200536600 九、發明說明： 【發明所屬之技術領域】 本發明係關於溶氮水之製造裝置。更爲詳細而言，本發 明是關於一種可簡單且精度良好地製造溶存氮濃度經控制 的水之溶氮水之製造裝置。 【先前技術】 從半導體用矽基板、液晶用玻璃基板、光罩用石英基板 等的電子材料表面除去微粒子等的異物，其極爲重要之點在 ® 於確保製品品質、良率。在以超音波洗淨電子材料等的情 況，可知若使用溶解有氣體的洗淨水，即可獲得良好的洗淨 效果。一般，雖希望溶存氮濃度越高越好，但若成爲過飽和 時則又將產生過剩的氣泡，此將成爲妨礙超音波傳播，或附 著於被洗淨物的表面而成爲洗淨不勻的原因。在使用內建有 振動板的噴嘴的情況，在噴嘴內部形成蓄積氣體，不僅超音 波無法傳播至水中，而且還成爲損傷超音波震盪部的原因。 爲此，需求一種在溶存氮濃度未達成過飽和之範圍內的高濃 ®度溶氣體水。 爲除去微粒子，使用溶解有氧之洗淨水的超音波洗淨最 爲有效，但從氣體操作的便利性考慮，大多使用溶解有氮的 溶氮水。作爲溶解氮於超純水之溶解手段，可舉出在水槽中 的氮沸騰術。該手段非常簡單，但以高値且精度良好地維持 溶存氮濃度有困難。又，還有使用透氣性膜模組的單純的氣 體溶解技術。若使用透氣性膜模組時，可較爲容易地獲得溶 存氮濃度高的溶氮水，但要穩定製造溶存氮濃度一定，且未 200536600 過飽和之溶氮水有困難。 相對於此，還知將超純水及氮氣供給氣體溶解裝置，由 氮濃度計測定獲得之溶氮水的溶存氮濃度，與目標氮濃度比 較，以控制供氮量的方法。但是，在依習知氮濃度計的測定 中，排放氣體對計量器的供給、試樣水的流量調整等的操作 條件的設定相當麻煩，另外，計量器係分叉設置試樣配管， 所以較爲麻煩且花費時間，必須經常排放試樣水而較爲浪 費。 Φ 在藉由脫氣處理以完全除去原水中的溶存氣體後，使用 透氣性膜模組僅供給必要量的特定氣體予以溶解，可無氣泡 產生地製造原水中溶解有指定濃度的氣體的水。第3圖爲習 知溶氮水的製造裝置的一例的步驟系統圖。從超純水槽25 利用泵26輸送出的超純水，在膜脫氣裝置27中被完全除去 溶存氣體，在膜式氣體溶解裝置28中被溶解指定量的氮氣， 製造指定濃度的溶氮水。 . 用於電子材料等洗淨的超純水，爲了脫氧及脫二氧化碳 ® 的目的而進行脫氣處理，在除去溶存氣體後，多有蓄積在上 部空間保持爲環境氣體的儲槽內的情況。在該種情況，因爲 在超純水中溶解有某種程度的氮，因此在藉由脫氣處理完全 除去溶存氮後，供給必要量之氮而使其溶解之方法’使得步 驟增加而多造成浪費。因此需求一種可簡單且精度良好製造 溶存氮濃度經控制之水的手段。 【發明內容】 (發明所欲解決之問題） 200536600 本發明之目的在於提供一種可簡單且精度良好地製造 溶存氮濃度經控制的水之溶氮水之製造裝置° (解決問題之手段） 本發明者等爲解決上述課題，經反覆刻意硏究的結果’ 發現了藉由將原水供給膜式氣體溶解裝置的水室’測定氣室 壓力，自動計算與對應溶氮水之指定濃度的設定値的差’以 使氣室壓力維持爲設定値的方式控制對氣室的供氮量’即可 穩定製造溶存氮濃度一定的溶氮水的方法，並基於該發現完 _成了本發明。 亦即，本發明提供 (1) 一種溶氮水之製造裝置，其特徵爲具備： (A) —具備由透氣性膜所區隔的水室與氣室的膜式氣體 溶解裝置；（B) —用於將被脫氧之水供給該水室的脫氧水供 給管；（C) 一用於從該水室排放溶氣體水的溶氣體水排放 管；（D)—用於將氮氣供給該氣室的供氮管；（E)—用於調整 供給氣室的供氮量的供氮量調整手段；及（F) —用於測定該 ♦ 氣室壓力的壓力計；並基於該壓力計之測定値，藉由供氮量 調整手段調整供氮量，將該氣室壓力維持爲設定値；及 (2) 如（1)記載之溶氮水之製造裝置，其中水爲超純水。 (發明效果） 藉由使用本發明裝置，以簡短步驟且不浪費氮氣，可穩 定且精度良好地製造溶存氮濃度經控制之溶氮水。 【實施方式】 本發明之溶氮水之製造裝置，其具備：（A)—具備由透 200536600 氣性膜所區隔的水室與氣室的膜式氣體溶解裝置；（B) —用 於將被脫氧之水供給該水室的脫氧水供給管；（C)一用於從 該水室排放溶氣體水的溶氣體水排放管；（D)—用於將氮氣 供給該氣室的供氮管；（E ) —用於調整供給氣室的供氮量的 供氮量調整手段；及（F) —用於測定該氣室壓力的壓力計； 並基於該壓力計之測定値，藉由供氮量調整手段調整供氮 量，將該氣室壓力維持在設定値。 第1圖爲本發明之溶氮水的製造裝置的一態樣的步驟系 # 統圖。在本態樣之裝置中，在超純水槽1內蓄積有被脫氧之 超純水。藉由將超純水脫氧，可防止洗淨之被洗淨物表面之 氧化，同時還可防止水中的生菌的繁殖。在脫氧處理時，在 水中進行離子化處理，同時還除去成爲增高電傳導率之原因 的二氧化碳。蓄積有被脫氧之超純水的超純水槽1的上部空 間，充滿了氮氣。因此，雖在超純水中溶解有某種程度的氮， 但大致無溶解達飽和濃度以上之氮的情況。槽內之超純水的 溶存氮濃度，隨槽內之場所而有差異，還隨超純水在槽內的 • 滯留時間而變動，幾乎在所有情況均未被控制。 超純水槽內的超純水係藉由泵2而經由脫氧水供給管 3，而被送入具備由透氣性膜所區隔的水室與氣室的膜式氣 體溶解裝置4。在膜式氣體溶解裝置設有將氮氣供給該氣室 的供氮管5及測定該氣室壓力的壓力計6。在膜式氣體溶解 裝置中，透過透氣性膜將氮溶解於超純水中，並將溶氮水從 溶氣體水排放管7排出。壓力計之測定値作爲信號被送入控 制器8，在控制器中自動計算與設定値的差，將信號送入閥 200536600 9 ’並藉由閥開啓度調整供氮量，將氣室內之壓力維持在設 定値。亦即，控制器8與閥9係作爲供氮量調整手段進行工 作。 當膜式氣體溶解裝置之氣室充滿了氮氣，其壓力爲標準 大氣壓之OkPa(計示壓力）時，溶氮水之溶存氮濃度成爲飽 和。例如，當爲溫度2 0 °C、大氣壓1 . 3 kP a時，獲得溶解 有氮19.0mg/L的溶氮水。當將氣室完全真空，而成爲壓力 -101.3 kP a(計示壓力）時，從水室排出之水的溶存氮濃度成 ® 爲0mg/L。當氮對溫度t °C之水的飽和溶解度爲Amg/L時， 當將膜式氣體溶解裝置之氣室壓力設爲-101.3 kPa(計示壓 力）的X倍（OS 1)時，從溶氣體水排放管排出之溶氮水之 溶存氮濃度成爲at(l-x)mg/L。利用該關係，藉由以氣室壓 力成爲設定値的方式供給氮，可製造指定溶存氮濃度的溶氮 水。膜式氣體溶解裝置之氣室壓力，係以在較供給氮之操作 點最遠之位置所測定者爲較佳。 根據本發明裝置，藉由調整充滿氮之膜式氣體溶解裝置 ® 之氣室壓力而維持爲設定値，即使供給之脫氧水之溶存氮濃 度發生變動，仍可將經常穩定製造指定溶存氮濃度的溶氮 水。在屬習知技術之氮溶解步驟前進行脫氣處理的方法中， 係在暫時除去隨意溶解在原水中的氮後，使必要量之氮溶 解。被脫氧之超純水，僅將氮作爲溶存氣體隨意進行溶解， 因此無需除去此而予以運用，可簡化溶氮水之製造裝置’而 在利用上不致浪費氮。 在本發明之溶氮水之製造裝置中，（G)可設有從氣室排 200536600 出氣體的排氣管。在第1圖所示態樣中，在膜式氣體溶解裝 置之氣室設有排氣管10，在排氣管設有閥11及泵12。排氣 管係在開始本發明裝置之運行時，在將氮氣送入氣室而由氮 氣取代內部的空氣時，可使用混合有空氣的排氣。另外，在 製造之溶氮水之溶存氮濃度，較由超純水槽所供給的超純水 的溶存氮濃度還要低的情況，可用於排出經由透氣膜而透過 的氮。 本發明裝置中，在製造之溶氮水之溶存氮濃度，較由超 ® 純水槽所供給的超純水的溶存氮濃度還要低的情況，膜式氣 體溶解裝置之氣室壓力，隨製造溶氮水而上升。此時，壓力 計6之測定値被作爲信號送入控制器8，在控制器自動計算 與設定値的差，將信號送入閥1 1，並藉由打開閥以調整排氮 量，將氣室內之壓力維持爲設定値。較閥1 1下游側，係由 泵1 2保持爲大氣壓以下。 爲藉由本發明裝置製造溶存氮濃度一定的溶氮水，可將 測定膜式氣體溶解裝置之氣室壓力的壓力計設於氣室，另 ^ 外，因爲將壓力計設於氣室，因此不需要使用試樣水的測 定，不需要採取試樣水用的分叉管，而可簡化溶氮水之製造 裝置。又，因爲僅僅測定壓力，因此不需要如溫度計的繁雜 操作，也不產排水。 本發明之裝置中，若將被脫氧之超純水設爲原水時，則 氮以外之氣體不會溶解，由壓力計測定之壓力直接對應於溶 氮水之溶存氮濃度，而可正確控制溶氮水之溶存氮濃度。另 外，供給膜式氣體溶解裝置之氣室的氮，通常爲純度1 00體 -10- .200536600 積％的氣體，因此其壓力測定値對應於溶存氮濃度。換言之， 使用原水中被脫氧之超純水，且使用供給之氮爲純度1 〇〇體 積％的氣體，因此藉由測定氣室壓力，即可製造指定溶存氮 濃度的溶氮水。 本發明之裝置中，作爲原水使用之被脫氧之超純水的溶 存氧濃度，以l〇〇Mg/L以下爲較佳。當溶存氧濃度爲100/xg/L 以下時，在測定對應溶存氧濃度的壓力的基礎上，溶存氧濃 度實質上未供給影響。若從超純水製造步驟所供給的超純水 # 的溶存氧濃度爲l〇〇Mg/L以下時，即可直接作爲溶氮水之原 水使用。在溶存氧濃度實高的情況，可進行脫氣用以除氧。 本發明之裝置中，當供給膜式氣體溶解裝置之超純水， 在超純水製造步驟或供給途中的超純水槽而由氮進行純化 時，將溶解有氮之超純水供給膜式氣體溶解裝置，但本發明 之裝置中，該預先溶解之氮也可作爲溶存氮使用，用以補充 不足的氮。 