JPS5982901A - Double-temperature spray dryer for heat sensitive product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method and apparatus for spray drying liquid food products, and more particularly to a method and apparatus for drying heat-sensitive food products without altering the heat-sensitive properties of the food product. There are a number of food products that are used in powder form and the powder is prepared by a spray drying process. In spray drying, the food product in liquid form is passed through an atomization nozzle that directs the atomized particles into a heated, moving air stream. No. 2,117.9211 (1), owned by the assignee of the present invention.
The atomizing nozzle has different speeds of airflow, including a high-speed airflow immediately surrounding the atomization nozzle and a low-floor airflow surrounding the high-speed airflow. A fog dryer that circulates heated air through the air is described.

With the improved method and apparatus of the present invention, it has been found that providing a high velocity flow of high 2:IL and a low velocity flow of low temperature results in a significant improvement in the retention of 5 mist-dried products by GC. Ta.

In the production of powdered egg products and powdered egg products, this improved method can be used without changing the heat sensitivity of these products, such as taste or appearance, i.e., without blackening or fading. I'J' has been found to work by having a high temperature air stream immediately surrounding the atomized particles being emitted from the one-rod nozzle and a vortex air stream surrounding these streams to reduce the drying time. However, at the same time, the dried product itself is removed from the drying chamber at low flow. (tl Really cold to eliminate darkening of the product caused by these surfaces becoming too thick.Product wrapping equipment1llll! Due to the low temperature /ili
Thermoplastic products with a tendency to set when 'l l&' are light are handled satisfactorily without such undesirable setting. Various foods, such as products containing high levels of reducing sugars, such as glucose or fructose gold, may dry even more satisfactorily without clumping, darkening, or other symptoms. Such sugar products are
When exposed to high temperatures during drying, it binds to proteins.

and is prone to coloring effects.

It is therefore an object of the present invention to provide an improved method and apparatus for spray drying food products, particularly heat-sensitive food products.

Another object of the present invention is to provide an improved dual temperature method and apparatus for spray drying basins.

Preferred embodiments of the invention are selected for purposes of illustration and description and are shown in the accompanying drawings.

1.2. Improved air dryer and its operating power. A general description will be given with reference to the following.

The spray dryer, which will be explained later, is located in a suitable platform! ! The spray dryer 1 is installed in a regular manner, and the air used for drying is supplied from outside and returned to the outside.For this purpose, the spray dryer 1 has a There is a long air supply 2 for air supply. To the same shell, an elongated air outlet 1 is connected by suitable exhaust piping to the outlet end of the spray dryer. Dryer 1
There is a heater device 5 for changing the crystallinity of the air at the inlet 2 from -F9 to the desired dry product 11 degrees, as fully explained below. Air is sent to and passes through the heater device 5 by two air blowers 6 and ducts I and 7; A commercially used type of filter is found in )Using 8.

The heated air in the air stream of different temperatures is directed downwardly through the air distribution plate 10 and into the plenum 1 which communicates with the drying chamber 11 of the dryer j. The air distribution plate 10 is connected to a suitable source 23 of the liquid to be dried via a regulated fluid supply device 111i and is equipped with a number of atomizing nozzles 12. The construction and operation of the Tough 1-7, heating device 5, air distribution plate 10, and associated atomizing nozzle 12 will be described in detail below.

Drying chamber 11id,; - complete removal of dried or powdered product from the air stream and a discharge end j which allows the separated air to be traced upwards around the air outlet) ↓;
It ends with 5. The dried product falls on the floor of the drying chamber 11 and is transferred to the bottom of the publication chamber 15 by the drag device 1G in the direction of the air flow. An underwater auger 17 conveys the dry product to a removal auger 1g which sends the dry powder to one vibrating screen.

Final removal of remaining dry goods in the air stream takes place at the outlet filter 20, which includes a filter bag 21.

Air supply equipment for plenum in two different by-products is 1
Two completely independent air supply bags at different temperatures instead of one supply with a separate duct system
It may be obtained by using t.

Air heating and distribution The air distribution plate 10 consists of two ? Atomized product 1'J' (must be mixed efficiently with dry air heated to A highly efficient drying process can be achieved by using a controlled drying pan when exposed to the desired airflow to protect heat-sensitive foods or other products from thermal damage.

