Local mechanical forced ventilation.
Air showers, their purpose and areas of application
An air shower is a local air flow directed at a person. With the help of such a flow, i.e. jets of air, it is possible to create local air conditions that are most favorable for human work in a limited area or areas of production. The areas where it is necessary to install air showers are primarily:
- fixed jobs
- places of long-term stay in the premises of workers
- rest places for workers
in Fig. 1 is shown as an example circuit diagram air shower devices at the heating furnace, when outside air is supplied for air showering.
1 – heating furnace with an open or opening opening 2
3 – fixed workplace at opening 2
4 – shower air distributor for supplying a stream of air to the workplace 6
5 – underground channel for supplying fresh outside air to the air distributor.
Air jet condition 6 on fixed workplace 3, which creates an air shower must meet certain hygienic and physiological requirements. Air showers should be performed in the following cases:
- in cases where it is impossible to obtain standardized air parameters in the room by means of general exchange ventilation.
- when achieving certain parameters of internal air in a room due to general exchange ventilation is possible, but requires huge volumes of air.
In many cases, when work is carried out in an environment of noticeable thermal radiation, and the means of general ventilation are insufficient, in order to maintain the required temperature and relative humidity in the workplace and eliminate the violation of thermoregulation between the human body and the environment, air showers must adjust the air conditions . Industrial premises in which an air-dusting device is primarily needed include:
– metallurgical and engineering plants, where air showers are needed for industrial furnaces, rolling mills, presses and hammers and other technological units.
– glass
– bakeries and other enterprises.
Using air showering, you can adjust the following air parameters at fixed workplaces:
1. air temperature,
2. air speed,
3. humidity,
4. concentration of hazards in the workplace.
Due to the movement of air leaving the air diffuser, heat transfer from the human body increases and this circumstance is very important, especially in cases where a person works in an environment of noticeable thermal radiation.
A stream of supply air from the suffocating air distributor must be sent towards the workers and blow first of all on the exposed parts of the body exposed to radiation. If it is necessary to increase heat transfer from the human body, air showers use air with a lower temperature compared to the air temperature in the room. In addition, sometimes, to increase heat transfer from the human body, a stream of released air is sprayed into the lava.
In this case, droplets of water fall on the open parts of the person’s body, on his clothes, evaporate and cause additional cooling of the person.
If an air shower is used indoors to localize emitted dust or to combat increased gas pollution, then the speed of air exit from the shower air distributor should not be significant so that the dust lying on the surface building structure, didn’t get angry.
In practice, this speed should be 1-1.5 m/s. The width of the shower jet S should be approximately 1.2-1.5 m. Except for the case when air showers serve large areas. According to SNiP 41-01-2003 “Heating, ventilation and air conditioning, air showering of permanent workplaces with outside air must be provided in the following cases:
1. when a person is irradiated at a fixed workplace by a radiant heat flux with a surface density of ≥140 W/m2 or more.
2. in open technological processes accompanied by release harmful substances and the impossibility of constructing shelters or local exhaust ventilation, while providing for measures to prevent the spread of harmful emissions to permanent workplaces.
When showering industrial premises with outside air, the calculated temperatures and air speeds must be provided for:
1. when a worker is irradiated with a radiant heat flux with a surface density of 140 W/m2 or more according to Appendix E of SNiP 41-01-2003, depending on the category of work performed and the surface density of the heat flux.
2. When open technological processes associated with the release of harmful substances according to Appendix B of SNiP 41-01-2003.
Table 6. 2 of the designer's reference book, edited by Pavlov and Schiller, shows data from the LIOT Institute on numerical values of the intensity of thermal radiation of workers in the workplace individual species production, for workshops of machine-building plants (forges, foundries, thermal and others) when designing and calculating air showering, the radiation intensity of workers can be taken according to the instructions for the design of heating and ventilation of the corresponding listed workshops. Developed by the SantekhNIIProekt Institute.
Detailed data on the intensity of radiation exposure in working workshops of machine-building plants are given in the reference book by B.M. Torgovnikov. "Design of industrial ventilation."
