66 results about "Explosive atmospheres" patented technology

A portable radio and battery pack configuration favoring higher available transmit power in explosive atmosphere applications includes a radio device (302) and a battery pack (304) removably attached to the radio device. The battery pack includes at least one of an audio power amplifier (346) and a radio frequency (RF) power amplifier (356), and a battery (306) for supplying power to the radio device and to the at least one of an audio power amplifier and a RF power amplifier.

Disclosed is an apparatus and method for operating powered air-purifying respirators safely in explosive atmospheres. The apparatus and method utilize a current control means for sensing a current flow from a battery to a motor, and stopping the current flow when the current flow exceeds a threshold value for a predetermined amount of time. Upon sensing that the current flow has exceeded the threshold value for the predetermined amount of time, the current control means immediately stops the current flow. The apparatus and method provides sufficient power to properly start and operate the motor by providing a soft start to the motor by limiting the duration of higher than threshold operating current to intervals shorter than the predetermined amount of time. Pulse width modulation is used to ramp-up the motor to speed by supplying pulses of energy to the motor that will not cause the current control means to stop the current flow.

The invention concerns a method for anticipating and/or delaying and/or preventing the risk of spontaneous combustion and/or explosion of an explosive atmosphere preserved in a confined or semi-confined medium, which consists in measuring the temperature of the mixing from the moment said mixture has been created and determining the critical moment of spontaneous combustion and/or explosion of said atmosphere by determining the unexpired inducting period, on the basis of the time which has elapsed between the creation of said atmosphere and the critical moment beyond which there is a risk of spontaneous combustion and/or explosion of said atmosphere.

The invention provides a preparation method of zinc oxide nano-particles for fast detecting explosive atmosphere. The method includes two steps that zinc oxide nano-sheets are prepared and the zinc oxide nano-particles are formed in the annealing treatment process. Zinc oxide prepared through a sol-gel method and transition metal doped zinc oxide are of a nano-sheet structure and a nano-particle structure, transition metal doping can change the energy band structure of the nano-sheet structure and the nano-particle structure of the zinc oxide and increase the surface defects of materials, and therefore the gas-sensitive property of the materials is improved. A zinc oxide nano-particle material obtained through the method can sensitively and fast detect the detonable atmosphere with the raw materials being ammonium nitrate, urea and various nitro-explosives such as trinitrotoluene, dinitrotoluene, nitrotoluene, picric acid and cyclonite at room temperature of 25 DEG C in 2-50 seconds, responding is fast, and the detection limit is low.

The invention discloses a pressure sensing device adapted to corrosive or explosive atmospheres, particularly intended to equip a flowmeter of fluidic oscillator type, comprising a pressure orifice (3) linked to a measuring circuit (4) so as to send audible signals to a measuring membrane (1) fixed into a measuring cavity (2), a deformation sensor (5) sensitive to the deformations of this membrane and capable of converting them into electric signals, and an electronic amplifier associated with this deformation sensor (5). The invention is characterized in that the measuring circuit (4) comprises corrosion and explosion-proof protection means (7, 8, 9) and filtering means (9, 10; 11, 12; 13, 2) for filtering the audible signals so as to enable the disturbance frequencies of these signals to be removed.

The invention relates to an anti-explosion safety design method of a skin-effect anti-explosion power supply junction box, which comprises a cable lead-in device, an element lead-out device, an input three-core cable, a shell, a connection terminal, anti-explosion insulation plaster, a skin-effect heating element and a high-temperature electric wire. The method comprises the following steps of: 1. preferentially taking actual skin-effect thickness to realize the personnel safety and economical efficiency; 2. enabling the maximum surface temperature of the shell to reach a specified anti-explosion value by raising the temperature in a connecting line cavity; 3, guaranteeing the anti-explosion performance of the connecting line cavity by using an isolation structure to cut off the gap of the connecting line cavity; 4. guiding static to a ground protection insulation layer by using an arc extinction electric wire; 5. meeting the anti-explosion requirements on electric clearance, creep age distance, insulation material comparative tracking index classification, and protection grade; 6. achieving electrical safety protection function and meeting the anti-explosion electrical safety requirement by arranging a grounding protection device on the surface. The invention solves the problems of the design of structure, installment and safety technology of anti-explosion power supply junction boxes in dangerous places and areas in an explosive atmosphere.

