RU212140U1 - drum dryer - Google Patents

Abstract

и внутренний барабан, установленный под углом конусности

противоположным углу наклона наружного барабана, и выполненный в виде конической обечайки, опорами которого служат пружины, равномерно распределенные по периметру и по длине, причем опоры выполнены из конических пружин переменной жесткости, частота колебаний которых, и максимальная, и минимальная жесткость пружин определяется в соответствии с выражениями, указанными в формуле полезной модели. Техническим результатом является увеличение производительности. 1 ил.

The utility model relates to apparatus for drying dispersed materials, namely, two-way drum dryers, and can be used in chemical, petrochemical, mining, construction, metallurgical, food, pharmacological, road and other industries, as well as in environmental processing and disposal processes solid and solid waste. The drum dryer contains an outer drum located at an angle of inclination to the horizon.

and an inner drum mounted at a taper angle

opposite to the angle of inclination of the outer drum, and made in the form of a conical shell, the supports of which are springs uniformly distributed along the perimeter and along the length, and the supports are made of conical springs of variable stiffness, the oscillation frequency of which, and the maximum and minimum spring stiffness is determined in accordance with expressions specified in the formula of the utility model. The technical result is an increase in productivity. 1 ill.

Description

The proposed technical solution relates to devices for drying dispersed materials, namely to two-way drum dryers, and can be used in chemical, petrochemical, mining, construction, metallurgical, food, pharmacological, road and other industries, as well as in environmental processing and disposal of solid and solid waste.

Known design of a two-way drum dryer, consisting of two drums - inner and outer. The inner drum consists of three parts connected by bolts. To compensate for thermal expansion, gaskets are supplied at the joints. Both drums are equipped with a lifting-vane inner nozzle. Wet material from the feeder enters the inner drum, from where the gaseous drying agent is also supplied, heated to 700°C. Further, the material and the heat carrier move in cocurrent and enter the outer drum, where the cocurrent pattern of their movement is also preserved. The dried material from the outer drum is poured into the chamber located on the side of the hot head of the inner drum and removed from the dryer. Gases from the chamber are sent for cleaning in cyclones (Lykov M.V. Drying in the chemical industry. - M.: Chemistry, 1970, p. 189).

The reasons hindering the achievement of the desired technical result include the complexity of the design and the possibility of particles sticking to the surface of the inner drum, which will lead to a decrease in the time of non-stop operation of the apparatus, and, consequently, to a decrease in the productivity of the dried material.

Known design drum dryer with two coaxially arranged horizontal drums. The stationary inner drum has a feeder for feeding wet material and communicates with the firebox from which high-temperature flue gases flow. Drying in the inner drum takes place in a suspended state with the direct-flow movement of the material and the drying agent. The end of the outer rotating drum from the point side is isolated from it and enters the discharge manifold, which is connected to the cyclones by a fan. On the other hand, the rotating drum enters the fixed chamber and seals at the junction against its walls. At the bottom of this chamber, there is a rotating rotor that swirls and grinds particles that come from an internal fixed drum. The supply of material from the stationary chamber to the outer rotating drum is controlled by valves. The dryer has a coolant suction system. It is also possible to supply fresh drying agent through the bypass pipe directly into the fixed chamber (US Pat. Germany 976224, class 82a, 39, 1961).

The disadvantages of the design include the complexity and low reliability of the nodes for grinding the material and its dosage into the outer drum, which can lead to an increase in pieces of material, and, consequently, a decrease in non-stop operation time and productivity.

