Device and method for reducing use amount of cleaning liquid for soaking MVR evaporator tube nest

Abstract

The invention relates to the technical field of evaporators, and discloses a device and method for reducing the use amount of a cleaning solution for soaking a tube nest of an MVR evaporator, and the method comprises the following steps: step 1, discharging materials in the MVR evaporator; 2, opening an electromagnetic pulse valve, discharging steam in the gas-liquid separator into the tube nest through a flushing pipe, and flushing the medicine scale on the inner wall of the tube nest by the steam; and step 3, controlling the electromagnetic pulse valve to enable the steam pulse to wash the tube nest. The steam is used for preliminarily cleaning the medicine scale in the tube nest, so that the subsequent washing and cleaning time and the cleaning liquid consumption can be reduced, and the steam temperature is higher than the drinking water temperature; the steam is gas, so that pressure impact can be formed in the process of washing the tube nest; and a pulse mode is further adopted, so that the flushing effect is improved, and the energy consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of evaporators, and in particular to a device and a method for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes. Background Art

[0002] MVR evaporator (mechanical vapor recompression evaporator) is a highly efficient evaporation equipment, widely used in chemical, pharmaceutical, food and other industries. Its core feature is to recover and reuse steam through the compressor, thus significantly reducing energy consumption.

[0003] The MVR evaporator includes a shell, a feed pipe is provided on the top of the shell, a heating chamber is provided below the feed pipe, a perforated plate and a tube array installed on the perforated plate are provided in the heating chamber, a concentrated liquid collection chamber is provided below the bottom perforated plate, and the concentrated liquid collection chamber is connected to a discharge pipe and a gas-liquid separation chamber. When the MVR evaporator is working, a negative pressure is formed in the tube array to facilitate the evaporation and concentration of the liquid. The gas and liquid in the tube array will enter the gas-liquid separation chamber for separation under the negative pressure. When the liquid medicine evaporates and concentrates in the tube array, the density of the liquid medicine increases and it is easy to adhere to the inner wall of the tube array, forming drug scale on the inner wall of the tube array. After each batch of production is completed, drinking water is used for heating and forced circulation to clean the drug scale on the tube array. However, due to the strong adhesion of the drug scale, it is difficult for the heated drinking water to soften the drug scale, resulting in unclean tube arrays. In order to solve the above problems, after the end of each week's production, alkali solution (sodium hydroxide solution) is used for heating and forced circulation to clean the tube scale. However, due to the existence of negative pressure, the alkali solution will be discharged into the bottom concentrate collection chamber and the discharge pipe. It is difficult for the tubes to be completely immersed in the alkali solution, resulting in poor cleaning effect of the tubes. Summary of the invention

[0004] The present invention aims to provide a device and method for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes, so as to solve the problem that the current tube scale is difficult to soften and clean, and the tube cleaning effect is relatively poor.

[0005] To achieve the above-mentioned purpose, the present invention provides a device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes, comprising a flushing pipe for conveying steam to the MVR evaporator tubes, one end of the flushing pipe is located above the MVR evaporator tubes, and the other end of the flushing pipe is connected to the exhaust port of a gas-liquid separator, and an electromagnetic pulse valve is provided on the flushing pipe.

[0006] Preferably, it also includes a cleaning liquid pipe, and a mixing valve is also provided on the flushing pipe. The electromagnetic pulse valve is located between the mixing valve and the MVR evaporator. The cleaning liquid pipe is connected to the mixing valve, and the cleaning liquid pipe is used to transport cleaning liquid or dry ice. Steam accelerates the sublimation of dry ice particles. After the dry ice particles contact the cleaning surface of the tube array, they instantly sublimate and expand, and collide with the medicine scale to produce gaps and cracks. The temperature difference is used to make the surface floating objects have a strong force at different contraction speeds, so that the medicine scale quickly and completely falls off the surface of the object, thereby achieving an efficient and safe cleaning effect; steam drives the cleaning liquid to flow, so that the pressure of the cleaning liquid increases during the flushing process, so that the cleaning effect of the tube array is enhanced.