According to SNiP 41.01-2003, when showering workplaces with outside air, the design parameters of the outside air should be taken as follows according to SNiP 23.01-99*.
1. parameters A for the warm period of the year,
2.parameters B for the cold period of the year.
Air supply by air shower systems for workplaces should be provided through rotating horizontal planes of air distributors ensuring minimal turbulence of the outgoing jet and the possibility of changing and directing the jet of the vertical plane at an angle of at least 30 0 .
Air shower installations for workplaces can be:
1. stationary, see Fig. 1
2. mobile or portable.
Shower installations supplying outside air are stationary and are classified as supply air installations from which they are separated only by devices for supplying fresh air.
Suffocating air in stationary installations is supplied to certain workplaces using air distributors, which, when exiting, produce a concentrated stream exiting at a given relatively high speed (up to 3.5 m/s).
Currently, unified shower air distributors (UDA) are recommended for preferred use in stationary air shower installations. They are designed and can be used in the following versions:
1. with bottom air supply and without humidification, and with humidification.
2. with top air supply without humidification and with humidification
Figure 2 shows the design of a unified shower air distributor with top air supply and UDV UV humidification.
1- air distributor housing
4-joint joint
5- pneumatic nozzle
The air distributor consists of a housing 1 in which guide vanes 2 and devices 6 are located that provide kinematic connection between the block of guide vanes 2 and the guide grille 3.
Changing the direction of the choking jet in the horizontal plane is carried out by rotating the choking air distributor around its axis, for which it has a hinge 4. In the vertical plane, the direction of the jet due to rotation of the guide grille 3 can change from a horizontal position at an angle of up to 45 0 . To humidify the air, nozzles 5 with pneumatic spraying of water are installed on the guide grille. The nozzles can move both horizontally and vertically along the guide grid and thereby create optimal conditions for moisturizing.
A rotary shower air distributor (RPD - rotary shower pipe) can be used as an air distributor in air shower installations, see Fig. 3.
The PPD air distributor consists of 3 units:
– top link
– middle management
–lower link
2 support rollers
4 – hinge
The lower link 5 has a compressed rectangular output section and is connected to the middle link by an axis 4, around which it can be rotated downward at an angle of up to 25 0 .
In a given position, the lower link 5 is fixed by two clamps located on the side surfaces of the middle link; the middle link rotates around a vertical axis on three rollers 2, which rest on the fixed flange of the upper link.
The shower air distributor is attached to the air duct using a flange connection and for this purpose the air duct must be securely attached to the external structures.
PD air distributors (shower pipe) were developed by Professor V.V. Batulin with an upper air supply and a lower air supply. Accordingly, Figures 4 a and 4 b.
1 – air duct from the ventilation system
4-swivel joint
5- handle for changing the positions of the guide grid
The air distributor is rotated around the vertical axis using hinge 4. To cool and humidify the supplied supply air, nozzles FP-1 and FP-2 with pneumatic spraying of water can be used, see Fig. 2. NPO (research and production division) "Projectpromventilation" has developed a rotary adjustable air distributor VP with a connecting pipe of round or rectangular section the design of which is shown in Figure 5.
1 – stationary part of the fan
2 – rotating part of the fan
3 – metal flexible sheet
4 – dividers
5 – fan grille RV, installed in the outlet section of the fan
6 – hinge.
VP fans can be installed vertically with a top air supply, or horizontally with a side supply.
The second type of showering installations are mobile (portable) installations. Air treatment in them usually consists of mixing with the flow of air coming out of the existing structure axial fan sprayed water.
Figure 6 shows a schematic diagram of a mobile shower installation.
1 – axial fan (usually MC series) with electric motor 2;
3 – supporting structure:
4 – pneumatic nozzle.
Of the fan-shaped shower units, called water-air showers, the most common are units of the VA, PAM design, developed respectively by the Sverdlovsk (SNOT) and Moscow (MIOT) Institute of Occupational Safety and Health.
Operating on recirculated room air, these units are characterized by a simple design, provide significant cooling of the supplied choking air, and in addition provide partial washing of dust.
