A speed control method and circuit for stirring motor of pharmaceutical crystallization tank

Abstract

A method and circuit for controlling the speed regulation of a stirring motor of a pharmaceutical crystallization tank, using a frequency converter to control the operation of the stirring motor, and setting three frequency constants in the internal module of the frequency converter and the program stored therein, so that different frequencies correspond to high, medium and low speeds, respectively, and using the output of the enable control signal terminal of the frequency converter corresponding to the three frequencies to control the speed of the stirring motor. The control circuit includes a frequency converter, and the stirring motor is a variable frequency motor. The frequency converter controls the operation of the stirring motor, and the frequency converter is provided with several preset frequency values. The frequency converter controls the operation of the stirring motor corresponding to different speeds according to the selected frequency values, and the frequency converter has an enable control signal terminal corresponding to the frequency number. When the enable control signal terminal is selected, the stirring motor is controlled to operate at the corresponding speed. The on-site manual and automatic speed regulation control of the crystallization tank is simplified, the on-site control operation is convenient, and the investment cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of medicine production, in particular to a speed regulation control method and a circuit for a stirring motor of a medicine crystallization tank. Background Art

[0002] At present, crystallization tanks used in the pharmaceutical industry are mostly used in the production process of raw materials. In the production process, it is usually necessary to control the stirring speed according to the state of the crystallized material. At present, frequency conversion speed regulation is usually used for speed control.

[0003] The existing frequency conversion speed control means generally adopts a manual adjustment device to achieve continuous adjustment of the frequency of the frequency converter, or a complex PLC control cabinet is set for each crystallization tank to achieve automatic adjustment of the stirring speed.

[0004] However, the first control method mentioned above has high requirements for on-site operators, and manual frequency adjustment is very likely to cause human operating errors; in addition, since the frequency modulation analog signal is easily interfered with and generates signal attenuation during transmission, the adjustment frequency will be biased. And the second method, when using the automatic control method, is generally the PLC system that automatically adjusts the motor frequency according to the data fed back by the tank monitoring instrument, but due to the large number of characteristic parameters of the material in the tank, the control logic is relatively complex, making the investment cost relatively high. Therefore, the inventors have developed the method and control circuit of the present invention in combination with the production experience accumulated in the project, the operating rules of the crystallization tank stirring motor and the process requirements, and simplified the frequency conversion speed regulation control logic of the stirring system, which better avoids the above problems, and also realizes manual and automatic frequency conversion control methods. Under the premise of meeting the process production requirements, it is convenient to operate and control the cost investment, and the cost performance is relatively high. Summary of the invention

[0005] In order to solve the above problems, the main purpose of the present invention is to provide a speed control method and circuit for a stirring motor of a pharmaceutical crystallization tank, so as to facilitate operation and control cost investment while meeting process production requirements, thereby achieving a relatively high cost-effectiveness.

[0006] To achieve the above object, the present invention provides a speed control circuit for a stirring motor of a pharmaceutical crystallization tank, the control circuit includes a frequency converter, the stirring motor is a variable frequency motor, the frequency converter controls the stirring motor to operate, the frequency converter is provided with several preset frequency values, the frequency converter controls the stirring motor to operate at different speeds according to the selected frequency values, and the frequency converter has an enable control signal terminal corresponding to the frequency number, when the enable control signal terminal is selected, the stirring motor is controlled to operate at the corresponding speed. The motor stirring speed control is selected within the range of several or no more than three speed setting values, and the material stirring control of conventional crystallization tanks in the pharmaceutical industry does not require too high precision at the lowest cost.

[0007] Preferably, the frequency converter has a power input terminal for receiving three-phase AC power, a drive output terminal connected to the stirring motor, and a main circuit composed of the stirring motor (M), the frequency converter (UF) and the three-phase AC power supply. In the main circuit, the AC power supply controls the operation of the stirring motor M (variable frequency motor) through the frequency converter (UF), and the frequency converter also has an interlocking start-stop port, and the frequency converter controls the start and stop of the stirring motor according to the connection status of the interlocking start-stop port.

[0008] Preferably, the frequency converter has a digital speed output terminal for connecting to a digital tachometer, a control operation indication switch (K1) for controlling an operation indicator light (PGG), and a fault indication switch (K2) for controlling a fault indicator light (PGY).

