156results about How to "Good pressure relief effect" patented technology

The invention relates to a method for releasing pressure and removing danger of rock burst. The effects of releasing pressure and removing danger of rock burst and ensuring the safety of a coal mine can be effectively realized. The method comprises the following steps of: releasing pressure and bursting a coal bed; because of higher inner stress in the coal bed, drilling a roadway wall to form a free space, so that the stress is re-distributed; drilling to enable pressure and water solution to enter a coal body and increase water content; bursting a top plate of the coal bed; bursting a bottom plate of the coal bed; through high pressure, filling fracturing fluid into cracks and slots which are formed in the coal body before fracturing and after fracturing; expanding, extending and dredging the cracks; increasing the slots of the coal bed; changing the magnitude and the direction of the stress on the coal body; transmitting the stress to the deep part of a coal-rock mass; and selecting the safe coal bed or coal body to exploit, wherein after a goaf area and a natural caving arch are formed, an unloading effect is achieved, the rock burst and roof collapse are prevented or relieved. The method is stable and reliable, good in pressure-releasing and danger-removing effects, and high in economic and social benefits, prevention and control on the rock burst are realized, and the safe production of the coal mine is effectively protected.

The invention discloses a numerical simulation determination method of a deep high-stress roadway drilling pressure relief parameter. Before simulation is carried out, a test roadway surrounding rock sample is firstly subjected to a loading and unloading test in a laboratory, an attenuation relationship between a rock sample strength parameter and a damage variable is obtained by fitting and is embedded into a FLAC<3D> (Fast Lagrangian Analysis of Continua) built-in strain softening constitutive model, and an actual measurement mine pressure expression law of a test roadway is taken as a known characteristic value to carry out inversion on the numerical calculation model parameter of a rock mass. A deep roadway drilling pressure relief numerical calculation model is established to simulate and analyze the influence law of a pressure relief drilling orientation, pressure relief opportunity and drilling parameters (diameter, length and inter-row spacing) on the stability of roadway surrounding rock, and a determination method of each factor which affects a pressure relief effect is put forward, and a drilling pressure relief technology system is perfected. The numerical simulation determination method considers the mutual action relationship of a pressure relief degree and the stability of the surrounding rock while pressure relief drilling parameters are determined, and the designed pressure relief drilling can perform a maximum pressure relief effect on a premise that the stability of the surrounding rock is guaranteed. The method is simple and exhibits high application value.

The invention relates to an application of a non-coal pillar roadway layout in the under-protected stratum exploitation. The non-coal pillar roadway layout comprises a stagger arrangement or gob-side entry driving roadway layout, the non-coal pillar roadway layout is adopted in the under-protected stratum exploitation of a dynamic disaster coal stratum, and a coal pillar supporting overlying strata between adjacent work surfaces is removed, so the inclined continuous recovery of a stope is realized; and a fracture zone above the stope ascends and the arrangement of the protected coal stratum in the fracture zone descends with the increase of the exploitation range, so the application range of the under-protected stratum exploitation is widened, the mining is full, the destressing effect is obvious, and the protected stratum is not influenced by the installation of the coal pillar in the protected stratum, thereby the safe and economic exploitation of the protected stratum is realized.

The invention provides a deep hole explosion top board attenuation method. The method solves a problem that it is difficult to control present rock burst under conditions of hard top board, hard base plate and hard coal seam. The deep hole explosion top board attenuation method comprises the following steps: firstly, punching a blast hole in a top board above coal pillar; then packing blasting powder into the blast hole; and lastly, carrying out explosion. According to the invention, an ingeniously-designed blast hole arrangement form, and reasonable explosion parameters are utilized, directly exploding and pressure relieving in stress peak value region are carried out to reach an aim of preventing rock burst, thereby occurrence frequency and energy value of the rock burst on working surface are greatly lowered. With the method, the working surface status is improved and the occurrence of the rock burst in roadway is avoided. The method creates favorable conditions for normal production of the mine, and the method possesses an especially substantial economy and social benefit.