The calculation of the air pressure is based on the patterns of movement of a free stream of supply air and is responsible for determining the following parameters:
1. flow rate of supplied supply air;
2. speed of air exit from the shower air distributor
3. design dimensions and standard size adopted for installation of the air distributor.
An air shower is a stream of air directed at a confined workplace or directly at a worker.
The use of air showers is especially effective when a worker is exposed to heat. In such cases, an air shower is installed at the place where a person spends the longest time, and if short breaks for rest are provided at work, then at the place of rest.
The upper parts of the body should be blown with air, as they are the most sensitive to the effects of thermal radiation.
The speed and temperature of the air in the workplace when using air showers are prescribed depending on the intensity of a person’s thermal irradiation, the duration of his continuous stay under irradiation and the ambient temperature.
Fan unit type VA-1
1 - electric motor;
2 - shell;
3 — mesh;
4 — axial fan;
5 - confuser;
6 — fairing;
7 - pneumatic nozzle;
8 - guide vanes
Air showering should be provided at permanent workplaces with an irradiation intensity of 350 W/m2 or more. In this case, an air flow can be directed at a person at a speed o = 0.5...3.5 m/s and a temperature of 18-24 ° C, depending on the period of the year and the intensity of physical activity.
Constructive implementation of air showers.
The air coming out of the shower pipe must wash the head and body of a person at a uniform speed and have the same temperature.
The axis of the air flow can be directed to the person’s chest horizontally or from above at an angle of 45° while ensuring the specified temperatures and air speeds in the workplace, as well as to the face (breathing zone) horizontally or from above at an angle of 45° while ensuring acceptable concentrations of harmful emissions.
The distance from the shower pipe to the workplace must be at least 1 m with a minimum pipe diameter of 0.3 m. The width of the working area is taken to be 1 m.
Design of VA-1 units
According to their design, showering units are divided into stationary and mobile.
The fan unit type VA-1 consists of a cast iron frame on which is mounted an axial fan No. 5 type MC with an electric motor, a shell with a collector and mesh, a confuser with guide vanes and a fairing, a pneumatic nozzle type FP-1 or FP-2 and pipelines with fittings and flexible hoses for water supply and compressed air. The unit is manufactured with the fan rotated around the axis of the frame up to 60° and the barrel raised vertically by 200-600 mm.
In addition to fan units of type VA, a rotating unit PAM.-24 is used in the form of an axial fan with a diameter of 800 mm with an electric motor on one shaft. The unit's productivity is 24,000 m 3 /h with a jet range of 20 m. The unit is equipped with a pneumatic nozzle for spraying water in the air flow.
Stationary shower installations supply both untreated and treated (heated, cooled and humidified) outside air to the shower pipes. Mobile units supply room air to the workplace. Water may be sprayed into the air flow they supply. In this case, droplets of water falling on clothing and exposed parts of the human body evaporate and cause additional cooling.
Fixed workplaces can be showered with various types of shower pipes. The HIP pipes have a compressed outlet section, a swivel joint for changing the direction of air flow in the vertical plane, and a rotating device for changing the direction of flow in the horizontal plane within 360°.
Regulation of the direction of the air flow in the PD nozzles is carried out in the vertical plane by turning the guide vanes, and in the horizontal plane using a rotary device. PD pipes can be used both with and without nozzles for pneumatic water spraying. The pipes should be installed at a height of 1.8-1.9 m from the floor (to the bottom edge).
Calculation of the air showering system at the metal pourer's workplace
Air showering is one of the most effective measures to combat radiant heat, as well as toxic gases and vapors released during work with forging hammers and presses. Heated (in winter) and cooled (in summer) air supplied from above through special devices supplies the worker with fresh, humidified air, and by adjusting the speed of air movement, a partial decrease in the air temperature at the workplace can be achieved. Sometimes air is supplied to the workplace through flexible rubberized hoses from a mobile air shower unit. Appearance the shower installation is shown in Fig. 3.4.
Figure 3.4 - Showering installation
We will calculate the air shower using the method of B.M. Zlobinsky.