Known design drum dryer. The closest technical solution in terms of the set of features, and adopted as a prototype, is the design of a drum dryer, mainly for dispersed and granular materials, containing two coaxially located rotating drums, a furnace and a heat carrier suction system, where both drums are connected in parallel to the furnace, and the heat carrier suction system for each of them it is autonomous, and the inner drum is made in the form of cylindrical shells of various diameters, having a telescopic connection and installed with the possibility of axial movement, and the inner of adjacent shells has a sharp edge (AS USSR No. 775564 F 26 B 11/4 , 1980)

The reasons hindering the achievement of the desired technical result include the fact that the execution of the inner drum from shells of different diameters, connected telescopically, leads to the formation of stagnant zones at the junctions, sticking of the material, and the possibility of sticking of the material to the inner surface of the outer pipe, which together will lead to a decrease in the time of non-stop operation, a decrease in the productivity of the dried material, and, consequently, the overall productivity of the device.

а внутренний барабан, установленный под углом конусности

противоположным углу наклона наружного барабана, выполнен в виде конической обечайки, опорами которого служат цилиндрические пружины, равномерно распределенные по периметру и по длине (ПМ РФ 205 150, F 26 B 11/4, 2021 г.).The closest technical solution in terms of the set of features, and adopted as a prototype, is the design of a drum dryer containing two rotating drums attached to a furnace, where the outer drum is located at an angle of inclination to the horizon

and the inner drum, mounted at an angle of taper

opposite to the angle of inclination of the outer drum, made in the form of a conical shell, the supports of which are cylindrical springs, evenly distributed along the perimeter and along the length (PM RF 205 150, F 26 B 11/4, 2021).

The reason preventing the achievement of the desired technical result is the insufficient intensity of heat and mass transfer from the drying agent to the particles of the dried material in the inner drum. This reduces the main operating time, and hence productivity.

The technical result of the proposed design of the drum dryer is an increase in productivity.

и внутренний барабан, установленный под углом конусности

противоположным углу наклона наружного барабана, который выполнен в виде конической обечайки, опорами которого служат пружины, равномерно распределенные по периметру и по длине, причем опоры выполнены из конических пружин переменной жесткости, частота колебаний которых определяется выражением:The set technical result is achieved by the fact that the drum dryer containing the outer drum, located at an angle of inclination to the horizon

and an inner drum mounted at a taper angle

opposite to the angle of inclination of the outer drum, which is made in the form of a conical shell, the supports of which are springs uniformly distributed along the perimeter and along the length, and the supports are made of conical springs of variable stiffness, the oscillation frequency of which is determined by the expression:

- частота колебаний конических пружин, Гц;where

- oscillation frequency of conical springs, Hz;

k – minimum spring stiffness, N/m;

M is the mass of the inner drum, kg;

n is the number of conical springs;

the maximum and minimum spring constant is determined by the following relationship:

where K and k are the maximum and minimum stiffness of the conical spring, respectively, N/m;

M and m are, respectively, the mass of the inner drum without the material to be dried and the mass of the material to be dried, kg.

Mounting the inner drum on supports made of conical springs of variable stiffness, the natural oscillation frequency of which is determined by expression (1), makes it possible to increase the amplitude of resonant oscillations, which will ultimately lead to an increase in productivity.

The maximum stiffness of the spring is determined by the proportion (2). Then the natural oscillation frequency of the empty inner drum as a physical pendulum is determined according to expression (1) and with the material being dried:

When proportion (2) is fulfilled:

and for any mass of material to be dried in the inner drum, its natural oscillation frequency as a spring pendulum is equal to the oscillation frequency of the empty drum and the forced oscillation frequency, which leads to oscillations in the resonant mode, which intensifies the process of heat and mass transfer, and hence productivity.

The drawing shows a diagram of the proposed design of the drum dryer.