The air distribution plate 10 according to the present invention is arranged such that the air inlet end 'Iff: of the drying chamber 9 is bent, and the flow of the 2N temperature air in the i'lii direction from the plenum 13 through the drying chamber 11 is almost parallel. It faces the side wall 30, ceiling 1 and floor 22 of the drying chamber 11. A number of product atomizing nozzles 12 are attached to the air distribution plate 10. They are connected to a source of liquid product 23 via a fluid supply device lll. Each of the atomizing nozzles 12 is mounted in a downstream direction from the air distribution plate 10 over a relatively large orifice or air nozzle 52 . Air nozzle 2 passes drying air past the atomization nozzle 12 at relatively high velocity and high temperature to pick up the atomized particles from the atomization nozzle 12 to initiate and complete most of the particle drying. let

The air distribution plate 10 also includes a large number of substantially uniformly spaced comparisons which pass low-velocity, low-temperature air in the form of an air stream that surrounds the aforementioned air stream from the larger nozzle 2. There are 4 small air nozzles. These low-velocity air flows suppress the backflow or backlash of high-velocity air in the zone adjacent to the air distribution plate 10 and eventually mix further downstream with the high-velocity air used in the final stage of particle drying.

Heated dry air is supplied to the large air nozzle 2.

Only the 7' nozzle 52 shown in FIGS. 2 and 1 is supplied by a source of air. Air supply duct 1
-7U: divided into two separate channels connecting the air blower 6 to the plenum 15; Separate air supply channel) 10, separate chamber It 1 in plenum 1
leading to. The chamber 11 is formed by an outer wall opening 2 of the plenum 13 and an inner partition plate 5 extending from the top of the plenum 13 to the bottom. The large air nozzle 2 extends through a suitable hole 1111i in the partition plate 5+15.

The drying air is controlled independently by a suitable steam coil heater or electric or other thermostatically controlled heater) 15 placed in the channel) 40. (Aj is done. This is nozzle 5
2 and past the atomizing nozzle 12 at a predetermined air velocity and air temperature.

As already pointed out, the velocity of this air is greater than the velocity of the air flowing through the series of small nozzles 34, and the velocity of this air is greater than the velocity of the air flowing through the series of small nozzles 1).
! il'i I'! It is considerably more expensive for dry products.

Also as illustrated in FIGS. 2 and 11.

The air supply to the small nozzle 5+1 is through the individual duct channel l16'f! : This air is sent to the D71 section of the purinoum 13 in front of the partition plate +13, and then passes only through the large number of small air nozzles 4 from the solinum 15. Smaller channel 14G and nozzle 511ij: imparts a lower air velocity to the air exiting nozzle 311. Improvements already mentioned -
4, a lower air temperature is used for the air in the nozzle 51↓. In some cases this air may be supplied entirely at its normal intake temperature without additional heating;
steam or electric or electric heater 117i channel)
(L of air passing through a small nozzle 5++ fitted in 6)
! ll′1 degree may be controlled as desired.

FIG. 5 shows another device for supplying air at different velocities and altitudes through a large nozzle 32 and a small nozzle 511 7
ing. In this embodiment, the air supply duct L-118
There are 11 large channels and 50 small channels. An adjustable damper 51 connects one of the large channels (containing this or other heaters 52) to the small channel 50. Channel by this! High 'lr'A in 19
A portion of the drying air is adjustable into the air stream flowing through the channel 50 and the heated air channel '49'
C ili' can be set to a certain desired rate of the temperature of the air entering the free numeral 1.

A typical air distribution plate, such as the plate 10 described above having six spray nozzles 12 and six large (diameter O)↓8c1++ (12 inches) air nozzles 52, is the plate 10.
Approximately 560・1 attached at −& intervals throughout
- Will have a large (2 inch diameter) air nozzle 54.

It will be appreciated that an improved dual 1M+: degree air dryer is provided that is particularly useful for dry powdered products, including heat-sensitive food products, where control of the dry wet layer is desirable. Improved dryer operation, including improved control of drying air flow and heating, maintains the integrity of the finished powder product and prevents discoloration.