[0007] Preferably, a liquid level regulating mechanism is further included, the liquid level regulating mechanism is located in the concentrated liquid collecting chamber of the MVR evaporator, the liquid level regulating mechanism is used to change the liquid level in the concentrated liquid collecting chamber, and a valve is provided on the discharge pipe connected to the concentrated liquid collecting chamber. When the cleaning liquid is injected into the array tubes to soak the array tubes, the valve on the discharge pipe is closed first, and then the liquid level in the concentrated liquid collecting chamber is raised by using the liquid level regulating mechanism, so that the size of the cleaning liquid filling space can be reduced, and the amount of cleaning liquid used when soaking the array tubes can be reduced.

[0008] Preferably, the liquid level regulating mechanism comprises an airbag or a telescopic folding member, and the liquid level in the concentrated liquid collection chamber can be quickly changed by changing the volume of the airbag or the volume occupied by the telescopic folding member.

[0009] Preferably, the airbag or telescopic folding member is provided in plurality, so as to facilitate rapid adjustment of the liquid level of the concentrated liquid collection chamber.

[0010] Preferably, the valve is a butterfly valve. A butterfly valve is a commonly used valve for regulating and cutting off fluid flow, which is easy to manufacture and maintain, usually lighter and easier to install.

[0011] Preferably, a steam compressor is also included, and the gas-liquid separator, the steam compressor and the flushing pipe are connected in sequence. The steam is further compressed by the steam compressor to increase the steam pressure, which has a better cleaning effect on the drug scale in the tube array.

[0012] In order to achieve the above object, the present invention also provides a method for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes, comprising the following steps:

[0013] Step 1: Discharge the material in the MVR evaporator;

[0014] Step 2: Open the electromagnetic pulse valve, and the steam in the gas-liquid separator is discharged into the tube array through the flushing pipe, and the steam flushes the medicine scale on the inner wall of the tube array;

[0015] Step 3: Control the electromagnetic pulse valve to allow steam pulses to flush the tubes.

[0016] Preferably, in step 2, cleaning fluid or dry ice is added to the flushing tube at the same time.

[0017] Preferably, the step 1 further comprises: closing a valve on a discharge pipe connected to the MVR evaporator, and reducing the volume of the liquid accommodating space in the concentrated liquid collecting chamber at the bottom of the MVR evaporator by means of a liquid level regulating mechanism.

[0018] Advantages of this solution:

[0019] 1. The steam temperature is higher than that of drinking water; and steam is a gas, which can form a certain pressure during the tube flushing process; the use of pulses can increase the flushing effect and save energy.

[0020] 2. Steam accelerates the sublimation of dry ice particles. After contacting the cleaning surface, they instantly sublimate and expand, and hit the medicine scale to create gaps and cracks. The temperature difference is used to make the floating objects on the surface shrink at different speeds, so that the medicine scale quickly and completely falls off the surface of the object, thereby achieving an efficient and safe cleaning effect; compressed air drives water or cleaning liquid, causing its pressure to increase during the flushing process, thereby enhancing the cleaning effect.

[0021] 3. By cutting off the pipeline between the evaporator and the gas-liquid separator, filling the bottom space of the MVR, and increasing the liquid level in the bottom concentrate collection chamber, the height of the cleaning liquid in the evaporator can be increased, so that the cleaning liquid can be soaked into the tubes, thereby achieving the purpose of softening the chemical scale, which is expected to alleviate the scaling of the tubes.

[0022] 4. Preliminary cleaning of the tube scale with steam can reduce the subsequent cleaning time and amount of cleaning fluid; after cleaning with steam, cleaning fluid / dry ice, the tubes are soaked in cleaning fluid, which greatly improves the cleaning effect of the tubes; the existing special cleaning method is to add about 2000L of 1% to 2% sodium hydroxide solution to soak the MVR. This solution greatly reduces the amount of cleaning fluid (sodium hydroxide solution) and gradually cleans to improve the cleaning speed of the scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0024] Figure 2 It is a schematic diagram of the local structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is further described in detail through specific implementation methods:

[0026] The reference numerals in the drawings of the specification include: flushing pipe 1, butterfly valve 2, discharge pipe 3, electromagnetic pulse valve 4, mixing valve 5, liquid level adjustment mechanism 6, shell 7, heating chamber 8, tube array 9, concentrate collection chamber 10.