The grouped coal bed exploiting method features that grouped coal bed exploiting process from top to bottom includes the first exploitation of the upper non-protuberant coal bed as protecting layer; the subsequent exploitation of lower protected coal bed; and final exploitation of the protected coal bed with ever serious protuberant danger, so as to form multiple protection of the protuberant coal bed while releasing gas pressure of the protected coal bed for forced pumping. The said method can prevent effectively coal and gas burst disaster radically to double the extracting progress, lower gas pumping cost and realize the safe and efficient intensive extraction of high gas content and low penetration coal bed.

The invention discloses a ventilation pressure leakage sound barrier module, belonging to the noise reduction field. The module comprises a ring-shaped rigidity frame, a plurality of regulation screws and noise elimination vanes which correspond to the regulation screws and can freely rotate around the regulation screws; the noise elimination vanes are arranged in the ring-shaped frame regularly to form a shutter structure which can freely rotate. The module of the invention adopts the rotatable design of the noise elimination vanes, can reach more excellent ventilation noise elimination effect by regulating the wind facing angle of the module, realize free selection of different noise elimination ranges and ventilation amount, and simultaneously also changes the direction of noise radiation; in addition, the rotatable design of the noise elimination vanes can lead the module to automatically regulate the ventilation angle of the noise elimination vanes according to different travelling directions of vehicles, thus achieving the best noise elimination and pressure leakage effects.

The invention discloses construction technology for a soft rock large-deformation tunnel by a de-stressing method and a matched bracket, and belongs to a high-burial depth large-deformation soft rock tunnel method and a support. The technology comprises the following steps: 1, performing tunnel tunneling construction and tunneling; 2, constructing mesh beam and shotcrete supports of the tunnel; 3, excavating a bottom plate de-stressing groove backwards from the tunneled working surface at the tunneled tunnel bottom plate; 4, constructing a tunnel wall de-stressing groove at the wall position of the tunnel; 5, setting up the matched bracket from the rear to the front; and 6, concreting at the bottom plate of the tunnel. The construction technology has the advantages that: 1, the de-stressing groove is excavated at a bottom groove, so that the tunnel is positioned in a low stress region at the initial stage of the excavation and the influence on and damage to the tunnel due to high stress are reduced after the tunnel excavation; 2, an enclosed structure where a full section and the tunnel section are adapted has high deformation resistance; 3, the bracket has a multi-stage variable bearing structure, and can prolong the time in the tunnel; and 4, an intensity-controlled buffer cushion block controls the variation rate of the bracket timely. In addition, the construction technology also has the advantages of simple structure and strong engineering practicability.

The invention provides an omnibearing pressure relief method for a thick coal seam working face rock burst danger roadway and relates to the technical field of rock burst danger prevention and control. The method is mainly applied to a thick coal seam working face and specifically comprises the steps that when the roadway is tunneled to a rock burst danger area, the pressure relief manner and pressure relief parameters are determined according to mining conditions and geological conditions; cut joints are constructed on a top plate for pressure relief, drilled holes are constructed on a bottomplate for water injection softening, large-diameter drilled holes are constructed on two walls of the roadway for pressure relief, and a barrel-shaped pressure relief zone is formed; and the stress state of surrounding rock of the roadway is determined, and it is guaranteed that a peak stress area is located outside a supporting range. According to the pressure relief method, the barrel-shaped weakening zone can be formed within a certain range of the surrounding rock of the roadway, so that high stress in the surrounding rock of the roadway is transferred to the deep portion, and then it isguaranteed that the surrounding rock of the roadway is located at low stress; and when impacts happen, the barrel-shaped area can bear overall stress, coal is prevented from protruding, a wedge-shapedresistance zone is generated, and therefore rock burst danger is prevented from happening.

The invention discloses a construction method for drilling a depressurization hole in a gob-side mining roadway. The construction method comprises the main steps that (1), drilling sampling is conducted in a coal side where a haulage gate of a first coal mining face is not influenced by mining; (2), drilling sampling is conducted on the side, close to a coal mining face and away from a base plate by 1.5 m in height, of the next coal mining face gob-side mining roadway; (3) according to the two drilling sampling processes, the corresponding rule of the drilling depth and the pulverized coal quality value is found out, and the lateral bearing pressure distribution rule of the side, close to the coal mining face, of the gob-side mining roadway is obtained; (4), the stepped depressurization hole is drilled in an area from the front side of the coal mining face to a stopping line along the roadway by reference to the obtained lateral bearing pressure distribution rule; and (5), construction in the next coal mining face gob-side mining roadway is continuously conducted, and the construction steps are repeated till construction is completed. The construction method for drilling the depressurization hole in the gob-side mining roadway has the characteristics of being small in disturbance on the gob-side mining roadway, good in depressurization effect, small in construction difficulty, high in operability, short in construction period, low in construction cost and the like.

