US3845704A

US3845704A - Air-blast grain huller

Info

Publication number: US3845704A
Application number: US00229028A
Authority: US
Inventors: V Vinogradov; Z Yanovskaya; V Bykov; A Sokolov; A Ivanoz; A Leikin; E Grinberg; Y Zhislin; A Krikunov
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-02-24
Filing date: 1972-02-24
Publication date: 1974-11-05
Anticipated expiration: 1991-11-05

Abstract

The air-blast grain huller consists of a mixing tube with a contractor at the entry of the unscoured grain into its channel, and a nozzle placed in the contractor to supply air into the tube. Mounted in the nozzle hole is a stem, one end thereof being disposed within the contractor. The channel of the mixing tube expands stepwise in the axial direction away from the nozzle, while in the places of passage from one step of the tube to another there are made ports for additional air injection into the channel.

Description

United States Patent 1 1 Zhislin et al.

[ Nov. 5, 1974 1 AIR-BLAST GRAIN HULLER [76] lnventors: Yakov Moiseevich Zhislin, 13

proezd Mariinoi .Roschi, 44/46, kv. 35; Alexandr Eliseevich Krikunov, prospekt Mira, 7, kv. 20; Alexandr Yakovlevich Sokolov, ulitsa Panfilova. 18a, kv. 30; Alexei llvanovich Ivanoz, Veernaya ulitsa, 3, korpus 6, kv. 77; Albert Yakovlevich Leikin, Trifonovskaya ulitsa, 54, kv. 193; Efim Naumovich Grinberg, proezd Nansena, 6, korpus 2, kv. 77; Vyacheslav Dmitrievich Vinogradov, ulitsa admirala Makarova, 21, kv. 58; Z inaida Solomonoyna Yanovskaya, ulitsa Garibaldi, 27, korpus 1, kv. 1 67; Valery Andreevich Bykov, Krasnogvardeisky bulvar, 7, kv. 11,

all of Moscow, USSR.

[22] Filed: Feb. 24, 1972 [21] Appl. No.: 229,028

[52] US. Cl 99/519, 99/614, 99/623 [51] Int. Cl 45c 39/00 [58] Field of Search 99/2338, 525, 600, 614, 99/623,519; l5/3.l3

[56] References Cited UNITED STATES PATENTS 18,177 9/1857 Ager .1 99/614 X 134,619 1/1873 Vandegrift 99/600 X 175,148 3/1876 Peabody 258,341 5/1882 Ager 775,098 11/1904 Welch.... 777,986 12/1904 Welch 2,759,511 8/1956 Jacobson 3,158,187 11/1964 Smith 15/313 X FOREIGN PATENTS OR APPLICATIONS 545,301 8/1957 Canada .l 99/525 505,898 9/1954 Canada 99/2338 622,103 4/1949 Great Britain 99/2338 1,188,089 4/1970 Great Britain 99/2338 Primary Examiner-Harvey C. Horhsby Attorney, Agent, or F irm-Waters, lRoditi, Schwartz & Nissen 1 1 ABSTRACT The air-blast grain huller consists of a mixing tube with a contractor at the entry of the unscoured grain into its channel, and a nozzle placed in the contractor to supply air into the tube. Mountedin the nozzle hole is a stem, one end thereof being disposed within the contractor.

The channel of the mixing tube expands stepwise in the axial direction away from the nozzle, while in the places of passage from one step of the tube to another there are made ports for additional air injection into the channel. 7 1

1 Claim, 1 Drawing Figure AIR-BLAST GRAIN HULLER The present invention relates to air-blast grain hullers employed in the groats, mixed feed, confectionery, and butter-and-fats industries, and can be most effectively utilized for hulling groats and filmy crops.

Known in the art are air-blast grain hulling devices, comprising a mixing tube disposed in a substantially vertical position and having a contractor at the entry of the unscoured grain into its channel, and a nozzle mounted in the tube contractor, through which nozzle air is fed.

In the known devices the nozzle is made with an open round outlet hole whose diameter is near to the grain size, which limits grain concentration in the air jet and, respectively, the productive capacity of the device, since the ratio of the jet perimeter, within which grain is injected, to the sectional area of the jet is relatively small.

Besides that, in the free space of the contractor between the nozzle and the entry of the mixing tube channel the grain is strongly stirred by the airjet, which results in the grain kernels being damaged. The inner channel in the middle part of the mixing tube in the known devices has a constant cross section along its length, thus limiting the possibilities of its elongation because of aerodynamic resistance and preventing complete utilization of the air jet energy for grain hulling. The design of the nozzle has no provisions for regulating the size of the nozzle outlet hole and the air jet cross section, which is necessary to optimize the conditions of the air-blast hulling process.