[0009] Preferably, the control circuit further comprises an auxiliary control module, which mainly comprises an interlocking start-stop switch circuit and a speed selection module. The interlocking start-stop switch circuit and the speed selection module can be controlled by a three-speed fixed value manual / automatic adjustment method.

[0010] Preferably, the interlock start-stop switch circuit and the speed selection module are composed of relays, and the normally open contacts of the relays respectively form a switching circuit with the interlock start-stop port or the enable control signal terminal, one end of the relay coil is connected to the neutral line, and the other end is connected to the interlock start-stop switch circuit or the speed selection module.

[0011] Preferably, the frequency number is 3, corresponding to the three speeds of high, medium and low respectively. The auxiliary control module also includes a time controller (KT), which has four output contacts for outputting control signals. The control signals are respectively a start-stop control output signal and three speed regulation output signals. The start-stop and speed regulation control output times of the time controller can be programmed and set according to the production process flow, the start-stop control output signal.

[0012] Preferably, the control signals respectively control the power supply of the relay coils.

[0013] Preferably, the time controller has a reset pin, which is connected to a normally open reset switch (SBFT), and the auxiliary control module further includes a manual / automatic selection switch (SA1).

[0014] Preferably, the manual circuit of the interlocked start-stop switch circuit includes a normally closed button as a manual stop switch SBF and a normally open button switch as a start button SBS connected in series, the other end of the start button SBS is connected to the start-stop relay KA coil, and the normally open end of the start-stop relay KA is connected in parallel with the start button SBS and the start-stop control terminal (KT1), so that the start-stop relay KA and the start button SBS form a self-locking starting circuit.

[0015] Preferably, a phase line in the AC power supply is connected to the power supply terminal L of the time controller through a fuse FU4, and the N terminal of the time controller is connected to the neutral line of the power supply to form a power supply circuit.

[0016] Since the material stirring control of conventional crystallization tanks in the pharmaceutical industry does not require too high precision, generally speaking, the motor stirring speed control range usually does not exceed three speed setting values. Therefore, the present invention also provides a speed control method for a pharmaceutical crystallization tank stirring motor, using a frequency converter (UF) to control the operation of the stirring motor, and setting three frequency constants in the internal module of the frequency converter (UF) and the program stored in it, so that different frequencies correspond to high, medium and low speeds respectively, and the speed of the stirring motor is controlled by using the enable control signal terminal output corresponding to the three frequencies of the frequency converter.

[0017] Preferably, manual control can be adopted, and a motor manual start and stop button (SBS, SBF) and a high, medium and low speed conversion switch SA are set in the local control box of the crystallization tank to control the start and stop of the motor. At the same time, according to the crystallization process and material status, the action can be selected through the relay (KA1, KA2, KA3) to give the inverter a high, medium and low trigger signal, so that the inverter UF can enter three different frequency states, thereby controlling the stirring motor M to enter the third speed.

[0018] Preferably, in order to improve productivity, according to the crystallization time period in the production process, a time controller KT can be used to output contact control signals at the control endpoints (KT0-KT3) in different time periods, and the contact control signals are connected to the start-stop control and inverter speed control loops, corresponding to the start-stop and high, medium and low speed control respectively. The start-stop and speed control output times of the time controller are programmed and set according to the production process.

[0019] Furthermore, the time controller restores the initial timing state of the time controller through a reset button SBFT.

[0020] Furthermore, a three-speed fixed-value manual / automatic adjustment method can be adopted.

[0021] The beneficial effect of the present invention is that, with the help of the above technical solution, the on-site manual and automatic speed control of the crystallization tank is simplified, the on-site control operation is convenient, and the investment cost is reduced. Manual and automatic frequency conversion control modes are realized, which are convenient for operation and control cost investment under the premise of meeting the process production requirements, and the cost performance is relatively high. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a schematic diagram of a speed control circuit for a stirring motor of a medicine crystallization tank. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0024] The inventor combined engineering experience and invented and designed a crystallization tank motor speed control circuit that is easy to operate based on the actual operation requirements of the crystallization tank in the general pharmaceutical industry.

[0025] The following examples are only used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0026] like Figure 1 The figure shows a schematic diagram of a speed control circuit of a stirring motor of a medicine crystallization tank of the present invention.

[0027] The circuit is mainly composed of the following parts: main circuit, interlocking start-stop switch, operation, fault and power indication, fuse, time controller (interlocking output), controller power circuit, reset button, manual start-stop control circuit, automatic start-stop control circuit, manual start-stop, automatic start-stop selection switch, manual three-speed speed control, automatic three-speed speed control, etc. It can also include a local tachometer and a three-speed speed input device.

