RU64413U1 - LABORATORY INSTALLATION FOR STUDYING HEAT AND MASS TRANSFER WHEN EVAPORATING WATER INTO AIR FLOW - Google Patents

Abstract

The utility model relates to installations for conducting training sessions in the disciplines "Heat and Mass Transfer" and "Heat Engineering".

The objective of the utility model is to increase the accuracy of measuring the temperature of the flow, providing the conditions for adiabatic humidification of the air, and piloting the process of heat and mass transfer between water and air flow.

The objective is achieved in that a laboratory installation for studying heat and mass transfer during water evaporation into an air stream, containing a tube-shaped housing, an electric heater, a wattmeter, flow mixers, thermocouples, in which the case is curved, an electric heater is installed in the vertical lower part, in the inclined upper part of the case an elongated test section was mounted in the form of a glass tube wrapped on the outside with a damp cloth; the test section is fixed in the housing with needle supports having rubber at the ends beads to prevent slipping, to remove excess water used fabric tape, airflow mixers are in the form of washers with holes in the center. 5 s., 1 ill.

Description

The utility model relates to installations for conducting training sessions in the disciplines "Heat and Mass Transfer" and "Heat Engineering".

A well-known laboratory plant for heat transfer (FIPS, reg. No. 2006138755 dated 02.11.2006), containing a housing, an electric heater, nozzles for the outlet of heated air, in which the vertical cylindrical housing is made of brass, contains two pipes of the type "pipe in pipe", the inner the pipe, open on both sides, contains an electric heater connected to an external wattmeter and LATR, and two flow mixers, the outer pipe is open at the top and in the lower part has a conical shape with an outlet pipe, mounted outside the outer pipe with a sludge containing water with melting ice and a pipe for draining the water.

Closest to a utility model in technical essence is a patent ı2126175,

MKI G09B 23/16, publ. 10/02/1999 g. No. 4), which is additionally equipped with a humidifier, water vessels, flow mixers, an autotransformer and a wattmeter, while an electric heater is installed as a heater, the casing is made in the form of a vertically mounted pipe in which an electric heater and a humidifier are mounted, on the casing from its outer surface thermal insulation is applied, flow mixers are installed behind the heater and behind the humidifier, and a valve designed to measure the flow rate is installed in the outlet section of the housing, taken for the prototype. The disadvantage of the installation is the small surface of the evaporation of water into the air stream.

The objective of the utility model is to increase the accuracy of measuring the temperature of the flow, providing the conditions for adiabatic humidification of the air, and piloting the process of heat and mass transfer between water and air flow.

Laboratory installation for studying heat and mass transfer during the evaporation of water into an air stream, containing a tube-shaped housing, an electric heater, a wattmeter, flow mixers, thermocouples, the housing is curved, an electric heater is installed in the vertical lower part, and an elongated experimental section is mounted in the inclined upper part of the housing in the form of a glass tube wrapped on the outside with a damp cloth, the experimental section is fixed in the housing with needle supports having rubber balls at the ends to prevent slip, a cloth tape is used to remove excess water, air flow mixers are made in the form of washers with holes in the center.

This laboratory installation, due to the curved housing, allows better water drainage, and the experimental section in the form of a glass tube mounted on the housing and the execution of washers with holes in the center significantly increases the accuracy of measuring the flow temperature.

Figure 1 shows the described installation, figure 2 presents the processes in moist air in the diagram h-d (1-2 air heating, 2-3 - air humidification).

The housing 1 of the installation is made of a curved glass tube. In the lower vertical section, an electric heater 2 is mounted, the power of which is set using the LATR 3 and is controlled by a power meter 4. Behind the electric heater 2 is a flow mixer 5 made of thin glass fiber in the form of a washer with a hole. The flow mixer 5 is designed to equalize the air temperature t ₂ before measuring with a thermocouple 6 (figure 2). The thermocouple is introduced in the center of the stream through the pipe 7.

On the axis of the inclined part of the housing 1, an experimental section 8 is installed in the form of a glass tube 9, wrapped on the outside with a moist cotton cloth. The experimental section 8 is fixed in the housing 1 by needle supports 10 having rubber balls at the ends to prevent slipping of the experimental section 8. The matter is moistened with water from the vessel 11 through a rubber tube passed through the pipe 12. Excess water from the experimental section 8 is removed through the fabric tape 13 passed through the pipe 14 into the vessel 15.

Behind the experimental section 8, a flow mixer 16 is installed. After it, the temperature of the dry thermometer t _{3 with} thermocouple 17 introduced into the stream through the pipe 18 is measured and the temperature of the wet thermometer t _{3m with} thermocouple 19 installed through the pipe 20.

On the outside, the installation is covered with a layer of thermal insulation 16.

Air flow is determined by the speed of the outgoing stream, measured by an electronic anemometer.

Installation works as follows. The material in the experimental section 8 is moistened with water from the vessel 11. Then, the electric heater 2 is turned on to the network, setting the required power using the LATR 3 and the wattmeter 4. Thermocouple 17 control the onset of the stationary

mode in which the thermocouple readings remain constant in time. After reaching the stationary mode, the readings of all thermocouples and the flow rate are measured. The parameters of the air entering the unit - temperature t ₁ and relative humidity φ _{1 are} determined by a psychrometer in the laboratory.

The laboratory unit for studying heat and mass transfer during the evaporation of water into the air stream was made at the Department of Heat Engineering, its use significantly increases the accuracy of changing the temperature of the stream, conditions are created to ensure air humidification, an experimental study of the process of heat and mass transfer between water and air flow. The installation is easy to manufacture, intuitive, does not require large expenses and the use of a fan. In addition, it easily reaches the preset mode and allows you to quickly set a new mode of operation.

Claims (1)

Laboratory installation for studying heat and mass transfer during the evaporation of water into an air stream containing a tube-shaped housing, an electric heater, a wattmeter, flow mixers, thermocouples, characterized in that the housing is curved, an electric heater is installed in the vertical lower part, and an elongated pilot is mounted in the inclined upper part of the housing a section in the form of a glass tube wrapped on the outside with a damp cloth, the experimental section is fixed in the housing with needle supports having rubber balls at the ends for slip rotation to remove excess water used fabric tape, airflow mixers are in the form of washers with holes in the center.