用於本發明裝置之透氣膜之材質雖無特別的限制，但例 • 如可舉出聚丙烯、聚（4_甲基戊烯-1)、聚（2,6-二甲基苯醚）、 聚二甲基矽氧烷、聚碳酸酯-聚二甲基矽氧烷嵌段共聚物、 聚乙烯基酚-聚二甲基矽氧烷-聚颯嵌段共聚物、聚四氟乙 烯、聚醯亞胺等。本發明之裝置中，因爲溶解無腐蝕性等之 氮，因此以使用聚丙烯、聚（4-甲基戊烯-1)等的聚烯系透氣 性膜爲較佳。本發明之裝置中，對透氣性膜知形式並無特別 的限制，例如，可舉出平面膜、管型、螺旋型、中空線型、 單片型、槽浸漬型、旋轉圓盤膜等。 -11- 200536600 本發明之裝置中，脫氧水及氮對膜式氣體溶解裝置之供 給，以對流方式進行者爲較佳。亦即，相對於朝膜式氣體溶 解裝置之水室之膜的長度方向一端側供給超純水，且從另一 端側排出溶氮水，則以氮氣係從氣室的溶氮水排出側供給， 且從超純水供給側排出爲較佳。藉由使超純水與氮對流接 觸，可獲得良好之氣體溶解效率。 第2圖爲本發明之溶氮水的製造裝置的另一態樣的說明 圖。本態樣中，膜式氣體溶解裝置係使用中空線膜型氣體溶 • 解裝置1 3，朝中空線膜1 4內側供給氮，朝中空線膜1 4外側 供給超純水。在膜式氣體溶解裝置一端介由分隔板1 7設有 供氣室1 5，而於另一端介由分隔板1 8設有排氣室1 6，中空 線係穿通分隔板而於供氣室及排氣室開口。從氮氣源1 9經 由流量調節閥20，將供氮管2 1連接於供氣室。另外，排氣 管22連接於排氣室。藉由壓力計23測定排氣室之壓力，將 壓力計之測定値作爲信號被送入控制器24，在控制器中自動 計算與設定値的差，將信號送入流量調節閥，並藉由閥開啓 ® 度調整排氮量，將中空線膜內側之壓力維持爲設定値。 本發明之裝置中，對設於膜式氣體溶解裝置之氣室的壓 力計並無特別的限制，例如，可舉出U字型管、單管型、零 位法型等的液柱方式壓力計，彈簧金屬曲管型、波紋管型、 隔膜型等的彈性體方式或力平衡方式的壓力計，單鐘式、複 鐘式等的沉鐘方式的壓力計等。 本發明之裝置中，對供氮量調整手段並無特別的限制， 例如，藉由手動或自動方式，可以壓力之測定値成爲對應指 200536600 定溶存氮濃度的設定値的方式調整供氮量。在以自動方式調 整供氮量的情況，將壓力測定値輸入演算裝置，與壓力設定 値進行比較演算，將相當於該差値的信號送入供氮量調整手 段，便可調整供氮量。供氮量調整手段，如可舉出設於供氮 管或排氮管的流量調整閥等。在以手動方式調整供氮量的情 況，可通過人工調整閥的開啓度。 [實施例] 以下，以實施例爲例進一步詳細說明本發明，但本發明 ® 並不受此等實施例限制。 (實施例υ 使用第1圖所示裝置，在2(TC下製造溶存氮濃度12 mg/L的溶氮水。膜式氣體溶解裝置係具備聚丙烯中空線之 外形尺寸爲直徑1 2 0 m m，長度8 3 5 m m的膜模組。 從超純水槽1將溶存氮濃度7.6 mg/L的超純水，通過 泵2且以20L/分鐘送入膜式筚體溶解裝置4的水室，且通過 壓力計6及閥9來控制供氮量，使其膜式氣體溶解裝置的氣 ^ 室壓力成爲-37kPa(錶壓）。使其供氮量成爲70mL(標準狀態）/ 分鐘，從膜式氣體溶解裝置流出的溶氮水的氮濃度爲 12.0mg/L。供給膜式氣體溶解裝置的氮70mL(標準狀態）/分 鐘，與超純水20L/分鐘的溶存氮濃度之增加量4.4 mg/L — 致，確認到供給膜式氣體溶解裝置的氮被消耗在超純水的溶 存氮濃度之增加量上。 (實施例2) 與實施例1相同製造溶存氮濃度7.6 mg/L的溶氮水。 ,200536600 除通過壓力計6及閥9來控制供氮量，使其膜式氣體溶解裝 置的氣室壓力成爲-21 kP a(錶壓）外，其餘與實施例1相同進 行操作。使其供氮量成爲U8mL(標準狀態）/分鐘，從膜式氣 體溶解裝置流出的溶氮水的氮濃度爲15.0mg/L。供給膜式氣 體溶解裝置的氮U8mL(標準狀態）/分鐘，與超純水20L/分 鐘的溶存氮濃度之增加量7.4 mg/L —致，確認到供給膜式 氣體溶解裝置的氮被消耗在超純水的溶存氮濃度之增加量 上。 • 從實施例1及實施例2之結果可知，在20°C下，以膜式 氣體溶解裝置的氣室壓力成爲-101.3kPa(錶壓）的0.37倍或 0.2 1倍的方式進行控制，將氮氣供給氣室，可獲得溶存氮濃 度爲飽和濃度1 9.0 mg/L的0.63倍或0.79倍的溶氮水。因 此即使供給膜式氣體溶解裝置之水室的超純水之溶存氮濃 度發生變動，以膜式氣體溶解裝置之壓力成爲設定値的方式 進行控制，將氮氣供給膜式氣體溶解裝置之氣室，仍可製造 指定溶存氮濃度的溶氮水。 •(產業上之可利用性） 藉由使用本發明溶氮水之製造裝置，將溶解有氮之超純 水作爲原水，對指定之溶存氮濃度溶解不足量之氮，即可以 簡短步驟簡單且精度良好地製造溶存氮濃度經控制之溶氮 水。 【圖式簡單說明】 第1圖爲本發明之溶氮水的製造裝置的一態樣的步驟系 統圖。 -14- 200536600 第2圖爲本發明之溶氮水的製造裝置的另一態樣的說明 圖。 第3圖爲習知溶氮水的製造裝置的一例的步驟系統圖。 【元件符號說明】 1 超純水槽 2 泵 3 脫氧水供給管 4 膜式氣體溶解裝置 • 5 供氮管 6 壓力計 7 溶氣體水排放管 8 控制器 9 閥 10 排氣管 11 閥 12 泵 ® 13 中空線膜型氣體溶解裝置 14 中空線膜 15 供氣室 16 排氣室 17 分隔板 18 分隔板 19 氮氣源 20 流量調節閥 200536600 2 1 供氮管 22 排氣管 23 壓力計 24 控制器 25 超純水槽 26 泵 27 膜脫氣裝置 28 膜式氣體溶解裝置200536600 IX. Description of the invention: [Technical field to which the invention belongs] The present invention relates to a device for manufacturing nitrogen-dissolved water. More specifically, the present invention relates to a manufacturing apparatus for nitrogen-soluble water that can easily and accurately produce water with a controlled dissolved nitrogen concentration. [Previous technology] The removal of foreign matter such as fine particles from the surface of electronic materials such as silicon substrates for semiconductors, glass substrates for liquid crystals, and quartz substrates for photomasks is extremely important in ensuring product quality and yield. In the case of cleaning electronic materials and the like by ultrasonic waves, it is found that a good cleaning effect can be obtained by using washing water in which a gas is dissolved. Generally, the higher the dissolved nitrogen concentration, the better. However, if it becomes supersaturated, excess air bubbles will be generated. This will hinder the propagation of ultrasonic waves, or cause adhesion to the surface of the object to be washed. . When a nozzle with a built-in vibration plate is used, accumulated gas is formed inside the nozzle, which not only prevents ultrasonic waves from propagating into the water, but also causes damage to the ultrasonic oscillating portion. Therefore, there is a need for a high-concentration dissolved gas water in a range where the dissolved nitrogen concentration does not reach supersaturation. In order to remove