DOUBLE-DRUM ROOT CROP WASHING MACHINE WITH CHAIN TRANSMISSION

ABSTRACT

The paper describes a double-drum root crop washing machine with a chain transmission, which was designed by the authors of this work and assembled for testing and operation in a mini-technical line for processing root crops. The authors calculated the chain transmission specifically for this design.

АННОТАЦИЯ

В работе приводится описание двухбарабанной моечной машины корнеплодов с цепной передачей, которая была спроектирована авторами настоящей работы и собрана для испытания и работы в мини технологической линии переработки корнеплодов. Авторами рассчитана цепная передача конкретно для данной конструкции.

Keywords: traffic flow, road congestion, density, traffic intensity.

Ключевые слова: транспортный поток, дорожный затор, плотность, интенсивность движения.  

Introduction. Currently, washing machines of various types and designs are used for washing food plant raw materials and sanitizing equipment. They are classified as follows: by the nature of the process (continuous and periodic); by the type of objects being processed (for washing raw materials); by the type of devices moving objects to be washed (linear and drum); and according to the method of exposure to the washing medium (syringe, soak-off, and soak-syringe).

Of the variety of washing machines, the most widely used are the paddle, belt, drum, vibration, combined, elevator, brush, etc.

The following requirements are imposed on washing machines: a high degree of cleanliness of the washed objects; the elimination of damage to raw materials or broken and deformed containers; minimal water and energy consumption; ease of manufacture and maintenance; high operational reliability; small overall dimensions and weight.

The choice of washing machine is determined by the structural, mechanical, and strength properties of plant raw materials, as well as the nature and number of contaminants on the surface of the raw materials.

Drum washing machines. Washing in drum washing machines is carried out by rotating the drum due to the intensive mixing of the raw materials and the impact of the falling raw materials on the surface of the water. The efficiency of the washing process is determined by the ratio of forces acting on the raw materials in the drum. At low drum speeds, the raw material is located in its lower part. With an increase in the number of drum revolutions, the angle of rise of the raw material increases (in smooth drums), and the higher the number of revolutions, the higher the rise, separation, and fall height of the raw material. As the lift angle increases, the efficiency of the washing process increases as a result of better mixing and a higher drop height of the raw materials. However, at a significant number of drum revolutions, a moment may come when the price.

Methodology. Preparing agricultural products by washing them before processing or storage is also an important procedure due to possible losses. Finding a modern, labile method is also a task of scientific research.

Washing vegetables and fruits is carried out on various types of machines, the main purpose of which is to remove soil, sand, and other foreign elements. When choosing the type of washing, you should take into account the type of raw materials, the conditions for growing the product, the type of land if these are root crops, as well as the productivity of the line to ensure the quality of the resulting product after washing.

The following requirements apply to washing machines:

• high degree of purity in washed objects,
• eliminating damage to raw materials or broken and deformed containers,
• minimal water and energy consumption,
• ease of manufacture and maintenance,
• high operational reliability,
• small overall dimensions and weight.

Machines for washing fruits, berries, and vegetables are divided into several types:

• bubbling washing: the raw material is completely immersed in a receiving bath of water, where air is supplied through holes in the tubes, creating the effect of boiling water;
• Immersion washing: scraper moving elements are installed in a receiving bath with water, which create the direction of movement of water and raw materials;
• Drum washing machines: raw materials are washed with water and friction of the product against the walls of the drum and the parts of the product themselves;
• brush washing machines—the product in them is cleaned with brushes mounted on shafts. These machines can be made in the following configurations: flat, drum, or bowl-shaped U-type.

Results and Discussion. In the course of course work and a master's thesis within the framework of applied research work carried out at the department of "Technology and Service of Agriculture" in 2012–2013, a double-drum washing machine for root crops was designed and built in 2013.

The double-drum root crop washing machine belongs to equipment for the food industry, namely to devices for washing fruit and vegetable products, mainly with a solid structure. By type of washing, the model refers to drum washing machines where washing is carried out by rubbing the raw materials and the walls of the drum against each other.

Main technical characteristics:

Drum length: 1250 mm; diameters of drums in the shape of truncated cones: large (90 and 75 cm); small (60 and 54 cm);

Design dimensions 1500x1200x1500mm

Productivity: 1-3 t/h;

Electric energy consumption: 2.2 kW/h; engine speed: 1000 rpm.

Water consumption at 0.3 MPa, m3/h 1.4; structure weight: 150 kg.

The designed machine has smaller dimensions and, accordingly, a lower a lower weight and cost. It is clear that the weight reduction was achieved due to the design of the two-cylindrical drum.

The quality of washing with relatively equal drum sizes and the speed of product movement through the drums of washing machines are improved by increasing the path of fruit passage during the washing process.

At the experimental base of Tashkent State Technical University, technological tests of a double-drum root crop washing machine of the proposed design were carried out with positive results.

