WO2013164850A2

WO2013164850A2 - Equipment and method for filtration and degassing of solutions

Info

Publication number: WO2013164850A2
Application number: PCT/IN2013/000189
Authority: WO
Inventors: Ashish Bhavendra VAISHNAV
Original assignee: Vaishnav Ashish Bhavendra
Priority date: 2012-03-26
Filing date: 2013-03-21
Publication date: 2013-11-07
Also published as: WO2013164850A3

Abstract

The present invention relates to an equipment and method for the filtration and degassing of solutions. It provides easy and fast filtration of solutions and can be used for continuous filtration of large quantities of solutions easily. It is made of SS316 steel and is compatible for using both 47 mm and 90 mm filters. Filtration in this equipment can be performed automatically or manually as required. It can be used for the filtration of laboratory solvents, cell culture media, ophthalmic products, pharmaceuticals, vitamins, process water, antibiotics and photo resists. Both filtration and degassing of mobile phase to be used in HPLC can be done using this equipment. The present invention is a high efficiency, versatile filtration device designed for vacuum/positive pressure filtration of liquids.

Description

TITLE OF THE INVENTION:

Equipment and method for filtration and degassing of solutions

FIELD OF THE INVENTION:

The present invention relates to a filtration unit which is useful for the filtration and degassing of solutions used in laboratories and its mode of operation.

BACKGROUND OF THE INVENTION:

Filtration is a process for separation of insoluble material from a solution. It is commonly a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which only the fluid can pass. Filtration is used to separate particles and fluid in a suspension, where the fluid can be a liquid, a gas or a supercritical fluid. Filtration equipment for rapid and easy filtration is of great help for laboratory chemist for the separation of materials of different chemical composition. Filtration is also important and widely used as one of the unit operations of chemical engineering. Filtration device is mainly essential in

1. Process development laboratories in R&D

2. Analytical laboratories in Q.C.

3. Microbiology Laboratories in Q.C.

4. Production departments of chemical and pharmaceutical organizations

Both filtrate and the retainate may be useful to the user on case to case basis. The volume of filtration varies from micro liter to kiloliter when the filtrate is to be used and from microgram to kilogram when retainate is to be used. Moreover in some applications, filtration is to be carried out in sterile conditions. For this application, pre-sterilized or autoclavable filtration devices are required. Depending on the requirements, there are many different methods of filtration which aim to attain the separation of substances. The substance that is to pass through the filter must be a fluid, i.e. a liquid or gas. Methods of filtration vary depending on the location of the targeted material.

US Patent 6309444 describes a Post Blending valve degasser which has a flow-through vacuum degassing unit for degassing a mobile phase. This unit includes a vacuum conduit adapted to be connected to a source for creating a vacuum in the conduit, an inlet port and an outlet port for admitting and discharging the mobile phase to be degassed, a degassing tube for conducting the mobile phase through the conduit, wherein the degassing tube is of a gas-permeable, liquid impermeable material.

US Patent 6837992 discusses an integrated apparatus for degassing and blending multiple mobile phase streams which has an integrated mobile phase degassing and blending apparatus for transport of liquid chromatography fluids. The first portion of the invention consists of an enclosed degassing chamber while the second portion includes a mobile phase blending device. Both these devices are coupled to one another such that the liquid chromatography fluids pass directly into the blending device from the degassing chamber.

US Patent 6596058 provides a film degassing system which has a flow-through vacuum degassing unit for degassing a mobile phase in liquid chromatography applications. This unit contains a flat self-supporting thin membrane which is gas permeable and liquid impermeable, disposed in a compact degassing component, to selectively degas a mobile phase. The self- supporting thin membrane is disposed on a permeable substrate through which vacuum is drawn by a connected vacuum source. DE 3519265 gives a filtration system coupled to a reactor comprising automatic sample inlet for processing and analyzing samples from fermentation processes where the filtration appliance is linked to a process control computer which is used for the fully automatic detection of the filtration properties of a wide variety of biosuspensions and for coupling automatic analyzers with bioreactors. The appliance comprises a filtration unit with an automatically conveyed filter belt, a photometric measuring device for detecting filter cake growth, a weighing appliance for the filtrate and the infeeds and valves for automatic charging, emptying, cleaning, sterilization of the sample infeed, and appliances for transferring the filtrate into automatic analyzers (for example HPLC). The preferred field of application of the filtration appliance is in the computer- linked monitoring and control of fermentation processes, this being an area where hitherto there has been a lack of reliable automatic processes for the important key variables such as, for example, concentration of biomass, nutrient substrates and metabolic products. The concept, on which the design of the appliance is based, that of discontinuous cake filtration in the non-sterile range, ensures the required reliability in terms of the risk of contamination for these processes. The constructional details of the appliance permit, in particular, its use for separating systems having extremely high viscosities and ensure the required purity of the filtrate for connecting automatic analyzers.

