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<\/figure>\n\n\n\n\ud83d\udcd8 DGMS (Tech.)(S&T) Circular No. 02\/2025<\/mark><\/strong><\/p>\n\n\n\n Issued from: Dhanbad, April 2025<\/strong> \ud83d\udd39 1. Legal Basis<\/mark><\/strong><\/p>\n\n\n\n \u26a0\ufe0f Problem:<\/strong> \ud83d\udd39 2. R&D Study (CMPDIL Ranchi)<\/strong><\/p>\n\n\n\n \ud83d\udd39 3. Recommendations<\/strong><\/p>\n\n\n\n A. Continuous Miner (CM) Panels<\/strong><\/p>\n\n\n\n B. Powered Support Longwall (PSLW) Panels<\/strong><\/p>\n\n\n\n C. General Rule for MPP (Mass Production Panel)<\/strong><\/p>\n\n\n\n \ud83d\udd39 4. Implementation<\/strong><\/p>\n\n\n\n \ud83d\udcdd Key Points for Competitive Exams<\/strong><\/p>\n\n\n\n \u2728 MCQs \u2013 DGMS Circular 02\/2025 (Ventilation at CM & Longwall Panels)<\/strong><\/p>\n\n\n\n \ud83d\udd34 Q1.<\/strong> As per DGMS Circular 02\/2025, which regulation of CMR 2017 primarily governs adequate ventilation in belowground mines? \ud83d\udd34 Q2.<\/strong> Minimum air quantity at LVC of ventilation district must be: \ud83d\udd34 Q3.<\/strong> Excessive air requirement in Mass Production Panels (MPP) may lead to: \ud83d\udd34 Q4.<\/strong> Which organization conducted the R&D project \u201cRequirement of Air in Mass Production Technology\u201d<\/em>? \ud83d\udd34 Q5.<\/strong> In Degree I & II gassy mines<\/strong>, Qmin at LVC of CM panel is given by: \ud83d\udd34 Q6.<\/strong> In Degree III gassy mines<\/strong>, Qmin at LVC of CM panel is: \ud83d\udd34 Q7.<\/strong> In formula for air quantity, Amax<\/strong> refers to: \ud83d\udd34 Q8.<\/strong> For CM panels, relative humidity should not exceed: \ud83d\udd34 Q9.<\/strong> To maintain comfortable working conditions in CM panels, temperature difference between DBT & WBT should be at least: \ud83d\udd34 Q10.<\/strong> Minimum air required at LVC of CM panels to restrict machine-induced temperature rise: \ud83d\udd34 Q11.<\/strong> For Powered Support Longwall (PSLW) panels, minimum velocity required at face: \ud83d\udd34 Q12.<\/strong> Formula for minimum air quantity in PSLW face: \ud83d\udd34 Q13.<\/strong> Minimum air required in PSLW panels to control heat rise due to machines: \ud83d\udd34 Q14.<\/strong> In MPP, how should the minimum air requirement be determined? \ud83d\udd34 Q15.<\/strong> Ventilation scheme after commencement of MPP must be prepared as per: \ud83d\udd34 Q16.<\/strong> Excessive rise in water gauge at ventilator is a direct result of: \ud83d\udd34 Q17.<\/strong> DBT stands for: \ud83d\udd34 Q18.<\/strong> WBT stands for: \ud83d\udd34 Q19.<\/strong> The workshop on ventilation requirements was organized at: \ud83d\udd34 Q20.<\/strong> The Circular 02\/2025 is applicable to: \ud83d\udcd8 DGMS (Tech.)(S&T) Circular No. 02\/2025 Issued from: Dhanbad, April 2025Subject: Guidelines on Minimum Air Quantity required at Continuous Miner (CM) and Longwall (PSLW) Panels \ud83d\udd39 1. Legal Basis \u26a0\ufe0f Problem:In Mass Production Panels (MPP), high daily output requires very large air quantity \u2192 causes: \ud83d\udd39 2. R&D Study (CMPDIL Ranchi) \ud83d\udd39 3. Recommendations A. … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":104,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[45,46,40,17,44,49,43,18,25,19,32,48,39,14,42,41,37,47,38],"class_list":["post-102","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dgms-circular","tag-air-quantity-in-mines","tag-cmpdil-ranchi","tag-cmr-2017-regulation-153","tag-coal-mines-regulations-2017","tag-continuous-miner-panel-ventilation","tag-dbt-wbt-temperature","tag-dgms-circular-02-2025","tag-dgms-circular-2025","tag-dgms-exam","tag-dgms-mcq","tag-dgms-study-material","tag-longwall-panel-ventilation","tag-mass-production-panels","tag-mine-safety","tag-mine-ventilation-standards","tag-mineportal","tag-onlineminingexam","tag-relative-humidity-in-mines","tag-ventilation-in-mines"],"_links":{"self":[{"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/posts\/102","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/comments?post=102"}],"version-history":[{"count":2,"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/posts\/102\/revisions"}],"predecessor-version":[{"id":105,"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/posts\/102\/revisions\/105"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/media\/104"}],"wp:attachment":[{"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/media?parent=102"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/categories?post=102"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dgmsexam.com\/studymaterial\/wp-json\/wp\/v2\/tags?post=102"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/mark>Subject: Guidelines on Minimum Air Quantity required at Continuous Miner (CM) and Longwall (PSLW) Panels<\/strong><\/p>\n\n\n\n
\n\n\n\n\n
Mine management must provide adequate ventilation to:\n\n
Ventilation district must have:\n\n
In Mass Production Panels (MPP), high daily output requires very large air quantity \u2192 causes:<\/p>\n\n\n\n\n
\n\n\n\n\n
\n
\n\n\n\n\n
\n
Qmin = 3 \u00d7 Amax \u00d7 0.5 m\/s<\/li>\n\n\n\n
Qmin = 3 \u00d7 Amax \u00d7 0.75 m\/s<\/li>\n\n\n\n\n
\u279d At least 25 m\u00b3\/s air<\/strong> at LVC<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
\n\n\n\n\n
\n
\n
\u279d At least 60 m\u00b3\/s air<\/strong><\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
\n\n\n\n\n
\n\n\n\n\n
\n\n\n\n\n
\n
\n
\n
\n\n\n\n
\n\n\n\n
A) Reg. 142
B) Reg. 153
C) Reg. 160
D) Reg. 170
E) Reg. 183
\u2705 Answer: B) Reg. 153<\/strong>
\ud83d\udc49 Explanation: Circular is based on Reg. 153(1) & 153(2) of CMR 2017 regarding ventilation requirements.<\/p>\n\n\n\n
\n\n\n\n
A) 4 m\u00b3\/min\/person or 2.0 m\u00b3\/min\/tonne output
B) 6 m\u00b3\/min\/person or 2.5 m\u00b3\/min\/tonne output
C) 5 m\u00b3\/min\/person or 3.0 m\u00b3\/min\/tonne output
D) 8 m\u00b3\/min\/person or 2.5 m\u00b3\/min\/tonne output
E) 6 m\u00b3\/min\/person only
\u2705 Answer: B) 6 m\u00b3\/min\/person or 2.5 m\u00b3\/min\/tonne output<\/strong>
\ud83d\udc49 Explanation: Regulation 153(2)(a), CMR 2017.<\/p>\n\n\n\n
\n\n\n\n
A) Reduced dust concentration
B) Higher ventilation pressure and risk of spontaneous heating
C) Decrease in water gauge
D) Elimination of humidity issues
E) Reduced machine heat generation
\u2705 Answer: B) Higher ventilation pressure and risk of spontaneous heating<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) NIRM KGF
B) IIT-ISM Dhanbad
C) CMPDIL Ranchi
D) CIMFR Dhanbad
E) DGMS Dhanbad
\u2705 Answer: C) CMPDIL Ranchi<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Qmin = 3 \u00d7 Amax \u00d7 0.25 m\/s
B) Qmin = 3 \u00d7 Amax \u00d7 0.5 m\/s
