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    Hi Valery,<br>
    <br>
    Have you looked at this scenario? Fan stops running during run. This
    would result in an increased pressure in the electronics box. The
    increased pressure increases the leak rate of cooling air into the
    RICH detector volume. Depending on the severity of the leak,
    pressure in the RICH gas volume may increase until the cooling
    system is turned off. The O2 concentration will increase until the
    cooling flow stops. The O2 contamination then absorbs the light
    until it is removed via N2 purge. <br>
    <br>
    There is, of course,  a worse case scenario, depending on how high
    the pressure in the electronics box goes. Since final pressure is
    unknown, it may or may not be a realistic failure mode.<br>
    <br>
    So, perhaps a good question to answer would be; What are the
    advantages of using the fan vs consequences of fan failure. Is
    adding a fan a good solution to your problem or does it potentially
    create another problem?<br>
    <br>
    George<br>
    <br>
    <div class="moz-cite-prefix">On 10/17/2017 6:25 PM, Valery
      Kubarovsky wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:1153823874.2051.1508279144281.JavaMail.zimbra@jlab.org">
      <div style="font-family: arial,helvetica,sans-serif; font-size:
        12pt; color: #000000">
        <div>Hi George,</div>
        <div>Thank you for looking to all these issues. I agree that we
          have to determine the exact location of these fans in the
          Hall-B and determine the change in the length of the exhaust
          tubes.</div>
        <div><br data-mce-bogus="1">
        </div>
        <div>And sure we will test  the <span style="color: rgb(0, 0,
            0); font-family: -webkit-standard; font-size:
            16.520000457763672px; font-style: normal; font-variant-caps:
            normal; font-weight: normal; letter-spacing: normal;
            orphans: auto; text-align: start; text-indent: 0px;
            text-transform: none; white-space: normal; widows: auto;
            word-spacing: 0px; -webkit-text-size-adjust: auto;
            -webkit-text-stroke-width: 0px; background-color: rgb(255,
            255, 255); display: inline !important; float: none;"
            data-mce-style="color: #000000; font-family:
            -webkit-standard; font-size: 16.520000457763672px;
            font-style: normal; font-variant-caps: normal; font-weight:
            normal; letter-spacing: normal; orphans: auto; text-align:
            start; text-indent: 0px; text-transform: none; white-space:
            normal; widows: auto; word-spacing: 0px;
            -webkit-text-size-adjust: auto; -webkit-text-stroke-width:
            0px; background-color: #ffffff; display: inline !important;
            float: none;">exhaust line pressure when the fans will be on
            and off.</span></div>
        <div><span style="color: rgb(0, 0, 0); font-family:
            -webkit-standard; font-size: 16.520000457763672px;
            font-style: normal; font-variant-caps: normal; font-weight:
            normal; letter-spacing: normal; orphans: auto; text-align:
            start; text-indent: 0px; text-transform: none; white-space:
            normal; widows: auto; word-spacing: 0px;
            -webkit-text-size-adjust: auto; -webkit-text-stroke-width:
            0px; background-color: rgb(255, 255, 255); display: inline
            !important; float: none;" data-mce-style="color: #000000;
            font-family: -webkit-standard; font-size:
            16.520000457763672px; font-style: normal; font-variant-caps:
            normal; font-weight: normal; letter-spacing: normal;
            orphans: auto; text-align: start; text-indent: 0px;
            text-transform: none; white-space: normal; widows: auto;
            word-spacing: 0px; -webkit-text-size-adjust: auto;
            -webkit-text-stroke-width: 0px; background-color: #ffffff;
            display: inline !important; float: none;"><br
              data-mce-bogus="1">
          </span></div>
        <div><font size="3" face="-webkit-standard">In any case the cRio
            interlock will monitor the temperature inside the electronic
            panel and will shut down the detecter in case of
            accident with exhaust  fans.</font></div>
        <div><br>
        </div>
        <div>Thank you again,</div>
        <div>Valery</div>
        <div><br data-mce-bogus="1">
        </div>
        <div><br data-mce-bogus="1">
        </div>
        <div><br>
        </div>
        <hr id="zwchr" data-marker="__DIVIDER__">
        <div data-marker="__HEADERS__">
          <blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"
            data-mce-style="border-left: 2px solid #1010FF; margin-left:
            5px; padding-left: 5px; color: #000; font-weight: normal;
            font-style: normal; text-decoration: none; font-family:
            Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From: </b>"George
            Jacobs" <a class="moz-txt-link-rfc2396E" href="mailto:jacobsg@jlab.org"><jacobsg@jlab.org></a><br>
            <b>To: </b>"Valery Kubarovsky" <a class="moz-txt-link-rfc2396E" href="mailto:vpk@jlab.org"><vpk@jlab.org></a><br>
            <b>Cc: </b>"Tyler Lemon" <a class="moz-txt-link-rfc2396E" href="mailto:tlemon@jlab.org"><tlemon@jlab.org></a>,
            "dsg-rich" <a class="moz-txt-link-rfc2396E" href="mailto:dsg-rich@jlab.org"><dsg-rich@jlab.org></a><br>
            <b>Sent: </b>Tuesday, October 17, 2017 5:31:52 PM<br>
            <b>Subject: </b>Re: [Dsg-rich] MVT exhaust fan in EEL 124<br>
          </blockquote>
        </div>
        <div data-marker="__QUOTED_TEXT__">
          <blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"
            data-mce-style="border-left: 2px solid #1010FF; margin-left:
            5px; padding-left: 5px; color: #000; font-weight: normal;
            font-style: normal; text-decoration: none; font-family:
            Helvetica,Arial,sans-serif; font-size: 12pt;">Hi Valery,<br>
            <br>
            Have you taken into account the length of the hose or tubing
            that must be added in order to attach the fan to the
            detector? If the overall line length must be doubled or
            tripled to reach the fan, the flow restriction from the
            tubing will also double or triple.<br>
            <br>
            If the fan stops running, the fan blades will restrict the
            gas flow at some level. Flowing gas has velocity and
            momentum, fan blades will require the gas change direction,