The calculation of air showers comes down to determining the diameter of the shower pipe and the parameters of the air coming out of it.
Diameter cross section jet is calculated using formula 2:
where is the turbulence coefficient, depending on the shape of the outlet section (0.06 - 0.12). Let's take =0.12.
x is the distance from the point of exit of the jet from the nozzle to the workplace. Let's take x = 2 m.
d 0 - diameter of the outlet section of the pipe. Let's take d 0 =0.7.
The speed at which air leaves the nozzle is calculated by the formula:
where area is the average air speed at the work site. This speed should not exceed 0.3 m/s. Let's take area =0.3 m/s;
b is a coefficient varying from 0.05 to 1 depending on the ratio. Let us accept d r.pl. =2 m, then:
Let us substitute the obtained values into (3) and obtain that
The required temperature at the outlet of the nozzle is determined by the formula:
where t o.c. - ambient temperature, it is 20-25 0 C. Let’s take 22.5 0 C.
t cp is the average required air temperature at the smelting site. According to SanPiN 2.2.4.548-96, the permissible temperature on the site is 19-21 0 C, let’s take 20 0 C.
C is a coefficient that, like coefficient b, depends on the ratio and varies from 0.345 to 0.22. Let's take C=0.25.
Thus, in order for the temperature at the melting site to be equal to 20 0 C, an air stream d = 2.05 m is provided at t patr = 19.3 0 C, which is supplied to the melting site by a fan at a speed of 0.15 m/s and productivity 1800 m 3 /h.
Calculation of the economic efficiency of installing an air shower system of type VD-1800 at the metal pourer’s workplace will be carried out in the organizational and economic section of the diploma project.
Diseases caused by exposure to the heating microclimate of foundries (hot shops) and their prevention
Heating microclimate is a combination of parameters in which there is a change in heat exchange between a person and the environment, manifested in the accumulation of heat in the body (> 2 W) and/or in an increase in the proportion of heat loss by evaporation of moisture (> 30%). Exposure to a heating microclimate also causes health problems, decreased performance and productivity.
Working in such conditions can lead to uncomfortable sensations of heat, significant stress on thermoregulation processes, and, with a large heat load, to health problems (overheating).
This kind of microclimate is created in rooms where technology is associated with significant heat releases in environment, that is, when production processes take place at high temperatures (firing, calcination, sintering, melting, cooking, drying). Heat sources are heated to high temperature surfaces of equipment, fences, processed materials, cooling products, hot vapors and gases escaping through equipment leaks. The release of heat is also determined by the operation of machines, machine tools, as a result of which mechanical and electrical energy goes into heat.
Topic 2 Design of air showering of workplaces to improve microclimate parameters and air composition
When a worker is exposed to thermal radiation with an intensity of 0.14 kW/m2 or more (according to GOST 12.1.005-88), air showering is used (supply of supply air in the form of an air stream directed at the workplace). When the irradiation intensity is higher than 2.1 kW/m2, the air shower cannot provide the necessary cooling. In this case, radiation exposure should be reduced by providing thermal insulation, shielding and other measures. Or design devices for periodic cooling of workers (cabins, rest rooms, control stations).
The cooling effect of air showering depends on the temperature difference between the body of the worker and the air flow, as well as on the speed of air flow around the cooled body. To ensure specified temperatures and air velocities in the workplace, the air flow axis is directed towards the person’s chest horizontally or at an angle of 45. The distance from the edge of the shower pipe to the workplace must be at least 1 m. The minimum diameter of the pipe is taken to be 0.3 m. For fixed workplaces, the estimated width of the working platform is taken to be 1 m.
When showering fixed workplaces with treated or untreated air, cylindrical nozzles or rotary shower pipes of the PPD type (series 4.904-22) should be used.
When showering areas where workers are constantly located with treated or untreated air, you should use nozzles with an upper air supply of type PD B (series 4.904-36) or nozzles with a bottom air supply of type PD n (series 4.904-36).