fine particles, ultrasonic washing using oxygen-dissolved washing water is most effective. However, in view of convenience of gas operation, nitrogen-dissolved water in which nitrogen is dissolved is mostly used. Examples of the means for dissolving nitrogen in ultrapure water include nitrogen boiling in a water tank. This method is very simple, but it is difficult to maintain the dissolved nitrogen concentration with high precision and accuracy. There is also a simple gas dissolving technology using a breathable membrane module. If a gas-permeable membrane module is used, it is relatively easy to obtain nitrogen-dissolved water with a high dissolved nitrogen concentration, but it is difficult to stably produce a nitrogen-dissolved water with a certain concentration of dissolved nitrogen and that is not oversaturated by 200536600. On the other hand, a method is also known in which ultrapure water and nitrogen gas are supplied to a gas dissolving device, and the dissolved nitrogen concentration of the nitrogen-dissolved water obtained by measuring a nitrogen concentration meter is compared with a target nitrogen concentration to control the amount of nitrogen supplied. However, in the measurement of the conventional nitrogen concentration meter, it is quite troublesome to set the operating conditions such as the supply of the exhaust gas to the meter and the adjustment of the flow rate of the sample water. In addition, the meter is equipped with a branch pipe for the sample, so To be cumbersome and time-consuming, the sample water must be drained frequently and wasteful. Φ After completely removing the dissolved gas in the raw water by degassing treatment, the permeable membrane module is used to supply only the necessary amount of the specific gas for dissolution, and water with a specified concentration of gas dissolved in the raw water can be produced without bubbles. Fig. 3 is a step system diagram of an example of a conventional apparatus for producing nitrogen-dissolved water. The ultrapure water sent from the ultrapure water tank 25 by the pump 26 is completely removed by the membrane degassing device 27, and the membrane gas dissolving device 28 is dissolved with a specified amount of nitrogen to produce a nitrogen solution with a specified concentration. . Ultra-pure water used for washing electronic materials is degassed for the purpose of deoxidation and carbon dioxide removal. After removing dissolved gas, it is often stored in a storage tank in which the upper space is maintained as an ambient gas. In this case, because nitrogen is dissolved to some extent in ultrapure water, a method of supplying a necessary amount of nitrogen to dissolve it after the dissolved nitrogen is completely removed by a degassing treatment causes a large increase in the number of steps and causes waste. Therefore, there is a need for a simple and accurate method for producing water with a controlled concentration of dissolved nitrogen. [Summary of the Invention] (Problems to be Solved by the Invention) 200536600 The object of the present invention is to provide a device for producing nitrogen-soluble water that can simply and accurately control water with a dissolved nitrogen concentration controlled by the invention. In order to solve the above-mentioned problems, they repeatedly deliberately researched and found that 'the source of raw water was supplied to the water chamber of the membrane-type gas dissolving device', the pressure of the gas chamber was measured, and the value corresponding to the set concentration of the dissolved nitrogen water was automatically calculated. A method of stably producing nitrogen-dissolved water having a constant dissolved nitrogen concentration by controlling the amount of nitrogen supplied to the gas chamber such that the pressure of the gas chamber is maintained at a predetermined value, and completed the present invention based on