Pre-grey reactor and method
Technical field
The present invention relates to cane sugar manufacture processing unit field, be specifically related to a kind of pre-grey reactor and method.
Background technology
China's cane sugar factory adopts sulfurous method clarification process to produce the directly white sugar of consumption more, in the middle of the production control of sulfurous method cleaning technique, stablizing of pre-grey sugarcane juice flow, pH value, technology controlling and process to subsequent production link has material impact, is directly connected to the productive capacitys such as quality product, Sugar Recovery.
Prior art is by installing and automatically control balanced sugarcane-squeezing amount hourly at squeezing machine, yet, due to sugar cane breed, shelf-time difference, the sugarcane juice amount of squeezing out still has larger fluctuation, instantaneous delivery fluctuation reaches 15-20% conventionally, some do not install sugar refinery of squeezing automatic control, and the instantaneous delivery fluctuation of its sugarcane juice is larger.
Because auxiliary material interpolation, Heating temperature, pH value, the various valve event of production line is all to control according to sugarcane juice flow, when there is fluctuation in sugarcane juice flow, can make on production line each operating unit produce a series of, chain adjustment action, when adjustment action cooperation is bad, can make fluctuation cumulative, even produce resonance effect, cause technic index to occur great departing from.Therefore, the flow control of sugarcane juice need to be that pre-ash process is done from the source of sugarcane juice.
The phosphoric acid adding proportion of pre-ash is larger on clarifying efficiency impact, the phosphoric acid of prior art adds employing quantitative manual addition means per hour, do not consider sugarcane juice flow, make the pH of pre-grey sugarcane juice that very large change occur, the control that affects the Sulphitation and Neutralization pH value of subsequent handling is stablized.At phosphoric acid, add arranging of point, the sugarcane juice of prior art has just added phosphoric acid before entering mixed juice case, cause sugarcane juice pH value in mixed juice case to be reduced to the neutral range of 6.8-7.2, because sugarcane juice temperature is now 40 ℃ of left and right, be applicable to very much the Fast-propagation of microorganism; In addition in sugarcane juice, contain a large amount of silt, bagasse, easily in mixed juice case, deposit, the microbial reproduction in casing is very serious, causes obvious sugar loss.
In addition, the mixed juice case of prior art is square box, and whipping appts is not set, hybrid reaction effect between sugarcane juice, phosphoric acid, milk of lime is bad, in addition static silt particle, the sugarcane chaff of easily making of sugarcane juice is deposited on dead angle, and microbial reproduction produces sugarcane meal, unfavorable to quality product and sugar withdrawal.
Summary of the invention
The present invention aims to provide a kind of pre-grey reactor and method, can effectively stablize sugarcane juice output flow, pH value, milk of lime, phosphoric acid addition, guarantees that follow-up sugarcane juice flow and pH value there will not be significantly sudden change, improve pre-grey reaction efficiency simultaneously.
Technical scheme of the present invention is as follows: a kind of pre-grey reactor, comprises that cylinder, juice-feeding tube, juice yield tube, whipping appts, pH control device, flow rate control device, phosphoric acid adder and frequency conversion go out juice pump;
Described frequency conversion goes out juice pump and is communicated with cylinder by juice yield tube;
Described pH control device detects juice-feeding tube exit sugarcane juice pH, and the milk of lime amount adding by control control enters cylinder sugarcane juice pH;
Described flow rate control device detects the sugarcane juice flow of juice yield tube, goes out the rotating speed of juice pump pump according to sugarcane juice flow control frequency conversion, according to sugarcane juice traffic transport, controls signal to phosphoric acid adder;
Described phosphoric acid adder adds phosphoric acid according to control signal in cylinder bottom or juice yield tube.
Described pH control device comprises pH detector, pH controller, milk of lime adder;
Described pH detector is connected with juice-feeding tube tail end, for detection of the sugarcane juice pH of this place, and by pH information transmission to pH controller;
Described pH controller transfers to milk of lime adder according to pH information by corresponding control signal;
Described milk of lime adder is connected with the front end of juice-feeding tube, completes the interpolation of milk of lime according to the control signal receiving.