When showering areas with untreated air, rotary aerators PAM-24 and VA (OV-02-134 series) should be used. The PAM-24 aerator consists of an axial fan with a diameter of 800 mm with an electric motor on one shaft. The fan rotates at an angle of up to 60 eleven times per minute. Jet range 20 m.
When showering a group of permanent workplaces, it is recommended to use air distribution devices of the VGK type (series 4.904-68). Air showering is also used during production processes that emit harmful gases or vapors, if the use of local shelters and suction is not possible. In this case, to ensure acceptable concentrations of harmful substances, the air stream is directed into the breathing zone horizontally or from above at an angle of 45.
Technical data of shower pipes and distribution devices are given in .
Thus, air showering is used in the following cases:
1) With increased intensity of thermal radiation and especially in cases where it is not possible to use other methods of protection (for example, heat shields).
2) When elevated temperature air in the work area.
3) With an increased concentration of harmful substances in the work area.
Design order air showering in case of thermal excess in production premises.
1. Determine standard air temperature values t air flow standards and speeds v standards for air showering according to and depending on the following factors:
– intensity of thermal radiation in workplaces.
2. We set the air temperature at the outlet of the cooling device t cooling and heating of air in air ducts t when air moves from the cooling device to the shower pipe.
3. Determine the air temperature t o at the outlet of the shower pipe
t o = t cool + t, С (2.1)
4. Determine the ratio of temperature differences
Where t o – air temperature at the outlet from the shower pipe, ˚С;
t r.z. – air temperature in the working area outside the air flow, ˚С;
t normal – standard air temperature in the workplace, ˚С;
5. We select a shower pipe for installation according to and and determine its characteristics:
– type of pipe;
– angle of inclination of the guide vanes of the pipe to the horizon , ˚;
– temperature coefficient n;
– air flow velocity attenuation coefficient m;
– coefficient of local resistance of the shower pipe K m.s.
6. According to the conditions of the workshop (room), we accept the installation height of the shower pipe above the level of the working platform h.
The installation diagram of the shower pipe above the working platform is shown in Figure 2.1.
Figure 2.1 – Installation diagram of the shower pipe above work surface
Legend in the figure:
h– installation height of the pipe above the working platform, m;
h h – the height of a person from the floor to his chest, m;
– the angle of inclination of the guide vanes of the pipe to the horizon;
x– distance from the shower pipe to the workplace, m;
7. Determine the distance from the shower pipe to the workplace
, (2.3)
We determine the estimated area of the outlet section of the shower pipe.
At P T< 0,6
(2.4)
9. Select the nearest standard pipe according to or and determine its cross-sectional area F y from the condition
F y F O.
10. Check the length of the initial section of the jet by air speed
(2.5)
Length of the initial section of the jet 
shows that within this area the speed of air movement is constant and equal to the flow speed at the exit from the shower pipe.
11. Determine the speed of air movement from the shower pipe:
(2.6)
12. Calculate the estimated amount of air per shower pipe
(2.7)
13. Check the length of the initial section of the jet 
by temperature
(2.8)
14. Determine the air temperature at the outlet of the shower pipe
(2.9)
At 
We believe that the selected pipe and the operating mode of the air conditioner will provide the necessary air flow parameters.
At 
<
it is necessary to change the adopted design decisions and repeat the calculation of the pipe area.
15. Determine the amount of air per one shower pipe, taking into account the reserve coefficient of air flow K h.
, m 3 /s (2.10)
16. Determine the cross-sectional area of the supply air ducts to the shower pipe.
We take the diameter of the supply air ducts equal to the inlet diameter of the shower pipe according to or.
17. We accept, according to the workshop conditions, a diagram for supplying air to the shower pipe (see the previous topic of practical training).
18. Determine pressure losses in air ducts.
19. Select a fan or air conditioner to ensure the required air flow parameters.
At P t = 0.6-1.0 calculations are carried out using the formulas:
(2.11)
(2.12)
At P t > 1.0 calculations are carried out using the formulas
(2.13)
(2.14)
It should be taken into account that when P T< 1,0 применяют адиабатичесое охлаждение воздуха. При P t 1.0 artificial air cooling is required.