In an example, a heavy temperature dryer is used to dry eggs with a liquid base of 8% complete eggs and 1%
It was used with a heat-baked egg product containing 5% corn syrup. Air flow 1 following six hot air inlet nozzles 32 surrounding six spray drying nozzles 12: 2 at a humidity of 160°C
97 +#2J/mm tep; ivy O low temperature person 1]
The air flow rate through nozzle 5 II f is 2! at 60°C! IV
It was '+2.5 nr,''/min at 1111 degrees at Nodame's exit, 628-655 degrees.
℃, and the packaging temperature of the dry product without further cooling was 5-146℃. After 100 hours of operation under these conditions, the product was very good with only a small amount of dry base remaining on the walls, ceiling and floor with no change in one color.

Example 2 Inactivated Ease 1=, which is very sensitive to heat-induced darkening, was spray dried. This product was spray dried under dual temperature drying conditions similar to those described in Example 1.

There was no change in the color or taste of the finished dried product during the 120 hour drying run.

[Brief explanation of drawings]

FIG. 1 is a flowchart of the method and apparatus of the present invention;
Figure 4 shows a schematic diagram of a spray dryer according to the present invention, Figure 4 is a plan view of the spray dryer shown in Figure 2, and Figure 4 shows a device for supplying air at different temperatures to the spray drying chamber through an air distribution plate. Enlargement 1. Figure 5 is an enlarged view of another implementation of a device for dividing the air supply and temperature in the air distribution plate.
-Silk 11'I? ■Figure j. 5--Iriki solar heating device, 7--Duc l-, 10--Air distribution plate, 11--Drying chamber, 12--1 Atomization nozzle, 1--Plinum.

Claims (1)

Claims: 1. An air distribution device for a hot air dryer used between an air supply device and a drying chamber to direct air to the drying chamber at two different temperatures, comprising a plate member. A device consisting of a plenum divided into two compartments and a separate air supply channel connected to each plenum compartment, supplying air at different temperatures to both plenum compartments. heating means in at least one of said two channels; one or more first pipes installed at regular intervals on the plate member and communicating with one section of the plenum for supplying air at a higher temperature of the different temperatures to the drying chamber; elongated tubular nozzles mounted on said plate member at substantially uniform intervals and communicating with the other Greenham compartment to direct low temperature air into said drying chamber (J);
t: a plurality of relatively small tubular nozzles for feeding. a liquid atomizer attached to said first elongated nozzle; an air distribution device comprising: a combination of: the first and second nozzles having their axes substantially parallel to the plate member; 2. The air distribution device according to claim 1, characterized in that the heating means are provided in both of the two channels. An air distribution device according to claim 1, wherein the two channels are provided with means for regulatably transferring air from one channel to the other. 4. The air distribution device according to claim 1, wherein the high temperature dry air is supplied at a temperature of about 160C and the low temperature dry air is supplied at a tj quality of about 60C. 5. Air distribution device according to claim 1, characterized in that liquid egg product is delivered to the liquid atomizer. G. 1iii. The air distribution device according to claim 1, wherein the liquid fermentation fI product is fed to the liquid atomizer. 7. The flow rate of air passing through the first nozzle and past the liquid atomizer is about 297? The air distribution device according to claim 1, characterized in that n, I/time. 8 The flow rate of air passing through the second nozzle is approximately 11
2.5 m”/n+ii+
An air supply device, (I) a drying/gravel chamber, and a plenum divided into three sections (I: 1 (1 for II plate members)). (iii) Supplying air at a temperature of J to both plenum sections. , a separate air supply channel connected to each plenum compartment; (1) heating means in at least one of said two channels; If it is located in the 7th position, it will communicate with the two sides of the above-mentioned Nori Nano.
,'! 1: B (
one or more first;jlI] long tubular nozzles; (■1) The first and second plates are arranged on the plate member at substantially uniform intervals and communicated with the other Zolinum compartment, and the plate members are placed parallel to each other. a plurality of relatively small tubular nozzles that supply all of the air in two nozzles; and a liquid atomizer that is defeated by the first narrow nozzle. 10. Means for directing the drying chamber into the drying chamber at a temperature of 10.degree. 11, wherein the two channels are provided with means for fully adjustable transfer of air from one channel to the other. 12. The drying air is supplied at a crystallinity of about 160°C, and the low temperature drying air is supplied at a crystallinity of about 60°C. The air dryer as described in 15. The flow rate of the air that passes through the entire first nozzle and passes through the liquid atomizer described in q?i is approximately 29?yn''/rm.
The air dryer according to claim 12, characterized in that: n. 14. The air dryer of claim 12, wherein the air flow rate through the second nozzle is approximately 112.5 m''/h.