Described flow rate control device comprises flow detector, liquid level detector, flow director, goes out juice frequency transformer;
Described flow detector is connected with juice yield tube, is used for detecting sugarcane juice output flow information, and transfers to flow director;
Described liquid level detector is connected with cylinder, is used for detecting the liquid level in cylinder, and by liquid level information transmission to flow director;
Described flow director is according to the flow information and the liquid level information that receive, carry out comprehensive computing after output control signal to out juice frequency transformer accordingly, output controls signal to phosphoric acid adder accordingly;
Described goes out juice frequency transformer according to the control signal of flow director, controls the rotating speed that frequency conversion goes out juice pump;
Described phosphoric acid adder, according to the control signal of flow director, adds phosphoric acid in cylinder bottom or juice yield tube.
Described whipping appts comprises mixing control module, stirs frequency transformer, variable-frequency motor, agitator;
Described mixing control module, for sending steering order to stirring frequency transformer, is controlled the output frequency that stirs frequency transformer;
Described stirring frequency transformer, according to the steering order of mixing control module, sends control signal to variable-frequency motor, controls the running speed of variable-frequency motor;
Described variable-frequency motor is connected with agitator, controls the velocity of rotation of agitator.
Described liquid level detector is fluid level transmitter; Described fluid level controller comprises PID setter;
Described fluid level transmitter detects the liquid level information in cylinder, and liquid level information is converted to analog current signal transfers to PID setter;
Described PID setter carries out A/D by the analog current signal receiving and is converted into liquid level numerical signal, and this liquid level numerical signal and default higher limit, lower value are compared to computing, then through D/A, operation result is converted into current signal transfer to going out juice frequency transformer;
Described goes out juice frequency transformer according to the current signal regulating frequency output of PID setter output, controls the rotating speed that frequency conversion goes out juice pump.
The present invention also provides a kind of pre-grey method, comprises the following steps:
A, the default pH span of control parameter of pH control device, the sugarcane juice pH of detection juice-feeding tube, calculates according to sugarcane juice pH value and preset value difference the milk of lime amount that real-time need add, and adds the milk of lime amount of this amount;
B, flow rate control device detect the sugarcane juice flow in juice yield tube by flow detector, and flow information is carried out to A/D be converted into flow number signal, transfer to flow director, compare computing with preset flow value, operation result is converted to current signal to going out juice frequency transformer by D/A, controls out juice revolution speed;
C, flow rate control device detect the liquid level information in cylinder by liquid level detector, and itself and default higher limit, lower value are compared to computing, and when liquid level surpasses higher limit, flow rate control device is controlled frequency conversion and gone out juice pump and rotate at full speed; When liquid level is during lower than lower value, flow rate control device is controlled frequency conversion and is gone out juice pump and stop operating;
D, phosphoric acid adder according to control signal to the phosphoric acid that adds respective amount in cylinder bottom or juice yield tube.
In described step a, the default pH span of control of pH control device is for being 7.5-9.5.
In described c step, it is 50-800ppm that phosphoric acid adder is controlled phosphoric acid concentration scope.
