at the endpoint temperature. The acid addition controller controls the opening and closing of the acid addition valve through the PID control principle based on the pH change curve with temperature and the set heat exchanger heating rate parameters, so as to achieve the consistency between the actual pH value and the control value.

[0009] The pH sampling valve includes a sampling inlet valve located at the inlet of the pH sampling pipeline and a sampling outlet valve located at the outlet of the pH sampling pipeline. A flushing valve is also provided between the sampling inlet valve and the second cooler, and a drain valve is provided between the sampling outlet valve and the pH sensor.

[0010] The beneficial effects of this invention are as follows: This invention adds an acid valve to the bottom of the self-flowing acid storage tank. The nozzle of the acid valve is equipped with throttling plates of different orifice diameters according to the machine's load capacity, which can effectively prevent excessive acid addition. The raw acid in the self-flowing acid storage tank is dripped into the feeding tank through the acid valve. During the acid addition process, the feeding tank also returns the dye liquor in the main cylinder through a return pipe. The raw acid added to the feeding tank is diluted by the returned dye liquor, and after dilution, it is injected into the main cylinder. This achieves simultaneous return and injection during acid addition. The feeding tank also has a dilution function, eliminating the need for an additional dedicated dilute acid tank. Furthermore, the dripping state of the acid valve can be observed visually, which is something that traditional method 2 cannot achieve. This invention can completely simulate the traditional dilute acid agent feeding method, reproducing the pH value at different temperature points, fundamentally solving the high cost problem of dilute acid agents, and bringing convenience to customers' large-scale industrial production. This invention is an improvement on the traditional method 2, which only requires one raw acid titration valve and one raw acid tank. The raw acid tank can be replenished regularly by tank trucks in chemical plants. Users do not need to prepare an additional dilute acid tank or dilute it. It can truly achieve full automation of acid control while ensuring the accuracy of acid control. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the dyeing machine system structure of the present invention; Figure 2 This is a schematic diagram of the acid addition valve structure of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the nozzle portion of the acid addition valve of the present invention. Detailed Implementation

[0012] The structure of the present invention will be further described below with reference to the accompanying drawings and preferred embodiments.

[0013] Reference Figures 1 to 3 As shown, the titration acid addition structure disclosed in this invention can be applied to various dyeing machines, such as overflow machines, air flow machines, gas-liquid machines, warp beam machines, or yarn dyeing machines, to realize the titration acid control function. It can also be applied to dyeing functions such as nylon acid dyes to replace dilute acid dyes.

[0014] The titration acid addition structure of this invention specifically includes: a self-flowing acid storage tank and a feeding tank; when the titration acid addition structure of this invention is applied to the titration acid control function of various dyeing machines, the self-flowing acid storage tank is used to store raw acid, such as 98% glacial acetic acid; the bottom of the self-flowing acid storage tank is connected to an acid addition valve 4 for controlling the titration acid addition from the self-flowing acid storage tank to the feeding tank; the nozzle of the acid addition valve is equipped with a throttling device 6 with replaceable orifice diameters; throttling devices 6 with different orifice diameters are configured according to the machine's load capacity.

[0015] To dilute the acid in the self-flowing acid storage tank, the feeding tank is equipped with a reflux pipe for returning the dye liquor to the main cylinder. A reflux valve is installed on the reflux pipe. When the reflux valve is opened, the dye liquor in the main cylinder can flow back to the feeding tank under the action of the main pump of the dyeing machine. The acid concentration is reduced in the feeding tank by the refluxed dye liquor. To prevent the high-temperature dye liquor in the main cylinder from flowing back into the feeding tank, the reflux valve of this invention includes a normal temperature reflux valve and a high-temperature reflux valve. The normal temperature reflux valve and the high-temperature reflux valve are respectively installed on the first reflux sub-pipe and the second reflux sub-pipe, which are connected in parallel. A first cooler is also installed on the second reflux sub-pipe. In the specific implementation process, if the main cylinder temperature exceeds 80 degrees during reflux, the normal temperature reflux valve is closed, and the high temperature reflux valve and the coolant valve of the first cooler are opened. The temperature is automatically adjusted by the temperature sensing needle behind the high temperature flow valve to ensure that the refluxed dye solution does not exceed the preset normal temperature, such as 25 degrees Celsius.