Design order air showering when harmful substances are released into production premises. Calculation is carried out according to the formulas
Where WITH r.z. And WITH o – concentration of harmful gas and dust vapors in the air working area and air supplied from the shower pipe, mg/m 3 ;
MPC – maximum permissible concentration of harmful substances in the air at the workplace, mg/m 3 (according to GOST 12.1.005-88).
At P To< 0,4 расчет ведут по формулам
At P k = 0.4-1.0 calculation is carried out according to the formulas
;
;
.
When radiant heat and emissions of dust and gases enter the premises at the same time, calculations are made for each hazard separately. Further calculations are made using a large pipe made from those calculated for each type of harmful substance.
References
1. Means of protection in mechanical engineering: Calculation and design: Directory / S.V. Belov et al. – M.: Mashinostroenie, 1989. – 368 p.
2. Internal sanitary installations. In 2 parts / Ed. I.G. Staroverova // Part 2. Ventilation and air conditioning: Designer’s Handbook. – M.: Stroyizdat, 1978. – 509 p.
3. SNiP 2.04.05-86. Heating, ventilation and air conditioning / Gosstroy USSR. – M.: CITP Gosstroy USSR, 1987. – 64 p.
4. Handbook of labor protection at industrial enterprises / K.N. Tkachuk et al. – K.: Tekhnika, 1991. – 286 p.
Task No. 1 for the practical lesson "Design of air showering"
Air showering is organized in the production area. It is necessary to determine the required air exchange for one shower pipe (m 3 /h). The initial data is given in Table 2.1.
Task No. 2 for the practical lesson "Design of air showering"
Air-suffocation of workplaces is organized in the production area. Determine the pressure that the fan must develop to ensure the required air flow parameters. The initial data is given in table 2.2.
Table 2.1 – Initial data for task No. 1 (t r.z. =32˚C)
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Options |
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Pipe type |
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Tilt angle, α |
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Coefficient,n n |
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Coefficient,m n |
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Coef. losses K P m.s. |
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Sectional area of the pipe, m 2 |
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Permissible air speed at the workplace, m/s |
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Permissible air temperature, ˚С |
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Distance from the nozzle to the workplace, m |
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Installation height of the pipe above the working surface, m |
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Table 2.2 – Initial data for task No. 2
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Options |
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Pipe type |
PD V -3 |
PD V -5 |
PD n -4 |
PD n -3 |
PD V -4 |
PPD-5 |
PD V -3 |
PD V -5 |
PD n -5 |
PPD-8 |
PPD-6 |
PPD-10 |
PPD-8 |
PD V -4 |
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Coef. losses K P m.s. |
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l 1 , m |
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l 2 , m |
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l 3 , m |
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l 4 , m |
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l 5 , m |
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l 6 , m |
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Ud. friction losses, Pa/m |
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Air density, kg/m3 |
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Allocation per pipe, m 3 /s |
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Filter losses, Pa |
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D under, m |
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Class 36d, 1a, USSR esievznm
Iatenaa-teeeeeekav
P. V. Uchastkin
VENTILATION SHOWER UNIT FOR WORK
INSIDE HOT PRODUCTION EQUIPMENT
In some cases, it becomes necessary! It is necessary to carry out work inside a hot production equipment. These include renovation work in the furnaces of powerful electric steam boilers
: stations, hot open hearth furnaces, as well as work on production operations inside furnaces for heating and firing various products, etc.
These works are carried out under conditions of high temperature (up to 100), which is caused by the need to reduce downtime of the specified production equipment. These works are very difficult and cannot be carried out for a long time.
L7H To facilitate such work, a mobile ventilation showering unit is offered. The principle of operation of the installation is aimed at creating a zone in the hot space low temperature by supplying air at a lower temperature than the temperature inside the hot equipment.
A distinctive feature of the proposed installation is the method of protecting the air shower torch from excessive new-! singing temperature when mixing the surrounding grief:.ci o Air.
