US 3420156 A
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Description (OCR text may contain errors)
G. ANDERS Jan. 7. 1969 DISCHARGE DEVICE FOR A VACUUM COOKER USED TO COOK A SUGAR MASS Sheet Filed May 11, 1967 INVENTOR: GERHA RD Auzmes Annexe-v:
Jan. 7, 1969 (5. ANDERS 3,420,156
DISCHARGE DEVICE FOR A VACUUM COOKER USED TO COOK A SUGAR MASS 7 Filed May 11, 1967 Sheet 2 of z INVENTOR: GERHA no Aubsks ATTORNEYS United States Patent 3,420,156 DISCHARGE DEVICE FOR A VACUUM COOKER USED TO COOK A SUGAR MASS Gerhard Anders, Viersen, Germany, assignor to Hamac- Hanseila Gesellschaft mit heschrankter Haftung, a corporation of Germany Filed May 11, 1967, Ser. No. 637,720 Claims priority, application Germany, May 12, 1966,
H 59,372 U.S. c1. 99-234 2 Claims rm. c1. A231 1/00 ABSTRACT OF THE DISCLOSURE The present invention relates to a continuously operating discharge device for a vacuum cooker used to cook a sugar mass in the manufacture of hard candy.
In order to prepare hard candy, having good keeping qualities, from a sugar mass, the water content must be very low. For example, the water content of hard caramels must be between 1% and 2%. In order to obtain this low water content economically, it is known to place the sugar mass, particulaly the sugar/ glucose syrup solution, under vacuum after it is cooked. It has been found that devices which operate on batches of the sugar mass have numerous disadvantages. In particular, the time during which the vacuum acts on the mass is not uniform throughout, with the result that the water content varies throughout the mass.
German Patent No. 820,843 shows a device in which the removal of water from sugar masses takes place in a vacuum chamber. However, this device is intended for a sugar mass which crystallizes, producing a slurry of crystals. Removal of the slurry of crystals from the vacuum container is effected continuously by means of a gear pump. This device is unsuitable for treating a sugar mass of the type mentioned above, whose crystallization is to be prevented, since the use of a gear pump for removal of the sugar mass produces strong mechanical stresses within the sugar mass which lead to crystallization.
French Patent No. 1,366,806 described another withdrawal device employing a heated gear pump for sugar masses which are treated in a slight vacuum. In this device there is also the danger of the crystallization of the sugar mass. Furthermore the sugar mass easily sticks to the teeth of the gear pump, since a sugar mass as is known adheres to metal parts which are heated to the boiling point of the mass or above.
An object of the present invention is to provide a device for the continuous removal of a sugar mass treated under high vacuum in such a manner as to avoid any formation of crystals.
For this purpose, the invention proposes a discharge device of the aforementioned type which is characterized by the fact that at least one withdrawal slot at the bottom of the vacuum vessel is defined, at least on one side, by a heated discharged roller which rotates in the direction of discharge.
It has been found that a sugar mass can be discharged ice through a slot by smooth or substantially smooth rollers of the aforementioned type without crsytallization of the sugar mass occurring as a result of the mechanical stresses. By preferably heating the discharge roll or rolls, to or above the boiling point of the sugar mass, the sugar mass is caused to adhere even to a completely smooth discharge roll and is dependably discharged through the gap. Scrapers for cleaning the discharge rolls are provided within the discharge space adjoining the discharge slot. The slot width and the speed of rotation of the discharge roll or rolls must be so adapted to each other, with due consideration to the viscosity of the sugar mass, that the sugar mass cannot be forced back into the vacuum vessel by the atmospheric air pressure within the discharge space, but is definitely discharged by the rotation of the discharge roll or rolls.
In the case of vacuum vessels of small output, use of one discharge roller is sufiicient. In accordance with another form of the invention, two discharge rolls can be provided arranged alongside each other and contacting each other along a line on the surface of each roll, said rolls having, in the region of contact, an upwardly directed circumferential movement and serving alternately as strippers for each other. A discharge slot can be provided in the space between the peripheral part of each discharge roll facing away from the contact region and the wall of the vacuum vessel.
In accordance with a modified embodiment, the invention proposes that there be provided two discharge rolls arranged alongside each other and separated by a discharge slot, the rolls having a downwardly directed circumferential movement at the region of the slot. A sealing strip is arranged in contact with each roll in front of the entrance into the region of the slot, and a scraper contacts the surface of each roll after passage through the region of the slot.
It has been found advisable to provide the walls with heating means in the discharge region of the vacuum vessel.
In order that the mechanical stress on the sugar mass is as slight as possible, a drive is provided for each discharge roll such that the speeds of rotation of the rolls are precisely the same. In the removal region between the discharge slot and the stripper or strippers a region of turbulence is formed. Here the invention proposes providing injection nozzles through which solid or liquid additives, e.g., essential oils or color additives, can be introduced into the sugar mass.
Details of the invention will be noted from the following description of a few preferred embodiments, read with reference to the accompanying drawings, in which:
FIG. 1 is a vertical cross-section through a first embodiment of the invention;
FIG. 2 is a section along the line II--II of FIG. 1;
FIG. 3 is a vertical cross-section through a modified embodiment of the invention; and
FIG. 4 is a vertical cross-section through a third embodiment of the invention.