this finding. That is, the present invention provides (1) a device for producing nitrogen-dissolved water, comprising: (A) a membrane-type gas dissolving device including a water chamber and an air chamber separated by a gas-permeable membrane; (B) -A deoxidized water supply pipe for supplying deoxidized water to the water chamber; (C) a dissolved gas water discharge pipe for discharging dissolved gas water from the water chamber; (D)-used for supplying nitrogen to the gas Chamber nitrogen supply pipe; (E) —a nitrogen supply amount adjusting means for adjusting the nitrogen supply amount to the air chamber; and (F) —a pressure gauge for measuring the pressure of the air chamber; and based on the pressure gauge, Measure radon, adjust the nitrogen supply amount by means of nitrogen supply amount adjustment means, and maintain the gas chamber pressure at the set value; and (2) the apparatus for producing nitrogen-dissolved water according to (1), wherein the water is ultrapure water. (Effects of the Invention) By using the device of the present invention, nitrogen-dissolved water having a controlled concentration of dissolved nitrogen can be produced stably and accurately with short steps without wasting nitrogen. [Embodiment] The device for producing nitrogen-dissolved water according to the present invention includes: (A) —a membrane-type gas dissolving device including a water chamber and an air chamber separated by a gas-permeable membrane of 200536600; (B) —for A deoxidized water supply pipe for supplying deoxidized water to the water chamber; (C) a dissolved gas water discharge pipe for discharging dissolved gas water from the water chamber; (D) —a supply for supplying nitrogen gas to the gas chamber Nitrogen tube; (E)-a nitrogen supply amount adjusting means for adjusting the nitrogen supply amount to the gas chamber; and (F)-a pressure gauge for measuring the pressure of the gas chamber; and based on the measurement of the pressure gauge, borrow The nitrogen supply amount is adjusted by a nitrogen supply amount adjustment means, and the pressure of the air chamber is maintained at a set value. FIG. 1 is a step system diagram of one aspect of an apparatus for producing nitrogen-soluble water according to the present invention. In the apparatus of this aspect, deoxidized ultrapure water is accumulated in the ultrapure water tank 1. By deoxidizing the ultrapure water, it is possible to prevent oxidation of the surface of the object to be cleaned, and to prevent the proliferation of bacteria in the water. At the time of deoxidation, ionization treatment is performed in water, and at the same time, carbon dioxide, which is a cause of increasing electric conductivity, is removed. The upper space of the ultrapure water tank 1 in which deoxidized ultrapure water is accumulated is filled with nitrogen. For this reason, although nitrogen is dissolved to some extent in ultrapure water, it is almost impossible to dissolve nitrogen above the saturation concentration. The dissolved nitrogen concentration of ultrapure water in the tank varies with the location of the tank, and also varies with the residence time of the ultrapure water in the tank, which is almost uncontrolled in all cases. The ultrapure water in the ultrapure water tank is sent to a membrane-type gas dissolving device 4 having a water chamber and an air chamber separated by a gas-permeable membrane through a deoxidized water supply pipe 3 through a pump 2. The membrane gas dissolving device is provided with a nitrogen supply pipe 5 for supplying nitrogen to the gas chamber and a pressure gauge 6 for measuring the pressure in the gas chamber. In the membrane-type gas dissolving device, nitrogen is dissolved in ultrapure water through a gas-permeable membrane, and nitrogen-dissolved water is discharged from the gas-dissolved water discharge pipe 7. The measurement 値 of the pressure gauge is sent to the