C) Qmin = 3 \u00d7 Amax \u00d7 0.75 m\/s
D) Qmin = 2 \u00d7 Amax \u00d7 0.5 m\/s
E) Qmin = Amax \u00d7 1.0 m\/s
\u2705 Answer: B) 3 \u00d7 Amax \u00d7 0.5 m\/s<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) 3 \u00d7 Amax \u00d7 0.25 m\/s
B) 3 \u00d7 Amax \u00d7 0.5 m\/s
C) 3 \u00d7 Amax \u00d7 0.75 m\/s
D) 2 \u00d7 Amax \u00d7 0.75 m\/s
E) 2.5 \u00d7 Amax \u00d7 1.0 m\/s
\u2705 Answer: C) 3 \u00d7 Amax \u00d7 0.75 m\/s<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Maximum production capacity
B) Gallery cross-sectional area (m\u00b2)
C) Longwall face length (m)
D) Height of coal seam
E) Quantity of coal produced per shift
\u2705 Answer: B) Gallery cross-sectional area (m\u00b2)<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) 60%
B) 65%
C) 75%
D) 80%
E) 85%
\u2705 Answer: D) 80%<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) 1\u00b0C
B) 1.5\u00b0C
C) 2\u00b0C
D) 3\u00b0C
E) 5\u00b0C
\u2705 Answer: C) 2\u00b0C<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) 10 m\u00b3\/s
B) 15 m\u00b3\/s
C) 20 m\u00b3\/s
D) 25 m\u00b3\/s
E) 30 m\u00b3\/s
\u2705 Answer: D) 25 m\u00b3\/s<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) 1.5 m\/s
B) 2.0 m\/s
C) 2.5 m\/s
D) 3.0 m\/s
E) 3.5 m\/s
\u2705 Answer: D) 3.0 m\/s<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Qmin = Area \u00d7 2.0 m\/s
B) Qmin = Area \u00d7 2.5 m\/s
C) Qmin = Area \u00d7 3.0 m\/s
D) Qmin = Area \u00d7 3.5 m\/s
E) Qmin = Area \u00d7 4.0 m\/s
\u2705 Answer: C) Area \u00d7 3.0 m\/s<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) 30 m\u00b3\/s
B) 40 m\u00b3\/s
C) 50 m\u00b3\/s
D) 60 m\u00b3\/s
E) 70 m\u00b3\/s
\u2705 Answer: D) 60 m\u00b3\/s<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) By average of CM & PSLW values
B) By considering CM panel only
C) By considering PSLW panel only
D) By selecting the highest among all criteria
E) By DGMS standard fixed value
\u2705 Answer: D) By selecting the highest among all criteria<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Reg. 144 of CMR 2017
B) Reg. 153(2) of CMR 2017
C) Reg. 160 of CMR 2017
D) Reg. 170 of CMR 2017
E) Reg. 175 of CMR 2017
\u2705 Answer: B) Reg. 153(2) of CMR 2017<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Low air delivery
B) High air quantity supply in LVC
C) Short circuiting of air
D) Blower failure
E) Dust suppression system
\u2705 Answer: B) High air quantity supply in LVC<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Dry Bulb Thermometer
B) Dry Base Temperature
C) Dust Bulb Test
D) Dry Barometer Temperature
E) Direct Base Temperature
\u2705 Answer: A) Dry Bulb Thermometer<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Wet Bulb Thermometer
B) Wet Base Temperature
C) Water Base Thermostat
D) Warm Bulb Test
E) Wet Barometer Temperature
\u2705 Answer: A) Wet Bulb Thermometer<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) CMPDIL Ranchi HQ
B) IIT ISM Dhanbad
C) Jhanjra Project, ECL
D) NCL Singrauli
E) SECL Korba
\u2705 Answer: C) Jhanjra Project, ECL<\/strong><\/p>\n\n\n\n
\n\n\n\n
A) Only Degree III coal mines
B) Only metalliferous mines
C) All coal mines using CM and PSLW panels
D) Only opencast coal mines
E) Only fire-area blasting panels
\u2705 Answer: C) All coal mines using CM and PSLW panels<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"