            loosing momentum and velocity. <br>
            <br>
            So, there will be additional flow restriction and it will
            increase the cooling air pressure in the electronics box in
            the case of fan failure. The added restriction due to the
            additional lengths of tubing or hose can be calculated. The
            additional restriction created by the fan blades can be
            physically tested by turning off the fan and monitoring the
            change in the exhaust line pressure.<br>
            <br>
            George<br>
            <br>
            <div class="moz-cite-prefix">On 10/17/2017 4:27 PM, Valery
              Kubarovsky wrote:<br>
            </div>
            <blockquote
              cite="mid:494352099.5668846.1508272051201.JavaMail.zimbra@jlab.org">
              <div style="font-family: arial,helvetica,sans-serif;
                font-size: 12pt; color: #000000"
                data-mce-style="font-family: arial,helvetica,sans-serif;
                font-size: 12pt; color: #000000;">
                <div>George,</div>
                <div><br>
                </div>
                <div>First we want to test it at the cleaning room to
                  measure the effectiveness of these fans.</div>
                <div>And later on we will use it in the hall. </div>
                <div><br>
                </div>
                <div>The design of the cooling system was done without
                  exhaust fans. In case of the power failure nothing
                  will happen with the pressure system. The fan has much
                  bigger diameter than our tubes and by this reason will
                  not block the air flow. It is completely open.</div>
                <div><br>
                </div>
                <div>Regards,</div>
                <div>Valery</div>
                <div><br>
                </div>
                <div><br>
                </div>
                <hr id="zwchr">
                <div>
                  <blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"
                    data-mce-style="border-left: 2px solid#1010FF;
                    margin-left: 5px; padding-left: 5px; color: #000;
                    font-weight: normal; font-style: normal;
                    text-decoration: none; font-family:
                    Helvetica,Arial,sans-serif; font-size: 12pt;"><b>From:
                    </b>"George Jacobs" <a
                      class="moz-txt-link-rfc2396E"
                      href="mailto:jacobsg@jlab.org" target="_blank"
                      data-mce-href="mailto:jacobsg@jlab.org"
                      moz-do-not-send="true"><jacobsg@jlab.org></a><br>
                    <b>To: </b>"Tyler Lemon" <a
                      class="moz-txt-link-rfc2396E"
                      href="mailto:tlemon@jlab.org" target="_blank"
                      data-mce-href="mailto:tlemon@jlab.org"
                      moz-do-not-send="true"><tlemon@jlab.org></a>,
                    "dsg-rich" <a class="moz-txt-link-rfc2396E"
                      href="mailto:dsg-rich@jlab.org" target="_blank"
                      data-mce-href="mailto:dsg-rich@jlab.org"
                      moz-do-not-send="true"><dsg-rich@jlab.org></a><br>
                    <b>Sent: </b>Tuesday, October 17, 2017 1:20:12 PM<br>
                    <b>Subject: </b>Re: [Dsg-rich] MVT exhaust fan in
                    EEL 124<br>
                  </blockquote>
                </div>
                <div>
                  <blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"
                    data-mce-style="border-left: 2px solid#1010FF;
                    margin-left: 5px; padding-left: 5px; color: #000;
                    font-weight: normal; font-style: normal;
                    text-decoration: none; font-family:
                    Helvetica,Arial,sans-serif; font-size: 12pt;">Would
                    this setup be used only in the clean room for
                    testing or would this be for use in the hall during
                    normal operations?<br>
                    <br>
                    If the answer is the latter, what would happen to
                    air cooling flow and pressure if the power to the
                    fans tripped off during a run? <br>
                    <br>
                    George<br>
                    <br>
                    <div class="moz-cite-prefix">On 10/17/2017 11:56 AM,
                      Tyler Lemon wrote:<br>
                    </div>
                    <blockquote
                      cite="mid:1154990717.5595054.1508255789019.JavaMail.zimbra@jlab.org">
                      <div style="font-family: times new roman,new
                        york,times,serif; font-size: 12pt; color:
                        #000000" data-mce-style="font-family: times new
                        roman,new york,times,serif; font-size: 12pt;
                        color: #000000;">
                        <div>Hello Valery,<br>
                        </div>
                        <div><br>
                        </div>
                        <div>Attached is the photo of the MVT exhaust
                          fan in use in EEL 124.<br>
                        </div>
                        <div><br>
                        </div>
                        <div>Would there be a possibility that RICH
                          would use similar fans to pull out the hot air
                          from the electronic panel?<br>
                        </div>
                        <div><br>
                        </div>
                        <div>Best regards,<br>
                        </div>
                        <div>Tyler<br>
                        </div>
                      </div>
                      <br>
                      <fieldset class="mimeAttachmentHeader"></fieldset>
                      <br>
                      <pre>_______________________________________________
Dsg-rich mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Dsg-rich@jlab.org" target="_blank" data-mce-href="mailto:Dsg-rich@jlab.org" moz-do-not-send="true">Dsg-rich@jlab.org</a>
<a class="moz-txt-link-freetext" href="https://mailman.jlab.org/mailman/listinfo/dsg-rich" target="_blank" data-mce-href="https://mailman.jlab.org/mailman/listinfo/dsg-rich" moz-do-not-send="true">https://mailman.jlab.org/mailman/listinfo/dsg-rich</a>
</pre>
                    </blockquote>
                    <br>
                    <pre class="moz-signature">-- 
George Jacobs
Jefferson Lab (TJNAF)
STE 12
12000 Jefferson Ave.
Newport News, VA 23606