controller 8 as a signal, and the difference between the set value and the set 自动 is automatically calculated in the controller. The signal is sent to the valve 200536600 9 ′ and the nitrogen supply is adjusted by the valve opening degree to increase the pressure in the gas chamber. Keep at setting 値. That is, the controller 8 and the valve 9 work as a means for adjusting the amount of nitrogen supply. When the gas chamber of the membrane gas dissolving device is filled with nitrogen and its pressure is OkPa (gauge pressure) of standard atmospheric pressure, the dissolved nitrogen concentration of the dissolved nitrogen water becomes saturated. For example, at a temperature of 20 ° C and an atmospheric pressure of 1.3 kPa, nitrogen-dissolved water in which 19.0 mg / L of nitrogen is dissolved is obtained. When the air chamber is completely evacuated to a pressure of -101.3 kP a (calculated pressure), the dissolved nitrogen concentration of the water discharged from the water chamber becomes 0 mg / L. When the saturated solubility of nitrogen to water at temperature t ° C is Amg / L, when the gas chamber pressure of the membrane gas dissolving device is set to X times (OS 1) -101.3 kPa (gauge pressure), The dissolved nitrogen concentration of the nitrogen-dissolved water discharged from the gas water discharge pipe becomes at (lx) mg / L. Using this relationship, by supplying nitrogen such that the pressure of the air chamber becomes a predetermined pressure, nitrogen-dissolved water having a specified dissolved nitrogen concentration can be produced. The gas chamber pressure of the membrane gas dissolving device is preferably measured at a position farthest from the operating point where nitrogen is supplied. According to the apparatus of the present invention, the gas chamber pressure of the membrane-type gas dissolving device® filled with nitrogen is maintained at a setting value of 値, and even if the dissolved nitrogen concentration of the supplied deoxygenated water changes, the specified dissolved nitrogen concentration can still be stably produced. Dissolved nitrogen water. In the method of performing a degassing treatment before the nitrogen dissolving step, which is a conventional technique, a necessary amount of nitrogen is dissolved after temporarily removing nitrogen that is optionally dissolved in raw water. The deoxygenated ultrapure water only dissolves nitrogen as a dissolved gas at will, so it can be used without removing it. This simplifies the production equipment of nitrogen-dissolved water 'and does not waste nitrogen in utilization. In the device for producing nitrogen-dissolved water of the present invention, (G) may be provided with an exhaust pipe for discharging the gas from the air chamber 200536600. In the state shown in Fig. 1, an exhaust pipe 10 is provided in the gas chamber of the membrane gas dissolving device, and a valve 11 and a pump 12 are provided in the exhaust pipe. When the exhaust pipe is started in the operation of the device of the present invention, when nitrogen gas is sent into the gas chamber and the internal air is replaced by nitrogen gas, an exhaust gas mixed with air can be used. In addition, when the dissolved nitrogen concentration of the produced nitrogen-dissolved water is lower than the dissolved nitrogen concentration of the ultrapure water supplied from the ultrapure water tank, it can be used to discharge the nitrogen that has passed through the air-permeable membrane. In the device of the present invention, the dissolved nitrogen concentration of the manufactured nitrogen-dissolved water is lower than the dissolved nitrogen concentration of the ultra-pure water supplied from the ultra-pure water tank. Dissolved in nitrogen water and rose. At this time, the measurement 値 of the pressure gauge 6 is sent to the controller 8 as a signal. The controller automatically calculates the difference from the set 値, sends