IES990474A2 - A process and apparatus for producing flaked animal fodder - Google Patents

Abstract

A flaked cereal animal fodder is produced by injecting warm water at a temperature 45°C to 55°C in an auger conveyor which delivers the grain to a damping bin. Soaked grain is dumped into a grill inlet hopper having perforated walls through which hot air passes through pre-heat the grain to a temperature in the range 30°C to 40°C as it is fed to a grill conveyor. The grain is conveyed by the grill conveyor under burners until the temperature reaches approximately 100°C and is subsequently flaked in a roller mill. <Figures 1(a) & 1(b)>

Description

“A Process and Apparatus For Producing Flaked Animal Fodder” The invention relates to a process and apparatus for producing animal fodder, more particularly flaked cereal fodder.

Such a process is described in British Patent Specification No. GB2309150 adowgate). In this process, grain is wetted on a wetting conveyor, is then soaked, q and is then cooked. The process includes a pressure heating stage in which pre-heated H rial is delivered to an autoclave in which it is heated under pressure. The autoclave O £ preceded by a pre-autoclave. In the autoclave itself, pressurised steam is used to heat material and the temperature of the material is approximately 100°C as it is delivered tjie cooker. The material is cooked in the cooker for between 50 and 60 minutes at a ierature of between 90°C and 110°C. .·<) c c b sV &3 It is an object of the invention to provide a process which is simpler, which has reduced energy consumption, and which has a shorter production cycle.

Another object is to provide for production of a flaked animal fodder which is more easily digested by younger animals to optimise the nutritional content.

According to the invention, there is provided a process for producing flaked cereal animal fodder, the process comprising the steps of:IE990474 -2conveying grain to a damping bin and delivering warm water at a temperature in the range of 45°C to 55°C into the grain as it is being conveyed; soaking the grain in the damping bin for a time period in excess of 12 hours; delivering the soaked grain into a grill inlet hopper having perforated walls through which hot air is passed to heat the soaked grain to a temperature in the range of 30°C to 40°C as it is being fed to a vibrating grill conveyor; the vibrating grill conveyor conveying the grain under burners until the temperature reaches approximately 100°C. rolling the grilled grain in a roller mill; cooling the rolled grain; and delivering the cooled and rolled grain to an outlet.

In one embodiment, the warm water is delivered to the grain by injection into auger 20 conveyors.

Preferably, the warm water temperature is approximately 50°C.

In one embodiment, the grain is soaked in the damping bin for approximately 24 hours.

Preferably, the hot air is delivered to the hopper from an enclosure over the grill burners. In ane embodiment, the grill conveyor is controlled to provided a grill time of 50 to 70 seconds.

IE990474 -3Preferably, the rate of delivery from the hopper onto the conveyor is controlled according to sensed grain temperature at the roller mill.

In one embodiment, the grain is cooled in a horizontal flat bed cooler having two decks 5 and a dust extraction system delivering fines to a recycling container.

In another embodiment, the cooled grain is filtered in a sieve to route fines to a recycling container and graded flakes to different product destinations.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompany drawings in which:Figs. 1(a) and 1(b) are together a flow diagram illustrating a production process and apparatus of the invention; and Fig. 2 is a diagram showing a grill conveyor hopper in more detail.

Referring to the drawings, there is illustrated a process and apparatus for producing flaked cereal animal fodder. The raw material used is a whole grain which is one or a combination of maize, barley, wheat, and peas. The grain is fed from a buffer bin (not shown) via a drop 1 to a sieve 2 at which fines, over-size grains, and foreign matter is filtered out and dumped to a bin 3. The output of the bin 3 is fed back to separate processes which utilise its contents. Dust extraction is performed by an extraction system 4 comprising a cyclone 5 which delivers fines to the bin 3.

IE990474 -4The cleaned or graded grain from the sieve 2 is fed to an elevator 6, which in turn delivers the grain to damping bin feed conveyors. These include a conveyor 10 for a second set of three bins 25, 26, and 27 and conveyors 11 and 12 feeding a first set of such bins 13, 14, and 15. The grain is delivered to the bins according to the particular batch requirements by setting a diverter value. The conveyors 10, 11, and 12 are of the type comprising augers.

An important aspect of the process is that the grain is moistened en route to the bins by a water delivery system comprising a tank 20 and control valves 21 and 22 and associated pipe circuits and nozzles 23 and 24. The water temperature is in the range 45°C to 55°C and is preferably 50°C. The water is injected at intervals into the conveyors 10 and 11. Because these conveyors comprise augers, there is excellent dispersion of water throughout the grain. The quantity of water is 7% to 8% by volume. It has been found that this water temperature and volume provides for excellent absorption through the outer grain shell. Good absorption improves heat penetration in the subsequent cooking steps.

As will be apparent from the diagram of Fig. 1(a). A second elevator 28 routes grain from the first set of bins to the second set. Thus, grain which needs to be soaked in a bin of each set is routed through both sets using the conveyors 11 and 12 and the elevator 28. Grain which only needs to be soaked in a bin of one set is routed initially on the conveyor 10 to the second set of bins. The second set of bins discharge onto conveyors 28, 29 and IE990474 -530 respectively. These conveyors feed a common conveyor 31 which in tum feeds an elevator 32 which delivers it to a gas grill feed conveyor 33.

