SU1318347A1 - Method and apparatus for air exchange of tunnel chamber for cooling moulds and castings - Google Patents

Abstract

SUBSTANCE: invention relates to foundry production and may be used in accordance with the invention / s / s 6 Z7, 252 i-dS IL P 12 VJ tJ-T; iJt h //. II in I 11 I U1 / fX / ia NPO as: Wl is used in areas for cooling molds and castings in foundry lines. The purpose of the invention is to improve working conditions and save energy. This is achieved by isolating the volume of the cooling tunnel chamber, using outside air and reducing the volume of flowing air drawn from the workshop. The method is carried out by the device of a tunnel chamber 1, in which the air removed from it is compensated by supplying the outer untreated and partially treated (mixed with recirculated) air through the nozzles 11 of the central part of the chamber and additional devices 15 and 17, made as slotted nozzles located in the zone of the front entrance 2 and output openings 3 along the walls of the tunnel chamber and oriented in the opposite direction. the direction of the natural flow of air. 2 sec. and 2 z. p. f-ly, 2 ill. Into the atmosphere of Iza / Pmosfe / s 6 Z7, 252.25 / V 12 VJ -T H //. I 11 I У1 / f-I М z 7 (L 00 00 CO 4 vl 11 I У1 / fX tUEUd / Doa 3 ncn ich

Description

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The invention relates to foundry and can be used in the production of castings from iron and steel in the cooling areas of molds and castings of conveyor casting lines.

The method of cooling the casting molds and castings is as follows. The molds and castings are cooled in the chamber, the air regime is practically isolated from the workshop by additionally supplying incoming compensation external air in the zone, end inlet and outlet openings preventing unorganized air flow through the openings and running along the walls of the tunnel chamber.

natural flow of air through the openings, and forced removal of heated gas air into the space between the main and additional supply air supply points.

The minimum velocity in the cross section of the open part of the end opening is determined from the condition of maintaining the maximum permissible concentration of harmful substances in the working area at the opening according to the formula

opening, m / s;

air exchange rate in the room, 1 / s; the cross-sectional area of the open part of the aperture, the distance of the open part of the aperture, m;

maximum air velocity in the working area, M / S,

concentration of harmful substances near the opening

.G,

 0.9 - them

Where

Gp cha

the amount of harmful substances in the chamber, mg / s; HC, air exchange in the chamber, m / s, concentration of harmful substances in the workshop at a distance of about the chamber, mg / M;

q - concentration of impelled substances in the working area, equal to the MPC, mg / m.

The values of K. and a are techno

They are appointed by technologists depending on the type of conveyor and the conditions of its serviceability.

To ensure the temperature of the supply air supplied to the tunnel chamber during the cold period of the year, the primary and secondary supply compensated outside air is mixed in certain proportions with the forcedly removed raw gas.

FIG. 1 is a schematic diagram of the air exchange device.

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five

tunnel chambers for cooling cast forms and castings in the cooling section of the forming conveyor LINE; in fig. 2 is a variation of the seasonal adjustment scheme for the system,

5 working only on the outside air; in fig. 3 shows section A-A in FIG. 1 (pa; tubes for venting air from the chamber); in fig. 4 shows a section BB in FIG. 1 (nozzles giving air in the central part of the chamber); in fig. 5 shows a section B-B in FIG. 1 (optional main fixture); in fig. 6 - section G-Y in FIG. 1 (additional backup device).

The device contains a tunnel chamber 1 with open end inlet 2 and outlet 3 openings for transporting molds 4 and castings, equipped with supply air supply air, including: pipe 5 supplying external air to ventnal packaging 6, duct 7 through which air flow

 It goes into the mixing chamber 8 of the load and recirculated air, the distribution duct 9, which supplies air from the mixing chamber to the air distribution points, through the duct 10 to the main supply air nozzle 11 (there may be several), through the duct 12 through the distribution chamber 13 to the additional equipment m by the duct 14 to the main slotted nozzle 15, oriented in the direction of the opening, and the duct 1 6 to the backup slot nozzle 17 ,. oriented inside the camera, including the signal from the sensor

0

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18 temperatures, by means of a heated gassed air removal system, including nozzles 21 for removing air from the chamber, placed along the length of the chamber between the main points of supply of supplying compensation air and in the space between the main additional supply points, air ducts 22 through which exhaust air enters into the collecting chamber 23, the filter 24 (if necessary, cleaning the air), the distribution chamber 25, from which part of the air is taken for recirculation through the air ducts 26, the air duct 27, the fan 28 and duct 29 through which exhaust air is vented to the atmosphere.