At the bottom of a vacuum vessel 12 (FIGS. 1 and 2), which may be a cooking vessel, or a vessel into which the sugar mass is introduced after cooking, there are provided, alongside of each other, two withdrawal rolls 1. The rolls contact or almost contact each other along a line 4 on the surface of each, and the direction of rotation of the rollers is such that they move upwardly in the vicinity of the line 4. Between the circumstance of each roll 1 and the inner wall 2 of the discharge end 13 of the vacuum vessel 12, a withdrawn slot 3 is established. Within the discharge region 7, 8 behind the withdrawal slot 3, injection nozzles for liquid or solid additives are provided. The discharge end 13 has an outlet opening 5 closed by a cover 6 which can 'be lifted off in a suitable manner. Below the cover 6 there may be provided a conveyor belt 9. However, a distributor pipe for molds can also be provided instead. The discharge end 13 has hollow walls 14 through which a heating agent can be conducted by suitable connecting pipes in the manner indicated.
The withdrawal rolls 1 are mounted on drive shafts 15 which are driven in synchronism so that the speeds of rotation of the withdrawal rolls 1 are equal. Each withdrawal roll 1 has a hollow shaft 15 through which a heating agent can be introduced into the hollow withdrawal rolls 1. The feeding of the heating agent is effected in each case through the pipes 16 which extend through the hollow shafts 15 into the hollow withdrawal rolls 1 while the heating agent is led away via the connections 17 of the hollow shaft 15. The supporting and sealing of these parts is efiected in known manner and therefore is not described in detail.
The manner of operation of this device is as follows: The sugar mass passes continuously through the vacuum vessel 12 where a removal of water takes place. At the bottom of the vacuum vessel the heated Withdrawal rolls I carry along with them a uniformly thick layer of the sugar mass and remove it through the withdrawal slot 3. As already stated, the speed of rotation of the withdrawal rolls and the Width of the withdrawal slot are so related to each other that the atmospheric air pressure in the discharge space cannot force the sugar mass back into the vacuum vessel. The withdrawal rolls are preferably heated to or above the boiling point of the sugar mass. Along the line 4 the withdrawal rolls 1 practically contact each other so that the layer of sugar mass there is forced 011 and the withdrawal rolls thus act as strippers with respect to each other.
In the discharge space, a region of strong turbulence 7, 8 is formed so that it is possible to inject at that point additional substances which intimately mix with the sugar mass. The closure cover 6 is normally open during operation. Upon starting, however, this cover is closed so that the atmospheric air pressure cannot penetrate into the vacuum vessel 12. After the sugar mass has closed the slots 3, due to the operation of the rolls, 1, the closure cover 6 can remain open continuously.
A modified embodiment of the invention, shown in FIG. 3, also has two withdrawal rolls 1 which define between them a withdrawal slot 10, the sugar mass being discharged through this withdrawal slot. At the level at which the sugar is introduced into the region of the slot, a sealing strip 18 extends along a line on the surface of each withdrawal roll. Scrapers 19 remove the sugar mass from the rolls after they pass through the region of the slot. The manner of operation of this embodiment of the invention corresponds to the embodiment described above so that no description of it is thought necessary.
FIG. 4 shows a withdrawal device for vacuum vessels having a small output, only one withdrawal roll 1 being used. In this case a withdrawal slot 3 is provided between the withdrawal roll and the inner wall 2 of the withdrawal part 13. Furthermore the withdrawal roll 1 is provided with a sealing strip 18 and a scraper 19. The manner of operation of this device also corresponds to the operation already described above.
What is claimed is:
1. In a vacuum vessel for a sugar mass in the manufacture of hard candy, the sugar mass being discharged through slots near the bottom of the vessel, a withdrawal device comprising two side-by-side rolls in contact with each other along a line on the surface of each roll, one of said slots being defined between a portion of each roll remote from the other and an opposed portion of the vessel wall, and means for rotating said rolls in opposite directions such that the roll portions in contact move upwardly, said rolls thereby serving as strippers for each other, and the surface of each roll adjacent to its respective slot moves in the direction of withdrawal of the mass from the slot.
2. In a vacuum vessel, the arrangement defined in claim 1 including injection nozzles for introducing additives into the turbulence region between said slot and said scraper.
References Cited UNITED STATES PATENTS 968,110 8/1910 Barbieri 107-54 1,737,447 11/1929 Baker et al 99-134 2,238,164 4/1941 Edwards 107-54 2,622,855 12/1952 Kulp et a1 259-64 2,811,117 10/1957 Monaco 107-54 XR 3,009,427 11/1961 Bell 99-134 XR 3,149,056 9/1964 Longstreth, et al. 3,156,195 11/1964 Evanson et a1 107-54 3,294,038 12/1966 Rossi 107-54 XR WALTER A. SCHEEL, Primary Examiner. JOHN M. NEARY, Assistant Examiner.
US. Cl. X.R. 107-54; 159-11