How to detect and control the alkali concentration of mercerizing machine?

First, take out a certain volume of NaOH solution, then determine the concentration of NaOH solution by manual titration, and compare it with the actual process concentration, and then manually supplement the original alkali. This method is slow, easy to make mistakes, obviously lags behind the production process, often affects the quality of the process and cannot meet the requirements of continuous production. The main principle of the system is to automatically and accurately compensate the parameters by detecting the density and temperature of alkali liquor on the straight roller mercerizing machine, so as to ensure high-precision detection results. Adopt advanced PLC control, touch screen technology and data communication technology; In addition, by digitally setting parameters, automatic alkali preparation and automatic alkali replenishment are realized, and it has the functions of automatic cleaning and protection. The system is mainly composed of measuring sensor and transmitter, controller, continuous regulating valve, on-off solenoid valve, power module and fluid pipeline. The basic idea of implementation is not to change the original pipeline of our mercerizing machine, but to lead out a pipeline from concentrated alkali, circulating alkali liquor and waterway official road respectively, to make adjustment pipeline, detection pipeline and cleaning pipeline respectively, and to connect them to its online automatic alkali concentration detection and control system, which is very convenient for overall installation. The working liquid is measured by sensor, and the supply of concentrated alkali is controlled by microcomputer. The light alkali adopts liquid level control valve switch, and when the liquid level drops, the light alkali liquor is automatically replenished. When the concentration is not enough, the control system adds an appropriate amount of concentrated alkali. The bivariate adjustment of concentrated alkali and weak alkali in the whole system is simple and practical. Before alkali preparation, determine the alkali concentration of the working solution and the concentration of the supplied concentrated alkali and weak alkali according to the process description. According to the proportioning ratio, the concentrated alkali is first added to the specified value of the scale of the alkali distribution tank, and then the diluted alkali is added to the specified amount. Start the alkali pump cycle for 15 minutes, then start the automatic alkali metering and distribution control system, then titrate and correct the digital display parameters, and start production after confirmation. In normal production, when changing varieties to adjust the alkali concentration, if the alkali concentration gradient is not large (within 60g/L), just input the process concentration parameters on the digital display screen of the automatic alkali metering and distribution control system. If the adjustment of alkali concentration gradient is too large when changing varieties, it is necessary to stop the machine through the guide cloth, pump the working liquid from the alkali preparation tank in proportion, add clean water to reduce the alkali concentration or add concentrated alkali to increase the alkali concentration, and start the alkali pump cycle 15 minutes for accurate correction before starting production. Calculation of economic benefits. After recovering light alkali from mercerizing machine, the consumption of concentrated alkali can be reduced by about one fifth. In normal production, the original dilute alkali concentration is generally 30g-50g/L, and a modified mercerizing machine can recover about 80g/L of dilute alkali for more than 30 tons every day. Actually, more than 50g/L of caustic soda can be recovered per liter, and 360g/L of concentrated alkali can be saved every day. According to the price per ton of 530 yuan, it can save 2 120 yuan per day, 46,640 yuan per month and 550,000 yuan per year. The whole system has strong anti-interference ability and can run stably and reliably even in harsh field environment such as printing and dyeing. The configuration and detection of concentrated NaOH become fast and simple, which not only realizes the automation of the production process, but also avoids the errors caused by manual operation, effectively ensures the product quality, improves the working conditions, reduces the production and management costs, saves considerable raw alkali consumption, reduces pollution discharge, ensures the reproducibility of the subsequent dyeing process parameters, directly improves the product grade and excellent product rate, and reduces the risk of making orders, thus greatly improving the profit rate.