RU2567315C2 - Mixer-fermenter - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to mixing and fermenting of loose materials for production of fodder with high content of protein from inferior products. Mixer-fermenter consists of the bin installed at the frame, loading opening and discharge pipe, discharge screw, shutter, working tool, motor, reduction gearbox, control board and constant temperature control system. The latter comprises heating element, layer of heat insulation, temperature gages and relays built in control board. Working tool consists of the shaft, outer and inner ribbon feeders and scrapers secured to the shaft by rods. Scrapers are composed of spiral turn with pitch equal to half the length L on the bin inside and diameter equal to bin ID D. Outer ribbon feeder with turn height h features diameter 3/4D and pitch 1/6L while inner one features turn height 3/2h, diameter 2/5D and pitch 1/4L. Screw turns are arranged at the angle smaller angle φ of natural slope of mixed material.

EFFECT: lower specific power costs, higher process efficiency, better quality of mixing, intensified heat exchange, enhanced performances.

2 dwg

Description

The invention relates to equipment for mixing bulk materials and fermenting feeds, can be used in agricultural production on livestock complexes and farms in lines for the preparation of feeds with a high content of proteins from low-value products.

A screw mixer is known for processing materials, mainly bulk, containing a housing, a screw located inside it, the shaft of which is hollow and has radial holes in the inter-turn space with integrated rods, at the ends of which elements of a tape spiral are fixed with the direction of winding in the opposite direction to the screw winding, when this, in each inter-turn space, there are three elements with heights of 1 / 4h, 1 / 2h and 3 / 4h, respectively, where h is the height of the screw turn, and the elements of the tape spiral are installed with possible awn changing the angle between the axis of the element and the axis of rotation of the screw shaft in the range 0 ... 180 ° [1].

The disadvantage of the mixer is the low efficiency of the process of mixing bulk mixtures due to their movement during the process in only one direction.

This device is characterized by high specific energy consumption due to the use of a screw with integrated rods having elements of a tape spiral with the direction of winding in the opposite direction of winding of the screw.

In addition, the design and process of the screw mixer are not suitable for the fermentation of bulk materials with a liquid phase of various viscosities.

The closest in technical solution and the achieved result to the present invention relates to a mixer for mixing bulk materials, consisting of a hopper mounted on the frame, loading and unloading nozzles, shutter, combined auger, motor, gearbox, working body, which is a combined auger, consisting of a shaft on which rods with elements of a tape spiral and belt screws located along a helical line through 90 ° are installed: external with a diameter D and pitch L; medium with a diameter of 3 / 4D and pitch 3 / 4L; internal with a diameter of 2 / 5D and pitch 2.5L [2] - prototype.

The disadvantage of this invention is the impossibility of mixing the wet components of the materials loaded into the hopper and, as a result, sticking of the mixed materials onto the walls of the hopper and, accordingly, the formation of stagnant zones, causing deterioration of the material mixing process and incomplete unloading of the finished feed.

The use in this device of a working body equipped with rods with elements of a tape spiral and three tape augers without taking into account the installation angles of their turns significantly increases the energy consumption of the process of mixing the components loaded into the hopper materials.

Another disadvantage of this device is the impossibility of its use to obtain fermented feed - the most valuable, easily digestible and healthy food feed for farm animals.

In addition, the functionality of the use of this mixer is limited due to its use for the preparation of feed only in the stationary version.

The essence of the invention lies in the fact that the well-known mixer-fermenter, consisting of a hopper mounted on the frame, a loading window and an unloading pipe, damper, motor, gearbox, working body, which is a combined screw, consisting of a shaft, on which the rods are mounted and tape external and internal augers, rods have scrapers made in the form of a spiral coil with a step equal to half the length L of the inner space of the hopper, and a diameter equal to the inner diameter D of the hopper, and in the external tape auger with a height of turns h made of diameter 3 / 4D and a pitch of 1 / 6L, internal with a height of turns 3 / 2h - diameter of 2 / 5D and a step of 1 / 4L, and the turns of screws made at an angle less than the angle φ of the natural slope of the mixed material Moreover, the hopper equipped with an unloading screw is equipped with a heating element having sensors and temperature switches, the recording elements of which are mounted on the control panel.

As a result of the analysis of literary sources, no identical execution of the proposed device was found. Moreover, distinctive features from the prototype signs give the claimed combination of new properties, manifested in a positive effect.

When making scrapers in the form of a spiral coil with a step equal to half the length L of the inner space of the hopper, and an external tape screw with a height of turns h of diameter 3 / 4D and a step of 1 / 6L, internal with a height of turns of 3 / 2h with a diameter of 2 / 5D and step 1 / 4L provides the movement of the same volume of material by each element in its direction for one revolution of the shaft. Scrapers move the material from the center of the hopper to its side walls, the external screw - from the side walls to the center of the hopper, and the internal screw - from the center to the side walls of the hopper. As a result of this, the formation of stagnant zones is excluded, the components of the material loaded into the hopper are intensively mixed, thereby increasing the efficiency of the process and the quality of mixing.