The working process of the pre-grey reactor of the present invention is as follows:
A, the sugarcane juice of processing through a upper operation flow to pre-ash process by juice-feeding tube, and described pH detector detects the sugarcane juice pH of juice-feeding tube, and by pH information transmission to pH controller; PH controller transfers to milk of lime adder according to pH information by corresponding control signal, keeps the stable of juice-feeding tube sugarcane juice pH, and milk of lime adder completes the interpolation of milk of lime according to the control signal receiving;
B, through adding the sugarcane juice of ash adjusting, by juice-feeding tube, enter in pre-grey reactor, liquid level is along with the inflow of sugarcane juice is constantly risen, sugarcane juice flows out pre-grey reactor by juice yield tube simultaneously, described flow detector detects the sugarcane juice flow in juice yield tube, and flow information is carried out to A/D be converted into flow number signal, transfer to flow director, compare computing with preset flow value, operation result is converted to current signal to going out juice frequency transformer by D/A, control out juice revolution speed, be preset with the scale parameter of phosphoric acid addition and sugarcane juice flow, according to sugarcane juice under meter, calculate the phosphoric acid amount that real-time need add, output corresponding control signal is to phosphoric acid adder, described fluid level transmitter detects the liquid level information in cylinder, and liquid level information is converted to analog current signal transfers to PID setter, described PID setter carries out A/D by the analog current signal receiving and is converted into liquid level numerical signal, and compare computing with default higher limit and lower value, as the emergency response mechanism under limiting case, when liquid level numerical signal surpasses higher limit, PID setter is controlled frequency conversion and is gone out juice pump and rotate at full speed to going out juice frequency transformer by sending corresponding control signal, when liquid level numerical signal is during lower than lower value, PID setter is controlled frequency conversion and is gone out juice pump and stop operating to going out juice frequency transformer by sending corresponding control signal, through such regulate process, realize when the flow in pre-grey reactor is controlled and guarantee that liquid level there will not be great fluctuation process, guarantee the stable of liquid level and output flow,
C, phosphoric acid adder complete the interpolation of phosphoric acid according to the control signal receiving, keep the stablizing of ratio of sugarcane juice flow and phosphoric acid addition;
D, when needs stir, start whipping appts, by mixing control module, to stirring frequency transformer, send steering order, control the output frequency that stirs frequency transformer, stir frequency transformer according to the steering order of mixing control module, to variable-frequency motor, send control signal, control the running speed of variable-frequency motor, and then the velocity of rotation of control agitator, drive the sugarcane juice rotation in pre-grey reactor.
Wherein the principle of PID setter difference computing is, according to INTELLIGENT PID REGULATOR flow setting value and flow detector actual measured value in control process, carry out difference computing, according to level imbalance E and deviation variation rate EC, carry out decision-making, PID setter is by P(ratio), I(integration), D(differential) three control the parameters sampling periods of output.The error E that sampling is obtained and error rate EC show that after Fuzzy Processing adjustment amount goes to control controlled plant.Within the sampling period, PID setter computing module is sampled to flow, and actual flow value Y is compared with set-point S, obtain the deviation E=Y-S of flow, through PID setter computing module, process digital quantity EC=E (the k)-E (k-1) that can obtain change of error.E and EC be through quantizing conversion Calculation manipulated variable, then be multiplied by quantizing factor and obtain working control amount, is used for the time of setting up a call of Control PID setter internal solid rly., thereby regulate the frequency of frequency transformer to reach control object.Meanwhile, consider interference free performance, preferably the input and output type of PID setter is all set as to 4 ~ 20mA current type, when flow number signal is during lower than limit value, its outward current is made as the current type of 4 ~ 12mA; When flow number signal is during higher than limit value, PID current regulator is made as the current type of 12 ~ 20mA; Meanwhile, fluid level transmitter detects the liquid level of cylinder, and liquid level numerical signal is carried out to above-mentioned calculating, and when liquid level numerical signal is during lower than lower value, its outward current is made as 0mA; When liquid level numerical signal is during higher than higher limit, PID current regulator is made as 20mA.
In the present invention program, according to the difference of the flow information in pre-grey reactor and limit value, control the output frequency of frequency transformer, throughput ratio limit value is high must be more, control frequency transformer frequency of delivery less, and it is just slower that frequency conversion goes out the running speed of juice pump; Throughput ratio limit value is low must be more, control frequency transformer frequency of delivery larger, and it is just faster that frequency conversion goes out the running speed of juice pump; Detailed process is as follows: when flow exceeds default limit value, control frequency conversion and go out juice pump decelerate, until flow is got back to limit value place; When flow is during lower than limit value, control frequency conversion and go out the accelerated service of juice pump, until flow is got back to limit value place; Also the liquid level information in pre-grey reactor is detected simultaneously, and be preset with higher limit and lower value, when liquid level exceeds default higher limit, control frequency conversion and go out the full-speed operation of juice pump, until liquid level is got back to limit value place; When liquid level is during lower than lower value, control frequency conversion and go out juice pump and shut down, until liquid level is got back to limit value place.Pre-grey reactor flow and liquid level are repeated to above-mentioned dynamic adjustments, the output flow of finally realizing pre-grey reactor maintains in the fluctuation range of default limit value, makes pre-grey reactor output flow stable and under limiting condition, prevent the situation of the emptying or spill-over of sugarcane juice.Because pre-grey subsequent handling Sulphitation and Neutralization is to calculate the sulfurous gas of input and milk of lime amount based on amount of liquid, if the fluctuation of the output flow of pre-ash process is too large, the automatic adjusting subject range that can exceed Sulphitation and Neutralization operation, make the sugarcane juice amount of Sulphitation and Neutralization operation occur fluctuation, stability and the controllability of Sulphitation and Neutralization operation have been affected, finally affect Sulphitation and Neutralization effect, cause the clarifying effect of sugarcane juice and sucrose quality to reduce, reduce output and the quality of sucrose.Therefore, the flow control mechanism of this pre-grey reactor is actual is to have important function and significance, controls the flow of this process well, makes subsequent handling there will not be significantly flow sudden change, can be good at guaranteeing the good operation of subsequent handling, obtain high-quality sucrose.