Figure 1. Scheme of a washing machine for root vegetables:

1-root vegetables; 2-hopper loading; 3-line water supply; 4-outer cone drum; 5-inner cone drum; 6-support; 7-electric motor; 8-draining dirty water; 9-brushes; 10-water inlet neck; 11-helix; 12-pallet

Figure 2. Photo of a two-drum washing machine

As noted in the technical characteristics of the washing machine under study, the electric motor is three-phase (220V) with an engine speed of 1000 rpm.

Drum-type washers have an optimal speed of 0 to 10 to 20 rpm.

To basically reduce the speed of the electric motor, use a gearbox that reduces the speed by 30 times.

It was desirable to reduce the resulting torque of 35 revolutions per minute to 14–16 revolutions per minute, and therefore it was necessary to calculate the reduction by chain transmission.

In the washing machine transmission developed in the course project, a chain transmission is used to reduce the rotation speed of the transmission shaft.

The simplest and most common method is to use a single-row transmission roller chain (SR), which was adopted for this study (figure below).

Figure 3. Single-row roller chain: 1 connecting link; 2 transition links.

A simple chain transmission comes with two sprockets.

The main parameter of the chain is its step t; the remaining geometric parameters of the transmission are expressed depending on the pitch:

Recommended optimal center distance

sprocket pitch diameter

d _d =

where z is the number of teeth in the chain transmission.

stars; D_e1 and D_e2—outer diameters of sprockets, determined according to GOST 592-81:

Let's take the initial data. Transmitted power P = 2.2 kW.

The rotation speed of the driving sprocket n 1 is 35 rpm, and the and the transmission sprocket n 2 is 16 rpm.

The angle between the center lines and the horizontal is 450; periodic lubrication is done in one shift.

We select a single-row roller chain (diagram, Fig. 1) from GOST [1] and determine the pitch using formula (5).

where T _{1= = =} 660.5kK _e = 1.625.

Number of transmission teeth

 z ₁ = 31-2 u =31- 2 =29

slave z ₂ = z ₁ u = =54

the average value [p] according to table 7.18 from the reference book [1]. [p] = 20 MPa, number of chain rows: n = 1.

= 30.4

According to table 7.15[1] according to GOST 13568-75, we take the nearest large value t = 31.75 mm;

Determine the number of chain links L_t, and first find the total number of teeth.

z _z = z ₁ + z ₂ = 29+54=83

Amendment d = = =4.0

a = 40 t ; = =40.

According to the formula

L_t = 2 a_t + 0.5 z_z + = =121.9

Round to a whole number L_t =122

We clarify the center distance using the formula a = 0.25 t.

= 0.2 = 1217 mm

Determine the pitch diameters of the sprockets, leading [1, 2].

d _{d 1} = = = 284.11mm

slave d _{d 2} = =533.3mm

External diameters

D _e = t (K _z +0.7) – 0.31 d ₁

where K _z = ctg ;

 d ₁ – roller diameter

D _e1 =30.4 (ctg +0.7) - 0.3 = 320.1 mm

D _e2 =30.4 (ctg +0.7) - 0.3 = 554.2 mm

Table 1.

 Final table - main quantities

K _e is a coefficient that takes into account the installation and operation conditions of the chain transmission.

K _e = k _l k _a k _n k _r k _cm k _p

Considering that the operation of the washing machine takes place under a quiet load, we take k _l = 1, with an interaxial distance of less than 50 cm, k _{a =} 1, k _p = 1.25 with manual chain adjustment, k _cm = 1.3 with periodic lubrication, k _p = 1 with single-shift work, and k_{n =} 1 when the chain is tilted up to 60 ⁰ to the horizon.

Total K _e =1.25x1.3= 1.625

Conclusion. Thus, the calculated chain transmission was used in a double-drum root crop washing machine, which has advantages over analogs [3, 4]:

• The efficiency of washing raw materials has been additionally increased by increasing the path of passage of fruits and, accordingly, increasing the time of contact interaction of fruits with washing elements.
• The designed machine has smaller dimensions and, accordingly, a lower a lower weight and cost. (1500x1200x1500mm, 150 kg, 5 million sums)
• The proposed machine can operate both autonomously and as part of a continuous mini-production line.

References:

1. Kursovoe proektirovanie detaley mashin. pod red. Chernavskogo S.A. 2.ye izd. M.: Mashinostroenie.1987. – 416 s. [in Russian]
2. Obshetexnicheskiy spravochnik, pod red. Skoroxodova Ye.A., 2.ye izd. M.: Mashinostroenie. 1982. - 415 s. [in Russian]
3. Canning solutions and food processing equipment. "BESTEQ-Engineering" [Electronic resource]. – Access mode: https://en.besteq.ru/
4. Complex solutions for food enterprises. "Innovation technological solutions" [Electronic resource]. – Access mode: https://itsodessa.com/eng
5. Zayavka na izobretenie Dvuxbarabannaya moechnaya mashina korneplodov. FAP 2014 0016. 17.02.2014 g. Norkulova K.T., Umarov V.F., Mamatkulov M.M. [in Russian]