The invention discloses a bottom plate pressure relief and reinforcement structure for controlling a floor heave of a deep roadway and a construction method of the bottom plate pressure relief and reinforcement structure. The construction method comprises the following steps: (1) excavation of a roadway and anchor mesh supporting: excavating the deep roadway, and performing the anchor mesh supporting on a surrounding rock after the surrounding rock is formed; and (2) digging of two pressure relief troughs: respectively digging a long-strip-type pressure relief trough in each of the left and right sides of a bottom plate of the roadway through an air pick along the axial direction of the roadway, wherein the cross section of each pressure relief trough is rectangular, and the pressure relief troughs take a boundary line of one side end as a symmetric line. In conclusion, a bottom plate pressure relief method is used for controlling the problems of the floor heave of the deep roadway and deformation of the surrounding rock; and on the basis of a deep roadway anchor and injection supporting technology at the present, the pressure relief effect on the surrounding rocks on the bottom plate, two ends and a top plate is improved by reasonably determining the shape, the size and the arrangement position of each pressure relief trough, the number of secondary interstices in the surrounding rocks is increased, the grouting effect on the surrounding rocks is enhanced, the problem of the floor heave of the deep roadway can be effectively controlled, and long-term stability of the surrounding rock of the deep roadway is guaranteed.

The invention discloses a water-conducting and pressure-releasing type composite well wall of a vertical shaft and a construction method thereof. The composite wall comprises an inner wall, a waterproof interlayer and an outer wall, wherein a circle of water-conducting groove is pre-buried in the inner wall at the height of each seepage layer; each water-conducting is a circle of enclosed pipeline, and the periphery of the pipeline is provided with a plurality of water-conducting holes; and the inner cavities of all water-conducting grooves are communicated by water-conducting pipes from top to bottom, and the bottom of each water-conducting pipe extends from the bottom of a shaft. Therefore, seepage water between the inner wall and the outer wall is conducted out. The invention has the advantages that formation water infiltrating the sandwich from the outer wall firstly flows in the water-conducting groove through the water-conducting holes and then is conducted to the bottom of the shaft through the water-conducting pipes to decrease the water head height and reduce the water pressure. Therefore, the thickness of the wall is reduced, investment is saved, and the problem of seepage caused by wall thawing after freezing sinking is solved.

The invention discloses a drilling pressure relief control method of a longwall-face mining roadway with deformed forepole support sections and belongs to drilling pressure relief control method for roadway deformation. Softening of surrounding rocks of the mining roadway due to forepole support pressure of a longwall face lowers the control effect of forepole support. According to features of dynamic traction of the mining face, pressure-relief boreholes are constructed by adopting an auger drill miner, stress of shallow surrounding rocks is lowered, and control difficulty brought by stress softening of high surrounding rocks of the roadway is alleviated. The technical scheme includes that three-hole drill holes are designed in the roadway, horizontal and vertical distance between the depth of the drill holes and the neighboring drill holes is determined according to section size of the roadway and physical and mechanical parameters of a coal body, an auger mining production system is arranged in the roadway, pressure-relief boreholes are constructed in areas close to forepole support pressure affection area, and drilling equipment is moved forward continuously with advancing of the working face. By the arrangement, the control effect of the forepole support of the working face is favorably improved, labor intensity is lowered, and production efficiency of the working face is improved.

An anchor rod includes a sleeve open at one end and having a blocking plate at the other end; a pressure relief pipe fixedly arranged on an inner wall of the sleeve; and a rod body. A guide hole is formed in a center of the blocking plate. A part of the rod body penetrates through the guide hole and extends into the sleeve. A gap is formed between the pressure relief pipe and the blocking plate. An overflow valve is connected to the pressure relief pipe. A piston in sliding seal fit with the sleeve and the pressure relief pipe is arranged at the rod body. A sealing ring in sliding seal fit with the rod body is arranged at the inner wall of the guide hole; and a sealing cavity between the blocking plate and the piston in the sleeve is filled with emulsion.