Pre-grey method provided by the invention utilizes above-mentioned pre-grey reactor to carry out, and at the juice feeding tube place of pre-grey reactor, adds milk of lime, and controlling sugarcane juice pH is 7.5-9.5, thereby strengthens the coacervation of colloidal suspended substance and the precipitation of pigment impurity, improves pre-grey effect; In pre-grey process, cylinder liquid level and output flow are carried out to dual control, both guaranteed the time of pre-ash reaction, prevent that again fluctuation from appearring in output flow; And adding phosphoric acid in cylinder bottom or juice yield tube, the precipitation of generation can strengthen the adsorption effect to pigment, reduces colour, simultaneously, the interpolation of phosphoric acid and the flow of juice yield tube keep certain proportion, prevent that large change from appearring in sugarcane juice pH, make sugarcane juice pH meet the requirement of subsequent handling; And before milk of lime is arranged on and enters reactor, phosphoric acid adds the outlet that point is arranged on reactor, make the sugarcane juice in reactor keep alkalescence, suppress microorganism and breed in device.。
The whipping appts of the variable-ratio in the pre-grey reactor of the present invention can make sugarcane juice in pre-grey reactor in the state of rotatablely moving, by rational liquid level is set, control suitable sugarcane juice amount, guarantee sugarcane juice speed of rotation and effect, improve reaction efficiency, utilize the impurity such as sugarcane chaff in sugarcane juice simultaneously, these impurity are along with internal tank surface is washed away in the cyclotron motion meeting of sugarcane juice, and the tank skin that constantly rubs, cannot accumulate the bacterium of tank skin, reduce bacterial reproduction in container, container is cleaned simultaneously.
In sum, the pre-grey reactor of the present invention and method, by the flow control of pre-grey reactor, flow rate fluctuation is reduced to 5%-10%, make subsequent handling there will not be significantly flow and pH value mutation, guarantee that Sulphitation and Neutralization is stable, and then guarantee sucrose yield and quality.
Accompanying drawing explanation
The structural representation of the pre-grey reactor that Fig. 1 provides for the embodiment of the present invention.
In figure, each several part title and label are as follows:
1 is cylinder, and 2 is juice-feeding tube, and 3 is juice yield tube, 4 is whipping appts, and 5 for frequency conversion goes out juice pump, and 6 is pH detector, 7 is pH controller, and 8 is milk of lime adder, and 9 is liquid level detector, 10 is flow director, 11 for going out juice frequency transformer, and 12 is flow detector, and 13 is phosphoric acid adder, 14 is milk of lime container, and 15 is phosphoric acid container.
Embodiment
Below in conjunction with drawings and Examples, illustrate the present invention.
Embodiment 1
As shown in Figure 1, the pre-grey reactor that the present embodiment provides, comprises that cylinder 1, juice-feeding tube 2, juice yield tube 3, whipping appts 4, pH control device, flow rate control device, phosphoric acid adder 13 and frequency conversion go out juice pump 5;
Described frequency conversion goes out juice pump 5 and is communicated with cylinder 1 by juice yield tube 3;
Described pH control device detects juice-feeding tube 2 exit sugarcane juice pH, and the milk of lime amount adding by control control enters cylinder 1 sugarcane juice pH;
Described flow rate control device detects liquid level information in cylinder 1 and the sugarcane juice flow of juice yield tube 3, goes out the rotating speed of juice pump 5 pumps according to described liquid level information and sugarcane juice flow control frequency conversion, according to sugarcane juice traffic transport, controls signal to phosphoric acid adder 13;
Described phosphoric acid adder 13 adds phosphoric acid according to control signal in cylinder 1 bottom or juice yield tube 2.