[0028] The invention discloses a medicine crystallization tank stirring motor speed control circuit, which is mainly composed of a main circuit consisting of a frequency converter (UF), an AC power supply and a stirring motor M, and an auxiliary control module.

[0029] Wherein, in the main circuit, the AC power source controls the operation of the stirring motor M (variable frequency motor) through the frequency converter (UF), and the frequency converter (UF) may be provided with a program or logic circuit inside, which can store three preset frequency constants, and can make different frequencies correspond to high, medium and low speeds respectively to control the operation of the stirring motor M, and is correspondingly controlled by the three corresponding enable control signal terminals (D11, D12, D13) of the frequency converter. The preset frequency constant can be input by a three-speed speed input device. It is known to those skilled in the art that the functions of storing preset values ​​and controlling the operation of the stirring motor M according to the frequency of the preset values ​​can be implemented using any existing technology including software control and hardware logic control.

[0030] The frequency converter UF is provided with an interlock start-stop port (33, 34) and three enable control signal terminals (D11, D12, D13) corresponding to the preset speed, and the interlock start-stop port (33, 34) is connected to an interlock start-stop switch KA. The frequency converter UF can also be connected with a digital tachometer A0, a running switch K1, and a fault switch K2. One phase line in the AC power supply supplies power to the auxiliary circuit through a fuse FU4. Specific embodiment 1

[0032] In this specific embodiment, a manual control method is adopted, that is, the auxiliary control module only needs to be controlled by a manual switch, and a start-stop switch and three interlocking speed selection switches can be set in the local control box.

[0033] The start-stop switch is connected to the interlock start-stop port (33, 34) to control the start and stop of the stirring motor M, and the three interlock speed selection switches are respectively connected between the enable control signal terminal (D11, D12, D13) and the common terminal COM to respectively set the three speeds of high, medium and low.

[0034] The start-stop switch can be a self-locking switch or a self-locking switch composed of a relay KA and two manual start-stop buttons.

[0035] The frequency converter UF may further include a control operation indication switch K1 and a fault indication switch K2, wherein when K1 is closed, the control operation indication light PGG is on, and when the fault indication switch K2 is closed, the fault indication light PGY is on. Specific embodiment 2

[0037] In this specific embodiment, the auxiliary control circuit mainly includes a time controller KT, a manual / automatic selection switch SA1, a manual control unit and an automatic control unit.

[0038] A phase line in the AC power supply is connected to the power supply terminal L of the time controller through a fuse FU4, and the N terminal of the time controller is connected to the neutral line of the power supply to form a power supply circuit.

[0039] The time controller KT has four control terminals (KT0-KT3) to output contact control signals (the contact signals are start-stop signals and speed control output signals respectively), and is provided with a reset pin. The frequency converter (UF) can input a preset timing sequence, and can output contact control signals from the four control terminals (KT0-KT3) according to the preset timing sequence. The four control terminals are respectively connected to the coils of four relays (KA0-4) to control the power supply of the coils. The normally open contacts of the relays (KA0-4) are respectively used to control the interlock start-stop port and the on-off of the three control signal terminals (D11, D12, D13), and respectively control the start-stop and high, medium and low speed selection of the stirring motor M. The reset pin of the time controller is connected to a normally open reset switch SBFT. The frequency converter (UF) and the four relays (KA0-4) can form an automatic control unit.

[0040] The auxiliary circuit can also be provided with a local tachometer, a three-speed speed input device, a manual / automatic selection switch SA1, wherein the selection switch SA1 can be provided with three gears, namely automatic, maintenance, and manual, D11, D12, D13, and COM time controller interlocking output (KT0, KT1, KT2, KT3).

[0041] The manual control unit is composed of a normally closed manual stop switch SBF and a normally open start switch SBS. When the selector switch SA1 is in the manual gear, the control power supply is connected to the manual stop switch through the switch. The manual stop switch SBF is a normally closed button switch. The other end of the manual stop switch is connected to the start button SBS. The start button SBS is a normally open button. The other end of the start button SBS is connected to the start-stop relay KA coil, and the normally open end of the start-stop relay KA is connected in parallel with the start button SBS and the start-stop control terminal (KT1), so that the start-stop relay KA and the start button SBS form a self-locking starting circuit.

