Evaluation of structure and variables within performance rating of hydraulically powered roof support legs with smooth roof control

Network architectures and protocols of M2M communications

“…The Smart Measurements in Homes and Non-Residential Premises model implements the latest advances in grid technology and energy conservation. Allows you to manage with high efficiency all energy and resource sensors in homes and offices, industrial premises, minimizing the consumption of heat, electricity, water, gas, as well as remotely monitor the level of consumption of these resources, manage their consumption, billing and cost optimization [10][11][12][13][14].…”

Nonimpact rock pressure regulation with energy recovery into the hydraulic system of the longwall powered support

“…A significant power fluid pressure difference in hydraulic prop head ends (thrust force) during the cycle of operations and the shifting contact of the support expansion unit with the roof when shifting with support activates cracking in adjacent roof rock in contact with the lap. These mechanical behavior sections are responsible for the negative impacts within the "powered support-roof" system that are called "static trampling of adjacent roof rock" [28].…”

“…Rock pressure is regulated with impacts, i.e. by sequential responses of the hydraulic prop pressure safety valves with transfers and large power fluid pressure drop from the hydraulic prop head ends to the drain pipe of the complex or onto the ground [28,29].…”

Development of Powered Support Hydraulic Legs with Improved Performance

“…To reduce the intensity of dynamic manifestations of rock pressure, special devices of the active type are used to support the face, which balance the distribution of the support resistance across the width of the supported space [10] or devices for adapting the support hydraulic system to the rock pressure level, as well as devices to reduce dynamic pressure surges in the piston cavity when the safety valve actuates [11,12].…”