IE68669B1 - Improvements in and relating to mixing systems - Google Patents

Abstract

Apparatus for manufacturing a liquid preparation includes a mixer (6) for breaking up lumps of solids materials or for dispersing a viscous liquid to enable the solid material or viscous liquid to be fed in a freee-flowing form via an auxiliary feed line (12) to a manufacturing loop. The loop comprises a primary feed line (14) for receiving base liquid from a suitable supply, a secondary feed line (15) for ingredients and a blender (4) for mixing the ingredients, including the suspended or dispersed solids material or viscous liquid, in the base liquid. The auxiliary feed line (12) is connected to the loop upstream of the blender (4). The apparatus enables lumpy solid material or viscous liquid ingredients to be added in free-flowing form to a preparation as part of an in-line process.

Description

IMPROVEMENTS IN AND RELATING TO MIXING SYSTEMS The present invention relates to a mixing system and in particular to a mixing system for liquid pre-mixes or liquid products.

Certain manufacturing methods for preparing liquid pre-mixes or liquid products advantageously use a mixing system, based on re-circulation of liquid through an in-line mixing and solids addition system. In the pharmaceutical and food manufacturing sectors, where there are stringent quality standards to be met, the use of a closed mixing system is required. In other industries, open or closed systems are employed, as required by the particular product.

Typical mixing systems for liquid products receive liquid from a manufacturing vessel and pump it to a venturi assembly, at which point other ingredients such as dry powder are dosed in from a hopper. The liguid/powder mix is then blended to disperse the ingredients. The product may then be transferred to other processing or packaging steps, or alternatively recirculated through the manufacturing vessel and venturi assembly until the desired concentration of dispersed ingredients is reached.

Examples of suitable equipment for this process include the INSTA-BLEND mixer, manufactured by Advanced Dispersers and the XYCLON mixer, manufactured by Ytron-Quadro.

A difficulty which exists with the above mixing system is that only free-flowing dry materials may flow readily from the hopper to the venturi assembly, whereas many dry ingredients used in such system contain lumps of up to 3 cm diameter or even greater which do not flow freely in the mixing lines. The dry ingredients may even settle into 6866? blocks during storage. Therefore, prior to use in the manufacturing process, the lumps or blocks of dry material require to be mechanically broken up or pulverised before being added to the hopper. This results in higher manufacturing costs, higher risk of contamination of the ingredient and higher risk of release of ingredients to the environment, with consequent reduction in efficiency of manufacture and health risks. The problem is exacerbated in the case of hygroscopic ingredients which may become lumpy while in the hopper as a result of water-uptake and which as a result fail to feed efficiently from the hopper to the venturi assembly. A similar difficulty results where the ingredient to be added from the hopper is a viscous liquid.

An object of the present invention is to alleviate the above disadvantage and to provide an efficient in-line mixing system capable of accepting lumpy, solid or viscous liquid ingredients.

The present invention accordingly provides an apparatus for manufacturing a liquid preparation, the apparatus comprising (i) a primary feed line for receiving a base liquid from a manufacturing vessel, the primary feed line forming a loop connectable with the manufacturing vessel; (ii) at least one other feed line connecting an ingredient > supply means to the loop; and I (iii) blending means in the loop for dispersing each ingredient in the base liquid, characterised in that the apparatus includes (iv) an auxiliary feed line separate from the primary and the at least one other feed line, the auxiliary feed line having receiving means for at least one supplementary ingredient and incorporating mixing means, the auxiliary feed line being connectable to the loop upstream of the blending means to mix and subsequently to supply said supplementary ingredient in liquid or suspended form to the loop.

The invention also provides a process for manufacturing a liquid preparation comprising - feeding a base liquid from a manufacturing vessel to a primary feed line which forms a loop connectable with the manufacturing vessel, feeding at least one ingredient from at least one other feed line connected to the loop, dispersing each ingredient in the base liquid by blending means in the loop, - supplying at least one supplementary ingredient to receiving means provided in an auxiliary feed line separate from the at least one other feed line, the receiving means incorporating mixing means, the auxiliary feed line being connectable to the loop upstream of the blending means to mix and to supply said supplementary ingredient in liquid or suspended form to the loop.

In a preferred embodiment means are provided for diverting at least a portion of the base liquid to the auxiliary feed line for mixing with the or each supplementary ingredient in the receiving means.

The apparatus and method of the invention permit lumpy solid material or viscous liquid to be received in-line in the manufacture of a liquid preparation and enable that lumpy solid or viscous material to be suspended or dispersed in the base liquid.

The invention will now be described more particularly by reference to the accompanying drawing which shows one embodiment of an in-line mixing apparatus according to the invention.