[0042] Now, combined with the above circuit, its control method and principle are explained as follows:

[0043] Since the material stirring control of conventional crystallization tanks in the pharmaceutical industry does not require too high precision, generally speaking, the motor stirring speed control range usually does not exceed three speed setting values, so a three-speed fixed value manual / automatic adjustment method can be used.

[0044] One phase line of the three-phase AC power supply can be used to supply power to the auxiliary control circuit through fuse FU4.

[0045] 1. Set three frequency constants through the internal module of the inverter UF and its stored program, so that different frequencies correspond to high, medium and low speeds respectively, and correspond to the three corresponding enable control signal terminals (D11, D12, D13) of the inverter.

[0046] 2. Manual control:

[0047] Set the manual / automatic selection switch SA1 to manual, and set the motor manual start and stop buttons (SBS, SBF) and the high, medium and low speed conversion switch SA in the local control box of the crystallizer to control the start and stop of the motor. At the same time, according to the crystallization process and material status, the gear selection can be manually switched through the relay (KA1, KA2, KA3) to select the action to give the inverter high, medium and low trigger signals, so that the inverter UF can enter three different frequency states, thereby controlling the stirring motor M to enter three speed gears.

[0048] 3. Automatic control:

[0049] (1) When the manual / automatic selection switch SA1 is selected to automatic, according to the crystallization time period in the production process, the time controller KT outputs the contact control signal (contact signal) at the control end point (KT0-KT3) in different time periods. The contact signal terminal is connected to the inverter speed control circuit, corresponding to the start-stop and high, medium and low speed control respectively.

[0050] (2) The start and stop and speed control output time of the time controller can be programmed according to the production process.

[0051] (3) The time controller can be restored to its initial timing state by pressing the reset button SBFT.

[0052] (4) The time controller has a memory function and can continue to perform process control after a short power outage.

[0053] Taking the intermittent stirring crystallization process as an example, assuming that the crystallization start time is 0, according to the product crystallization curve, high-speed stirring is required at 2 o'clock, lasting for 30 minutes, medium-speed stirring is required at 4 o'clock, lasting for 40 minutes, and low-speed stirring is required at 6 o'clock, lasting for 60 minutes. The time control program logic is as follows:

[0054] 00:00SBFT resets, time controller KT starts timing;

[0055] 02:00 The control terminal KT0 contact closes the output and uses the interlock relay KA to close the interlock start-stop switch of the frequency converter UF, starting the stirring motor M;

[0056] At this time, the control terminal KT1 contact is closed and output, and the interlock relay KA1 is energized to output a high-speed signal to the enable control signal terminal D11 of the frequency converter UF, so that the frequency converter UF controls the motor M to adjust the speed to high speed;

[0057] 02:30 The control endpoint KTO contact disconnects the output, and the stirring motor M stops;

[0058] 04:00 The control endpoint KT0 contact closes and the stirring motor M starts;

[0059] At this time, the control terminal KT2 contact is closed and output, and the interlock relay KA2 is energized to output a medium-speed signal to the enable control signal terminal D12 of the frequency converter UF, so that the frequency converter UF controls the motor M to adjust the speed to the medium speed;

[0060] 04:40 The control endpoint KTO contact disconnects the output and the stirring motor stops;

[0061] 06:00 The control endpoint KT0 contact closes and outputs, and the stirring motor starts;

[0062] At this time, the control terminal KT3 contact is closed and output, the interlock relay KA3 is energized to output a low-speed signal to the enable control signal terminal D13 of the inverter UF, and the inverter controls the motor speed to a low speed;

[0063] 07:00 The control endpoint KTO contact disconnects the output, and the stirring motor M stops;

[0064] The time control program ends and waits for the next reset signal.

[0065] In addition, in a specific embodiment of the present invention, a digital tachometer of the crystallization tank stirring motor is provided in the local control box for real-time display of the motor speed, so that the operator can grasp the motor speed status at any time.

[0066] Meanwhile, in a specific embodiment of the present invention, operation and fault signal indicator lights (PGG, PGY) may be provided in the local control box, so that the operator can grasp the operation status of the variable frequency speed regulation system at any time.