[0016] To improve the uniformity of acid concentration in the dye liquor injected into the main cylinder, a circulating mixing pipeline is installed between the bottom and side wall of the feeding tank. A feed pump and a mixing valve are connected in series on the circulating mixing pipeline. When the feed pump and mixing valve are turned on, the dye liquor in the feeding tank is mixed to dilute the dripping acid, reduce its concentration, and improve uniformity. The outlet of the feed pump is also connected to the main cylinder's injection pipeline, which is equipped with a metering follow-up valve. When the feeding tank adds titrated acetic acid to the main cylinder, the metering follow-up valve allows the feeding tank to simultaneously reflux and inject. During the circulating injection process, the opening of the metering follow-up valve can be controlled to ensure continuous injection and maintain the continuity of the injection.

[0017] In order to enable the rapid injection of dye liquor into the main cylinder through the feeding tank, the injection pipeline is also equipped with a rapid injection control valve connected in parallel with the quantitative follow-up valve.

[0018] This invention discloses a dyeing machine that, in addition to the existing main cylinder, main pump, heat exchanger, and acid addition control system, also includes the aforementioned titration and acid addition structure. The main pump and heat exchanger are connected in series on a heating circulation pipe connected to the main cylinder. Under the action of the main pump, the dye liquor in the main cylinder passes through the heat exchanger and exchanges heat with the medium flowing through the heat exchanger, thereby heating the dye liquor. The return pipe of this invention is also connected to the existing heating circulation pipe for returning the dye liquor in the main cylinder to the feeding tank; specifically, it can be connected between the main pump outlet and the heat exchanger, or located at the outlet of the heat exchanger. The quantitative follow-up valve is connected to the main cylinder for continuously adding the dye liquor from the feeding tank into the main cylinder; that is, the filling outlet of the titration and acid addition structure is connected to the main cylinder.

[0019] To accurately collect the pH value of the dye solution in the main tank, a pH sampling pipe is also installed on the heating circulation pipeline in the direction of the main pump outlet. The pH sampling pipe is equipped with a pH sampling valve, a second cooler, and a pH sensor; the pH sensor is located after the second cooler. The pH sensor, the heating follow-up valve of the heat exchanger, and the acid addition valve are respectively connected to the acid addition controller. To facilitate periodic cleaning of the pH sensor and improve pH accuracy, the pH sampling valve includes a sampling inlet valve at the inlet of the pH sampling pipe and a sampling outlet valve at the outlet of the pH sampling pipe. A flushing valve is also installed between the sampling inlet valve and the second cooler, and a drain valve is installed between the sampling outlet valve and the pH sensor. After simultaneously closing the sampling inlet valve and the sampling outlet valve, cleaning fluid can be introduced through the flushing valve to clean the second cooler and the pH sensor, and the wastewater is discharged through the drain valve.

[0020] The method for controlling the acid addition valve using the controller of this invention is as follows: Once the system is functioning normally, the pH sampling valve is opened to sample the dye solution in the main tank, obtaining the initial pH value. Simultaneously, the acid addition controller collects the initial temperature of the dye solution in the main tank via a dye solution temperature sensor. Subsequently, the dye solution temperature in the main tank is monitored in real-time by the dye solution temperature sensor. After the dye solution temperature reaches the preset endpoint temperature, the pH-temperature curve is determined based on the heating time and the pH value at the endpoint temperature. The acid addition controller, based on the pH-temperature curve and the set heat exchanger heating rate parameters, controls the opening and closing of the acid addition valve using PID control principles to ensure that the actual pH value matches the controlled value. In practice, multiple "acid control" steps can be programmed on the host computer, with each step setting different heating rates, endpoint temperatures, and endpoint pH values. This allows for segmented linear acid control, reproducing the pH-temperature curve of traditional dilute acid agents.

