GB2249706A

GB2249706A - Conditioner for animal feed

Info

Publication number: GB2249706A
Application number: GB9119236A
Authority: GB
Inventors: Richard V Lucas
Original assignee: Scott Equipment Co Inc
Current assignee: Scott Equipment Co Inc
Priority date: 1990-11-07
Filing date: 1991-09-09
Publication date: 1992-05-20
Also published as: GB9119236D0; CA2050659A1

Abstract

The conditioner (1) treats feed with steam and includes a plurality of steam lines (10) that can inject steam into a chamber (3) having inlet (5) and outlet (7) openings. Located within the chamber is a rotatable shaft (13) supporting a helical stainless steel ribbon (25) arranged coaxially with the shaft and extending for approximately three quarters of the length thereof. When the shaft is rotated, the ribbon acts as a conveyor and moves the feed towards the outlet (7). The shaft also supports a plurality of paddles (32) which create a counterflow of feed to cause the feed to mix with the steam. Also mounted on the shaft are a plurality of beaters (37) which agitate the feed steam mixture to create an even and continuous discharge of feed. A weir (37) is mounted upstream of the outlet (7) to prevent escape of the steam by ensuring that the upstream portion of the chamber is filled with feed. The weir (37) also provides an even flow of feed to the outlet opening. <IMAGE>

Description

"FEED CONDITIONER APPARATtJS" BACKGROUND OF THE INVENTION This invention relates, generally, to the treatment of animal feed and, more particularly, to an apparatus for conditioning feed using steam heat.

To prepare animal feed a variety of rat feed materialsare granulated and delivered to a mixer where the granulated raw materials are mixed together to create a desired feed mix. One prior art device for mixing the granulated material consists of a chamber, having an inlet opening and an outlet opening. A rotatable shaft is mounted in the chamber and supports a helical ribbon which moves the granular feed generally from the inlet opening toward the outlet opening. The shaft also supports a plurality of fixed paddles which retard the flow of granular material caused by the ribbon to thereby mix the various raw materials. While this device can mix granulated material, it cannot be used to condition feed.

The mixed feed is then delivered by conveyor to a conditioner apparatus where the feed mix is treated with steam heat. The feed is heated to soften it so it can be more efficiently compressed into salable pellets by a pelletizer, to kill salmonella organisms that may be present in the feed and to increase the feed efficiency in animals.

To decontaminate the feed the temperature of the feed is raised by mixing it with'steam in a conditioner apparatus to a level that will kill the salmonella organism. In order to be effective in controlling salmonella in feed, the feed must be maintained at approximately 190 degrees F for 1 1/2 minutes at approximately 15% moisture or at 193 degrees F for 1/2 minute at approximately 15% moisture. Using steam to transfer the heat results in condensation of the steam and a corresponding increase in the moisture content of the treated feed. In known devices, in order to obtain the high temperature level necessary to consistently kill the salmonella organism, the moisture content of the mash must be increased beyond the clog point of the pellet mill and is therefore unacceptable.

Moreover, the starch in the feed will begin to gelatinize at approximately 180 degree F. Gelatinization of the starch makes it more easy to digest and increases feed efficiency. Therefore, in addition to decontaminating the feed, steam treatment, if performed at a high enough temperature, also enhances the efficiency of the feed in animals.

Finally, exposing the feed to steam heat prior to delivering it to the pelletizer, softens the fibers in the feed.

The softer feed requires less mechanical pressure to be formed into pellets than untreated feed. Thus, proper steam treatment of the feed also increases the efficiency of the pelletizer.

In the known prior art conditioner, the desired temperature level can not be maintained at a level sufficient to provide the potential benefits associated with the steam treatment of feed. This is due to the fact that the known conditioner apparatus is an open system which allows a steady and constant ingress and egress of feed. While the steady flow of feed provided by this open system is necessary to maintain the proper supply to the pelletizer, it also allows the steam to escape with the exiting feed stock such that the feed is not heated uniformly and for a sufficient time period. As a result, not all of the feed is raised to a temperature level high enough and for a long enough period of time to kill the salmonella organism, gelatinize the starch and soften the fibers.