The implementation of the turns of the screws at an angle less than the angle φ of the natural slope of the mixed material, due to the reduction of friction between the turns of the screws and the material, reduces the specific energy consumption during the process.

The equipment of the rods with scrapers with a diameter equal to the inner diameter D of the hopper helps to intensify the heat transfer of the walls of the hopper with the heated material by removing sticky moist food from the walls. This circumstance also leads to a decrease in specific energy consumption in the production of fermented feed.

Equipping the hopper with an unloading auger provides a reduction in the unloading time of the finished fermented feed, expands the functionality of the mixer-fermenter in addition to the stationary version, also as a mobile feed dispenser with unloading it into the animal feeders.

The equipment of the bunker with a heating element allows accelerating the development of bacteria in it by transferring heat to the mixed components of the material, which reduces the time for obtaining fermented feed.

The presence of temperature sensors and relay elements in the heating element, the recording elements of which are mounted on the control panel, allow automatic maintenance of the necessary constant temperature of the nutrient medium to obtain high-quality fermented feed.

As a result, during the operation of the proposed device, a positive effect is achieved that exceeds the effect of the prototype. A new set of features of the claimed device, providing a positive effect, has significant differences.

The figure 1 presents a General view of the mixer-fermenter, figure 2 - General view of the mixer mixer-fermenter.

The mixer-fermenter consists of a hopper 1 mounted on the frame 2, a loading window 3 and an unloading pipe 4, an unloading screw 5, a shutter 6, a working body 7, an electric motor 8, a reducer 9, a control panel 10, and a constant temperature maintenance system, which includes a heating element 11 (for example, a heat tape or a copper coil with a coolant), a thermal insulation layer 12, temperature sensors 13 and a temperature switch, the recording elements of which are mounted on the control panel 10.

The working body of the mixer-fermenter consists of a shaft 14, internal 15 and external 16 belt augers, scrapers 17, which are attached to the shaft 14 using rods 18. The scrapers 17 are made in the form of a spiral coil with a step equal to half the length L of the inner space of the hopper 1, and a diameter equal to the inner diameter D of the hopper 1. The outer tape auger 16 with a height of turns h is made with a diameter of 3 / 4D and a pitch of 1 / 6L, and the inner screw 15 with a height of turns of 3 / 2h is made with a diameter of 2 / 5D and a step of 1 / 4L. The turns of the screws 15 and 16 are made at an angle smaller than the angle φ of the natural slope of the mixed material.

Mixer-fermenter works as follows.

Through the loading window 3, pre-crushed material is loaded (for example, straw), Lesnov’s prepared primary sourdough is added and poured with hot water (temperature 48 ... 80 ° C) in a 1: 1 ratio (the resulting mixture is called a nutrient medium). On the control panel 10 set the switches in the mixing mode and turn on the mixer. After the primary starter culture is evenly distributed in the entire volume of the material loaded into the hopper 1, the mixing is stopped and the switches on the control panel 10 are set to fermentation mode. In this mode, the automatic system for maintaining a constant temperature of the nutrient medium is turned on (since bacteria develop faster, accelerating the fermentation process at a certain temperature of the nutrient medium), and the working element 7 starts to rotate at a very low frequency (about 1 min ^-1 ). In the fermentation mode, the mixer operates until a fully prepared fermented feed is obtained. In the fermentation process due to the rotation of the working body 7, the material is mixed and the temperature of the nutrient medium is equalized in the entire volume. Scrapers 17 in addition to moving the material from the center to the side walls of the hopper 1 cleans the cylindrical surface of the hopper 1, thereby intensifying the heat transfer process in the nutrient medium. After fermentation, the finished product is discharged through the discharge pipe 4 using the discharge screw 5, after opening the shutter 6. The mixer-fermenter can be performed on a mobile platform. In this case, it can be used as a distributor with feed unloading using the unloading auger 5 into the animal feeders.

The advantage of the invention in comparison with the prototype is to reduce specific energy consumption and increase the efficiency of the process of obtaining fermented feed by improving the quality of mixing and intensification of heat transfer between the walls of the hopper and the nutrient medium, expanding the functionality of the use as a mobile dispenser of fermented feed with a decrease in the time of its unloading.

This is confirmed by the following calculations.

The energy costs required to drive the shaft for the working body of the mixer-fermenter are determined by the expression:

where Q is the performance of the tape screw screw of the mixer, t / h;

υ is the axial velocity of the material, m / s;

g is the acceleration of gravity, m ² / s;

F _k - the friction force of the material on the inner surface of the walls of the mixer-fermenter, N;

P ₀ ′ —moving force tangent to a circle passing through the center of pressure of the load, N;

D ₀ - the diameter of the circle passing through the center of the pressure of the load on the surface of the screw, m;

ω is the angular velocity of the screw, s ^-1 ;

ω ₂ is the angular velocity of the mixed material, s ^-1 ;

P ₀ ″ - circumferential force on the outer edge of the screw of the screw, N;

D is the diameter of the outer edge of the screw, m;

k ₀ - coefficient taking into account jamming and crushing of the cargo;

η _n - the efficiency of the bearings of the screw shaft.