In the case of system operation only in the outside air (Fig. 2), the equipment elements 8 and 25 connected with recirculation and the corresponding air ducts 26 are disconnected from the scheme, and the supply nozzles of the main supply 30 and air inlets 31 that only work in the summer period are added. .

The device works as follows.

Exhaust air in a volume of bm, corresponding to the calculation of the technological process, is sucked out of chamber 1 through nozzles 21 by the heated gassed air removal system with air purification in filter 24 and partial recirculation, the amount of air coming from the LU shop is maintained by the device ancillaries 15 and 17 for supplying supplying compensation air at a minimum level that ensures the maximum allowable concentration in the service area, supply air compensation in total volume bn, equal to the difference, and 2 Ly, are supplied by the supply system partially in volume L to additional devices with slotted nozzles the main 15 and reserve 17, preventing unorganized flow through the opening, and in volume LL - Ltt to nozzles 11 in the central camera zone.

The accessory at the end opening with the direction of flow outward 15 is the main one.

and with the direction of flow inward - back-up 17. Air is supplied to the backup slit nozzle 17 by an automatic control system from a common fan 6 by a signal from temperature sensors installed in the upper part of opening section 18, in the upper zone of the chamber near opening 19 and in the workshop 20 when the temperature in the opening space and in the chamber is equal and the temperature in the workshop exceeds this temperature by more than 3, and the supply volume is adjusted until the temperatures are equal.

The use of air recirculation is advisable when cooling steel castings in a cooling tunnel. In this case, the temperature of the supply compensation air is maintained in the cold period of the year by an automatic control system (not shown) at a constant level, for example, by changing the mixing ratio of the recirculated air and the outside air. During the warm period of the year, recirculation is turned off and cooling is carried out only with outside air. The air exchange in the chamber and the capacity of the fans are automatically controlled in a sliding mode due to the fact that the temperature of the exhaust air is kept constant, for example 45 ° C.

When cooling the casting molds and using only external air, the system of supply and exhaust ventilation of the chamber is performed in two positions (Fig. 2) with the summer system switched on at the outdoor air temperature above 10 ° C.

The year-round calculation system is calculated on the average temperature of the heating period, for example, O C, air exchange in the summer period is determined by the temperature of the highest cost, for example, 20 s. Fans for the summer system are selected based on the calculated difference in air exchange during the warm and cold season.

For all the options and modes of operation of the cooling system for casting molds and castings, the volume of air coming from the workshop may be based on a calculation of 0-40% of the outgoing volume, since the compensatory volume is from 100 to 60% of the outgoing and cooling forms and castings. in the chamber at

51

the proposed method is actually made autonomously from the workshop. When using outside air in winter, the cooling process is intensified and the residence time of the molds in the cooling tunnel can be reduced, i.e. increased conveyor speed and line capacity (is a production reserve).

Claims (4)

1. Air exchange method for tunnel chambers for cooling casting molds and castings, including removal of heated polluted air from the chamber and supplying compensation air to the chamber, characterized in that, in order to improve working conditions by preventing unorganized air flow through the end openings and save energy for the preparation of the intake air of the workshop, compensation air is additionally supplied in the zone of the inlet and outlet openings inside the tunnel chamber, and the removal of the heated air; the ear is produced between supply air supply points. 2. The method according to claim 1, of which is compensated for the fact that the compensating outside air is mixed with the untreated gas air forcibly removed from the tunnel chamber. 7 6 3. An air exchange device for tunnel chambers for cooling casting molds and castings, comprising a tunnel chamber with inlet and outlet face openings, a casting conveyor for transporting molds and castings, devices for removing heated gassed air and supplying compensated air, air ducts, characterized in that to improve working conditions by preventing unorganized flow of air through end openings and eco nomii energy to prepare, inflow air shop, it is equipped with a mixing chamber, accessories for supplying supplying compensation air installed in the area of the inlet and outlet openings made with slotted nozzles located at the walls of the tunnel chamber and oriented towards the opening, while the device for removing heated gaseous air are placed between the main and additional supplies for supplying compensating air, and devices for supplying and venting air are interconnected by ducts through the mixing chamber. 4. The device according to claim 3, characterized in that it is provided with back-up slotted nozzles installed in the upper part of the chamber in cross-section of the end inlet and outlet openings oriented inside the tunnel chamber and connected by air ducts through the distribution chamber with appropriate accessories of air. Editor S.Patrusheva Order 2457/9. Circulation 740 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 Compiled by E.Ivanko Tehred M.Hrdanich Proofreader S.Shekmar