(office) 757-269-7115

(cell)   757-876-0480

(email) <a class="moz-txt-link-abbreviated" href="mailto:jacobsg@jlab.org" target="_blank" data-mce-href="mailto:jacobsg@jlab.org" moz-do-not-send="true">jacobsg@jlab.org</a>

(website) <a class="moz-txt-link-freetext" href="https://userweb.jlab.org/%7Ejacobsg" target="_blank" data-mce-href="https://userweb.jlab.org/%7Ejacobsg" moz-do-not-send="true">https://userweb.jlab.org/~jacobsg</a></pre>
                    <br>
                    _______________________________________________<br>
                    Dsg-rich mailing list<br>
                    <a class="moz-txt-link-abbreviated"
                      href="mailto:Dsg-rich@jlab.org" target="_blank"
                      data-mce-href="mailto:Dsg-rich@jlab.org"
                      moz-do-not-send="true">Dsg-rich@jlab.org</a><br>
                    <a class="moz-txt-link-freetext"
                      href="https://mailman.jlab.org/mailman/listinfo/dsg-rich"
                      target="_blank"
                      data-mce-href="https://mailman.jlab.org/mailman/listinfo/dsg-rich"
                      moz-do-not-send="true">https://mailman.jlab.org/mailman/listinfo/dsg-rich</a><br>
                  </blockquote>
                </div>
              </div>
            </blockquote>
            <br>
            <pre class="moz-signature">-- 
George Jacobs
Jefferson Lab (TJNAF)
STE 12
12000 Jefferson Ave.
Newport News, VA 23606

(office) 757-269-7115

(cell)   757-876-0480

(email) <a class="moz-txt-link-abbreviated" href="mailto:jacobsg@jlab.org" target="_blank" data-mce-href="mailto:jacobsg@jlab.org" moz-do-not-send="true">jacobsg@jlab.org</a>

(website) <a class="moz-txt-link-freetext" href="https://userweb.jlab.org/%7Ejacobsg" target="_blank" data-mce-href="https://userweb.jlab.org/~jacobsg" moz-do-not-send="true">https://userweb.jlab.org/~jacobsg</a></pre>
            <br>
          </blockquote>
        </div>
      </div>
    </blockquote>
    <br>
    <pre class="moz-signature" cols="72">-- 
George Jacobs
Jefferson Lab (TJNAF)
STE 12
12000 Jefferson Ave.
Newport News, VA 23606

(office) 757-269-7115

(cell)   757-876-0480

(email) <a class="moz-txt-link-abbreviated" href="mailto:jacobsg@jlab.org">jacobsg@jlab.org</a>

(website) <a class="moz-txt-link-freetext" href="https://userweb.jlab.org/~jacobsg">https://userweb.jlab.org/~jacobsg</a></pre>
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