WO 2011031333 describes apparatus and methods for changing the concentration of gases in liquids which comprises a flow chamber through which the liquid is passed and which comprises a wall comprising a planar separation membrane, the separation membrane being substantially impermeable to the liquid and permeable to the selected gas, characterized in that the separation member extends beyond the flow chamber and provides a seal between components of the apparatus. The apparatus is particularly useful for degassing liquids, for example HPLC eluents and analysis samples.

JP 09-173794 discusses a multistage semipermeable membrane system and process for using the same which describes a system which comprises: (a) introducing a first liquid stream Q2 of a main eluted fraction containing target molecules to be concentrated and a solvent into a first semipermeable filtration membrane unit for concentrating and recovering the objective molecules at the supply side of this unit; (b) introducing a second liquid stream Q3 of another eluted fraction containing contaminants and the solvent into a second semipermeable filtration membrane unit for concentrating and collecting the contaminant solute at the supply side of this unit; and (c) introducing a filtered solvent stream Q9 from the permeation downstream side of the first semipermeable filtration membrane unit into the supply side of the second semipermeable filtration membrane unit. This system is mainly used for concentrating a highly valuable solute and refining a used solvent, wherein the solute and solvent are produced in a preparative liquid chromatography (in particular, high performance liquid chromatography (HPLC)), and provide the process using this system.

JP 07-260761 describes a container for storing liquid where a container is provided for storing liquid (solvent feeding container for a mobile phase), which is suitable for storing or feeding solvent for the mobile phase, which is especially used in chromatography. This container consists of an opening part dedicated for a suction pipe for solvent A for a mobile phase is formed at the upper part of a container. At the same time, one or more other opening parts, where a solvent feeding pipe, a gas bubbling pipe or an inactive-gas introducing pipe and the like are arranged, are formed. Meanwhile, the bottom face of the container is made to be the cone shape. A recess part, wherein the tip part of the suction pipe can be inserted, is formed at the bottom face part. Because a plurality of the opening parts are provided, the feeding work of the new solvent A into the container, the degassing work of the solvent A, the displacement work of the air in the container and the like can be independently performed without the interruption of the sucking work (analyzing operation) of the solvent A. Because the recess part is formed, the entire solvent can be sucked up without residue.

Filtration devices essentially consist of the following parts:

1. Filtration funnel

2. Vacuum flask or collector vessel

3. Vacuum / Pressure pump

4. Filter paper

Conventional filtration devices consist of glass or stainless steel filtration funnels and vacuum flasks which get attached to a vacuum pump. Assembling the filter funnel and the vacuum flask is time consuming and cumbersome due to the fragile nature of glass or the heavy weight of the stainless steel funnel. Moreover, the collection flask is of a limited volume due to which large volume filtration requires manual presence for repeated emptying of the filtrate. So a new^* equipment which provides easy and fast filtration of large quantities of solutions and provides degassing of the solution whenever needed, is the need of the day.

OBJECT OF THE INVENTION:

The main object of the invention is to provide for an equipment and method for filtration and degassing of solutions used in laboratories.

Another object of the invention is to provide for an equipment and method for the filtration and degassing of solutions used in laboratories which provides easy and fast filtration. Still another object of the invention is to provide for an equipment and method for the filtration and degassing of solutions used in laboratories which can filter large volumes of solution without manual intervention.

SUMMARY OF THE INVENTION:

The present invention is an equipment and method for the filtration and degassing of solutions used in laboratories. Easy and fast filtration of large volumes of solutions can be achieved by this invention. The equipment is made of stainless steel and is compatible with both 47mm and 90 mm filters. Filtration can be carried either with positive pressure or by applying vacuum. Manual intervention is not essentially required during the filtration process thus saving manpower.

DETAILED DESCRIPTION:

The nature of the invention and the manner in which it is performed is clearly described in the specification. The invention has various components and they are clearly described in the following pages of the complete specification.