the signal to the valve 11 and opens the valve to adjust the amount of nitrogen discharged. The pressure in the room is maintained at the set value. It is maintained at a pressure below atmospheric pressure by the pump 12 below the valve 11 downstream. In order to produce dissolved nitrogen with a certain dissolved nitrogen concentration by the device of the present invention, a pressure gauge for measuring the pressure of the gas chamber of the membrane gas dissolving device can be provided in the gas chamber. In addition, because the pressure gauge is provided in the gas chamber, It is necessary to use sample water for measurement, and it is not necessary to use a branching tube for sample water, which can simplify the device for manufacturing nitrogen-dissolved water. In addition, since only the pressure is measured, a complicated operation such as a thermometer is not required, and drainage is not produced. In the device of the present invention, when deoxidized ultrapure water is used as raw water, gases other than nitrogen will not dissolve, and the pressure measured by the pressure gauge directly corresponds to the dissolved nitrogen concentration of the dissolved nitrogen water, and the dissolved nitrogen can be controlled accurately. Dissolved nitrogen concentration in water. In addition, the nitrogen supplied to the gas chamber of the membrane gas dissolving device is usually a gas having a purity of 100 body -10- .200536600% by volume, so its pressure measurement corresponds to the dissolved nitrogen concentration. In other words, by using ultra-pure water that has been deoxidized in raw water, and using nitrogen gas having a purity of 100% by volume, it is possible to produce a nitrogen-dissolved water having a specified dissolved nitrogen concentration by measuring the pressure of the gas chamber. In the device of the present invention, the dissolved oxygen concentration of the deoxygenated ultrapure water used as raw water is preferably 100 Mg / L or less. When the dissolved oxygen concentration is 100 / xg / L or less, after measuring the pressure corresponding to the dissolved oxygen concentration, the dissolved oxygen concentration is not substantially affected. If the dissolved oxygen concentration of the ultrapure water # supplied from the ultrapure water production step is 100 Mg / L or less, it can be used directly as the raw water of nitrogen-dissolved water. When the dissolved oxygen concentration is really high, degassing can be performed to remove oxygen. In the device of the present invention, when ultrapure water supplied to the membrane gas dissolving device is purified by nitrogen in the ultrapure water manufacturing step or in the ultrapure water tank in the supply process, ultrapure water in which nitrogen is dissolved is supplied to the membrane gas. Dissolving device, but in the device of the present invention, the previously dissolved nitrogen can also be used as dissolved nitrogen to supplement insufficient nitrogen. Although the material of the breathable film used in the device of the present invention is not particularly limited, examples include polypropylene, poly (4-methylpentene-1), and poly (2,6-dimethylphenyl ether). , Polydimethylsiloxane, polycarbonate-polydimethylsiloxane block copolymer, polyvinylphenol-polydimethylsiloxane, polyfluorene block copolymer, polytetrafluoroethylene, Polyimide and so on. In the device of the present invention, since non-corrosive nitrogen is dissolved, a polyolefin-based air-permeable film such as polypropylene or poly (4-methylpentene-1) is preferably used. In the device of the present invention, the known form of the breathable film is not particularly limited, and examples thereof include a flat film, a tube type, a spiral type, a hollow linear type, a single-piece type, a groove-impregnated type, and a rotating disc film. -11- 200536600 In the device of the present invention, the