GB1594264A

GB1594264A - Batch mixing installation

Info

Publication number: GB1594264A
Application number: GB14997/77A
Authority: GB
Original assignee: Baker Perkins Holdings Ltd
Current assignee: Baker Perkins Holdings Ltd
Priority date: 1977-04-12
Filing date: 1977-04-12
Publication date: 1981-07-30
Also published as: FR2387075A1; DK161278A; DE2816351A1; NL7803804A; ZA782119B; NO781282L; FR2387075B1; SE7803788L

Description

(54) BATCH MIXING INSTALLATION (71) We, BAKER PERKINS HOLDINGS LIMITED, a British Company, of Westfield Road, Peterborough PE3 6TA, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a batch mixing installation in which ingredients to be mixed are deposited either into a bowl-like mixing container and the container is then brought into engagement with a batch mixer having a mixing element protruding into the mixing container or are deposited into a closed container and mixed by rotation of the container as a whole.The installation is particularly suitable for use in mixing bakery dough constituents and it is desirable to provide a system offering the facility for optimizing mixer and mixing container utilization over a given time period.

According to the present invention, there is provided a batch mixing installation as set forth in Claim 1.

The installation can be operated with a pair of mixing containers and can be used as set forth in Claim 14, a preferred operating cycle being set forth in Claim 2. The cycle can be repeated with the mixing containers being alternately charged, mixed and discharged. Using this installation a 30% reduction in cycle time can be achieved. Furthermore by using the reversible conveying means, less space can be occupied than using conveying means for conveying the mixing containers always in the same direction around a closed path.

If the mixing container is a bowl, the mixing station can consist of a conventional type of batch mixer employing a depending mixing element, and the transfer means can be a lifting mechanism for lifting successive mixing containers up into position around the mixing element. If on the other hand, the mixing container is closed, such as the ball mill containers used for mixing say paints, the mixing station can consist of a drive mechanism for rotating the mixing container as a whole.

The invention is particularly useful when applied to mixing bakery dough, and a preferred installation is set forth in Claim 4.

The installation is preferably arranged for wheeled mixing containers which can be pushed along the floor, either directly on the floor if the floor is sufficiently even, or on say flat plates or guides or rails placed on the floor; the conveying means are preferably for conveying and guiding the mixing containers while the mixing containers continue to be supported by the floor. The conveying means may simply take the form of horizontal rams for moving the mixing containers along the floor under say flour and water hoppers at the charging station, a dough mixer at the mixing station and a hoist at the discharging station.However, in general, it is preferred that the conveyor comprise a pair of spaced, endless, horizontal conveyor chains with spaced flights for engaging laterally-projecting members such as lugs on opposite sides of the mixing containers so that the chains extends on either side of the mixing containers, whether the mixing containers are suspended or rest on the floor.

Other preferred features of the invention are set forth in Claims 7 to 13.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of a mixing installation in accordance with the invention; Figure 2 is a part side view of a mixing container at the charging station; Figure 3 is a top view of a mixing container at the charging station; and Figure 4 is a part end view of the mixing container below (in full lines) and at (in broken lines) the mixing station.

Referring to Figure 1, the installation comprises horizontal conveying means in the form of a chain conveyor 1, a charging station 2, a mixing station 3 and a discharging station 4.

The chain conveyor has two endless, parallel chains 5 carrying flights 6, which have Ushaped depressions for receiving lugs 7 which project from either side of the mixing con tainers, which are in the form of bowls 8. As shown in Figure 2, each flight 6 is pivoted to the respective chain 5 and slides along a slide rail 9 which keeps the flight 6 in its upper, operative position. At the charging station 2, there is a pivoted slide rail 10 which, as shown in Figure 2, can be moved from an upper position (full lines) to a lower position (broken lines) to allow the flights 6 to drop from their operative position to a position in which they do not engage the lugs 7. Each pivoted slide rail 10 is connected via a pivoted lever II and a connecting rod 12 to a respective gate 13 which controls access to the conveyor (see Figure 3).When the gates 13 are open, a mixing bowl 8 can be wheeled along the floor until its lugs 7 strike the far uprights of the flights 6, after which the gates 13 can be closed in order to engage the flights 6 with the lugs 7 whilst leaving the mixing bowl 8 still supported by the floor.

At the charging station 2, there is a conventional charging apparatus and a conventional weigher, such as the weight frame of a Baker Perkins "Supertex" (RTM) mixer, a charging hood 14 and hoppers 14a for flour and water being indicated in Figure 1.