Filtration is a process very common to all laboratories, be it chemical, instrumental, microbiology or others. Filtration, as a physical operation is very important in chemistry for the separation of materials of different chemical composition. A solvent is chosen which dissolves one component, while not dissolving the other. By dissolving the mixture in the chosen solvent, one component will go into the solution and pass through the filter, while the other will be retained. This is one of the most important techniques used by chemists to purify compounds. In HPLC, sample and mobile phase filtration are simple, economical practices that serve to extend the life of consumable HPLC parts, decrease system wear and tear, and preserve the integrity of the HPLC system. Frequent mobile phase degassing reduces erratic pump delivery of the solvent due to pressure fluctuations, and hence reduces detector noise. Degassing also removes dissolved oxygen that can result in oxidative degradation of the sample and mobile phases, and reduces the sensitivity and operating stability of ultra-violet, refractive index, electrochemical and fluorescence detectors. By filtering mobile phase, analysts can reduce debris capable of plugging the sinker and column frits, causing contamination, damaging pump valves, blocking capillaries, causing poor peak performance, and contributing extra peaks and excessive chromatographic noise.

The present invention can be used for the filtration as well as the degassing of large quantities of mobile phase without the cumbersome procedures of repeated assembling of the conventional filtration device. Moreover, as the filtration and degassing is performed automatically, manual presence isn't required during the process.

In microbiology laboratories, filtration is used to purify cell cultures as well as for assays of antibiotics and vitamins. The filtrations performed in the microbiology laboratory are highly prone to contamination and need to be performed in sterile conditions. So a sterilizable filtration unit would be preferred for the same.

The present invention is a filtration equipment made of stainless steel which is readily sterilizable. Moreover, filtration is carried out in closed conditions thus eliminating the chances of contamination.

Even in production units, large volumes of water used in the process needs to be filtered. Manual presence would be needed for this filtration which causes wastage of manpower. To avoid this, automatic filtration equipment which can continuously filter large volumes of solutions would be preferred. The present invention is an automatic filtration equipment which can continuously filter large volumes of solutions without the need for manual presence.

The present invention is a filtration equipment which can provide easy and fast filtration of large volumes of solutions. It provides relief from the cumbersome conventional filtration device and reduces the time taken for filtration of large quantity of solutions in the laboratory. It is made of SS316 steel which is unbreakable and so is highly robust. The inner walls of the equipment can be coated using non-metals like Teflon or Silicon as per the requirement. It is compatible for using both 47 mm and 90 mm disc filters. It can be operated manually or automatically as needed. It is also proved to be compatible with MOC.

The present invention can be used with a variety of aggressive chemicals, solvents, reagent and solutions including gases and liquids as it is made of non-reactive and robust stainless steel. It is recommended for the filtration of products such as laboratory solvents, cell culture media, ophthalmic products, pharmaceuticals, vitamins, process water, antibiotics and photo resists.

During filtration, fluids flow through a filter. This flow may vary due to a difference in pressure or due to the application of vacuum. Vacuum applied on the filtrate side makes the process of filtration faster. The present invention filters using both, positive pressure as well as by the application of vacuum.

The present invention is a complete system which has in it a reservoir for the raw solution as well as a collection vessel for the filtered product to be used. The raw solution reservoir is connected to the filtration device through an inlet at the top. The solution to be filtered is transferred to the membrane inside the filtration device either by positive pressure or by applying vacuum through the port in the filtration device. The filtrate which passes through the membrane is collected in the collection vessel. Different sizes of collection tanks are available as per requirement. In this equipment there is an option available with a sonicator attachment for degassing of filtrate. Transducer is provided for high frequency of degassing of product as per system capacity. Degassing in this equipment can be carried out for a maximum of 20 minutes which is more than the prevailing required time for degassing. The filtrate can be taken out from the collection vessel through the outlet provided at the bottom. Continuous filtration of the solution can be carried out using this filtration equipment. Repeat filtration can be carried out using a fresh membrane filter.

The present invention is a high efficiency, versatile filtration device designed for vacuum filtration of liquids. The vacuum pump is connected to the system through a silicone tube. The whole equipment conforms to GMP and GEP specifications applicable for pharmaceutical, sanitary, sterile area, labs and other industries. The performance of the system is tested by applying a pressure of 5.0 kg/cm² to check leakage. The material used for the construction of the equipment is S.S. of AISI 316/316L quality. All joints in this equipment are argon welded with super finishing. The whole system is constructed of stainless steel and is designed for providing, integrating or storing harmful, highly pure or combustible solutions. The nozzle and dead corners are reduced to an absolute minimum to avoid accumulation of the solution at any spaces. The internal and the external walls as well as the base of the equipment are mirror polished to 240 grit finish. An outlet nozzle is provided with T.C.end blind and an option is available for Hose nipple connection.