The drawing is a schematic representation of equipment suitable for manufacturing a liquid pharmaceutical product or pre-mix. Base liquid is drawn through an inlet 1 into a manufacturing vessel 2 by a pump 3. From there, the liquid passes along a primary feed line 14 having a venturi assembly 4 which acts as a blender. If any component to be used in the manufacturing process is a lumpy or solid material or a viscous liquid, this component is charged batch-wise or continuously into a pre-mixing vessel 5, provided with a shear mixer 6. The pre-mixing vessel is provided with a closable lid or port 13 through which the solid material or viscous liquid can be added. On opening a valve 7, some or all of the liquid is diverted from the main circulation line into the charged pre-mixing vessel 5 and blended to form a pre-mix by the sheaf mixer 6, which breaks up and/or disperses the solid material or viscous liquid thoroughly. The pre-mix is then routed out of the pre-mixing vessel 5 to the venturi assembly 4, by way of an auxiliary feed line 12, an outlet 8 from the hopper 9 and the feed line 15. Any required additional free flowing dry or liquid ingredients can be fed from the hopper 9. On emerging from the venturi assembly 4, the product is passed in the normal way through the line and is returned to the manufacturing vessel 2 for recirculation either directly to the manufacturing vessel 2 or via the pre-mixing vessel 5 as required. Once components from the pre-mixing vessel 5 and/or the hopper 9 have been added to the desired concentration and adequately suspended or dispersed, the product is pumped to downstream processing and/or packaging stations. The apparatus includes a cleaning-in-place loop 11, as is usual in such equipment.

Release of liquid to the pre-mixing vessel 5 is controlled by the valve 7. Release of liquid pre-mix from the pre-mixing vessel 5 is controlled by the valve 10. The pre-mix may be prepared and added by a batch process or alternatively as a continuous process and for this purpose an appropriate sensor may be provided at any suitable point between the outlet from the pre-mixing vessel 5 and the inlet to the venturi assembly 4. It is also envisaged that the pre-mix may be fed into the hopper 9 and thence to the venturi assembly 4. Where the material to be pre-mixed is a viscous liquid, pre-mixing with the liquid from the manufacturing vessel 2 avoids the necessity of slowing the process down to allow the required amount of viscous liquid to flow in from the hopper 9, or of pumping the viscous liquid to the venturi assembly 4. Instead, the viscous material is pre-diluted to a free-flowing concentration which passes readily into and through the venturi assembly 4.

The apparatus can also be used to prepare non-aqueous liquid pre-mixes independently of the liquid from the manufacturing vessel 2, for subsequent addition through the hopper 9 or venturi assembly 4. In that case, with valve 7 closed, the liquid materials are added directly to the pre-mixing vessel 5 and blended by the mixer 6. The so-prepared liquid pre-mix may then be fed directly to the hopper 9 or via valve TO to the venturi assembly 4.

The apparatus may be provided with an in-line mixer downstream of the venturi assembly 4 if this is required to disperse the ingredients adequately.

Use of the apparatus according to the invention results in significant improvement in effectiveness and in cost saving. Furthermore, in the closed system described, the risk of contamination of the ingredients is reduced, as is the risk of contamination of the environment by the ingredients. Where the manufacturing process is for the preparation of a pharmaceutical pre-mix or product, the process and apparatus described constitute pharmaceutical good manufacturing practice. Moreover, the disadvantages associated with mechanical size reduction of solid ingredients are avoided. In particular, size reduction of the solids under liquid conditions avoids heat generation which would otherwise occur on mechanical working. Any such heat could result in decomposition of the ingredients and would not be tolerable in the manufacture of pharmaceuticals. Additionally, mechanical working to pulverise solids inevitably results in dust production and such dust could be harmful to workers.

While the apparatus has been described particularly in relation to a closed system, it will be appreciated that it is equally suitable for use in manufacturing processes which do not require careful control of ingredient quality or process containment and which can therefore more conveniently and cheaply be carried out with open vessels.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention as defined in the appended claims.

Claims (8)

1. T. Apparatus for manufacturing a liquid preparation, the apparatus comprising (i) a primary feed line for receiving a base liquid from a manufacturing vessel, the primary feed line forming a loop connectable with the manufacturing vessel; (ii) at least one other feed line connecting an ingredient supply means to the loop; and (iii) blending means in the loop for dispersing each ingredient in the base liquid, characterised in that the apparatus includes (iv) an auxiliary feed line separate from the primary and the at least one other feed line, the auxiliary feed line having receiving means for at least one supplementary ingredient and incorporating mixing means, the auxiliary feed line being connectable to the loop upstream of the blending means to mix and subsequently to supply said supplementary ingredient in liquid or suspended form to the loop.

2. Apparatus according to claim 1, in which the mixing means comprises a static mixer capable of receiving said at least one supplementary ingredient in the form of lumpy solid material and of breaking up the lumpy solid material to render it dispersable in liquid.

3. Apparatus according to claim 1 or claim 2, including means for diverting at least a portion of the base liquid to the auxiliary feed line.

4. A process for manufacturing a liquid preparation comprising 5. - feeding a base liquid from a manufacturing vessel to a primary feed line which forms a loop connectable with the manufacturing vessel, ( feeding at least one ingredient from at least one 10 other feed line connected to the loop, dispersing each ingredient in the base liquid by blending means in the loop, 15 - supplying at least one supplementary ingredient to receiving means provided in an auxiliary feed line separate from the at least one other feed line, the receiving means incorporating mixing means, the auxiliary feed line being connectable to the loop 20 upstream of the blending means to mix and to supply said supplementary ingredient in liquid or suspended form to the loop.

5. A process according to claim 4, including receiving 25 said at least one supplementary ingredient in the form of a lumpy solid material and breaking up the lumpy solid material to render it dispersable in liquid.

6. A process according to claim 5, including diverting 30 at least a portion of the base liquid to the auxiliary feed line.

7. Apparatus for manufacturing a liquid preparation, substantially as herein described with reference to the 35 accompanying drawing.

8. A process for manufacturing a liquid preparation substantially as herein described with reference to the accompanying drawings.