Referring now to Fig. 1(b), the conveyor 33 feeds the soaked grain to one of two parallel processing lines comprising a grill 40, a roller mill 60, and a cooler 70. In each line, the soaked grain is fed to an inlet hopper 41 which delivers the soaked grain to a conveyor 42 vibrated by a motor 43. The grill 40 also comprises a set of gas burners 44 which generate infrared heat at a distance of 380 mm above the grain to bring the grain temperature to 100°C.

The grill 40 also comprises a hood 45 over the burners. Hot air is drawn from the enclosure formed by the hood 45 by a conduit 46 having an in-line fan to the inlet hopper 41. There is also a waste air extraction pipe 47 having a baffle for flow restriction. Referring now to Fig. 2, the hopper 41 is shown in more detail. The hopper 41 comprises an outer casing 50 and an inner mesh 51 shaped to provide a Venturi-like flow restriction.

The enclosure hot air is drawn through the conduit 46 by an exhaust conduit 52 having an in-line fan 53. It has been found that this arrangement provides excellent distribution of heat in the grain as it is delivered to the conveyor 42.

The hopper 41, by virtue of the hot air re-cycling, pre-heats the soaked grain from ambient temperature to a value in the range 30°C to 40°C. Thus, the soaked grain is delivered onto the conveyor 42 at an elevated temperature. This considerably improves productivity by increasing throughput and reducing energy consumption per tonne.. Heat IE990474 -6penetration in the grain is improved considerably by virtue of the manner in which the grain was previously soaked. The time for conveying under the burners is in the range 50 to 70 seconds is preferably 60 seconds. The moisture content at delivery to the roller mill is 16%.

The grain is then delivered to the roller mill 60 which breaks the starch molecules in the grains so that they do not re-form. The rollers of the mill 60 are fluted to improve effectiveness in pulling the grain through. The separation is adjustable to set the desired separation for the particular grain. There is a temperature sensor at the inlet to the mill 60, and a controller for the feeder of the hopper 41 automatically adjusts flowrate of grain to the conveyor 42 to achieve the desired temperature at the mill 60. Roller rotation is detected and if a jam occurs drive is automatically stopped.

The rolled grain is then cooled in a horizontal flat bed cooler 70 having upper and lower decks 71 and 72. The cooler 70 has side vents and air is drawn by an extraction fan 73 through the decks to a cyclone 74. The cyclone 74 provides fines for recycling.

The cooled grain is delivered to a sieve 80 which filters the grain. The sieve 80 has two decks. Fines are transferred to a separate process by a pneumatic conveyor 83. There are two product outlet conveyors, namely a chain conveyor 81 which delivers product to final destination bulk bins. A pneumatic conveyor 82 delivers the product to downstream processing plant. Air is delivered to the pneumatic conveyors 82 and 83 by an air blower 84.

IE990474 -7It will be appreciated that the invention provides a highly efficient production process, both in terms of energy consumption and utilisation of raw materials. Injection of warm water in the auger conveyors en route to the damping provides excellent absorption of water. This subsequently assists heat penetration in the grill to achieve a higher throughput per unit of energy consumed and also more uniform heat distribution in the grain. Also, the heat re-cycling in the grill helps to reduce energy consumption and lengthens the heating time to provide more gradual heat penetration. Excellent quality control is achieved by virtue of the feedback from the roller mill 60 to the feeder of the hopper 41.

The invention is not limited to the embodiments described but may be varied in construction and detail within the scope of the claims.

Claims (2)

Claims

1. A process for producing flaked cereal animal fodder, the process comprising the steps of:conveying grain to a damping bin and delivering warm water at a temperature in the range of 45°C to 55°C into the grain as it is being conveyed; soaking the grain in the damping bin for a time period in excess of 12 hours; delivering the soaked grain into a grill inlet hopper having perforated walls through which hot air is passed to heat the soaked grain to a temperature in the range of 30°C to 40°C as it is being fed to a vibrating grill conveyor; the vibrating grill conveyor conveying the grain under burners until the temperature reaches approximately 100°C. rolling the grilled grain in a roller mill; cooling the rolled grain; and delivering the cooled and rolled grain to an outlet.

2. A process as claimed in claim 1, wherein the warm water is delivered to the grain by injection into auger conveyors, and wherein the warm water temperature is approximately 50°C, and wherein the grain is soaked in the damping bin for approximately 24 hours, and wherein the hot air is delivered to the grill inlet hopper from an enclosure over the grill burners, and wherein the grill conveyor is controlled to provided grill time of 50 to 70 seconds, and wherein the rate of delivery from the grill inlet hopper onto the conveyor is controlled according to IE990474 -9sensed grain temperature at the roller mill, and wherein the grain is cooled in a horizontal flat bed cooler having two decks and a dust extraction system delivering fines to a recycling container, and wherein the cooled grain is filtered in a sieve to route fines to a recycling container and graded flakes to different product destinations. A process substantially as described with reference to the drawings. Animal fodder whenever produced by a process as claimed in any preceding claim. Production apparatus substantially as described with reference to the drawings.