Described pH control device comprises pH detector 6, pH controller 7, milk of lime adder 8;
Described pH detector 6 is connected with juice-feeding tube 2 tail ends, for detection of the sugarcane juice pH of this place, and by pH information transmission to pH controller 7;
Described pH controller 7 transfers to milk of lime adder 8 according to pH information by corresponding control signal;
Described milk of lime adder 8 is connected with the front end of juice-feeding tube 2, completes the interpolation of milk of lime according to the control signal receiving.
Described flow rate control device comprises flow detector 12, liquid level detector 9, flow director 10, goes out juice frequency transformer 11;
Described flow detector 12 is connected with juice yield tube 3, is used for detecting sugarcane juice output flow information, and transfers to flow director 10;
Described liquid level detector 9 is connected with cylinder 1, is used for detecting the liquid level in cylinder 1, and by liquid level information transmission to flow director 10;
Described flow director 10 is according to the flow information and the liquid level information that receive, carry out comprehensive computing after output control signal to out juice frequency transformer 11 accordingly, output controls signal to phosphoric acid adder 13 accordingly;
Described goes out juice frequency transformer 11 according to the control signal of flow director 10, controls the rotating speed that frequency conversion goes out juice pump 5;
Described phosphoric acid adder 13, according to the control signal of flow director 10, adds phosphoric acid in cylinder 1 bottom or juice yield tube 3;
In the present embodiment, liquid level detector 9 adopts fluid level transmitter, and fluid level controller 10 comprises PID setter.
The working process of the pre-grey reactor of the present embodiment is as follows:
A, the sugarcane juice of processing through a upper operation flow to pre-ash process by juice-feeding tube, and described pH detector detects the sugarcane juice pH of juice-feeding tube, and by pH information transmission to pH controller; PH controller transfers to milk of lime adder according to pH information by corresponding control signal, keeps the stable of juice-feeding tube sugarcane juice pH, and milk of lime adder completes the interpolation of milk of lime according to the control signal receiving;
B, through adding the sugarcane juice of ash adjusting, by juice-feeding tube, enter in pre-grey reactor, liquid level is along with the inflow of sugarcane juice is constantly risen, sugarcane juice flows out pre-grey reactor by juice yield tube simultaneously, described flow detector detects the sugarcane juice flow in juice yield tube, and flow information is carried out to A/D be converted into flow number signal, transfer to flow director, compare computing with preset flow value, operation result is converted to current signal to going out juice frequency transformer by D/A, control out juice revolution speed, be preset with the scale parameter of phosphoric acid addition and sugarcane juice flow, according to sugarcane juice under meter, calculate the phosphoric acid amount that real-time need add, output corresponding control signal is to phosphoric acid adder, described fluid level transmitter detects the liquid level information in cylinder, and liquid level information is converted to analog current signal transfers to PID setter, described PID setter carries out A/D by the analog current signal receiving and is converted into liquid level numerical signal, and compare computing with default higher limit and lower value, as the emergency response mechanism under limiting case, when liquid level numerical signal surpasses higher limit, PID setter is controlled frequency conversion and is gone out juice pump and rotate at full speed to going out juice frequency transformer by sending corresponding control signal, when liquid level numerical signal is during lower than lower value, PID setter is controlled frequency conversion and is gone out juice pump and stop operating to going out juice frequency transformer by sending corresponding control signal, through such regulate process, realize when the flow in pre-grey reactor is controlled and guarantee that liquid level there will not be great fluctuation process, guarantee the stable of liquid level and output flow,
C, phosphoric acid adder complete the interpolation of phosphoric acid according to the control signal receiving, keep the stablizing of ratio of sugarcane juice flow and phosphoric acid addition;
D, when needs stir, start whipping appts, by mixing control module, to stirring frequency transformer, send steering order, control the output frequency that stirs frequency transformer, stir frequency transformer according to the steering order of mixing control module, to variable-frequency motor, send control signal, control the running speed of variable-frequency motor, and then the velocity of rotation of control agitator, drive the sugarcane juice rotation in pre-grey reactor.