An improved feed conditioner that can control the time, temperature and moisture level during the steaming process is therefore desired.

OBJECTS OF THE INVENTION It is a general object of the invention to provide an improved feed conditioner that can reliably and efficiently condition feed using steam heat.

It is another object of the invention to provide a feed conditioner that can raise the temperature of the feed to a level high enough to kill salmonella organisms.

It is a further object of the invention to provide an improved feed conditioner that can retard the escape of steam therefrom.

It is a still further object of the invention to provide a feed conditioner which can control the moisture level of the feed during the steam heating process and the length of time that the feed is exposed to the steam. Increasing the retention time in the conditioner to approximately 1 minute.

It is another object of the invention to increase the retention time of the feed in the feed conditioner.

It is yet another object of the invention to provide a feed conditioner that can provide a steady and continuous flow of feed.

It is a further object of the invention to provide a feed conditioner that gelatinizes the starch in the feed stock to increase its digestibility and softens the feed to increase mill production.

It is a still further object of the invention to provide a feed conditioner that increases the mixing of the feed and steam such that the temperature of all the feed is uniformly raised to a desired level.

Other objects of the invention, in addition to those set forth above, will become apparent to one of ordinary skill in the art from the following description of the invention.

SUMMARY OF THE INVENTION The feed conditioner of the present invention overcomes the above noted shortcomings of the prior art. It includes a horizontally disposed chamber having an inlet opening at one end and a outlet opening at the opposite end thereof. A plurality of steam lines are provided proximate to the inlet opening such that a variable amount of steam can be injected into the chamber. A rotatable shaft is located within the chamber and extends from adjacent the inlet opening to a position adjacent the outlet opening. The shaft is supported in bearings and is rotated by a variable speed drive motor. The shaft supports a helical stainless steel ribbon arranged coaxially with the shaft and extending for approximately three quarters of the length thereof.

When the shaft is rotated, the ribbon moves the feed from the inlet opening towards the outlet opening. The shaft also supports a plurality of paddles which retard the flow of feed and enhance the mixing of the feed and steam. The paddles are adjustably mounted on the shaft so as to create a counterflow action tending to move the feed in the opposite direction to enhance mixing. Also mounted on the shaft at a position adjacent to the outlet opening, are a plurality of beaters which agitate the feed/steam mixture to create an even and continuous discharge of feed. A weir is mounted upstream of the discharge opening to ensure that the upstream portion of the chamber is filled with feed to thereby retard the escape of the steam from the chamber via the discharge opening such that the temperature level in the chamber can be maintained. The weir also provides an even flow of material to the discharge opening. By adjusting the speed of rotation of the shaft, the position of the paddles, the size of the weir and the amount of steam injected, the performance characteristics the conditioner can be varied to achieve substantially uniform steam treatment of feed to kill salmonella, gelatinize starch and soften the feed fiber.

BRIEF DESCRIPTION OF ThE DRAWINGS Figure 1 shows a perspective view of the feed conditioner of the invention in association with a feed conveyor.

Figure 2 shows a partial cut-away side view of the feed container of the invention exposing the internal structure of the device.

Figure 3 shows a section view taken along line 3-3 of Figure 2.

DETAILED DESCRIPTION OF THE INVENTION Referring more particularly to the drawings, Figure 1 shows the conditioner of the invention 1 consisting of a cylindrical chamber 3 having an inlet opening 5 and an outlet opening 7. Located above chamber 3 is a conveyor 9 which delivers feed to the inlet opening 5. Both chamber 3 and conveyor 9 can be provided with steam jackets if necessary. As will be understood, a steam jacket consists of a compartment surrounding the outerwalls of the chamber 3 and/or conveyor 9 into which steam can be fed to preheat the chambers when used in cold environments. The outlet opening 7 is located above the intake of a pellet mill where the feed pellets are formed from the conditioned feed.

A plurality of steam pipes 10 are provided to deliver steam to the interior of chamber 3 and are located adjacent to the inlet opening 5. Pipes 10 are provided with valves 12 such that the amount and rate of steam delivered to the interior of chamber 3 can be controlled.