The invention relates to a transient electromagnetic underground detecting instrument which comprises a main engine, a transmitter, a power supply, a transmitting coil and a receiving coil. The main engine sends operational orders to the transmitter through a main engine connecting line. A power supply adjusting plate, a current plate and a transmitting plate are arranged in the transmitter. The power supply is a large current power supply, and total voltage provided by the large current power supply is 24 volt(V)-36V. Length of the transmitting coil is 6m-10m, and transmitted power is improved. The power supply adjusting plate, the current plate and the transmitting plate arranged in the transmitter are integrated to form an integrated transmitting plate, and a size of the transmitter is reduced. The transmitter is provided with an explosive-proof cavity and a connecting line cavity, the power supply and the integrated transmitting plate are arranged in the explosive-proof cavity, and explosive atmospheres in an outside world and a launcher with large current are isolated to guarantee using safety. The explosive-proof cavity is composed of an explosive-proof shell body, materials of the explosive-proof shell body are acrylonitrile butadiene styrene (ABS) engineering plastics which accord with coin mine safety requirements, weight of the transmitter is reduced, and exploration efficiency is improved largely.

The invention relates to a gravity action-type ball valve instantaneous opening and closing control device. The device comprises a valve assembly, a drive limiting assembly, a power assembly, a jack (11) and an electromagnetic locking mechanism (9). The valve assembly comprises a valve body (1) and a valve element (2). According to the drive limiting assembly, a drive wheel disc (3) is connected with the valve element (2) and drives the valve element (2) to rotate, and a movable limiting block (4) and a reset handle (5) are arranged on the drive wheel disc (3). The power assembly comprises a steel cable (7), a reversing pulley (8) and a balance weight (10). One end of the steel cable (7) is connected with the drive wheel disc (3), and the other end of the steel cable (7) winds across the reversing pulley (8) and then is connected with the balance weight (10). Compared with the prior art, the gravity action-type ball valve instantaneous opening and closing control device is large in ball valve drift diameter, small in medium passing resistance and good in sealing property. The forward and reverse movement inertia influence can be avoided, opening and closing can be achieved quickly, and the valve opening and closing time can be controlled by changing the balance weight. The gravity action-type ball valve instantaneous opening and closing control device can be used in an explosive atmosphere and has the advantages that the manufacturing cost is low, the structure is simple and maintenance in the using process is easy.

The invention discloses a blast-proof and anti-falling protector used in the hazardous environment. The protector comprises a conical casing of which the inner cavity is invertedly conical, and a conical iron core of which the external wall is arranged in the conical casing in an inverted conical shaped; nuts surrounding the conical iron core and belleville springs which are butted between the nuts and the inner cavity of the conical casing are arranged at the top end of the conical casing; a diode safety barrier is arranged on the conical casing; the nonessential safety end of the diode safety barrier is connected with a motive power source, and the essential safety end of the diode safety barrier is connected with a safety switch; a centrifugal block base and a centrifugal block which is arranged in the centrifugal block base and is fixed by a spring pressing sheet are arranged at the bottom of the conical iron core. According to the diode safety barrier, the safety switch s connected with the motive power source in series by the diode safety barrier, so that a non-energy-limited circuit does not affect an energy-limited circuit, the effect of isolating the non-energy-limited circuit from explosive substances can be realized, the blast-proof performance of the protector can be effectively guaranteed, and the risk of working in the potentially explosive atmospheres can be reduced. The blast-proof and anti-falling protector is used for the field of blast-proof protectors.

The invention discloses a diesel engine tail gas two-stage water-air separation and cooling washing box for explosive atmosphere, and belongs to the field of power machines. The diesel engine tail gastwo-stage water-air separation and cooling washing box comprises a washing box body with a tail gas inlet, and the washing box body is divided into an upper part and a lower part communicating through a communicating opening. Cooling water is arranged on the lower part of the washing box body, and an exhaust pipe leading into the cooling water is arranged in the tail gas inlet. A gas outlet is formed in the top end of the upper part of the washing box body, and a two-stage water-air separator is further arranged in the washing box body. An air inlet and an air outlet in the upper end of the water-air separator are formed in the upper part of the washing box body, and the air inlet of the water-air separator is opposite to the communicating opening. A water outlet in the lower end of the water-air separator is formed in the cooling water of the lower part of the washing box body. According to the diesel engine tail gas two-stage water-air separation and cooling washing box, the coolingwater gasified through high temperature is converted into the liquid state again to the maximum extent and recycled into the washing box body again, and consumption of the cooling water is reduced.

The invention relates to a unit for pumping flammable products capable of forming an explosive atmosphere from a pumping zone to a storage chamber, comprising: a separator for separating said products into a liquid/pasty phase and a gas phase, a positive displacement pump for returning non-gaseous products to said storage chamber, means for placing the separator under vacuum, and a circuit for discharging the gases produced by said unit to at least one demarcated discharge zone. The invention also relates to a corresponding pumping process.