At the mixing station 3, there is a conventional batch mixer 15, such as a mixer of the Baker Perkins "Versatex" type, suspended in a gantry frame above the conveyor 1. As shown in Figure 4, each mixing bowl 8 has a second pair of lugs 16 above the first pair, and these lugs are engageable by transfer means in the form of a lifting mechanism 17 having recesses for engaging the upper lugs 16, which may be pneumatically or hydraulically operated. The lifting mechanism 17 lifts the bowl up from the conveyor 1 and into its proper position for mixing below the mixer 15, and, as shown in Figure 1, another mixing bowl 8 can pass below the first mixing bowl whilst the contents of the first mixing bowl are being mixed. The top of the mixing bowl 8 can make a hermetic seal with the mixer 15, for mixing under pressure or vacuum.

At the discharging station 4, there is a conventional hoist 18 which has arms 19 which engage the upper lugs 16, lift the mixing bowl 8 up and invert it at the top of the hoist 18, a indicated in broken lines in Figure 1.

For semi-automatic operation, various limit switches or actuating switches (not shown) can be incorporated, and these are described with reference to the operation of the installation.

The system can be operated as follows.

Although the introduction of the mixing bowls 8 is described, normally the mixing bowls 8 will remain in the installation, apart from cleaning and maintenance.

(a) With the charging hood 14 in the raised position, the gates 13 are opened by an operative and the first bowl 8 is manually fed onto the conveyor 1.

(b) The gates 13 are closed and a limit or proximity switch (not shown) recognises that the first bowl 8 is at the charging station 2.

(c) The operative presses a control button (not shown) for charging the bowl 8, and the charging and weighing operations proceed automatically after the automatic lowering of the charging hood 14.

(d) When the weigher scale (not shown) signals that the charging operation is completed, the charging hood 14 is raised automatically.

(e) The drive of the conveyor I is automatically actuated and the first bowl 8 is moved below the mixing station 3, where a limit switch (not shown) halts the conveyor.

(f) Minor ingredients such as salt, yeast and fat are fed by hand to the bowl 8.

(g) The operative presses a bowl lift button (not shown) and the lifting mechanism 17 lifts the bowl 8 into its mixing position.

(h) For production reasons, a further press button (not shown) can be provided for beginning the mixing cycle, or this can be done automatically.

(i) Steps a--d are repeated for a second mixing bowl 8.

(j) A switch (not shown) senses that no bowl is present on the conveyor 1 below the mixing station 3, and the first bowl is lowered onto the conveyor 1.

(k) When the first bowl 8 reaches the conveyor 1, it actuates the switch referred to immediately above, and the conveyor 1 is energised to convey the first bowl 8 towards the discharge station 4 and the second bowl 8 towards the mixing station 3.

(1) The conveyor 1 again stops with the second bowl 8 in a correct position below the mixing station 3, when the first bowl 8 will be in its correct position with reference to the hoist 18, the upper lugs 16 being engaged in the recesses at the ends of the hoist arms 19.

(m) The minor ingredients are added to the second bowl 8, as in (f) above, and on pressing the bowl lift button as in (g) above, the first bowl 8 is raised and discharges its contents into say a divider hopper, then being returned automatically to the conveyor 1.

(n) When the first bowl 8 reaches the conveyor 1, a further limit switch (not shown) is actuated and the conveyor 1 reverses to convey the first bowl 1 back to the charging station 2 while the second bowl 8 is in its raised position and its contents are being mixed.

(o) The empty first bowl 8 again actuates the limit or proximity switch referred to in (b) above, and the whole cycle is repeated.

As an example, the following times indicate how the operation can proceed. Charging and weighing: 1 minute 10 seconds; Mixing: 3 minutes; Discharging: I minute.

With conveying times etc, the whole cycle takes 7 minutes 50 seconds, giving the time of 3 minutes 55 seconds per bowl 8.

WHAT WE CLAIM IS: 1. A batch mixing installation comprising: a charging station for delivering ingredients to be mixed to a mixing container; a discharging station for the mixing container; conveying means for moving a mixing container along a path extending from the charging station to the discharging station and for moving a mixing container back from the discharging station to the charging station along the same path; a mixing station between the charging and discharging stations; and transfer means for transferring a mixing container from said path to a mixing position in the mixing station and for returning the mixing container to said path, the location of the mixing position and operation of the transfer means being arranged so that, when a mixing container is in the mixing position at the mixing station, said path is free for uninterrupted travel of another mixing con tainer therealong.