The invention relates to the technical field of PV valves, and discloses a PV valve for a ballast tank. The PV valve for the ballast tank comprises a vacuum pressure relief rod, a lifting bolt is arranged on the outer side of the vacuum pressure relief rod, a shell is arranged at the lower end of the lifting bolt, a floater is arranged inside the shell, a pressure valve disc guide seat is arrangedat the lower end of the floater, a pressure spring is arranged between the pressure valve disc guide seat and the floater, and a pressure valve disc body is arranged at the lower end of the pressurevalve disc guide seat. The PV valve for the ballast tank has the advantages that pressure relief can be conveniently completed when the air pressure in the ballast tank is too high and needs to be released outwards, meanwhile, pressurization in the ballast tank can be conveniently completed when the air pressure in the ballast tank is too low and needs to be increased inwards, water can be prevented from entering the ballast tank when the water pressure in the ballast tank is too high, the problem that when vacuum pressure in the ballast tank needs to be discharged, discharging is inconvenientis solved, and a better using prospect can be brought.

The invention discloses a rock burst preventing method for a blast and injection of water-coupled softened coal body, and is suitable for rock burst disaster prevention of coal mining, and in particular to rock burst prevention of a tight and hard coal bed which is hard to inject water to soften. The method disclosed by the invention comprises the following steps: firstly, constructing water injection holes and blast holes in a coal wall of a lane, wherein the water injection holes and the blast holes are alternately formed, that is, the blast holes are formed between two adjacent water injection holes; then performing loose blasting on the coal body through the blast holes to relieve the pressure of the coal body and form blast gaps in the coal body; and then injecting water into the coal body in the water injection holes to soften the coal body. Gaps are distributed by taking the blast holes as the center in coal body blast, so that the water injection property of the coal body is increased. After blast, the coal body is injected with water, so that the water injection resistance is reduced and the water injection rate is increased; the coal bed which is originally hard to inject water, or even is hardly injected with water to soften, is injected with water to soften, so that the rock burst disaster is effectively prevented. The method is simple to operate, safe and practical and good in pressure relieving effect.

The invention discloses an armoured central alternating-current closed metal switch cabinet which comprises a cabinet body. A cable chamber and a component cavity are arranged in the cabinet body. The cable chamber is arranged on one side of the component cavity, a bus chamber is arranged inside the cable chamber and close to the top of the cabinet body, an instrument chamber, a breaker chamber and an observation room are sequentially arranged in the component cavity from top to bottom, and a first pressure release channel, a second pressure release channel and a third pressure release channel are arranged at the top of the cabinet body, wherein the first pressure release channel is communicated with the cable chamber and used for conducting pressure releasing on the cable chamber, the second pressure release channel is communicated with the bus chamber and used for conducting pressure release on the bus chamber, and the third pressure release channel is communicate with the breaker chamber and used for conducting pressure release on the breaker chamber. Due to the fact that the pressure release channels which are communicated with the breaker chamber, the bus chamber and the cable chamber respectively are arranged at the top of the cabinet body, internal pressure can be released as quickly as possible when the switch cabinet breaks down. Thus, it is guaranteed that the switch cabinet is not damaged, and meanwhile, the working safety of an operator is also guaranteed.

The invention relates to the technical field of air conditioners, and particularly provides a control method of a magnetic suspension air conditioning unit. The technical problem of low pressure relief speed of an existing control method is solved. A pressure relief bypass of the magnetic suspension air conditioning unit comprises a pressure relief switch valve and a pressure relief throttling element which are arranged in parallel. The control method comprises the steps that when the unit meets the shutdown condition, the current pressure ratio of a compressor is obtained; the current pressure ratio is compared with an allowable shutdown pressure ratio threshold value; and according to the comparison result, the compressor is selectively and directly controlled to stop or the pressure relief switch valve and the pressure relief throttling element are opened to adjust the pressure ratio until the compressor stop condition is met. According to the magnetic suspension air conditioning unit, the throttling and pressure reducing functions of the throttling element can be utilized, the switching value characteristic of the pressure relief switch valve can be utilized, the instantaneous pressure relief effect is obvious after the pressure relief switch valve is switched on, the pressure ratio rapidly reaches the allowable shutdown pressure ratio threshold value of the compressor, which is particularly important for emergency failure unloading shutdown, and the risk of bearing damage of the magnetic suspension centrifugal compressor is reduced.