Embodiment 2
The pre-grey method of the present embodiment comprises the following steps:
During squeezing process before pre-ash process, the sugarcane juice pH that controls squeezing process output is 6.8;
A, the default pH span of control parameter of pH control device, the sugarcane juice pH of detection juice-feeding tube, calculates according to sugarcane juice pH value and preset value difference the milk of lime amount that real-time need add, and controlling juice-feeding tube sugarcane juice pH is 7.5;
B, flow rate control device detect the sugarcane juice flow in juice yield tube by flow detector, and flow information is carried out to A/D be converted into flow number signal, transfer to flow director, compare computing with preset flow value, operation result is converted to current signal to going out juice frequency transformer by D/A, controls out juice revolution speed;
C, flow rate control device detect the liquid level information in cylinder by liquid level detector, and itself and default higher limit, lower value are compared to computing, and when liquid level surpasses higher limit, flow rate control device is controlled frequency conversion and gone out juice pump and rotate at full speed; When liquid level is during lower than lower value, flow rate control device is controlled frequency conversion and is gone out juice pump and stop operating;
It is 50ppm that d, phosphoric acid adder control juice yield tube phosphoric acid concentration according to control signal to the phosphoric acid that adds respective amount in cylinder bottom or juice yield tube.
Embodiment 3
The pre-grey method of the present embodiment comprises the following steps:
During squeezing process before pre-ash process, the sugarcane juice pH that controls squeezing process output is 8.0;
A, the default pH span of control parameter of pH control device, the sugarcane juice pH of detection juice-feeding tube, calculates according to sugarcane juice pH value and preset value difference the milk of lime amount that real-time need add, and controlling juice-feeding tube sugarcane juice pH is 9.5;
B, flow rate control device detect the sugarcane juice flow in juice yield tube by flow detector, and flow information is carried out to A/D be converted into flow number signal, transfer to flow director, compare computing with preset flow value, operation result is converted to current signal to going out juice frequency transformer by D/A, controls out juice revolution speed;
C, flow rate control device detect the liquid level information in cylinder by liquid level detector, and itself and default higher limit, lower value are compared to computing, and when liquid level surpasses higher limit, flow rate control device is controlled frequency conversion and gone out juice pump and rotate at full speed; When liquid level is during lower than lower value, flow rate control device is controlled frequency conversion and is gone out juice pump and stop operating;
D, phosphoric acid adder are according to control signal to the phosphoric acid that adds respective amount in cylinder bottom or juice yield tube, and controlling juice yield tube phosphoric acid concentration is 800ppm.
Embodiment 4
The pre-grey method of the present embodiment comprises the following steps:
During squeezing process before pre-ash process, the sugarcane juice pH that controls squeezing process output is 7.5;
A, the default pH span of control parameter of pH control device, the sugarcane juice pH of detection juice-feeding tube, calculates according to sugarcane juice pH value and preset value difference the milk of lime amount that real-time need add, and controlling juice-feeding tube sugarcane juice pH is 8.5;
B, flow rate control device detect the sugarcane juice flow in juice yield tube by flow detector, and flow information is carried out to A/D be converted into flow number signal, transfer to flow director, compare computing with preset flow value, operation result is converted to current signal to going out juice frequency transformer by D/A, controls out juice revolution speed;
C, flow rate control device detect the liquid level information in cylinder by liquid level detector, and itself and default higher limit, lower value are compared to computing, and when liquid level surpasses higher limit, flow rate control device is controlled frequency conversion and gone out juice pump and rotate at full speed; When liquid level is during lower than lower value, flow rate control device is controlled frequency conversion and is gone out juice pump and stop operating;
D, phosphoric acid adder are according to control signal to the phosphoric acid that adds respective amount in cylinder bottom or juice yield tube, and controlling juice yield tube phosphoric acid concentration is 400ppm.