Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2/00—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor
  • A61L2/02—Methods or apparatus for disinfecting or sterilising materials or objects other than foodstuffs or contact lenses; Accessories therefor using physical phenomena
  • A61L2/04—Heat
  • A61L2/06—Hot gas
  • A61L2/07—Steam
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23K—FODDER
  • A23K30/00—Processes specially adapted for preservation of materials in order to produce animal feeding-stuffs
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
  • A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
  • A23L3/16—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating loose unpacked materials
  • A23L3/18—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating loose unpacked materials while they are progressively transported through the apparatus
  • A23L3/185—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating loose unpacked materials while they are progressively transported through the apparatus in solid state
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
  • A23L3/00—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs
  • A23L3/16—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating loose unpacked materials
  • A23L3/18—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating loose unpacked materials while they are progressively transported through the apparatus
  • A23L3/22—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating loose unpacked materials while they are progressively transported through the apparatus with transport through tubes
  • A23L3/225—Preservation of foods or foodstuffs, in general, e.g. pasteurising, sterilising, specially adapted for foods or foodstuffs by heating loose unpacked materials while they are progressively transported through the apparatus with transport through tubes in solid state
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23N—MACHINES OR APPARATUS FOR TREATING HARVESTED FRUIT, VEGETABLES OR FLOWER BULBS IN BULK, NOT OTHERWISE PROVIDED FOR; PEELING VEGETABLES OR FRUIT IN BULK; APPARATUS FOR PREPARING ANIMAL FEEDING- STUFFS
  • A23N17/00—Apparatus specially adapted for preparing animal feeding-stuffs
  • A23N17/004—Apparatus specially adapted for preparing animal feeding-stuffs for treating by application of heat, e.g. by means of potato cookers