As best shown in Figure 2, the conditioner 1 includes a shaft 13 extending between the end walls 15 and 17 of chamber 3 and rotatably supported in bearings 19 and 21. A suitable variable speed motor 23 is operatively connected to shaft 13 to rotate shaft 13 in the direction of arrow A.

Mounted coaxially on shaft 13 is a stainless steel ribbon 25 having a helical shape. The ribbon 25 is connected to shaft 13 by rods 29 dimensioned such that ribbon 25 is disposed closely adjacent to the interior surface 4 of the wall of chamber 3. As is evident from Figure 2, ribbon 25 extends from the end wall 15 adjacent to the inlet opening 5 a distance less than the length of shaft 13. Ribbon 25 is arranged such that when shaft 13 is rotated in the direction of arrow A it acts as a conveyor to move the feed from the inlet opening to the outlet opening (rightwardly as viewed in Figure 2).

Mounted on each of rods 29 are paddle assemblies 31.

Each paddle assembly 31 includes a paddle 32 having a collar 33 fixed to each side thereof. The collars 33 and paddles 32 have a bore located therein such that the paddle assemblies 31 can be rotated and reciprocated along rods 29. The collars 33 include bolts 35 which engage the rods 29 to lock the paddle assemblies in the desired position. As is evident from Figure 2, paddles 32 are positioned such that when shaft 13 is rotated in the direction of arrow A the paddles 32 will tend to move the feed in the direction from the outlet opening 7 towards the inlet opening 5 (leftwardly as viewed in Figure 2).

Thus, the combined effect of ribbon 25 and paddle assemblies 31 is to agitate and stir the steam and feed mixture to insure that the feed is evenly heated. While the paddles 32 create a counterflow of the feed opposed to the'movement of the feed caused by ribbon 25, the net effect of the operation of ribbon 25 and paddles 32 will be to continuously move feed from the inlet opening 5 toward the outlet opening 7.

Also mounted on shaft 13 in the area between the end of ribbon 29 and the end wall 17 are plurality of beaters 35. The beaters 35 include rods screwthreadably engaged with shaft 13 and having blade portions 37. Blade portions 37 are angled with respect to shaft 13 such that the rotation of shaft 13 causes blade portions 37 to move the feed in the direction from the inlet opening to the outlet opening and are adjustably mounted so that the rate of flow of the feed can be adjusted. In a preferred form of the invention the blade portions 37 of the upstream beaters are made wider than those of the downstream beaters to facilitate the conveying of the feed. The beaters 35 insure that an even and continuous flow of feed is delivered from the outlet opening to the pelletizer.

As best shown in Figures 2 and 3, a weir 38 is fixed to the interior surface 4 of the wall of chamber 3 between the first and second set of beaters 35. The weir can be welded to surface 4 or be removably secured thereto by screws 42. Screws 42 extend through holes formed in flanges 44 which extend from surface 4 and engage holes 43 formed in the weir 38. A plurality of holes 43 are provided such that weir 38 can be adjustably positioned in chamber 3. Weir 38 consists of a steel plate having a first, centrally located cut-out 40 for receiving shaft 13. Weir 38 is configured to block approximately 6 758 of the chamber to thereby retard the flow-of feed between the inlet opening 5 and outlet opening 7. The effect of weir 38 is to ensure that the area of the chamber 3 upstream of weir 38 is filled with feed.

As a result, the steam will be trapped upstream of weir 38 to enhance and prolong its mixing with the feed. The weir 38 also ensures that a steady and continuous supply of feed is delivered to outlet opening 7 such that surges in the feed supplied to the downstream pelletizer are avoided.

