WO2001055654A1

WO2001055654A1 - Spiral conveyor cooling apparatus

Info

Publication number: WO2001055654A1
Application number: PCT/SE2001/000120
Authority: WO
Inventors: Gregory L. Ochs
Original assignee: Frigoscandia Equipment Ab
Priority date: 2000-01-25
Filing date: 2001-01-24
Publication date: 2001-08-02
Also published as: AU2001229010A1

Abstract

An improved apparatus for chilling food products using water with a spiral conveyor. Structural support members for the conveyor convey and distribute the chilled water to spray nozzles disposed above the conveyor tiers. A plurality of hollow vertical columns are provided adjacent and at spaced intervals around the spiral conveyor. A plurality of hollow arms protrude generally horizontally from each column and across the spiral conveyor. Each arm is disposed beneath one of the spiral loops and supports a portion of a plurality of rails helically disposed between the spiral conveyor and the arms. The rails support the conveyor, the arms support the rails and each arm is in fluid communication with the column to which it is attached. Chilled fluid is conducted from a source of chilled fluid through the columns and into the hollow arms which arms have a plurality of apertures, preferably with nozzles, for dispensing the chilled liquid onto packaged materials on the conveyor.

Description

SPIRAL CONVEYOR COOLING APPARATUS

BACKGROUND OF THE INVENTION

1. Field of the Invention.

The present invention relates, generally, to cooling apparatus for food products. More particularly, the invention relates to cooling apparatus using a continuous spiral

conveyor system.

2. Description of the Prior Art.

The state of the art includes various devices and methods for chilling and freezing materials, particularly package food products. Prior art devices and methods are believed to have significant limitations and shortcomings.

Batch tumblers tumble a batch of product inside the cylinder. The cylinder may

have a cooling jacket on its outside, or ice may be mixed with the product inside.

Continuous tumblers use a long cylinder with an auger on the inside. The product is introduced to the lower end and augered up to the other end while chilled water is

introduced at the top of the tube and flows down through the product in a counter flow

manner. Both of these types of coolers risk damaging the product due to the tumbling

motion.

Multi-pass flow tanks use a series of shallow tanks filled with refrigerated water

into which the product is deposited. A metal conveyor belt drags along the bottom of the

tank to move the product along, then out of the tanlc and into a subsequent tank. Packaged

products submerged in water typically have neutral buoyancy, are subject to hydrodynamic

forces and tend to cluster as they move from one end of the tank to the other. Conveyor

efficiency is affected and water circulation about the product is inhibited resulting in inefficient heat removal. An improvement of these systems uses baskets on a continuous

loop conveyor to hold the product.

For chilling packaged food products on a moving conveyor belt, a refrigerated coil

is located above the moving belt which may be single pass or multipass. Water cascades

down through the coil and is chilled before falling onto the moving product and tlirough the

open belt into a holding tank where it is recirculated back to the cooling coil. With this system, only the top tier of a multipass system sees the coldest water. Lower tiers use water

that has been warmed by contact with upper levels, thus these linear systems require substantial length to achieve adequate production capacities.

A well-known apparatus uses an endless belt traveling in a helical or spiral path around a central drum to convey food products through a zone where a coolant medium chills and freezes them. One spiral cooler uses vertical columns adjacent the spiral

conveyor to dispense chilled water horizontally onto the conveyor from nozzles located in

the side of the column. Because the nozzles are located to the sides of the conveyor belt,

complete spray coverage of the belt may be difficult.

