CN205474036U - Hysteresis quality pH controlling means - Google Patents

Abstract

The utility model discloses a hysteresis pH control device. The device comprises a reaction kettle, a liquid level gauge is arranged in the reaction kettle, and a reaction liquid input pipeline and an acid liquid addition pipeline are arranged on the top of the reaction kettle. The liquid high level tank is connected, the bottom of the reaction kettle is provided with a solution output pipe, the acid liquid addition pipe is provided with an acid liquid flow regulating valve, and the end of the solution output pipe is provided with a pH meter, pH meter, acid liquid flow regulating valve, liquid level gauge and The PLC is connected. The utility model solves the problem of pH control hysteresis caused by the fluctuation of the pipeline flow, insufficient mixing of local solutions in the reactor and the dynamic system in the production process of the copper removal agent, and can realize the pH control according to the liquid level in the reactor. Change and accurately control the flow rate of acid solution addition to achieve the purpose of accurately controlling the pH value of the reaction solution.

Description

A hysteresis pH control device

technical field

The utility model belongs to the technical field of nickel electrolysis production, in particular to a hysteresis pH control device.

Background technique

In the production process of nickel electrolysis, the nickel electrolyte needs copper removal treatment, and in the process of copper removal reaction, because the pH of the system plays a decisive role in the effect of the reaction, the pH value of the system is required to be maintained at a constant level. Therefore, it is necessary to accurately control the pH of the nickel electrolyte before the copper removal reaction. The pH value of the nickel electrolyte is relatively high before entering the copper removal reaction process, and sulfuric acid is generally used to adjust the pH. In the actual production process, on the one hand, affected by the previous filtration process, the nickel electrolyte flow rate of the pH adjustment reactor before entering the copper removal reaction process is not a stable value, and the liquid output is a constant value. The change of the system flow rate makes the adjustment of pH There is hysteresis, which increases the difficulty of pH control; on the other hand, the production of the pH adjustment reactor is a continuous process, except that the pH adjustment reactor has liquid outlet while entering the liquid, and the volume of the pH adjustment reactor is relatively large. The hysteresis of the reaction system is relatively large, which further increases the difficulty of pH control. Based on the above reasons, it is difficult to control the pH of the copper removal reaction solution at the required constant value. Since the flow rate of the nickel electrolyte entering the pH adjustment reactor is gradually decreasing, the pipeline used to transport the nickel electrolyte is not full of pipes, and the flow meter has a large measurement error when the pipe is not full, which makes it difficult to pass the calculation. The amount of sulfuric acid added is determined by the flow rate of the nickel electrolyte. The current operation method directly connects the pH meter with the sulfuric acid adjustment control valve, adjusts the opening of the sulfuric acid addition valve through the pH setting value, and then controls the amount of sulfuric acid addition, but this method is difficult to solve the problem of pH adjustment control hysteresis, except The pH value of the copper reaction solution still cannot be accurately controlled.

Utility model content

The purpose of the utility model is to solve the technical problems in the prior art, and provide a hysteretic pH control device that can accurately control the flow rate of acid liquid addition and accurately control the pH value of the reaction solution according to the change of the liquid level in the reactor.

In order to achieve the above object, the utility model adopts the following technical solutions: a hysteresis pH control device, including a reactor, the reactor is provided with a liquid level gauge, and the top of the reactor is provided with a reaction liquid input pipe and an acid Liquid addition pipe, the acid liquid addition pipe is connected with the acid liquid head tank, the bottom of the reaction kettle is provided with a solution output pipe, the acid liquid addition pipe is provided with an acid flow regulating valve, and the end of the solution output pipe A pH meter is provided, and the pH meter, acid liquid flow regulating valve and liquid level meter are connected with PLC.

Further, the reaction liquid input pipeline is provided with a reaction liquid input cut-off valve.

Further, the solution output pipeline is provided with a solution output cut-off valve.

Further, the liquid level gauge is a radar level gauge.

Compared with the prior art, the utility model has the following beneficial effects: the utility model adjusts the addition amount of the acid solution according to the change of the solution level in the reaction kettle, which can overcome the hysteresis effect of pH adjustment, and the acid solution addition amount passes through the acid flow regulating valve Control, the valve opening of the acid liquid flow regulating valve is related to the change of the liquid level, and the corresponding relationship of the ratio is established. The pH meter presets the pH value to be controlled. The output volume is kept constant, and the PLC adjusts the opening of the acid flow regulating valve according to the set value of the pH meter until the measured pH value is consistent with the set value, and the opening of the acid flow regulating valve remains constant. is a certain value MV ₀ , switch to the normal production process at this time. During normal production, due to the influence of the previous filtration process, the flow rate of the reaction liquid entering the reactor will gradually decrease, which will cause changes in the liquid level in the reactor. In the formula, the change value of the liquid level is set as △L. When the amount of solution entering the reactor is greater than the amount of liquid outlet, △L is a positive value. When the amount of solution entering the reactor is equal to the amount of liquid outlet, △L is zero. When the amount of solution entering the reaction kettle is less than the amount of liquid output, △L is a negative value, and the PLC finds out the relationship between the valve opening of the acid flow regulating valve and △L through adjustment, and then performs a corresponding adjustment on the basis of the original valve opening MV ₀ Increase, remain unchanged or decrease, and finally ensure that the pH value is stably controlled at the set value. The utility model solves the problem of pH control hysteresis caused by the fluctuation of pipeline flow, insufficient mixing of local solutions in the reaction kettle and the dynamic system in the production process of the copper removal agent, and achieves the purpose of accurately controlling the pH value of the reaction solution .

