US2068841A - Belt delivery spray drier - Google Patents

Description

`Ian. 26, 1937. w g,` BOWEN ET AL 2,068,841

BELT DELIVERY SPRAY DRIER Filed June 22, 1934 [wir ATTORNEYS Patented Jan. 26, 1937l PATENT OFFICE BELT DELIVERY SPRAY DRIER William Spencer Bowen and Julius Freeman, Westfield, N. J.

Application June 22,' 1934, Serial No. 731,892

3 Claims.

The present invention relates to spray drying mechanisms and embodies, more specically, an improved spray drying device wherein the particles which are dried are delivered directly from the drying chamber to a belt conveyor and carried forward through a cooling chamber to be discharged at the outlet end of the chamber. It is proposed to provide a mechanism of the above character by means of which substances may be effectively dried and received by a conveyor mech-v anism which carries a substance through a cooling or belt chamber whereby the substance will fall upon a cool surface from the drying chamber. This is particularly important in drying hygroscopic or other products which are delicate and contain sugar, f such as molasses, fruit juices, dates, bananas, etc. These products have low melting points and unless cooled rapidly upon drying are apt to cake into hard masses. Also being very hygroscopic, the cooling air must be dried preferably below 40% relative humidity.

Accordingly, an object of the present invention is to provide a drying device by means of which -substances may be dried and received directly by a relatively cool surface upon which the substance passes through a cooling chamber to be discharged at a desired point.

A further object of the invention is to provide a device of the above character wherein the drying and vcooling chambers are so related as to enable the dried particles to fall directly` upon a belt in the cooling chamber, the belt and chamber being cooled by gases which flow counter to the travel of the material from the drying chamber and thus cool the particles more effectively.

Further objects, not specifically enumerated above, will be apparent as the invention is described in greater detail in connection with the accompanying drawing, wherein:

Figure l is a view in section, taken on line I-"-I of Figure 2, and looking in the direction of the arrows, showing a drying and cooling mechanism constructed in accordance with the present invention.

Figure 2 is a plan view, partly broken away and in section, showing the device of Figure 1.

Figure 3 is a View in section, taken on line 33 of Figure l, and looking in the direction of the arrows.

With reference to the above drawing, a spray drying device is shown at Ill and provides a drying chamber I I, at the top of which a spray head or micronizer I2 is provided. About the spray head an air inlet head or nozzle I3 is provided receiving air from an inletduct I4 at the top of the chamber. At the bottom of the chamber an inwardly sloping apron I5 is provided which directs the dried particles through a gas outlet chamber I6. The outlet chamber I 6A surrounds the apron I5 and causes the latter toibe properly 5 spaced from a belt conveyor which is shown in dot and dash lines at I1 in Figure 1. 'I'his conveyor is received within a belt or cooling chamber i8, upon which the drier I0 is mounted. The chamber I8 is formed with an opening I9 about 10 which the drier is mounted in order that the dried particles may fall directly from the drying chamber onto the belt conveyor Il.

A supporting plate or table 20 is provided in the drying chamber and serves as a supporting l5 means for the belt which passes over end guide rollers 2| and 22. Either of these guide rollers may be driven from a suitable power source and idler rollers 23 may be provided to support the lower span of the conveyor between the rollers 20 2i and 22. An idler roller 2d may also be provided adjacent the roller 22 and a rotary brush 25 is provided for sweeping the belt clean of particles which may adhere thereto during the travel of the belt from the outlet of the drying chamber 25 to the rotary brush.

In order that particles may be removed from the belt, a nozzle 2li is provided adjacent the roller 22, this nozzle receiving air from a manifold and duct 2l and directing the air jet against 30 the belt tangentially thereof in order that particles may be blown ofi of the belt and into an outlet duct 28. As noted above, if any particles continue to adhere to the belt the brush 25 sweeps them off and discharges them into an 35 outlet 29.

The belt chamber housing I8 completely encloses the belt and causes the cool air from the nozzle 26 to flow through the chamber and into the gas outlet chamber I6. From the chamber 40 i5, the air iiows beneath the apron I5 and through openings 30 into an outlet pipe breeching 3|. In this fashion, cooled dry air enters the system through the nozzle 265 and leaves through the openings 3l! and breeching 2i. Inasmuch as the belt is completely housed in the belt chamber, it is cooled by the ilow of cooled dry air from the nozzles 26 through the housing I8 and in this fashion, the dried products will 50 fall on a cool surface presented by the belt. This is of great importance in drying delicate products containing sugar and having low melting points. Unless these products are .cooled rapidly upon drying they are apt to cake into hard 55 masses. Being very hygroscopic. these masses must be -cooled by dry air.

While the invention has been described with specic reference to the accompanying drawing, it is not to be limited, save as defined in the appended claims.

We claim as our invention:

l. A drying mechanism comprising a drying chamber, a cooling chamber associated therewith whereby particles may fall from the drying chamber into the cooling chamber, a belt in the cooling chamber to remove particles therefrom, and means to direct a cooling uid against the belt to remove particles therefrom, the iiuid subsequently being directed through the cooling chamber toward the drying chamber.

2. A drying mechanism comprising a drying chamber, a cooling chamber associated therewith whereby particles may fall from the drying chamber into the cooling chamber, an apron in the drying chamber adjacent the bottom thereof, outlet 'breeching in the drying chamber under the apron, a belt in the cooling chamber to remove particles therefrom. and means to direct a cooling iluid against the belt to remove particles therefrom, the fluid subsequently being directed through the cooling chamber toward the drying chamber.

3. A drying mechanism comprising a drying chamber, a cooling chamber associated therewith whereby particles may fall from the drying chamber into the cooling chamber. a belt in the cooling chamber to remove particles therefrom. and means to direct a cooling iiuid against the belt to remove particles therefrom, the uid subsequently being directed through the cooling chamber toward the drying chamber.

WILLIAM SPENCER BOWEN'. JULIUS FREEMAN.

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