阅读说明：本技术 葡萄糖结晶工艺中立式结晶机组多层级自动控温方法 (Multi-level automatic temperature control method for vertical crystallizer set in glucose crystallization process ) 是由 杨航 吴军辉 谢潭 成栋 沈战胜 刘丽 于 2020-07-03 设计创作，主要内容包括：本发明涉及葡萄糖结晶工艺中立式结晶机组多层级自动控温方法,立式结晶机组在初次进料达到稳定目标物位后,启动计时,在完成养晶过程后开始严格按照降温曲线进行降温。本发明的方法符合葡萄糖降温结晶控温曲线的多层级自动控温,在完成养晶过程后开始自动降温,实现每层降温的稳定和连续,更高效的完成初始化,产出也更稳定。(The invention relates to a multi-level automatic temperature control method for a vertical crystallizer set in a glucose crystallization process. The method of the invention conforms to the multi-level automatic temperature control of the temperature control curve of the glucose temperature reduction crystallization, starts automatic temperature reduction after the completion of the crystal growing process, realizes the stability and continuity of temperature reduction of each layer, completes initialization more efficiently, and has more stable output.)

1. The multi-level automatic temperature control method of the vertical crystallizer set in the glucose crystallization process is characterized in that:

and starting timing after the primary feeding of the vertical crystallization unit reaches a stable target material level, and starting to cool strictly according to a cooling curve after the crystal growing process is completed.

2. The multi-level automatic temperature control method for the vertical crystallizer set in the glucose crystallization process according to claim 1, which is characterized in that:

the temperature of the cooling water in each layer is set on the principle that the difference between the water temperature of the cooling coil and the material temperature is less than 5 ℃, so that a gradient with high and low is formed.

3. The multi-level automatic temperature control method for the vertical crystallizer set in the glucose crystallization process according to claim 2, which is characterized in that:

when the crystal growing process is finished and the temperature begins to be reduced, the actual temperature is judged according to the operation time, if the material temperature deviates from the target temperature, PID (proportion integration differentiation) adjustment is carried out on the material temperature of each layer by adjusting the flow of cooling water, and the accurate control on the material temperature in the crystallization process is realized.

4. The multi-level automatic temperature control method for the vertical crystallizer set in the glucose crystallization process according to claim 3, characterized in that:

after the timing is started, the temperature control values of each layer are input in 110 times at intervals of 30min, when the time point of the given temperature is in a broken line between two temperature nodes, the slope of the broken line is calculated, and the current target temperature is calculated by matching with the current time point, so that the curve type temperature control is realized, and the temperature control is more accurate.

5. The multi-level automatic temperature control method for the vertical crystallizer set in the glucose crystallization process according to claim 4, characterized in that:

the glucose crystals which are stably crystallized in the production process are output at a constant flow, at the moment, the feeding flow is associated with the feeding valve in a reaction mode, the feeding flow is input, the PID regulation is adopted to realize that the valve is properly opened when the feeding flow is small, and the valve is properly closed when the feeding flow is large, so that the aim of feeding at the constant flow and stabilizing the crystallization state is fulfilled.

Technical Field

The invention relates to the technical field of glucose crystallization production, in particular to a multi-level automatic temperature control method for a neutral crystallization unit in a glucose crystallization process.

Background

The vertical crystallizing machine set is a glucose continuous crystallizing device integrating mechanical, control, hydraulic and cooling crystallization technologies as an independent unit. At present, intelligent association is not realized between a material inlet and outlet pipe of a crystallizer set and materials in an upstream working section and a downstream working section, and the material inlet and outlet are still manually operated in a manual judgment mode. In the process of cooling and crystallizing the glucose, the automation degree of temperature control is not high, and the circulating water temperature needs to be set manually according to production experience. The high-quality finished product to be produced in the using stage of the crystallizer unit usually needs longer debugging time, and the conditions of unsatisfactory crystallization effect, poor quality of the produced finished product and the like caused by discontinuous feeding and discharging and the like can also occur in the normal using process.

Disclosure of Invention

The invention aims to provide a multi-level automatic temperature control method for a vertical crystallizer set in a glucose crystallization process, which enables the vertical crystallizer set to complete initialization more efficiently and enables the vertical crystallizer set to have more stable output.

The technical scheme adopted by the invention is as follows:

the multi-level automatic temperature control method of the vertical crystallizer set in the glucose crystallization process is characterized in that:

and starting timing after the primary feeding of the vertical crystallization unit reaches a stable target material level, and starting to cool strictly according to a cooling curve after the crystal growing process is completed.

The temperature of the cooling water in each layer is set on the principle that the difference between the water temperature of the cooling coil and the material temperature is less than 5 ℃, so that a gradient with high and low is formed.

When the crystal growing process is finished and the temperature begins to be reduced, the actual temperature is judged according to the operation time, if the material temperature deviates from the target temperature, PID (proportion integration differentiation) adjustment is carried out on the material temperature of each layer by adjusting the flow of cooling water, and the accurate control on the material temperature in the crystallization process is realized.

After the timing is started, the temperature control values of each layer are input in 110 times at intervals of 30min, when the time point of the given temperature is in a broken line between two temperature nodes, the slope of the broken line is calculated, and the current target temperature is calculated by matching with the current time point, so that the curve type temperature control is realized, and the temperature control is more accurate.

The glucose crystals which are stably crystallized in the production process are output at a constant flow, at the moment, the feeding flow is associated with the feeding valve in a reaction mode, the feeding flow is input, the PID regulation is adopted to realize that the valve is properly opened when the feeding flow is small, and the valve is properly closed when the feeding flow is large, so that the aim of feeding at the constant flow and stabilizing the crystallization state is fulfilled.