Description of drawings

Fig. 1 is the structural representation of the utility model.

The meanings of the reference signs of the utility model are as follows: 1. Acid liquid high level tank; 2. Acid liquid flow regulating valve; 3. Reaction liquid input shut-off valve; 4. Reactor; 5. Liquid level gauge; 6. PLC; 7. Solution Output cut-off valve; 8. pH meter; 9. Reaction solution input pipeline; 10. Acid solution addition pipeline; 11. Solution output pipeline.

detailed description

Below in conjunction with accompanying drawing and specific embodiment, the utility model is further described.

As shown in Figure 1, a hysteresis pH control device includes a reactor 4, a liquid level gauge 5 is arranged in the reactor 4, and the liquid level gauge 5 is a radar liquid level gauge, which is used to detect the liquid level in the reactor 4 , the top of the reaction kettle 4 is provided with a reaction solution input pipeline 9 and an acid solution addition pipeline 10, and the reaction solution input pipeline 9 is provided with a reaction solution input shut-off valve 3, which is used to close the reaction solution input pipeline 9 during maintenance, and the acid solution addition pipeline 10 is connected with the acid liquid head tank 1 storing acid liquid, the bottom of the reaction kettle 4 is provided with a solution output pipeline 11, and the solution output pipeline 11 is provided with a solution output shut-off valve 7, which is used to close the solution output pipeline 11 during maintenance, and the solution output The end of the pipeline 11 is provided with a pH meter 8, which is used to detect the pH of the solution in the reaction kettle 4, and the acid liquid adding pipeline 10 is provided with an acid liquid flow regulating valve 2, an acid liquid flow regulating valve 2, a pH meter 8, a liquid level gauge 5 is connected with PLC 6 .

When restarting after initial production or overhaul, the concentration of the acid solution, the concentration and flow rate of the reaction solution, the flow rate of the solution output pipeline, and the pH value of the target solution are set in advance in PLC6; Enter the reaction kettle 4 through the reaction solution input pipeline 9 and the acid solution addition pipeline 10, the reaction solution and the acid solution flow out through the solution output pipeline 11 after reacting in the reaction kettle 4, and the pH meter 8 feeds back the detection results to the PLC 6 in real time ;PLC 6. Adjust the valve opening of the acid flow regulating valve 2 according to the target value set by the pH meter 8 until the measured value fed back by the pH meter 8 is equal to the set target value. At this time, the acid flow regulating valve 2. The initial opening is maintained at a certain value, and the normal production process is switched to; during normal production, the liquid level gauge 5 feeds back the liquid level information in the reactor 4 to the PLC 6, and the PLC 6 calculates the result of the liquid level change. When entering When the amount of solution in the reaction kettle 4 is greater than the amount of liquid output, the liquid level change value △L is a positive value. When the amount of solution entering the reaction kettle 4 is equal to the amount of liquid output, △L is zero. When entering the reaction kettle 4 When the solution volume is less than the output volume, △L is a negative value. PLC 6 finds out the relationship between the valve opening of the acid flow regulating valve 2 and the liquid level change value △L by adjusting the PLC 6. 6 Fitting to get the control formula

MV= MV ₀ ＋K·△L·100%

MV——acid flow regulating valve opening (%);

MV ₀ ——Initial opening of acid flow regulating valve

△L——The height change of the reactor liquid level per unit time (m);

k——relationship coefficient.

Calculate the valve opening of the acid flow regulating valve 2 according to the above fitting formula, and the PLC 6 continuously and automatically controls the acid flow regulating valve 2 to adjust to the corresponding opening, thereby maintaining the measured value and setting of the pH meter 8 The value remains consistent, so as to achieve the purpose of accurately controlling the pH value of the solution in the reactor 4.

Claims (4)

1. hysteresis quality pH controls device, including reactor (4), it is characterized in that: in described reactor (4), be provided with liquidometer (5), the top of described reactor (4) is provided with reactant liquor input channel (9) and acid solution adds pipeline (10), described acid solution is added pipeline (10) and is connected with acid solution head tank (1), described reactor (4) bottom is provided with solution output channel (11), the end of described solution output channel (11) is provided with pH meter (8), described acid solution is added pipeline (10) and is provided with acid solution flow control valve (2), described acid solution flow control valve (2), pH meter (8), liquidometer (5) and PLC(6) it is connected.

A kind of hysteresis quality pH the most according to claim 1 controls device, it is characterised in that: described reactant liquor input channel (9) is provided with reactant liquor input stop valve (3).

A kind of hysteresis quality pH the most according to claim 1 controls device, it is characterised in that: described solution output channel (11) is provided with solution output stop valve (7).

A kind of hysteresis quality pH the most according to claim 1 controls device, it is characterised in that: described liquidometer (5) is radar level gauge.