Spiral conveyors are also used with different cooling apparatus to freeze material on

the conveyor. U.S. patents 5,452,588 to Onodera and 5,170,631 to Lang et al. disclose

typical spiral-type freezing apparatus. Mechanical refrigeration is often used to chill air to a

temperature ranging from -20°C to -40°C, then fans and ducts direct the chilled air onto the

food products traveling along the spiral conveyor as disclosed in the Onodera patent. Other

means for freezing food products direct cryogenic gas or liquid onto the food products

traveling on the conveyor. The cryogenic material is conveyed tlirough separate feed lines

distributed among the conveyor tiers as disclosed in the Lang et al. patent. While these cooling techniques work well for freezing food products, they are not well suited for

chilling products to a temperature around 5°C. Chilled air has relatively low thermal mass,

therefore requiring a great deal of convective activity, and hence large fans, to effectively

cool food products. Furthermore, the use of very cold air or cryogenic material may

inadvertently freeze corners of pouches containing liquid to be chilled, thereby damaging

the pouches. Though a system designed for delivering cryogenic liquid or gas, such as

disclosed in Lang et al. could be used for delivering water, the volume of water required

may be significantly greater than can be efficiently supplied by the cryogenic apparatus.

Also, the system for delivering cryogenic materials uses plumbing that is separate and distinct from the conveyor structure, thereby adding complexity to the apparatus.

The present invention provides an improved apparatus for chilling food products

which overcomes the limitations and shortcomings of the prior art by efficiently using

chilled water as the cooling medium with a spiral conveyor, and by using the structural support members for the conveyor to convey and distribute the chilled water to spray nozzles disposed above the conveyor tiers.

BRIEF SUMMARY OF THE INVENTION

The present invention adapts a spiral conveyor apparatus for use with chilled liquid

to cool food products. The apparatus is most useful for food products, such as soups and

sauces, that are packaged in sealed containers, such as plastic bags, pouches, tubs or cups entering at a temperature above 100°F and with required outfeed temperatures not lower

than 40°F .

The structural support members for the conveyor are used to distribute chilled

liquid, such as water or glycol, to a plurality of nozzles disposed above each loop of the

conveyor. A plurality of hollow vertical columns are provided adjacent the spiral conveyor

spaced at intervals, preferably around and outside of the spiral conveyor. A plurality of

hollow arms protrude generally horizontally from each column and across the spiral

conveyor. Each arm is disposed beneath one of the loops and supports a portion of a

plurality of rails helically disposed between the spiral conveyor and the arms. The rails

support the conveyor, the arms support the rails.

Each arm is in fluid communication with the column to which it is attached. Chilled fluid is conducted from a source of chilled fluid through the columns and hollow arms. The

arms have a plurality of apertures for dispensing the chilled liquid onto packaged materials

on the conveyor. Preferably the apertures are adapted to receive spray nozzles which

preferably direct the chilled fluid in a conical pattern so that water makes direct contact

with both the top and bottom surfaces of the food product.

The features, benefits and objects of this invention will become clear to those

skilled in the art by reference to the following description, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a portion of a spiral chilling apparatus of the present

invention showing a portion of the conveyor and associated support structure;

Fig. 2 is a cross sectional view of the support structure for conveyor tiers taken

along line 2-2 of Fig. 1; and

Fig. 3 is a cross sectional view of an arm and nozzles taken along line 3-3 of Fig. 1

DETAILED DESCRIPTION

Apparatus to cool and freeze food on an endless conveyor that travels in a spiral

path inside of an insulated container is well known in the art. Food products are deposited

on a portion of the conveyor which protrudes from the insulated container at one location.

The food products are carried around a spiral path and exit the insulated container at

another location where they are removed from the conveyor. Inside the container, various

means such as mechanical refrigeration and cryogenic liquids and gases, are typically used

along the conveyor's spiral path to cool and freeze the food products. The present

invention adapts a spiral conveyor apparatus for use with chilled water to cool food

products rather than freeze them. The apparatus is most useful for food products, such as

soups and sauces, tliat are packaged in sealed containers, such as plastic bags, pouches, tubs or cups entering at a temperature above 100°F and with required outfeed temperatures not

lower than 40°F .