[0027] Example:

[0028] A device for reducing the amount of cleaning liquid used for soaking the MVR evaporator tubes 9, as shown in the attached Figure 1 and attached Figure 2 As shown, it includes a flushing pipe 1 for conveying steam to the MVR evaporator tube 9. One end of the flushing pipe 1 is located in the shell 7 of the MVR evaporator, specifically above the tube 9 in the heating chamber 8. The other end of the flushing pipe 1 is connected to the exhaust port of the gas-liquid separator. An electromagnetic pulse valve 4 is provided on the flushing pipe 1. The electromagnetic pulse valve 4 has a fast switching speed and can achieve efficient control. The airflow can be controlled in a pulse manner to save energy.

[0029] It also includes a cleaning liquid pipe. A mixing valve 5 is also provided on the flushing pipe 1. The electromagnetic pulse valve 4 is located between the mixing valve 5 and the MVR evaporator. The cleaning liquid pipe is connected to the mixing valve 5. The cleaning liquid pipe is used to transport cleaning liquid or dry ice. Steam accelerates the sublimation of dry ice particles. After the dry ice particles contact the cleaning surface of the tube array 9, they instantly sublimate and expand, and collide with the medicine scale to produce gaps and cracks. The temperature difference is used to make the surface floating objects have a strong force at different contraction speeds, so that the medicine scale quickly and completely falls off the surface of the object, thereby achieving an efficient and safe cleaning effect; steam drives the cleaning liquid to flow, so that the pressure of the cleaning liquid increases during the flushing process, so that the cleaning effect of the tube array 9 is enhanced. The cleaning effect of the medicine scale of the tube array 9 is further enhanced by adding cleaning liquid or dry ice. The cleaning liquid in the scheme refers to a 1% to 2% sodium hydroxide solution, and the specific cleaning liquid is adjusted according to the corresponding medicine scale.

[0030] It also includes a liquid level regulating mechanism 6, which is located in the concentrated liquid collection chamber 10 of the MVR evaporator. The liquid level regulating mechanism 6 is used to change the liquid level in the concentrated liquid collection chamber 10. A valve is provided on the discharge pipe 3 connected to the concentrated liquid collection chamber 10. When injecting alkali solution into the array tubes 9 to soak the array tubes 9, first close the valve on the discharge pipe 3, and then use the liquid level regulating mechanism 6 to increase the liquid level in the concentrated liquid collection chamber 10, so that the size of the alkali solution filling space can be reduced, and the amount of alkali solution used when soaking the array tubes 9 can be reduced.

[0031] The valve is a butterfly valve 2, which is a commonly used valve for regulating and cutting off the flow of fluids. The butterfly valve 2 is easy to manufacture and maintain, and is usually lighter and easier to install.

[0032] Among them, the liquid level adjustment mechanism 6 is an airbag or a telescopic folding member. By changing the volume of the airbag or the volume occupied by the telescopic folding member, the liquid level in the concentrated liquid collection chamber 10 can be quickly changed. There are multiple airbags or telescopic folding members. Setting multiple airbags or telescopic folding members is convenient for quickly adjusting the liquid level of the concentrated liquid collection chamber 10. In this embodiment, two airbags or telescopic folding members are preferably set. The telescopic folding member shrinks when folded and increases when expanded to occupy the volume of the concentrated liquid collection chamber 7. For example, a cylinder piston structure or a bellows telescopic structure commonly used in the prior art can be used, which will not be described in detail.

[0033] It also includes a steam compressor, a gas-liquid separator, a steam compressor and a flushing pipe 1 which are sequentially connected. The steam is further compressed by the steam compressor to increase the steam pressure, so as to achieve a better cleaning effect on the drug scale in the tube array 9.

[0034] In order to achieve the above object, the present invention also provides a method for reducing the amount of cleaning liquid used for soaking the MVR evaporator tubes 9, comprising the following steps:

[0035] Step 1: Discharge the material in the MVR evaporator. The material here refers to the liquid medicine concentrated by the MVR evaporator.

[0036] The method also includes closing the valve on the discharge pipe 3 connected to the MVR evaporator, and reducing the volume of the liquid accommodating space in the concentrated liquid collection chamber 10 at the bottom of the MVR evaporator through the liquid level adjustment mechanism 6.

[0037] Step 2: Open the electromagnetic pulse valve 4, and the steam in the gas-liquid separator is discharged into the tube array 9 through the flushing pipe 1, and the steam flushes the drug scale on the inner wall of the tube array 9.