The invention discloses a battery module. The battery module comprises a box body module, a battery cell module and a sealing module. A mounting cavity is formed in the box body module; the box body module comprises a top sealing plate, and a plurality of first explosion-proof valves are arranged on the top sealing plate; the battery cell module is arranged in the mounting cavity; the battery cellmodule comprises a plurality of battery cells, and second explosion-proof valves, positive plates and negative plates of the battery cells are all located at the tops of the battery cells; the sealing module comprises a plurality of first heat insulation plates and a plurality of second heat insulation plates; each first heat insulation plate and each second heat insulation plate are bonded between two adjacent battery cells to divide the mounting cavity into a plurality of sub-mounting cavities which are arranged in a transverse manner; the plurality of sub-mounting cavities are in one-to-one correspondence with the plurality of first explosion-proof valves; each sub-mounting cavity is suitable for being sealed by a sealant after being communicated with the corresponding first explosion-proof valve; and at least one battery cell is suitable for being mounted in each sub-mounting cavity. According to the embodiment of the invention, the battery module is good in sealing performance, can better release pressure to protect the battery cells, and is high in safety.

The invention discloses a topping method in the small coal pillar exploitation technology. The topping method includes the following steps that firstly, the overlying strata performance and the occurrence state of a certain roadway top plate are systematically analyzed according to a certain roadway early borehole columnar section provided by a mine party and a columnar section acquired in recentborehole detection, and multiple cutting positions are selected out; analysis of each cutting position on the stability of the certain roadway top plate and the stability of an adjacent roadway coal pillar is analyzed through theoretical calculation of the stability of the roadway top plate and the stability of the roadway coal pillar, and the cutting position is determined; and after the cuttingposition is determined, a KLJ7 chain arm topping machine is used for carrying out cutting along a determined cutting path. The cutting position of the roadway top plate is scientifically determined, equipment is reasonably operated, by means of a mechanical topping manner, cut seams are straight, cutting surfaces are smooth, and the unloading effect is ideal. By means of the topping manner, the problems that during exploding pre-splitting, cracks are obstructed, the cracks are twisted, and the caving resistance of the top plate is large are solved.

The invention relates to a screw excited hydraulic harmonic high-power enhancement vibrator, and belongs to the technical field of petroleum and natural gas extraction downhole tools. The vibrator comprises a vibrator body and a screw power short joint. The vibrator body is composed of a vibrator shell, a screw rotor head, a fixed closure block and a resonance enhancement part. The fixed closure block is mounted in the vibrator shell, and the resonance enhancement part is mounted below the fixed closure block. The screw rotor head is mounted above the fixed closure block. By means of the vibrator, wear and resistance reduction between a drill rod and the well wall can be achieved, high-pressure well drilling fluid completing impacting on a screw rotor enters the resonance enhancement part,and therefore the Helmholtz effect is formed, the pulsation effect of the high-pressure well drilling fluid is enhanced and amplified with high power, pipe bundle wriggling is caused by axial pulsation generated by the above process, the pressure transmission efficiency is higher by means of double force cooperation, and the back pressure relief effect is better. The problem that due to the structure of an existing hydraulic vibrator, friction and resistance and back pressure existing between the drill rod and the well wall cannot be solved thoroughly is solved.

The invention relates to an explosion-proof, waterproof and breathable valve, which comprises a valve body, a cover body, a waterproof and breathable film, and an elastic dome. A sliding ring assembly is set in the chamber, and a pressure relief hole is arranged on the side wall of the valve body or the cover body. , a waterproof rubber ring is fixed on the end face of the sliding ring assembly. The waterproof and gas-permeable membrane of the present invention will not be punctured, and the waterproof and gas-permeable membrane returns to a normal state after the excessive internal pressure is released. At the same time, since the dome is used as the elastic part for the position restoration of the internal components, the sensitivity and smoothness of the waterproof and breathable membrane, the main ring, the pressure ring and the inner ring in the process of moving outwards under the pressure of the internal pressure of the equipment are improved, ensuring The inside of the device and the pressure relief hole can be accurately connected to realize the release of pressure, which is safer and more reliable. The entire valve can be designed to be thinner and smaller, and it is more convenient to apply to equipment with limited installation space and high installation requirements.