supply of deoxidized water and nitrogen to the membrane gas dissolving device is preferably performed by convection. That is, the ultra-pure water is supplied to one end side of the film in the water chamber of the membrane-type gas dissolving device in the longitudinal direction, and the nitrogen-dissolved water is discharged from the other end side. It is more preferable to discharge from the ultrapure water supply side. By convecting ultrapure water with nitrogen, good gas dissolution efficiency can be obtained. Fig. 2 is a diagram illustrating another aspect of the apparatus for producing nitrogen-soluble water according to the present invention. In this aspect, the membrane-type gas dissolving device uses a hollow wire membrane gas dissolving device 13 to supply nitrogen to the inside of the hollow wire membrane 14 and ultrapure water to the outside of the hollow wire membrane 14. A gas supply chamber 15 is provided at one end of the membrane gas dissolving device through a partition plate 17 and an exhaust chamber 16 is provided at the other end through a partition plate 18. The hollow wire passes through the partition plate and Air supply and exhaust chamber openings. A nitrogen supply pipe 21 is connected to the gas supply chamber from a nitrogen source 19 through a flow regulating valve 20. The exhaust pipe 22 is connected to an exhaust chamber. The pressure of the exhaust chamber is measured by the pressure gauge 23, and the measurement 値 of the pressure gauge is sent as a signal to the controller 24, and the difference between the set 値 and the set 控制器 is automatically calculated in the controller, and the signal is sent to the flow regulating valve. The valve opening degree adjusts the amount of nitrogen exhausted and maintains the pressure inside the hollow membrane to the set value. In the device of the present invention, the pressure gauge provided in the gas chamber of the membrane gas dissolving device is not particularly limited. For example, U-shaped tube, single tube type, and zero-position type liquid column pressure can be cited. Pressure gauges, such as spring metal curved tube type, corrugated tube type, diaphragm type, and other pressure gauges of the elastomer type or force balance type, and single bell type and complex bell type pressure gauges. In the device of the present invention, there is no particular limitation on the means for adjusting the amount of nitrogen supplied. For example, by manual or automatic means, the pressure measurement can be performed in a manner corresponding to the setting of 200536600 to determine the concentration of dissolved nitrogen. When the nitrogen supply is adjusted in an automatic way, the pressure measurement 値 is input to the calculation device, and the calculation is compared with the pressure setting ，, and a signal equivalent to the rate is sent to the nitrogen supply adjustment means to adjust the nitrogen supply. Examples of the means for adjusting the nitrogen supply amount include a flow adjustment valve provided in a nitrogen supply pipe or a nitrogen discharge pipe. In the case of manual adjustment of the nitrogen supply, the valve opening can be adjusted manually. [Examples] Hereinafter, the present invention will be described in further detail by taking examples as examples, but the present invention is not limited by these examples. (Example υ) The apparatus shown in Fig. 1 was used to produce nitrogen-dissolved water with a dissolved nitrogen concentration of 12 mg / L at 2 ° C. The membrane-type gas dissolving device is equipped with a polypropylene hollow wire and the outer dimension is 120 mm in diameter. A membrane module with a length of 8 3 5 mm. Ultra-pure water with a dissolved nitrogen concentration of 7.6 mg / L is sent from the ultra-pure water tank 1 to the water chamber of the membrane-type carcass dissolution device 4 through the pump 2 at 20 L / min. And the nitrogen