SU957921A1 - Method of preventing self-inflammation of porous elastic materials - Google Patents

Description

. The invention relates to fire prevention and can be used to prevent spontaneous combustion of porous elastic materials during their preparation, storage and transportation. A method is known for preventing spontaneous combustion of porous elastic materials by vibro-loading and creating periodically a controlled pressure gradient in the bulk of the material with the frequency of its own pressure gradients l.

The disadvantage of this method is that it does not provide a sufficient cooling rate for the material, which, under the conveyor conditions of its production, leads to an increase in the fire hazard of production.

The object of the invention is to increase the intensity of the process of preventing spontaneous combustion of porous elastic materials.

The goal is achieved by the fact that in the method of preventing spontaneous combustion of porous elastic materials by vibro-loading and creating a periodically varying pressure gradient in the bulk of the material with a frequency of natural oscillations, vibro-loading is carried out by introducing into the material a current with temperature and flow rate 1 -ten. m / s

The method is based on the excitation of cortical, oscillatory movements of the elastic walls of the pores and cells of the material during the beating of them by the introduced gas flow. Under the influence of the emerging gradient

10, the pressure of the cold gas is moved in the bulk of the material, mixed with. 14s is found there with more heated gas and cools it and the material. A mixture of cooling and cooled gases through the side and end surfaces of the block material then enters the environment.

When introducing gas in a discontinuous mode, the process is cooled20 or not intensified. The maximum cooling rate is achieved when the frequency of the gas supply pulses coincides with the natural frequency of the mechanical oscillations of the cooled

.25 material.

Example. Three freshly made blocks of polyurethane foam brand M-75, dimensions 2 1x 0.8 m are placed on a solid base. Cooling the first control unit

They are implemented by vibrating IV-92 vibrator, which is freely placed on the upper surface of the unit.

The second unit is cooled by introducing into the material a stream of air with temperature C and a flow rate of 1.5-2 m / s s. the sides of the bottom surface through a nozzle with a diameter of 10 mm with an excess air pressure of 0.06-1.1 MPa.

The third unit is cooled similarly to the previous one, but the air is supplied in the form of pulses obtained by periodically closing the duct with a frequency of 1-2 Hz.

Thermocouples are introduced into the central zones of all three units. The dynamics of temperature change is recorded with a 1СС-4 potentiometer. Upon reaching-temperature / Jft-ififu fi, the exposure is stopped. The average cooling rate is given by the unit per square meter Kaij and the fraction of the fraction R of the temperature drop that is expected to be influenced. /,

Results, measurements are compared.

The described method provides an increase in the cooling rate of 2-3

times compared with the known. Accordingly, the process of preventing spontaneous combustion of material is intensified. The method is effective when used as a cooling agent of inert gases and air with a temperature within lO-lOO C and a flow rate of 1-10 m / s.

Claims (1)

1. USSR Author's Certificate in Application No. 2716562 / 29-12, cl. A 62 C 11/00, 1979.