Definitions

• the invention relates to a method of sterilising granulate and particulate material, wherein steam is added to the material to heat it to sterilisation temperature and the material is maintained at this temperature for a necessary residence time.
• the invention has been especially developed in connection with the need to render harmless salmonella bacteria in animal feed.
• Salmonella has become a growing problem which has resulted in long-term sick leave and at times even a fatal outcome.
• the problem has now grown to such proportions that the EU has directed that all animal feed is to be heated to a minimum of 80°C. From research into the problem complex, it is known that heating to a temperature of 80°C without a residence time will not render the salmonella bacteria harmless, as this requires a combination of temperature, moisture and residence time.
• Eggs are a major source of salmonella infections. The problem has now become so great that in many places on the continent it is not possible to buy soft-boiled eggs or fried eggs as the heat treatment of the yoke is inadequate. Similarly, meat may be infected with salmonella and the consumption thereof may have a disabling result.
• Today's equipment in animal feed factories is not capable of handling the required sterilisation, i.e., the directive that all feed must be heated to a minimum temperature of 80°C and kept at this temperature for a sufficient period of time.
• a short residence time requires high temperature and adequate moisture.
• the temperature typically may be 120°C.
• the costs of generating this temperature are very high, both in terms of running costs and in the purchasing of equipment.
• the high temperature damages a part of the grain (feed), which becomes difficult to digest. Other parts of the grain become easier to digest, but this may again be achieved by using a lower temperature for a longer time without the damaging side-effects that the high temperature causes.
• a method is proposed as mentioned above, characterised in that the granulate and particulate material is agitated to a fluid state whilst being heated by a supply of steam, and that after agitation and heating the material is passed directly into a residence vessel from where the material is discharged after the desired residence time.
• One particular advantage of the invention is that the method can be carried out in connection with already existing equipment, modified in a very simple manner (procurement of a residence vessel and insulation of existing mixing plant).
• the material is gravity- transferred directly to the residence vessel.
• the invention also relates to a means in a mixing apparatus, which mixing apparatus includes a housing, an intake opening in the housing, a discharge opening in the housing and agitator means provided inside the housing for fluidising a granulate or particulate material.
• a mixing apparatus of this kind is a common piece of equipment in feed factories, where a typical diagram would be a weighing system, a mixing apparatus, a receptacle, an elevator to a silo, a conditioning system and a pellet press.
• the housing should have an inlet for the supply of steam to the material in the housing, and that the housing discharge opening should be attached to a vessel for receiving material from the housing through the discharge opening.
• the said material receiving vessel can be used as a residence vessel in connection with the sterilisation of the feed by means of heating to a sterilisation temperature by supplying steam to the mixing apparatus, where the granulate or particulate material is agitated to a fluid state in connection with the mixing that takes place therein.
• the vessel is very simply arranged under the mixing apparatus.
• the invention also means that silos before cascade mixers and pellet presses can be dispensed with.
• the cascade mixer on the pellet press may be dispensed with, and thus overall in terms of investments the sum required is lower than today's investment, and in addition the requisite protection against salmonella is obtained. If such protection is to be obtained by using the plants common in feed factories today, a major investment must be made in expanders or extruders in order to elevate the temperature sufficiently, because a prolonged residence time cannot be used.
• the running costs would be very high in such a case.
• the invention will help considerably to reduce investments. Since, in today's plants the product is already heated, the energy used for this will be channelled into the mixing apparatus/conditioning and will involve only slightly higher costs related to a somewhat higher temperature, but considerably lower costs for heating than, e.g., expanders which supposedly raise the temperature of the product to 120°C, which in turn requires higher costs in order to bring the temperature back down to ambient temperature.
• the vessel advantageously has a discharge device in the bottom region thereof.
• the discharge device may be a horizontal feed screw and may to advantage be progressive, in order thereby to maintain a desired horizontal free surface for the material in the residence vessel.
• both the housing and the vessel are thermally insulated, or have external heating or a combination of both.
• the steam inlets are advantageously located according to the invention in a lower portion of the housing.
• Agitator means may include two interacting horizontal paddle rotors.
• the volume of the vessel is larger than that of the housing. It is particularly advantageous if the volume of the vessel is at least 1.7 times that of the housing.
• Fig. 1 is a vertical section through a means according to the invention; and Fig. 2 is a vertical section 90° to the section in Fig. 1.
• the drawings show a mixing apparatus 1 having two horizontal paddle units 2, 3 in the apparatus housing 4.
• the mixing apparatus 1 may, for example, be of the general type that is described in EP 219471.
• a mixing apparatus of this kind has two horizontal motor-powered shafts provided with blades or paddles which beat the granulate or particulate material with which the housing 4 is filled, and fluidise the product during a mixing process.
• the mixing apparatus 1 has an intake opening 5 and two discharge openings 6, 7 in the bottom region.
• the discharge openings 6, 7 can be opened and closed by means of sluices 8, 9 which in Fig. 1 are indicated with broken lines and are swung down into an open discharge position so that the product poured into the housing 4 through the intake opening 5 can, after mixing, be discharged through the discharge openings 6, 7.
• a residence vessel 10 In direct connection with the lower part of the mixing apparatus around the discharge openings 6, 7 there is provided a residence vessel 10 into which the product processed in the mixing apparatus 1 can fall straight down, through the opened discharge openings
• the residence vessel 10 has a funnel-shaped lower region wherein at the bottom there is provided a progressive feed screw 11 which conveys the product out of the residence vessel 10 through an opening 12.
• the mixing apparatus 1 is provided with a plurality of steam nozzles 13 through which steam can be fed into the mixing apparatus. These steam nozzles are arranged advantageously in the lower region of the mixing apparatus beneath the agitators 2, 3.
• the plant in the drawings functions in the following manner.
• the granulate or particulate material (not shown) is fed into the mixing apparatus 1, 4 through the intake opening 5.
• the sluices 8, 9 are closed.
• the agitators 2, 3 are used to provide an agitation of the filled material in order to mix it in a commonly known manner.
• Steam is introduced through the nozzles 13 to heat the fluidised material.
• the introduction of steam also means that desired moisture is added to the material in the mixing apparatus.
• the agitators 2, 3 are stopped and the discharge openings 6, 7 are opened.
• the material in the mixing apparatus will then fall straight down into the vessel 10.
• the sluices 8, 9 are closed.
• a fresh quantity of product can then be poured into the mixing apparatus for mixing and sterilisation.
• the product that has been transferred to the vessel 10 will remain in the vessel 10 for a period of time necessary to obtain of the requisite sterilisation.
• the product is conveyed out though the opening 12 by means of feed screws 11 and preferably concurrently with the product material which comes from the mixing apparatus.
• the plant may to advantage be insulated, as indicated by means of the reference numeral 14, and optionally external heating (not shown) may also be provided, in addition to or instead of insulation.
• the heating may, for example, take place electrically or by using a steam loop.
• the invention provides the advantage that it is possible to use a mixing apparatus which is already an integrated part of a feed production and which exists in several different types. The only departure is that the apparatus should be insulated and partly heated to avoid cold surfaces which may cause the salmonella bacteria to survive. Similarly, a vessel 10 must be provided where the product can be kept for a minimum of three minutes, so that the necessary residence time in the system is obtained. In the plant according to the invention, it is possible in a simple manner to obtain a desired temperature, residence time and moisture in order to satisfy the requirements made with respect to a sterilisation of the feed product.
• the mixing apparatus may be one of many different types. The requirement is that it must be capable of fluidising the product, so that a very efficient mixing of the steam into the feed or product is achieved, in order thereby to obtain the sufficient, uniform temperature increase in the product.
• the steam may be overheated to better balance the quantity of moisture which is added to the product.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Polymers & Plastics (AREA)
• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Nutrition Science (AREA)
• Animal Behavior & Ethology (AREA)
• Epidemiology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Animal Husbandry (AREA)
• Zoology (AREA)
• Apparatuses For Bulk Treatment Of Fruits And Vegetables And Apparatuses For Preparing Feeds (AREA)
• Food Preservation Except Freezing, Refrigeration, And Drying (AREA)
• Apparatus For Disinfection Or Sterilisation (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19900504

Family Applications (1)

Country Status (3)

Cited By (8)

Citations (6)

• 1997
  • 1997-03-17 NO NO971221A patent/NO971221L/no unknown
• 1998
  • 1998-03-13 AU AU64252/98A patent/AU6425298A/en not_active Abandoned
  • 1998-03-13 WO PCT/NO1998/000083 patent/WO1998043682A1/en active Application Filing

Patent Citations (6)

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