Refenϊng to Figs. 1 and 2, the chilling apparatus 10 includes an endless conveyor

belt 12 arranged to move in a helical spiral path around a central drum 14 which provides

the conveyor drive. The conveyor belt makes a series of the belt tiers 12a, 12b, 12c, etc.,

with each belt tier being separated by approximately 4 to 6 inches. The spiraling portion of

conveyor 12 is supported and guided by rails 16 which are helically disposed under each

belt tier 12a, 12b, 12c, etc. Preferably there are two parallel rails 16, one near the inner edge of the conveyor and one near the outer edge, although additional rails may be used if ■

needed to support the conveyor 12. Conveyor rails 16 are supported at each belt tier at

circumferential intervals around the spiral by a plurality of generally horizontal arms 18

disposed beneath the rails and connected to a plurality of vertical columns 20, which are

disposed adjacent the outside periphery of the spiral conveyor. Arms 18 at a particular

circumferential location of the spiral preferably align vertically and are cantilevered from an

associated vertical column 20. Arms 18 extend generally radially inwardly from columns

20 relative to the spiral and span the rails 16.

Arms 18 and columns 20 are hollow, preferably made of square tubing, and are in

fluid communication with each other. Each column 20 acts as a water distribution header

with chilled water being supplied through each inlet pipe 22, preferably located near the top

of each column 20. The chilled water is distributed through each header column 20, as

indicated by the arrows, and into the associated arms 18, the support structure thus

providing the water distribution system. Additional arms 18a for distributing chilled water

are preferably provided above the top conveyor tier 12a, although they do not support a conveyor tier. Each arm 18 has a plurality of nozzles 24 constructed and arranged to

dispense the chilled water uniformly onto the food products on conveyor belt tiers 12a, 12b,

12c, etc.

Referring also to Fig. 3, nozzles 24 are preferably removable plastic spray nozzles

disposed on opposite sides 26 and 28 of arm 18. with this arrangement, chilled water is

sprayed uniformly, generally in a horizontal cone pattern, along lines 30 in both directions

from arm 18 so as to be directed upwardly into a conveyor tier above and downwardly onto

a conveyor tier below the arm 18. This spray pattern provides direct water contact with

both the top and bottom surfaces of the food product. Nozzles are arranged in a pattern that

ensures complete coverage over the belt surfaces and minimizes overspray. Each nozzle preferably dispenses 1-1.3 gallons per minute of water, and the chilling apparatus typically

has about 500 nozzles.

Referring to Fig. 1, each column 20 preferably has a plurality of nozzles 32, similar

to nozzles 24, disposed just below each arm 18, constructed and arranged to spray chilled

water generally horizontally and downwardly onto an adjacent conveyor tier 12a, 12b, 12c,

etc. Columns 20 are disposed on the outside of the spiral and nozzles 32 dispense water

inwardly from the outside of the conveyor 12.

Conveyor belt 12 is of open mesh construction which allows water dispensed on the

upper tiers to cascade downward to cool product on lower tiers, resulting in very efficient use of chilled water. Water may be recycled through a floor sump system in a known

manner and pumped back through a chilling system, filters, and conduits to inlet pipes 22

on columns 20. To achieve lower temperatures, glycol may be used in place of water. Delivering coolant through the support structure of the spiral conveyor provides efficient use of materials and simplifies construction and maintenance of the cooling apparatus by eliminating conventional headers and plumbing associated with conventional

coolant delivery systems that are separate from the conveyor's structural elements. The

conveyor system itself thus acts as a cooler for the product. The arrangement of hollow

conduit/columns and support arms allows the nozzle to be mounted above the conveyor

surface at each tier so as to obtain even distribution of cooling water on the conveyor

surface. Since the nozzle spray is a horizontal cone pattern, the cooling water comes into direct contact with both the top and bottom surfaces of the product.

The descriptions above and the accompanying drawings should be interpreted in the illustrative and not the limited sense. While the invention has been disclosed in connection

with the preferred embodiment or embodiments thereof, it should be understood that there

may be other embodiments which fall within the scope of the invention as defined by the

following claims.