[0067] After actual production testing, compared with the prior art, the control circuit of the present invention has low investment cost, convenient on-site operation, relatively simple automatic control logic, and no control deviation due to signal transmission interference or attenuation, and has a high cost performance.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A speed control circuit for a stirring motor of a pharmaceutical crystallization tank, the control circuit comprises a frequency converter, the stirring motor is a variable frequency motor, the frequency converter controls the operation of the stirring motor, characterized in that: The frequency converter is provided with a plurality of preset frequency values, and the frequency converter controls the stirring motor to operate at different speeds according to the selected frequency values, and the frequency converter has an enabling control signal terminal corresponding to the frequency value, and when the enabling control signal terminal is selected, the stirring motor is controlled to operate at the corresponding speed; The frequency converter has a power input terminal for receiving three-phase AC power, a drive output terminal connected to the stirring motor, and a main circuit composed of the stirring motor (M), the frequency converter (UF) and the three-phase AC power supply. In the main circuit, the AC power supply controls the operation of the stirring motor M (variable frequency motor) through the frequency converter (UF), and the frequency converter also has an interlock start-stop port. The frequency converter controls the start and stop of the stirring motor according to the connection state of the interlock start-stop port. The control circuit further includes an auxiliary control module, which mainly includes an interlocking start-stop switch circuit and a speed selection module. The interlocking start-stop switch circuit and the speed selection module are composed of relays. The normally open contacts of the relays respectively form a switch circuit with the interlocking start-stop port or the enable control signal terminal. One end of the relay coil is connected to the neutral line, and the other end is connected to the interlocking start-stop switch circuit or the speed selection module. The frequency number is three, corresponding to the three speeds of high, medium and low, respectively. The auxiliary control module also includes a time controller (KT), which has four output contacts for outputting control signals. The control signals are respectively a start-stop control output signal and three speed control output signals. The start-stop and speed control output times of the time controller can be programmed and set according to the production process flow. The start-stop control output signal and the control signal respectively control the power supply of the relay coil; The time controller has a reset pin, which is connected to a normally open reset switch (SBFT), and the auxiliary control module also includes a manual / automatic selection switch (SA1); The manual circuit of the interlocking start-stop switch circuit comprises a normally closed button as a manual stop switch SBF and a normally open button switch as a start button SBS connected in series, the other end of the start button SBS is connected to the start-stop relay KA coil, and the normally open end of the start-stop relay KA is connected in parallel with the start button SBS and the start-stop control terminal (KT1), so that the start-stop relay KA and the start button SBS form a self-locking start circuit; The frequency converter comprises a control operation indication switch K1 and a fault indication switch K2. When K1 is closed, the control operation indication light PGG is on.

2. According to a pharmaceutical crystallization tank stirring motor speed control circuit according to claim 1, one phase line in the AC power supply is connected to the power supply terminal L of the time controller through a fuse FU4, and the N terminal of the time controller is connected to the zero line of the power supply to form a power supply circuit.

3. A method for controlling the speed of a stirring motor of a pharmaceutical crystallization tank, using the speed control circuit of a stirring motor of a pharmaceutical crystallization tank as claimed in claim 1 or 2, characterized in that: A frequency converter (UF) is used to control the operation of the stirring motor, and three frequency constants are set in the internal module of the frequency converter (UF) and the program stored therein, so that different frequencies correspond to high, medium and low speeds respectively, and the speed of the stirring motor is controlled by outputting the enable control signal terminal of the frequency converter corresponding to the three frequencies.

4. A speed control method for a stirring motor of a pharmaceutical crystallization tank according to claim 3, characterized in that: Manual motor start and stop buttons (SBS, SBF) and a high, medium and low speed conversion switch SA are set in the local control box of the crystallizer to control the start and stop of the motor. At the same time, according to the crystallization process and material status, the relay (KA1, KA2, KA3) can select the action to give the inverter a high, medium and low trigger signal, so that the inverter UF can enter three different frequency states, thereby controlling the stirring motor M to enter the third speed.

5. A speed control method for a stirring motor of a pharmaceutical crystallization tank according to claim 4, characterized in that: According to the crystallization time period in the production process, a time controller KT is used to output contact control signals at the control endpoints (KT0-KT3) in different time periods. The contact control signals are connected to the start-stop control and the inverter speed control circuit, corresponding to the start-stop and high, medium and low speed control respectively. The start-stop and speed control output time of the time controller is programmed according to the production process.

6. A speed control method and circuit for a stirring motor of a pharmaceutical crystallization tank according to claim 5, characterized in that: The time controller restores the initial timing state of the time controller through the reset button SBFT.

Images