и внутренний барабан 4, выполненный в виде конической обечайки, установленный под углом конусности

противоположным углу наклона наружного барабана, систему лотков 5 для перегрузки материала из внешнего барабана во внутренний, опоры 6, выполненные из конических пружин, максимальная и минимальная жесткость которых определяется выражением (2), переменной жесткости, собственная частота колебаний которых определяется выражением (1), равномерно распределенных по периметру и по длине, устройство загрузки влажного материала 7, патрубок для выгрузки готового продукта 8 и отвода отработанного сушильного агента 9.The drum dryer contains a blow fan 1, a furnace 2, an outer drum 3, located at an angle of inclination to the horizon

and the inner drum 4, made in the form of a conical shell, mounted at an angle of taper

the opposite angle of inclination of the outer drum, a system of trays 5 for transferring material from the outer drum to the inner one, supports 6 made of conical springs, the maximum and minimum stiffness of which is determined by expression (2), variable stiffness, the natural oscillation frequency of which is determined by expression (1), evenly distributed along the perimeter and along the length, a device for loading wet material 7, a pipe for unloading the finished product 8 and draining the spent drying agent 9.

The drum dryer works as follows.

The drying agent from the furnace 2 through the open ends enters in parallel into both rotating drums 3 and 4. Wet material is fed into the outer drum 3 by the loading device 7 and is dried to a free-flowing state in countercurrent mode. The material is loaded into the inner drum 4 with the help of trays 5. In it, the material particles come into a suspended state due to oscillations created by the supports 6, made of conical springs, the maximum and minimum stiffness of which is determined by expression (2), variable stiffness, the natural oscillation frequency of which is determined by expression (1), with a gentle mode. The finished product is unloaded through pipe 8, and the spent drying agent is discharged through pipe 9.

Example. Let the mass of the empty inner drum 4 be M=20 kg, and the mass of the material to be dried fed into it, m=50 kg. The total maximum mass of the inner drum 4 with the material to be dried:

M + m \u003d 70 kg.

We assume that the length of the drying agent supply pipe is 2.2 m, then the forced oscillation frequency created by the air flow will be determined by the expression (Yavorsky V.M., Detlaf A.A. Handbook of physics for engineers and university students. - M .: State publishing house of physical and mathematical literature, 1963. - p. 510):

– частота колебаний воздуха на входе в барабан, Гц;where

is the frequency of air oscillations at the drum inlet, Hz;

C is the speed of sound in the air flow, m/s;

d is the diameter of the classifying grid, m.

Then, at the speed of sound in the air stream, at a temperature of 100 ^° C, equal to 387.1 m / s, the frequency of forced oscillations will be:

.

.

Н/м. Тогда максимальное значение жесткости каждой пружины определяется в виде:The minimum value of the stiffness of each support 6, made of conical springs of variable stiffness, is taken

N/m. Then the maximum value of the stiffness of each spring is determined as:

.

.

Then the number of supports 6, made of conical springs of variable stiffness, is determined by the expression:

i.e. springs with variable stiffness from

при числе опор 6, выполненных из конических пружин переменной жесткости, равному 16, равномерно распределенных по длине в четырех проекциях.should oscillate with a frequency

when the number of supports is 6, made of conical springs of variable stiffness, equal to 16, evenly distributed along the length in four projections.

Thus, the fastening of the inner drum 4 on supports 6 made of conical springs of variable stiffness, evenly distributed along the length and along the perimeter, increases the amplitude of resonant oscillations between the drying agent and the material being dried, intensifies heat and mass transfer, which in turn increases productivity.

Claims (10)

Drum dryer containing an outer drum located at an angle of inclination to the horizon

, and an inner drum mounted at an angle of taper

opposite to the angle of inclination of the outer drum, made in the form of a conical shell, the supports of which are springs uniformly distributed along the perimeter and along the length, characterized in that the supports are made of conical springs of variable stiffness, the oscillation frequency of which is determined by the expression:

where

- oscillation frequency of conical springs, Hz, k – minimum spring stiffness, N/m; M is the mass of the inner drum, kg; n is the number of conical springs; The maximum and minimum spring constants are determined by the following relationship:

where K and k are the maximum and minimum stiffness of the conical spring, respectively, N/m; M and m are, respectively, the mass of the inner drum without the material to be dried and the mass of the material to be dried, kg.

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