Claims

What is claimed is:

1. Product cooling apparatus comprising;

a spiral product conveyor system for moving product to be cooled, a hollow liquid coolant dispensing support frame connected to support said

conveyor system,

spray nozzles on said frame for directing cooling liquid onto the surfaces of said conveyor, and

a liquid coolant supply source for circulating pressurized liquid coolant through said support frame.

2. The apparatus of claim 1 wherein; said spiral conveyor includes superimposed loops forming multiple conveyor tiers, said spiral nozzles being located between adjacent tiers and mounted for spraying

liquid coolant onto the top and bottom surfaces of successive tiers.

3. The apparatus of claim 2 wherein said spray nozzles are configured to spray liquid coolant in a conical pattern.

4. The apparatus of claim 3 wherein said nozzles are mounted to spray liquid

coolant in both longitudinal directions relative to the path of the moving conveyor.

5. Apparatus for chilling packaged materials, comprising;

a spiral conveyor having a plurality of superimposed loops,

a plurality of hollow vertical columns spaced about the spiral conveyor, each

column conducting chilled fluid therein,

each column having a plurality of generally horizontal hollow arms, each arm

disposed beneath and supporting a portion of one of the loops, each arm being in fluid

communication with the column to which it is attached, and

a plurality of apertures in said arms for dispensing the chilled fluid,

whereby chilled fluid is conducted through said columns and said arms and through' said apertures onto packaged materials carried on the conveyor.

6. The apparatus of claim 5, wherein said apertures are adapted to mount spray

nozzles, said apparatus further comprising;

a plurality of nozzles, each nozzle being mounted by one of the apertures, each

nozzle being constructed and arranged to spray the chilled fluid onto a portion of a loop of

the spiral conveyor.

7. The apparatus of claim 5 further comprising a plurality of rails helically

disposed between the spiral conveyor and supported on the arms, said rails being connected to support the conveyor.

8. The apparatus of claim 5 wherein the arms extend generally radially across the spiral conveyor.

9. The apparatus of claim 8 wherein the columns are disposed outside of the spiral conveyor, and the arms extend inwardly therefrom.

10. The apparatus of claim 6 wherein the nozzles are constructed and arranged

to spray the chilled fluid in a conical pattern.

11. The apparatus of claim 4 wherein the chilled fluid is water.

12. The apparatus of claim 4 wherein the chilled fluid is glycol.

13. An apparatus for chilling packaged materials, comprising;

a spiral conveyor having a plurality of superimposed loops,

a plurality of hollow vertical columns adjacent the spiral conveyor spaced at

intervals around the conveyor, each column conducting chilled fluid therein, each column having a plurality of hollow arms protruding generally horizontally

therefrom across the spiral conveyor with each arm being disposed beneath one of the

loops, each arm being in fluid communication with the column to which it is attached and

having a plurality of apertures for receiving nozzles,

a plurality of rails helically disposed between the spiral conveyor and supported on

the arms, said rails being connected to support the conveyor, and a plurality of nozzles, each nozzle being received by one of the apertures in the hollow arms and being constructed and arranged to spray the chilled fluid onto a portion of a loop of the spiral conveyor.

14. An apparatus for chilling packaged materials, comprising; a spiral conveyor having a plurality of superimposed loops, a plurality of hollow vertical columns adjacent the spiral conveyor spaced at intervals around and outside of the spiral conveyor, each column conducting chilled fluid

therein, each column having a plurality of hollow arms protruding generally horizontally radially inward therefrom across the spiral conveyor with each arm being disposed beneath one of the loops, each arm being in fluid communication with the column to which it is

attached and having a plurality of apertures for receiving nozzles, a plurality of rails helically disposed between the spiral conveyor and supported on the arms, said rails being connected to support the conveyor, and a plurality of nozzles, each nozzle being received by one of the apertures in the

hollow arms and being constructed and arranged to spray the chilled fluid onto a portion of a loop of the spiral conveyor.