supply is controlled by the pressure gauge 6 and the valve 9 so that the chamber pressure of the membrane gas dissolving device becomes -37 kPa (gauge pressure). The nitrogen supply is 70 mL (standard state) / minute. The nitrogen concentration of the nitrogen-dissolved water flowing out of the gas-type gas dissolving device is 12.0mg / L. The amount of nitrogen supplied to the membrane gas-dissolving device is 70mL (standard state) / minute, and the dissolved nitrogen concentration of ultra-pure water is 20L / minute. It is confirmed that the nitrogen supplied to the membrane gas dissolving device is consumed by the increase in the dissolved nitrogen concentration of ultrapure water. (Example 2) A dissolved nitrogen concentration of 7.6 mg / L was produced in the same manner as in Example 1. Nitrogen water, 200536600 In addition to controlling the amount of nitrogen supplied by the pressure gauge 6 and valve 9, the gas of the membrane gas dissolving device Except that the pressure became -21 kP a (gauge pressure), the rest was operated in the same manner as in Example 1. The nitrogen supply amount was U8 mL (standard state) / minute, and the nitrogen concentration of the dissolved nitrogen water flowing from the membrane gas dissolving device was 15.0mg / L. Nitrogen U8mL (standard state) / minute supplied to the membrane gas dissolving device, the increase in dissolved nitrogen concentration with ultrapure water 20L / min is 7.4 mg / L. It is confirmed that the membrane gas dissolving device is supplied. Nitrogen is consumed by the increase in the dissolved nitrogen concentration of ultrapure water. • From the results of Example 1 and Example 2, it is known that the gas chamber pressure of the membrane gas dissolving device at -101.3 kPa at 20 ° C (Gauge pressure) is controlled by 0.37 times or 0.2 1 times. Supplying nitrogen gas to the gas chamber can obtain dissolved nitrogen with a dissolved nitrogen concentration of 0.63 times or 0.79 times the saturated concentration of 1 9.0 mg / L. Therefore, even if the membrane is supplied, The dissolved nitrogen concentration of the ultrapure water in the water chamber of the gas-type gas dissolving device changes, and the pressure of the membrane gas-dissolving device is controlled so that the nitrogen gas is supplied to the gas chamber of the membrane-type gas dissolving device. Dissolved nitrogen • (Industrial availability) By using the nitrogen-dissolved water manufacturing device of the present invention, ultra-pure water in which nitrogen is dissolved is used as raw water to dissolve an insufficient amount of nitrogen at a specified dissolved nitrogen concentration. The dissolved nitrogen water with controlled dissolved nitrogen concentration can be produced with high accuracy. [Simplified description of the drawing] Fig. 1 is a step-by-step system diagram of one aspect of the apparatus for producing dissolved nitrogen water according to the present invention. -14- 200536600 Fig. 2 FIG. 3 is a diagram illustrating another aspect of the apparatus for producing nitrogen-dissolved water according to the present invention. FIG. 3 is a step system diagram of an example of a conventional apparatus for producing nitrogen-dissolved water. [Description of component symbols] 1 Ultra-pure water tank 2 Pump 3 Deoxygenated water supply pipe 4 Membrane gas dissolving device • 5 Nitrogen supply pipe 6 Pressure gauge 7 Dissolved gas water discharge pipe 8 Controller 9 Valve 10 Exhaust pipe 11 Valve 12 Pump® 13 Hollow wire membrane type gas dissolving device 14 Hollow wire membrane 15 Gas supply chamber 16 Exhaust chamber 17 Sub-partition 18 Sub-partition 19 Nitrogen source 20 Flow control valve 200536600 2 1 Nitrogen supply pipe 22 Exhaust pipe 23 Pressure gauge 24 Control Device 25 ultrapure water tank 26 pump 27 membrane degassing device 28 membrane gas dissolving device
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