The axial velocity of the material is found by the formula:

where d is the diameter of the inner edge of the screw, m;

n is the number of revolutions of the screw, min ^-1 ;

β is the angle of inclination of the axis of the screw to the horizon, deg;

φ ₀ is the specific gravity of the material, t / m ³ ;

with ₀ - coefficient taking into account the leakage of material between the housing, material and the screw surface.

The friction force of the material on the inner surface of the walls of the mixer-fermenter is calculated by the expression:

where f ₂ is the coefficient of friction of the material on the steel surface of the body during movement;

P _c - centrifugal force, N.

G is the weight of the material, N;

φ ′ is the angle of rotation of the material layer in the direction of rotation of the screw, deg.

The centrifugal force, weight of the material and the angle of rotation of the layer of material is determined by the formulas:

where α is the angle of elevation of the helical thread of the screw along the outer edge, deg;

ρ ₁ - the angle of friction of the material on the steel surface of the screw in motion, deg.

where S is the screw pitch, m

where f ₁ is the coefficient of friction of the material on the steel surface of the screw during movement.

The driving force tangent to the circle and the circumferential force on the outer edge of the screw of the screw are determined by the expressions:

where α ₀ is the angle of elevation of the helix passing through the center of pressure of the material on the surface of the screw, deg.

θ is the angle of elevation of the helix along which the material point moves, degrees.

Using the obtained analytical expressions, the energy costs for the drive of the mixing body of the prototype and the proposed mixer-fermenter are calculated. The calculation results are presented in table 1.

When calculating the accepted: the specific gravity of the grain dermat φ ₀ = 0.7 t / h; the length of the shaft of the working body of the mixer l = 1.8 m; time for which it is necessary to obtain a quality mixture t = 5 min; the number of cycles that will allow you to effectively mix the material N = 3; load factor γ ₁ = 0.75; shaft rotation frequency n = 25 min ^-1 ; the angle of inclination of the axis of the mixer shaft to the horizon β = 0 °; coefficient allowing leakage between the housing material, the material and the screw surface C ₀ = 0.9; the coefficient of friction of the material on the steel surface of the screw when moving f ₁ = 0.44; the coefficient of friction of the material on the steel surface of the body during movement f ₂ = 0.44; the angle of elevation of the helix along which the material point for the horizontal screw moves without material rotation around the mixer shaft θ = 90 °; the angular velocity of the material ω ₂ = 0 s ^-1 ; coefficient taking into account jamming and crushing of the load, k ₀ = 1.25 for the external screw, k ₀ = 1.0 for the middle and internal screws; coefficient of performance for bearings η _P = 0.98.

As can be seen from the table, when performing tape augers: external with a diameter D and pitch L, medium with a diameter of 3 / 4D and pitch 3 / 4L, internal with a diameter of 2 / 5D and pitch 2.5L (as in the prototype), the rated power at the drive of the mixing organ is 11.3 kW. And when performing scrapers as in the proposed embodiment of the mixer-fermenter, i.e. in the form of a spiral coil with a step equal to half the length L of the inner space of the hopper, and an external tape screw with a coil height h with a diameter of 3 / 4D and a pitch of 1 / 6L, an internal one with a coil height of 3 / 2h with a diameter of 2 / 5D and a pitch of 1 / 4L, the calculated power for the drive of the mixing body is 9.1 kW, which is 24% lower than that of the prototype.

Literature

1. Screw mixer for processing materials, mainly bulk: patent No. 2103055 Ros. Federation, IPC B01F 7/08, A22C 5/00 / M.G. Shuvaev, I.A. Dubkov, Z.K. Galiakberov; applicant and patent holder Shuvaev Maxim Gennadevich. - No. 96110328/13; declared 05/22/1996; publ. 01/27/1998, Bull. Number 14. - 6 p.

2. Mixer: patent No. 2488434 Ros. Federation, IPC B01F 7/08 / P.A. Savinykh, N.V. Turubanov, V. Romanyuk, A.S. Kiselev, N.A. Chernyatiev; Applicant and patent holder State Scientific Institution Zonal Research Institute of Agriculture of the North-East named after N.V. Rudnitsky Russian Academy of Agricultural Sciences (RU), Technological and Natural Institute (PL). - No. 20121049220/05; declared 02/13/2012; publ. 07/27/2013, Bull. No. 21. - 7 p. - prototype.

Claims (1)

The mixer-fermenter, consisting of a hopper mounted on the frame, a loading window and an unloading nozzle, a shutter, an engine, a gearbox, a working body, which is a combined screw, consisting of a shaft on which rods and tape external and internal screws are installed, characterized in that the rods have scrapers made in the form of a spiral coil with a step equal to half the length L of the inner space of the hopper and a diameter equal to the inner diameter D of the hopper, and the outer tape auger with a height of turns h is made di 3 / 4D meter and step 1 / 6L, internal with a height of turns 3 / 2h - diameter 2 / 5D and step 1 / 4L, and the turns of the screws are made at an angle less than the angle φ of the natural slope of the mixed material, while the hopper is equipped with a discharge screw , equipped with a heating element having sensors and temperature switches, the recording elements of which are mounted on the control panel.

Images