Known designs of such installations do not provide protection for the suffocating 1ra kel and Ot na Grs VYA1. To avoid this disadvantage, it is proposed to install water spray nozzles on the shower nozzle. which create a curtain of finely atomized water on the periphery of the air plume. Hot air sucked from the surrounding space towards the main stream meets sprayed water on its way. Intense IIcoapeHIIe of water occurs, as a result of which the ambient air temperature decreases, which leads to a significant decrease! !o temperature in the choking torch.
To move the torch, it is proposed to use a flexible air duct, at the end of which 11PIHI Pe11.7PH d31INRU1oshi1 pump current. H!OH:Ioå can be mounted on a stand so that it can be rotated as needed! direction. No. 84128
Drawing 1 (Fig. 1) shows a diagram of a ventilation shower installation in operation; Fig. 2 – installation without hose, side view; in fig. 3 – “the same, front view.
Ventilation unit @4th unit of the installation consists of a medium-pressure centrifugal fan 1 and an electric motor 2. Mounted on the motor shaft impeller fan The fan and electric motor are mounted on a trolley 3, which has three wheels: two of them are mounted on a common axis, the third is rotary. Turning the wheel Exec. 1 II cT c H Il P H Il o M o IH H P g H o B T II H . T I koso f O R vI;1 0 H H e x o I O B o l l I B c T H t e l e kkn provides it with good maneuverability. The fan inlet is covered with a mesh. To wind the rubber pad 11GYA 4, use reel b.
A starting device 6 of the electric motor, consisting of two package switches, is mounted on the trolley frame. One of the switches is used to turn the engine on or off, the other is used to switch phases, so that for any connection to the network electric current the direction of rotation of the electric motor required for the fan was ensured.
The air duct 7 is made of a flexible metal hose and has a length of 6 l. For more convenient use, it consists of two links, connected “at the end” using cuffs and locks. At one end of the duct there is a square flange for connection to the fan outlet, and at the other end there is an adapter pipe with a round flange and tightening locks for connection with the shower nozzle 8. The last one is an adapter outlet, inside of which 10 guide vanes are installed. The nozzle is articulated with a tripod 9, there is a round flange around which it can freely rotate 360. On the top of the nozzle, a tap 10, a tube for water supply and 11 water sprayers with an outlet diameter of 0.6 l1m are fixed.
To prevent clogging of the water sprayers, a mesh filter l2 is placed on the rubber hose. The hose has an internal diameter of 10 mm, at one end there is a union nut for connection to the tube of the sprayers, and at the other end there is a nut for connection to the tap on the water supply.
The worker must be in the area of the air flow emerging from the nozzle, so that the head and upper body are in the flow.
When a worker moves, the shower flow is directed to a new location by rotating the nozzle around its axis.
The installation allows you to reduce the temperature in the workplace by
30 - 50C. If usually after 5 - 10 l1in of stay inside the furnace of a boiler or open-hearth furnace, the worker’s body temperature reached 39, then when working with the proposed installation and for 30 11 to one hour, the body temperature was 37. ,1", the essence of the invention
1. Ventilation showering installation for work inside hot production equipment, characterized by the fact that, in order to prevent an increase in the temperature of the showering air torch from mixing ambient air into it, water spray nozzles are installed on the periphery of the showering nozzle, creating water curtain around the air torch, ensuring a decrease in the temperature of the intake air. No. 84128
2. Installation according to item 1, specifically with the use of a flexible air duct, at the end of which a shower nozzle is attached, in order to bring the shower torch closer to the place of work.
3. Installation according to paragraphs. 1 and 2, characterized in that the shower nozzle is mounted on a stand with the ability to rotate it to direct the shower torch. No. 84128
11odp. to the stove 30j. (II - 61
Oum format. 70 108)i;
CBTI at the 1st (omitsts for affairs of innovations and discoveries of the prp Council of Ministers of the USSR
Moscow, Center, M. Cherkassky per., 216.
Volume It, 35 ed. l.
Price 7 kopecks.
Printing house, Sapunova Ave., 2, Editor N. I. Mosin Tskred A. A. 1 (Udryavitskaya 1 (orr. R. Rabinovich