[0021] For example, the current acid control step is programmed as follows: heating rate 1℃ / min, endpoint temperature 60℃, endpoint pH 7. When the function is running normally, the pH sampling valve will open to sample the dye solution in the main tank to obtain the initial pH value, assuming it is 8. The dyeing machine's temperature control system will also sample the dye solution temperature to obtain the initial temperature, assuming it is 50℃. Since the endpoint temperature is 60℃, the total acid control time is: (60℃-50℃) / 1℃ / min = 10min. Therefore, the acid addition rate needs to be controlled at: (8-7) / 10min. =0.1 / min. After sampling, the controller program will control the opening of the heat exchanger's heating follow-up valve according to the set heating rate, and at the same time open the feed tank reflux valve. When the reflux liquid level reaches the predetermined value, the feed pump and mixing valve will be turned on to mix the liquid in the feed tank, so as to dilute the acid, reduce the concentration and improve the uniformity. Then the metering follow-up valve of the feed tank will be opened, so that the feed tank can inject while refluxing, so that the titrated acetic acid can be added to the main cylinder. During the circulation injection process, the opening of the metering follow-up valve will be controlled as much as possible to prevent the injection from being interrupted, so as to maintain the continuity of injection. At the same time, the opening time of the reflux valve will be controlled according to the changes in the liquid in the feed tank, so as to maintain a stable liquid level in the feed tank. The feeding tank injects liquid into the main pump inlet via a feed pump. The main pump then circulates the liquid and performs pH sampling to collect the current pH value in the tank. During acid dripping control, the required pH control value is calculated based on the current temperature. The opening and closing of the acid adding valve is then controlled using PID control principles to ensure that the actual pH value matches the control value. To ensure the control accuracy of the acid adding valve and prevent overshoot, the control cycle of the acid adding valve is set to 8 seconds at the factory, and the maximum acid adding valve opening time is 1 second. These settings can be adjusted appropriately according to actual applications.

Claims

1. A titration acid addition structure, characterized in that... It includes: a gravity-flow acid storage tank and a feeding tank; the bottom of the gravity-flow acid storage tank is connected to an acid-adding valve that controls the titration of acid from the storage tank to the feeding tank; the nozzle of the acid-adding valve is equipped with a throttling valve with replaceable orifice diameters; the feeding tank is also equipped with a reflux pipe for returning the dye liquor in the main cylinder, and a reflux valve is installed on the reflux pipe; a circulation mixing pipeline is provided between the bottom and the side wall of the feeding tank, and a feed pump and a mixing valve are connected in series on the circulation mixing pipeline; the outlet of the feed pump is also connected to the main cylinder's filling pipeline, and a quantitative follow-up valve is installed on the filling pipeline.

2. The titration acid addition structure according to claim 1, characterized in that: The reflux valve includes a normal temperature reflux valve and a high temperature reflux valve, which are respectively installed on the first reflux sub-pipe and the second reflux sub-pipe. The first reflux sub-pipe and the second reflux sub-pipe are connected in parallel, and the second reflux sub-pipe is also equipped with a first cooler.

3. The titration acid addition structure according to claim 1, characterized in that: The filling pipeline is also equipped with a fast filling control valve connected in parallel with the metering follow-up valve.

4. A dyeing machine, comprising: a main cylinder, a main pump, a heat exchanger, and an acid addition control system; wherein the main pump and the heat exchanger are connected in series on a heating circulation pipe connected to the main cylinder; characterized in that: It also includes the titration acid addition structure as described in any one of claims 1-3, wherein the reflux pipe is connected to the heating circulation pipe to reflux the dye liquor in the main cylinder back to the feeding tank; the quantitative follow-up valve is connected to the main cylinder to continuously add the dye liquor from the feeding tank to the main cylinder; a pH sampling pipe is also provided on the heating circulation pipe in the direction of the main pump outlet, and a pH sampling valve, a second cooler and a pH sensor are provided on the pH sampling pipe; the pH sensor is located behind the second cooler; the pH sensor, the heating follow-up valve of the heat exchanger and the acid addition valve are respectively connected to the acid addition controller.

5. A dyeing machine according to claim 4, characterized in that: The method by which the controller controls the acid adding valve to add acid is as follows: Once the function is running normally, the pH sampling valve is opened to sample the dye solution in the main tank, obtaining the initial pH value of the dye solution in the main tank. At the same time, the acid addition controller collects the initial temperature of the dye solution in the main tank through the dye solution temperature sensor, and then uses the dye solution temperature sensor to collect the dye solution temperature in the main tank in real time. After the dye solution temperature reaches the preset endpoint temperature, the pH change curve with temperature is determined based on the heating time and the pH value at the endpoint temperature. The acid addition controller controls the opening and closing of the acid addition valve through the PID control principle based on the pH change curve with temperature and the set heat exchanger heating rate parameters, so as to achieve the consistency between the actual pH value and the control value.

6. A dyeing machine according to claim 4, characterized in that: The pH sampling valve includes a sampling inlet valve located at the inlet of the pH sampling pipeline and a sampling outlet valve located at the outlet of the pH sampling pipeline. A flushing valve is also provided between the sampling inlet valve and the second cooler, and a drain valve is provided between the sampling outlet valve and the pH sensor.

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