The invention provides a peristaltic pump head, belongs to the technical field of peristaltic pumps, and solves the problems that an existing peristaltic pump is bad in hose locating effect and poor in pressure relief effect. The peristaltic pump head comprises a pump body and a main shaft; the pump body is internally provided with a pump cavity; the main shaft is arranged in the pump cavity in apenetrating manner along the front-and-back direction of the pump body; a plurality of rollers annularly distributed uniformly are arranged on the main shaft; clamping holes are separately formed in the left side and the right side of the pump cavity; a hose penetrates into the pump cavity via one clamping hole and then extends out of the another clamping hole in a penetrating manner; a cylindrical surface coaxial to the main shaft is arranged at the top of the pump cavity; the hose is stuck on the cylindrical surface under the action of the rollers; a concave hole extending in the radial direction of the main shaft is formed in the cylindrical surface; a first pressure relief structure is arranged in the concave hole; and a second pressure relief structure is arranged below the hose. Theperistaltic pump head has the advantages of good pressure relief effect and good locating effect on the hose.

The invention discloses an outburst coal seam hole protecting and pressure relief combined drilling and a use method thereof. The outburst coal seam hole protecting and pressure relief combined drilling includes a spiral groove screen hole drill pipe and a special-shaped groove drill pipe, and also includes a special drill bit and a transition lap device; the special drill bit is connected to thespiral groove screen hole drill pipe; one end of the transition lap device is connected to the spiral groove screen hole drill pipe, and the other end is connected to the special-shaped groove drill pipe; and the special drill bit, the transition lap device, the spiral groove screen hole drill pipe and the special-shaped groove drill pipe are coaxially distributed. In the invention, the spiral groove screen hole drill pipe and the special-shaped groove drill pipe are used, and the arranged special drill bit and the transition lap device are used for forming the combined drill tool, which can achieve a better hole protecting and pressure relief effect during the drilling operation, and is convenient to collect gas and coal dust at the borehole opening; the structural combination is convenient; and the flexibility of the drilling operation is improved.

The invention discloses a multifunctional integrated solenoid valve. The multifunctional integrated solenoid valve comprises a solenoid valve body, a solenoid valve cover, a water inlet, a combinationcoil, a return spring, a movable iron core, front surface membrane and an anti-blocking spring; a water outlet end of the solenoid valve body is connected with a constant-pressure constant-flow device; a water outlet end of the constant-pressure constant-flow device is connected with a vacuum breaker; a flow sensor is arranged between the solenoid valve body and the constant-pressure constant-flow device; the vacuum breaker comprises a shell and a water outlet; a cover is arranged at the top of the shell; a safe pressure relief sealing assembly which moves up and down is arranged between theshell and the cover; the safe pressure relief sealing assembly comprises an inner plug rod, a supporting sleeve, a safe pressure relief spring, a broken opening positioning ring, a check membrane anda vacuum breaking membrane; and a safe pressure relief opening is formed in the cover. The multifunctional integrated solenoid valve has a compact structure, convenience and reliability in assemblingand high operating stability, so that the functions are complete and the performance is ensured; moreover, the vacuum breaker is more concise in assembling; a positioning effect is good; and a safe pressure relief effect and a siphon preventing effect are better.

The invention discloses a continuous pressure-relief deslagging system and a continuous pressure-relief deslagging method of a liquid-state pressure-boosting deslagging gasifier, and is used for solving the problems that an existing deslagging system is complex in technical process, complicated to operate, high in equipment investment and poor in reliability. The method comprises the following steps: carrying out water-bath chilling on high-temperature and high-pressure slags which are generated by the pressure-boosting gasifier and fall into the bottom of the pressure-boosting gasifier; then feeding the high-temperature and high-pressure slags into a slag crusher for crushing, wherein the crushed high-pressure slags flow into a pressure-reducing pipe along with water; further carrying out pressure reduction on a mixture which contains high-pressure gas and a small amount of fine slag water and is generated when a slag-water mixture passes through the pressure-reducing pipe for pressure relief; then sending the slag-water into a gas discharging tank and carrying out washing and gas-liquid separation; feeding the slag-water mixture subjected to pressure relief into a slag collecting tank; and finally, discharging into a slag conveyor, wherein the discharging gas at the top of the inside of the gas discharging tank is sent to a torch while the slag water at the bottom of the inside of the gas discharging tank is sent into the slag collecting tank. The method disclosed by the invention is simple and reliable in process, flexible, simple and convenient to operate and low in running cost, and realizes energy conservation and consumption reduction. The system disclosed by the invention is simple, low in equipment investment, high in reliability and long in service life.