In the known devices the mixing tube is made in the form of a solid hollow element, thus requiring its complete replacement in case of a partial wear of the walls at the channel entry. What is more, the material of which the mixing tubes are made does not always secure sufficiently intense grain friction against the tube walls, which adversely affects the hulling efficiency, particularly for grains having a shell grown tight with the kernel, for example, barley grains. A significant current velocity at the exit from the mixing tube causes intense splitting of the kernels.

It is an object of the present invention to provide an air-blast huller, wherein the nozzle and the mixing tube would be made so as to raise the output of the huller through enhancing grain concentration in the air flow.

Another object of the present invention is to provide an air-blast huller, wherein grain splitting would be reduced.

A further object of the present invention is to provide an air-blast huller with maximum utilization of the air flow energy for the hulling process.

A still further object of the present invention is to provide an air-blast huller, wherein the hulling process would be swift.

With these and other objects in view, in an air-blast grain huller, comprising a mixing tube disposed in a substantially vertical position and having a contractor at the entry of the unscoured grain into its channel, and a nozzle mounted in the tube contractor, through which nozzle air is fed, according to the invention, placed in the hole of the nozzle coaxially therewith is a stem, one end of which is located within the contractor of the mixing tube, the channel of thelatter expanding stepwise in the axial direction away from the nozzle,

and ports being provided in the tube, in the passages between its steps, for additional air injection thereinto.

Due to the location of the stem in the nozzle the air 5 jet acquires a tubular shape, thus raising grain concentration in the jet, since as compared to a continuous jet section, a significant gain is achieved in the ratio of the outer perimeter of the injection jet to its cross-sectional area, and hence, in the ratio of the amount of injected grain to air consumption.

Location of one of the stem ends within the contractor of the mixing tube precludes strong stirring and splitting of grain therein, as the grains contacting the jet are retained by the stem and are entrained therealong into the channel of the mixing tube.

The stepwise expansion of the channel of the mixing tube reduces its aerodynamic resistance, which permits increasing its length and, accordingly, raising the utilization factor of the air jet energy, while the shock waves produced by the abrupt expansion of the air flow in the passages from one tube step to another intensify the hulling process.

The additional air injection through the holes in the passages from one step to another strengthens the shock waves, and also causes partial braking of the air flow by the new air masses involved thereinto.

Advantageously, the stem portion disposed in the nozzle and the contractor should be made narrowing in the axial direction from the nozzle toward the mixing tube channel, the stem itself being placed in the nozzle so as to be capable of adjustment displacements.

This makes possible regulating the dimensions of the nozzle outlet hole and the dimensions of the air jet cross section in accordance with the grain size and moisture and the strength of its shell, thus enabling the choice of optimum values of said dimensions to attain a maximum hulling effect.

Preferably, each step of the channel should be formed by a separate tube mounted so, that the outlet hole of the preceding tube is disposed in the contractor of the subsequent one, the tube itself being made as a series of hollow sleeves enclosed in a casing, and the holes for additional air injection into the channel being formed by these contractors and the lower edges of the tubes.

Assembling the mixing tube from separate tubes provides for fast dismantling of the device, and making each tube as a set of sleeves permits replacing the sleeves or changing their places with their wear, thus extending the life of the huller.

it is also advisable producing the sleeves from an abrasive material, and making the sleeves of each tube, starting from the second one, with holes of two different diameters in order to place them so as to form a stepped channel.

Such a design of the sleeves helps to intensify the hulling process, since it increases the grains friction against the inner walls of the channel and enhances the destructive effect of the air flow on: the grain shell due.

to the cyclic variation of the flow speed, density and pressure.

The exit hole of the mixing tube should preferably be grain huller with references to the appended drawing which is a schematic representation of the huller according to the invention shown in a longitudinal section.

Th air-blast grain huller comprises a chamber 1 terminating in a nozzle 2, and a mixing tube 3 with a channel 4 disposed in a substantially vertical position. Tube 3 is provided with a contractor 5 located at the entry of the unscoured grain into channel 4 (the direction of grain entry and exit being shown at A in the figure).

Chamber 1 is fitted with a socket 6 to feed therethrough compressed air which then issues through hole 7 of nozzle 2, the latter being located within contractor 5.

To increase the amount of injected grain, placed in hole 7 coaxially with nozzle 2 is a stem 8. Stem 8 is disposed in nozzle 2 so as to be capable of adjustment displacements, one end 9 of stem 8 being located within contractor 5 and made narrowing along axis 0--0 in the direction away from nozzle 2 toward channel 4 of tube 3, while the other end 10 is threaded and fitted with a hand-wheel 11 by which it is screwed into a hole made in chamber 1.