2. The mixing installation of Claim 1, and arranged for operation such that a cycle comprises charging a first of the mixing containers whilst a second of the mixing containers is having its contents mixed, returning the second mixing container to said path, moving the first mixing container simultaneously with the second mixing container until the second mixing container reaches the discharge station, discharging the contents of the second mixing container while in the meantime the first mixing container is transferred to the mixing station and mixing is initiated, returning the second mixing container to the charging station, and repeating for the other half cycle.

3. The mixing installation of Claim I or 2, wherein the mixing containers are open topped, and the mixing station comprises a batch mixer having a depending mixing element, the transfer means being a lifting mechanism for lifting successive mixing containers up into the mixing position around the mixing element.

4. The mixing installation of Claim 3, for mixing bakery dough and wherein the charging station includes an elevated flour hopper and water hopper mounted on a weighframe, the batch mixer is a dough mixer, and the discharging station is for tipping succes sive mixing containers for discharging their contents and comprises a hoist for raising the mixing containers above floor level and for returning the empty mixing containers back to the conveying means.

5. The mixing installation of any of the preceding Claims, when the conveying means comprises a pair of spaced, endless, horizontal conveyor chains with spaced flights for engaging laterally-projecting members on opposite sides of the mixing containers so that the chains extend on either side of the mixing containers.

6. The mixing installation of any one of the preceding Claims, and being arranged for wheeled mixing containers which can be pushed along the floor, the conveying means being for conveying and guiding the mixing containers while the mixing containers continue to be supported by the floor.

7. The mixing installation of any one of the preceding Claims, and being arranged for wheeled mixing containers which can be pushed along the floor, the conveying means being arranged such that mixing containers can be removed therefrom or introduced thereto by being wheeled by hand along the floor.

8. The mixing installation of any one of the preceding Claims, when the mixing containers can be removed from or introduced to the conveying means at the charging station.

9. The mixing installation of any one of the preceding Claims, when the mixing containers can be removed from or introduced to the conveying means, and wherein the conveying means includes flights for engaging respective mixing containers to convey them, which flights can be rendered inoperative to enable a mixing container to be removed from or introduced to the conveying means.

10. The mixing installation of Claim 9, wherein the flights are actuated by a gate which when closed prevents access of a mixing container to the conveying means and maintains the flights in the engaged position, and when open, renders the respective flights inoperative.

I 1. The mixing installation of any one of the preceding Claims, wherein the mixing container has laterally projecting members for engagement by flights on the conveying means, and the flights have U-shaped depressions for receiving the respective members.

12. The mixing installation according to Claim 7 Claim 9 or 10, when the flights are movably mounted on the conveying means such that they can move downwards with respect to the conveying means to allow a mixing container to be removed from or introduced to the conveying means without needing to raise the mixing container, and can be moved upwards into a position in which the flights engage the mixing container.

13. The mixing installation of any one of the preceding Claims, when each mixing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Mixing: 3 minutes; Discharging: I minute. With conveying times etc, the whole cycle takes 7 minutes 50 seconds, giving the time of 3 minutes 55 seconds per bowl 8. WHAT WE CLAIM IS:

1. A batch mixing installation comprising: a charging station for delivering ingredients to be mixed to a mixing container; a discharging station for the mixing container; conveying means for moving a mixing container along a path extending from the charging station to the discharging station and for moving a mixing container back from the discharging station to the charging station along the same path; a mixing station between the charging and discharging stations; and transfer means for transferring a mixing container from said path to a mixing position in the mixing station and for returning the mixing container to said path, the location of the mixing position and operation of the transfer means being arranged so that, when a mixing container is in the mixing position at the mixing station, said path is free for uninterrupted travel of another mixing con tainer therealong.

container has two laterally-projecting members on each side, one above the other, the lower pair of members being for engaging flights of the conveying means for conveying the mixing containers, and the upper pair of members being for engagement by the transfer means for moving the mixing containers to the mixing station.

14. A method of batch mixing using the installation of any one of the preceding claims, wherein one mixing container is emptied at the discharge station, is conveyed to the charging station and is filled, while another mixing container has its contents mixed.

15. A batch mixing installation, substantially as herein described with reference to, and as shown in, the accompanying drawings.

16. A method of batch mixing, substantially as herein described with reference to the accompanying drawings.