The invention provides a pressure-limiting valve device and a pressure cooker; the pressure-limiting valve device comprises a valve body and a position assembly, wherein a first channel suitable for being communicated with the inner part of the pot body and a cavity communicated with the first channel are formed in the valve body; a second channel communicated with the cavity is formed in the valve body, and the outlet of the second channel is formed in the top surface of the valve body and faces upwards; the piston assembly is movably arranged in the cavity and has a first position enabling the first channel to be communicated with the second channel, and a second position enabling the first channel to be disconnected from the second channel; the piston assembly is arranged in the valve body and cannot be removed from the valve body; and due to the fact that the outlet of the second channel faces upwards, air cannot blow to a person, so that a user is not scalded easily.

The invention discloses a pressure relief method for a short-distance overlying residual coal pillar. The method comprises the following steps that a standard test piece is prepared in a laboratory after sampling, and the width X1 of a crushing zone formed by the influence of primary mining in the coal pillar and the width X2 of a crushing zone formed by the influence of secondary mining in the coal pillar are determined; a hole is drilled upwards in the roadside on the side, close to the coal pillar, of an underlying coal seam roadway on the site, an explosive is filled in the hole for blasting, as the shape of the cross section of the remaining part of the coal pillar approximates to a parallelogram, through the instability quality of the parallelogram, the coal pillar is further damagedunder the action of concentrated load of a top plate, the whole coal pillar loses the stress transmission capability, pressure relief is further realized, and the coal mining face is guaranteed to bemined under a low-stress state. The pressure relief method for the short-distance overlying residual coal pillar has the advantages of scientific principle, reasonable design, strong pertinence, convenient operation, high efficiency, high safety and reliability and good pressure relief effect by adopting the operation mode of combining theory with practice.

The invention discloses a method for optimizing a roadway area stress field in construction outside a roadway, and belongs to the technical field of roadway support. The method comprises the following steps of firstly excavating a relieving roadway at a proper location in the floor strata of a pre-excavated roadway, testing ground stress in a roadway communicated with the pre-excavated roadway, and finding the position with a maximum principal stress difference of roadway sides after roadway excavation through calculation and analysis; constructing multiple rows of stress optimization drill holes in the relieving roadway towards the position with the maximum principal stress difference, and implementing static blasting in the position of the maximum principal stress difference so as to optimize the roadway area stress field. By applying the method, a high stress roadway having no condition of a pressure relieving scheme for construction inside the roadway can be subjected to pressure relieving and roadway area stress field optimization; the method is simple, convenient to operate, good in application effect and bright in application prospect.

The invention relates to the field of winding pipe production equipment, in particular to PP winding pipe production equipment with a braking component. The PP winding pipe production equipment comprises a diameter adjusting structure, a first stretching and contracting structure, a second stretching and contracting structure, a guiding structure, a braking structure and a lubricating structure, wherein use of the diameter adjusting structure facilitates to adjust the position of the first stretching and contracting structure rapidly, meanwhile, a bolt of the adjusting position is avoided frombeing subjected to force directly, and the position adjusting efficiency and quality of the first stretching and contracting structure are greatly improved; by means of the arrangement of the brakingstructure, the pressure on cooling water is reduced, the cooling water is made to be poured on the guiding structure better, the water pouring amount is increased, splashing of the cooling water on arubber strip is effectively avoided at the same time, and the rubber strip is avoided from being pasted to the guiding structure; and the lubricating structure is arranged at the end portion of the second stretching and contracting structure and is connected to the braking structure, the use of the lubricating structure facilitates resetting of the braking structure, and by means of the use of the braking structure, the fact that the lubricating structure is driven to lubricate the guiding structure while the cooling water is sprayed is facilitated.