The present invention can be used to sterilize liquids or gases by pressure filtration through a 47 & 90 mm diameter disc filter of suitable pore size. The equipment is fitted with a vacuum pump and all its components are compatible with using vacuum. The product pot is connected with a silicon tube to the product inlet nozzle for suction and filtration of the product. As soon as the vacuum pump starts, the product is transferred to the cone vessel by the vacuum system.

Figs. 1 , and 2 describe the present invention of different types within the 2.0 L capacity. The labeled numbers in the figs, are described as follows in Table 1 along with their material of construction (MOC) and their size.

Table 1

Figs. 3, and 4 describe the present invention of different types within the 5.0 L capacity. The labeled numbers in the figs, are described as follows in Table 2 along with their material of construction (MOC) and their size.

Table 2

The present invention can be constructed of different capacities and different types. A few of these variations are explained in the following examples:

Example 1

As shown in Fig. 1, a filtration equipment of a capacity of 2.0 liters can be constructed which has the semi-automatic system of filtration. This system comprises of three major parts namely Top Cover, Membrane Base and Collection Tank of 2.0 liters volume as shown in the Fig. 1. The transducers for sonicator are fitted under the Collection Tank. The material of construction and the size specifications of each part of the filtration equipment of this variation are described above in Table 1.

For filtration, the filter membrane to be used is placed on the membrane base and the product inlet nozzle is connected to the container of the liquid to be filtered through a silicone tube. Vacuum is applied through the vacuum inlet nozzle provided in the collection tank. The filtrate passes through the filter membrane and is collected in the collection tank. The vacuum pump has to be switched off once the desired volume of liquid is filtered. A maximum of 2 liters of filtrate can be collected at one go. The required volume of filtrate is then taken out through the outlet of the collection tank.

For filtration using positive pressure, the solution is stored in a pressure vessel and pressure is applied through nitrogen gas. The solution under pressure enters the system through the silicone tube connected to the product inlet nozzle. If needed, degassing of the collected filtrate filtered by any of the above mentioned methods, can be done by switching on the sonicator which is programmed to run for a maximum of 20 minutes in one run.

Example 2

As shown in Fig. 2, a filtration equipment of a capacity of 2.0 liters can be constructed which has the automatic system displaying the levels of filtration. This system comprises of three major parts namely Top Cover, Membrane Base and Collection Tank of 2.0 liters volume as shown in Fig. 2. The transducers for sonicator are fitted under the Collection Tank. The material of construction and the size specifications of each part of the filtration equipment of this variation are described above in Table 1. For filtration, the filter membrane to be used is placed on the membrane base and the product inlet nozzle is connected to the container of the liquid to be filtered through a silicone tube. Vacuum is applied through the vacuum inlet nozzle provided in the collection tank. The filtrate passes through the filter membrane and is collected in the collection tank. High and low levels of control valves are provided in the collection tank for automatic on/off control of the vacuum pump to avoid overflow of the filtrate as well as to avoid manual attention. A maximum of 2 liters of filtrate can be collected at one go. The required volume of filtrate is then taken out through the outlet of the collection tank.

Example 3

As shown in Fig. 3, a filtration equipment of a capacity of 5.0 liters can be constructed which has the semi-automatic system of filtration. This system comprises of three major parts namely Top Cover, Membrane Base and Collection Tank of 5.0 liters volume as shown in the Fig. 3. The transducers for sonicator are fitted under the Collection Tank. The material of construction and the size specifications of each part of the filtration equipment of this variation are described above in Table 2.

For filtration, the filter membrane to be used is placed on the membrane base and the product inlet nozzle is connected to the container of the liquid to be filtered through a silicone tube. Vacuum is applied through the vacuum inlet nozzle provided in the collection tank. The filtrate passes through the filter membrane and is collected in the collection tank. The vacuum pump has to be switched off once the desired volume of liquid is filtered. A maximum of 5 liters of filtrate can be collected at one go. The required volume of filtrate is then taken out through the outlet of the collection tank.

Example 4

As shown in Fig. 4, a filtration equipment of a capacity of 5.0 liters can be constructed which has the automatic system displaying the levels of filtration. This system comprises of three major parts namely Top Cover, Membrane Base and Collection Tank of 5.0 liters volume as shown in the Fig. 4. The transducers for sonicator are fitted under the Collection Tank. The material of construction and the size specifications of each part of the filtration equipment of this variation are described above in Table 2.