The combined effect of the ribbon 25, paddles 32, beaters 35 and weir 38 is to ensure that the feed fills the upstream portion of chamber 3, that the steam is mixed evenly with the feed for a prolonged period of time and that a steady flow of feed is provided to the feed mill. By varying the rotational speed of the shaft 13, the angle and sizes of the paddles 32, the amount of steam delivered to the chamber and the size of the opening in weir 38 the temperature level of the feed, its moisture content, and the time of heating can be varied. As a result, the device of the present invention can achieve and maintain the necessary conditions for decontaminating, gelatinizing starch and softening the feed. It has been found that a rotational speed of the shaft of between 10 and 70 rpm combined with a rate of delivery of steam of 25-100HP depending on the mill production, and paddles angled backwards at approximately 25-45 degrees allows the feed conditioner of the invention to heat the feed product to over 200 degrees for 3/4 to 1 1/2 minutes while maintaining less than a 17% moisture change and providing a continuous and steady supply of feed to the pellet mill.

While the preferred embodiment of this invention has been shown and described in some detail, it will be understood by one of ordinary skill in the art that this description and the accompanying drawings are offered merely by way of example, and that the invention is to be limited in scope only by the appended claims.

Claims

What is claimed is:

1. An apparatus for conditioning feed by steam treatment, comprising: a) a chamber having an inlet and an outlet; b) means for introducing steam into said chamber; c) first means supported in the chamber for moving the feed in a first direction, second means supported in said chamber for moving the feed in a second direction opposite to said first direction whereby the net effect of the first and second means is to mix the steam and the feed and move the feed in a downstream direction from said inlet toward said outlet; and d) third means supported in said chamber adjacent to said outlet for a blocking the escape of steam and flow of feed to the outlet.

2. The conditioner according to claim 1, further including a rotatable shaft supporting said first means and said second means.

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3. The conditioner according to claim 2, wherein said the first means includes a conveyor.

4. The conditioner according to claim 3, wherein said conveyor consists of a helical ribbon spaced from said rotatable shaft and disposed adjacent to the interior wall of said chamber.

5. The conditioner according to claim 2, wherein said second means includes d plurality of paddles.

6. The conditioner according to claim 5, wherein said paddles are adjustable mounted such that their angle relative to the second direction can be varied.

7. The conditioner according to claim 2, wherein said third means includes a weir located downstream of said inlet.

8. The conditioner according to claim 7, wherein the weir comprises a plate fixed in said chamber for restricting the flow of feed between the inlet and outlet.

9. The conditioner according to claim 1, further including a fourth means for agitating the feed.

10. The conditioner according to claim 9, wherein said fourth means includes a plurality of beaters.

11. The conditioner according to claim 10, wherein said beaters include blade portions for moving the feed in said first direction.

12. The conditioner according to claim 1, wherein said the first means includes a conveyor.

13. The conditioner according to claim2, wherein said conveyor consists of a helical ribbon disposed adjacent to the interior wall of said chamber.

14. The conditioner according to claim 1, wherein said second means includes a plurality of paddles.

15. The conditioner according to claim 14, wherein said paddles are adjustably mounted such that their angle relative to the second direction can be varied.

16. The conditioner according to claim 1, wherein said third means includes a weir located downstream of said inlet.

17. The conditioner according to claim 2, further including means for rotating said shaft.

18. The conditioner according to claim 17, wherein said means for rotating includes a variable speed motor.

19. The conditioner according to claim 1, wherein said means for introducing steam includes a means for varying the amount of steam delivered to the chamber.

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20. The conditioner according to claim 2, wherein said shaft extends between said inlet and said outlet.

21. A conditioner apparatus for steam treating feed, comprising: a) a chamber having an inlet and an outlet; b) means for introducing steam into said chamber; c) a rotatable shaft disposed in said chamber; and d) first means for moving the feed in a first downstream direction, second means for moving the feed in a second direction opposite to said first direction, third means located adjacent said outlet to create a blocking action which substantially retards the escape of steam through the outlet, said first and second means being mounted on said rotatable shaft whereby rotation of said shaft mixes the steam and feed to condition the feed.

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22. The conditioner according to claim 21, further including means for rotating said shaft.

23. The conditioner 'according to claim 21, wherein said first means includes a helical ribbon.

24. The conditioner according to claim 21, wherein the second means includes at least one paddle.

25. The conditioner according to claim 21, wherein the third means includes a weir located downstream from said inlet.

26. The conditioner according to claim 21, further including a fourth means including at least one beater having a blade portion for moving the feed in the first direction.