The invention has the following advantages:

the method of the invention conforms to the multi-level automatic temperature control of the temperature control curve of the temperature reduction and crystallization of the glucose. Namely, after the primary feeding of the crystallization unit reaches a stable target material level, the system starts timing, and starts automatic cooling after the crystal growing process is completed, so that the stability and continuity of cooling of each layer are realized.

2. The invention takes the crystallization process as the core and realizes automatic feeding and discharging and automatic seed crystal circulation control. Namely, the crystallization unit judges the state of the crystallization unit when the feed valve is opened, and the crystallization unit is in different states in different interlocking control modes.

Drawings

FIG. 1 is a temperature-lowering line diagram of a cooling crystallization process of glucose.

FIG. 2 is a schematic view of the cooling state at 450 min.

Fig. 3 is a schematic view of charge and discharge control in an operating state.

Detailed Description

The present invention will be described in detail with reference to specific embodiments.

The invention relates to a multi-level automatic temperature control method for a neutral crystallizer set in a glucose crystallization process, which is based on the existing vertical crystallizer set for automatic temperature control. The vertical crystallization unit comprises the following components: the cooling water flows through the cooling coil groups in a counter-flow direction, i.e. from bottom to top. To ensure accurate control of the cooling water temperature, five groups (11 layers) of cooling water were passed in. The 11-layer cooling coil group is like 11 single crystallizers connected in sequence, and the vertical crystallizer is divided into 12 crystallization zones with different cooling conditions. The material passes through each crystallization interval with the five temperature gradients decreasing from top to bottom, is crystallized gradually and moves to the bottom by the gravity of the material, so that the feeding, the crystallization, the cooling and the discharging can be carried out continuously.

The method comprises the following steps: by designing a completely new automatic control system program of the crystallizer, the vertical crystallizer set is enabled to reach a stable target material level in the initial feeding process, and after crystal growing is completed, timing is started to strictly cool according to a cooling curve. The program carries out PID calculation on the proportional relation between the valve opening and the cooling water temperature, and then reads the temperature value corresponding to each time point in the program broken line table, thereby realizing the direct setting of the target temperature of each layer of cooling water at each time point, automatically setting the temperature on the principle that the difference between the water temperature of the cooling coil and the material temperature is less than 5 ℃, and forming a gradient with high and low temperature.

When the crystallization process is accomplished and the feeding cooling begins, control system utilizes the temperature measuring instrument to gather each level material temperature in the crystallizer to procedure broken line table data is the target temperature, and the two is in order to judge the material state to the automatic contrast, if the material temperature deviates from the target temperature, control system can adjust each layer cooling water temperature through PID automatically regulated cooling water flow size, realizes the accurate control to crystallization process material temperature.

After the timing is started, the temperature control values of each layer are set at intervals of 30min in 110 times. The program broken line table function is to linearize the curve section by using a broken line approximation method so as to achieve the linearization processing of a nonlinear signal, namely when a certain time node needs to be provided with a given temperature value at an oblique line stage in the broken line table, a broken line table function block linearly calculates the temperature value of a front node and a rear node and the time difference, and the time node is operated inside the program at the position of the oblique line stage to obtain the target temperature value of the time node, so that the curve type temperature control is realized, and the temperature control is more accurate.

The system judges whether the discharging frequency converter is started or not, the discharging frequency converter is not started, the default is empty tank feeding, and an empty tank feeding program is executed; when the discharging frequency converter is started, the discharging frequency converter defaults to feeding in the production process and executes a feeding program in the production process.

The object level is associated with the feeding valve in a reaction mode in an empty tank state, the object level is input, the valve opening is increased and the large-flow rapid feeding is realized through PID regulation when the actual object level deviates and the object level is too large, the valve opening is gradually reduced when the actual object level approaches the object level, the feeding speed is stabilized, and the valve is closed to keep the liquid level when the object level reaches the object liquid level.

The glucose crystals which are stably crystallized in the production state are output at a constant flow, at the moment, the feeding flow is associated with the feeding valve in a reaction mode, the feeding flow is input, the PID regulation is used for realizing that the valve is properly opened when the feeding flow is small, and the valve is properly closed when the feeding flow is large, so that the aim of feeding the glucose crystals at the constant flow and stabilizing the crystallization state is fulfilled.

In the normal and stable crystallization production process, the seed crystals can flow back at 15-30% of the feeding flow, so that the whole material is uniformly crystallized, and the product quality is controlled while the yield is ensured.

The method has the following characteristics:

1. and the multi-level automatic temperature control is in accordance with the temperature control curve of glucose cooling crystallization. Namely, after the primary feeding of the crystallization unit reaches a stable target material level, the system starts timing, and starts automatic cooling after the crystal growing process is completed, so that the stability and continuity of cooling of each layer are realized.

2. Automatic feeding and discharging and automatic seed crystal circulation control taking the crystallization process as a core. Whether the crystallizer set is in empty can or production state is judged through reading whether ejection of compact converter operates when opening the feed valve promptly, and feeding volume and the chain automatic control of level during empty can state, feeding volume and the chain automatic control of ejection of compact volume during production state realize the reliable and stable of business turn over material process, improve product output efficiency.

The invention is not limited to the examples, and any equivalent changes to the technical solution of the invention by a person skilled in the art after reading the description of the invention are covered by the claims of the invention.