Channel 4 expands stepwise downward along axis 0-0. In the places of passage from a step B of channel 4 to another step C (the number of steps in this device can be chosen arbitrarily, only two being shown in the figure) there are provided ports 12 for additional air injection into the channel, the sectional area of channel 13 in step B being less than that of channel 14 in step C. Such a stepwise-expanding shape of channel 4 reduces its aerodynamic resistance and raises the utilization factor of the air jet energy.

Each step B and C of channel 4 is formed by

separate mixing tubes

15 and 16. These

tubes

15 and 16 are mounted so, that the end of the preceding tube 15 is located in a contractor 17 of the subsequent tube 16, the hole 12 being formed by this contractor 17 and the lower edge of the mixing tube.

Each

tube

15 and 16 is made as a series of sleeves l8 enclosed in a casing 19 and retained therein by a nut 20.

The mixing tube 16 forming the step C is assembled of

alternating sleeves

21 and 22 having holes of two different diameters D, and D respectively, the thus formed channel having a stepped shape.

Sleeves

21 and 22 are made of an abrasive material.

To reduce the speed of the hulled grain movement the exit hole of tube 16 is provided with a diffuser 23.

The grain huller operates as follows.

As grain is fed into contractor 5 in the direction shown by arrow A, and compressed air is supplied thorugh socket 6, air flows at a supersonic speed through the annular slit formed by hole 7 of nozzle 2 and the narrow end 9 of stem 8, the grain being thus injected from contractor 5 into channel 13 of tube 15 which is formed by the holes of sleeves 18. While the grain moves along stem 8 and tube 15 it is partially hulled by the effect of the impact of jets, the difference of pressures in the jet and under the grain shell, the in-, ertial loads on the grain, and friction of its shell against the walls of sleeves 18.

Due to the provision of stem 8 in the grain feeding zone the grains arriving at the air jet and having different directions and speeds do not impede each others entry into the jet, which permits raising grain concen tration in the air jet, and reducing grain stirring in contractor 5 and energy losses therein.

Issuing from channel 13 of tube 15 is a double-phase flow (air grain) which enters channel 14 of the other tube 16 mounted coaxially with the first one.

Owing to the abrupt change of the sectional area of channel 14 with respect to channel 13, as well as to the additional air injection into the flow through port 12, shock waves are produced which strip the grain shells, their strength and bond having been pre-weakened in channel 13 of tube 15.

On arrival at channel 14 of tube 16 the air flow in the course of its movement through the holes of

sleeves

21 and 22 is subject to cyclically alternating compression and expansion causing sharp cyclic oscillations, i.e., alternating drops and rises, of the air velocity, pressure, and density which repeatedly occur along channel 14.

Thus, the forces acting on the grain shells due to variation of said parameters (velocity, pressure, density) acquire a cyclic pulsed nature, which essentially intensities the hulling process, the shells being stripped even from such grains where they have grown tight with the kernel. The use of abrasive material for the'sleeves promotes friction of the grains against the walls of channel 14 in tube 16, which further intensities the hulling process.

As the double-phase flow moves along diffuser 23 it loses speed, thus precluding the splitting of the hulled grain.

What we claim is:

1. An air-blast grain huller, comprising: a chamber with means for supplying compressed air into said chamber; a nozzle communicating with said chamber and having an orifice for discharging air from said chamber and creating a stream of air for hulling grain; a mixing tube for hulling grain by said stream of air discharged from said nozzle, said tube being arranged substantially vertically under said chamber and having a channel with several sections of circular cross-sections arranged one above another, the diameter of a section below a higher section being greater than the diameter of said higher section; ports in said tube and located in the places of transition from one section of the channel to another for passing additional injected air into said channel; a funnel-shaped member in said mixing tube for feeding grain into said channel, said funnel-shaped member containing said nozzle; a stem arranged in the orifice of said nozzle and coaxial with the axis of said nozzle, one end of said stem being held in said chamber, and the other end of said stem projecting in said funnel-shaped member; each section of said channel being formed by a separate auxiliary tube with outlet hole mounted so that the outlet hole of the preceding tube is located within the following one, said ports for passing additional injected air into said channel being formed partially by the lower parts of the auxiliary tubes; each auxiliary tube comprising a series of sleeves enclosed in a casing; said sleeves being made of abrasive material; said sleeves of each auxiliary tube, starting from the second one, having holes of two different diameters and being installed alternately so that the diameter of the channel section jointly formed by them alternately grows and decreases stepwise in a downward direction.