For filtration, the filter membrane to be used is placed on the membrane base and the product inlet nozzle is connected to the container of the liquid to be filtered through a silicone tube. Vacuum is applied through the vacuum inlet nozzle provided in the collection tank. The filtrate passes through the filter membrane and is collected in the collection tank. High and low levels of control valves are provided in the collection tank for automatic on/off control of the vacuum pump to avoid overflow of the filtrate as well as to avoid manual attention. A maximum of 5 liters of filtrate can be collected at one go. The required volume of filtrate is then taken out through the outlet of the collection tank.

The present invention is easy to use, easily sterilizable, can be used in all laboratories without the requirements of presence of personnel while filtration, continuously filters large quantities of solutions and is highly economical.

Although the preferred embodiment as well as the construction and use have been specifically described, it should be understood that variations in the preferred embodiment could be achieved by a person skilled in the art without departing from the spirit of the invention. The invention has been described with reference to specific embodiment which is merely illustrative and not intended to limit the scope of the invention as defined in the claims.

Claims

I claim,

1. Equipment and method for filtration and degassing of solutions wherein continuous filtration and degassing of solutions can be achieved without the requirement of presence of personnel during the process of filtration.

2. The equipment and method for filtration and degassing of solutions as claimed in claim 1 wherein a large quantity of solution can be filtered at one go without the need of repeated decantation of filtrate and repeated changing of the filter discs.

3. The equipment and method for filtration and degassing of solutions as claimed in claim 2 wherein the filtration equipment is compatible for using both 47 mm and 90 mm disc filters.

4. The equipment and method for filtration and degassing of solutions as claimed in claim 1 wherein the filtration equipment is made of AISI 316 stainless steel which is unbreakable and so is highly robust and if required its internal walls can be coated with non-metals like Teflon or Silicon.

5. The equipment and method for filtration and degassing of solutions as claimed in claim 4 wherein the filtration equipment can be used with a variety of aggressive chemicals, solvents, reagents and solutions including gases and liquids as it is made of non-reactive and robust stainless steel.

6. The equipment and method for filtration and degassing of solutions as claimed in claim 1 wherein the whole equipment being made of stainless steel is completely sterilizable and the process of filtration is carried out in closed conditions thus eliminating the risks of contamination.

7. The equipment and method for filtration and degassing of solutions as claimed in claim 1 wherein filtration can be carried out by either using positive pressure or by applying vacuum.

8. The equipment and method for filtration and degassing of solutions as claimed in claim 1 wherein the equipment is a complete system having a reservoir for the raw solution as well as a collection vessel for the filtered product.

9. The equipment and method for filtration and degassing of solutions as claimed in claim 8 wherein the raw solution reservoir is connected to the filtration device through an inlet at the top.

10. The equipment and method for filtration and degassing of solutions as claimed in claim 9 wherein the solution to be filtered is transferred to the membrane inside the filtration device either by positive pressure or by applying vacuum through the port provided in the filtration device.

11. The equipment for filtration and degassing of solutions as claimed in claim 10 wherein the filtrate which passes through the membrane is collected in the collection vessel.

12. The equipment for filtration and degassing of solutions as claimed in claim 11 wherein different sizes of collection tanks are available as per requirement.

13. The equipment for filtration and degassing of solutions as claimed in claim 12 wherein the sonicator usage is optional and is used only if the degassing of solutions is needed.

14. The equipment for filtration and degassing of solutions as claimed in claim 13 wherein transducers are provided for high frequency of degassing of product as per the system capacity.

15. The equipment for filtration and degassing of solutions as claimed in claim 14 wherein degassing can be carried out for a maximum of 20 minutes continuously.

16. The equipment for filtration and degassing of solutions as claimed in claim 15 wherein filtrate can be taken out from the collection vessel through the outlet provided at the bottom.

17. The equipment for filtration and degassing of solutions as claimed in claim 16 wherein repeated filtration can be carried out using a fresh membrane filter.

18. The equipment for filtration and degassing of solutions as claimed in claim 1 wherein the equipment conforms to GMP and GEP specifications applicable for pharmaceutical, sanitary, sterile area, labs and other industries.

19. The equipment for filtration and degassing of solutions as claimed in claim 1 wherein the performance of the system is tested by applying a pressure of 5.0 kg/ cm² to check leakage.

20. The equipment for filtration and degassing of solutions substantially herein described with reference to the foregoing description and diagrams.