[0038] In this step, alkaline solution or dry ice is added to the flushing pipe 1 at the same time. Steam accelerates the sublimation of dry ice particles, which instantly sublimate and expand after contacting the cleaning surface, and hit the medicine scale to produce gaps and cracks. The temperature difference is used to make the floating objects on the surface have a strong force at different contraction speeds, so that the medicine scale quickly and completely falls off the surface of the object, thereby achieving an efficient and safe cleaning effect; compressed air drives the water or alkaline solution, so that the pressure increases during the flushing process, so that the cleaning effect is enhanced.

[0039] Step 3: Control the electromagnetic pulse valve 4 to allow steam pulses to flush the tube array 9.

[0040] This scheme first uses steam pulse to clean the tubes 9 for the first time, then adds alkali solution / dry ice steam to accelerate the sublimation of dry ice particles, which instantly sublimate and expand after contacting the cleaning surface, and collide with the drug scale to produce gaps and cracks. The temperature difference is used to make the surface floating objects have a strong force at different contraction speeds, so that the drug scale is quickly and completely removed from the surface of the object, thereby achieving an efficient and safe cleaning effect; compressed air drives water or alkali solution, so that its pressure increases during the flushing process, so that the cleaning effect is enhanced; finally, by cutting off the pipeline between the evaporator and the gas-liquid separator, filling the bottom space of the MVR, and increasing the liquid level in the bottom concentrated liquid gathering room, the alkali solution height in the evaporator can be increased, so that the alkali solution is soaked into the tubes 9, thereby achieving the purpose of softening the drug scale, and it is expected to alleviate the scaling of the tubes 9. The existing special cleaning method is to add about 2000L of 1% to 2% sodium hydroxide solution to soak the MVR. This scheme greatly reduces the amount of sodium hydroxide solution used and gradually cleans to improve the cleaning speed of the drug scale.

[0041] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical schemes and / or characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the technical scheme of the present invention. In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The scope of protection claimed in this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes, characterized in that: It comprises a flushing pipe for conveying steam to the MVR evaporator tubes, one end of the flushing pipe is located above the MVR evaporator tubes, the other end of the flushing pipe is communicated with the exhaust port of the gas-liquid separator, and an electromagnetic pulse valve is arranged on the flushing pipe.

2. The device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes according to claim 1, characterized in that: It also includes a cleaning liquid pipe, a mixing valve is also provided on the flushing pipe, the electromagnetic pulse valve is located between the mixing valve and the MVR evaporator, the cleaning liquid pipe is connected to the mixing valve, and the cleaning liquid pipe is used to transport cleaning liquid or dry ice.

3. The device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes according to claim 1, characterized in that: It also includes a liquid level regulating mechanism, which is located in the concentrated liquid collection chamber of the MVR evaporator and is used to change the liquid level in the concentrated liquid collection chamber. A valve is provided on a discharge pipe connected to the concentrated liquid collection chamber.

4. The device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes according to claim 3, characterized in that: The liquid level regulating mechanism comprises an air bag or a telescopic folding member.

5. The device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes according to claim 4, characterized in that: There are multiple airbags or telescopic folding parts.

6. The device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes according to claim 3, characterized in that: The valve is a butterfly valve.

7. The device for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes according to claim 1, characterized in that: It also includes a steam compressor, and the gas-liquid separator, the steam compressor and the flushing pipe are connected in sequence.

8. A method for reducing the amount of cleaning liquid used for soaking MVR evaporator tubes using the device of claim 1, characterized in that: The following steps are involved: Step 1: Discharge the material in the MVR evaporator; Step 2: Open the electromagnetic pulse valve, and the steam in the gas-liquid separator is discharged into the tube array through the flushing pipe, and the steam flushes the medicine scale on the inner wall of the tube array; Step 3: Control the electromagnetic pulse valve to allow steam pulses to flush the tubes.

9. The method according to claim 8, characterized in that: In the step 2, cleaning fluid or dry ice is added to the flushing tube at the same time.

10. The method according to claim 9, characterized in that: The step 1 further includes: closing the valve on the discharge pipe connected to the MVR evaporator, and reducing the volume of the liquid accommodating space in the concentrated liquid collecting chamber at the bottom of the MVR evaporator through a liquid level regulating mechanism.

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